Rest-frame optical and far-infrared observations of extremely bright Lyman-break galaxy candidates at z∼ 2.5 |
| |
| Authors: | R J Ivison Ian Smail Misty Bentz J A Stevens K Menéndez-Delmestre S C Chapman A W Blain |
| |
| Institution: | UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ;Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ;Institute for Computational Cosmology, University of Durham, South Road, Durham DH1 3LE;Department of Astronomy, The Ohio State University, 140 W. 18th Ave, Columbus, OH 43210-1173, USA;Centre for Astrophysics Research, Science and Technology Research Centre, University of Hertfordshire, College Lane, Hatfield AL10 9AB;Department of Astronomy, California Institute of Technology, MS 320-47, Pasadena, CA 91125, USA |
| |
| Abstract: | We have investigated the rest-frame optical and far-infrared properties of a sample of extremely bright candidate Lyman-break galaxies (LBGs) identified in the Sloan Digital Sky Survey. Their high ultraviolet luminosities and lack of strong ultraviolet emission lines are suggestive of massive starbursts, although it is possible that they are more typical luminosity LBGs which have been highly magnified by strong gravitational lensing. Alternatively, they may be an unusual class of weak-lined quasars. If the ultraviolet and submillimetre (submm) properties of these objects mirror those of less luminous, starburst LBGs, then they should have detectable rest-frame far-infrared emission. However, our submm photometry fails to detect such emission, indicating that these systems are not merely scaled-up (either intrinsically or as a result of lensing) examples of typical LBGs. In addition we have searched for the morphological signatures of strong lensing, using high-resolution, near-infrared imaging, but we find none. Instead, near-infrared spectroscopy reveals that these systems are, in fact, a rare class of broad absorption line quasars. |
| |
| Keywords: | galaxies: active galaxies: evolution galaxies: formation quasars: general |
|
|
