相关论文: FR II Quasars: Infrared Properties, Star Formation…
With the Spitzer Space Telescope Infrared Spectrograph (IRS) we have observed seven powerful FR2 radio galaxies and seven quasars. Both samples, the galaxies and the quasars, are comparable in isotropic 178 MHz luminosity (10^26.5 W/Hz < P…
We present the complete set of ISOPHOT observations of 3CR radio galaxies and quasars, which are contained in the ISO Data Archive, providing 75 mid- and far-infrared spectral energy distributions (SEDs) between 5 and 200 micron. For 28…
The star formation activity of the host galaxies of active galactic nuclei (AGNs) provides valuable insights into the complex interconnections between black hole growth and galaxy evolution. A major obstacle arises from the difficulty of…
We present mid-infrared observations of 18 sources from a sample of 21 z~2 radio-intermediate obscured quasars. The mid-infrared spectra of the sources are continuum dominated, and 12 sources show deep silicate absorption with tau_9.7~1-2.…
We present preliminary results on fitting of SEDs to 142 z>1 quasars selected in the mid-infrared. Our quasar selection finds objects ranging in extinction from highly obscured, type-2 quasars, through more lightly reddened type-1 quasars…
We present the ISO far-IR photometry of a complete sub-sample of optically selected bright quasars belonging to two complete surveys selected through multicolour (U,B,V,R,I) techniques. The ISOPHOT camera on board of the ISO Satellite was…
We present 0.5 -160 micron Spectral Energy Distributions (SEDs) of galaxies, detected at 70microns with the Multiband Imaging Photometer for Spitzer (MIPS), using broadband imaging data from Spitzer and ground-based telescopes.…
We have performed a spectroscopic study of 7 Type 2 QSOs using the mid-infrared spectrometer IRS on board the Spitzer Space Telescope. These are (to our knowledge) the first mid-IR spectra of X-ray selected QSO2s taken. The objects have…
We present Spitzer Space Telescope photometry of 18 Sloan Digital Sky Survey (SDSS) quasars at 2.7 <= z <= 5.9 which have weak or undetectable high-ionization emission lines in their rest-frame ultraviolet (UV) spectra (hereafter weak-lined…
We have explored the nature of the extended emission-line region around the z=0.37 quasar 4C 37.43, using extensive ground-based and HST imaging and spectroscopy. The velocity field of the ionized gas shows gradual gradients within…
We present long-slit near-infrared spectroscopic observations of six nearby (z$\sim$0.1) radio-quiet type-2 quasars (QSO2s) from the Quasar Feedback (QSOFEED) sample. They have bolometric luminosities of $10^{45-46}~erg~s^{-1}$ and stellar…
We present millimeter and radio observations of 13 SDSS quasars at reshifts z~6. We observed eleven of them with the Max-Planck Millimeter Bolometer Array (MAMBO-2) at the IRAM 30m-telescope at 250 GHz and all of them with the Very Large…
Type 2 quasars are luminous Active Galactic Nuclei whose central engines are seen through large amounts of gas and dust. We present Spitzer spectra of twelve type 2 quasars selected on the basis of their optical emission line properties.…
Near-infrared spectra of four QSOs located at $z>6$ are obtained with the OH-airglow suppressor mounted on the Subaru telescope. The FeII/MgII emission-line ratios of these QSOs are examined by the same fitting algorithm as in our previous…
We present the optical-near infrared spectral energy distributions (SED) and near infrared variability properties of 30 low-redshift iron low-ionization Broad Absorption Line quasars (FeLoBALQs) and matched samples of LoBALQs and unabsorbed…
We have assembled a sample of 37 RLQs that have been imaged with the HST in order to investigate their black hole masses, accretion rates, and the structure of their accretion disks. The black hole masses were estimated from the…
We report new continuum observations of fourteen z~6 quasars at 250 GHz and fourteen quasars at 1.4 GHz. We summarize all recent millimeter and radio observations of the sample of the thirty-three quasars known with 5.71<=z<=6.43, and…
We investigate the far-infrared-radio correlation (FRC) of stellar-mass-selected galaxies in the Extended Chandra Deep Field South using far-infrared imaging from Spitzer and radio imaging from the Very Large Array and Giant Metre-Wave…
We examine star formation activity in a distance- (z<0.1) and flux-limited sample of quasars (QSOs). Mid-infrared (MIR) spectral diagnostics at high spatial resolution (~0.4 arcsec) yield star formation rates (SFRs) in the inner regions…
We present results of the analysis of near infrared spectroscopic observations of 6 high-redshift quasars (z > 4), emphasizing the measurement of the ultraviolet FeII/MgII emission line strength in order to estimate the beginning of intense…