Submitted Abstracts
Assessing the Impact of Binary Systems on Microlensing Using SPISEA and PopSyCLE Population Simulations
By: Natasha Abrams
Type: Talk
Abstract: Gravitational microlensing provides a unique opportunity to probe the mass distribution of stars, black holes, and other objects in the Milky Way. The contribution from binary objects is often minimized in analysis of both observations and simulations despite the high percentage of binary systems and microlensing's ability to probe binaries. To simulate the population effects we added multiple systems to SPISEA, software that simulates stellar clusters. We then inject these multiples into PopSyCLE, a package that simulates Milky Way microlensing surveys. When making observational selection criteria, we find that 55% of simulated microlensing events involve a binary system. The majority of these events have photometric lightcurves that appear single (i.e. single-peaked lightcurves). This suggests that binary models should be included more frequently in event analysis. The presence of binaries will affect how we interpret microlensing results from the Nancy Grace Roman Telescope Galactic Bulge Time Domain Survey.
Co-Authors: Jessica R. Lu, Casey Y. Lam, Michael S. Medford, Matthew W. Hosek, Jr., and Sam Rose
Environmental dependence of chemical evolution probed by near-infrared spectroscopic observations of high-z clusters
By: Kota Adachi
Type: Talk
Abstract: Chemical evolution of galaxies is determined by not only past star formation activities but also gas inflow/outflow depending on the surrounding environments. We report on our near-infrared spectroscopy of member galaxies in a z=1.46 cluster with Keck/MOSFIRE to measure gas-phase metallicities. Our results show they have enhanced metallicities compared to field galaxies at similar redshift, and ones in the core region have suppressed outflows from chemical evolution model.
We conclude that the metallicity enhancement in this X-ray cluster is caused by the lack of metallicity dilution due to inefficient gas accretion in shock-heated ICM. Moreover, the outflow is also suppressed due to confinement and fallback of metal-enriched gas by dense IGM.
Roman/WFI will obtain statistically sufficient samples of gaseous properties in both field and cluster populations and enable us to test this chemical evolution scenario at cosmic noon, the era of vigorous mass assembly occurring.
Co-Authors: Tadayuki Kodama, Jose Manuel Pérez-Martínez, Tomoko Suzuki, and MAHALO team members
Initial photometric results from the RomanDESC Time-Domain Survey Simulations
By: Lauren Aldoroty
Type: Talk
Abstract: 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. We present initial photometric results from the RomanDESC simulations (Troxel et al. 2022), focusing on difference imaging using the Saccadic Fast Fourier Transform method (Hu et al. 2022) and SN Ia photometry.
Co-Authors: Lei Hu, Daniel Scolnic, Michael Troxel, and the Roman Supernova Project Infrastructure Team
Supercharging Roman exoplanet demography through a precursor survey with ESA Euclid
By: Jean-Philippe Beaulieu
Type: Talk
Abstract: We discuss how observations by ESA Euclid of the Roman Galactic Bulge Time Domain Survey (GBTDS) area could dramatically enhance the exoplanet science output of Roman. An early Euclid precursor survey of the Roman GBTDS fields, conducted 2.5 years before the start of the GBTDS, could improve the precision of Roman exoplanet mass measurements by a factor of nearly 4, as well as improve the purity of Roman TRExS transit sample. ESA is currently considering the scheduling and feasibility of such a survey. After the end of the Euclid cosmology survey, a simultaneous observational campaign by Euclid and Roman could also achieve large gains in several areas of Roman exoplanet science, including enabling direct mass measurement of free-floating planets, and even possible confirmation and mass measurements of exomoons.
Co-Authors: Matthew Penny (LSU), Etienne Bachelet (IPAC), Jean-Philippe Beaulieu (IAP), Valerio Bozza (Salerno), Sarah Casewell (Leicester), Iain McDonald (Manchester), Clément Ranc (IAP), Jason Rhodes (JPL), Maria Rosa Zapatero Osorio (CAB). [note that one of these, rather than Kerins, is likely to present the talk].
The Roman Microlensing Survey’s Confirmation or Refutation of Gas Giant Exoplanet Formation Theories
By: Alan P. Boss
Type: Poster
Abstract: The field of exoplanet research is moving from one of discovery and characterization of interesting new classes of objects to one where enough information on the thousands of exoplanets discovered to date can be used to inform population demographics across the spectrum of exoplanet and host star masses. Direct imaging and ground-based microlensing surveys excel at detecting long-period exoplanets. The microlensing survey of the Roman Space Telescope (RMS) will help complete the census by possibly discovering hundreds of long-period and free-floating exoplanets. Long-period gas giants are difficult to form by the core accretion mechanism, but the gas disk gravitational instability (GDGI) mechanism is capable of forming gas giants at distances of 10 au and beyond for AFGKM host stars. The RMS will provide convincing evidence about whether the GDGI mechanism is needed to explain exoplanet demographics.
Co-Authors: none
IMCOM: optimized image coaddition pipeline for Roman weak lensing cosmology
By: Kaili Cao
Type: Talk
Abstract: Roman will implement a devoted weak gravitational lensing program with its High Latitude Imaging Survey. Image coaddition is to combine dithered, undersampled raw exposures of HLIS into unified, oversampled images suitable for cosmological measurements. IMCOM formulates this process as a linear transformation; benefiting from knowledge about Roman point spread function, it provides control over reconstructed PSF in output images. Applying IMCOM to simulated science images, noise fields, and injected sources, we demonstrate its capability of producing exquisite sky atlas with de-amplified noise and minimal shear bias. Alternative solvers and experimental features have been developed to eliminate artifacts and further improve image quality. With a set of holistic and objective evaluation criteria, we fine-tune IMCOM configuration for best science yield. Together with other image processing efforts, IMCOM can inform survey strategy design in terms of needed exposure time and tiling pattern. We believe IMCOM is useful for coaddition purposes in general.
Co-Authors: Christopher M. Hirata, Katherine Laliotis, Masaya Yamamoto, Emily Macbeth, Michael A. Troxel
The Cosmic Optical Background with Roman: Lessons from Hubble
By: Timothy Carleton
Type: Poster
Abstract: The level of the cosmic optical background light provides a powerful test of our understanding of cosmology and galaxy evolution. If we have accounted for all astrophysical sources, the level of the optical/near-IR background light should equal that of all resolved sources. However, recent observations suggest that the level of the optical background is above that predicted by models and galaxy counts. Given its large field of view and depth, Roman can effectively study the optical background light, both in terms of its absolute level and how it varies across the sky. I will present results from the all-sky archival HST program SKYSURF, which aims at studying the optical background with HST’s archive, and showcase lessons to be learned for Roman, including detection of low-surface brightness galaxies, instrumental contributions to the background level, and the effect of cosmic variance on the optical background light.
