The 5-GHz strong source surveys. V - Survey of the area between declinations 70 and 90 deg

Kuehr, H.; Pauliny-Toth, I. I. K.; Witzel, A.; Schmidt, Johannes

doi:10.1086/112957

Cited by 161 publications

(114 citation statements)

References 0 publications

Supporting

Mentioning

110

Contrasting

Unclassified

Order By: Relevance

“…-J1419+5423. This is the most powerful object in the sample, and it is also the best studied, being in the BL Lac 1 Jy sample (Kuehr et al 1981). It is an extremely peculiar (see Sect.…”

Section: Discussionmentioning

confidence: 97%

Exploring the bulk of the BL Lacertae object population

Liuzzo

Giroletti

Giovannini

et al. 2013

A&A

View full text Add to dashboard Cite

Context. The advent of Fermi is changing our understanding on the radio and γ-ray emission in active galactic nuclei. Unlike preFermi ideas, BL Lac objects are found to be the most abundant emitters in the γ-ray band. However, since they are relatively weak radio sources, most of their parsec-scale structure and their multifrequency properties are poorly understood and/or have not been investigated in a systematic fashion. Aims. Our main goal is to analyze the radio and γ-ray emission properties of a sample of 42 BL Lacs selected, for the first time in the literature, with no constraint on their radio and γ-ray emission. Methods. Thanks to new Very Long Baseline Array observations at 8 and 15 GHz for the whole sample, we present fundamental parameters here such as radio flux densities, spectral index information, and parsec-scale structure. Moreover, we search for γ-ray counterparts using data reported in the Second Catalog of Fermi Gamma-ray sources. Results. Parsec-scale radio emission is observed in the majority of the sources at both frequencies. Gamma-ray counterparts are found for 14/42 sources. Conclusions. The comparison between our results in radio and gamma-ray bands points out the presence of a large number of faint BL Lacs showing "non-classical" properties such as low source compactness, core dominance, no gamma-ray emission, and steep radio spectral indexes. A deeper multiwavelength analysis will be needed.

show abstract

“…-J1419+5423. This is the most powerful object in the sample, and it is also the best studied, being in the BL Lac 1 Jy sample (Kuehr et al 1981). It is an extremely peculiar (see Sect.…”

Section: Discussionmentioning

confidence: 97%

Exploring the bulk of the BL Lacertae object population

Liuzzo

Giroletti

Giovannini

et al. 2013

A&A

View full text Add to dashboard Cite

show abstract

“…(7) and (8) give the calculated spectral indices between 1.4 and 5 GHz (α 5 1.4 taken from Taylor et al 1996), and between 5 and 30 GHz (α 30 5 ); Col. (9) indicates the VLBI morphology where c = compact, cj = core-jet, d = double, cso = compact symmetric object, mso = medium symmetric object, t = triple, g = gravitational lens. Kuehr et al (1981). b These identifications were made by Rossetti et al (2005).…”

Section: Discussionmentioning

confidence: 99%

30 GHz flux density measurements of the Caltech-Jodrell flat-spectrum sources with OCRA-p

Lowe¹,

Gawroński

Wilkinson³

et al. 2007

A&A

View full text Add to dashboard Cite

Aims. To measure the 30-GHz flux densities of the 293 sources in the Caltech-Jodrell Bank flat-spectrum (CJF) sample. The measurements are part of an ongoing programme to measure the spectral energy distributions of flat spectrum radio sources and to correlate them with the milliarcsecond structures from VLBI and other measured astrophysical properties. Methods. The 30-GHz data were obtained with a twin-beam differencing radiometer system mounted on the Toruń 32-m telescope. The system has an angular resolution of 1.2 . Results. Together with radio spectral data obtained from the literature, the 30-GHz data have enabled us to identify 42 of the CJF sources as Giga-hertz Peaked Spectrum (GPS) sources. Seventeen percent of the sources have rising spectra (α > 0) between 5 and 30 GHz.

show abstract

“…A source known to be linearly polarised at a level > 5% across the range from 10-30 cm wavelengths (Gardner & Davies 1966), it was also included in the Kuehr et al (1981) sample based on its 5 GHz flux density being > 1 Jy. It was imaged at 2 resolution by Duncan & Sproats (1992) revealing a doublelobed structure and central radio source.…”

Section: Pks 1547−79mentioning

confidence: 99%

Connecting X-ray absorption and 21 cm neutral hydrogen absorption in obscured radio AGN

Moss

Allison

Sadler

et al. 2017

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Many radio galaxies show the presence of dense and dusty gas near the active nucleus. This can be traced by both 21 cm Hi absorption and soft X-ray absorption, offering new insight into the physical nature of the circumnuclear medium of these distant galaxies. To better understand this relationship, we investigate soft X-ray absorption as an indicator for the detection of associated Hi absorption, as part of preparation for the First Large Absorption Survey in Hi (FLASH) to be undertaken with the Australian Square Kilometre Array Pathfinder (ASKAP). We present the results of our pilot study using the Boolardy Engineering Test Array, a precursor to ASKAP, to search for new absorption detections in radio sources brighter than 1 Jy that also feature soft X-ray absorption. Based on this pilot survey, we detected Hi absorption towards the radio source PKS 1657−298 at a redshift of z = 0.42. This source also features the highest X-ray absorption ratio of our pilot sample by a factor of 3, which is consistent with our general findings that X-ray absorption predicates the presence of dense neutral gas. By comparing the X-ray properties of AGN with and without detection of Hi absorption at radio wavelengths, we find that X-ray hardness ratio and Hi absorption optical depth are correlated at a statistical significance of 4.71σ. We conclude by considering the impact of these findings on future radio and X-ray absorption studies.

show abstract

The 5-GHz strong source surveys. V - Survey of the area between declinations 70 and 90 deg

Cited by 161 publications

References 0 publications

Exploring the bulk of the BL Lacertae object population

Exploring the bulk of the BL Lacertae object population

30 GHz flux density measurements of the Caltech-Jodrell flat-spectrum sources with OCRA-p

Connecting X-ray absorption and 21 cm neutral hydrogen absorption in obscured radio AGN

Contact Info

Product

Resources

About