FIRST-2Mass Sources below the APM Detection Threshold: A Population of Highly Reddened Quasars
We have constructed a sample of bright near-infrared sources that are detected at radio wavelengths but undetected on the first-generation Palomar Observatory Sky Survey (POSSI) plates in order to search for a population of dust-obscured quasars. Optical and infrared spectroscopic follow-up of the s...
Gespeichert in:
Veröffentlicht in: | The Astrophysical journal 2004-05, Vol.607 (1), p.60-75 |
---|---|
Hauptverfasser: | , , , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext bestellen |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | We have constructed a sample of bright near-infrared sources that are detected at radio wavelengths but undetected on the first-generation Palomar Observatory Sky Survey (POSSI) plates in order to search for a population of dust-obscured quasars. Optical and infrared spectroscopic follow-up of the sample has led to the discovery of 17 heavily reddened quasars (B-K > 6.5), 14 of which are reported here for the first time. This has allowed us to define a region in the R-K, J-K color plane in which 50% of the radio-selected objects are highly reddened quasars. We compare the surface density of this previously overlooked population to that of ultraviolet-excess radio-selected quasars, finding that they make up [approx]20% of the total quasar population for K ~ 15.5. |
---|---|
ISSN: | 0004-637X 1538-4357 |
DOI: | 10.1086/383305 |