A catalogue of quasars and active nuclei: 13th edition

Véron-Cetty, M. P.; Véron, Philippe

doi:10.1051/0004-6361/201014188

Cited by 659 publications

(306 citation statements)

References 75 publications

Supporting

Mentioning

294

Contrasting

Unclassified

Order By: Relevance

“…The measured optical flux density of this knot at 4.97 × 10 14 Hz is 2.5 ± 0.2 µJy (Worrall et al 2012). This is strikingly similar to the value of the residual flux in the V optical band which is 2.4 ± 0.1 µJy (using the apparent magnitude mV = 17.34 of Q 0528−250, Véron-Cetty & Véron (2010)). The variability of a jet emission (during from a few days up to a month) should be high and should also induce variability of the residual flux in the H2 line.…”

Section: Jet-cloud Interactionsupporting

confidence: 77%

Partial covering of the emission regions of Q 0528−250 by intervening H2 clouds

Клименко

Balashev

Ivanchik

et al. 2015

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We present an analysis of the molecular hydrogen absorption system at z abs = 2.811 in the spectrum of the blazar Q 0528−250. We demonstrate that the molecular cloud does not cover the background source completely. The partial coverage reveals itself as a residual flux in the bottom of saturated H 2 absorption lines. This amounts to about (2.22 ± 0.54)% of the continuum and does not depend on the wavelength. This value is small and it explains why this effect has not been detected in previous studies of this quasar spectrum. However, it is robustly detected and significantly higher than the zero flux level in the bottom of saturated lines of the Lyα forest, (−0.21 ± 0.22) per cent. The presence of the residual flux could be caused by unresolved quasar multicomponents, by light scattered by dust, and/or by jet-cloud interaction. The H 2 absorption system is very well described by a two-component model without inclusion of additional components when we take partial coverage into account. The derived total column densities in the H 2 absorption components A and B are log N (H 2 )[cm −2 ] = 18.10±0.02 and 17.82 ± 0.02, respectively. HD molecules are present only in component B. Given the column density, log N (HD) = 13.33 ± 0.02, we find N (HD)/ 2N (H 2 ) = (1.48 ± 0.10) × 10 −5 , significantly lower than previous estimations. We argue that it is crucial to take into account the partial coverage effects in any analysis of H 2 bearing absorption systems, in particular when studying the physical state of high-redshift interstellar medium.

show abstract

Section: Jet-cloud Interactionsupporting

confidence: 77%

Partial covering of the emission regions of Q 0528−250 by intervening H2 clouds

Клименко

Balashev

Ivanchik

et al. 2015

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…The mean separation on the sky of VMC counterparts for quasars from Dobrzycki et al (2002Dobrzycki et al ( , 2003aDobrzycki et al ( ,b, 2005, Kozłowski et al (2011) andVéron-Cetty &Véron (2010) are very similar and correspond to 0.64 ± 0.30 . The larger separation of VMC counterparts to the quasars from Kozłowski et al (2011) compared to the quasars from Kozłowski et al (2012) is most likely due to their identification from the OGLE database part II in one case and part III in the other.…”

Section: A3 Vmc-qso Counterpartsmentioning

confidence: 87%

The VMC Survey

Cioni¹,

Kamath²,

Rubele³

et al. 2012

A&A

View full text Add to dashboard Cite

Context. The number and spatial distribution of confirmed quasi-stellar objects (QSOs) behind the Magellanic system is limited. This undermines their use as astrometric reference objects for different types of studies. Aims. We have searched for criteria to identify candidate QSOs using observations from the VISTA survey of the Magellanic Clouds system (VMC) that provides photometry in the Y JK s bands and 12 epochs in the K s band. Methods. The (Y − J) versus (J − K s ) diagram has been used to distinguish QSO candidates from Milky Way stars and stars of the Magellanic Clouds. Then, the slope of variation in the K s band has been used to identify a sample of high confidence candidates. These criteria were developed based on the properties of 117 known QSOs presently observed by the VMC survey. Results. VMC Y JK s magnitudes and K s light-curves of known QSOs behind the Magellanic system are presented. About 75% of them show a slope of variation in K s > 10 −4 mag/day and the shape of the light-curve is in general irregular and without any clear periodicity. The number of QSO candidates found in tiles including the south ecliptic pole and the 30 Doradus regions is 22 and 26, respectively, with a ∼20% contamination by young stellar objects, planetary nebulae, stars and normal galaxies. Conclusions. By extrapolating the number of QSO candidates to the entire VMC survey area we expect to find about 1200 QSOs behind the LMC, 400 behind the SMC, 200 behind the Bridge and 30 behind the Stream areas, but not all will be suitable for astrometry. Further, the K s band light-curves can help support investigations of the mechanism responsible for the variations.

show abstract

“…There is now available a more recent version of the VCV catalog [33]. Conclusions are similar if the arrival directions are compared to the distribution of objects in this latest version.…”

Section: Periodmentioning

confidence: 96%

Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

Abreu

Aglietta

Ahn

et al. 2010

Astroparticle Physics

281

210

View full text Add to dashboard Cite

a b s t r a c tData collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuz'min energy threshold, 6 Â 10 19 eV. The anisotropy was measured by the fraction of arrival directions that are less than 3.1°from the position of an active galactic nucleus within 75 Mpc (using the Véron-Cetty and Véron 12th catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is 38 þ7 À6 %, compared with 21% expected for isotropic cosmic rays. This is down from the early estimate of 69 þ11 À13 %.1 Deceased.

show abstract

A catalogue of quasars and active nuclei: 13th edition

Cited by 659 publications

References 75 publications

Partial covering of the emission regions of Q 0528−250 by intervening H2 clouds

Partial covering of the emission regions of Q 0528−250 by intervening H2 clouds

The VMC Survey

Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

Contact Info

Product

Resources

About