Related papers: IMAGING OF LOW REDSHIFT QSOs WITH WFPC2
A clear insight of the galaxies hosting active galactic nuclei is of fundamental importance for understanding the processes of galaxies and nuclei formation and their cosmic evolution. A good characterization of the host galaxies properties…
Photometry is presented in R, J, H, K of the z=2.37 QSO 0820+296 and its environment. Colours and magnitudes of most of the objects within 50 arcsec of the QSO suggest they are a group of galaxies at the QSO redshift with a young stellar…
Type II quasars are luminous Active Galactic Nuclei whose centers are obscured by large amounts of gas and dust. In this paper we present 3-band HST images of nine type II quasars with redshifts 0.2 < z < 0.4 selected from the Sloan Digital…
We describe the first results from a comprehensive study of the distant cluster Cl0024+1654 (z=0.39) based upon a pattern of 38 mosaiced HST-WFPC2 images extending to radii ~5Mpc. These are being analysed in conjunction with extensive…
We report the serendipitous discoveries of companion galaxies to two high-redshift quasars. SDSS J025617.7+001904 is a z=4.79 quasar included in our recent survey of faint quasars in the SDSS Stripe 82 region. The initial MMT slit…
To expand the known number of low-redshift galaxies which lie close to bright ($V < 17.2$) QSO lines of sight, we have identified 24 galaxies within 11 arcmins of nine QSOs which have been observed with the Hubble Space Telescope (HST).…
We present spectroscopic observations of galaxies lying within 1' from the QSO J2233-606 in the HDF-S. Several are found to be coincident in redshift with absorption line systems seen in the HST spectrum of the QSO. We detect a new quasar…
We present deep Hubble Space Telescope Wide Field Camera 3 slitless spectroscopic observations of the distant cluster Cl J1449+0856. These cover a single pointing with 18 orbits of G141 spectroscopy and F140W imaging, allowing us to derive…
In this paper we present new ESO/VLT FORS1 and ISAAC images of the fields around eight gravitationally lensed quasars: CTQ414, HE0230-2130, LBQS1009-0252, B1030+074, HE1104-1805, B1359+154, H1413+117 and HE2149-2745. When available and deep…
We report the discovery of two radio-loud quasars with redshifts greater than four; GB1428+4217 with z=4.72 and GB1713+2148 with z=4.01. This doubles the number of published radio-selected quasars with z > 4, bringing the total to 4.…
We report on the optical properties of a sample of 30 BL Lac host galaxies in the redshift range $0.03<z<0.2$, as derived from HST observations. All galaxies are fully resolved in the WFPC2 (F702W filter) images, allowing a quantitative…
Observations of multiple or lensed QSOs at high redshift can be used to probe transverse structure in intervening absorption systems. Here we present results obtained from STIS spectroscopy of the unique triply imaged QSO APM08279+5255 at z…
HST images (WFC2) of \pks show that this luminous nearby quasar is interacting with diffuse (presumably galactic) material. Two thin wisps that have a total extent of about 20 kpc (for $H_0 = 100$ \kms ${\rm Mpc}^{-1}$ and $\Omega_0 = 1.0$)…
We present near-IR images, obtained with the Hubble Space Telescope (HST) and the WFC3/IR camera, of six passive and massive galaxies at redshift 1.3<z<2.4 (SSFR<10^{-2} Gyr^{-1}; stellar mass M~10^{11} M_{sun}), selected from the Great…
HST observations of eight intrinsically luminous quasars with redshifts between $0.16$ and~$0.29$ are presented. Seven companion galaxies brighter than $M_V = -16.5$ lie within a projected distance of 25 kpc of the quasars; three of the…
We test the hypothesis whether high redshift QSOs would preferentially appear in small groups or pairs, and if they are associated with massive, young clusters. We carried out a photometric search for \Ly emitters on scales $\lesssim 10…
We present results on two related topics: 1. A discussion of high redshift candidates (z>4.5), and 2. A study of very small galaxies at intermediate redshifts, both sets being detected in the region of the northern Hubble Deep Field covered…
The strong radio source 3C343.1 consists of a galaxy and a QSO separated by no more than about 0.25 arcsec. The chance of this being an accidental superposition is conservatively 10^-8. The z=0.344 galaxy is connected to the z=0.750 QSO by…
A significant minority of high redshift radio galaxy (HzRG) candidates show extremely red broad band colours and remain undetected in emission lines after optical `discovery' spectroscopy. In this paper we present deep GTC optical imaging…
We present the first results from a new survey for high-redshift $(z\gtrsim5)$ gravitationally lensed quasars and close quasar pairs. We carry out candidate selection based on the colors and shapes of objects in public imaging surveys, then…