J/MNRAS/440/3430 SDSS-2MASS-WISE stellar colour locus (Davenport+, 2014)
The SDSS-2MASS-WISE 10-dimensional stellar colour locus.
Davenport J.R.A., Ivezic Z., Becker A.C., Ruan J.J., Hunt-Walker N.M.,
Covey K.R., Lewis A.R., Alsayyad Y., Anderson L.M.
<Mon. Not. R. Astron. Soc., 440, 3430-3438 (2014)>
=2014MNRAS.440.3430D 2014MNRAS.440.3430D (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Photometry, SDSS ; Photometry, infrared ; Colors
Keywords: surveys - stars: fundamental parameters - stars: general -
dust, extinction
Abstract:
We present the fiducial main-sequence stellar locus traced by 10
photometric colours observed by Sloan Digital Sky Survey (SDSS), Two
Micron All Sky Survey (2MASS), and Wide-field Infrared Survey
Explorer (WISE). Median colours are determined using 1052 793 stars
with r-band extinction less than 0.125. We use this locus to measure
the dust extinction curve relative to the r band, which is consistent
with previous measurements in the SDSS and 2MASS bands. The WISE band
extinction coefficients are larger than predicted by standard
extinction models. Using 13 lines of sight, we find variations in the
extinction curve in H, Ks, and WISE bandpasses. Relative extinction
decreases towards Galactic anticentre, in agreement with prior
studies. Relative extinction increases with Galactic latitude, in
contrast to previous observations. This indicates a universal mid-IR
extinction law does not exist due to variations in dust grain size and
chemistry with Galactocentric position. A preliminary search for
outliers due to warm circumstellar dust is also presented, using stars
with high signal-to-noise ratio in the W3 band. We find 199 such
outliers, identified by excess emission in Ks-W3. Inspection of SDSS
images for these outliers reveals a large number of contaminants due
to nearby galaxies. Six sources appear to be genuine dust candidates,
yielding a fraction of systems with infrared excess of 0.12±0.05 per
cent.
Description:
Our data come from three surveys that differ greatly in their sky
coverage, photometric depth, and wavelength coverage.
The optical photometry for our study came from the SDSS Data Release 8
(DR8; Aihara et al. 2011ApJS..193...29A 2011ApJS..193...29A).
The mid-infrared photometry we used came from the latest AllWISE data
release (Cutir et al., 2013, Cat. II/328).
Astrometric calibration for WISE was achieved by matching sources to
the full-sky 2MASS point source catalog (Wright et al.
2010AJ....140.1868W 2010AJ....140.1868W).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 97 135 Optical and NIR colour locus as a function of
g-i colour bins
table2.dat 71 135 The mid-IR colour locus as a function of
g-i colour
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See also:
II/328 : AllWISE Data Release (Cutri+ 2013)
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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2- 5 F4.2 mag g-i g-i colour index
9- 13 I5 --- Nstar Number of stars in each bin
15- 19 F5.3 mag u-g u-g colour index
21- 25 F5.3 mag e_u-g rms uncertainty on u-g
27- 31 F5.3 mag g-r g-r colour index
33- 37 F5.3 mag e_g-r rms uncertainty on g-r
39- 43 F5.3 mag r-i r-i colour index
45- 49 F5.3 mag e_r-i rms uncertainty on r-i
50- 55 F6.3 mag i-z i-z colour index
57- 61 F5.3 mag e_i-z rms uncertainty on i-z
63- 67 F5.3 mag z-J z-J colour index
69- 73 F5.3 mag e_z-J rms uncertainty on z-J
75- 79 F5.3 mag J-H J-H colour index
81- 85 F5.3 mag e_J-H rms uncertainty on J-H
87- 91 F5.3 mag H-Ks H-Ks colour index
93- 97 F5.3 mag e_H-Ks rms uncertainty on H-Ks
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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4- 7 F4.2 mag g-i g-i colour index
10- 14 I5 --- Nstars Number of stars in each bin from the
primary sample
18- 22 F5.3 mag Ks-W1 Ks-W1 colour index
26- 30 F5.3 mag e_Ks-W1 rms uncertainty on Ks-W1
33- 38 F6.3 mag W1-W2 W1-W2 colour index
42- 46 F5.3 mag e_W1-W2 rms uncertainty on W1-W2
50- 52 I3 --- NStarsW3 Number of stars in each bin from the
W3-limited subsample
55- 61 F7.3 mag W2-W3 ?=-99 W2-W3 colour index
67- 71 F5.3 mag e_W2-W3 ?=0 rms uncertainty on W2-W3
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 22-May-2017