J/ApJS/254/31 Photometric metallicities of stars in SkyMapper DR2 (Chiti+, 2021)
Stellar metallicities from SkyMapper photometry.
II. Precise photometric metallicities of ∼280000 giant stars with [Fe/H]<-0.75
in the Milky Way.
Chiti A., Frebel A., Mardini M.K., Daniel T.W., Ou X., Uvarova A.V.
<Astrophys. J. Suppl. Ser., 254, 31 (2021)>
=2021ApJS..254...31C 2021ApJS..254...31C
ADC_Keywords: Abundances, [Fe/H]; Photometry, VRI; Milky Way; Surveys
Keywords: Population II stars ; Milky Way Galaxy
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
∼280000 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 CaII 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∼0.25dex 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∼0.31dex 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 ∼720000 stars as a data table
for further exploration of the metal-poor Milky Way.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 66 728712 Photometric metallicities of stars in SkyMapper DR2
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See also:
II/358 : SkyMapper Southern Sky Survey. DR1.1 (Wolf+, 2018)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
J/AJ/90/2089 : Stars of very low metal abundance. I (Beers+, 1985)
J/AJ/103/1987 : Stars of very low metal abundance (Beers+ 1992)
J/A+A/439/129 : HERES II. Spectroscopic analysis (Barklem+, 2005)
J/ApJ/652/1585 : Bright metal-poor stars from HES survey (Frebel+, 2006)
J/A+A/484/721 : HES survey. IV. Candidate metal-poor stars (Christlieb+, 2008)
J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)
J/ApJ/762/26 : Most metal-poor stars. II. Galactic halo stars (Yong+, 2013)
J/ApJS/210/23 : Line intensities in CN transitions (Brooke+, 2014)
J/A+A/571/A47 : Extensive linelist of CH in atmospheres (Masseron+, 2014)
J/ApJ/797/21 : Carbon-enhanced metal-poor stars (Placco+, 2014)
J/ApJS/211/5 : Improved line data for the Swan system 12C13C (Ram+, 2014)
J/ApJS/214/26 : Line lists for CN isotopes transitions (Sneden+, 2014)
J/ApJ/807/171 : SkyMapper Survey metal-poor star spectrosc. (Jacobson+, 2015)
J/AJ/151/144 : ASPCAP weights for APOGEE chemical elements (Garcia+, 2016)
J/ApJ/847/142 : Ultra-metal-poor stars LTE & NLTE abund. (Ezzeddine+, 2017)
J/ApJS/238/16 : LAMOST-DR3 very metal-poor star catalog (Li+, 2018)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
12- 21 F10.6 deg DEdeg Declination in decimal degrees (J2000)
23- 27 F5.2 mag gmag [8.88/17] De-reddened g band magnitude
29- 33 F5.2 mag imag [8.48/16.6] De-reddened i band magnitude
35- 39 F5.2 [Sun] [Fe/H] [-3.8/-0.6] Metallicity
41- 44 F4.2 [Sun] e_[Fe/H] [0.16/0.8] Uncertainty in [Fe/H]
46- 64 I19 --- Gaia ? Gaia EDR3 source identifier
66 I1 --- Flag [0/1] Metal-rich or MS interloper flag
(1=metal-rich) (1)
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Note (1):
1 = satisfies one or more metal-rich interloper criteria (446,360 occurrences),
see Section 2.4.
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History:
From electronic version of the journal
References:
Chiti et al. Paper I. 2020ApJ...891....8C 2020ApJ...891....8C
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 19-Aug-2021