English
Related papers

Related papers: The CLASS BL Lac sample: The Radio Luminosity Func…

200 papers

In a previous paper, we proposed a new method to select low-power BL Lacs (LPBLs) based on mid-infrared emission and flux contrast through the Ca II spectral break; that study led to the selection of a complete sample formed by 34 LPBLs…

Astrophysics of Galaxies · Physics 2016-02-17 Claudia M. Raiteri , Alessandro Capetti

We measure the radio luminosity function (RLF) of steep-spectrum radio sources using three redshift surveys of flux-limited samples selected at low (151 & 178 MHz) radio frequency, low-frequency source counts and the local RLF. The redshift…

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 J. Heidt , K. Nilsson

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 M. W. B. Anderson , M. D. Filipović

Historically, the blazar population has been poorly understood at low frequencies because survey sensitivity and angular resolution limitations have made it difficult to identify megahertz counterparts. We used the LOFAR Two-Metre Sky…

We present a hierarchical Bayesian framework designed to infer the luminosity function of any class of object by jointly modelling data from multiple surveys with varying depth, completeness, and sky coverage. Our method explicitly accounts…

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…

High Energy Astrophysical Phenomena · Physics 2018-11-08 F. D'Ammando , M. Giroletti , S. Rainò

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…

Astrophysics of Galaxies · Physics 2017-07-26 M. Mingaliev , Yu. Sotnikova , T. Mufakharov , E. Nieppola , M. Tornikoski , J. Tammi , A. Lahteenmaki , R. Udovitskiy , A. Erkenov

\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

Observations at millimetre wavelengths are presented for a representative sample of 22 X-ray-selected BL Lac objects (XBLs). This sample comprises 19 High-energy cutoff BL Lacs objects (HBLs), 1 Low-energy cutoff BL Lac object (LBL) and 2…

Astrophysics · Physics 2009-10-31 J. A. Stevens , W. K. Gear

Utilizing the latest and the most sensitive radio and optical catalogs, we completed a new blazar candidate catalog, Blazar Radio and Optical Survey (BROS), which includes 88,211 sources located at declination $\delta > -40^{\circ}$ and…

High Energy Astrophysical Phenomena · Physics 2020-08-04 Ryosuke Itoh , Yousuke Utsumi , Yoshiyuki Inoue , Kouji Ohta , Akihiro Doi , Tomoki Morokuma , Koji S. Kawabata , Yasuyuki T. Tanaka

Based on the FIRST and SDSS catalogues a flux density limited sample of weak Compact Steep Spectrum (CSS) sources with radio luminosity below 10^26 [W/Hz] at 1.4 GHz has been constructed. Our previous multifrequency observations of CSS…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-11 Magdalena Kunert-Bajraszewska , Peter Thomasson

At bright radio powers ($P_{\rm 1.4 GHz} > 10^{25}$ W/Hz) the space density of the most powerful sources peaks at higher redshift than that of their weaker counterparts. This paper establishes whether this luminosity-dependent evolution…

Astrophysics of Galaxies · Physics 2015-09-16 E. E. Rigby , J. Argyle , P. N. Best , D. Rosario , H. J. A. Röttgering

Context. The advent of Fermi is changing our understanding on the radio and gamma-ray emission in Active Galactic Nuclei. Contrary to pre-Fermi ideas, BL Lac objects are found to be the most abundant emitters in the gamma-ray band. However,…

High Energy Astrophysical Phenomena · Physics 2015-06-17 E. Liuzzo , M. Giroletti , G. Giovannini , B. Boccardi , S. Tamburri , G. B. Taylor , C. Casadio , M. Kadler , G. Tosti , A. Mignano

This paper presents a detailed analysis of the radio properties for the sample of faint radio sources introduced in Magliocchetti et al. (2000). The sample comprises mainly intrinsically low-power sources whose majority ($\simgt 70$ per…

Astrophysics · Physics 2009-11-07 M. Magliocchetti , A. Celotti , L. Danese

Using three complete, radio flux limited, blazar samples we compare the LogN-LogS and the preliminary radio luminosity function of the general population of BL Lacs to those of the subclass of high energy synchrotron peaked (HBL) BL Lacs.…

Astrophysics · Physics 2007-05-23 P. Giommi , P. Padovani , M. Perri , H. Landt , E. Perlman

The advent of Fermi is changing our understanding on the radio and gamma-ray emission in Active Galactic Nuclei. In fact, contrary to previous campaigns, Fermi mission reveals that BL Lac objects are the most abundant emitters in gamma-ray…

High Energy Astrophysical Phenomena · Physics 2013-06-05 E. Liuzzo , B. Boccardi , M. Giroletti , G. Giovannini

We obtain a sample of 87 radio-loud QSOs in the redshift range 3.6<z<4.4 by cross-correlating sources in the FIRST radio survey S{1.4GHz} > 1 mJy with star-like objects having r <20.2 in SDSS Data Release 7. Of these 87 QSOs, 80 are…

Astrophysics of Galaxies · Physics 2015-06-23 D. Tuccillo , J. I. Gonzalez-Serrano , C. R. Benn

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…