Co-Authors: Rogier Windhorst, Rolf Jansen, Rosalia O'Brien, Isabel McIntyre, Delondrae Carter
Studying cosmology and galaxy evolution with Roman and SPHEREx
By: Yun-Ting Cheng
Type: Talk
Abstract: SPHEREx, NASA's next MIDEX mission, will launch in early 2025. With its all-sky near-infrared spectral imaging survey from 0.75-5μm, SPHEREx will address key questions on cosmological, galaxy formation, and the origin of biogenic signatures, with its low-resolution spectroscopic catalog and near-infrared spectral images. The deep photometric and spectroscopic catalog from Roman HLS complements SPHEREx, offering promising prospects to study cosmology and galaxy evolution over cosmic time. In this talk, I will first give an overview the SPHEREx mission, present a case study of probing galaxy evolution from the local universe to the epoch of reionization. Finally, I will conclude with other potential avenues of unique studies that can be achieved by the synergy between SPHEREx and the Roman dataset.
Deciphering Baryonic Feedback from tSZ Galaxy Clusters
By: Nihar Dalal
Type: Poster
Abstract: The goal of the next generation of cosmic shear surveys is to probe the matter distribution of the universe to incredible precision. In order to actually attain this level of precision on cosmological parameters, we need to use information at small scales of ~ 1 h^-1 Mpc, which requires a robust model of baryonic feedback. We use the Dark Matter + Baryon (DMB) model, a flexible halo model with several parameters to describe baryonic feedback that is well fit to a variety of different hydrodynamical simulations. Using a sample of tSZ selected galaxy clusters from ACT with masses calibrated via DES, we show that the tSZ Y-M relation can provide excellent constraints on several DMB model parameters, and thereby give us crucial information about the impact of baryonic feedback on cosmic shear. We also present Fisher forecasts of this analysis for Roman, and discuss possible synergies with CMB stage IV.
Co-Authors: Chun-Hao To, Chris Hirata
Reconstructing the Mass Function of Free-floating Planets with Roman
By: William DeRocco
Type: Talk
Abstract: 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. The only existing observational technique sensitive to these objects is gravitational microlensing. Through its Galactic Bulge Time Domain Survey, Roman will usher in a new era for microlensing surveys, allowing the detection of up to several hundreds of FFPs. In this talk, I will demonstrate that constraints on the FFP mass function from these detections will provide interesting clues into the processes governing the birth of these rogue worlds, with implications for models of planetary formation and dynamics.
Co-Authors: Peter McGill (LLNL) Scott Perkins (LLNL) Samson Johnson (JPL) Will Dawson (LLNL)
Roman-CGI: An opportunity to Survey Planetary Systems in Unprecendented Detail
By: John Debes
Type: Talk
Abstract: While the coronagraphic instrument (CGI) on Roman is primarily a technology demonstration, it holds the potential to take a massive step forward for high contrast visible imaging of planetary systems in space and pushing our understanding of planetary formation and evolution theory. I lay out three possible futures of CGI: 1) a successful observation phase that reaches the nominal mission requirements and conducts observations over 90 days, 2) a wildly successful technology demonstration that reaches the best estimated performance during just the nominal 90 day observing period, and 3) observing programs that could proceed if an extended mission or more investment in CGI came to pass. In these three scenarios direct imaging of mature planets, young planets, exozodis, and warm debris disks become possible. Thus, CGI could become a precursor science mission that advances our knowledge of nearby planetary systems and paves the way for directly imaging the next Earth.
Simulating Asteroseismic Detections for the Roman Galactic Bulge Time Domain Survey
By: Noah James Downing
Type: Poster
Abstract: Asteroseismology, or the study of stellar oscillations, can be used to infer masses, ages and radii for evolved cool stars. The Galactic Bulge Time Domain Survey (GBTDS) has the potential to detect asteroseismic signals throughout the densely populated galactic bulge, which could provide crucial clues about the underlying stellar populations there. We simulate asteroseismic detectability using the Gadfly package, which generates both synthetic theoretical power spectra and Gaussian process realizations of them. We then consider different noise models and observing strategies to quantify asteroseismic detectability. We find that the error floor for bright, saturated stars is an important consideration for asteroseismic detections. Having repeat visits to at least some fields during the 15 minute duty cycle could also have a significant impact on yields.
Co-Authors: Lead Author: Noah Downing Co-Authors: The Roman Asteroseismology Wide Field Science Team
Simulation tools for the Roman Space Telescope
By: Dario Fadda
Type: Poster
Abstract: The Nancy Grace Roman Space Telescope is currently on track to be launched in late 2026. The Science Operation Center (SOC) at the Space Telescope Science Institute is now working to support the astronomical community by developing a suite of simulation tools to optimally exploit the capabilities of the telescope when planning surveys.
We present tools to estimate the exposure time in a variety of configurations and observational settings (Pandeia) and a lightweight, quick look version to explore the feasibility of observations for the Wide Field Instrument (RIST); a tool to compute the point-spread function as a function of wavelength and position on the focal plane array (Roman WebbPSF); a tool to simulate imaging data for complex wide-area astronomical scenes (STIPS); a Python notebook to show the footprint of a pointed observation at different position angles on the sky; a galsim-based tool for simulating observations including instrumental effects (Roman I-Sim).
User documentation for these tools is available at https://roman-docs.stsci.edu/simulation-tools-handbook-home.
Co-Authors: Taylor Desjardins, Charles Lajoie, Gisella de Rosa, Rachael Beaton, Sebastian Gomez, Eunkyu Han, Andrea Bellini, Sanjib Sharma, Justin Otor, Eddie Schlafly, Javier Sanchez, John Wu, Adric Riedel, Marshall Perrin, Brian York.
Studying the Formation and Evolution of Galaxy Clusters with Roman Weak Lensing
By: Kyle Finner
Type: Talk
Abstract: Galaxy clusters are important laboratories for understanding the formation and growth of the large-scale structure. They are also the sites of the most energetic events since the big bang, when cluster-cluster collisions occur. Weak lensing is a powerful technique for identifying the substructures of galaxy clusters, which provide critical information on the formation of clusters. The Roman Space Telescope provides the ideal combination of resolution and field of view to study galaxy clusters with weak lensing. I will present the current view of galaxy clusters that are provided by the best operating ground- and space-based observatories. I will show that Roman combines the best features of these telescopes and, combined with weak lensing, will enable a deeper understanding of the distribution of dark matter in galaxy clusters. In addition, I will discuss how Roman's filter selection will be valuable for studying clusters in the z>1 regime, a redshift range that has been difficult to study in the past.
