- ID:
- ivo://CDS.VizieR/J/MNRAS/468/77
- Title:
- Sample of confirmed quasar pairs
- Short Name:
- J/MNRAS/468/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the most precise estimate to date of the clustering of quasars on very small scales, based on a sample of 47 binary quasars with magnitudes of g < 20.85 and proper transverse separations of ~25h^-1^kpc. Our sample of binary quasars, which is about six times larger than any previous spectroscopically confirmed sample on these scales, is targeted using a kernel density estimation (KDE) technique applied to Sloan Digital Sky Survey (SDSS) imaging over most of the SDSS area. Our sample is 'complete' in that all of the KDE target pairs with 17.0<=R<=36.2h^-1^kpc in our area of interest have been spectroscopically confirmed from a combination of previous surveys and our own long-slit observational campaign. We catalogue 230 candidate quasar pairs with angular separations of <8 arcsec, from which our binary quasars were identified. We determine the projected correlation function of quasars (<W>_ p_) in four bins of proper transverse scale over the range 17.0<=R<=36.2h^-1^kpc. The implied small-scale quasar clustering amplitude from the projected correlation function, integrated across our entire redshift range, is A=24.1+/-3.6 at ~26.6h^-1^kpc. Our sample is the first spectroscopically confirmed sample of quasar pairs that is sufficiently large to study how quasar clustering evolves with redshift at ~25h^-1^kpc. We find that empirical descriptions of how quasar clustering evolves with redshift at ~25h^-1^Mpc also adequately describe the evolution of quasar clustering at ~25h^-1^kpc.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/448/579
- Title:
- Sample of confirmed WDs in GSC-II survey
- Short Name:
- J/A+A/448/579
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The GSC-II white dwarf survey was designed to identify faint and high proper motion objects, which we used to define a new and independent sample of cool white dwarfs. With this survey we aim to derive new constraints on the halo white dwarf space density. Also, these data can provide information on the age of thick disk and halo through the analysis of the luminosity function. On the basis of astrometric and photometric parameters, we selected candidates with mu>0.28mas/yr and RF>16 in an area of 1150 square degrees. Then, we separated white dwarfs from late type dwarfs and subdwarfs by means of the reduced proper motion diagram. Finally, spectroscopic follow-up observations were carried out to confirm the white dwarf nature of the selected candidates. We found 41 white dwarfs of which 24 are new discoveries. Here we present the full sample and for each object provide positions, absolute proper motions, photometry, and spectroscopy.
- ID:
- ivo://CDS.VizieR/I/222
- Title:
- San Fernando AC Zone Data Reduced to ACRS
- Short Name:
- I/222
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The U.S. Naval Observatory is in the process of making new reductions of the Astrographic Catalogue (AC) using a modern reference system, the ACRS, which represents the system of the FK5. The data from the San Fernando Zone, whose plates are centered between declinations -3 and -9 degrees (eq. 1900), have been analyzed for scale, rotation, tilt, coma, magnitude equation, radial distortion and distortions introduced by the use of reseaux in the Carte du Ciel program. The result is a positional catalog of over 225,000 stars on eq. J2000.0, epoch of observation. Additionally, all stars have been matched with the Tycho Input Catalog (revised); those numbers have been added for additional identification purposes.
- ID:
- ivo://CDS.VizieR/J/AJ/129/1237
- Title:
- SARS galaxy luminosity profiles
- Short Name:
- J/AJ/129/1237
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have analyzed CCD images of 14 Abell clusters in the R filter of the Southern Abell Clusters Redshifts Survey (SARS) with cz<40,000km/s. We have obtained the luminosity profiles for 507 galaxies, of which 232 (46%) have known redshifts. In order to fit the luminosity profiles, we used the de Vaucouleurs law for bulge systems and an exponential profile for disk systems, and we also fitted the Sersic's law (r^n^) to all galaxy profiles.
- ID:
- ivo://CDS.VizieR/J/MNRAS/355/307
- Title:
- SA114 Ug'r'i'Z photometry
- Short Name:
- J/MNRAS/355/307
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This stellar catalogue contains 14439 stars classified by the stellarity index which is greater than 0.8 for all bands in Vega photometry. The catalogue is based on the Wide Field Camera CCD imaging of the field SA 114 with the 2.5m Isaac Newton Telescope in U(RGO), g', r', i', and Z(RGO), and covers 4.239 square-degrees at intermediate Galactic latitude (l=68.15{deg}, b=-48.38{deg}) epoch 2000. The limiting magnitudes within 5 sigma are 23.47, 24.97, 22.88, 22.20, and 22.09 for U(RGO), g', r', i', and Z(RGO), respectively. The catalogue gives the right ascension, declination, sub-field number and its CCD numbers, and magnitudes.
