C

Stickel, Eberhard; Groffmann, Hans-Dieter; Rau, Karl-Heinz

doi:10.1007/978-3-663-12126-8_3

Cited by 8 publications

(8 citation statements)

References 4 publications

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“…We searched for the remaining 64 spectra in the NED and found 14 of them in different publications, most of them in Vigotti et al (1997) and Lahulla et al (1991). From these 14, only four could be identified as normal QSOs without BALs: B3 0034+393 with z = 1.94 (Osmer, Porter & Green 1994); B3 0219+443 with z = 0.85 (Djorgovski et al 1990); B3 0249+383 with z = 1.12 (Henstock et al 1997) and B3 2351+456 with z = 2.00 (Stickel & Kühr 1993). The other 10 are difficult to classify because either they are faint, with low signal-to-noise ratio in the continuum (just good enough for a correct redshift identification), or the wavelength coverage does not include the region where the absorbing troughs could be present.…”

Section: Comparison With Non-bal Qsosmentioning

confidence: 99%

Radio spectra and polarization properties of radio-loud broad absorption-line quasars

Montenegro‐Montes

Mack

Vigotti

et al. 2008

Monthly Notices of the Royal Astronomical Society

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We present multifrequency observations of a sample of 15 radio‐emitting broad absorption‐line quasars (BAL QSOs), covering a spectral range between 74 MHz and 43 GHz. They mostly display convex radio spectra which typically peak at about 1–5 GHz (in the observer's rest frame), flatten at MHz frequencies, probably due to synchrotron self‐absorption, and become steeper at high frequencies, i.e. ν≳ 20 GHz. Very Large Array (VLA) 22‐GHz maps (HPBW ∼80 mas) show unresolved or very compact sources, with linear projected sizes of ≤1 kpc. About two‐thirds of the sample looks unpolarized or weakly polarized at 8.4 GHz, frequency in which reasonable upper limits could be obtained for polarized intensity. Statistical comparisons have been made between the spectral index distributions of samples of BAL and non‐BAL QSOs, both in the observed and in the rest frame, finding steeper spectra among non‐BAL QSOs. However, constraining this comparison to compact sources results in no significant differences between both distributions. This comparison is consistent with BAL QSOs not being oriented along a particular line of sight. In addition, our analysis of the spectral shape, variability and polarization properties shows that radio BAL QSOs share several properties common to young radio sources like compact steep spectrum or gigahertz peaked spectrum sources.

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Section: Comparison With Non-bal Qsosmentioning

confidence: 99%

Radio spectra and polarization properties of radio-loud broad absorption-line quasars

Montenegro‐Montes

Mack

Vigotti

et al. 2008

Monthly Notices of the Royal Astronomical Society

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“…Worthy of note is the excellent correspondence between the counter-components to the west of the core region, which are probably images of a weak counterjet. This is intriguing though as the lensed radio source in B0218+357 has been classified as a BL Lac (O'Dea et al 1992;Browne et al 1993;Stickel & Kühr 1993), a class of objects that are not expected to display counterjets according to the unification schemes of extragalactic radio sources. This theoretical prediction is supported by the non-detection of counterjets in BL Lac sources, a notable exception being PKS 1413+135 (Perlman et al 1994(Perlman et al , 1996.…”

Section: Mass Model Constraintsmentioning

confidence: 99%

Global 8.4-GHz VLBI observations of JVAS B0218+357

Biggs

Wucknitz

Porcas

et al. 2003

Monthly Notices of the Royal Astronomical Society

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In this paper we present new observations of the gravitational lens system JVAS B0218+357 made with a global VLBI network at a frequency of 8.4 GHz. Our maps have an rms noise of 30 microJy/beam and with these we have been able to image much of the extended structure of the radio jet in both the A and B images at high resolution (~1 mas). The main use of these maps will be to enable us to further constrain the lens model for the purposes of H0 determination. We are able to identify several sub-components common to both images with the expected parity reversal, including one which we identify as a counter-jet. We have not been successful in detecting either the core of the lensing galaxy or a third image. Using a model of the lensing galaxy we have back-projected both of the images to the source plane and find that they agree well. However, there are small, but significant, differences which we suggest may arise from multi-path scattering in the ISM of the lensing galaxy. We also find an exponent of the radial mass distribution of approximately 1.04, in agreement with lens modelling of published 15-GHz VLBI data. Polarisation maps of each image are presented which show that the distributions of polarisation across images A and B are different. We suggest that this results from Faraday rotation and associated depolarisation in the lensing galaxy.Comment: 10 pages, 5 figures, accepted for publication in MNRA

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“…(Note that all but two 1-Jy BL Lacs have Pmax > 3 per cent , although this was not one of the selection criteria.) We have excluded S5 1053+81 from the sample because its spectrum shows emission lines (Xu et al 1994), and we have added a BL Lac candidate, S5 2353+81 (Stickel & Kühr 1993b). The S5 catalogue is currently being updated by Stickel & Kühr (in preparation).…”

Section: The S5 Samplementioning

confidence: 99%

A Sample-oriented catalogue of BL Lacertae objects

Padovani

Giommi

1995

Monthly Notices of the Royal Astronomical Society

168

130

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We present a catalogue of 233 BL Lacertae objects compiled through an extensive bibliographic search updated to mid-1995. A large fraction of the sources listed in the catalogue belongs to well-defined samples and can be used for statistical purposes. A smaller fraction consists of miscellaneous (but confirmed) BL Lacs and of objects classified as BL Lac candidates. We discuss the selection criteria of the different samples, report the discovery of two previously unnoticed BL Lacs in the Palomar-Green survey, and comment on the possible association of some of the still unidentified high galactic latitude gamma-ray (EGRET) sources with BL Lacs. Some statistical properties of the catalogue are also briefly discussed.

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C

Cited by 8 publications

References 4 publications

Radio spectra and polarization properties of radio-loud broad absorption-line quasars

Radio spectra and polarization properties of radio-loud broad absorption-line quasars

Global 8.4-GHz VLBI observations of JVAS B0218+357

A Sample-oriented catalogue of BL Lacertae objects

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