Semi-analytic bubbles - probing high redshift reionization sources with mock deep Roman surveys
By: Austen Gabrielpillai
Type: Talk
Abstract: Cosmic reionization was the last critical phase transitional of the intergalactic medium (IGM) and have significant implications on the Universe’s evolutionary history. Although recent observations of ionized bubbles surrounding high-redshift galaxies provide us isolated windows into the reionization process, the IGM’s conditions are poorly constrained due to uncertainties in the galaxy ionizing photon production rate, dN_ion/dt, and the photon escape fraction, f_esc. In this work, we conduct IGM reionization simulations between 6 < z < 10 using a 2 deg^2 semi-analytic lightcone. We calculate dN_ion/dt for our galaxy sample using the BPASS stellar population synthesis model for single and binary stars, producing mock IGM reionization maps. We also measure r_eff, n_bubbles, and cumulative distribution functions of our identified bubbles in our maps as a function of redshift. Our results emphasize that deep surveys conducted by Roman Space Telescope are necessary to fully constrain the uncertainties of cosmic reionization.
Co-Authors: James E. Rhoads, L. Y. Aaron Yung, Sangeeta Malhotra, Rachel S. Somerville
The Roman Galactic Exoplanet Survey Project Infrastructure Team
By: Bernard Scott Gaudi
Type: Talk
Abstract: One of the Roman core community surveys is the Roman Galactic Bulge Time Domain Survey (RGBTDS), which will notionally monitor ~2 sq. degrees toward the Galactic center with a cadence of ~15 minutes in a wide 1-2 micron filter over 6 seasons of 62-72 days, for a total survey duration of 372-432 days. One of the primary goals of the RGBTDS is the Roman Galactic Exoplanet Survey (RGES), which will carry out a statistical census of planetary systems in the Galaxy, from the outer habitable zone to free floating planets, including analogs to all of the planets in our Solar System with the mass of Mars or greater. I will summarize the activities of the RGES Project Infrastructure Team (RGES-PIT) over the next five years in support of this goal, focusing on ways in which the larger microlensing, exoplanet, and astronomical communities can get involved.
Co-Authors: The Roman Galactic Exoplanet Survey Project Infrastructure Team
Starburst and Quenching of Low-mass Galaxies: Preparing for Roman's Joint Data Processing
By: Yicheng Guo
Type: Talk
Abstract: Low-mass galaxies (with stellar mass less than 10^9.5 solar mass) are an extremely sensitive probe of galaxy assembly history and interaction with dark matter halos. These galaxies, however, have not been thoroughly studied beyond our local universe due to their faint brightness and small size. In this talk, I will present our work on measuring the physical properties of low-mass galaxies at z~1 using HST and JWST images and ground-based spectroscopy. First, we constrained the duration and period of episodic star formation bursts in the history of low-mass galaxies through UV and nebular emissions. Second, we used the difference between the central surface mass density of star-forming and quenched low-mass galaxies to constrain quenching mechanisms and timescale. I will then discuss the opportunities that Roman will bring to the joint analysis of low-mass galaxies, particularly through its large field-of-view and slitless spectroscopy.
Production of free-floating planets via dynamical instabilities
By: Sam Hadden
Type: Talk
Abstract: Roman’s microlensing survey will probe the populations of free-floating and wide-separation planets. Free-floating planets are generally assumed to have assembled around stars and subsequently been ejected through dynamical instabilities. We explore the production of free floating planets through dynamical instabilities using suites of N-body integrations. We show that, in the absence of giant planets, unstable planetary systems with initial orbital distances beyond ~5-10 AU will typically experience prolonged bouts of dynamical scattering that can last billions of years or more. During this phase, planets are thrown onto highly inclined and eccentric orbits without being ejected from the system. More generally, we argue that understanding the long-term dynamical evolution of unstable planetary systems at wide separations will be essential for interpreting microlensing planet detections from Roman.
Co-Authors: Yanqin Wu, Ethan Shore
Extracting the Full Cosmological Information of Roman with SimBIG
By: ChangHoon Hahn
Type: Talk
Abstract: The 3D distribution of galaxies encodes key cosmological information that can probe the growth and expansion history of the Universe. In my talk, I will present how we can leverage machine learning and simulation-based inference to go beyond current analyses and extract the full cosmological information of the next-generation galaxy surveys. In particular, I will present SimBIG, a galaxy clustering analysis framework using simulation-based inference with normalizing flows. I will show the latest results from applying SimBIG to BOSS observations to analyze the bispectrum, wavelet scattering transform, and a field-level summary— down to small, non-linear, scales. By robustly extracting additional cosmological information, SimBIG constrains $\Lambda$CDM parameters, $\Omega_b$, $h$, $n_s$, $\Omega_m$, and $\sigma_8$, that are 2.4, 1.5, 1.7, 1.2, and 2.7$\times$ tighter than standard analyses. Lastly, I will discuss how SimBIG can be extended to Roman to produce leading cosmological constraints that probe the growth and expansion history of the Universe.
NANCY: Next-generation All-sky Near-infrared Community surveY
By: Jesse Han
Type: Talk
Abstract: Roman is capable of delivering an unprecedented all-sky, high-spatial resolution, multi-epoch infrared map to the astronomical community. This imaging will not only enhance other surveys, but also facilitate completely new science. By imaging the full sky over two epochs, Roman can measure the proper motions for stars across the Milky Way, probing 100 times fainter than Gaia out to the very edge of the Galaxy. We thus propose NANCY: a completely public, all-sky survey that will create a high-value legacy dataset benefiting innumerable studies of the universe. NANCY is a pure expression of Roman's potential: it images the entire sky, at high spatial resolution, in a broad infrared bandpass. The majority of all ongoing astronomical surveys would benefit from incorporating observations of NANCY into their analyses, whether these surveys focus on nearby stars, the Milky Way, near-field cosmology, or the broader universe.
Co-Authors: 200+ co-authors, listed on https://ui.adsabs.harvard.edu/abs/2023arXiv230611784H/abstract.
A Hidden Population of Active Galactic Nuclei Can Explain the Overabundance of Highly-Luminous, $z>10$ Objects Observed by JWST
By: Sahil Hegde
Type: Talk
Abstract: JWST results have challenged theoretical models, revealing an overabundance of luminous galaxies and uncovering a large population of massive BHs at early times. Because many of these high-z “galaxies” appear extended, the possible contribution of AGNs to their total rest-UV luminosity has generally been neglected. In this work, using a semi-empirical model for assigning AGNs to galaxies, we show that galaxies hosting AGNs with low enough luminosity to remain morphologically “hidden” can provide enough luminosity to solve the overabundance problem. Constraining the extent of AGN contribution to the high-z UVLF will provide insight into SMBH seeding and co-evolution with galaxies, has implications for reionization, and will require spectroscopic surveys of a large number of sources in the near-IR. With its wide field of view, the Roman telescope is particularly well-suited for this purpose and will help to characterize the joint AGN and galaxy LF across a wide range of magnitudes.
