Lonsdale, Carol J. and Polletta, Maria del Carmen and Omont, Alain and Shupe, Dave and Berta, Stefano and Zylka, Robert and Siana, Brian and Lutz, Dieter and Farrah, Duncan and Smith, Harding E. and Lagache, Guilaine and De-Breuck, Carlos and Owen, Frazer and Beelen, Alexandre and Weedman, Dan and Franceschini, Alberto and Clements, Dave and Tacconi, Linda and Afonso-Luis, Alejandro and Pérez-Fournon, Ismael and Cox, Pierre and Bertoldi, Frank (2009) MAMBO 1.2 mm Observations of Luminous Starbursts at z ~ 2 in the SWIRE Fields. Astrophysical Journal, 692 (1). pp. 422-442. ISSN 0004-637X http://resolver.caltech.edu/CaltechAUTHORS:20090911-081110058
- Published Version
Restricted to Repository administrators only
See Usage Policy.
Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20090911-081110058
We report on-off pointed MAMBO observations at 1.2 mm of 61 Spitzer-selected star-forming galaxies from the Spitzer Wide Area Infrared Extragalactic Legacy survey (SWIRE). The sources are selected on the basis of bright 24 μm fluxes (f _(24μm) > 0.4 mJy) and of stellar dominated near-infrared spectral energy distributions in order to favor z ~ 2 starburst galaxies. The average 1.2 mm flux for the whole sample is 1.5 ± 0.2 mJy. Our analysis focuses on 29 sources in the Lockman Hole field where the average 1.2 mm flux (1.9 ± 0.3 mJy) is higher than in other fields (1.1 ± 0.2 mJy). The analysis of the multiwavelength spectral energy distributions indicates that these sources are starburst galaxies with far-infrared luminosities from 10^(12) to 10^(13.3)L_☉ , and stellar masses of ~0.2-6 × 10^(11)M_☉ . Compared to submillimeter selected galaxies (SMGs), the SWIRE-MAMBO sources are among those with the largest 24 μm/1.2 mm flux ratios. The origin of such large ratios is investigated by comparing the average mid-infrared spectra and the stacked far-infrared spectral energy distributions of the SWIRE-MAMBO sources and of SMGs. The mid-infrared spectra, available for a handful of sources, exhibit strong polycyclic aromatic hydrocarbon (PAH) features, and a warm dust continuum. The warm dust continuum contributes ~34% of the mid-infrared emission, and is likely associated with an AGN component. This contribution is consistent with what is found in SMGs. The large 24 μm/1.2 mm flux ratios are thus not due to AGN emission, but rather to enhanced PAH emission compared to SMGs. The analysis of the stacked far-infrared fluxes yields warmer dust temperatures than typically observed in SMGs. Our selection favors warm ultraluminous infrared sources at high-z, a class of objects that is rarely found in SMG samples. Indeed SMGs are not common among bright 24 μm sources (e.g., only about 20% of SMGs have f_(24 μm) > 0.4 mJy). Our sample is the largest Spitzer-selected sample detected at millimeter wavelengths currently available.
|Additional Information:||© 2009. The American Astronomical Society. Received 2007 December 10; accepted 2008 October 2; published 2009 February 19. We thank the referee for useful comments that improved the paper. C.J.L. and M.P. thank Bruce Elmegreen and Jakob Walcher for helpful discussion. We are grateful to Elisabetta Valiante for providing the average IRS spectrum of a sample of SMGs. M.P. acknowledges financial support from the Marie-Curie Fellowship grant MEIF-CT-2007-042111. This work is based on observations made with the IRAM 30m Telescope and the Spitzer Space Telescope. The IRAM 30m Telescope is funded by the Centre National de la Recherche Scientifique (France), the Max-Planck Gesellschaft (Germany), and the Instituto Geografico Nacional (Spain). The Spitzer Space Telescope is operated by the Jet Propulsion Laboratory, California Institute of Technology under NASA contract 1407. Support for thiswork, part of the Spitzer Space Telescope Legacy Science Program, was provided by NASA through an award issued by the Jet Propulsion Laboratory, California Institute of Technology under NASA contract 1407. We thank the IRAM staff for their support during the observations, and E. Kreysa and his group for providing the MAMBO bolometer array. This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.|
|Subject Keywords:||cosmology: observations; galaxies: formation; galaxies: high-redshift; galaxies: starburst; infrared: galaxies; submillimeter|
|Official Citation:||MAMBO 1.2 mm Observations of Luminous Starbursts at z ~ 2 in the SWIRE Fields Carol J. Lonsdale, Maria del Carmen Polletta, Alain Omont, Dave Shupe, Stefano Berta, Robert Zylka, Brian Siana, Dieter Lutz, Duncan Farrah, Harding E. Smith, Guilaine Lagache, Carlos De Breuck, Frazer Owen, Alexandre Beelen, Dan Weedman, Alberto Franceschini, Dave Clements, Linda Tacconi, Alejandro Afonso-Luis, Ismael Pérez-Fournon, Pierre Cox, and Frank Bertoldi 2009 ApJ 692 422-442 doi: 10.1088/0004-637X/692/1/422|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Ruth Sustaita|
|Deposited On:||15 Sep 2009 17:21|
|Last Modified:||26 Dec 2012 11:21|
Repository Staff Only: item control page