January 12-16, 2025 (National Harbor, MD)

Town Hall: Nancy Grace Roman Space Telescope Town Hall

• Nancy Grace Roman Space Telescope

  (Tuesday, January 14, 6:30–8:00 p.m. ET)

  The Nancy Grace Roman Space Telescope is a NASA flagship mission planned for launch no later than May 2027. The Roman Space Telescope will perform breakthrough science in dark energy cosmology, exoplanet microlensing, and NIR sky surveys with its Wide Field Instrument. Roman will also feature the Coronagraph Instrument (CGI), a technology demonstration that will directly image and take spectra of exoplanetary systems using several novel technologies together for the first time in space. This session will cover the status of the project and upcoming opportunities for community involvement in planning and executing the science and technology demonstration aspects of Roman. For more details please see: https://roman.gsfc.nasa.gov/AAS245/.

 

Workshops

• Python Data Analysis with the James Webb and Roman Space Telescopes

(Sunday, January 12, 9:00–5:00 p.m. ET)

This workshop will cover several tools used for the data analysis and visualization of JWST and Roman data. This includes the Jdaviz visualization and data analysis package, the Advanced Scientific Data Format (ASDF) package, specreduce, photutils PSF photometry, and generalized world coordinate systems (gwcs). The goals are to introduce participants to these tools and provide hands-on time for participants to use the tools and ask questions to the developers. The format will include short presentations followed by instructor-guided tutorials using Jupyter notebooks. Jdaviz is a package of astronomical data analysis visualization tools based on the Jupyter platform. These GUI-based tools link data visualization and interactive analysis. Presenters will provide examples of the latest features available in the various configurations (Specviz, Cubeviz, Imviz, and Specviz2d) and will guide attendees through basic and advanced workflows to analyze JWST spectra and images. The Advanced Scientific Data Format (ASDF) is a next-generation interchange format for scientific data. It will be used as the data format for Roman Space Telescope Level 1 - 4 data products. The workshop will also cover the Astropy packages specreduce (spectral extraction), photutils PSF photometry, and the generalized world coordinates system package (gwcs). There will be time spent on hands-on exercises. Participants must bring a laptop with the software installed. Instructions on installing the necessary software will be provided before the workshop and help will be available at the workshop for those that experience problems with installations. The prerequisites are a familiarity with astronomical data analysis. Basic Python experience is highly recommended to be able to participate in the exercises. Those without Python experience will still be able to use Jdaviz and gain useful information about the capabilities for data analysis in Python.

• Preparing for the Nancy Grace Roman Space Telescope: The New Cloud Science Platform

(Sunday, January 12, 9:00–5:00 p.m. ET)

The Nancy Grace Roman Space Telescope is anticipated to generate close to 30 petabytes of data during its five-year primary mission, heralding a new era of big data in astronomy. As data sets grow too large for personal computers, virtual science platforms offer a solution by providing cloud-based data processing and analysis. The Roman Science Platform is being developed to offer the astronomical community a cloud computing environment for Roman data. It couples data-code proximity with a pre-configured software environment, making it easier for users to work with data. The platform also includes pre-loaded notebook tutorials and scientific workflows tailored to specific astronomical use cases. Utilizing the JupyterLab environment, users can create Jupyter Notebooks that seamlessly integrate code, analysis results, data visualizations, and other functionalities for handling astronomical images and catalogs. This one-day workshop will provide the scientific community with an introductory overview of the Roman Science Platform. In addition to offering hands-on training, we aim to gather feedback, understand the needs of the user community, and identify ‘early adopters’ interested in utilizing the system for precursor science prior to the Roman launch. The workshop will include both directed training and independent exploration exercises (i.e., hack hours). The training will feature presentations and short tutorials, alternating with hands-on practical exercises focused on exploring several high-level workflows. Examples include an introduction to Roman data reduction tools, learning how to work with the ASDF file format, and using visualization and simulation tools such as Jdaviz (image visualization), Pandeia (Exposure Time Calculator), RIST (Roman Interactive Sensitivity Tool), STIPS (Space Telescope Image Product Simulator), and WebbPSF for Roman (PSFs simulator). Attendees will also learn how to access and analyze state-of-the-art Roman simulations from the Open Universe project (Troxel et al. 2023), which includes simulated wide-field and time-domain Roman data, as well as how to simulate their own data using Roman simulation tools. This course is aimed at astronomers and scientists at all stages of their education and careers. A basic knowledge of Python and familiarity with astronomical data concepts (e.g., data reduction, photometry) is expected. Prior experience with science platforms, Jupyter Notebooks, or the Roman mission is not required. This workshop requires registration. Participants will need personal computers and should set up their accounts in advance with help from the workshop organizers. A group list will be compiled approximately one month before the workshop to distribute software requirements and facilitate collaborative troubleshooting.

 

Oral Splinter Sessions

• Roman Spectroscopy Data Challenge (Part 1/3)

  (Monday, January 13, 10:00–11:30 a.m. ET)

  NASA’s Nancy Grace Roman Space Telescope, scheduled for launch by October 2026, will revolutionize astronomy with its widefield slitless spectroscopy capabilities. This technique captures spectra from every object in the field of view, enabling detailed studies of stars, galaxies, black holes, and the large-scale structure of the universe. As the mission approaches, the scientific community must be prepared to effectively handle and analyze this data, with the first call for proposals anticipated in fall 2025. This session is the first part of a Roman spectroscopic data challenge, and offers a gentle introduction to slitless spectroscopy, with a focus on the Roman Space Telescope's spectroscopic capabilities. This data challenge aims to: 1) Familiarize the community with Roman's powerful spectroscopic capabilities. 2) Develop, utilize, and enhance data simulation and analysis methods, including combining spectroscopy and imaging data, and using a variety of postprocessing techniques. 3) Train and foster collaborations among future users of Roman.

• Project Infrastructure Teams for the Roman Space Telescope

  (Tuesday, January 14, 9:00 a.m.–12:00 p.m. ET)

  The Nancy Grace Roman Space Telescope is NASA's next flagship mission in astrophysics. The Roman Project Infrastructure Teams (PITs) develop and maintain the infrastructural tools and capabilities needed to address the mission objectives and to support community science collaborations, in close collaboration with the Roman project and partnering with the Roman Science Centers at IPAC and STScI. At this splinter meeting, the Roman PITs will present detailed work plans and deliverables. This will inform the community about the tools being developed by the PITs for Roman science, and enable the PITs to benefit from community input. The Roman PITs competitively selected by NASA are: "Cosmology with the Roman High Latitude Imaging Survey", "Project Infrastructure for the Roman Galaxy Redshift Survey", "A Roman Project Infrastructure Team to Support Cosmological Measurements with Type Ia Supernovae", "The Roman Galactic Exoplanet Survey Project Infrastructure Team", and "RAPID: Roman Alerts Promptly from Image Differencing."