Co-Authors: Michael M. Wyatt, Steven R. Furlanetto
The Galactic Bulge Time Domain Survey in Context with Galactic Models
By: Macy Huston
Type: Talk
Abstract: The Roman Space Telescope’s Galactic Bulge Time Domain Survey (GBTDS) will detect microlensing events and other time-domain phenomena, putting theories of Galactic science to the test, including planet formation, black hole populations, and Galactic structure. In order to optimize field selection, we use Galactic models to predict the yields of cold exoplanets with mass measurements and other phenomena. At present, Galactic models including the Besancon Model, SynthPop, and PopSyCLE do not reproduce the infrared star counts and microlensing event rates observed by VVV. In this talk, I discuss how improvements to Galactic models including the addition of the nuclear stellar disk and cluster can help resolve this issue. These improved models can be used to adjust the GBTDS survey fields to increase microlensing event yield and insight into populations of dark objects (planets, black holes, and more) in different regions of the Milky Way.
Exploring Relationship between Assembly bias and Halo properties toward Dark Emulator II
By: Keitaro Ishikawa
Type: Talk
Abstract: Galaxies are formed in dark matter halos. The spatial distribution of dark matter halos and the distribution and the number of galaxies within a dark matter halo primarily depend on halo mass. Still, it is known that they depend on halo properties other than mass, such as halo formation history (Wechsler et al. 2006). This secondary dependence is called assembly bias. Because of dramatic improvements in statistical accuracy in the upcoming galaxy surveys, ignoring assembly bias will bias cosmological parameter constraints (Miyatake et al. 2022). In this work, to construct a halo statistics emulator that also predicts assembly bias, we explore how the amplitude of the halo-halo correlation function changes as a function of halo concentration, using Dark Quest II simulation data. In this talk, I will talk about that progress and discuss the perspective of cosmological analysis using a cosmological emulator in which assembly bias is incorporated.
Co-Authors: Takahiro Nishimichi, Hironao Miyatake, Satoshi Tanaka, Tomomi Sunayama
Photometric redshifts from the Roman HLTDS -- implications for supernova cosmology and galaxy evolution science
By: Bhavin Joshi
Type: Talk
Abstract: We report results from an investigation into the expected performance of photometric redshifts (photo-z) from the Roman High Latitude Time Domain Survey (HLTDS). This study focuses on the effect of including/excluding various WFI filters on photo-z. The analysis is done using a sample of 100K galaxies with Roman WFI photometry simulated using the SNANA package. We compute photo-z for various WFI filter configurations using EAZY for redshift fitting. We show that a 4-band survey (or survey tier) offers dramatically reduced photo-z performance vs a 6 or 7-band survey. We argue that a 4-band survey will likely have to be supplemented by ground-based observations and/or additional WFI data through Roman general astrophysics programs. We also show that the bluer bands (F062 and F087) are critical to reducing catastrophic failures. These results have significant implications for type Ia supernova host galaxy redshifts and any ancillary galaxy evolution science done with HLTDS data.
Detecting Population III Stars through Tidal Disruption Events in the Era of JWST and Roman
By: Rudrani Kar Chowdhury
Type: Poster
Abstract: First generation metal free stars, known as Population III (Pop III) stars, that were formed from primordial gas shortly after Big Bang are important to understand the complex structures of the universe. However, they are extremely difficult to detect due to their short lifespan and large distance. For the first time, we propose a unique channel to detect Pop III stars by probing the emission when they are tidally disrupted by massive black holes at high redshift. We find fallback rate of disrupted Pop III stellar debris are extremely large, causing high luminosity that render them feasible for detection. Most importantly, rest-frame luminosities at z~10 peak at ultraviolet/optical wavelength that is redshifted to near-infrared band in current epoch. We find promising results of detecting a significant number Pop III TDEs with Roman. Follow up observations with JWST will lead to precise identification of Pop III stars.
Co-Authors: Janet N.Y Chang, Lixin Dai, Priyamvada Natarajan
RoSETZ: Roman Survey of the Earth Transit Zone -- a SETI-optimized survey for habitable-zone exoplanets
By: Eamonn Kerins
Type: Talk
Abstract: We propose the Roman Survey of the Earth Transit Zone (RoSETZ), a transit search for rocky planets within the habitable zones (HZs) of stars located within the Earth Transit Zone (ETZ). The ETZ holds special interest in the search for extra-terrestrial intelligence (SETI) - observers on planets within the ETZ can see Earth as a transiting planet. RoSETZ would augment the Roman Galactic Bulge Time Domain Survey (GBTDS) as an additional field located ∼5 degrees away from other GBTDS fields. RoSETZ can find hundreds of Earth-sized HZ planets around K- and M-type hosts. The angular separation of RoSETZ from other GBTDS fields also permits self-calibration of systematic uncertainties that would otherwise hamper exoplanet demographic modelling of both microlensing and transit datasets. Other science possible with RoSETZ data include studies of small solar system bodies and high resolution 3D extinction mapping.
Co-Authors: Eamonn Kerins, Supachai Awiphan, Kathryn Edmondson, Michael Garrett, Jacob Haqq-Misra, Rene Heller, Macy Huston, David Kipping, Ravi Kopparapu, Danny C. Price, Andrew Siemion, Siddhant Sharma Evan L. Sneed, Hector Socas-Navarro, Robert F. Wilson, Jason Wright. [Kerins to present]
Free-floating planet mass function from MOA-II 9-year survey and expectations for Roman
By: Naoki Koshimoto
Type: Talk
Abstract: Free-floating planets (FFPs) are planetary-mass objects without host stars, and cold FFPs can only be studied by microlensing. Johnson et al. (2020) estimated that the Roman microlensing survey would discover ~250 FFPs with masses down to that of Mars including ~60 with masses ≤ M_earth.
In this study, we analyzed all images taken over 9 years from 2006 to 2014 by the microlensing survey with the MOA-II 1.8 m telescope. We identified six FFP candidate events with tE < 0.5 days. The parameter distribution of these short events can be well modeled by a power-law mass function with ~2.2 (M/8M_earth)^alpha /dex/star with α ~ -0.96. This is the first mass function measurement down to ~M_earth.
Using this mass function, we predict that Roman will find ~1000 FFPs, including ~600 FFPs with 0.1 < M/M_earth < 1, which is much more than previously predicted by Johnson et al. (2020).
Co-Authors: Takahiro Sumi, David P. Bennett, Nicholas J. Rattenbury, Fumio Abe, Richard Barry, Aparna Bhattacharya, Ian A. Bond, Hirosane Fujii, Akihiko Fukui, Ryusei Hamada, Yuki Hirao, Stela Ishitani Silva, Yoshitaka Itow, Rintaro Kirikawa, Iona Kondo, Yutaka Matsubara, Shota Miyazaki, Yasushi Muraki, Greg Olmschenk, Clément Ranc, Yuki Satoh, Daisuke Suzuki, Mio Tomoyoshi, Paul. J. Tristram, Aikaterini Vandorou, Hibiki Yama, Kansuke Yamashita
Finding black holes with microlensing: current and future prospects
By: Casey Lam
Type: Talk
Abstract: Gravitational microlensing is the only practical way of detecting isolated stellar-mass black holes (BHs). Although isolated BHs are expected to constitute the majority of the Galactic BH population, there has only been one confirmed detection to date. Finding and characterizing the isolated BH population is important to understanding a broad range of other astrophysics, from the evolution and death of massive stars, to binary interactions, mergers, and disruptions, to providing context for the population of merging BHs found via gravitational waves. I will discuss the recent detection of an isolated BH, some of the unexpected complications that arose in its analysis, and what we have been able to learn from a sample size of 1. I will then look forward to how we can detect and characterize a population of isolated BHs with the Roman Space Telescope.
