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- ID:
- ivo://CDS.VizieR/VII/11
- Title:
- Kitt Peak Quasar List
- Short Name:
- VII/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog includes the complete source list with positions of the Kitt Peak Quasar Catalog (de Veny et al., 1971PASP...83..611D). Other fields in the de Veny catalog (4C ID, B1950 equatorial positions, V, B-V, U-B, z, references to ID UBV z, and Notes and other references) are not included. The Kitt Peak Quasar Catalog sources were selected based on optical data for all confirmed quasars published prior to May or June 1971. This includes objects with only one spectral line. The published catalog includes a bibliography for all quasars with redshifts The source list also includes some additional sources included by the author.
- ID:
- ivo://CDS.VizieR/J/AJ/131/1923
- Title:
- Known quasars in the QUEST Variability Survey
- Short Name:
- J/AJ/131/1923
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present variability and multiwavelength photometric information for the 933 known quasars in the QUEST Variability Survey (Cat. <II/266>). These quasars are grouped into variable and nonvariable populations based on measured variability confidence levels.
394. KODIAQ DR2
- ID:
- ivo://CDS.VizieR/J/AJ/154/114
- Title:
- KODIAQ DR2
- Short Name:
- J/AJ/154/114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and make publicly available the second data release (DR2) of the Keck Observatory Database of Ionized Absorption toward Quasars (KODIAQ) survey. KODIAQ DR2 consists of a fully reduced sample of 300 quasars at 0.07<z_em_<5.29 observed with HIRES at high resolution (36000{<=}R{<=}103000). DR2 contains 831 spectra available in continuum normalized form, representing a sum total exposure time of ~4.9 megaseconds on source. These co-added spectra arise from a total of 1577 individual exposures of quasars taken from the Keck Observatory Archive (KOA) in raw form and uniformly processed. DR2 extends DR1 by adding 130 new quasars to the sample, including additional observations of QSOs in DR1. All new data in DR2 were obtained with the single-chip Tektronix TK2048 CCD configuration of HIRES in operation between 1995 and 2004. DR2 is publicly available to the community, housed as a higher level science product at the KOA and in the igmspec database (v03).
395. KODIAQ DR1
- ID:
- ivo://CDS.VizieR/J/AJ/150/111
- Title:
- KODIAQ DR1
- Short Name:
- J/AJ/150/111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and make publicly available the first data release (DR1) of the Keck Observatory Database of Ionized Absorption toward Quasars (KODIAQ) survey. The KODIAQ survey is aimed at studying galactic and circumgalactic gas in absorption at high redshift, with a focus on highly ionized gas traced by O vi, using the HIRES spectrograph on the KeckI telescope. KODIAQ DR1 consists of a fully reduced sample of 170 quasars at 0.29<z_em_<5.29 observed with HIRES at high resolution (36000{<=}R{<=}103000) between 2004 and 2012. DR1 contains 247 spectra available in continuum normalized form, representing a sum total exposure time of ~1.6 megaseconds. These coadded spectra arise from a total of 567 individual exposures of quasars taken from the Keck Observatory Archive (KOA) in raw form and uniformly processed using a publicly available HIRES data reduction package. DR1 is publicly available to the community, housed as a higher level science product at the KOA. We will provide future data releases that make available additional quasars, including those with pre-2004 observations taken with the previous-generation HIRES detectors.
- ID:
- ivo://CDS.VizieR/J/AJ/161/45
- Title:
- KODIAQ DR3: 727 quasars (01.<zem<6.4) with ESI
- Short Name:
- J/AJ/161/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and make publicly available the third data release (DR3) of the Keck Observatory Database of Ionized Absorption toward Quasars (KODIAQ) survey. KODIAQ DR3 consists of a fully reduced sample of 727 quasars at 0.1<zem<6.4 observed with the Echellette Sepctrograph and Imager at moderate resolution (4000<~R<~10000). DR3 contains 872 spectra available in flux calibrated form, representing a sum total exposure time of ~2.8 megaseconds. These coadded spectra arise from a total of 2753 individual exposures of quasars taken from the Keck Observatory Archive (KOA) in raw form and uniformly processed using a data reduction package made available through the XIDL distribution. DR3 is publicly available to the community, housed as a higher level science product at the KOA and in the igmspec database.
- ID:
- ivo://CDS.VizieR/J/A+A/541/A77
- Title:
- Kohonen-selected unusual SDSS quasars
- Short Name:
- J/A+A/541/A77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Large spectroscopic surveys have discovered very peculiar and hitherto unknown types of active galactic nuclei (AGN). Such rare objects may hold clues to the accretion history of the supermassive black holes at the centres of galaxies. We aim to create a sizeable sample of unusual quasars from the unprecedented spectroscopic database of the Sloan Digital Sky Survey (SDSS).
