相关论文: Linking radio to infrared: a radio source count mo…

We determine the radio and optical luminosity evolutions and the true distribution of the radio loudness parameter R, defined as the ratio of the radio to optical luminosity, for a set of more than 5000 quasars combining SDSS optical and…

We calculate simultaneously the radio and optical luminosity evolutions of quasars, and the distribution in radio loudness R defined as the ratio of radio and optical luminosities, using a flux limited data set containing 636 quasars with…

Current wide-area radio surveys are dominated by active galactic nuclei, yet many of these sources have no identified optical counterparts. Here we investigate whether one can constrain the nature and properties of these sources, using…

The quasar sample selected by cross-correlating the FIRST and the 2dF Quasar Redshift Surveys allows us to explore, for the first time, the faint end of the radio and optical luminosity functions up to z = 2.2. We find indications (~3…

We investigate the radio-far infrared (FIR) correlation for a sample of $28$ bright high-redshift ($1 \lesssim z \lesssim 4$) star-forming galaxies selected in the FIR from the Herschel-ATLAS fields as candidates to be strongly…

Using data obtained as part of the {\it Spitzer} Infrared Nearby Galaxies Survey (SINGS; Kennicutt et al. 2003) and WSRT-SINGS radio continuum survey (Braun et al. 2006), we study the effects of star-formation activity on the far-infrared…

We have constructed a sample of radio-loud and radio-quiet quasars from the Faint Im- ages Radio Sky at Twenty-one centimetres (FIRST) and the Sloan Digital Sky Survey Data Release 7 (SDSS DR7), over the H-ATLAS Phase 1 Area (9h, 12h and…

Recent work on red and blue quasi-stellar objects (QSOs) has identified peculiar number distributions as a function of radio loudness that we explore and attempt to explain from the perspective of a picture in which a subset of the…

We present a detailed analysis of a sample of radio-detected quasars, obtained by matching together objects from the FIRST and 2dF Quasar Redshift Surveys. The dataset consists of 113 sources, spanning a redshift range 0.3 < z < 2.2, with…

We present a new approach to tackle the issue of radio loudness in quasars. We constrain a (simple) prescription for the intrinsic distribution of radio-to-optical ratios by comparing properties of Monte Carlo simulated samples with those…

I have assembled a diverse sample of galaxies from the literature with far-ultraviolet (FUV), optical, infrared (IR) and radio luminosities to explore the calibration of radio-derived and IR-derived star formation (SF) rates, and the origin…

This paper presents the first high-resolution and high-sensitivity study of the radio properties of optically selected type~2 quasars. We used the Very Large Array at 8.4 GHz to observe 59 sources drawn from the Sloan Digital Sky Survey…

In order to test the unification scheme for double-lobed radio sources, the far-infrared properties of matched samples of radio-galaxies and radio-loud quasars were studied using ISOPHOT. The quasar data were complemented with nearly…

Quasars are objects of high interest in extragalactic astrophysics, cosmology, and astrometry. One of their useful qualities is their potential radio loudness. However, the fraction of radio-loud vs. radio-quiet quasars is subject to…

We have found empirically that the radio loudness of AGN can be understood as function of both the X-ray and optical luminosity. This way of considering the radio loudness was inspired by the hardness-intensity diagrams for X-ray binaries,…

We review the statistical properties of the main populations of radio sources, as emerging from radio and millimeter sky surveys. Recent determinations of local luminosity functions are presented and compared with earlier estimates still in…

We match quasars discovered in a multi-color survey centered on the northern Hubble Deep Field (HDF) with radio sources from an ultra-deep radio survey. Although 3 out of 12 quasars are detected at a level below 0.2 mJy at 1.4 GHz, all of…

(Abridged) I present a predictive analysis for the behavior of the FIR--radio correlation as a function of redshift in light of the deep radio continuum surveys which may become possible using the SKA. To keep a fixed ratio between the FIR…

We revisit the nature of the FIR/Radio correlation by means of the most recent models for star forming galaxies. We model the IR emission with our population synthesis code, GRASIL (Silva et al. 1998). As for the radio emission, we revisit…

We present deep radio observations of the most distant complete quasar sample drawn from the Sloan Digital Sky Survey. Combining our new data with those from literature we obtain a sample which is ~100 per cent complete down to S_1.4GHz =…