- ID:
- ivo://CDS.VizieR/J/ApJ/775/45
- Title:
- PTI carbon star angular size survey
- Short Name:
- J/ApJ/775/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report new interferometric angular diameter observations of 41 carbon stars observed with the Palomar Testbed Interferometer. Two of these stars are CH carbon stars and represent the first such measurements of this subtype. Of these, 39 have Yamashita spectral classes and are of sufficiently high quality that we can determine the dependence of effective temperature on spectral type. We find that there is a tendency for the effective temperature to increase with increasing temperature index by ~120K per step, starting at T_eff_=~2500K for C3, y, although there is a large amount of scatter in this relationship. Overall, the median effective temperature of the carbon star sample is 2800+/-270 K and the median linear radius is 360+/-100R_{sun}_. We also find agreement, on average within 15K, with the T_eff_ determinations of Bergeat et al. (J/A+A/369/178) and a refinement of the carbon star angular size prediction based on V & K magnitudes is presented that is good to an rms of 12%. A subsample of our stars have sufficient {u, v} coverage to permit non-spherical modeling of their photospheres, and a general tendency for detection of statistically significant departures from sphericity with increasing interferometric signal-to-noise is seen. The implications of most -and potentially all- carbon stars being non-spherical is considered in the context of surface inhomogeneities and a rotation-mass-loss connection.
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- ID:
- ivo://CDS.VizieR/J/AJ/144/150
- Title:
- QCAL-1 43 GHz Calibrator Survey
- Short Name:
- J/AJ/144/150
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents the catalog of correlated flux densities in three ranges of baseline projection lengths of 637 sources from a 43GHz (Q band) survey observed with the Korean VLBI Network. Of them, 14 objects used as calibrators were previously observed, but 623 sources have not been observed before in the Q band with very long baseline interferometry (VLBI). The goal of this work in the early science phase of the new VLBI array is twofold: to evaluate the performance of the new instrument that operates in a frequency range of 22-129GHz and to build a list of objects that can be used as targets and as calibrators. We have observed the list of 799 target sources with declinations down to -40{deg}. Among them, 724 were observed before with VLBI at 22GHz and had correlated flux densities greater than 200mJy. The overall detection rate is 78%. The detection limit, defined as the minimum flux density for a source to be detected with 90% probability in a single observation, was in the range of 115-180mJy depending on declination. However, some sources as weak as 70mJy have been detected. Of 623 detected sources, 33 objects are detected for the first time in VLBI mode. We determined their coordinates with a median formal uncertainty of 20mas. The results of this work set the basis for future efforts to build the complete flux-limited sample of extragalactic sources at frequencies of 22GHz and higher at 3/4 of the celestial sphere.
- ID:
- ivo://CDS.VizieR/J/MNRAS/308/897
- Title:
- QDOT all-sky IRAS redshift survey
- Short Name:
- J/MNRAS/308/897
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalogue from the QDOT survey consists of infrared properties and redshifts of an all-sky sample of 2387 IRAS galaxies brighter than the IRAS PSC 60{mu}m completeness limit (S_60_>0.6Jy), sparsely sampled at a rate of one-in-six. At |b|>10{deg}, after removing a small number of Galactic sources, the redshift completeness is better than 98% (2086/2127). New redshifts for 1401 IRAS sources were obtained in 1985-88 at several telescopes (see "Note (8)" below) to complete the catalogue; the measurement and reduction of these are described, and the new redshifts tabulated here. We also tabulate all sources at |b|>10{deg} with no redshift so far, and sources with conflicting alternative redshifts either from our own work, or from published velocities. A list of 95 ultraluminous galaxies (i.e. with L(60{mu}m)>10^12^L_{sun}_) is also provided.
