Bibliographic Details
| Title: |
Revealing the Chemical Structure of the Magellanic Clouds with APOGEE. I. Calculating Individual Stellar Ages of RGB Stars in the Large Magellanic Cloud |
| Authors: |
Povick, Joshua T., Nidever, David L., Massana, Pol, Tayar, Jamie, Olsen, Knut A. G., Hasselquist, Sten, Cioni, Maria-Rosa L., Nitschelm, Christian, Carrera, Ricardo, Choi, Yumi, Roman-Lopes, Alexandre, Majewski, Steven R., Almeida, Andrés, Cunha, Katia, Smith, Verne V. |
| Publication Year: |
2023 |
| Collection: |
Astrophysics |
| Subject Terms: |
Astrophysics - Astrophysics of Galaxies |
| More Details: |
Stellar ages are critical for understanding the temporal evolution of a galaxy. We calculate the ages of over 6000 red giant branch stars in the Large Magellanic Cloud (LMC) observed with SDSS-IV / APOGEE-S. Ages are derived using multi-band photometry, spectroscopic parameters (T$_\text{eff}$, $\log{g}$, [Fe/H], and [$\alpha$/Fe]) and stellar isochrones and the assumption that the stars lie in a thin inclined plane to get accurate distances. The isochrone age and extinction are varied until a best match is found for the observed photometry. We perform validation using the APOKASC sample, which has asteroseismic masses and accurate ages, and find that our uncertainties are $\sim$20% and range from $\sim$1$-$3 Gyr for the calculated age values. Here we present the LMC age map as well as the age-radius relation and an accurate age-metallicity relation (AMR). The age map and age-radius relation reveal that recent star formation in the galaxy was more centrally located and that there is a slight dichotomy between the north and south with the northern fields being slightly younger. The northern fields that cover a known spiral arm have median ages of $\gtrsim$ 2 Gyr, which is the time when an interaction with the SMC is suggested to have happened. The AMR is mostly flat especially for older ages although recently (about 2.0-2.5 Gyr ago) there is an increase in the median [Fe/H]. Based on the time frame, this might also be attributed to the close interaction between the LMC and SMC.
Comment: 21 pages, 22 figures, submitted to MNRAS |
| Document Type: |
Working Paper |
| Access URL: |
http://arxiv.org/abs/2306.06348 |
| Accession Number: |
edsarx.2306.06348 |
| Database: |
arXiv |
