TY - JOUR
T1 - Point sources from a Spitzer IRAC survey of the galactic center
AU - Ramírez, Solange V.
AU - Arendt, Richard G.
AU - Sellgren, Kris
AU - Stolovy, Susan R.
AU - Cotera, Angela
AU - Smith, Howard A.
AU - Yusef-Zadeh, Farhad
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2008/3
Y1 - 2008/3
N2 - We have obtained Spitzer IRAC observations of the central 2.0° × 1.4° (∼280 × 200pc)of the Galaxy at3.6-8.0μm. A point-source catalog of 1,065,565 objects is presented. The catalog includes magnitudes for the point sources at 3.6,4.5,5.8, and 8.0 μm, as well as JHKs photometry from Two Micron All Sky Survey (2MASS). The point-source catalog is confusion limited with average limits of 12.4, 12.1, 11.7, and 11.2 mag for [3.6], [4.5], [5.8], and [8.0], respectively. We find that the confusion limits are spatially variable because of stellar surface density, background surface brightness level, and extinction variations across the survey region. The overall distribution of point-source density with Galactic latitude and longitude is essentially constant, but structure does appear when sources of different magnitude ranges are selected. Bright stars show a steep decreasing gradient with Galactic latitude and a slow decreasing gradient with Galactic longitude, with a peak at the position of the Galactic center. From IRAC color-magnitude and color-color diagrams, we conclude that most of the point sources in our catalog have IRAC magnitudes and colors characteristic of red giant and asymptotic giant branch (AGB) stars.
AB - We have obtained Spitzer IRAC observations of the central 2.0° × 1.4° (∼280 × 200pc)of the Galaxy at3.6-8.0μm. A point-source catalog of 1,065,565 objects is presented. The catalog includes magnitudes for the point sources at 3.6,4.5,5.8, and 8.0 μm, as well as JHKs photometry from Two Micron All Sky Survey (2MASS). The point-source catalog is confusion limited with average limits of 12.4, 12.1, 11.7, and 11.2 mag for [3.6], [4.5], [5.8], and [8.0], respectively. We find that the confusion limits are spatially variable because of stellar surface density, background surface brightness level, and extinction variations across the survey region. The overall distribution of point-source density with Galactic latitude and longitude is essentially constant, but structure does appear when sources of different magnitude ranges are selected. Bright stars show a steep decreasing gradient with Galactic latitude and a slow decreasing gradient with Galactic longitude, with a peak at the position of the Galactic center. From IRAC color-magnitude and color-color diagrams, we conclude that most of the point sources in our catalog have IRAC magnitudes and colors characteristic of red giant and asymptotic giant branch (AGB) stars.
KW - Galaxy: center
KW - Stars: late-type
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U2 - 10.1086/524015
DO - 10.1086/524015
M3 - Article
AN - SCOPUS:42649089085
VL - 175
SP - 147
EP - 164
JO - Astrophysical Journal, Supplement Series
JF - Astrophysical Journal, Supplement Series
SN - 0067-0049
IS - 1
ER -