Ipac logo
A Legacy Survey of Andromeda and Triangulum with Roman
Program ID 2002
Science Category Stellar Populations
Program Type GAS
Hours 310.7
Category Large
Principal Investigator Karoline Gilbert
PI Institution Space Telescope Science Institute / STScI
Co-Investigators
  • Christopher Garling (University of Virginia)
  • Molly Peeples (Space Telescope Science Institute / STScI)
  • Laura Watkins (Space Telescope Science Institute / STScI / AURA for ESA)
  • Rachael Beaton (Space Telescope Science Institute / STScI)
  • Fatemeh Zahra Majidi (INAF-OACN)
  • Edward Schlafly (Space Telescope Science Institute / STScI)
  • Denis Leahy (University of Calgary)
  • Abigail Lee (University of California, Berkeley)
  • Claire Murray (Space Telescope Science Institute / STScI)
  • Andrea Bellini (Space Telescope Science Institute / STScI)
  • Roeland Van Der Marel (Space Telescope Science Institute / STScI)
  • Meredith Durbin (University of California, Berkeley)
  • Massimo Griggio (Space Telescope Science Institute / STScI)
  • Monika Soraisam (NSF NOIRLab)
  • Maude Gull (Carnegie Observatories / Caltech)
  • Andrew Wetzel (University of California, Davis)
  • Margaret Lazzarini (California State University, Los Angeles)
  • Raja GuhaThakurta (University of California, Santa Cruz)
  • Roger Cohen (Eureka Scientific)
  • Oleg Gnedin (University of Michigan)
  • Luigi (Rolly) Bedin (Osservatorio Astronomico di Padova / OAPd / INAF)
  • Mattia Libralato (Osservatorio Astronomico di Padova / OAPd / INAF)
  • Sarah Pearson (DARK, Niels Bohr Insitute)
  • Jose Diego (Instituto de Fisica de Cantabria (CSIC-UC))
  • Kristen McQuinn (Space Telescope Science Institute / STScI)
  • Daniel Weisz (University of California, Berkeley)
  • John Wu (Space Telescope Science Institute / STScI)
  • Jack Warfield (University of Virginia)
  • Nitya Kallivayalil (University of Virginia)
  • Steven Majewski (University of Virginia)
  • Steven Goldman (Space Telescope Science Institute / STScI)
  • Tom Brown (Space Telescope Science Institute / STScI)
  • Ekta Patel (Villanova University)
  • Christopher Clark (Space Telescope Science Institute / STScI / AURA for ESA)
  • Evan Kirby (University of Notre Dame)
  • Benjamin Williams (Unversity of Washington)
  • Gagandeep Anand (Space Telescope Science Institute / STScI)
  • Grace Telford (University of Utah)
  • Thavisha Dharmawardena (Monash University)
  • Andrew Dolphin (Raytheon)
  • Matteo Monelli (Osservatorio d'Abruzzo / INAF)
  • Marcella Di Criscienzo (Osservatorio di Roma / INAF)
  • Giuliana Fiorentino (Osservatorio di Roma / INAF)
  • Giuseppe Bono (Università di Tor Vergata)
  • Vittorio Francesco Braga (Osservatorio di Roma / INAF)
  • Maria Tantalo (Osservatorio di Roma / INAF)
  • Christina Lindberg (Harvard-Smithsonian Center for Astrophysics)
  • Valentin Ivanov (European Southern Observatory, Garching)
  • Daniel Dale (University of Wyoming)
  • Tjitske Starkenburg (Northwestern University)
  • Ata Sarajedini (Florida Atlantic University)
  • Michelle Collins (University of Surrey)
  • Elizabeth Tarantino (Space Telescope Science Institute / STScI)
  • Daniel Hey (University of Hawaii)
  • Richard Smith (University of Chicago)
  • Adam Riess (Johns Hopkins University)
  • Adam Leroy (Ohio State University)
  • Laszlo Molnar (Konkoly Observatory, HUN-REN CSFK)
  • Avi Patel (University of California, Santa Cruz)
  • Neill Reid (Space Telescope Science Institute / STScI)
  • Andrew Pace (University of Virginia)
  • Andrew Fox (Space Telescope Science Institute / STScI / AURA for ESA)
  • Luciana Bianchi (Dept of Physics & Astronomy, Johns Hopkins University)
