Bibliographic Details
| Title: |
Scylla II. The Spatially Resolved Star Formation History of the Large Magellanic Cloud Reveals an Inverted Radial Age Gradient |
| Authors: |
Cohen, Roger E., McQuinn, Kristen B. W., Murray, Claire E., Williams, Benjamin F., Choi, Yumi, Lindberg, Christina W., Burhenne, Clare, Gordon, Karl D., Merica-Jones, Petia Yanchulova, Gilbert, Karoline M., Boyer, Martha L., Goldman, Steven, Dolphin, Andrew E., Telford, O. Grace |
| Publication Year: |
2024 |
| Collection: |
Astrophysics |
| Subject Terms: |
Astrophysics - Astrophysics of Galaxies |
| More Details: |
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 (HST) 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 (CMDs) 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 $\sim$2 disk scalelengths, supported by ground-based measurements. The gradients become relatively flatter at earlier lookback times, while the location of the inversion remains constant over an order of magnitude in lookback time, from $\sim$1$-$10 Gyr. This suggests at least one mechanism that predates the recent intense LMC-SMC 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.
Comment: ApJ in press. 45 pages, 17 figures, 9 tables including Appendices |
| Document Type: |
Working Paper |
| Access URL: |
http://arxiv.org/abs/2410.11696 |
| Accession Number: |
edsarx.2410.11696 |
| Database: |
arXiv |
