Related papers: Unifying models for X-ray selected and Radio selec…
We report results from {\it XMM-Newton} observations of thirteen X-ray bright BL Lacertae objects, selected from the {\it Einstein} Slew Survey sample. The spectra are generally well fit by power-law models, with four objects having hard…
We review the statistical properties of the main populations of radio sources, as emerging from radio and millimeter sky surveys. Recent determinations of local luminosity functions are presented and compared with earlier estimates still in…
The broadband spectral energy distribution(SED) of blazars is generally interpreted as radiation arising from synchrotron and inverse Compton mechanisms.Traditionally, the underlying source parameters responsible for these emission…
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…
Context: We present the results of a set of observations of nine TeV detected BL Lac objects performed by the XRT and UVOT detectors on board the Swift satellite between March and December 2005. Aims: We are mainly interested in measuring…
We review the main results from several radio, X-ray and multi-frequency surveys on the topic of cosmological evolution of BL Lacertae objects. Updated findings on BL Lac evolution following the recent identification of many sources in the…
We have recently proposed a new scenario where blazars are classified as flat-spectrum radio quasars or BL Lacs according to the prescriptions of unified schemes, and to a varying combination of Doppler boosted radiation from the jet,…
We analyse 77 \textit{Fermi} sources and their potential low-energy counterparts previously proposed in the literature. These sources were classified as active galactic nuclei, mainly blazars, based on optical spectroscopy. The main goals…
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.…
We present and discuss polarimetric observations of 182 targets drawn from an optically selected sample of 240 probable BL Lac candidates out of the SDSS compiled by Collinge et al. (2005). In contrast to most other BL Lac candidate samples…
Light curves of eight BL Lac objects in the BVRI bands have been analyzed. All of the objects tend to be bluer when brighter. However spectral slope changes differ quantitatively from those of a sample of QSOs analyzed in a previous paper…
We present the analysis of archival data from ROSAT and ASCA of a serendipitous BL Lac object PKS 2316-423. Because of its featureless non-thermal radio/optical continuum, PKS 2316-423 has been called as a BL Lac candidate in the…
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…
Radio relics are the manifestation of electrons presumably being shock (re-)accelerated to high energies in the outskirts of galaxy clusters. However, estimates of the shocks' strength yield different results when measured with radio or…
Low-frequency radio surveys allow in-depth studies and new analyses of classes of sources previously known and characterised only in other bands. In recent years, low radio frequency observations of blazars have been available thanks to new…
The multi-frequency Sedentary Survey is a flux limited, statistically well-defined sample of highly X-ray dominated BL Lacertae objects (HBLs) which includes 150 sources. In this paper, the third of the series, we report the results of a…
We present the results of an extensive analysis of the optical, ultraviolet, X-ray and $\gamma$-ray data collected from the observations of the BL Lac objects prototype BL Lacertae carried out over a period of nearly 13 years, between…
We present the results of nine years of the blazar observing programme at the RATAN-600 radio telescope (2005-2014). The data were obtained at six frequency bands (1.1, 2.3, 4.8, 7.7, 11.2, 21.7 GHz) for 290 blazars, mostly BL Lacs. In…
We revisit the blazar sequence exploiting the complete, flux limited sample of blazars with known redshift detected by the Fermi satellite after 4 years of operations (the 3LAC sample). We divide the sources into gamma-ray luminosity bins,…
S5 0716+714 is a typical BL Lacertae object. In this paper we present the analysis and results of long term simultaneous observations in the radio, near-infrared, optical, X-ray and $\gamma$-ray bands, together with our own photometric…