A Deep, Unbiased, Spitzer Spectroscopic Survey
Abstract
We carried out an unbiased, spectroscopic survey using the low resolution module of the infrared spectrograph (IRS) on board Spitzer targetting a 2 square arcminute region in the GOODS-North field. IRS was used in spectral mapping mode completly covering the target area, stepping by 5 arcsec in each direction between integrations. About 60 sources were detected in 46 hours, integrating for 5 hours of effective on-source time per pixel. We extracted a spectrum for 48 of them, and IRS redshifts have been determined using a cross-correlation technique for 50% of the spectra ranging from z 0.2 to z 2, with a peak at redshift 0.95. Most of the sources were detected at 5 sigma down to a 24 μm flux of 80 μJy with some detections being as faint as 30 μJy at 24 μm. About 75% of the sources for which we have a redshift show PAH emission. Another aim of this survey was to search for a new class of objects with very weak continuum but showing high or very-high line-to-continuum ratios. We have detected one candidate that fits this description at z 2.
- Publication:
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American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AAS...211.5217B