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101. Bright blazars variability brightness temp.
ID:
ivo://CDS.VizieR/J/ApJ/866/137
Title:
Bright blazars variability brightness temp.
Short Name:
J/ApJ/866/137
Date:
21 Oct 2021
Publisher:
CDS
Description:
Relativistic effects dominate the emission of blazar jets complicating our understanding of their intrinsic properties. Although many methods have been proposed to account for them, the variability Doppler factor method has been shown to describe the blazar populations best. We use a Bayesian hierarchical code called Magnetron to model the light curves of 973 sources observed by the Owens Valley Radio Observatory's 40-m telescope as a series of flares with an exponential rise and decay, and estimate their variability brightness temperature. Our analysis allows us to place the most stringent constraints on the equipartition brightness temperature i.e., the maximum achieved intrinsic brightness temperature in beamed sources which we found to be <T_{eq}>=2.78x10^11^K+/-26%. Using our findings we estimated the variability Doppler factor for the largest sample of blazars increasing the number of available estimates in the literature by almost an order of magnitude. Our results clearly show that {gamma}-ray loud sources have faster and higher amplitude flares than {gamma}-ray quiet sources. As a consequence they show higher variability brightness temperatures and thus are more relativistically beamed, with all of the above suggesting a strong connection between the radio flaring properties of the jet and {gamma}-ray emission.
102. Bright extragalactic radio sources at 2.7 GHz
ID:
ivo://CDS.VizieR/J/MNRAS/216/173
Title:
Bright extragalactic radio sources at 2.7 GHz
Short Name:
J/MNRAS/216/173
Date:
21 Oct 2021
Publisher:
CDS
Description:
The brightest extragalactic radio sources at 2.7 GHz are catalogued. The complete sample comprises 233 sources found in the major centimeter wavelength surveys carried out at ANRAO/Parkes, NNRAO/Greenbank, and MPIfR/Bonn: the sample covers 9.81 sr and has limits S(27) = 2.0 Jy and |b| > 10{deg}. A critical reanalysis of the data shows that 227 (97 percent) have optical identifications and 171 (73 percent) have measured redshifts. The implications of the catalogue statistics for the luminosity functions of different radio-source populations are considered.
103. Bright QSOs in Southern Hemisphere (QUBRICS)
ID:
ivo://CDS.VizieR/J/ApJ/887/268
Title:
Bright QSOs in Southern Hemisphere (QUBRICS)
Short Name:
J/ApJ/887/268
Date:
21 Oct 2021
Publisher:
CDS
Description:
The study of absorptions along the lines of sight to bright high-z QSOs is an invaluable cosmological tool that provides a wealth of information on the inter-/circum-galactic medium, dark matter, primordial elements, reionization, fundamental constants, and general relativity. Unfortunately, the number of bright (i<~18) QSOs at z>~2 in the southern hemisphere is much lower than that in the north, due to the lack of wide multiwavelength surveys at decl. {delta}<0{deg}, hampering the effectiveness of observations from southern observatories. In this work we present a new method based on Canonical Correlation Analysis to identify such objects, taking advantage of a number of available databases: Skymapper, Gaia DR2, WISE, and 2MASS. Our QSO candidate sample lists 1476 sources with i<18 over 12400deg^2^ in the southern hemisphere. With a preliminary campaign we observed spectroscopically 69 of them, confirming 54 new bright QSOs at z>2.5, corresponding to a success rate of our method of ~80%. Furthermore, we estimate a completeness of ~90% of our sample at completion of our observation campaign. The new QSOs confirmed by this first and the forthcoming campaigns (QUBRICS survey) will be the targets of subsequent studies using higher resolution spectrographs, like ESPRESSO, UVES, and (in the long term) ELT/HIRES.
