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Related papers: HST snapshot imaging of BL Lac objects

200 papers

A Hubble Space Telescope snapshot survey of the B2 sample of low luminosity radio galaxies has, at present, produced V and I images of 41 objects. Together with 16 images of B2 sources taken from the HST archive, there are now high…

Astrophysics · Physics 2007-05-23 A. Capetti , H. R. de Ruiter , R. Fanti , R. Morganti , P. Parma , M. -H. Ulrich

We investigate the host galaxy luminosities of BL Lac Objects (BLLs) and Radio Loud Quasars (RLQs) at z<0.5 imaged with the Hubble Space Telescope (HST). From a homogeneous treatment of the data we construct the host galaxy luminosity…

Astrophysics · Physics 2009-11-07 Renato Falomo , Nicoletta Carangelo , Aldo Treves

We present optical images and spectroscopy for a dozen of BL Lac objects. Most of these objects were not previously studied and we give for the first time the properties of their host galaxies. The properties of the new host galaxies are…

Astrophysics · Physics 2009-09-25 Renato Falomo , Marie-Helene Ulrich

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

We examine the optical properties of the nuclei of low luminosity radio-galaxies using snapshot HST images of the B2 sample. In agreement with the results obtained from the analysis of the brighter 3C/FRI sample, we find a correlation…

Astrophysics · Physics 2009-11-07 A. Capetti , A. Celotti , M. Chiaberge , H. R. de Ruiter , R. Fanti , R. Morganti , P. Parma

Host galaxies of Active Galactic Nuclei give crucial information on the interaction between accreting Supermassive Black Holes and their surroundings, and on their common evolution. Their study in the case of aligned jetted AGN - BL…

High Energy Astrophysical Phenomena · Physics 2026-03-18 Gaia Delucchi , Tullia Sbarrato , Giorgio Calderone , Chiara Righi , Silvano Tosi , Boris Sbarufatti

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

We present morphological and photometric properties of 79 low redshift (z<0.12) radio galaxies extracted from two radio flux limited samples of radio sources. All objects are imaged in the R band and for a subsample we have also obtained B…

Astrophysics · Physics 2007-05-23 F. Govoni , R. Falomo , G. Fasano , R. Scarpa

High-resolution images of 7 newly identified BL Lac objects (among them one BL Lac candidate) at z < 0.2 from the Einstein Slew Survey are presented for the first time. In all cases we were able to resolve the host galaxy. Our 2-dimensional…

Astrophysics · Physics 2007-05-23 J. Heidt , K. Nilsson , A. Sillanpaeae , L. O. Takalo , T. Pursimo

Hubble Space Telescope (HST) observations provide a novel way of testing unified models for FR I radio sources and BL Lac objects. The detection of extended dust discs in some radio galaxies provides information on their jet orientation.…

Astrophysics · Physics 2009-10-31 Alessandro Capetti , Annalisa Celotti

We present new radio data completing the imaging for a sample of 30 nearby (z < 0.2) BL Lac objects on parsec and kiloparsec scale. The sample is composed of both high and low luminosity sources and it is therefore an ideal test bed for…

Astrophysics · Physics 2007-05-23 M. Giroletti , G. Giovannini , G. B. Taylor , R. Falomo

We will present the results of a NICMOS H-band imaging survey of a small sample of z ~ 2 to 3 radio-quiet quasars. We have resolved extension in at least 4 of 5 objects and find evidence for a wide range in the morphologies and magnitudes…

Astrophysics · Physics 2009-10-31 S. Ridgway , T. Heckman , D. Calzetti , M. Lehnert

\textbf{Context.} Deep optical surveys open the avenue for find large numbers of BL Lac objects that are hard to identify because they lack the unique properties classifying them as such. While radio or X-ray surveys typically reveal dozens…

Astrophysics of Galaxies · Physics 2014-09-30 S. D. Kügler , K. Nilsson , J. Heidt , J. Esser , T. Schultz

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

We present HST observations of seven unusual objects from the HST ``snapshot survey'' of BL Lac objects, of which four are gravitational lens candidates. In three cases a double point sources is observed: 0033+595, with 1.58 arcsec…

Astrophysics · Physics 2009-10-31 R. Scarpa , C. M. Urry , R. Falomo , J. E. Pesce , R. Webster , M. O'Dowd , A. Treves

BL Lac objects (BLL) are defined by the presence of very weak (typically $<$ 5 {\AA}) or even absent spectral lines. This makes determining their distance particularly challenging, especially at high redshift, where the sources are fainter…

Astrophysics of Galaxies · Physics 2026-04-01 Renato Falomo , Aldo Treves , Simona Paiano , Riccardo Scarpa

We explore the viability of the unification of BL Lacs and FR I radio galaxies by comparing the core emission of radio galaxies with those of BL Lacs, taking advantage of the newly measured optical nuclear luminosity of FR I sources. The…

Astrophysics · Physics 2007-05-23 Marco Chiaberge , Annalisa Celotti , Alessandro Capetti , Gabriele Ghisellini

We searched the HST archives for unpublished WFPC2 images of low redshift (z<0.5) radio loud quasars (RLQ). This led to the identification of 11 objects. We present here the results of the analysis of these images from which we derive the…

Astrophysics · Physics 2009-11-10 C. Pagani , R. Falomo , A. Treves

We present a new sample of 30 nearby (z<0.2) BL Lacs, selected to study the nuclear as well as the large scale properties of low power radio sources. In this first paper, we show and discuss new radio data taken with the VLA (19 objects at…

Astrophysics · Physics 2009-11-10 M. Giroletti , G. Giovannini , G. B. Taylor , R. Falomo

We report on new measurements of the stellar velocity dispersion of 4 BL Lac objects for which optical spectroscopy was gathered at the ESO 3.6m using EFOSC2. Assuming the M(BH)--(sigma) relation is valid also for ellipticals hosting active…

Astrophysics · Physics 2007-05-23 A. Treves , N. Carangelo , R. Falomo , J. Kotilainen