Spectroscopic Redshifts to z > 2 for Optically Obscured Sources Discovered with the Spitzer Space Telescope

April 2005 • 2005ApJ...622L.105H

Authors • Houck, J. R. • Soifer, B. T. • Weedman, D. • Higdon, S. J. U. • Higdon, J. L. • Herter, T. • Brown, M. J. I. • Dey, A. • Jannuzi, B. T. • Le Floc'h, E. • Rieke, M. • Armus, L. • Charmandaris, V. • Brandl, B. R. • Teplitz, H. I.

Abstract • We have surveyed a field covering 9.0 deg² within the NOAO Deep Wide-Field Survey region in Bootes with the Multiband Imaging Photometer on the Spitzer Space Telescope (SST) to a limiting 24 μm flux density of 0.3 mJy. Thirty-one sources from this survey with F_24μm>0.75 mJy that are optically very faint (R>~24.5 mag) have been observed with the low-resolution modules of the Infrared Spectrograph on SST (IRS). Redshifts derived primarily from strong silicate absorption features are reported here for 17 of these sources; 10 of these are optically invisible (R>~26 mag), with no counterpart in B_W, R, or I. The observed redshifts for 16 sources are 1.7<z<2.8. These represent a newly discovered population of highly obscured sources at high redshift with extreme infrared-to-optical ratios. Using IRS spectra of local galaxies as templates, we find that a majority of the sources have mid-infrared spectral shapes most similar to ultraluminous infrared galaxies powered primarily by active galactic nuclei. Assuming that the same templates also apply at longer wavelengths, bolometric luminosities exceed 10¹³ L_solar.

Links

• PREPRINT http://arxiv.org/abs/astro-ph/0502216
• NED https://ned.ipac.caltech.edu/uri/NED::InRefcode/2005ApJ...622L.105H
• ELECTR https://doi.org/10.1086%2F429405
• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2005ApJ...622L.105H
• PDF https://iopscience.iop.org/article/10.1086/429405/pdf
• DATA https://irsa.ipac.caltech.edu/bibdata/2005/H/2005ApJ...622L.105H.html
• SPIRES http://inspirehep.net/search?p=find+eprint+astro-ph/0502216