J/AJ/147/76 Photometry of M giant candidates in the Milky Way (Bochanski+, 2014)
Hunting the most distant stars in the Milky Way: methods and initial results.
Bochanski J.J., Willman B., West A.A., Strader J., Chomiuk L.
<Astron. J., 147, 76 (2014)>
=2014AJ....147...76B 2014AJ....147...76B
ADC_Keywords: Milky Way ; Stars, M-type ; Stars, giant ; Photometry, SDSS ;
Photometry, infrared
Keywords: Galaxy: halo - Galaxy: stellar content - Galaxy: structure -
stars: late-type
Abstract:
We present a new catalog of 404 M giant candidates found in the UKIRT
Infrared Deep Sky Survey (UKIDSS). The 2400deg2 available in the
UKIDSS Large Area Survey Data Release 8 resolve M giants through a
volume four times larger than that of the entire Two Micron All Sky
Survey. Combining near-infrared photometry with optical photometry and
proper motions from the Sloan Digital Sky Survey yields an M giant
candidate catalog with less M dwarf and quasar contamination than
previous searches for similarly distant M giants. Extensive follow-up
spectroscopy of this sample will yield the first map of our Galaxy's
outermost reaches over a large area of sky. Our initial spectroscopic
follow-up of ∼30 bright candidates yielded the positive identification
of five M giants at distances ∼20-90kpc. Each of these confirmed M
giants have positions and velocities consistent with the Sagittarius
stream. The fainter M giant candidates in our sample have estimated
photometric distances ∼200kpc (assuming [Fe/H]=0.0), but require
further spectroscopic verification. The photometric distance estimates
extend beyond the Milky Way's virial radius, and increase by ∼50% for
each 0.5dex decrease in assumed [Fe/H]. Given the number of M giant
candidates, initial selection efficiency, and volume surveyed, we
loosely estimate that at least one additional Sagittarius-like
accretion event could have contributed to the hierarchical build-up of
the Milky Way's outer halo.
Description:
Using a combination of near-infrared and optical photometry and
spectroscopy from UKIDSS and SDSS, we have assembled a catalog of 404
M Giant candidates.
UKIDSS (Lawrence et al., 2012, cat. II/319) is a near-infrared
photometric survey being conducted at the 3.8m UK Infrared Telescope
(UKIRT). The survey employs the UKIRT Wide Field Camera, imaging the
sky with a zyJHK filter set.
The SDSS (Adelman-McCarthy et al., 2012, cat V/139) was an optical
photometric and spectroscopic survey of 14555deg2 conducted with the
2.5m telescope at the Apache Point Observatory. The camera contained
five camera columns, each corresponding to one filter in the ugriz
system.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 131 404 SDSS and UKIDSS photometry of M giant candidates
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See also:
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
J/AJ/143/128 : High-metallicity M giant candidates from SDSS (Palladino+, 2012)
http://surveys.roe.ac.uk/wsa/ : UKIDSS online data
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [ULAS]
6- 24 A19 --- ULAS M giant candidate identifier (1)
26- 34 F9.5 deg RAdeg Right Ascension in decimal degrees (J2000)
36- 43 F8.5 deg DEdeg Declination in decimal degrees (J2000)
45- 49 F5.2 mag umag SDSS u band magnitude
51- 54 F4.2 mag e_umag The 1σ error in umag
56- 60 F5.2 mag gmag SDSS g band magnitude
62- 65 F4.2 mag e_gmag The 1σ error in gmag
67- 71 F5.2 mag rmag SDSS r band magnitude
73- 76 F4.2 mag e_rmag The 1σ error in rmag
78- 82 F5.2 mag imag SDSS i band magnitude
84- 87 F4.2 mag e_imag The 1σ error in imag
89- 93 F5.2 mag zmag SDSS z band magnitude
95- 98 F4.2 mag e_zmag The 1σ error in zmag
100-104 F5.2 mag Jmag UKIDSS J band magnitude
106-109 F4.2 mag e_Jmag The 1σ error in Jmag
111-115 F5.2 mag Hmag UKIDSS H band magnitude
117-120 F4.2 mag e_Hmag The 1σ error in Hmag
122-126 F5.2 mag Kmag UKIDSS K band magnitude
128-131 F4.2 mag e_Kmag The 1σ error in Kmag
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Note (1): JHHMMSS.ss+DDMMSS.s format; from the UKIDSS-LAS catalog (DR9,
Lawrence et al., 2012, cat. II/319).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 10-Sep-2014