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941. The Hamburg Quasar Survey. II.
ID:
ivo://CDS.VizieR/J/A+AS/128/507
Title:
The Hamburg Quasar Survey. II.
Short Name:
J/A+AS/128/507
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Hamburg Quasar Survey is a wide-angle objective prism survey for finding bright QSOs in the northern extragalactic sky (|b|>20{deg}; {delta}>0{deg}). The taking of the prism plates for 567 fields covering this area was completed in 1997. Including direct plates for fields with {delta}> 20{deg} the plate archive contains now 1871 plates. In this paper we present a first list of 121 quasars, which were verified by slit spectroscopy in the years 1986-1991, while experiments to develop efficient selection techniques were made. The sample contains objects with brightnesses 15<=B<=19.5 and redshifts z<=2.8 collected over various parts of the sky, for which objective prism plates were available at that time.
942. The Hamburg Quasar Survey. III.
ID:
ivo://CDS.VizieR/J/A+AS/134/483
Title:
The Hamburg Quasar Survey. III.
Short Name:
J/A+AS/134/483
Date:
21 Oct 2021
Publisher:
CDS
Description:
Table 3 lists for all new QSOs the position for equinox 2000.0 with an accuracy ~2", the B magnitude obtained from the Schmidt plates with an accuracy ~<0.5 (see Paper I, Hagen et al., 1995A&AS..111..195H), the redshift, and the number of the campaign of Table 2 in which the data were obtained.
943. The high-redshift COBRA survey: IRAC obs.
ID:
ivo://CDS.VizieR/J/ApJ/844/78
Title:
The high-redshift COBRA survey: IRAC obs.
Short Name:
J/ApJ/844/78
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present 190 galaxy cluster candidates (most at high redshift) based on galaxy overdensity measurements in the Spitzer/IRAC imaging of the fields surrounding 646 bent, double-lobed radio sources drawn from the Clusters Occupied by Bent Radio AGN (COBRA) Survey. The COBRA sources were chosen as objects in the Very Large Array FIRST survey that lack optical counterparts in the Sloan Digital Sky Survey to a limit of m_r_=22, making them likely to lie at high redshift. This is confirmed by our observations: the redshift distribution of COBRA sources with estimated redshifts peaks near z=1 and extends out to z~3. Cluster candidates were identified by comparing our target fields to a background field and searching for statistically significant (>=2{sigma}) excesses in the galaxy number counts surrounding the radio sources; 190 fields satisfy the >=2{sigma} limit. We find that 530 fields (82.0%) have a net positive excess of galaxies surrounding the radio source. Many of the fields with positive excesses but below the 2{sigma} cutoff are likely to be galaxy groups. Forty-one COBRA sources are quasars with known spectroscopic redshifts, which may be tracers of some of the most distant clusters known.
944. The MgII cross-section of red galaxies
ID:
ivo://CDS.VizieR/J/ApJ/727/47
Title:
The MgII cross-section of red galaxies
Short Name:
J/ApJ/727/47
Date:
21 Oct 2021
Publisher:
CDS
Description:
We describe a search for MgII(2796, 2803) absorption lines in Sloan Digital Sky Survey (SDSS) spectra of QSOs whose lines of sight pass within impact parameters {rho}~200kpc of galaxies with photometric redshifts of z=0.46-0.6 and errors {Delta}z~0.05. The galaxies selected have the same colors and luminosities as the Luminous Red Galaxy (LRG) population previously selected from the SDSS. A search for MgII lines within a redshift interval of +/-0.1 of a galaxy's photometric redshift shows that absorption by these galaxies is rare: the covering fraction is f({rho})~10%-15% between {rho}=20kpc and {rho}=100kpc, for MgII lines with rest equivalent widths of W_r_>=0.6{AA}, falling to zero at larger {rho}. There is no evidence that W_r_ correlates with impact parameter or galaxy luminosity.
945. The Million Quasars (Milliquas) catalog
ID:
ivo://CDS.VizieR/VII/277
Title:
The Million Quasars (Milliquas) catalog
Short Name:
VII/277
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is a compendium of 452,794 type-I QSOs and AGN, largely complete from the literature to 21 June 2016. Also included are ~900K high-confidence quasar candidates from SDSS-based photometric quasar catalogs (of 90%+ likelihood) and from all-sky radio/X-ray associated objects (of 80%+ likelihood). Type-II and Bl Lac objects are also included, bringing the total count to 1,422,219. This version is the same as v4.8 but with these changes: (1) The 3XMM-DR6 X-ray source catalog (www.cosmos.esa.int/web/xmm-newton/xsa) has been added and new X-ray associations calculated. (2) Radio/X-ray data have been reprocessed in line with that of the new Million Optical Radio/X-ray (MORX) associations catalogue, in preparation. The catalog format is simple, each object is shown as one line bearing the J2000 coordinates, its original name, object class, red and blue optical magnitudes, PSF class, redshift, the citations for the name and redshift, plus up to four radio/X-ray identifiers where applicable. Questions/comments/praise/complaints may be directed to Eric Flesch at eric(at)flesch.org.