Co-Authors: Jessica Lu (UC Berkeley)
Testing planet formation with Roman
By: Eve Lee
Type: Talk
Abstract: Uniquely capable of probing low-mass planets at intermediate orbital distances, Nancy Grace Roman Space Telescope presents an exciting opportunity to test theories of planet formation in the outer reaches of planetary systems. I will discuss how the measurements of planet mass functions can be leveraged to constrain the formation conditions of planets including the composition and the dynamics of planetary embryos.
Co-Authors: Yayaati Chachan, Vincent Savignac
Exploring the obscured transient universe
By: Seppo Mattila
Type: Talk
Abstract: Characterization of dust-obscured extragalactic transient populations is of great interest for our understanding of galaxy formation and evolution. Tidal disruption events (TDEs) and supernovae (SNe) are expected at high rates in luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs, respectively) but are heavily obscured by interstellar dust and only accessible by radio and infrared observations with a sufficiently high spatial resolution. Local examples of such galaxies have been observed to host powerful SN factories within their innermost nuclear regions where massive stars with relatively short lifetimes are being formed in large numbers. Also, most (U)LIRGs are known to harbor at least one super massive black hole, and recent studies have identified strong candidates for heavily dust-obscured TDEs in their nuclei. We explore the potential of turning the NGRST into an efficient discovery machine of dust-obscured transients in (U)LIRGs at levels not possible in any previous surveys.
Probing the stellar graveyard and dark matter with astrometric microlensing
By: Peter McGill
Type: Talk
Abstract: The Galactic Bulge Time Domain Survey (GBTDS) will provide high cadence submilliarcseond astrometry of the Galactic Bulge. This presents an unprecedented opportunity to take advantage of the astrometric signatures of microlensing events. Astrometric microlensing has the potential to provide powerful and complimentary information beyond what it possible with photometry alone. I will present some of the benefits of having real-time GBTDS astrometry both simultaneously with photometry, and as probe on its own. I will focus on the implications for characterizing populations of dark and isolated objects such as neutrons stars, black holes, and compact dark matter.
Towards a Robust Tip of the Red Giant Branch Calibration in the Era of Roman
By: Max Newman
Type: Talk
Abstract: Galaxy distances are essential to placing galaxy properties on absolute scales and measuring the local expansion rate of the Universe (H_0), one of the Nancy Grace Roman Space Telescope's (Roman) main science requirements. To fulfill this goal we require precise distance indicators calibrated from galaxies with a range of properties and morphologies, such as the tip of the red giant branch (TRGB) method. Roman will provide exquisite data for measuring TRGB distances. However, the TRGB needs to be standardizable in the near-infrared (NIR) where its luminosity has a significant metallicity dependence.
We present our TRGB calibration methodology developed from both HST NIR and JWST data, demonstrate the robustness and precision of the calibrations, and discuss how Roman's large footprint enables us to overcome current challenges in measuring TRGB distances using small fields which can be impacted by low star counts, young stellar populations, and a limited range in stellar properties.
Co-Authors: Max J. B. Newman, Kristen B. W. McQuinn, Evan D. Skillman, Martha L. Boyer, Roger E. Cohen, Andrew E. Dolphin, O. Grace Telford
Toward the host star mass dependence of the planet frequency in Roman era
By: Kansuke Nunota
Type: Talk
Abstract: The dependence of planet frequency on the host star mass is crucial information for understanding the planet formation process but it has not been investigated for outer planets because ground-based microlensing surveys cannot measure the host star mass in most cases.
Roman is expected to discover more than 1000 planets and determine their masses in 60% of them. It may be possible to measure the dependence directly using the 60% sample, in which case the 40% events are difficult to use.
We developed a method that can measure the host mass dependence of planet frequency even without mass measurement and successfully measured it using 22 planets from a ground-based survey (Nunota et al. (2024)).
This method has the advantage that events with and without mass measurement can be easily combined, allowing us to analyze with a complete Roman sample. In this talk, I present the details of this method.
Co-Authors: Naoki Koshimoto, Daisuke Suzuki, Takahiro Sumi, David P. Bennett, Aparna Bhattacharya, Yuki Hirao, Sean K. Terry and Aikaterini Vandorou
The Milky Way As The z=0 template To Investigate Star and Planet Formation
By: Roberta Paladini
Type: Talk
Abstract: In January 2024 the Roman project announced that a Galactic Plane survey will be executed with the WFI instrument in approximately 700 hrs. The scientific community will work together to design the observational program ahead of Roman’s launch by May 2027.
This survey will enable a wide range of science cases at an unprecedented degree of accuracy and will challenge theory in many areas. For instance, the Roman unprecedented measurements will allow us to tackle the following questions: Is the process of star formation universal or affected by environment ? What is the role of spiral arms ? Is the Initial Mass Function universal ? Does the central Black Hole have a quenching effect on Star Formation in the Galactic bulge region?
In this talk, I will focus on a few specific science cases and will discuss their observational requirements.
Co-Authors: Sean Carey (Caltech-IPAC) Sergio Fajardo-Acosta (Caltech-IPAC) Luisa Rebull (Caltech-IPAC) Wanggi Lim (Caltech-IPAC) Andreas Faisst (Caltech-IPAC) Jennifer Sobeck (Caltech-IPAC)
Asteroseismology with the Galactic Bulge Time Domain Survey
By: Marc Pinsonneault
Type: Talk
Abstract: Asteroseismology is a powerful tool for studying stellar populations, and the Galactic Bulge Time Domain Survey (GBTDS) has the potential to measure stellar oscillations in large numbers of evolved red giant stars. I outline the opportunities and challenges for asteroseismic detection in the GBTDS. Key issues to overcome include saturated star photometry and the noise floor, especially for bright targets. Implications for survey design are discussed. Classical stellar characterization – abundances, luminosities, and surface temperatures - is also essential for taking full advantage of Roman asteroseismology, and I discuss the interplay between it and asteroseismology. In a companion talk, we discuss the modeling of Galactic bulge stellar populations with Roman.
Co-Authors: The Roman Asteroseismology Wide Field Science Team (Joel Zinn, UCSLB; Sanjib Sharma, JHU; Scott Gaudi, OSU; Matt Penny, LSU; Jennifer Johnson, OSU; Tim Bedding, U Sydney; Marc Hon, MIT; Dennis Stello, UNSW; Noah Downing, OSU; Trevor Weiss, UCSLB.)
