نتایج جستجو برای: radio galaxies
تعداد نتایج: 141170 فیلتر نتایج به سال:
Recent Spitzer observations have revealed a substantial population of z∼ 2 ULIRGs with deep silicate absorption (τ9.7> 1). This paper reports a 20cm radio study of such a sample to elucidate their physical nature. We discover that a substantial fraction (40%) of deep silicate absorption ULIRGs at z∼ 2 are moderately radio-loud with L1.4GHz=10 25 – 10WHz. This is in strong contrast with z < ∼ 1 ...
We present evidence for a significant overdensity of red galaxies, as much as a factor of 14 over comparable field samples, in the field of the z = 1.47 radio galaxy B3 0003+387. The colors and luminosities of the brightest red galaxies are consistent with their being at z > 0.8. The radio galaxy and one of the red galaxies are separated by 5 and show some evidence of a possible interaction. Ho...
We derived the black hole fundamental plane relationship among the 1.4GHz radio luminosity (Lr), 0.1-2.4keV X-ray luminosity (LX), and black hole mass (M) from a uniform broad line SDSS AGN sample including both radio loud and radio quiet X-ray emitting sources. We found in our sample that the fundamental plane relation has a very weak dependence on the black hole mass, and a tight correlation ...
The bolometric luminosities and black hole (BH) masses are estimated by various methods for a sample of young radio galaxies with known ages. We find that the ages are positively correlated with the bolometric luminosities in these young radio galaxies, which is consistent with theoretical prediction based on radiation pressure instability of accretion disk in Czerny et al. The ages of young ra...
Predictions of the number of faint polarised radio sources that can be detected by SKA pathfinder telescopes and the SKA depend on the polarisation properties of radio sources with a total flux density around 1 mJy. Total intensity source counts suggest a transition in the dominant population from AGN to galaxies around this flux density, and the properties of brighter radio sources may not be ...
With the aim of exploring the properties of the class of FR 0 radio galaxies, we selected a sample of 108 compact radio sources, called FR0CAT, by combining observations from the NVSS, FIRST, and SDSS surveys. We included in the catalog sources with redshift ≤ 0.05, with a radio size . 5 kpc, and with an optical spectrum characteristic of low-excitation galaxies. Their radio luminosities at 1.4...
The emergence of a new population of radio galaxies at mJy and sub-mJy levels is responsible for the change in the slope of the radio source counts. This population seems to include both star forming galaxies and classical (AGN-powered) radio sources, but the relative importance of the two classes is still debated. We present results from the ATESP radio survey and its optical follow-up and sho...
In an earlier paper we presented nuclear X-ray flux densities, measured with ROSAT, for the B2 bright sample of nearby low-luminosity radio galaxies. In this paper we construct a nuclear X-ray luminosity function for the B2 radio galaxies, and discuss the consequences of our results for models in which such radio galaxies are the parent population of BL Lac objects. Based on our observations of...
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