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The extended disc and halo of the Andromeda galaxy observed with Spitzer-IRAC

Rafiei Ravandi, Masoud and Barmby, Pauline and Ashby, Matthew L. N. and Laine, Seppo and Davidge, T. J. and Zhang, Jenna and Bianchi, Luciana and Babul, Arif and Chapman, S. C. (2016) The extended disc and halo of the Andromeda galaxy observed with Spitzer-IRAC. Monthly Notices of the Royal Astronomical Society, 459 (2). pp. 1403-1414. ISSN 0035-8711. doi:10.1093/mnras/stw652.

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We present the first results from an extended survey of the Andromeda galaxy (M31) using 41.1 h of observations by Spitzer-IRAC at 3.6 and 4.5 µm. This survey extends previous observations to the outer disc and halo, covering total lengths of 4°.4 and 6°.6 along the minor and major axes, respectively. We have produced surface brightness profiles by combining the integrated light from background-corrected maps with stellar counts from a new catalogue of point sources. Using auxiliary catalogues, we have carried out a statistical analysis in colour–magnitude space to discriminate M31 objects from foreground Milky Way stars and background galaxies. The catalogue includes 426 529 sources, of which 66 per cent have been assigned probability values to identify M31 objects with magnitude depths of [3.6] = 19.0 ± 0.2, [4.5] = 18.7 ± 0.2. We discuss applications of our data for constraining the stellar mass and characterizing point sources in the outer radii.

Item Type:Article
Related URLs:
URLURL TypeDescription Information Paper
Barmby, Pauline0000-0003-2767-0090
Ashby, Matthew L. N.0000-0002-3993-0745
Laine, Seppo0000-0003-1250-8314
Bianchi, Luciana0000-0001-7746-5461
Babul, Arif0000-0003-1746-9529
Additional Information:© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2016 March 14. Received 2016 March 14; in original form 2015 December 15. First published online March 20, 2016. MRR thanks Sahar Rahmani for technical support. We thank Steven Willner for providing fruitful comments on the initial manuscript; Stéphane Courteau for providing surface brightness profiles from Courteau et al. (2011); Alan W. McConnachie and the entire PAndAS collaboration for providing access to the PAndAS catalogue. This work is based on observations made with the Spitzer Space Telescope and has made use of the NASA/IPAC Infrared Science Archive, both operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Support for this work was provided by NASA and by a Discovery Grant from the Natural Science and Engineering Research Council, Canada. This research made use of NASA's Astrophysics Data System; MONTAGE, funded by the National Science Foundation under Grant Number ACI-1440620, and was previously funded by the National Aeronautics and Space Administration's Earth Science Technology Office, Computation Technologies Project, under Cooperative Agreement Number NCC5-626 between NASA and the California Institute of Technology; TOPCAT, an interactive graphical viewer and editor for tabular data (Taylor 2005); the facilities of the Canadian Astronomy Data Centre operated by the National Research Council of Canada with the support of the Canadian Space Agency; and Digitized Sky Survey, retrieved via Aladin (Bonnarel et al. 2000). The Digitized Sky Surveys were produced at the Space Telescope Science Institute under US Government grant NAG W-2166. The images of these surveys are based on photographic data obtained using the Oschin Schmidt Telescope on Palomar Mountain and the UK Schmidt Telescope. The plates were processed into the present compressed digital form with the permission of these institutions. Facilities: Spitzer Space Telescope (IRAC).
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Canadian Space Agency (CSA)UNSPECIFIED
Subject Keywords:galaxies: individual: M31 – galaxies: spiral – galaxies: stellar content – infrared: galaxies
Issue or Number:2
Record Number:CaltechAUTHORS:20160707-105225797
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Official Citation:Masoud Rafiei Ravandi, Pauline Barmby, Matthew L. N. Ashby, Seppo Laine, T. J. Davidge, Jenna Zhang, Luciana Bianchi, Arif Babul, and S. C. Chapman The extended disc and halo of the Andromeda galaxy observed with Spitzer-IRAC MNRAS (June 21, 2016) Vol. 459 1403-1414 doi:10.1093/mnras/stw652 first published online March 20, 2016
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:68890
Deposited By: Tony Diaz
Deposited On:07 Jul 2016 19:23
Last Modified:11 Nov 2021 04:06

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