• Advancing the Roman Coronagraph Instrument to Flight: Project Status and Coronagraph Community Participation Program Activities

  (Tuesday, January 14, 10:00 a.m.-12:00 p.m. ET)

  In preparation for the operational phase of the Nancy Grace Roman Space Telescope, NASA has created the Coronagraph Community Participation Program (CPP) to prepare for and execute Coronagraph Instrument technology demonstration observations. The Coronagraph Instrument will provide the first-ever, in-space demonstrations of multiple key technologies that will be required by any future mission whose goals include the direct imaging and characterization of rocky planets in the habitable zones of nearby, sun-like stars, such as the Habitable Worlds Observatory (HWO), including ultra-precise wavefront sensing and control, and the use of large-format deformable mirrors in space. The Roman Coronagraph Instrument will not be sensitive to terrestrial planets, but will be capable of imaging giant planets in reflected, visible light, with potential sensitivity to true Jovian analogues. Additional, planned Coronagraph targets include imaging of exozodiacal dust and disks in visible wavelengths. The CPP is composed of 7 small, US-based teams, selected competitively via the Nancy Grace Roman Space Telescope Research and Support Participation Opportunity, members of the Roman Project Team, and international partner teams from ESA, JAXA, CNES, and the Max Planck Institute for Astronomy. The primary goals of the CPP are to prepare target, calibration, and reference star databases; to generate simulation and observation planning tools; and to implement the data reduction software for the execution of the Coronagraph Instrument observation phase. A second round of CPP teams is expected to be solicited in the upcoming D.14 ROSES call in early 2025. In this session, we will present the current status of the Coronagraph Instrument and planned, next steps before launch. The CPP will review its current status and describe plans and development timelines up through the nominal mission launch date (October 2026). A particular emphasis will be placed on current and planned tool development along with publicly available resources for the broad community. We will also present the results of the CPP Community Interest Survey, which solicited input from the broader astronomical community on CPP goals and the prioritization of planned Coronagraph Instrument observing sequences. Additionally, the session will include discussion of what we can expect to learn from the Roman Coronagraph that will be directly relevant to the development of HWO, as well as plans for developing and prioritizing observation sequences that directly inform future exoplanet imaging missions. The session will provide community members interested in joining or working with the CPP and opportunity to pose questions directly to current CPP participants.

• Maximizing Science with Roman-Rubin Data Synergies

  (Wednesday, January 15, 10:00 a.m.-11:30 a.m. ET)

  The NASA Nancy Grace Roman Space Telescope (Roman) and the Vera C. Rubin Observatory Legacy Survey of Space and Time (Rubin), will transform our view of the wide-field sky, with similar sensitivities, but complementary in wavelength, spatial resolution, and time domain coverage. A number of science topics can be uniquely addressed considering Roman and Rubin synergies in observing strategy, data products and archiving, joint analysis, and community engagement. With both surveys coming online soon, now is the time to start developing concrete and implementable plans. This AAS Splinter Session aims to bring together the Roman and Rubin community to provide an updated look at possible synergies, with a specific focus on the data sets themselves. The session will consider the most impactful strategies for co-processing the data from both observatories. Topics may include, but are not limited to, simple catalog matching, joint pixel-level processing, and combining time domain data sets. The format will include a combination of both talks and open space for discussion. The intention is to lay the ground-work for future workshops and planning activities within the community to ensure these ideas can become a reality. For an updated agenda and list of speakers, please check back often at the STScI Roman Outerspace Page for AAS 245: https://outerspace.stsci.edu/display/RAA2/Roman+at+AAS+Home.

• Enhancing the Science of the Roman Space Telescope with Simulations

  (Wednesday, January 15, 2:00 p.m.-3:30 p.m. ET)

  With a Wide Field Instrument (WFI) delivering Hubble-like resolution over roughly 100 times the instantaneous area, and an observatory designed to enable large-area surveys nearly three orders of magnitude faster than HST, the Nancy Grace Roman Space Telescope will produce expansive surveys that transform our understanding of dark energy, dark matter, galaxies, and exoplanets. In order to help plan for and take full advantage of the Roman surveys, as well as test data reduction and analysis algorithms currently being developed, it is essential to create detailed simulated Roman photometric, morphological and spectroscopic datasets. Roman will launch in late 2026 with data products publicly available in early 2027, making the availability and coordination of simulated Roman data in the community extremely timely. In that spirit, the Roman Simulations Working Group has recently formed with the goal of providing a forum to the community to coordinate simulation efforts and discussion of simulated data products and tools. This session will have a short introduction to the Simulations Working Group scope and goals and will bring together observers and theorists to discuss existing Roman simulation resources and plan for additional simulations to maximize the scientific return from Roman’s Core Community, Galactic Plane, and General Astrophysics surveys.

 

Oral Special Sessions

• NASA's Habitable Worlds Observatory

  Roman CGI and the HWO Coronagraph - B. Mennesen (NASA JPL)

  (Wednesday, January 15, 11:00–11:10 a.m. ET)

  (No abstract.)

• Open Science: NASA Astrophysics in the Roman Era

  (Wednesday, January 15, 2:00 p.m.-3:30 p.m. ET)

  US science agencies increasingly emphasize open-source science -- accelerating scientific progress by open sharing of data, software, and knowledge. NASA's Astrophysics Division plans to host large datasets from its science missions in the cloud, and to provide cloud-based analysis capabilities for the science community. Petabytes of data from NASA’s Roman telescope, launching in 2027, will be publicly available in this way. This session will feature a panel of speakers to discuss how the Astrophysics Division is working with others within NASA and in the science community to facilitate data sharing, and to ensure that development of robust reusable open-source software and other products is appropriately funded, acknowledged, and rewarded.

• Time Domain Insights from the Roman Space Telescope

  (Wednesday, January 15, 2:00 p.m.-3:30 p.m. ET)

  The Nancy Grace Roman Space Telescope, scheduled for launch by May 2027, is poised to revolutionize time-domain astrophysics (TDA). A cornerstone of its mission is the High-Latitude Time Domain Survey (HLTDS), aimed at observing Type Ia supernovae (SNe Ia) for cosmological measurements. Beyond SNe Ia, Roman will explore a broad range of phenomena including other supernova types, tidal disruption events (TDEs), and active galactic nuclei (AGN), as highlighted by numerous submitted white papers. Closer to home there are also studies of Solar System objects and stellar variables, and the early low latitude survey. Three Project Infrastructure Teams (PITs) and teams at the Science Operations Center (SOC) and Science Support Center (SSC), along with a Wide-Field Science (WFS) team, are developing the necessary infrastructure to support Roman’s TDA capabilities. To bring the time domain aspects of these different groups together we recently formed the working group STRIDE (Strategic Time-domain Research and Infrastructure Development for Roman Exploration). Through this session we would like to introduce the group to AAS members, seek more diverse participation, as well as feedback on collaborative and complementary possibilities. Session Objectives: - Showcase Innovative/proposed Capabilities: Highlight the unique features and products of the Roman Telescope's rapid response, supernova detection, and time domain analysis systems based on simulated data. - Collaborative Opportunities: Foster collaboration among researchers by discussing data sharing, joint projects, and synergistic efforts on topics like PSF-matching, image-differencing, template construction, source detection, catalog matching, and forced photometry. - Scientific Breakthroughs: Present advancements and potential discoveries that will be enabled by the Roman Telescope, emphasizing its future impact on the field of astrophysics. - Future Directions: Explore future research directions and potential enhancements to maximize the scientific yield of the Roman Telescope. Proposed Structure: Introduction and Overview (15 minutes): Brief introduction to the Roman Space Telescope and its mission. Overview of the STRIDE group and its significance in time-domain studies. Presentations by members of associated groups (40 minutes): # RAPID (Roman Alerts Promptly from Image Differencing) PIT: - Presentation on the latest rapid response capabilities and plans. - Case studies and possible gaps. # Supernova PIT: - Supernova detection capabilities and current challenges. # High-Latitude Time Domain Survey (HLTDS) and Wide-Field Science (WFS): - Plans and bottlenecks in connection with the HLTDS and WFS # Low latitude, and Solar System science: - Time domain aspects of Galactic and Solar System science. Panel Discussion and Q&A (25 minutes): - Panel consisting of the speakers above. - Open floor for questions from the audience. Future Directions and Closing Remarks (10 minutes): - Insights into future developments and enhancements for the Roman Telescope and STRIDE initiatives. - Summary of key takeaways and closing remarks. Target Audience: - Astrophysicists and astronomers interested in all aspects of time-domain events. - Researchers focusing on rapid response mechanismsand related methodology. - Undergrads, Graduate students and early-career scientists looking to collaborate on Roman Telescope projects. Expected Outcomes: - Increased awareness and understanding of the Roman Telescope’s time-domain analysis capabilities and the STRIDE group's initiatives. - Enhanced collaboration and data sharing among the astrophysics community. - Inspiration for new research projects and proposals utilizing and advancing Roman Telescope methodology. - Valuable feedback from the community to guide future developments and improvements. Supporting Materials: - Handouts and brochures with detailed information about the Roman Telescope and the STRIDE group. - Contact information for key researchers and collaboration opportunities.

