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We analyze 23 spectroscopically confirmed Type-2 quasars (QSOs) selected from the WISE 22$\rm \mu$m band in the SDSS Stripe 82 region, focusing on their multi-band photometry and spectral energy distributions (SEDs). These objects were…

The Great Observatories All-Sky LIRG Survey (GOALS) is a multiwavelength study of luminous infrared galaxies (LIRGs) in the local universe. Here we present low resolution Spitzer spectra covering 5-38um and provide a basic analysis of the…

This is the second paper in a series discussing the properties of ultraluminous infrared galaxies (ULIGs: L_ir > 10^{12} L_sun; Ho = 75 km s^{-1} Mpc^{-1} and qo = 0.0) from the 1-Jy sample of Kim (1995). This paper presents the first…

Astrophysics · Physics 2009-10-30 D. -C. Kim , S. Veilleux , D. B. Sanders

We present the AGN, star-forming, and morphological properties of a sample of 13 MIR-luminous (f(24) > 700uJy) IR-bright/optically-faint galaxies (IRBGs, f(24)/f(R) > 1000). While these z~2 sources were drawn from deep Chandra fields with…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 J. L. Donley , G. H. Rieke , D. M. Alexander , E. Egami , P. G. Perez-Gonzalez

We present optical through radio observations of the host galaxies of two dust obscured, luminous quasars selected in the mid-infrared, at z=2.62 and z=2.99, including a search for CO emission. Our limits on the CO luminosities are…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Mark Lacy , Andreea O. Petric , Alejo Martinez-Sansigre , Susan E. Ridgway , Anna Sajina , Tanya Urrutia , Duncan Farrah

We identify and characterize a population of luminous dust poor quasars at 0<z<5, similar in photometric properties to the objects found at z>6 previously. This class of active galactic nuclei has been known to show little IR emission from…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Hyunsung David Jun , Myungshin Im

We present Spitzer/IRS observations of a small sample of heavily obscured IRAS sources displaying both the infrared and OH maser emission characteristic of OH/IR stars on the asymptotic giant branch (AGB), but also radio continuum emission…

Astrophysics · Physics 2012-08-10 D. A. Garcia-Hernandez , J. V. Perea-Calderon , M. Bobrowsky , P. Garcia-Lario

We explore the relationships between the Polycyclic Aromatic Hydrocarbon (PAH) feature strengths, mid-infrared continuum luminosities, far-infrared spectral slopes, optical spectroscopic classifications, and silicate optical depths within a…

The physics and demographics of type 2 quasars remain poorly understood, and new samples of such objects selected in a variety of ways can give insight into their physical properties, evolution, and relationship to their host galaxies. We…

Astrophysics of Galaxies · Physics 2017-03-17 Sihan Yuan , Michael A. Strauss , Nadia L. Zakamska

We present the results of a survey of galaxies selected by their gas cross-section which give rise to MgII absorption lines in the spectra of background quasars. The sample comprises 11 galaxies covering the redshift range 0.7 < z < 1.2,…

Astrophysics · Physics 2007-05-23 Patrick Guillemin , Jacqueline Bergeron

We analyze Hubble Space Telescope observations of scattering regions in 20 luminous obscured quasars at $0.24<z<0.65$ (11 new observations and 9 archival ones) observed at rest-frame $\sim 3000$\AA. We find spectacular $5-10$ kpc-scale…

Astrophysics of Galaxies · Physics 2016-01-27 Georges Obied , Nadia L. Zakamska , Dominika Wylezalek , Guilin Liu

We report on new Chandra exploratory observations of six candidate Type 2 quasars at z=0.49-0.73 selected among the most [OIII] luminous emitters from the Sloan Digital Sky Survey (SDSS). Under the assumption that [OIII] is a proxy for the…

Astrophysics · Physics 2009-11-11 C. Vignali , D. M. Alexander , A. Comastri

Ground-based 2.8--4.1 $\mu$m slit spectra of the nuclei of seven ultraluminous infrared galaxies (ULIRGs) that are classified optically as LINERs and have cool far-infrared colors are presented. All the nuclei show 3.3 $\mu$m polycyclic…

Astrophysics · Physics 2009-11-07 Masatoshi Imanishi , Philip R. Maloney

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…

Astrophysics · Physics 2007-05-23 Alejo Martinez-Sansigre , Steve Rawlings

We have compared the optical emission line ratios of type 2 quasars from Zakamska et al. with standard AGN photoionization model predictions, Seyfert 2s, HII galaxies, and narrow line FRII radio galaxies. Moderate to high ionization narrow…

We present the first detections of the 3um water ice and 3.4um amorphous hydrocarbon (HAC) absorption features in z~2 ULIRGs. These are based on deep rest-frame 2-8um Spitzer IRS spectra of 11 sources selected for their appreciable silicate…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 A. Sajina , H. Spoon , L. Yan , M. Imanishi , D. Fadda , M. Elitzur

We report the results from a comprehensive study of 74 ultraluminous infrared galaxies (ULIRGs) and 34 Palomar-Green (PG) quasars within z ~ 0.3$ observed with the Spitzer Infrared Spectrograph (IRS). The contribution of nuclear activity to…

We present results of a study of 12 dust-reddened quasars with 0.4 < z < 2.65 and reddenings in the range 0.15 < E(B-V) < 1.7. We obtained ACIS-S X-ray spectra of these quasars, estimated the column densities towards them, and hence…

Astrophysics · Physics 2009-11-10 Tanya Urrutia , Mark Lacy , Michael D. Gregg , Robert H. Becker

We have observed seven powerful FR2 radiogalaxies and seven quasars with the Spitzer IRS. Both samples are comparable in both, redshift range and isotropic 178 Hz luminosity. Both samples are found to have similar distributions in the…

Astrophysics · Physics 2007-05-23 Bernhard Schulz , Ralf Siebenmorgen , Martin Haas , Endrik Kruegel , Rolf Chini

We present optical spectra for a representative sample of 27 nearby (z < 0.2) 2MASS-selected AGN with red near-IR colours (J-K 2.0). The spectra were taken with the ISIS spectrograph on the WHT with the aim of determining the nature of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Marvin Rose , Clive Tadhunter , Joanna Holt , Javier Rodríguez Zaurín
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