Stellar Metallicities from SkyMapper Photometry. II. Precise Photometric Metallicities of ∼280,000 Giant Stars with [Fe/H]
Name
Chiti_2021_ApJS_254_31.pdf
Description
Published version
Size
3.46 MB
Format
Adobe PDF
Checksum (MD5)
84c97dfe0b2dcaf2f6ebcdc4f25cea09
Author(s)
Chiti, Anirudh
Frebel, Anna
Mardini, Mohammad K
Daniel, Tatsuya W
Ou, Xiaowei
Uvarova, Anastasiia V
Date Issued
2021
Journal
The Astrophysical Journal Supplement Series
Publisher
American Astronomical Society
Citation
Chiti, Anirudh, Frebel, Anna, Mardini, Mohammad K, Daniel, Tatsuya W, Ou, Xiaowei et al. 2021. "Stellar Metallicities from SkyMapper Photometry. II. Precise Photometric Metallicities of ∼280,000 Giant Stars with [Fe/H]." The Astrophysical Journal Supplement Series, 254 (2).
Version
Final published version
Abstract
The Milky Way's metal-poor stars are nearby ancient objects that are used to study early chemical evolution and the assembly and structure of the Milky Way. Here we present reliable metallicities of ∼280,000 stars with −3.75 ≲ [Fe/H] ≲ −0.75 down to g = 17 derived using metallicity-sensitive photometry from the second data release of the SkyMapper Southern Survey. We use the dependency of the flux through the SkyMapper v filter on the strength of the Ca ii K absorption features, in tandem with SkyMapper u, g, i photometry, to derive photometric metallicities for these stars. We find that metallicities derived in this way compare well to metallicities derived in large-scale spectroscopic surveys, and we use such comparisons to calibrate and quantify systematics as a function of location, reddening, and color. We find good agreement with metallicities from the APOGEE, LAMOST, and GALAH surveys, based on a standard deviation of σ ∼ 0.25 dex of the residuals of our photometric metallicities with respect to metallicities from those surveys. We also compare our derived photometric metallicities to metallicities presented in a number of high-resolution spectroscopic studies to validate the low-metallicity end ([Fe/H] < −2.5) of our photometric metallicity determinations. In such comparisons, we find the metallicities of stars with photometric [Fe/H] < −2.5 in our catalog show no significant offset and a scatter of σ ∼ 0.31 dex level relative to those in high-resolution work when considering the cooler stars (g − i > 0.65) in our sample. We also present an expanded catalog containing photometric metallicities of ∼720,000 stars as a data table for further exploration of the metal-poor Milky Way.
MIT Department
Massachusetts Institute of Technology. Department of Physics
MIT Kavli Institute for Astrophysics and Space Research
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.3847/1538-4365/ABF73D