 

Oral Session Talks

• The Roman View of Gravitational Strong Lenses - B. Wedig (WUSL) et al.

  (Tuesday, January 14, 11:20–11:30 a.m. ET)

  Images of galaxy-galaxy strong gravitational lenses can constrain dark matter models and the Lambda Cold Dark Matter cosmological paradigm at sub-galactic scales, but currently, there is a dearth of high-SNR and high-angular resolution photometry of these rare systems. The Nancy Grace Roman Space Telescope (hereafter, Roman), scheduled for launch in late 2026, will play a crucial role in strong lensing science in conjunction with upcoming wide-field surveys. Roman is uniquely suited to characterizing dark matter substructure in strong lenses with its high, diffraction-limited angular resolution of 0.11 arcsec. We present a yield simulation of strong lenses detectable in Roman's planned High Latitude Wide Area Survey (HLWAS). We simulate a population of galaxy-galaxy strong lenses across cosmic time with Cold Dark Matter subhalo populations, select those detectable in the HLWAS, and generate simulated images of them accounting for realistic Wide Field Instrument detector effects. We predict around 37,000 detectable strong lenses in the HLWAS, where about 3500 will have sufficient signal-to-noise to be amenable to substructure characterization. We investigate the effect of the variation of the PSF across Roman's 0.281 deg$^2$ field of view on detecting a low-mass suppression of the subhalo mass function and single subhalos. Our simulation products are available to support future strong lens science with Roman, such as training neural networks and validating dark matter substructure analysis pipelines.

• Modeling Asteroseismic Yields of the Roman Galactic Bulge Time Domain Survey - T. Weiss (CSULB) et al.

  (Tuesday, January 14, 2:50–3:00 p.m. ET)

  In addition to its core cosmology and exoplanet science goals, the Nancy Grace Roman Space Telescope's cadence and precision in the infrared will enable asteroseismology of red giant branch stars in the Galactic bulge for the first time. Asteroseismology has proven to be revolutionary in the fields of stellar physics and Galactic archaeology thanks to its precise ages, which in the context of the bulge could contribute meaningfully to the debate regarding a young stellar population in the bulge. Here, we describe expected yields for the upcoming Galactic Bulge Time-Domain Survey, which will image the bulge over the course of the nominal five-year mission. A nominal 15-minute cadence survey yields ~300k detections in total, ~200k of which are bulge stars. We investigate the effects on the asteroseismic yields from the assumed survey strategy, noise properties, extinction choices, and assumed bulge stellar population. We find that cadence significantly impacts the yields, as does varying Roman's noise properties from the literature. By comparison, field placement and extinction choice is less important. By varying the fraction of the young-to-old bulge stars, we find that the asteroseismic yield is sensitive to the age distribution of the bulge at the 10% level, which indicates that even the asteroseismology yields themselves may place constraints on the bulge age distribution. The resulting asteroseismic ages also promise to enable tests of planet formation and evolution when combined with Roman’s expected microlensing planet yields.

• Surrounded by Rogues: Characterizing the Mass Function of Free-floating Planets with the Nancy Grace Roman Space Telescope - W. DeRocco (U Maryland)

  (Tuesday, January 14, 3:00–3:10 p.m. ET)

  During the chaotic early stages of system formation, gravitational scattering is expected to efficiently eject a large number of rocky bodies over a wide range of masses. In the terrestrial-mass range, these ejecta constitute "free-floating planets" (FFPs) and are expected to outnumber their bound counterparts. Despite the large abundance, FFPs are a difficult target for observation, with the only existing observational technique sensitive to these objects being gravitational microlensing. The launch of the Nancy Grace Roman Space Telescope in 2026 will usher in a new era for microlensing surveys, allowing the detection of up to several hundreds of FFPs. In this talk, I will show how constraints on the FFP mass function from these detections will provide interesting insights into the processes governing the birth of planetary systems.

• Validating Injected SNe Ia in the Roman OpenUniverse Time-Domain Survey Simulations - L. Aldoroty (Duke U) et al.

  (Tuesday, January 14, 3:20–3:30 p.m. ET)

  NASA’s Nancy Grace Roman Space Telescope (Roman) will provide an opportunity to study dark energy with unprecedented precision using several probes. Type Ia Supernovae are a key part of dark energy studies; as standardizable candles, they are used to construct the cosmological distance ladder. However, there are only approximately 20 SNe Ia with sufficiently well-sampled light curves above z > 1. Roman will change the landscape of SN Ia-driven dark energy studies by discovering enough SNe Ia at z > 1 to render statistical uncertainties insignificant. In order to make the best use of these observations, photometric measurements should be repeatable and precise between images. Roman’s expected photometric precision is <1, and a factor of 10 better than HST. We present our difference imaging analysis pipeline and initial photometric results from SNe Ia in the OpenUniverse simulations, using the Saccadic Fast Fourier Transform method (Hu et al. 2022).

• Public Outreach via Video Games: NASA’s Roman Space Observer - P. Sooy (NASA GSFC) et al.

  (Wednesday, January 15, 10:00–10:10 a.m. ET)

  The Nancy Grace Roman Space Telescope is a future NASA infrared observatory designed to explore essential questions in astrophysics, cosmology (the growth of structure and expansion history of the Universe), and exoplanets. Roman’s primary mirror is 2.4 meters in diameter (7.9 feet), the same size as the Hubble Space Telescope's primary mirror. Roman’s telescope and Wide Field Instrument are designed to provide excellent optical performance over an enormous field of view, which together with its 18 state-of-the-art detectors will provide sharp images over an area at least 100 times larger than Hubble. Pushing the bounds of humanity’s understanding of the cosmos, Roman is an ambitious and advanced mission. But, in the world of public outreach and engagement, the American public is not always aware of upcoming NASA missions. As Roman is being built and prepared for launch as NASA’s next flagship astrophysics mission, the “Roman Space Observer” video game has been a creative, eye-catching, and non-traditional tool to build public knowledge of and name recognition for the Roman mission. Created over a 10 month period, Roman Space Observer is an homage to retro arcade style video games, highlighting how after launching, Roman will image or ‘capture’ galaxies, exoplanets, supernova, and even the James Webb Space Telescope. The more cosmic objects you capture, the more points you get, and the high score wins. Best of all, no quarters are required to play. First rolled out in-person to the public at the American Astronomical Society (AAS) summer meeting in Pasadena, CA, in June 2022, the Roman Space Observer has been the anchor of Roman outreach events and exhibits ever since. With over 10,000 players so far, this game is tremendously successful in drawing in passersby, breaking the ice about Roman, and through gamifying a complex science mission, teaching the public about the Roman Space Telescope in an engaging way.

• Roman’s Tactile Display of the Lobster Nebula: The Story of Embedding Science in the Tactile - R. Beaton (STScI) et al.