104. Bright radio sources at 178 MHz (3CRR)
ID:
ivo://CDS.VizieR/J/MNRAS/204/151
Title:
Bright radio sources at 178 MHz (3CRR)
Short Name:
J/MNRAS/204/151
Date:
21 Oct 2021
Publisher:
CDS
Description:
A revised sample of bright radio sources at 178MHz is defined in order to correct the biases introduced into the 3CR catalog by confusion and partial resolution. The sample is shown to be 96 percent complete to a flux-density limit of 10Jy for sources smaller than 10arcmin. The bias of the 3CR catalog against objects of larger angular size is also reduced. Optical identifications are presented for 96 percent of the sources, 71 percent with galaxies and 25 percent with quasars. The radio-galaxy population is found to show strong space-density evolution for luminosities in excess of approximately 10^26.5^W/Hz/sr at 178MHz (redshifts greater than or approximately equal to 0.2), while the evolutionary properties of galaxies and quasars of the same luminosity and redshift are very similar.
105. Bright southern sub-mm sources
ID:
ivo://CDS.VizieR/J/A+A/376/1123
Title:
Bright southern sub-mm sources
Short Name:
J/A+A/376/1123
Date:
21 Oct 2021
Publisher:
CDS
Description:
Table1 contains the 130 brightest sources of a 230GHz survey of quasars and BL Lacertae objects performed at the SEST. The objects which showed a 230GHz flux density above500 mJy most of the time were selected as pointing sources. Name, coordinates (B1950) and type are given in the table. Due to the variability of many objects the minimum and maximum flux density at 230GHz is given as well. A few values are taken from literature. These data are marked with an asterisk.
106. BRI observations of the QSO Zw III 2
ID:
ivo://CDS.VizieR/J/ApJS/226/17
Title:
BRI observations of the QSO Zw III 2
Short Name:
J/ApJS/226/17
Date:
21 Oct 2021
Publisher:
CDS
Description:
III Zw 2 is the prototype of radio-intermediate quasars. Although there is the evidence of possessing strong jet, significant {gamma}-ray emission has not been reported before. In this work, we carry out a detailed analysis of the latest Fermi-LAT Pass 8 data. No significant {gamma}-ray signal has been detected in the time-averaged 7-year Fermi-LAT data of III Zw 2; however, we have identified two distinct {gamma}-ray flares with isotropic luminosities of ~10^45^erg/s. Multiwavelength data analysis (also including the optical photometric observations from Yunnan Observatories) are presented and the main finding is simultaneous optical and {gamma}-ray flares of III Zw 2 appearing in 2009 November. Violent {gamma}-ray variability with a doubling timescale of 2.5hr was detected in another {gamma}-ray flare in May 2010, for which the 3-hr {gamma}-ray peak flux is ~250 times of the average flux in 7 years. Rather similar behaviors are observed in blazars and the blazar model can reasonably reproduce the spectral energy distribution of III Zw 2 in a wide energy range, strongly suggesting that its central engine resembles that of blazars. In view of its core, which shares radio similarities with young radio sources, together with weak extended radio lobe emission, we suggest that III Zw 2 harbors a recurrent activity core and thus serves as a valuable target for investigating the fueling and triggering of the activity in radio-loud active galactic nuclei.
107. BRI photometry of 3 QSO fields
ID:
ivo://CDS.VizieR/J/AJ/123/2206
Title:
BRI photometry of 3 QSO fields
Short Name:
J/AJ/123/2206
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper describes the acquisition and analysis of imaging data for the identification of galaxies associated with z~4 damped Ly{alpha} systems. We present deep BRI images of three fields known to contain four z~4 damped systems. We discuss the reduction and calibration of the data, detail the color criteria used to identify z~4 galaxies, and present a photometric redshift analysis to complement the color selection. We have found no galaxy candidates closer to the QSO than 7" that could be responsible for the damped Ly{alpha} systems. Assuming that at least one of the galaxies is not directly beneath the QSO, we set an upper limit on this damped Ly {alpha} system of L<L^*^_LBG_/4. Finally, we have established a Web site to release these imaging data to the public, at http://kingpin.ucsd.edu/~dlaimg/papers/refern.html . The observations where made with LRIS on the Keck II telescope, on 13 Jan 1999 for PSS 0132+1341 and BR 0951-0450, and 23 Jan 1999 for PSS 1443+2724.
