Scylla. II. The Spatially Resolved Star Formation History of the Large Magellanic Cloud Reveals an Inverted Radial Age Gradient

Roger E. Cohen; Kristen B. W. McQuinn; Claire E. Murray; Benjamin F. Williams; Yumi Choi; Christina W. Lindberg; Clare Burhenne; Karl D. Gordon; Petia Yanchulova Merica-Jones; Karoline M. Gilbert; Martha L. Boyer; Steven Goldman; Andrew E. Dolphin; O. Grace Telford

doi:10.3847/1538-4357/ad6cd5

The Astrophysical Journal (Jan 2024)

Scylla. II. The Spatially Resolved Star Formation History of the Large Magellanic Cloud Reveals an Inverted Radial Age Gradient

Roger E. Cohen,
Kristen B. W. McQuinn,
Claire E. Murray,
Benjamin F. Williams,
Yumi Choi,
Christina W. Lindberg,
Clare Burhenne,
Karl D. Gordon,
Petia Yanchulova Merica-Jones,
Karoline M. Gilbert,
Martha L. Boyer,
Steven Goldman,
Andrew E. Dolphin,
O. Grace Telford

Affiliations

Roger E. Cohen: ORCiD; Department of Physics and Astronomy, Rutgers the State University of New Jersey , 136 Frelinghuysen Rd., Piscataway, NJ 08854, USA ; [email protected]
Kristen B. W. McQuinn: ORCiD; Department of Physics and Astronomy, Rutgers the State University of New Jersey , 136 Frelinghuysen Rd., Piscataway, NJ 08854, USA ; [email protected]; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
Claire E. Murray: ORCiD; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA; The William H. Miller III Department of Physics & Astronomy, Bloomberg Center for Physics and Astronomy, Johns Hopkins University , 3400 N. Charles Street, Baltimore, MD 21218, USA
Benjamin F. Williams: ORCiD; Department of Astronomy, University of Washington , Box 351580, U. W., Seattle, WA 98195-1580, USA
Yumi Choi: NSF’s National Optical-Infrared Astronomy Research Laboratory , 950 N. Cherry Avenue, Tucson, AZ 85719, USA
Christina W. Lindberg: ORCiD; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA; The William H. Miller III Department of Physics & Astronomy, Bloomberg Center for Physics and Astronomy, Johns Hopkins University , 3400 N. Charles Street, Baltimore, MD 21218, USA
Clare Burhenne: Department of Physics and Astronomy, Rutgers the State University of New Jersey , 136 Frelinghuysen Rd., Piscataway, NJ 08854, USA ; [email protected]
Karl D. Gordon: ORCiD; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
Petia Yanchulova Merica-Jones: ORCiD; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
Karoline M. Gilbert: ORCiD; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
Martha L. Boyer: ORCiD; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
Steven Goldman: ORCiD; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
Andrew E. Dolphin: ORCiD; Raytheon , 1151 E. Hermans Road, Tucson, AZ 85756, USA; University of Arizona , Steward Observatory, 933 North Cherry Avenue, Tucson, AZ 85721, USA
O. Grace Telford: ORCiD; Department of Physics and Astronomy, Rutgers the State University of New Jersey , 136 Frelinghuysen Rd., Piscataway, NJ 08854, USA ; [email protected]; Department of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08544, USA; The Observatories of the Carnegie Institution for Science , 813 Santa Barbara Street, Pasadena, CA 91101, USA

DOI: https://doi.org/10.3847/1538-4357/ad6cd5
Journal volume & issue: Vol. 975, no. 1
p. 42

Abstract

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The proximity of the Magellanic Clouds provides the opportunity to study interacting dwarf galaxies near a massive host, and spatial trends in their stellar population properties in particular, with a unique level of detail. The Scylla pure parallel program has obtained deep (80% complete to >1 mag below the ancient main-sequence turnoff), homogeneous two-filter Hubble Space Telescope imaging sampling the inner star-forming disk of the Large Magellanic Cloud (LMC), the perfect complement to shallower, contiguous ground-based surveys. We harness this imaging together with extant archival data and fit lifetime star formation histories (SFHs) to resolved color–magnitude diagrams of 111 individual fields, using three different stellar evolutionary libraries. We validate per-field recovered distances and extinctions, as well as the combined global LMC age–metallicity relation and SFH against independent estimates. We find that the present-day radial age gradient reverses from an inside-out gradient in the inner disk to an outside-in gradient beyond ∼2 disk scale lengths, supported by ground-based measurements. The gradients become relatively flatter at earlier look-back times, while the location of the inversion remains constant over an order of magnitude in look-back time, from ∼1 to 10 Gyr. This suggests at least one mechanism that predates the recent intense LMC–Small Magellanic Cloud interaction. We compare observed radial age trends to other late-type galaxies at fixed stellar mass and discuss similarities and differences in the context of potential drivers, implying strong radial migration in the LMC.

Published in The Astrophysical Journal

ISSN: 1538-4357 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Astronomy: Astrophysics
Website: https://iopscience.iop.org/journal/0004-637X

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