  (Wednesday, January 15, 10:50–11:00 a.m. ET)

  One mission of the Space Telescope Science Institute (STScI) is to make astronomical information accessible to all. STScI's Office of Public Outreach works with science and data experts to create engaging and accurate experiences utilizing astronomical data. As part of this experience, STScI created a prototype Roman tactile exhibit featuring astronomical images to engage visitors through touch and sight. This opens the doors of the universe to a wider audience and also provides additional avenues for everyone to better understand our work. STScI's Roman Telescope Branch supported OPO in developing this new Roman tactile exhibit. The exhibit is intended to be fully accessible for people with and without visual impairments, particularly those without a background in astronomy. By partnering those with science expertise with exhibit designers as well as members and organizations in the blind and visually impaired community, STScI is exploring new ways to effectively communicate complicated science. With Roman tactiles, the team aims to explore new stories around survey science and highlight Roman’s expanded field-of-view, which has Hubble-like resolution in the near-infrared. Showcasing large surveys while simultaneously highlighting smaller, detailed regions are two complexities we are exploring with this prototype exhibit that employs tactile, audio, and LED technologies. The first Roman tactile utilizes an color image of the Lobster Nebula (NGC6357) from the DECam instrument on the Blanco 4-meter telescope at the Cerro-Tololo International Observatory. This image combines the broadband g and i filters with a narrow-band filter (N662) spanning the H-alpha and [NII] spectral figures to vividly highlight the complexity of the gaseous emission in this star forming region. However, the light of the gas is only part of the story and we use archival Gaia parallaxes and Fabry-Perot imaging to infer the line-of-sight distribution of the astronomical objects in the image. This presentation will describe the process of embedding science into the tactile. The Nancy Grace Roman Space Telescope is managed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, with participation by NASA's Jet Propulsion Laboratory and Caltech/IPAC in Southern California, the Space Telescope Science Institute in Baltimore, and a science team comprising scientists from various research institutions. The primary industrial partners are BAE Systems, Inc. in Boulder, Colorado; L3Harris Technologies in Rochester, New York; and Teledyne Scientific & Imaging in Thousand Oaks, California.

• Synthetic survey catalogs for the Galactic Roman Infrared Plane Survey (GRIPS) using py-ananke - A. Thob, R. Sanderson (U. Penn)

  (Thursday, January 16, 10:50–11:00 a.m. ET)

  With the imminent launch of the Nancy Grace Roman Space Telescope, our exploration of the crowded and highly obscured disc plane of our galaxy is set to reach unprecedented depths, thanks to the recent decision to define a survey of the Galactic plane with Roman. We use the py-ananke pipeline to create a suite of synthetic surveys emulating such a Galactic Roman Infrared Plane Survey (GRIPS) incorporating models of both dust extinction and observational uncertainties. We generate the surveys from the Milky Way-like simulated galaxies in the Latte suite of high-resolution FIRE cosmological simulations. We place the solar viewpoint at varied positions within each simulated galaxy to yield distinct surveys that mirror the proposed footprint of GRIPS, which encompasses the inner Galactic plane (|b| < 3° and |l| < 60°) with additional coverage in the bulge (|b| < 10°, |l| < 10°). We provide photometry in the planned F106, F158, and F213 filters of the Roman Wide Field Instrument as well as proper motions based on a proposed survey cadence. We anticipate that these synthetic surveys, which are public to the community, will serve as a robust testbed for survey planning and the refinement of analysis and data reduction pipelines for GRIPS. We discuss salient features of the surveys, including their similarities and differences from the known features of the Milky Way, and outline the available tools for accessing them.

• 3d scene reconstruction of Roman slitless spectra for host-galaxy subtraction - T. Astraatmadja (STScI) et al.

  (Thursday, January 16, 10:30–10:40 a.m. ET)

  The Nancy Grace Roman Space Telescope will carry out a wide-field imaging and slitless spectroscopic survey of Type Ia Supernovae as part of its primary goals to improve our understanding of dark energy. Proposed SN Ia surveys will be carried out using Roman's Wide Field Instrument (WFI), consisting of seven filters covering 7500—20000 Å as well as slitless prism and grism for spectroscopy. Crucial to this endeavor is obtaining supernova spectra uncontaminated by light from their host galaxies. However, obtaining such spectra is made more difficult by the inherent problem in wide-field slitless spectroscopic surveys: the blending of spectra of close objects. The spectrum of a supernova will blend with the host galaxy, even from regions distant from the supernova on the sky. Accurate removal of the host galaxy spectrum to obtain a clean, SN-only spectrum improves the accuracy of SNe luminosity distances and intrinsic brightness, thus providing a more accurate determination of the dark energy parameters. We address this problem by developing an algorithm that makes use of the spectroscopic observations of the host galaxy at all available observatory roll angles to reconstruct a three-dimensional (3d; 2d spatial, 1d spectral) representation of the underlying host galaxy—called the "scene"—that accurately matches the 2d slitless spectrum of the host galaxy when projected to an arbitrary rotation angle. The projection of the reconstructed scene can be subtracted from an observation of a supernova to remove the contamination from the underlying host. Using simulated Roman data, we show that our method has extremely small systematic errors and significantly less random noise than if we subtracted a single perfectly aligned spectrum of the host obtained before or after the supernova was visible.

• Preparing for a New Era of Transiting Exoplanet Atmosphere Studies with Roman - Y. Chai (JHU) et al.

  (Thursday, January 16, 2:00–2:10 p.m. ET)

  NASA's upcoming flagship mission, the Nancy Grace Roman Space Telescope (Roman), slated for launch by the end of 2026, promises to revolutionise our understanding of exoplanets. Among its key science initiatives is the Galactic Bulge Time Domain Survey (GBTDS), which is projected to detect around 100,000 transiting exoplanets—increasing the number of known planets by over an order of magnitude. This wealth of data will be instrumental for conducting demographic studies, offering a comprehensive view of the diverse properties of transiting exoplanets. Roman will also provide invaluable insights into exoplanet atmospheres via multi-band observations from primary transits, secondary eclipses, and phase curves. These capabilities will allow Roman to identify large-scale atmospheric trends across different exoplanet populations, advancing our knowledge of how atmospheric properties vary with planetary and host star properties. The extent to which Roman will be capable of facilitating exoplanet atmosphere science, however, may depend on survey design choices, such as photometric filters and observing cadence, that can potentially be tweaked pre-launch to maximise the breadth of science coming out of the survey. We present our efforts to investigate how these design choices will impact this exciting science case through end-to-end simulations of realistic input model atmospheric signals and their recovery using simulated Roman data.

• Multi-Star Wavefront Control at the Occulting Mask Coronagraph Testbed for the Roman Coronagraph Instrument - D. Marx (JPL) et al.

  (Thursday, January 16, 2:00–2:10 p.m. ET)

  A majority of Sun-like stars have a stellar companion that adds unwanted noise into the field of view for any high-contrast imaging instrument. Enabling binary imaging can improve the efficiency of coronagraphic instruments by increasing the number of bright, nearby stars in the pool of available science targets. This includes both of the Alpha Centauri A and B stars, which would become the top science target for direct imaging if companion leakage can be suppressed. Multi-Star Wavefront Control (MSWC) is a technique that eliminates stellar leakage from both stellar components, thereby enabling the direct imaging of exoplanets in many binary star systems.
  The coronagraph instrument onboard the Roman Space Telescope includes a contributed MSWC mask that consists of a shaped pupil mask identical to the mask used for the Wide-Field of View mode with the addition of a set of regularly spaced dots that serve as a mild diffraction grating. To enable the adoption of an enhanced wavefront control mode such as MSWC by the Roman coronagraph, we present a series of technology demonstration experiments designed to mature MSWC for the Roman coronagraph instrument. The occulting mask coronagraph (OMC) testbed in JPL’s High Contrast Imaging Testbed (HCIT) has a layout similar to the Roman Space Telescope coronagraph instrument. OMC is configured with a binary imaging mode with a MSWC mask with the same design as the contributed mask for the Roman coronagraph. Our testbed results are the first demonstrations of this technique using the recently installed full binary source. We present the latest experimental results for MSWC obtained from two vacuum test campaigns at the OMC testbed. This includes showcasing star light suppression in the Super-Nyquist regime for the 3rd diffraction order, achieving contrast levels that align with potential observations of Alpha Centauri in Band 3d (center wavelength 754nm). To date, we have demonstrated suppression of better than 5e-9 contrast in the Super-Nyquist regime using multiple diffraction orders (enabling a range of star separations ranging from 80-140 L/D. Our current test campaign using MSWC in the testbed with a binary star source aims to reach contrast levels consistent with the recent TVAC demonstrations for the Roman coronagraph instrument.

