相关论文: Mid-infrared spectroscopy of high-redshift obscure…
We report the initial results from a Spitzer GO-1 program to obtain low resolution, mid-infrared spectra of infrared luminous galaxies at z~1-2. This paper presents the spectra of eight sources observed with the Spitzer InfraRed…
Recent works have suggested that selection criteria based on MIR colors can be used to reveal a population of dust-enshrouded, extremely luminous quasars at z>1. However the X-ray spectral properties of these intriguing sources still remain…
The radio properties of 11 obscured `radio-intermediate' quasars at redshifts z>~2 have been investigated using the European Very-Long-Baseline-Interferometry Network (EVN) at 1.66 GHz. A sensitivity of ~25 micro Jy per 14x17 mas2 beam was…
We present mid-infrared spectra of sixteen optically faint sources with 70 micron fluxes in the range 19-38mJy. The sample spans a redshift range of 0.35<z<1.9, with most lying between 0.8<z<1.6, and has infrared luminosities of 10^{12} -…
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.…
We present the mid-infrared (MIR) spectra obtained with the Spitzer InfraRed Spectrograph (IRS) for a sample of 52 sources, selected as infrared luminous, z>1 candidates in the Extragalactic First Look Survey (XFLS). The sample selection…
We have measured mid-infrared radiation from an orientation-unbiased sample of 3CRR galaxies and quasars at redshifts 0.4 < z < 1.2 with the IRS and MIPS instruments on the Spitzer Space Telescope. Powerful emission (L_24micron > 10^22.4…
Low spectral resolution (delta lambda/lambda ~ 50) mid-infrared observations with high angular resolution (0.3--0.5'') using the Long Wavelength Spectrometer on the Keck I Telescope are reported of the nuclei of five highly luminous…
Using mid-infrared and radio criteria, we select a sample of candidate z~2 obscured quasars. Optical spectroscopy confirms about half of these as type-2 quasars, and modelling the population suggests 50-80% of the quasars are obscured. We…
We present a multiwavelength spectroscopic survey of 23 luminous mid-infrared-selected Type-2 quasars at redshifts z = 0.88 to 3.49. The targets were selected in the SDSS Stripe 82 field based on their bright WISE W4 detections (flux > 5…
Mid-infrared (MIR) quasar spectra exhibit a suite of emission features including high ionization coronal lines from the narrow line region illuminated by the ionizing continuum, broad dust bumps from silicates and graphites, and polycyclic…
We discuss the relative merits of mid-infrared and X-ray selection of type-2 quasars. We describe the mid-infrared, near-infrared and radio selection criteria used to find a population of redshift z~2 type-2 quasars which we previously…
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…
We want to study the mid-infrared properties and the starburst and AGN contributions, of 24um sources at z~2, through analysis of mid-infrared spectra combined with millimeter, radio, and infrared photometry. Mid-infrared spectroscopy…
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 observations at 1.2 mm with MAMBO-II of a sample of z>~2 radio-intermediate obscured quasars, as well as CO observations of two sources with the Plateau de Bure Interferometer. Five out of 21 sources (24%) are detected at a…
We present the infrared (IR) and X-ray properties of a sample of 33 mid-IR luminous quasars ($\nu$L(6 micron)>6x10$^{44}$ erg/s) at redshift z~1-3, identified through detailed spectral energy distribution analyses of distant star-forming…
We present new mid-infrared and submillimetre observations for a sample of eight high redshift type-2 QSOs located in the Chandra Deep Field South. The sources are X-ray absorbed with luminosities in excess of 10^44 erg/s. Two of the…
We present mid-IR spectral decomposition of a sample of 48 Spitzer-selected ULIRGs spanning z~1-3 and likely L_IR~10^12-10^13Lsun. Our study aims at quantifying the star-formation and AGN processes in these sources which recent results…
The spectral energy distributions and infrared (IR) spectra of a sample of obscured AGNs selected in the mid-IR are modeled with recent clumpy torus models to investigate the nature of the sources, the properties of the obscuring matter,…