High Energy Physics at the High Number Density Frontier
By: Zachary Slepian
Type: Talk
Abstract: Roman's high redshift reach and high number density will offer unique leverage on the physics of the very early Universe: inflation, an epoch of exponential expansion at energy scales higher than any probed by terrestrial accelerators. I will discuss my group's recent work investigating parity violation during inflation---whether beyond-Standard Model physics gives the Universe a preference for one ``handedness'' in how galaxies cluster. The galaxy 4-point correlation allows us to answer this question, and Roman will provide an outstanding future laboratory to do so.
Variable stars in M31 stellar clusters
By: Richard David Smith
Type: Talk
Abstract: Variable stars in stellar clusters can offer key constraints on stellar evolution and pulsation models. We will present the first systematic study of variable stars in extragalactic stellar clusters leveraging the superior resolution of the Hubble Space Telescope by mining the archival Panchromatic Hubble Andromeda Treasury (PHAT) survey. We produce a catalogue of 89 luminous variable stars within M31 stellar clusters, identified using a combination of sparse PHAT light curve data and difference imaging, and characterized using their host cluster properties available in the literature. Our results demonstrate the unique power of stellar clusters in constraining variable star properties and the continued potential for space-based observatories in this area. We will highlight how Roman observations of M31 could be used to expand the PHAT survey further and enhance its utility as a time-domain resource, improving our understanding of variable stars both in cluster environments and in the field.
Co-Authors: Avi Patel Monika Soraisam
Dark Scattering: accelerated constraints from KiDS-1000 with REACT and COSMOPOWER
By: Alessio Spurio Mancini
Type: Talk
Abstract: We present constraints on the Dark Scattering model through cosmic shear measurements from the Kilo Degree Survey (KiDS-1000), using an accelerated pipeline with novel emulators produced with COSMOPOWER. Our main emulator, for the Dark Scattering non-linear matter power spectrum, is trained on predictions from the halo model reaction framework, previously validated against simulations. Additionally, we include the effects of baryonic feedback from HMCODE, whose contribution is also emulated.
We analyse the complete set of statistics of KiDS-1000 for Dark Scattering. We constrain the amplitude of the dark energy -- dark matter interaction to be <20 b/GeV at 68\%C.L.
Furthermore, we add information from the cosmic microwave background (CMB) from Planck, along with baryon acoustic oscillations (BAO) from 6dFGS, SDSS and BOSS, approximating a combined weak lensing + CMB + BAO analysis. We confirm that the interacting model considered in this work offers a promising alternative to solve the S_8 tension.
Co-Authors: Alessio Spurio Mancini Karim Carrion Pedro Carrilho Carlos Hidalgo Alkistis Purtsidou
COSMOPOWER: Deep Learning -- accelerated Bayesian cosmology for next-generation surveys
By: Alessio Spurio Mancini
Type: Talk
Abstract: I will present COSMOPOWER, a Deep Learning framework for accelerated statistical inference from cosmological surveys. COSMOPOWER provides orders-of-magnitude acceleration to the inference pipeline by training neural emulators of cosmological power spectra and using them to accelerate the expensive computation of these quantities, usually performed with Boltzmann codes.
I will show how COSMOPOWER's differentiable emulators combined with probabilistic programming enable scalable and efficient statistical inference by means of hierarchical forward modelling and simulation-based inference. Leveraging the benefits of automatic differentiation, XLA optimisation, and the ability to run on GPUs and TPUs, COSMOPOWER allows for efficient sampling through gradient-based methods. I will demonstrate with applications to simulated Stage IV joint probe analyses how COSMOPOWER enables the construction of end-to-end pipelines for parameter estimation and model comparison with unparalleled accuracy. This is achieved by efficiently sampling unprecedentedly large numbers of nuisance parameters for the rigorous modelling of systematic effects.
Co-Authors: Alessio Spurio Mancini
Uncovering the details of galaxy formation and stellar halos with Roman
By: Tjitske Starkenburg
Type: Talk
Abstract: The Nancy Grace Roman Space Telescope will provide a detailed view of galaxies, providing insights on their stellar populations, and gas and dust properties. In the Local Universe, Roman’s large field of view, sensitivity and resolution opens up a unique opportunity to study galaxies’ large but faint stellar halos.
Stellar halos are rich records of their host galaxy’s history: smaller galaxies are stripped apart in the outskirts of their larger hosts, leaving their stars as tracers of their origin. These stellar streams and substructures are sensitive to the underlying gravitational potential, providing constraints on the nature of dark matter and galaxy formation physics. In this talk I will highlight how using a variety of modeling techniques can aid in understanding physical processes in hierarchical galaxy formation and their link to observational signatures. These insights and predictions will facilitate the observational interpretation and identify how Roman observations could constrain theory.
Status of JAXA contributions to Roman Space Telescope
By: Takahiro Sumi
Type: Talk
Abstract: The JAXA Roman-J Project Team is participating in Roman Space Telescope with contributions from
(1) Synergistic observations by using 100 nights of Subaru telescope,
(2) Ground-based microlensing data release by MOA collaboration,
(3) The precursor and concurrent microlensing observation by PRIME telescope,
(4) The optics for the coronagraph instruments,
(5) The data downlink by JAXA ground station.
(6) Participating in the Roman science teams and CCP.
This presentation will report on the current status of these project.
Co-Authors: JAXA Roman Project
Synergy between PRIME and Roman
By: Daisuke Suzuki
Type: Poster
Abstract: The PRIME telescope is a 1.8m, prime-focus near-infrared (NIR) telescope with a wide FOV to conduct the microlensing planet survey toward the Galactic center and bulge. The PRIME microlensing survey started in 2024 with H-band. PRIME is important to enhance the Roman’s science in several aspects. First, the NIR microlensing event rate map will be derived from the initial data of the PRIME survey to optimize the Roman Galactic Bulge Domain Survey field. Second, concurrent observations with Roman will measure the microlensing parallax, which is complementary to the Roman’s own measurement and critical to derive the mass of the free-floating planets. Third, PRIME can cover the light curve of the long time scale events during the summer. Finally, the four H4RG-10 detectors PRIME is using in its prime-focus camera allow us to study the detector behavior. In the poster, we will summarize and discuss the above topics.