 

iPoster-Plus Sessions

• The Hourglass Simulation: A Catalog for the Roman High-Latitude Time-Domain Core Community Survey - B. Rose (Baylor U.) et al.

  (Monday, January 13, 5:30–6:30 p.m. ET)

  We present a simulation of the time-domain catalog for the Nancy Grace Roman Space Telescope's High-Latitude Time-Domain Core Community Survey. This simulation, called the Hourglass simulation, uses the most up-to-date spectral energy distribution models and rate measurements for ten extra-galactic time-domain sources in addition to a fixed luminosity source. We simulate these models through the current baseline Roman survey: four filters per tier, a five day cadence, over two years, a wide tier of 19 deg² and a deep tier of 4.2 deg², with ~20% of those areas also covered with prism observations. We find that a general time-domain catalog, assuming a S/N at max of >5, would have approximately 25,000 Type Ia supernovae, 70,000 core-collapse supernovae, over 70 super-luminous supernovae, ~40 tidal disruption events, 5 kilonovae, and possibly the first confirmed detection of pair-instability supernovae. Hourglass is a useful data set to train machine learning classification algorithms. Additionally, we present the first examples of non-Type Ia supernovae spectral-time series data from Roman's prism.

• The Astronomer's Proposal Tool for the Roman Space Telescope - M. Mutchler (STScI) et al.

  (Tuesday, January 14, 9:00–10:00 a.m. ET)

  The Astronomer's Proposal Tool (APT) is familiar to scientists who design and submit General Observer (GO) proposals for Hubble and JWST. APT now also allows for the design of observing proposals for the Wide Field Instrument (WFI) of the Nancy Grace Roman Space Telescope. Roman has a planned launch in late 2026, with a 5-year primary mission and a possible 5-year extension. The majority of the first five years will be dedicated to Core Community Surveys (CCS), which are being defined by a community-led process. General Investigator (GI) observations will also be solicited via calls for proposals, and peer-reviewed, to complete the science program. Roman APT includes a new hierarchy for designing large surveys, which Roman can conduct very efficiently with fast slews and a field-of-view which is 200 times bigger than Hubble's infrared camera. It also includes tools for designing mosaics and large region targets, and on-sky visualizations in Aladin. Demonstration programs are available in the APT menu. The Roman APT Users Guide (RAUG) is available in the Roman Documentation System (RDox), and questions or feedback can be sent to the Roman helpdesk portal at STScI.

• Exploring Extragalactic Proper Motion with the Roman Space Telescope - P. LaDuca (Brown U.) et al.

  (Tuesday, January 14, 5:30–6:30 p.m. ET)

  The combination of the Nancy Grace Roman Space Telescope’s (Roman) high angular resolution and large field of view presents an exciting opportunity for conducting previously unachievable measurements of extragalactic proper motions (PM). We investigate Roman’s ability to make these precise PM measurements and use them to add a new constraint to the Hubble constant. We create accurate simulations of extragalactic PM including the peculiar velocities of galaxies and the correlated observer-induced signals secular parallax and secular aberration drift. We inject these PMs into the recent OpenUniverse 2024 simulations of the High Latitude Wide Area Survey (WAS) to simulate a representative region of the survey following a mock observation sequence. This results in a simulated region with multiple overlapping observations spanning the duration of the WAS. We use Source Extractor to take astrometric measurements of each galaxy in our simulated region and linearly fit each PM. We use the single image astrometric precision as well as the average PM uncertainty of our simulation to propagate the error to correlated measurements of PM given the full survey. We compare our estimated precisions to the threshold precisions required to discern the different components of extragalactic PM, ~5 $\mu$as yr$^{-1}$ to measure secular aberration drift and ~0.12 $\mu$as yr$^{-1}$ for secular parallax at redshift z = 0.15. We assess the potential for Roman to study correlated extragalactic PM within the WAS and estimate the error associated with measurements of the Hubble constant using extragalactic PM.

• A Parametric Approach to Supernova Flux Recovery in Host Galaxies Using ngmix and Simulated Roman Images - Q. Cheng, D. Scolnic (Duke U.)

  (Tuesday, January 14, 5:30–6:30 p.m. ET)

  Precise recovery of supernova (SN) flux is essential for accurate cosmological measurements, yet the presence of host galaxy light often complicates this process. Traditional image subtraction techniques aim to isolate transient sources like SNe by subtracting reference images of the host galaxy from observations containing both the galaxy and the SN. While effective, these methods can be computationally intensive and may suffer from residual artifacts due to imperfect subtractions. To address these challenges, we leverage a parametric model commonly used in weak gravitational lensing analyses—to model host galaxies using a small set of parametric parameters. By representing galaxies with just six parameters, we significantly reduce the computational complexity compared to pixel-based modeling methods. We combine this parametric galaxy model with a point-source model for the SN, enabling a joint fit to the SN+host system. We apply this approach to simulated images from the Nancy Grace Roman Space Telescope, demonstrating that our method achieves more efficient SN flux recovery than standard image differencing techniques. Although our current model assumes static parameters, we plan to incorporate time-varying parameters for the SN in future work, allowing for time-series modeling of the evolving SN+host system. This advancement is expected to further reduce computational costs and enhance model accuracy.

• Unveiling the early universe with future Roman Ultra Deep Field observations - A. Koekemoer (STScI)

  (Tuesday, January 14, 5:30–6:30 p.m. ET)

  The Nancy Grace Roman Space Telescope, planned for launch later this decade, offers Hubble-quality imaging over a field of view about two orders of magnitude wider than that of HST or JWST. The Wide Field Instrument (WFI) on Roman has an instantaneous field of view of ~1000 square arcminutes, with higher sensitivity than HST over wavelengths from the optical regime up to about 2 microns. Among the new areas of observational discovery space that could be opened up by Roman is the potential for carrying out Roman Ultra Deep Field observations, reaching HUDF-quality depths up to about 30th magnitude, over degree-scale areas. This would greatly increase the discovery space for samples of high-redshift galaxies and AGN in the epoch of reionization, vastly increasing the sample sizes of these rare sources compared to previous HST results, and providing excellent complementarity with the latest JWST surveys. Moreover, targeting one or more Euclid and Rubin deep fields with Roman Ultra Deep Field observations would enable additional synergies in time-domain science and multiband imaging, all of which are crucial in expanding the discovery space of rare populations of sources in the early universe, and understanding their formation and subsequent evolution.

• Training Models of Type Ia Supernovae for the Next Generation of Cosmology Surveys - K. Anumba (Duke U.) et al.

  (Tuesday, January 14, 5:30–6:30 p.m. ET)

  In the next few years, a new generation of supernova surveys will begin, including the Legacy Survey of Space and Time (LSST) and the Nancy Grace Roman Space Telescope surveys. These surveys will help discover up to a million supernovae, orders of magnitude beyond what has been discovered so far. To use Type Ia Supernovae (SNe Ia) to constrain cosmological parameters like the equation-of-state of dark energy, one must establish a spectro-photometric model of the supernova explosion time series. The accuracy of the model itself may be one of the limiting systematic uncertainties of any cosmological inference. Here, we use the OpenUniverse simulations of the LSST and Roman survey to train a light-curve model. In this work, we show the accuracy and precision of this model over the range of wavelengths that these surveys will probe, from the optical to the near-infrared. We present a first look at how changing certain parts of the observing strategy of these surveys can change the precision of the trained models. Finally, we explain how to reproduce this work and use our trained models in forecasting the cosmological constraints of this next generation of surveys.

