J/AJ/134/2398 Stellar SEDs in SDSS and 2MASS filters (Covey+, 2007)
Stellar SEDs from 0.3 to 2.5 µm: tracing the stellar locus and searching for
color outliers in the SDSS and 2MASS.
Covey K.R., Ivezic Z., Schlegel D., Finkbeiner D., Padmanabhan N.,
Lupton R.H., Agueros M.A., Bochanski J.J., Hawley S.L., West A.A., Seth A.,
Kimball A., Gogarten S.M., Claire M., Haggard D., Kaib N., Schneider D.P.,
Sesar B.
<Astron. J., 134, 2398-2417 (2007)>
=2007AJ....134.2398C 2007AJ....134.2398C
ADC_Keywords: Photometry, SDSS ; Photometry, infrared ; Energy distributions
Keywords: Galaxy: stellar content - infrared: stars - stars: early-type -
stars: late-type - surveys
Abstract:
The Sloan Digital Sky Survey (SDSS) and Two Micron All Sky Survey
(2MASS) are rich resources for studying stellar astrophysics and the
structure and formation history of the Galaxy. As new surveys and
instruments adopt similar filter sets, it is increasingly important to
understand the properties of the ugrizJHKs stellar locus, both to
inform studies of "normal" main-sequence stars and enable robust
searches for point sources with unusual colors. Using a sample of
∼600000 point sources detected by SDSS and 2MASS, we tabulate the
position and width of the ugrizJHKs stellar locus as a function of g-i
color, and provide accurate polynomial fits. We map the Morgan-Keenan
spectral type sequence to the median stellar locus by using synthetic
photometry of spectral standards and by analyzing 3000 SDSS stellar
spectra with a custom spectral typing pipeline, described in the
Appendix to this paper. We develop an algorithm to calculate a point
source's minimum separation from the stellar locus in a
seven-dimensional color space, and use it to robustly identify objects
with unusual colors, as well as spurious SDSS/2MASS matches.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 80 201 Locus colors as a function of g-i color
table3.dat 57 86 Synthetic SDSS/2MASS photometry of Pickles
(1998, Cat. J/PASP/110/863) solar
metallicity standards
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/294 : SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
J/PASP/110/863 : A Stellar Spectral Flux Library: 1150-25000A (Pickles 1998)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 F4.2 mag g-i The (g-i) color index
6- 9 I4 --- Nstars Number of stars
11- 14 F4.2 mag u-g The (u-g) color index
16- 19 F4.2 mag e_u-g The 1σ error in u-g
21- 24 F4.2 mag g-r The (g-r) color index
26- 29 F4.2 mag e_g-r The 1σ error in g-r
31- 34 F4.2 mag r-i The (r-i) color index
36- 39 F4.2 mag e_r-i The 1σ error in r-i
41- 45 F5.2 mag i-z The (i-z) color index
47- 50 F4.2 mag e_i-z The 1σ error in i-z
52- 55 F4.2 mag z-J The (z-J) color index
57- 60 F4.2 mag e_z-J The 1σ error in z-J
62- 65 F4.2 mag J-H The (J-H) color index
67- 70 F4.2 mag e_J-H The 1σ error in J-H
72- 75 F4.2 mag H-Ks The (H-Ks) color index
77- 80 F4.2 mag e_H-Ks The 1σ error in H-Ks
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- SpType MK spectral type
6- 8 A3 --- LClass Luminosity class
10- 14 F5.2 mag u-g The (u-g) color index
16- 20 F5.2 mag g-r The (g-r) color index
22- 26 F5.2 mag r-i The (r-i) color index
28- 32 F5.2 mag i-z The (i-z) color index
34- 38 F5.2 mag z-J The (z-J) color index
40- 44 F5.2 mag J-H The (J-H) color index
46- 50 F5.2 mag H-Ks The (H-Ks) color index
52- 57 F6.2 mag JMAG Absolute J band magnitude
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 13-Feb-2010