  • Alessandro Savino (University of California, Berkeley)
  • Eduardo Vitral (University of Edinburgh)
  • Paul Bennet (Space Telescope Science Institute / STScI)
  • Yumi Choi (NSF NOIRLab)
  • Sakurako Okamoto (National Astronomical Observatory of Japan)
  • Adrien Thob (University of Pennsylvania)
  • Jennifer Sobeck (IPAC / Caltech)
  • Tony Sohn (Space Telescope Science Institute / STScI)
  • Daniel Huber (University of Hawaii)
  • Masashi Chiba (Tohoku University)
  • Itsuki Ogami (National Astronomical Observatory of Japan)
  • Julianne Dalcanton (Flatiron Institute)
  • Richard D'Souza (Vatican Observatory)
  • Médéric Boquien (Université Côte d'Azur)
  • Andrés del Pino Molina (Instituto de Astrofísica de Andalucía (IAA-CSIC))
  • Francois Hammer (LIRA Paris Observatory)
  • Yanbin Yang (LIRA Paris Observatory)
  • Charis Tsakonas (National and Kapodistrian University of Athens)
  • Mark Fardal (Eureka Scientific)
  • Burcin Mutlu-Pakdil (Dartmouth College)
  • Mishra Sapna (Space Telescope Science Institute / STScI)
  • Karl Gordon (Space Telescope Science Institute / STScI)
  • Alis Deason (Durham University)
  • Aaron Romanowsky (San Jose State University)
  • Carme Gallart (Instituto de Astrofísica de Canarias)
  • David Mirabal (Instituto de Astrofísica de Canarias)
  • Erik Rosolowsky (University of Alberta)
  • Zhuo Chen (Unversity of Washington)
  • Martin Makler (Brazilian Center for Physics Research)
  • Benjamin Keller (University of Memphis)
  • Katie Sharpe (University of California, Berkeley)
  • Annette Ferguson (University of Edinburgh)
  • Jeffrey Carlin (Rubin Observatory / NSF NOIRLab)
  • Petia Yanchulova Merica-Jones (Institute of Astronomy)
  • Lara Cullinane (Leibniz-Institute for Astrophysics Potsdam)
  • Massimo Marengo (Florida State University)
  • Ivanna Escala (Space Telescope Science Institute / STScI)
  • Rebecca Levy (Space Telescope Science Institute / STScI)
  • Steven Gough-Kelly (Jeremiah Horrocks Institute, Univserity of Lancashire)
  • Kishalay De (Columbia University)
  • Borja Anguiano (Centro de Estudios de Fisica del Cosmos de Aragon (CEFCA))
  • Sharma Sanjib (Space Telescope Science Institute / STScI)
  • Benjamin Gibson (Space Telescope Science Institute / STScI)
  • Kevin McKinnon (University of Toronto)
  • Max Newman (Space Telescope Science Institute / STScI)
  • William DeRocco (University of Maryland, College Park)
  • Morgan Fouesneau (Max Planck Institute for Astronomy)
  • Giada Pastorelli (Osservatorio Astronomico di Padova / OAPd / INAF)
  • Leo Girardi (Osservatorio Astronomico di Padova / OAPd / INAF)
  • Guglielmo Costa (University of Padova)
  • Michele Trabucchi (University of Padova)
  • Clara Martinez-Vazquez (NSF NOIRLab)
  • Peter Scicluna (Space Science Institute)
  • Amy Miller (University of Florida)
  • Elizabeth Lada (University of Florida)
  • Antoniya Valcheva (Sofia University 'St. Kliment Ohridski')
  • L. Clifton Johnson (Northwestern University)
  • Xiaolong Li (Johns Hopkins University)
  • Anna Wright (Flatiron Institute)
  • Rodrigo Angulo (Johns Hopkins University)
  • Martha Boyer (Space Telescope Science Institute / STScI)
  • Adam Smercina (Space Telescope Science Institute / STScI)
  • Massimo Ricotti (University of Maryland, College Park)
  • Jay Anderson (Space Telescope Science Institute / STScI)
  • Amandine Doliva-Dolinsky (University of Surrey)
  • Arjun Dey (NSF NOIRLab)
  • Christian Aganze (KIPAC / Stanford)
  • Antonela Monachesi (Universidad de La Serena)
  • Nathan Sandford (University of Toronto)
  • Eric Bell (University of Michigan)
  • Dieu Nguyen (University of Michigan)