Co-Authors: Takahiro Sumi, Naoki Koshimoto, Alexander Kutyrev, Gregory Mosby, Joseph Durbak, and David Bennett
Line Intensity Mapping Cross-correlations in the Era of Wide-field Galaxy Surveys
By: Rakshitha Thaman
Type: Talk
Abstract: Roman is anticipated to bring transformative insights to the study of large-scale structure (LSS) and cosmology with its superb capabilities and unprecedented field of view. One approach to maximize Roman’s scientific return is to harness the synergy with line intensity mapping (LIM), which accounts for emission from all galaxies along the line of sight. Cross-correlation of Roman galaxy maps and LIM can be used to extract robust constraints for both galaxy evolution and cosmology across cosmic time. We explore creating forecasts for these cross-correlations using simulated past lightcones constructed with the physically-backed, versatile Santa Cruz semi-analytic models (SAM), which requires only a small fraction of computational resources and is more viable compared to conventional hydrodynamic simulations. We will present forecasts for the cross-power spectrum between mock Roman galaxy survey and CII LIMs anticipated by EXCLAIM, a NASA balloon-borne mission.
Co-Authors: L.Y. Aaron Yung, Anthony Pullen
Synthetic survey catalogs for the Galactic Roman Infrared Plane Survey (GRIPS) using py-ananke
By: Adrien Christian Rene Thob
Type: Talk
Abstract: With Roman's imminent launch, exploring the crowded and obscured Galactic plane will reach unprecedented depths, thanks to the recent definition of a survey of that region. 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 dust extinction and observational uncertainties. We generate the surveys from MW-like galaxies in the Latte suite of FIRE cosmological simulations, placing the solar viewpoint at varied positions within each galaxy and mirroring the footprint of GRIPS. We provide WFI photometry and proper motions based on a proposed survey cadence. We anticipate these synthetic surveys to serve as a robust testbed for survey planning and the refinement of analysis and reduction pipelines for GRIPS. We discuss features of the surveys, including their similarities/differences from known features of our Galaxy, and outline the available tools for accessing them.
Co-Authors: Adrien Thob, Robyn Sanderson
Dark Matter and Cosmology from Strong Lenses in the age of Roman
By: Tommaso Treu
Type: Talk
Abstract: Strong lenses have been shown to be a unique tool for study of dark matter and the expansion history of the universe. One the one hand, they measure matter fluctuations on subgalactic scales and thus probe whether the dark halos predicted by standard cold dark matter are real or whether alternative dark matter model must be considered. On the other hand, time delays measure the expansion history of the universe, and therefore cosmological parameters from the Hubble constant to the equation of state of dark energy. Both applications have been thus far limited by the small number of known suitable lenses. Roman will revolutionize the field by increasing the number of targets by 1 or 2 order of magnitude and by providing high resolution imaging and spectroscopy. I will review the current state of affairs and give a sneak preview of the Roman strong lensing revolution.
Enabling Roman science now: New synthetic Roman+Rubin surveys
By: Michael Troxel
Type: Talk
Abstract: Individual and potentially joint pixel-level processing, calibration, and analysis of the Roman Space Telescope and other next-generation surveys like the Rubin Observatory LSST will require substantial development and testing. To ensure the first data releases are ready for science, work must begin now to develop the calibrations and tools required to take full advantage of the data. I will describe a successful joint NASA-DOE campaign led by OpenUniverse to prepare synthetic deep- and wide-area surveys for Roman and Rubin containing three million simulated images overlapping the same synthetic sky, as well as future work and improvements in simulating the Roman Space Telescope for cosmology and other science areas.
Co-Authors: OpenUniverse, LSST DESC, and the Roman SN & WL PITs
Roman Alerts Promptly from Image Differencing (RAPID)
By: Schuyler D Van Dyk
Type: Poster
Abstract: RAPID is a Roman Project Infrastructure Team, based entirely at Caltech. The Astro2020 Decadal Survey identified time-domain and multi-messenger science as a high priority. RAPID will enable a wide suite of dynamic-sky science for Roman. The RAPID team has experience providing services to the global time-domain community and is leveraging previous work on other projects, particularly the Zwicky Transient Facility. Our goal is to provide four services to the Roman community: rapid, low-latency image-differencing of every new Roman image from a reference image; a prompt public alert stream of all Roman transient and variable candidates; source-matched light curve files for every identified Roman candidate; and, a forced-photometry service for the photometric history at any observed sky location. RAPID can be found at https://rapid.ipac.caltech.edu.
Co-Authors: Jacob Jencson (IPAC/Caltech), Mansi Kasliwal (Caltech), Russ Laher (IPAC/Caltech), Ashish Mahabal (Caltech), Joe Masiero (IPAC/Caltech), Roberta Paladini (IPAC/Caltech), Ben Rusholme (IPAC/Caltech), Lin Yan (Caltech)
The Roman View of Strong Gravitational Lenses
By: Bryce Wedig
Type: Talk
Abstract: We present a population survey and simulated images of galaxy-galaxy strong gravitational lenses detectable by Roman. Strong gravitational lensing is a powerful tool for constraining dark matter models and the Lambda Cold Dark Matter cosmological paradigm at sub-galactic scales. Roman is uniquely suited to characterizing dark matter substructure in strong lenses with its high, diffraction-limited angular resolution. We simulate a population of galaxy-galaxy strong lenses across cosmic time with Cold Dark Matter subhalo populations, then select those detectable in Roman's High Latitude Wide Area Survey and generate realistic simulated images of them. We account for realistic Wide Field Instrument detector effects, such as variation of the point spread function across Roman's 0.281 square degree field of view. An accurate yield simulation with associated images of strong lenses will support future strong lens science with Roman, such as training neural networks and validating dark matter substructure analysis pipelines.
Co-Authors: Tansu Daylan In collaboration with Simon Birrer and Rahul Karthik
Modeling Emission Line Galaxies with Galacticus Semi Analytic Model
By: Sachithra Ishani Weerasooriya
Type: Poster
Abstract: Accurately determining emission line galaxy densities is essential for optimizing galaxy surveys, particularly with the Roman Space Telescope. This study presents an enhanced emission line model for star-forming galaxies with the semi-analytic model Galacticus (Benson 2012). We use a precomputed grid of emission line luminosities generated with Cloudy (Ferland et al. 1998) to calculate the HII region luminosities. Our approach involves calculating emission line luminosities by integrating each emission line's HII region luminosity and star formation history over ages and metallicities. We calibrate our model against observed relations, including the mass-metallicity relation and star formation rate functions. Our preliminary results successfully reproduce the luminosity functions of Halpha, NII, and OII emission lines, closely matching observations by Favole et al. in 2024 at z=0.05.
Co-Authors: Andrew Benson
Modeling Asteroseismic Yields of the Roman Galactic Bulge Time-Domain Survey
By: Trevor Weiss
Type: Poster
Abstract: The Nancy Grace Roman Space Telescope’s Galactic Bulge Time-Domain Survey will inform a wide range of fields in astrophysics, thanks in particular to its asteroseismic capabilities. Of special interest is the ongoing discussion regarding the possibility of a young stellar population in the bulge. Asteroseismic data promise to settle the debate by providing precise stellar ages, independent of existing photometric- and spectroscopic-based analyses. We describe expected asteroseismic yields for the Galactic Bulge Time-Domain Survey, investigating the effects of survey strategy, filter choice, noise properties, and helium abundance. 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, which suggests even the asteroseismology yields themselves may place interesting constraints on the bulge age distribution. The resulting asteroseismic ages will also inform competing models of planet formation and evolution when combined with Roman’s expected microlensing planet yields.