- ID:
- ivo://CDS.VizieR/J/PASP/124/1279
- Title:
- Q3 Kepler's combined photometry
- Short Name:
- J/PASP/124/1279
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Kepler Mission is searching for Earth-size planets orbiting solar-like stars by simultaneously observing >160000 stars to detect sequences of transit events in the photometric light curves. The Combined Differential Photometric Precision (CDPP) is the metric that defines the ease with which these weak terrestrial transit signatures can be detected. An understanding of CDPP is invaluable for evaluating the completeness of the Kepler survey and inferring the underlying planet population. This paper describes how the Kepler CDPP is calculated, and introduces tables of rms CDPP on a per-target basis for 3-, 6-, and 12-hr transit durations, which are now available for all Kepler observations. Quarter 3 is the first typical set of observations at the nominal length and completeness for a quarter, from 2009 September 18 to 2009 December 16, and we examine the properties of the rms CDPP distribution for this data set. Finally, we describe how to employ CDPP to calculate target completeness, an important use case.
- ID:
- ivo://CDS.VizieR/J/MNRAS/253/485
- Title:
- QMW IRAS galaxy catalogue
- Short Name:
- J/MNRAS/253/485
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This study presents a highly complete and reliable IRAS 60-micron galaxy catalog covering 82 percent of the sky. IRAS color conditions are used to exclude galactic sources, including the remaining cirrus sources. All sources flagged as extended, confused, or having a poor correlation coefficient with a point-source template are examined with the raw IRAS data and accurate fluxes determined using mapping routines. The completeness, reliability, and flux accuracy of the catalog are discussed. Identifications are made with existing optical galaxy catalogs and with galaxy redshift surveys in the literature. It is estimated that redshifts are available for 79 percent of the galaxies in the catalog with V less than 5000km/s, and the 3D distribution of such galaxies is displayed. The dipole component of the surface-brightness distribution of galaxies in the catalog is discussed.
- ID:
- ivo://CDS.VizieR/J/A+A/427/387
- Title:
- QORG catalog of radio/X-ray sources
- Short Name:
- J/A+A/427/387
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The QUASARS.ORG Catalogues align and overlay the year 2001/2 releases of the ROSAT HRI, RASS, PSPC and WGA X-ray catalogues, the NVSS (2002), FIRST (2003) and SUMSS (2003) radio catalogues, the Veron QSO catalogue (2003) and various galaxy/star reference catalogues onto the optical APM and USNO-A catalogues. These catalogues display calculated percentage probabilities for each optical radio/X-ray associated object of its likelihood of being a quasar, galaxy, star, or erroneous radio/X-ray association. The main Master catalogue (master.dat) displays all 501,761 radio/X-ray associated optical objects and known quasars which are optically detected in APM/USNO-A. Up to six radio/X-ray catalog identifications are presented for each optical object, plus any double radio lobes (21,498 of these). These are superimposed (and laterally fitted) onto a 670,925,779-object optical background which combines APM and USNO-A data. The Free-Lunch catalogue is a concise easy-to-read variant of the Master catalogue showcasing just one X-ray and/or radio identification for each object. This catalogue is the original version which was publicized to show astronomers that there *is* a free lunch after all! There is also a subset catalogue of QSO candidates, and a subset catalogue of known QSOs/galaxies/stars. Objects presented in this catalogue are those optical APM/USNO-A objects which are associated with X-ray/radio detections, or any optically-found catalogued QSO/AGN/Bl Lac objects, with confidence >40% of being a radio/X-ray emitting optical object. There are 501,761 objects included in all (including 48,285 catalogued quasars), representing the 99.4% coverage of the sky available from the APM and USNO-A. Each object is shown as one line bearing the position in equatorial coordinates, red and blue optical magnitudes (recalibrated) and PSF class, calculated probabilities of the object being, separately, a quasar, galaxy, star, or erroneous radio/X-ray association, any radio identification from each of the NVSS, FIRST and SUMSS surveys, including candidate double-lobe detections, any X-ray identification from each of the ROSAT HRI, RASS, PSPC and WGA surveys, including fluxes and field shifts of those identifications, plus, if already catalogued, the object name and redshift where applicable. The QORG catalogue and supporting data can be accessed from the catalogue home page at http://quasars.org/qorg-data.htm Questions or comments may be directed to eric@flesch.org
- ID:
- ivo://CDS.VizieR/J/A+A/618/A144
- Title:
- QSO candidates catalog with APOP & ALLWISE (QCC)
- Short Name:
- J/A+A/618/A144
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Quasars are spatially stationary, and they are essential objects in astrometry when defining reference frames. However, the census of quasars is far from complete. Mid-infared colors can be used to find quasar candidates because AGNs show a peculiar appearance in mid-infrared color, but these methods are incapable of separating quasars from AGNs.The aim of our study is to use astrometric and mid-infrared methods to select quasars and get a reliable quasar candidates catalog. We used a near-zero proper motion criterion in conjuction with WISE (all-sky Wide-field Infrared Survey Explorer) [W1-W2] color to select quasar candidates. The [W1-W2] color criterion is defined by the linear boundary of two samples: LAMOST DR5 quasars, which serve as the quasar sample, and LAMOST DR5 stars/galaxies, which serve as the non-quasar sample. The contamination and completeness are evaluated. We present a catalog of 662753 quasar candidates, with a completeness of about 75% and a reliability of 77.2%.
