Spitzer/Infrared Array Camera near-infrared features in the outer parts of S^4G galaxies



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Gil de Paz, Armando and otros, ... (2014) Spitzer/Infrared Array Camera near-infrared features in the outer parts of S^4G galaxies. Monthly notices of the Royal Astronomical Society, 444 (4). pp. 3015-3039. ISSN 0035-8711

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Official URL: http://dx.doi.org/10.1093/mnras/stu1642


We present a catalogue and images of visually detected features, such as asymmetries, extensions, warps, shells, tidal tails, polar rings, and obvious signs of mergers or interactions, in the faint outer regions (at and outside of R_25) of nearby galaxies. This catalogue can be used in future quantitative studies that examine galaxy evolution due to internal and external factors. We are able to reliably detect outer region features down to a brightness level of 0.03 MJy sr^−1 pixel^−1 at 3.6 μm in the Spitzer Survey of Stellar Structure in Galaxies (S^4G). We also tabulate companion galaxies. We find asymmetries in the outer isophotes in 22 ± 1 per cent of the sample. The asymmetry fraction does not correlate with galaxy classification as an interacting galaxy or merger remnant, or with the presence of companions. We also compare the detected features to similar features in galaxies taken from cosmological zoom re-simulations. The simulated images have a higher fraction (33 per cent) of outer disc asymmetries, which may be due to selection effects and an uncertain star formation threshold in the models. The asymmetries may have either an internal (e.g. lopsidedness due to dark halo asymmetry) or external origin.

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© 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Artículo firmado por 29 autores. We thank Ramin Skibba for helpful comments on a draft of this paper. We also thank Carrie Bridge for discussions on the merger rate. We acknowledge the helpful discussion with Chris Lintott about biases in classification. We acknowledge financial support to the DAGAL network from the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7/2007-2013/under REA grant agreement number PITN-GA-2011-289313. This work was cofunded under the Marie Curie Actions of the European Commission (FP7-COFUND). We also gratefully acknowledge support from NASA JPL/Spitzer grant RSA 1374189 provided for the S^4G project. EA and AB thank the CNES for support. KS, J-C M-M, TK, and TM acknowledge support from the National Radio Astronomy Observatory, which is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. The authors thank the entire S^4G team for their efforts in this project. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech. We are grateful to the dedicated staff at the Spitzer Science Center for their help and support in planning and execution of this Exploration Science program. This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by JPL, Caltech, under contract with NASA.

Uncontrolled Keywords:Digital-sky-survey; Artificial neural-networks; Polar-ring galaxies; Edge-on galaxies; Stellar structure; Spitzer survey; Morphological classification; Mpiral galaxies; Disk galaxies; Mu-m
Subjects:Sciences > Physics > Astrophysics
Sciences > Physics > Astronomy
ID Code:36082
Deposited On:02 Mar 2016 15:24
Last Modified:10 Dec 2018 15:05

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