Mid-Infrared Selection of Brown Dwarfs and High-Redshift Quasars

Abstract

We discuss color selection of rare objects in a wide-field, multiband survey spanning from the optical to the mid-infrared. Simple color criteria simultaneously identify and distinguish two of the most sought after astrophysical sources: the coolest brown dwarfs and the most distant quasars. We present spectroscopically-confirmed examples of each class identified in the IRAC Shallow Survey of the Bootes field of the NOAO Deep Wide-Field Survey. ISS J142950.9+333012 is a T4.5 brown dwarf at a distance of approximately 42 pc, and ISS J142738.5+331242 is a radio-loud quasar at redshift z=6.12. Our selection criteria identify a total of four candidates over 8 square degrees of the Bootes field. The other two candidates are both confirmed 5.5<z<6 quasars, previously reported by Cool et al. (2006). We discuss the implications of these discoveries and conclude that there are excellent prospects for extending such searches to cooler brown dwarfs and higher redshift quasars.

19 pages, 7 figures; submitted to the Astrophysical Journal

References in corpus (11)

• Spectral Energy Distributions and Multiwavelength Selection of Type 1 Quasars
• Discovery of Two T Dwarf Companions with the Spitzer Space Telescope
• Spitzer/IRAC Photometry of M, L, and T Dwarfs
• SDSS J1534+1615AB: A Novel T Dwarf Binary Found with Keck Laser Guide Star Adaptive Optics and the Potential Role of Binarity in the L/T Transition
• Photometric Redshifts in the IRAC Shallow Survey
• The Stellar Masses and Star Formation Histories of Galaxies at z ~ 6: Constraints from Spitzer Observations in the Great Observatories Origins Deep Survey
• Probing the Evolution of IR Properties of z~6 Quasars: Spitzer Observations
• The Stellar Mass Density at z~6 from Spitzer Imaging of i-drop Galaxies
• Discovery of a z=6.1 Radio-Loud Quasar in the NDWFS
• The Discovery of Three New z>5 Quasars in the AGN and Galaxy Evolution Survey
• zBootes : z-band Photometry in the NOAO Deep Wide-Field Survey Bootes Field

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