- ID:
- ivo://CDS.VizieR/J/ApJ/528/123
- Title:
- KRI photometry of galaxies near B2 1335+28
- Short Name:
- J/ApJ/528/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We previously reported a significant clustering of red galaxies (R-K=3.56) around the radio-loud quasar B2 1335+28 at z=1.086. In this paper, we establish the existence of a rich cluster at the quasar redshift and study the properties of the cluster galaxies through further detailed analysis of the photometric data. We also list the positions, K-band magnitudes, and colors of all K<19 objects. The near-infrared (NIR) K-band imaging data presented in earlier paper, together with some additional K-band data, is newly analyzed to study the extent of the clustering of the red galaxies. We also constrain the cluster redshift by applying a robust photometric redshift estimator and find a strong peak around z=1.1. The color distribution of the galaxies in the cluster is quite broad, and the fraction of blue galaxies (70%) is much larger than in intermediate-redshift clusters.
399. KX redshift survey
- ID:
- ivo://CDS.VizieR/J/MNRAS/328/150
- Title:
- KX redshift survey
- Short Name:
- J/MNRAS/328/150
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present preliminary spectroscopic results from a small-area faint K-excess (KX) survey, and compare KX selection against UVX selection. The aim of the KX method is to produce complete samples of QSOs that are flux-limited in the K band, in order to minimize any selection bias in samples of QSOs from the effects of reddening and extinction. Using the photometric catalogue of the ESO Imaging Survey Chandra Deep Field South (48arcmin^2^) we have identified compact objects with J-K colours redder than the stellar sequence that are brighter than K=19.5. We have obtained spectra of 33 candidates, using the LDSS++ spectrograph on the Anglo-Australian Telescope (AAT). Amongst the 11 bluer candidates, with V-J<3, three are confirmed as QSOs. Identification of the 22 redder candidates with V-J>=3 is substantially incomplete, but so far no reddened QSOs have been found. Near-infrared spectroscopy will be more effective in identifying some of these targets. Only two UVX (U-B<-0.2) sources brighter than K=19.5 are found that are not also KX selected. These are both identified as galactic stars. Thus KX selection appears to select all UVX QSOs. The surface density of QSOs in the blue subsample (V-J<3) at K<=19.5 is 325^+136^_-177_{deg}^-2^. Because identification of the red subsample (V-J>=3) is substantially incomplete, the 2{sigma} upper limit on the density of reddened QSOs is large, <1150{deg}^-2^. As anticipated, at these faint magnitudes the KX sample includes several compact galaxies. Of the 14 with measured redshifts, there are roughly equal numbers of early- and late-type objects. Nearly all the early-type galaxies are found in a single structure at z=0.66.
- ID:
- ivo://CDS.VizieR/J/ApJ/818/30
- Title:
- Lag measurements for 15 z<0.8 QSOs from the SDSS-RM
- Short Name:
- J/ApJ/818/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Reverberation mapping (RM) measurements of broad-line region (BLR) lags in z>0.3 quasars are important for directly measuring black hole masses in these distant objects, but so far there have been limited attempts and success given the practical difficulties of RM in this regime. Here we report preliminary results of 15 BLR lag measurements from the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project, a dedicated RM program with multi-object spectroscopy designed for RM over a wide redshift range. The lags are based on the 2014 spectroscopic light curves alone (32 epochs over six months) and focus on the H{beta} and Mg II broad lines in the 100 lowest-redshift (z<0.8) quasars included in SDSS-RM; they represent a small subset of the lags that SDSS-RM (including 849 quasars to z~4.5) is expected to deliver. The reported preliminary lag measurements are for intermediate-luminosity quasars at 0.3<~z<0.8, including nine H{beta} lags and six Mg II lags, for the first time extending RM results to this redshift-luminosity regime and providing direct quasar black hole mass estimates over approximately half of cosmic time. The Mg II lags also increase the number of known Mg II lags by several fold and start to explore the utility of Mg II for RM at high redshift. The location of these new lags at higher redshifts on the observed BLR size-luminosity relationship is statistically consistent with previous H{beta} results at z<0.3. However, an independent constraint on the relationship slope at z>0.3 is not yet possible owing to the limitations in our current sample. Our results demonstrate the general feasibility and potential of multi-object RM for z>0.3 quasars.
