Cold dust in (some) high-z supernova host galaxies
Abstract
We present deep submillimetre photometry for 14 galaxies at z = 0.5 that are hosts of Type la supernovae, with the aim of examining the evolution of dust mass and extinction in normal galaxies. We combine these results with our previous observations of 17 z ~ 0.5 SN1a hosts to look for any evolution in the dust content of normal galaxies between z = 0 and 0.5. The average observed-frame 850-µm flux of SN1a hosts in the full sample, excluding two bright individually detected objects, is 0.44 ± 0.22 mJy. This flux level is consistent with there being little or no evolution in the dust content, or optical extinction, of normal galaxies from z = 0 to 0.5. One galaxy, the host of SN1996cf, is detected individually, and we also present a deep Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) image for this object. It appears to be an edge-on disc system, similar to the submillimetre bright host of SN1997ey. We thus examine the dust properties of these and one other individually detected object. Flux ratios and limits of 450-850 µm suggest that the dust in the two brightest submillimetre sources, SN1996cf and SN1997ey, is cold, T ~ 20 K, implying that they contain a substantial mass of dust ~ 10^(9) M_⊙. The presence of two bright F_(850) > 7 mJy) submillimetre sources at z ~ 0.5 in a sample of ostensibly normal galaxies is surprising, and has important implications. It supports the idea that a substantial part of the cosmic infrared background (CIB) may be produced at z < 1, while also suggesting that 'foreground' objects such as these may be a significant 'contaminant' in submillimetre surveys. Finally, we examine the overall submillimetre luminosity distribution at z = 0.5 implied by our results, and conclude that either there is substantial evolution in the submillimetre luminosity function from z = 0 to 0.5, or our submillimetre-detected sources are somehow not representative of the bulk of galaxies at this redshift.
Additional Information
© 2005 Royal Astronomical Society. Accepted 2005 July 14. Received 2005 July 11; in original form 2005 June 7. Article first published online: 7 Sep 2005. The James Clerk Maxwell Telescope (JCMT) is operated by The Joint Astronomy Centre on behalf of the Particle Physics and Astronomy Research Council of the United Kingdom, the Netherlands Organization for Scientific Research and the National Research Council of Canada. DLC acknowledges funding from PPARC. JA gratefully acknowledges the support from the Science and Technology Foundation (FCT, Portugal) through the research grant POCTI-FNU-43805-2001. The authors would like to thank the staff at the JCMT for their usual excellent support work, and R. Kotak for useful discussions. The research described in this paper was carried out, in part, by the Jet Propulsion Laboratory, California Institute of Technology, and was sponsored by the National Aeronautics and Space Administration. This publication is also based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.Attached Files
Published - CLEmnras06.pdf
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Additional details
- Eprint ID
- 22537
- Resolver ID
- CaltechAUTHORS:20110228-090445474
- POCTI-FNU-43805-2001
- Fundação para a Ciência e a Tecnologia (FCT)
- NAS5-26555
- NASA
- Created
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2011-02-28Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field