Related papers: HST snapshot imaging of BL Lac objects

Since no spectroscopic redshift is available for the remarkable BL Lac object 1ES 0647+250, we aim to derive an estimate of its distance from the properties of its host galaxy.We obtained a deep, high-resolution near-infrared H-band image…

We report results from HST/NICMOS 2 micron imaging polarimetry of the central region of Centaurus A. In the vicinity of the nucleus we observe a complex polarization structure which we explain by a combination of scattering of nuclear light…

We report on measurements of the stellar velocity dispersion (sigma) from the optical spectra of the host galaxies of four BL Lac objects. Together with our earlier results on seven BL Lac objects (Falomo et al. 2002), and with the…

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…

We investigate the structural properties of nuclear star clusters in late-type spiral galaxies. More specifically, we fit analytical models to HST images of 39 nuclear clusters in order to determine their effective radii after correction…

We present some results from our HST archival image study of 71 QSO host galaxies. The objects are selected to have z < 0.46 and total absolute magnitude M_V < -23 (H_0=50 km/s/Mpc). This initial study investigates host morphology and radio…

BL Lac objects are low--power active nuclei exhibiting a variety of peculiar properties that are caused by the presence of a relativistic jet and orientation effects. We present here adaptive optics near-IR images at high spatial resolution…

We present the radio detection of 18 BL Lac objects from our survey of over 575 square degrees of sky. These 18 objects are located within 20 arcsec of the X-ray position, of which 11 have a measured red-shift. All candidates are radio…

We report on spectroscopic observations covering most of the 475 BL Lacs in the 2nd Fermi LAT catalog of AGN. Including archival measurements (correcting several erroneous literature values) we now have spectroscopic redshifts for 44% of…

The 143 galaxies with secure redshifts (median z = 0.62) from the 1415+52 field of the Canada-France Redshift Survey have been imaged at CFHT with median seeing of 0.67 arcseconds. Structural parameters have been derived by fitting…

We present 3-band HST imaging of three z</=0.1 compact symmetric objects (CSOs): 4C 31.04, 1946+708 and 1146+596. These objects were chosen on the basis of proximity to Earth as well as HI 21 cm absorption. The inner H-band isophotes of…

We present a sample of 723 optically selected BL Lac candidates from the SDSS DR7 spectroscopic database encompassing 8250 deg^2 of sky; our sample constitutes one of the largest uniform BL Lac samples yet derived. Each BL Lac candidate has…

Context: BL Lac objects are a rare class of active galactic nuclei that typically show featureless optical spectra that make it difficult to estimate the redshift. A novel method for estimating the redshift of BL Lac objects has recently…

We have examined the spectroscopic properties of a sample of 19 optically bright, low luminosity Flat Radio Spectrum (LL FRS) sources. Our study focuses on the properties of their host galaxies, namely the nuclear stellar populations and…

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 report redshift measurements for 12 BL Lacertae objects from a program aimed at obtaining high signal to noise (up to ~ 500) optical spectroscopy of a mixed sample of objects. The new observations, gathered with the 8 m ESO Very Large…

We have measured the central stellar velocity dispersion in the host galaxies of 11 BL Lac objects with redshifts z <= 0.125. The range of velocity dispersions, 170-370 km/s, is similar to that of nearby radio galaxies. Using the…

AIMS. We are studying an unbiased sample of 42 nearby (z < 0.2) BL Lacertae objects with a multi-wavelength approach. The results of VLBI observations were presented in the first paper of this series. In this paper, we study the…

We present a sample of 386 BL Lacertae (BL Lac) candidates identified from 2860 deg^2 of the Sloan Digital Sky Survey (SDSS) spectroscopic database. The candidates are primarily selected to have quasi-featureless optical spectra and low…

We use the extensive public archive of ROSAT High Resolution Imager (HRI) observations to carry out a statistical investigation of the X-ray properties of nearby galaxies. Specifically we focus on the sample of 486 bright (B_T < 12.5)…