• The First Measurements of σ₈ with Type Ia Supernovae - J. Glaze (Baylor U.) et al.

  (Tuesday, January 14, 5:30–6:30 p.m. ET)

  Studying Type Ia supernovae (SN Ia) allows us to measure cosmological parameters including dark matter and dark energy. Currently, these studies have focused on two cosmological properties: matter and dark energy densities. Our goal is to extend SNe Ia cosmology by adding a third parameter, σ8, which describes the clustering of matter. For this analysis, I am fitting σ8 (clustering), ΩM (matter density), and the intrinsic variability of SNe Ia. We use simulations from the combined Dark Energy Survey, DESC DC2, and Roman work to determine magnifications for likely SNe discovered as part of the Roman Space Telescope Time Domain survey. The Roman Space Telescope is NASA’s next flagship mission and will produce more data than all previous SN Ia surveys combined. Also, it will give us the opportunity to go beyond our linear statistics and analyze our Universe in greater detail than ever. This research will allow us to add a third cosmological parameter for future SNe Ia analysis and the continued study of the early universe.

• Characterizing Intra-Pixel Effects in the Roman Space Telescope Detectors with the Talbot Illuminator - R. Yete (UNC Chapel Hill) et al.

  (Wednesday, January 15, 9:00–10:00 a.m. ET)

  The Nancy Grace Roman Space Telescope is NASA’s next flagship astrophysics mission, aiming to study the structure and evolution of the universe and exoplanets. One key goal is to conduct a large, high-precision near-infrared survey of the sky. This will be done with the Wide-Field Instrument, which consists of a focal plane of 18 H4RG-10 infrared detectors. Each detector is a grid of 4096 x 4096 pixels forming an image. Understanding how flux measurements are impacted by the location within a pixel where each photon is detected is critical for producing accurate measurements from the observatory. This study utilizes a novel experimental setup from the NASA Goddard Detector Characterization Laboratory, called the Talbot Illuminator, to examine intra-pixel trends on a detector with precise projections of a fine grid of spots. We applied data processing to calibrate images, extract individual spots, and measure their characteristics as their positions were shifted across the pixels. First, we mitigated noise from the detector’s readout electronics using the Simple Improved Reference Subtraction Algorithm. Then, we corrected for any default background signal from the detector. Next, we extracted individual spots by detecting their centroids and measuring properties related to their location, size, and flux. Finally, we implemented a nearest neighbors algorithm to match spots between exposures based on horizontal and vertical shifts in the Talbot Illuminator setup. Our results show that there are trends between the position of a spot centroid within a pixel and properties of its detected brightness and shape. We will further examine these trends to fully characterize them and understand how they can impact science observations in weak gravitational lensing, micro-lensing, and astrometry. The processes used to extract and analyze the spots can also be used for future Talbot Illuminator investigations. Ultimately, the information gained from this setup will help ensure accuracy for a wide variety of science from the Roman Space Telescope.

• Snowballs in Roman Space Telescope flight detectors - A. Cillis (NASA GSFC) et al.

  (Wednesday, January 15, 9:00–10:00 a.m. ET)

  Snowballs are transient events observed in HgCdTe detectors. They occur when the charge of a few pixels suddenly increases. They appear between consecutive detector reads, after which the affected pixels return to normal behavior. Several authors have noticed the appearance of snowball events in HgCdTe photodiode arrays. These features were observed, for example, in the Wide Field Camera 3 of the Hubble Space Telescope and in the NIRSpec and NIRCam instruments of the James Webb Space Telescope. In all cases, they had a low rate of occurrence, but it was challenging to present a clear picture of what may be the source of the snowball's events. Several hypotheses have been proposed about their origin, from the decay of radioactive contaminants to cosmic rays. We searched for snowball events in HgCdTe Wide Field Instrument (WFI) detectors on the Roman Space Telescope (RST). RST is a NASA observatory designed to perform wide-field imaging and spectroscopic surveys of the near-infrared sky. One of the WFI detector requirements is that materials used in the detectors shall not cause detectable high-energy particle impingement effects, such as snowballs, at a rate greater than one event/hour. To verify this requirement, we analyzed data sets under dark stable conditions acquired during all tests performed on RST flight detectors. The data was collected at NASA/GSFC and BAE Systems, Inc. (former Ball Aerospace). Only events circular in shape, where the charge collected was larger or equal to 10^5 electrons, and the snowball size was larger than 9 pixels, were counted as a "snowball." As a result of our search, we found several snowballs were repeaters, falling in the same location as a previous snowball. However, the number of snowballs repeating at the same localization decreased significantly over time. We present here the results of our work.

• The Science Operation Center of the Roman Space Telescope - D. Fadda (STScI) et al.

  (Wednesday, January 15, 9:00–10:00 a.m. ET)

  The Nancy Grace Roman Space Telescope is NASA’s next flagship astrophysics mission with a launch readiness date in October 2026 and a commitment date no later than May 2027. The observatory is equipped with the Wide Field Instrument (WFI), which provides HST-like spatial resolution over a 0.28 deg² field of view, featuring 8 imaging filters with spectral coverage between 0.48 and 2.3 microns and wide-field slitless spectroscopy capability via a grism and prism. The observatory will also have a Coronagraph technology demonstration designed to deliver high-contrast direct observations of Jupiter-mass planets around Sun-like stars. The Science Operation Center (SOC) at the Space Telescope Institute in Baltimore, MD, is in charge of planning, scheduling, low-level data processing, and archiving of all the observations. Moreover, it will provide high-level data processing for the WFI imaging mode and a cloud-based science platform for the community, the latter of which will host a suite of simulation tools that will be useful when preparing for the upcoming call for proposals. Here, we present an overview of the SOC and highlight recent news, updates, and accomplishments.

• The Nancy Grace Roman Space Telescope Wide Field Instrument Bright Star Saturation Test - D. Louie (NASA GSFC) et al.

  (Wednesday, January 15, 9:00–10:00 a.m. ET)

  The Wide Field Instrument (WFI) is the primary science instrument for the Nancy Grace Roman Space Telescope (Roman), NASA’s next Astrophysics Flagship mission. The WFI focal plane array is comprised of 18 Teledyne H4RG-10 Sensor Chip Assemblies (SCAs), which together produce a field of view ~100 times that of Hubble’s WFC3 IR camera, while offering better sensitivity and similar spatial resolution. Roman will conduct 3 Core Community Surveys (CCSs) to investigate outstanding questions regarding the expansion history of the universe and growth of structure, as well as exoplanet demographics. Additional surveys will also be pursued through a General Astrophysics program. During WFI’s second Thermal Vacuum test campaign (TVAC2) in Spring 2024, we conducted a test program to examine the effects of observing bright stars during Roman’s CCSs. The Galactic Bulge Time Domain Survey (GBTDS) field is expected to contain ~1500 stars brighter than 10^th mag and ~40 stars brighter than 7^th mag. The High Latitude Wide Area Survey (HLWAS) will include sources as bright as 3^rd or 4^th mag. These stars will go into deep saturation in typical exposures. Our Saturated Star Test program simulated 9 stellar PSFs ranging from approximately 4th to 18th mag at 9 well separated locations in a 3 x 3 grid on two SCAs in the focal plane. We collected data for typical exposure sequences planned for the GBTDS survey to quantify and characterize the effects of saturation. We also performed sequences of dark exposures after illumination to measure persistence. Here, we present the details of the test program and our initial analysis of the saturated PSF data and highlight our key findings regarding saturation and persistence.

• Ground-based Calibration of the Roman Space Telescope Wide Field Instrument - R. Beaton (STScI) et al.