- ID:
- ivo://CDS.VizieR/J/ApJ/820/82
- Title:
- S2CLS: multiwavelength counterparts to SMGs
- Short Name:
- J/ApJ/820/82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multiwavelength identifications for the counterparts of 1088 submillimeter sources detected at 850{mu}m in the SCUBA-2 Cosmology Legacy Survey (S2CLS) study of the UKIRT Infrared Deep Sky Survey-Ultra-Deep Survey (UDS) field. By utilizing an Atacama Large Millimeter Array (ALMA) pilot study on a subset of our bright SCUBA-2 sample as a training set, along with the deep optical-near-infrared (OIR) data available in this field, we develop a novel technique, Optical-IR Triple Color (OIRTC), using z-K, K-[3.6], [3.6]-[4.5] colors to select the candidate submillimeter galaxy (SMG) counterparts. By combining radio identification and the OIRTC technique, we find counterpart candidates for 80% of the Class = 1 >=4{sigma} SCUBA-2 sample, defined as those that are covered by both radio and OIR imaging and the base sample for our scientific analyses. Based on the ALMA training set, we expect the accuracy of these identifications to be 82%+/-20%, with a completeness of 69%+/-16%, essentially as accurate as the traditional p-value technique but with higher completeness. We find that the fraction of SCUBA-2 sources having candidate counterparts is lower for fainter 850{mu}m sources, and we argue that for follow-up observations sensitive to SMGs with S_850_>~1mJy across the whole ALMA beam, the fraction with multiple counterparts is likely to be >40% for SCUBA-2 sources at S_850_>~4mJy. We find that the photometric redshift distribution for the SMGs is well fit by a lognormal distribution, with a median redshift of z=2.3+/-0.1. After accounting for the sources without any radio and/or OIRTC counterpart, we estimate the median redshift to be z=2.6+/-0.1 for SMGs with S_850_>1mJy. We also use this new large sample to study the clustering of SMGs and the far-infrared properties of the unidentified submillimeter sources by stacking their Herschel SPIRE far-infrared emission.
- ID:
- ivo://CDS.VizieR/J/MNRAS/454/902
- Title:
- SCORPIO 1 catalogue of compact radio sources
- Short Name:
- J/MNRAS/454/902
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radio emission has been detected in a broad variety of stellar objects from all stages of stellar evolution. However, most of our knowledge originates from targeted observations of small samples, which are strongly biased to sources which are peculiar at other wavelengths. In order to tackle this problem we have conducted a deep 1.4GHz survey by using the Australian Telescope Compact Array, with a net bandwidth of 1.7GHz (1.4-3.1GHz), following the same observing setup as that used for the Australia Telescope Large Area Survey project, this time choosing a region more appropriate for stellar work. In this paper, the Stellar Continuum Originating from Radio Physics In Ourgalaxy (SCORPIO) project is presented as well as results from the pilot experiment. The achieved rms is 30{mu}Jy and the angular resolution ~10arcsec. 614 point-like sources have been extracted just from the pilot field. Only 34 of them are classified in SIMBAD or the NASA/IPAC Extragalactic Database. About 80 percent of the extracted sources are reported in one of the inspected catalogues and 50 percent of them appears to belong to a reddened stellar/Galactic population. However, the evaluation of extragalactic contaminants is very difficult without further investigations. Interesting results have been obtained for extended radio sources that fall in the SCORPIO field. Many roundish-like structures (indicated as bubbles in the following) have been found, some of which are classified at other wavelengths. However, for all of these sources, our project has provided us with images of unprecedented sensitivity and angular resolution.