  • Armin Rest (Space Telescope Science Institute / STScI)
  • Jeremiah Murphy (Florida State University)
  • Anna Barbara Queiroz (Instituto de Astrofísica de Canarias)
  • Jiayi Sun (University of Kentucky)
  • Erik Tollerud (Space Telescope Science Institute / STScI)
  • Sarah Loebman (University of California, Merced)
Abstract Our knowledge of the astrophysical processes underpinning the growth and evolution of galaxies is anchored by observations of the Local Group. As the nearest spirals outside our Milky Way, Andromeda (M31) and Triangulum (M33) provide the richest possible targets for expanding our detailed understanding of stars, stellar evolution, the dusty ISM, feedback, dark matter physics, and small-scale cosmology, at spatial resolutions and sensitivities that are unavailable for any massive galaxies outside the Milky Way. This proposal leverages Roman's survey speed, high spatial resolution, and NIR coverage to deliver multi-epoch photometry for more than half a billion stars across the M31 and M33 system through: (1) wide-area two-filter, two-epoch imaging, covering the entirety of the stellar disks and inner halo regions; (2) panchromatic SEDs over the entirety of their HI disks; (3) deep fields anchoring the ancient star formation in both galaxies, and (4) ground-breaking studies of variability in M31's star-forming disk. When integrated into M31+M33's rich archival imaging and spectroscopy (spanning the X-ray to the radio), Roman data products will transform our understanding of their interconnected dynamical history, evolving disk structure, and stellar and ISM constituents. The maximum impact for first-epoch M31+M33 observations is Cycle 1, to yield the longest possible time baseline for proper motions and variability studies. These enable (1) full modeling of the dynamical accretion history of M31+M33 by bringing Gaia-like phase-space data to the other dominant galaxies in the Local Group, and (2) mapping the 3D disk structure, using pioneering individual distance measurements to RGB stars. This early, rich dataset will fundamentally shift the level at which we understand stars in the NIR and the galaxies most sensitive to departures from CDM, fueling subsequent generations of rigorous and transformative studies with Roman and JWST, from parsec to megaparsec scales.
Summary of Observations This survey comprises 4 observational components, each of which employs separate dithering, cadence, depth, and exposure strategies. (1) Contiguous wide-area imaging observations covering 50.5 (5.6) sq. deg. in M31's (M33's) inner halo regions, with a 2-filter (F062, F129) first epoch and a 1-filter (F129) 2nd epoch at the end of the primary mission, with at least a 4 year (preferably 4.5 year) baseline between the two epochs (charged time 172.22 hours). (2) Additional imaging observations covering the HI disks of M31 and M33 (7.5 and 0.94 sq. deg.), with the 5 normal-width filters not included in the wide-area imaging, as well as additional sub-pixel dithers in F062 (charged time 60.11 hours). (3) A time-domain imaging component in F087 and F213, with low-cadence observations (4 epochs per year in each filter) covering the full star-forming disk (1.7 sq. deg.) of M31 over the full five years of the prime mission, as well as 1 high-cadence pointing (24 epochs per year in F087, 4 in F213) observed over 2 years (charged time 38.93 hours). (4) Two deep fields, one each in M31 and M33, reaching the oMSTO in F062 and F158 with epochs cadenced for RRLy characterization (charged time 39.43 hours).
Status of Observations https://www.stsci.edu/roman-program-info/program/?program=2002