  (Wednesday, January 15, 9:00–10:00 a.m. ET)

  The Nancy Grace Roman Space Telescope (Roman) will be NASA Astrophysics' first petabyte-scale mission, requiring stringent calibration to meet its ambitious science objectives. The Wide Field Instrument (WFI) on Roman, comprising 18 Teledyne H4RG-10 detectors, offers a 0.11' pixel scale across a 0.28-square-degree field of view. To address the demanding calibration requirements, an innovative internal calibration system, the Simplified Relative Calibration System (sRCS), has been developed. In preparation for Roman’s launch in late 2026, ground-test data have been collected during a series of WFI testing campaigns. These data are being used to generate the initial calibration reference products for use once the telescope is in orbit. This presentation provides a status update on the ongoing characterization of the WFI instrument and discusses the implications for in-orbit calibration.

• Characterization of brighter-fatter effect in a Roman detector and implications for weak lensing cosmology - J. Paine (UMBC) et al.

  (Wednesday, January 15, 9:00–10:00 a.m. ET)

  The Nancy Grace Roman Space Telescope (Roman) will conduct a High Latitude Wide Area Survey (HLWAS) in the near-infrared, with a primary aim of investigating the evolution of structure and cosmic expansion via weak gravitational lensing measurements. Weak lensing studies depend on measurements of very small distortions in galaxy shapes, placing stringent requirements on the characterization of detector effects that will systematically distort Roman images. One such effect is the brighter-fatter effect (BFE), which causes brighter sources to appear larger. Since the point spread function (PSF) of bright stars are used to correct the images of relatively faint galaxies for weak lensing measurements, the BFE must be calibrated to prevent overcorrection of galaxy shapes and thus biases in resulting cosmological parameter estimates. Roman’s primary instrument contains 18 Teledyne H4RG-10 near-infrared detectors which are known to exhibit BFE, as well as other nonlinear effects. We present the characterization of the BFE observed in a non-flight H4RG-10 by projecting a grid of bright point sources onto the detector using the Talbot Illuminator at the NASA Goddard Space Flight Center Detector Characterization Lab. We investigate how the measured BFE varies across the detector, with the source location within a pixel, and with the level of illumination. Finally, we discuss implications for the calibration of future Roman images and ensuing weak lensing analyses.

• Nancy Grace Roman Space Telescope: Mission Status and Expected Performance - J. Kruk (NASA GSFC)

  (Wednesday, January 15, 9:00–10:00 a.m. ET)

  The Nancy Grace Roman Space Telescope is an Astrophysics strategic mission designed to conduct large-area surveys of the sky at near infrared wavelengths. The observatory payload consists of a Hubble-size telescope aperture with a wide-field NIR instrument and a technology development coronagraph operating at visible wavelengths that employs state-of-the-art wavefront sensing and control. The Wide-field instrument is optimized for large area diffraction-limited NIR imaging and spectroscopic surveys. All data will be public immediately, and substantial general investigator programs will be supported. The Roman Project has just entered Phase D, meaning that all major observatory elements are complete and observatory-level integration and test has begun. Candidate observing programs for the three Core Community Surveys have been developed and are under review by the Roman TAC. We will present an overview of the mission design, estimated in-flight performance based on measured properties of the hardware, and a summary of Project status.

• Summary of the Nancy Grace Roman Space Telescope Flight Detector Performance - G. Mosby (NASA GSFC) et al.

  (Wednesday, January 15, 9:00–10:00 a.m. ET)

  The Nancy Grace Roman Space Telescope will study the dark matter content of the universe, the expansion history of the universe, and the diversity of exoplanets in the Galaxy using unprecedented wide field infrared surveys. Roman will accomplish this using a focal plane of 18 newly developed HgCdTe detectors. Roman’s detectors, the H4RG-10, are 4K x 4K format 10 micron pixel pitch devices manufactured by Teledyne Imaging Sensors. After acceptance testing at the Goddard Detector Characterization Lab, 18 flight detectors were selected for the flight focal plane. System level testing of the focal plane was completed at Goddard in 2023, after which the focal plane was integrated into the Wide Field Instrument (WFI) at BAE Systems (formerly Ball Aerospace). At the end of 2023, the WFI completed its first thermal vacuum test, providing the first instrument level performance measurements of the focal plane. In the spring of 2024, the WFI completed environmental (vibration and acoustic) testing and finished its second thermal vacuum test before being shipped back to Goddard for integration into the spacecraft assembly. We review the performance of Roman’s flight lot of detectors and early results from integration and testing.

• Characterization of Count-rate Dependent Nonlinearity in Roman Detectors and Implications for Dark Energy Measurements - A. Choi (NASA GSFC) et al.

  (Wednesday, January 15, 9:00–10:00 a.m. ET)

  The Roman Space Telescope will explore the origins of the accelerating expansion of the Universe through measurements of supernovae, weak gravitational lensing, and baryon acoustic oscillations. Achieving this requires stringent control of systematic errors, including the precise calibration of linearity for the 18 H4RG-10 detectors in Roman's Wide Field Instrument (WFI). The supernova program, in particular, demands a thorough understanding of nonlinearities, with the calibration required to be accurate to 0.3% over 4.5 decades. Studies of earlier generations of HxRG devices have identified count-rate dependent nonlinearity (CRNL) as a significant systematic affecting supernova cosmology analyses. The simplified Relative Calibration System (sRCS) was designed and built as an internal WFI subsystem to achieve our strict calibration requirements. The sRCS facilitates in-flight characterization and monitoring of CRNL by providing flatfield illumination across a range of light levels and wavelengths. Recently, Roman's WFI completed an extensive ground test campaign in a thermal vacuum environment to evaluate, characterize, and trend its performance. I will present results from recent tests and simulation efforts, including the characterization of CRNL, and outline the path forward for accurate and precise flux calibration throughout Roman's mission.

• Developing Outreach Materials for the Nancy Grace Roman Space Telescope - P. Molinari (STScI) et al.

  (Wednesday, January 15, 9:00–10:00 a.m. ET)

  As part of SASP 2024 I worked within STScI’s Office of Public Outreach to create outreach materials for the Nancy Grace Roman Space Telescope. I interviewed multiple researchers working on the Roman Infrared Nearby Galaxy Survey, a proposal aiming for time on the telescope. I used that material to write a press release, currently published on STScI and NASA’s websites. At the moment of writing this abstract, the press release has many pieces of published news coverage. While at STScI, I also worked on a social media campaign to promote already written press releases for Roman, using my knowledge of what engages the public to revitalize interest in already written material. I also wrote accessibility content, writing alt text for images designed for Roman outreach. With my work, these images will now be accessible to those who require screen readers to understand images. My time at SASP also included shadowing many meetings and proceedings in the Office of Public Outreach, learning how to engage both scientists and the public about Roman.

• Simulating Asteroseismic Detections for the Roman Galactic Bulge Time Domain Survey - N. Downing (Ohio State) et al.

  (Wednesday, January 15, 5:30–6:30 p.m. ET)

  Asteroseismology, the study of stellar oscillations, can be used to infer masses, ages, and radii for cool evolved stars. The Nancy Grace Roman Space Telescope’s Galactic Bulge Time Domain Survey (GBTDS) has the potential to detect asteroseismic signals through the densely populated galactic bulge, which could provide crucial clues about the underlying stellar populations there. We simulate asteroseismic detectability by modifying Kepler data to match nominal GBTDS observing strategies. We then consider different noise models and observing cadences at a range of magnitudes to quantify asteroseismic detectability. We find that with conservative noise models and slower cadences asteroseismic signals can be detected in bright Red Giant Branch and Clump stars, but with improved saturated star photometry and a faster cadence, we can detect even fainter Red Giant Branch and Clump stars. We also find that we can detect asteroseismic signals with just one 75 day sector of the GBTDS and with all 6 sectors the quality of detections is improved without much change in the total number of detections.

