Related papers: Quasar Host Environments: The view from Planck
We have observed nine QSOs with redshifts 0.85 to 4.16 at near-IR wavelengths with the adaptive optics bonnette of the Canada-France-Hawaii telescope. Exposure times ranged from 1500 to 24000s (mostly near 7000s) in J, H, or K bands, with…
We analyse the proximity zone of the intergalactic matter around high-redshift quasars in a cosmological environment. In a box of 64 h-1 Mpc base length we employ dark matter only simulations. For estimating the hydrogen temperature and…
We investigate the ability of hierarchical models of QSO formation and evolution to match the observed luminosity, number counts and spatial clustering of quasars at redshift z<2. These models assume that the QSO emission is triggered by…
In order to test the unified scheme for luminous radio galaxies and quasars we observed 10 galaxy/quasar pairs from the 3CR catalogue with ISOPHOT at infrared wavelengths between 5 and 180 micron. Each pair was selected such that both the…
We measure the spectral properties of a representative sub-sample of 187 quasars, drawn from the Parkes Half-Jansky, Flat-radio-spectrum Sample (PHFS). Quasars with a wide range of rest-frame optical/UV continuum slopes are included in the…
Cross-correlating the Planck High Frequency Instrument (HFI) maps against quasars from the Sloan Digital Sky Survey (SDSS) DR7, we estimate the intensity distribution of the Cosmic Infrared Background (CIB) over the redshift range 0 < z <…
We report Herschel SPIRE (250, 350, and 500 micron) detections of 32 quasars with redshifts 0.5 < z < 3.6 from the Herschel Multi-tiered Extragalactic Survey. These sources are from a MIPS 24 micron flux-limited sample of 326 quasars in the…
We have conducted a NIR study of the environments of seven radio-loud quasars at redshifts 1<z<1.6. In present paper we describe deep $K$ band images obtained for the fields of ~6X6 arcmin around the quasars with 3$\sigma$ limiting…
We present the results of an infrared survey of QSO fields at z=0.95, 0.995 and 1.5. Each z<1 field was imaged to typical continuum limits of J=20.5, Kprime=19 (5 sigma), and line fluxes of 1.3E10{-16}ergs/cm^2/s (1 sigma)in a 1%…
The interstellar medium is crucial to understanding the physics of active galaxies and the coevolution between supermassive black holes and their host galaxies. However, direct gas measurements are limited by sensitivity and other…
Observations of quasars (QSOs) shining through or close to galaxies offer a way to probe the properties of the foreground matter through dust extinction and gravitational lensing. In this paper the feasibility of measuring the dust…
We present ALMA band 3 observations of the CO(6-5), CO(7-6), and [CI] 369micron emission lines in three of the highest redshift quasar host galaxies at 6.6<z<6.9. These measurements constitute the highest-redshift CO detections to date. The…
We study the differences in physical properties of quasar-host galaxies using an optically selected sample of radio loud (RL) and radio quiet (RQ) quasars (in the redshift range 0.15 < z < 1.9) which we have further cross-matched with the…
The evolution of QSO clustering is investigated with a new sample of 388 QSOs with 0.3<z<2.2, B<20.5 and M_B<-23. Evidence is found for an increase of the clustering amplitude with increasing redshift. These measurements allow to further…
We have measured the mid-infrared radiation from an orientation-unbiased sample of powerful 3C RR galaxies and quasars using the IRS and MIPS instruments aboard the Spitzer Space Telescope. We fit the Spitzer data as well as other…
We combine submm photometric data of z>4 quasars, to obtain a mean far-infrared (FIR) (rest-frame) spectral energy distribution (SED) of thermal emission from dust, parameterised by a single temperature (T) and power-law emissivity index…
Fundamental differences in the radio properties of red quasars (QSOs), as compared to blue QSOs, have been recently discovered, positioning them as a potential key population in the evolution of galaxies and black holes across cosmic time.…
Three high-redshift (z=2) and high luminosity (M_B < -28 mag for Ho = 50, qo=0.5) QSOs, two radio-quiet one radio-loud, were imaged in R, I and K bands. The luminosities, colours and sizes of the hosts overlap with those of actively…
In current and future surveys, quasars play a key role. The new data will extend our knowledge of the Universe as it will be used to better constrain the cosmological model at redshift $z>1$ via baryon acoustic oscillation and redshift…
We have observed 104 gravitationally-lensed quasars at $z\sim1-4$ with Herschel/SPIRE, the largest such sample ever studied. By targeting gravitational lenses, we probe intrinsic far-infrared (FIR) luminosities and star formation rates…