Related papers: High-redshift quasar host galaxies with adaptive o…
We report on deep near-infrared F125W (J) and F160W (H) Hubble Space Telescope Wide Field Camera 3 images of the z=6.42 quasar J1148+5251 to attempt to detect rest-frame near-ultraviolet emission from the host galaxy. These observations…
The Mbh-Mhost relation in quasars has been probed only in a limited parameter space, namely at Mbh~10^9 Msun and Mhost~10^12 Msun. Here we present a study of 26 quasars lying in the low-mass end of the relation, down to Mbh~10^7 Msun. We…
We present an analysis of the galaxy distribution surrounding 15 of the most luminous (>10^{14} L_sun; M_1450 ~ -30) QSOs in the sky with z~2.7. Our data are drawn from the Keck Baryonic Structure Survey (KBSS). In this work, we use the…
We present deep Gemini GMOS optical spectroscopy of nine luminous quasars at redshifts z ~ 0.5, drawn from the SDSS type 2 quasar sample. Our targets were selected to have high intrinsic luminosities (M_V < -26 mag) as indicated by the [O…
The HST snapshot imaging survey of 110 BL Lac objects (Urry et al. 2000) has clearly shown that the host galaxies are massive and luminous ellipticals. The dispersion of the absolute magnitudes is sufficiently small, so that the measurement…
We present the first result of a comprehensive spectroscopic study of quasar host galaxies. On-axis, spatially resolved spectra of low redshift quasars have been obtained with FORS1, mounted on the 8.2m ESO Very Large Telescope, Antu. The…
We report on our XMM observations of the high redshift quasars BR 2237--0607 (z=4.558) and BR 0351--1034 (z=4.351), together with 14 other z>4 objects found in the XMM public archive. Contrary to former reports, we do not find high redshift…
We present a weak lensing and photometric study of six half by half degree fields observed at the CFHT using the UH8K CCD mosaic camera. The fields were observed for a total of 2 hours each in I and V, resulting in catalogs containing ~ 20…
We present near-infrared spectra of ten luminous, intermediate redshift quasars observed with SofI at the NTT of ESO/La Silla. With these rest-frame optical spectra we probe the Hb -[OIII] emission line region. Using the standard scaling…
Recently, the relation between the masses of the black hole ($M_{BH}$) and the host galaxy ($M_{host}$) in quasars has been probed down to the parameter space of $M_{BH}\sim10^8 M_\odot$ and $M_{host}\sim10^{11} M_\odot$ at z $<$ 0.5. In…
We obtained optical spectroscopy of close (< 80 kpc) companion objects of a sample of 12 low redshift quasars (z < 0.3 ) selected from the SDSS Stripe82 area and that are in the subsample of 52 QSOs for which both multicolor host galaxies…
We present a new measurement of the space density of high redshift (3.0<z<4.5), X-ray selected QSOs obtained by exploiting the deep and uniform multiwavelength coverage of the COSMOS survey. We have assembled a statistically large (40…
We investigate the relationship between the mass of the central supermassive black hole, M_bh, and the host galaxy luminosity, L_gal, in a sample of quasars from the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7). We use composite…
The observed number counts of quasars may be explained either by long-lived activity within rare massive hosts, or by short-lived activity within smaller, more common hosts. It has been argued that quasar lifetimes may therefore be inferred…
Black-hole masses of the highest redshift quasars (4 <~ z <~ 6) are estimated using a previously presented scaling relationship, derived from reverberation mapping of nearby quasars, and compared to quasars at lower redshift. It is shown…
Starting from the ~50000 quasars of the Sloan Digital Sky Survey for which MgII line width and 3000 A monochromatic flux are available, we aim to study the dependence of the mass of active black holes on redshift. We focus on the observed…
We analyse the environment of low redshift, z < 0.2, SDSS quasars using the spectral and photometric information of galaxies from the Sloan Digital Sky Survey Third Data Release (SDSS-DR3). We compare quasar neighbourhoods with field and…
We present a study of the morphology and intensity of star formation in the host galaxies of eight Palomar-Green quasars using observations with the Hubble Space Telescope. Our observations are motivated by recent evidence for a close…
Proximity zones of high-redshift quasars are unique probes of supermassive black hole formation, but simultaneously explaining proximity zone sizes and black hole masses has proved to be challenging. We study the robustness of some of the…
The advent of the James Webb Space Telescope has revolutionised our understanding of the high-redshift Universe through its detection of bright, massive galaxies up to $z\gtrsim 10$ and its identification of peculiar sources called `little…