J/ApJ/714/663 Stellar density map of the Milky Way (de Jong+, 2010)
Mapping the stellar structure of the Milky Way thick disk and halo using
SEGUE photometry.
de Jong J.T.A., Yanny B., Rix H.-W., Dolphin A.E., Martin N.F., Beers T.C.
<Astrophys. J., 714, 663-674 (2010)>
=2010ApJ...714..663D 2010ApJ...714..663D
ADC_Keywords: Milky Way ; Stars, halo ; Stellar distribution
Keywords: Galaxy: disk - Galaxy: halo - Galaxy: structure - stars: statistics
Abstract:
We map the stellar structure of the Galactic thick disk and halo by
applying color-magnitude diagram (CMD) fitting to photometric data
from the Sloan Extension for Galactic Understanding and Exploration
(SEGUE) survey. The SEGUE imaging scans allow, for the first time, a
comprehensive analysis of Milky Way structure at both high and low
latitudes using uniform Sloan Digital Sky Survey photometry.
Incorporating photometry of all relevant stars simultaneously, CMD
fitting bypasses the need to choose single tracer populations. Using
old stellar populations of differing metallicities as templates, we
obtain a sparse three-dimensional map of the stellar mass distribution
at |Z|>1kpc. Fitting a smooth Milky Way model comprising exponential
thin and thick disks and an axisymmetric power-law halo allows us to
constrain the structural parameters of the thick disk and halo. The
thick-disk scale height and length are well constrained at
0.75±0.07kpc and 4.1±0.4kpc, respectively.
Description:
In this paper, we derive a new map of the stellar distribution in the
Milky Way, in order to study the large-scale structure of the thick
disk and stellar halo. Though covering only the northern celestial
hemisphere, and that only sparsely, this map covers both high and low
latitudes and uses rigorously derived stellar distances. This map is
based on one of the constituent projects of the extended SDSS survey
(SDSS II), SEGUE (Sloan Extension for Galactic Understanding and
Exploration; Yanny et al. 2009, Cat. J/AJ/137/4377), which is an
imaging and spectroscopic survey aimed at the study of the Milky Way
and its stellar populations. As part of the SEGUE survey, ten 2.5°
wide scans, crossing the Galactic plane at fixed longitudes, were
imaged in five passbands (u, g, r, i, and z).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 94 25476 Stellar density maps
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
J/A+A/534/A136 : Halo red giants from the SEGUE survey (Martell+, 2011)
J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)
J/AJ/136/2070 : SEGUE stellar parameter pipeline. III. (Allende Prieto+, 2008)
J/ApJ/678/851 : RR Lyrae survey in the Galactic Halo (Keller+, 2008)
J/AJ/135/564 : Photometry and spectroscopy of BHB candidates (Brown+, 2008)
J/AJ/126/1362 : Century Survey Galactic Halo Project. I. (Brown+, 2003)
J/other/Sci/292.698 : Candidate halo dark matter (Oppenheimer+, 2001)
J/A+A/326/751 : Chemical composition of halo and disk stars (Nissen+, 1997)
J/AJ/87/1515 : UBV photometry of AB stars in halo (Pier, 1982)
http://www.sdss.org/segue : SEGUE home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 F5.1 deg GLON Galactic longitude
7- 11 F5.1 deg GLAT Galactic latitude
13- 16 F4.1 mag m-M Distance modulus
18- 29 E12.6 Msun/kpc3 rho1 The [Fe/H]=-2.2 model stellar density (1)
31- 42 E12.6 Msun/kpc3 e_rho1 The 1σ error in rho1
44- 55 E12.6 Msun/kpc3 rho2 The [Fe/H]=-1.3 model stellar density (1)
57- 68 E12.6 Msun/kpc3 e_rho2 The 1σ error in rho2
70- 81 E12.6 Msun/kpc3 rho3 The [Fe/H]=-0.7 model stellar density (1)
83- 94 E12.6 Msun/kpc3 e_rho3 The 1σ error in rho3
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Note (1): The densities in this table correspond to the Salpeter IMF
(Salpeter 1955ApJ...121..161S 1955ApJ...121..161S) used by the MATCH software and are in
solar masses per cubic kiloparsec, unlike the densities quoted in the
text of the paper, which are corrected for a Kroupa IMF (Kroupa et al.
1993MNRAS.262..545K 1993MNRAS.262..545K) and in solar masses per cubic parsec.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 16-Apr-2012