2006/09/01 by Alejo Martínez‐Sansigre, Alejo Martinez-Sansigre, Steve Rawlings +6 · 3 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Cosmic microwave background #Emission spectrum #Galaxies: Formation, Evolution, Phenomena #Galaxy #Microwave #Optics #Physics #Population #Quasar #Radio Astronomy Observations and Technology #Radio spectrum #Redshift #Spectral index #Spectral line #astro-ph
paper · pdf · doi:10.1111/j.1745-3933.2006.00247.x
published as Mon.Not.Roy.Astron.Soc.Lett. 373 (2006) L80-L84 · 6 pages, 2 colour figures, submitted to MNRAS
arxiv created 2006/09/01 · openalex publication_date 2006/10/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract We present multi-frequency radio observations of a sample of z∼ 2 obscured (type 2) quasars in the Spitzer extragalactic First Look Survey area. We combine the public data at 1.4 GHz, used in the selection of these sources, with new observations at 610 MHz (Giant Meterwave Radio Telescope) and at 4.9 GHz (Very Large Array). We find that the sample includes sources with steep, flat and gigahertz-peaked spectra. There are no strong correlations between the presence or absence of emission lines in the optical spectra and the radio spectral properties of the sample. However, there are no secure flat-spectrum type 2 quasars with narrow emission lines which would be problematic for unified schemes. Most of the population have straight radio spectra with spectral index α∼ 1 as is expected for developed, potentially Fanaroff–Riley type I-like jets in which continuous injection of relativistic electrons is accompanied by inverse Compton losses against the cosmic microwave background.