108. Broad Absorption Line Quasars from SDSS
ID:
ivo://CDS.VizieR/J/AJ/125/1711
Title:
Broad Absorption Line Quasars from SDSS
Short Name:
J/AJ/125/1711
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of 224 broad absorption line quasars (BALQSOs) from the Sloan Digital Sky Survey's Early Data Release Quasar Catalog, (Schneider et al., 2002, Cat. <J/AJ/123/567>) including a relatively complete and homogeneous subsample of 131 BALQSOs. Since the identification of BALQSOs is subject to considerable systematic uncertainties, we attempt to create a complete sample of SDSS BALQSOs by combining the results of two automated selection algorithms and a by-eye classification scheme. One of these automated algorithms finds broad absorption line troughs by comparing with a composite quasar spectrum. We present the details of this algorithm and compare this method with one that uses a power-law fit to the continuum. The BALQSOs in our sample are further classified as high-ionization BALQSOs (HiBALs), low-ionization BALQSOs (LoBALs), and BALQSOs with excited iron absorption features (FeLoBALs); composite spectra of each type are presented. We further present a study of the properties of the BALQSOs in terms of the balnicity distribution, which rises with decreasing balnicity. This distribution of balnicities suggests that the fraction of quasars with intrinsic outflows may be significantly underestimated. The balnicity index defined by Weymann et al. (1991ApJ...373...23W) amounts to a sort of equivalent width: a quasar is declared to be a BAL when its balnicity index is >=0.
109. Broad absorption line quasars in LDR1
ID:
ivo://CDS.VizieR/J/A+A/622/A15
Title:
Broad absorption line quasars in LDR1
Short Name:
J/A+A/622/A15
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a study of the low-frequency radio properties of broad absorption line quasars (BALQSOs) from the LOFAR Two-metre Sky-Survey Data Release 1 (LDR1). The value-added LDR1 catalogue contains Pan-STARRS counterparts, which we match with the Sloan Digital Sky Survey (SDSS) DR7 and DR12 quasar catalogues. We find that BALQSOs are twice as likely to be detected at 144MHz than their non-BAL counterparts, and BALQSOs with low-ionisation species present in their spectra are three times more likely to be detected than those with only high-ionisation species. The BALQSO fraction at 144MHz is constant with increasing radio luminosity, which is inconsistent with previous results at 1.4GHz, indicating that observations at the different frequencies may be tracing different sources of radio emission. We cross-match radio sources between the Faint Images of the Radio Sky at Twenty Centimeters (FIRST) survey and LDR1, which provides a bridge via the LDR1 Pan-STARRS counterparts to identify BALQSOs in SDSS. Consequently we expand the sample of BALQSOs detected in FIRST by a factor of three. The LDR1-detected BALQSOs in our sample are almost exclusively radio-quiet (logr<2), with radio sizes at 144$\,$MHz typically less than 200kpc these radio sizes tend to be larger than those at 1.4GHz, suggesting more extended radio emission at low frequencies. We find that although the radio detection fraction increases with increasing balnicity index (BI), there is no correlation between BI and either low-frequency radio power or radio-loudness. This suggests that both radio emission and BI may be linked to the same underlying process, but are spatially distinct phenomena.
110. Broad HI absorbers
ID:
ivo://CDS.VizieR/J/ApJ/710/613
Title:
Broad HI absorbers
Short Name:
J/ApJ/710/613
Date:
21 Oct 2021
Publisher:
CDS
Description:
We compile a catalog of reliable BLA (thermally broadened Ly{alpha} absorber) candidates along seven active galactic nucleus sight lines from a larger set of Ly{alpha} absorbers observed by the Space Telescope Imaging Spectrograph on the Hubble Space Telescope (HST). We compare our measurements based on independent reduction and analysis of the data to those published by other research groups. We examine the detailed structure of each absorber and determine a reliable line width and column density. Purported BLAs are grouped into probable (15), possible (48), and non-BLA (56) categories. Based on 164 measured curve of growth (COG) HI line measurements, we statistically correct the observed line widths via a Monte Carlo simulation. Finally, we present new, high signal-to-noise ratio observations of several of the BLA candidate lines from Early Release Observations made by the Cosmic Origins Spectrograph on HST.

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