• A Content-Driven Strategy for Roman’s Science Platform: Enabling Low-Barrier Access and Collaboration - T. Desjardin (STScI) et al.

  (Thursday, January 16, 9:00–10:00 a.m. ET)

  Science platforms offer a unified user experience for discovering, exploring, accessing, and analyzing data. As astronomy enters an era of petabyte-scale data, cloud-based science platforms will become essential interfaces between researchers and observational data. In this poster, we present our efforts to develop content specifically designed to provide resources and engage the community with NASA’s next flagship astrophysics mission, the Nancy Grace Roman Space Telescope (Roman). With its wide field of view and unprecedented survey speed, Roman’s Wide Field Instrument is expected to generate an estimated 30 PB of data during its five-year primary mission. To prepare for Roman’s scientific discoveries, the Space Telescope Science Institute (Roman Science Operations Center) is developing a user-friendly science platform focused on low-barrier access and collaboration. We outline the development of simulated datasets, Jupyter tutorials, science workflows, and other tools for the cloud-based platform. These resources demonstrate the platform's capabilities, ease of use, and help prepare users for a new era in observational astronomy.

• Simulation Tools for the Roman Space Telescope - E. Han (STScI) et al.

  (Thursday, January 16, 9:00–10:00 a.m. ET)

  The Nancy Grace Roman Space Telescope (Roman), set for launch in late 2026, will be supported by a suite of simulation tools developed by the Science Operations Center (SOC) at the Space Telescope Science Institute. These tools are designed to help the astronomical community understand and optimize the capabilities of the Wide Field Instrument (WFI). The simulation tools suite ranges from simple Python notebooks to advanced, full-scale simulations of WFI observations, including instrumental effects. Key tools provide functionalities such as point-spread function modeling, high-fidelity exposure time calculations, and image simulations of complex astronomical scenes. These resources are designed to be accessible, with online interfaces and comprehensive user documentation, supporting the community's scientific preparations for Roman’s groundbreaking mission.

• Streamlining Cloud-Based Infrastructure Monitoring for the Nancy Grace Roman Space Telescope - V.K. Dubey (STScI)

  (Thursday, January 16, 9:00–10:00 a.m. ET)

  Soon, the Nancy Grace Roman Space Telescope (Roman) will be launched, relying extensively on a sophisticated cloud-based system to handle and analyze the enormous quantities of data it gathers. This system, constructed using Amazon Web Services (AWS), facilitates essential mission operations, including the Exposure Time Calculator (ETC) and Data Processing elements. The ETC operates on EC2 instances, while data processing employs Kubernetes clusters hosted within AWS Elastic Kubernetes Service (EKS). The project requires a comprehensive surveillance system allowing NASA personnel to monitor various cloud infrastructure components (such as EC2, S3, Lambda, EKS, and others) in real time. This system tracks system configurations and automatically notifies of changes in resource usage and security permissions. The goal was to convert previously static infrastructure reports into dynamic, real-time evaluations. One example is the EC2 Audit Report, which tracks instances involved in the mission's exposure time calculations and data management. Additionally, the system employs Infrastructure as Code (IaC) principles, enabling management of the entire infrastructure through version-controlled templates. A key feature of this system is its ability to automate the yearly security assessments required by NASA, particularly for high-level AWS roles. These assessments verify that only authorized personnel can access critical systems. By automating difference reports that record changes in permissions and roles, the system reduces the manual effort needed for maintaining compliance and enhances overall security. This development represents a significant step in readying the Roman mission's cloud infrastructure for launch, providing real-time insights into its status, automating security audits, and supporting the mission's long-term data processing needs.

• Automated Data Quality Monitoring of the Roman Space Telescope Wide Field Instrument - W. Schultz (STScI) et al.

  (Thursday, January 16, 9:00–10:00 a.m. ET)

  The Nancy Grace Roman Space Telescope (Roman), NASA's next flagship mission, is set to launch in late 2026. Over its five-year primary mission, Roman will conduct large-scale, community-defined surveys, including time-domain observations, producing over 17 terabytes of uncompressed science data daily. This volume of data far surpasses the total from all current NASA astrophysics missions combined. The Science Operations Center (SOC) at Space Telescope Science Institute is developing a tool to monitor the pixel-level quality of the Wide Field Instrument (WFI) data before and after automated calibration. In this poster we describe the monitoring components currently implemented and discuss future enhancements.

• Realistic Non-Parametric Modeling Of Emission Line Morphological Substructure among 1<z<3 Galaxies For Effective Roman Science using Deep Generative Learning - K. Mantha (U. Minn.) et al.

  (Thursday, January 16, 1:00–2:00 p.m. ET)

  The Roman Space Telescope’s Galaxy Redshift Survey (GRS) will survey thousands of square degrees of the sky probing for emission-line galaxies between 1<z<3. Accurately measuring the redshifts is a critical step for GRS’s success and simulated mock lightcones created by forward modeling N-body simulations with semi-analytical baryonic prescriptions have been pivotal in informing various Roman-GRS expectations. However, these mock realizations assume smooth and parametric light-profile distributions for their galaxies’ structural components, while there is ample observational evidence for the morphology being more clumpy and spatially non-homogeneous. Motivated by this, we explore the use of generative deep learning frameworks (specifically, Denoising Diffusion GANs, Conditional GANs) as a potential avenue to predict realistic H-alpha emission line maps based on input galaxy physical properties (e.g., redshift, stellar mass, effective size, etc). In this poster, we present an overview of our DL frameworks and preliminary training results on the data from UVCANDELS and mock IFU data from the Illustris-TNG simulations.

 

NASA Hyperwall Talks (NASA exhibit)

• Roman Project Overview - Dominic Benford (NASA GSFC)

  (Day/time TBD ET)

  TBD.

• Roman Wide Field Instrument: From ground tests to science - Jennie Paine (UMBC)

  (Day/time TBD ET)

  Connect the hardware to the science via some examples of recent test performance (e.g., from the Wide Field Instrument thermal vacuum testing, testing in the Detector Characterization Lab at Goddard).

• Roman Galactic Plane Survey - Bob Benjamin (UWW)

  (Day/time TBD ET)

  We will be presenting a preliminary design for the 700 hour Roman Space Telescope Galactic Plane Survey.

• Roman Coronagraph - Julien Girard (STScI)

  (Day/time TBD ET)

  Imaging giant exoplanets in reflected light for the first time and before 2030.

• Roman Core Community Survey: High Latitude Wide Area Survey - TBD (TBD)

  (Day/time TBD ET)

  Summary of High Latitude Wide Area Survey definition.

• Roman Core Community Survey: High Latitude Time Domain Survey - TBD (TBD)

  (Day/time TBD ET)

  Summary of High Latitude Time Domain Survey definition.

• Roman Core Community Survey: Galactic Bulge Time Domain Survey - TBD (TBD)

  (Day/time TBD ET)

  Summary of Galactic Bulge Time Domain Survey definition.

• Roman Coronagraph - TBD (TBD)

  (Day/time TBD ET)

  Updates on Roman Coronagraph.

• What to expect for Galaxy Evolution with Roman: Lessons from JWST - Vihang Mehta (Caltech/IPAC)

  (Day/time TBD ET)

  The Nancy Grace Roman Space Telescope is set to unravel a new chapter for galaxy evolution with spectroscopic coverage of the sky, as part of its High-Latitude Wide Area Survey. We leverage ongoing JWST programs with the NIRISS grism to provide a sneak preview of what we can expect to learn about how galaxies form and grow over cosmic time with the treasure trove of Roman near-IR grism spectroscopy.

• Cloud Science Platforms in the Era of Big Data - Thomas Dutkiewicz (STScI)

  (Day/time TBD ET)

  Observatories like TESS and Roman are rapidly pushing space-based astronomy into an era of big data. Cloud platforms will enable scientists to access and analyze data on the petabyte scale.