946. The Million Quasars (Milliquas) catalog (6.3)
ID:
ivo://CDS.VizieR/VII/283
Title:
The Million Quasars (Milliquas) catalog (6.3)
Short Name:
VII/283
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is a compendium of 623,004 type-I QSOs and AGN, largely complete from the literature to 15 June 2019 including SDSS-DR15 and LAMOST QSO DR5. Also included are approx 1.32M high-confidence (80%+ likelihood) quasar candidates from the NBCKDE, NBCKDE-v3, AllWISE, XDQSO & Peters photometric quasar catalogs (citations in Note 7 below) and from all-sky radio/X-ray associated objects which are calculated here. Type-II and Bl Lac objects are also included, plus galaxies with double radio lobes, bringing the total count to 1,986,800. Gaia-DR2 astrometry is used where available, amounting to ~63% of all objects. Changes from version 6.2 are: (1) Quasars added from publications to 15 June 2019, including 4LAC. (2) 3581 galaxies with double radio lobes are added as type=G because the lobes show that they have active nuclei of some kind, even if well hidden. (3) Positional fixes of a few arcsec were done for ~50 legacy objects. (4) Blazar candidates with neither redshift nor radio/X-ray association, about 30 objects, are dropped. Most were stated low confidence in legacy papers. Low-confidence/quality or questionable objects (so deemed by their researchers) are not included in Milliquas. Additional quality cuts can be applied as detailed in Flesch 2015,PASA,32,10. The aim here is to present one unique reliable object per each data row. The catalog format is simple, each object is shown as one line bearing the J2000 coordinates, its original name, object class, red and blue optical magnitudes, PSF class, redshift, the citations for the name and redshift, plus up to four radio/X-ray identifiers where applicable. This catalog can be cited as Milliquas v6.3 2019 update, Flesch E., 2015PASA...32...10F was the published version of this catalog as at 2015. Questions/comments/praise/complaints may be directed to me at eric(at)flesch.org.
947. The Million Quasars (Milliquas) catalogue, version 7.2
ID:
ivo://CDS.VizieR/VII/290
Title:
The Million Quasars (Milliquas) catalogue, version 7.2
Short Name:
VII/290
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is a compendium of 829666 type-I QSOs and AGN, largely complete from the literature to 30 April 2021 including SDSS-DR16 quasars and VLASS radio. Also included are 703348 candidates which are calculated as 60%-100% likely to be quasars, including 225051 which are radio/X-ray associated. Type-II and Bl Lac objects are also included, bringing the total count to 1573824. Gaia-DR2 astrometry is used where available, amounting to ~66% of all objects. Changes from version 7.1 are: (1) Quasars added from publications to 30 April 2021. (2) The VLASS Quick Look radio catalog is included, which adds 34189 new radio core associations and 6793 probable double radio lobe associations. (3) Ongoing audits of SDSS & LAMOST quasars have led to a few additions & drops. Some WISEA-supported SDSS/LAMOST pipeline quasars are now accepted which were otherwise marginal. Also some likely galaxies removed. Low-confidence/quality or questionable objects (so deemed by their researchers) are not included in Milliquas. Additional quality cuts can apply as detailed in the HMQ paper (Flesch, 2015PASA...32...10F). Full QSO/AGN classification is via spectral lines, thus hidden / occluded objects may be absent from Milliquas. Two NIQs offset <2-arcsecs can be reported as a single object if within the same host. The aim here is to present one unique reliable object per each data row. The catalog format is simple, each object is shown as one line bearing the J2000 coordinates, its original name, object class, red and blue optical magnitudes, PSF class, redshift, the citations for the name and redshift, plus up to four radio/X-ray identifiers where applicable. Please cite as Milliquas v7.2, Flesch, E.W. 2021, arXiv:2105.12985 or as Milliquas v7.2 (2021) update, Flesch, E.W. 2015PASA...32...10F. Questions/comments/praise/complaints may be directed to me at eric(at)flesch.org.
