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Related papers: The host galaxies of BL Lac objects in the near--i…

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(abridged) We present near-infrared Ks-band imaging of 13 high redshift (0.6 < z < 1.3) BL Lac objects. We clearly detect the host in eight objects, and marginally in three others. In all cases, the host galaxy is well represented by an…

Astrophysics · Physics 2009-11-11 J. K. Kotilainen , T. Hyvonen , R. Falomo

We investigate the properties of the host galaxies of X-ray selected (high frequency peaked) BL Lac objects using a large and homogeneous data set of high spatial resolution R-band observations of 52 BL Lacs in the EMSS and Slew samples.…

Astrophysics · Physics 2007-05-23 R. Falomo , J. K. Kotilainen

Snapshot images of about 100 BL Lac objects were obtained with WFPC2 on HST. Sources from various samples, in the redshift range 0.05 to 1.2, were observed and 61 resolved (51 with known z). The high resolution and homogeneity of the images…

Astrophysics · Physics 2016-08-30 R. Falomo , C. Megan Urry , Riccardo Scarpa , Joseph E. Pesce , Aldo Treves

We present B-band imaging of 18 low redshift (z<0.3) BL Lac objects for which their host galaxies were previously resolved in the R-band and the near-infrared H-band. For a subset of the objects, also U- and V-band imaging is presented.…

Astrophysics · Physics 2015-05-13 T. Hyvonen , J. K. Kotilainen , R. Falomo , E. Orndahl , T. Pursimo

We present H-band imaging of 23 low redshift (z < 0.3) BL Lac objects that were previously investigated by us in the R-band. For all the observed objects, the host galaxy is well represented by an elliptical model, with average scale length…

Astrophysics · Physics 2009-11-10 J. K. Kotilainen , R. Falomo

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…

Astrophysics · Physics 2009-10-31 R. Falomo , R. Scarpa , A. Treves , C. M. Urry

Multi-band near-infrared images of twelve BL Lacertae objects were obtained with the 2.5m telescope at the Las Campanas Observatory in order to determine the properties of their underlying host galaxies. Resolved emission was clearly…

Astrophysics · Physics 2009-11-10 C. C. Cheung , C. Megan Urry , Riccardo Scarpa , Mauro Giavalisco

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…

Astrophysics · Physics 2009-11-13 B. Sbarufatti , A. Treves , R. Falomo

We present the results of a high resolution (0.27 arcsec/px) near-infrared H band (1.65 micron) imaging survey of a complete sample of 20 flat spectrum radio quasars (FSRQ) extracted from the 2Jy catalogue of radio sources. The observed…

Astrophysics · Physics 2016-08-30 J. K. Kotilainen , R. Falomo , R. Scarpa

Aims. We aim to determine the redshift (or stringent lower limits) of a number of bright BL Lacs objects. Methods. We secured medium resolution optical and near-infrared spectra of 4 bright BL Lac objects of unknown redshift using the…

Astrophysics of Galaxies · Physics 2014-11-05 Marco Landoni , Renato Falomo , Aldo Treves , Boris Sbarufatti

Six BL Lac objects from the complete 1 Jy radio-selected sample of 34 objects were observed in Cycle 5 with the HST WFPC2 camera to an equivalent limiting flux of mu_I~26 mag/arcsec^2. Here we report results for the second half of this…

We have used the HST WFPC2 camera to survey 132 BL Lac objects comprising seven complete radio-, X-ray-, and optically-selected samples. We obtained useful images for 110 targets spanning the redshift range 0 < z < 1.3. In two thirds of the…

Direct redshift determination of BL Lac objects is highly challenging as the emission in the optical and near-infrared (NIR) bands is largely dominated by the non-thermal emission from the relativistic jet that points very close to our line…

We have obtained high dynamic range, good natural seeing i' images of BL Lacertae objects (BL Lacs) to search for the AGN host and thus constrain the source redshift. These objects are drawn from a sample of bright flat-spectrum radio…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Aaron M. Meisner , Roger W. Romani

Aims: We present optical spectroscopy of a sample of BL Lac objects, to determine their redshift, to study their broad emission line properties and to characterize their close environment. Methods: Twelve objects were observed using the ESO…

Astrophysics · Physics 2009-11-11 B. Sbarufatti , R. Falomo , A. Treves , J. Kotilainen , .

We present high spatial resolution near-infrared H-band (1.65 microns) images, taken with ISAAC on UT1 of ESO VLT, of three radio-loud quasars at z = 1.5, as a pilot study for imaging of a larger sample of radio-loud and radio-quiet quasars…

Astrophysics · Physics 2009-10-31 Renato Falomo , Jari Kotilainen , Aldo Treves

We present near-infrared H-band imaging of 15 intermediate redshift (0.5<z<1) radio quiet quasars (RQQ) in order to characterize the properties of their host galaxies. We are able to clearly detect the surrounding nebulosity in 12 objects,…

Astrophysics · Physics 2015-06-24 T. Hyvonen , J. K. Kotilainen , E. Orndahl , R. Falomo , M. Uslenghi

We have obtained WIYN and SOAR i' images of BL Lacertae objects (BL Lacs) and used these to detect or constrain the flux of the host galaxy. Under common standard candle assumptions these data provide estimates of, or lower bounds on, the…

Astrophysics of Galaxies · Physics 2015-06-18 Matt Stadnik , Roger W. Romani

We report on a large HST imaging survey of BL Lac objects, at spatial resolution ~10 times better than previous ground-based surveys. We focus on data reduction and analysis, describing the procedures used to model the host galaxy surface…

Astrophysics · Physics 2009-10-31 Riccardo Scarpa , C. Megan Urry , Renato Falomo , Joseph E. Pesce , Aldo Treves

We present near-infrared imaging with ESO VLT+ISAAC of the host galaxies of low luminosity quasars in the redshift range 1 < z < 2, aimed at investigating the relationship between the nuclear and host galaxy luminosities at high redshift.…

Astrophysics · Physics 2011-02-11 J. K. Kotilainen , R. Falomo , M. Labita , A. Treves , M. Uslenghi
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