Gigahertz-peaked spectrum (GPS) galaxies and quasars |
| |
| Authors: | Email author" target="_blank">M?G?MingalievEmail author Yu?V?Sotnikova T?V?Mufakharov A?K?Erkenov R?Yu?Udovitskiy |
| |
| Institution: | 1.Special Astrophysical Observatory,Russian Academy of Sciences,Nizhnii Arkhyz,Russia;2.Kazan (Volga Region) Federal University,Kazan,Russia |
| |
| Abstract: | The results of a comprehensive analysis of continuous radio spectra of a sample of Gigahertz-Peaked Spectrum (GPS) sources are reported. The sources are selected from a flux-density-complete sample (S ν ≥ 200 mJy at 4.8 or 5 GHz) using multifrequency measurements of the RATAN-600 radio telescope and data from the CATS astrophysical catalogs support system. The analysis revealed a very small number (1–2%) of “classical” GPS objects, which is significantly less than the expected fraction of 10%. GPS galaxies are found to have narrower and steeper radio spectra than quasars. The low-frequency part of the spectrum is seen to become steeper with increasing redshift. Galaxies and quasars at the same z have comparable angular sizes, whereas their luminosities may differ by one order of magnitude. At large redshifts there is a deficit of objects with low (several GHZ) peak frequencies. The number of GPS galaxies decreases sharply with redshift, and most of them are found at z between 0.01 and 1.81. GPS quasars are found at large redshifts, from 0.11 to 3.99. A quarter of the sample consists of blazars whose spectra may temporarily have a convex shape when the object is in active state. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