Co-Authors: Roman Asteroseismology Wide Field Science Team (Tim Bedding, Kaili Cao, Noah Downing, Scott Gaudi, Marc Hon, Daniel Huber, Jennifer Johnson, Matthew Penny, Marc Pinsonneault, Sanjib Sharma, Dennis Stello, Joel C. Zinn)
Transits in the Roman galactic EXoplanet Survey (TRExS): Smashing Planet Formation and Evolution Theories with a Demographics Hammer
By: Robert F Wilson
Type: Talk
Abstract: Recent pixel-level simulations predict that the Galactic Bulge Time Domain Survey (GBTDS) will facilitate the discovery of ~100,000 hot and warm transiting exoplanets, providing the means to challenge theories of planet formation (e.g., core accretion), destruction (e.g., tidal migration), and atmospheric circulation via a brute-force statistical hammer. With an expected sample size sufficient to detect systems with occurrence rates as low as one in a million, the GBTDS will facilitate population-level studies of exoplanets in intrinsically rare systems and in the midst of shortly-lived evolutionary phases, providing the means to "nail" down uncertainties in migration timescales and occurrence rates critical to understanding the giant planet population. I will present these scientific motivations from the TRExS collaboration and our ongoing efforts to prepare for this rich dataset, including analytical and pixel-level simulations, infrastructure development, and plans to address existing knowledge gaps.
Co-Authors: Elisa Quintana, Nestor Espinoza, Kelsey Hoffman, Eamonn Kerins, Jorge Martinez-Palomera, Ben Montet, Susan Mullally, Matthew Penny, Tom Barclay, Kylee Carden, Yiwei Chai, Jessie Christiansen, David Ciardi, Scott Gaudi, Christina Hedges, Macy Huston, Veselin Kostov, Dana Louie, Iain McDonald, Brett Morris, Marz Newman, Brian Powell, Akshay Priyadarshi, Jason Rowe, Joshua Schlieder, Allison Youngblood, Rob Zellem
Simulating a Roman Space Telescope Survey of Nearby Galaxies
By: Kathryn Wynn
Type: Poster
Abstract: The launch of the Nancy Grace Roman Space Telescope (Roman) will soon allow us to observe large areas of the stellar halos of nearby galaxies in hours rather than months. To better leverage these observations, we are developing a pipeline that uses STScI-STIPS software to simulate Roman observations of nearby galaxies and then measures their resolved stellar photometry. Our early testing uses input catalogs of mock dwarf galaxies added to Bullock and Johnston halos as well as halos generated from numerical simulations similar to the nearby spiral galaxy M81. The goal of this pipeline is to provide tools to help determine the observational strategy to resolve structures in extended stellar halos of nearby galaxies, which are sensitive to dark matter halo structure and galaxy accretion histories. This work is part of Roman Infrared Nearby Galaxies Survey (RINGS), a Wide-Field Science (WFS) program funded by NASA under grant 80NSSC24K0084.
Co-Authors: Benjamin Williams, Eric Bell, David Sand, Roman Infrared Nearby Galaxies Survey (RINGS) Team
The Microlensing Planet Landscape on the Eve of Roman
By: Jennifer C Yee
Type: Talk
Abstract: The microlensing planet landscape has changed dramatically since the 2010 Decadal Survey recommended a space-based microlensing mission as a top priority. I will review that evolution with a particular focus on the current exoplanet demographic constraints from microlensing and explore the new regimes that can be uniquely probed by the planned Roman Galactic Bulge Time Domain Survey.
The Coherent Differential Imaging on Speckle Area Nulling (CDI-SAN) method for Suppression of Fluctuating Speckles
By: Kenta Yoneta
Type: Poster
Abstract: For direct detection of exoplanets, we are developing a new technique called the Coherent Differential Imaging on Speckle Area Nulling (CDI-SAN) method to suppress scattered stellar light (speckles) fluctuating during wavefront sensing and control. In the CDI-SAN method, 5 (10) focal plane intensity measurements synchronized with 5 wavefront controls are performed faster than speckle fluctuation. Fluctuating speckles are suppressed by the post-processing using the integral values obtained by repeatedly performed these controls and measurements. Numerical simulations have shown that the CDI-SAN method can suppress fluctuating speckles to the photon noise limit and detect exoplanets hidden by speckles. We are conducting a demonstration of the CDI-SAN method using a new testbed constructed in our laboratory. We will report the progress of the laboratory demonstration.
Co-Authors: Kenta Yoneta, Jun Nishikawa, Yutaka Hayano, Masatsugu Iribe, Kodai Yamamoto, Ryo Tsukui, Naoshi Murakami, Mizuki Asano, Yosuke Tanaka, Motohide Tamura, Takahiro Sumi, Toru Yamada, Olivier Guyon, Julien Lozi, Vincent Deo, Sebastien Vievard, Kyohoon Ahn
Science cases motivating future deep-wide Roman surveys for galaxy formation and evolution
By: L. Y. Aaron Yung
Type: Talk
Abstract: Roman is the only planned observatory that has the field of view and spatial resolution to uniquely enable extragalactic surveys reaching HUDF depths over multiple deg^2. In the recent call for input into Roman’s Core Community Surveys, many voiced their interest and proposed science cases for a Roman deep field. In this talk, I will use the results from a set of Roman deep lightcones simulated with semi-analytic models, which covers a total area of 10 deg^2 and resolves galaxies down to m_F184~30 at z=6, to demonstrate the scientific return of deep galaxy surveys. I will also discuss synergies with Euclid and Rubin that are backed by these simulations. I will also discuss how Roman in the near future will be able to confront and refine models that are inspired by recent JWST observations, including alternative star formation and feedback models, as well as black hole seeding and growth models.
Updates on The Expected Yield Estimates of Bound Planets for Roman
By: Farzaneh Zohrabi
Type: Talk
Abstract: One of the primary objectives of NASA’s Roman Space Telescope is to conduct a comprehensive statistical survey of cold, low-mass exoplanets. In this presentation, we provide an update on the expected yield of bound planets for Roman, utilizing the GULLS gravitational microlensing simulator. Our simulations benefit from an improved Galactic model, as properties and rates of microlensing events are directly influenced by the Galactic model’s uncertainties. This refined yield estimates incorporate our latest understanding of the observatory, including changes to its observational strategy and instrument configuration, which are necessary for optimizing detection efficiency. Additionally, we are updating the fiducial mass function, fiducial joint mass–semimajor axis occurrence distribution, and will discuss its impact on calculating the expected yield of bound planets for Roman.
Co-Authors: Farzaneh Zohrabi, Matthew Penny