948. The Million Quasars (Milliquas) catalog (V5.2)
ID:
ivo://CDS.VizieR/VII/280
Title:
The Million Quasars (Milliquas) catalog (V5.2)
Short Name:
VII/280
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is a compendium of 607,208 type-I QSOs and AGN, largely complete from the literature to 5-August-2017, including the release of SDSS-DR14. Also included are ~1.35M high-confidence (80%+ likelihood) quasar candidates from the NBCKDE, NBCKDE-v3, XDQSO, AllWISE and Peters photometric quasar catalogs (citations in Note 7 below) and from all-sky radio/X-ray associated objects which are calculated here. Type-II and Bl Lac objects are also included, bringing the total count to 1,998,464. Changes from version 5.1 are: (1) SDSS-DR14 and SDSS-DR14Q have been added, using the processing rules from the Half Million Quasars catalog (HMQ: Flesch 2015PASA...32...10F). (2) WISE quasar candidates have been added from Secrest et al, 2015, Cat. J/ApJS/221/12; these are ~430K candidates over the whole sky for which 2-color optical objects were found within a 2-arcsec radius. They have been processed into pQSOs from calibration against the SDSS-DR12Q multi-class superset, and photometric redshifts obtained using the four-color based method from the HMQ appendix 2. The four colors used were B-R, R-W1, W1-W2 & W2-W3. (3) Type-II narrow emission-line galaxies, (NELGs, class='N') are added as the luminosity class corresponding to the type-I AGN galaxies. High-luminosity type-II NLAGN (class='K') correspond to the type-I quasars. The NLAGN/NELG divider is the same luminosity/psf function which separates QSOs from AGNs. Type-II NELGs include unquantified contamination by LINERs and probably a few starbursts which eluded removal, so it serves as a catch-all category presented for completeness, rather than as a strict type-II class. (4) Small publications to 5 August 2017 have been added. (5) Positional fixes (of about 2 arcsec) have been applied to ~150 objects. Low-confidence or questionable objects (so deemed by their researchers) are not included in Milliquas. Additional quality cuts can be applied as detailed in Flesch 2015PASA...32...10F). Multiple lensed images are excluded and only the brightest one kept. The aim here is to present one unique reliable object per each data row. The catalog format is simple, each object is shown as one line bearing the J2000 coordinates, its original name, object class, red and blue optical magnitudes, PSF class, redshift, the citations for the name and redshift, plus up to four radio/X-ray identifiers where applicable. This catalog can be cited as Milliquas, Flesch E., 2015PASA...32...10F which was the published version of this catalog as at 2015 after the release of SDSS-DR12. Questions/comments/praise/complaints may be directed to me at eric(at)flesch.org.
949. The multi-component absorber QSO 0318-0600
ID:
ivo://CDS.VizieR/J/ApJ/709/611
Title:
The multi-component absorber QSO 0318-0600
Short Name:
J/ApJ/709/611
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present high spectral resolution Very Large Telescope observations of the broad absorption line quasar SDSS J0318-0600. This high-quality data set allows us to extract accurate ionic column densities and determine an electron number density of n_e_=10^3.3+/-0.2^cm^-3^ for the main outflow absorption component. The heavily reddened spectrum of SDSS J0318-0600 requires purely silicate dust with a reddening curve characteristic of predominately large grains, from which we estimate the bolometric luminosity. We carry out photoionization modeling to determine the total column density, ionization parameter, and distance of the gas and find that the photoionization models suggest abundances greater than solar. Due to the uncertainty in the location of the dust extinction, we arrive at two viable distances for the main ouflow component from the central source, 6 and 17kpc, where we consider the 6kpc location as somewhat more physically plausible. Assuming the canonical global covering of 20% for the outflow and a distance of 6kpc, our analysis yields a mass flux of 120M_{sun}_/yr and a kinetic luminosity that is ~0.1% of the bolometric luminosity of the object. Should the dust be part of the outflow, then these values are ~4x larger. The large mass flux and kinetic luminosity make this outflow a significant contributor to active galactic nucleus feedback processes.
950. The MWA view of Fermi blazars
ID:
ivo://CDS.VizieR/J/A+A/588/A141
Title:
The MWA view of Fermi blazars
Short Name:
J/A+A/588/A141
Date:
21 Oct 2021
Publisher:
CDS
Description:
Low-frequency radio arrays are opening a new window for the study of the sky, both to study new phenomena and to better characterize known source classes. Being flat-spectrum sources, blazars are so far poorly studied at low radio frequencies. We characterize the spectral properties of the blazar population at low radio frequency, compare the radio and high-energy properties of the gamma-ray blazar population, and search for radio counterparts of unidentified gamma-ray sources. We cross-correlated the 6100-deg^2^ Murchison Widefield Array Commissioning Survey catalogue with the Roma blazar catalogue, the third catalogue of active galactic nuclei detected by Fermi-LAT, and the unidentified members of the entire third catalogue of gamma-ray sources detected by Fermi-LAT. When available, we also added high-frequency radio data from the Australia Telescope 20GHz catalogue.