- ID:
- ivo://CDS.VizieR/J/ApJ/880/43
- Title:
- S2COSMOS: bright SCUBA-2 submm sources in COSMOS
- Short Name:
- J/ApJ/880/43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present sensitive 850{mu}m imaging of the Cosmological Evolution Survey (COSMOS) field using 640hr of new and archival observations taken with SCUBA-2 at the East Asian Observatory's James Clerk Maxwell Telescope. The SCUBA-2 COSMOS survey (S2COSMOS) achieves a median noise level of {sigma}_850{mu}m_=1.2mJy/beam over an area of 1.6deg^2^ (MAIN; Hubble Space Telescope/Advanced Camera for Surveys footprint), and {sigma}_850{mu}m_=1.7mJy/beam over an additional 1deg^2^ of supplementary (supp) coverage. We present a catalog of 1020 and 127 sources detected at a significance level of >4{sigma} and >4.3{sigma} in the main and supp regions, respectively, corresponding to a uniform 2% false-detection rate. We construct the single-dish 850{mu}m number counts at S_850_>2mJy and show that these S2COSMOS counts are in agreement with previous single-dish surveys, demonstrating that degree-scale fields are sufficient to overcome the effects of cosmic variance in the S_850_=2-10mJy population. To investigate the properties of the galaxies identified by S2COSMOS sources we measure the surface density of near-infrared-selected galaxies around their positions and identify an average excess of 2.0+/-0.2 galaxies within a 13" radius (~100kpc at z~2). The bulk of these galaxies represent near-infrared-selected submillimeter galaxies and/or spatially correlated sources and lie at a median photometric redshift of z=2.0+/-0.1. Finally, we perform a stacking analysis at submillimeter and far-infrared wavelengths of stellar-mass-selected galaxies (M_*_=10^10^-10^12^M_{sun}_) from z=0-4, obtaining high-significance detections at 850{mu}m in all subsets (signal-to-noise ratio, S/N=4-30), and investigate the relation between far-infrared luminosity, stellar mass, and the peak wavelength of the dust spectral energy distribution. The publication of this survey adds a new deep, uniform submillimeter layer to the wavelength coverage of this well-studied COSMOS field.
- ID:
- ivo://CDS.VizieR/J/MNRAS/468/250
- Title:
- SCUBA-2 Ambitious Sky Survey
- Short Name:
- J/MNRAS/468/250
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The SCUBA-2 Ambitious Sky Survey (SASSy) is composed of shallow 850-{mu}m imaging using the Submillimetre Common-User Bolometer Array 2 (SCUBA-2) on the James Clerk Maxwell Telescope. Here we describe the extraction of a catalogue of beam-sized sources from a roughly 120deg^2^ region of the Galactic plane mapped uniformly (to an rms level of about 40mJy), covering longitude 120{deg}<l<140{deg} and latitude |b|<2.9{deg}. We used a matched-filtering approach to increase the signal-to-noise ratio (S/N) in these noisy maps and tested the efficiency of our extraction procedure through estimates of the false discovery rate, as well as by adding artificial sources to the real images. The primary catalogue contains a total of 189 sources at 850{mu}m, down to an S/N threshold of approximately 4.6. Additionally, we list 136 sources detected down to S/N=4.3, but recognize that as we go lower in S/N, the reliability of the catalogue rapidly diminishes. We perform follow-up observations of some of our lower significance sources through small targeted SCUBA-2 images and list 265 sources detected in these maps down to S/N=5. This illustrates the real power of SASSy: inspecting the shallow maps for regions of 850-{mu}m emission and then using deeper targeted images to efficiently find fainter sources. We also perform a comparison of the SASSy sources with the Planck Catalogue of Compact Sources and the IRAS Point Source Catalogue, to determine which sources discovered in this field might be new, and hence potentially cold regions at an early stage of star formation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/436/430
- Title:
- SCUBA-2 cosmology legacy survey
- Short Name:
- J/MNRAS/436/430
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the multiwavelength properties of a sample of 450-{mu}m-selected sources from the SCUBA-2 Cosmology Legacy Survey. A total of 69 sources were identified above 4{sigma} in deep SCUBA-2 450-{mu}m observations overlapping the UDS and COSMOS fields and covering 210arcmin^2^ to a typical depth of {sigma}_450_=1.5mJy. Reliable cross-identifications are found for 58 sources (84 percent) in Spitzer and Hubble Space Telescope WFC3/IR data. The photometric redshift distribution (dN/dz) of 450-{mu}m-selected sources is presented, showing a broad peak in the redshift range 1<z<3 and a median of z=1.4. Combining the SCUBA-2 photometry with Herschel SPIRE data from HerMES, the submm spectral energy distribution (SED) is examined via the use of modified blackbody fits, yielding aggregate values for the IR luminosity, dust temperature and emissivity of <L_IR_>=10^12^+/-0.8L_{sun}_, <T_D_>=42+/-11K and <{beta}_D_>=1.6+/-0.5, respectively. The relationship between these SED parameters and the physical properties of galaxies is investigated, revealing correlations between T_D_ and L_IR_ and between {beta}D and both stellar mass and effective radius. The connection between the star formation rate (SFR) and stellar mass is explored, with 24 percent of 450-{mu}m sources found to be `starbursts', i.e. displaying anomalously high specific SFRs. However, both the number density and observed properties of these `starburst' galaxies are found to be consistent with the population of normal star-forming galaxies.