- ID:
- ivo://CDS.VizieR/J/ApJ/747/107
- Title:
- QSO Candidates in the MACHO LMC database
- Short Name:
- J/ApJ/747/107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog the 2566 QSO candidates in the MACHO LMC database. In these catalogs, we complied number of properties of the objects including RA, Dec, crossmatched IDs with several catalogs, magnitudes, photometric redshifts, etc. See Kim et al. (2011ApJ...735...68K) for the SVM (a.k.a. Support Vector Machine, a supervised machine learning algorithm) QSO classification model based on the time variability of lightcurves. We used the model to select the 2566 QSO candidates. In this work, we employed multiple diagnostics such as X-ray flux, mid-IR color and AGN SED fitting in order to select 663 promising QSO candidates among the 2,566 candidates. These candidates are flagged in the catalog. We calibrated the MACHO RA and Dec of the candidates using the UCAC3 catalog and improved the average astrometric accuracy from ~3" to ~0.5".
- ID:
- ivo://CDS.VizieR/J/MNRAS/396/223
- Title:
- QSO candidates selection in VO era
- Short Name:
- J/MNRAS/396/223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a method for the photometric selection of candidate quasars in multiband surveys. The method makes use of a priori knowledge derived from a subsample of spectroscopic confirmed quasi-stellar objects (QSOs) to map the parameter space. The disentanglement of QSOs candidates and stars is performed in the colour space through the combined use of two algorithms, the probabilistic principal surfaces and the negative entropy clustering, which are for the first time used in an astronomical context. Both methods have been implemented in the voneural package on the Astrogrid Virtual Observatory platform. Even though they belong to the class of the unsupervised clustering tools, the performances of the method are optimized by using the available sample of confirmed quasars and it is therefore possible to learn from any improvement in the available 'base of knowledge'. The method has been applied and tested on both optical and optical plus near-infrared data extracted from the visible Sloan Digital Sky Survey (SDSS) and infrared United Kingdom Infrared Deep Sky Survey-Large Area Survey public data bases. In all cases, the experiments lead to high values of both efficiency and completeness, comparable if not better than the methods already known in the literature. A catalogue of optical candidate QSOs extracted from the SDSS Data Release 7 Legacy photometric data set has been produced.
- ID:
- ivo://CDS.VizieR/J/ApJ/710/1498
- Title:
- QSO luminosity function at z~4
- Short Name:
- J/ApJ/710/1498
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The evolution of the quasar luminosity function (QLF) is one of the basic cosmological measures providing insight into structure formation and mass assembly in the universe. We have conducted a spectroscopic survey to find faint quasars (-26.0<M_1450_<-22.0) at redshifts z=3.8-5.2 in order to measure the faint end of the QLF at these early times. Using available optical imaging data from portions of the NOAO Deep Wide-Field Survey and the Deep Lens Survey, we have color-selected quasar candidates in a total area of 3.76deg^2^. Thirty candidates have R<=23mag. We conducted spectroscopic follow-up for 28 of our candidates and found 23 QSOs, 21 of which are reported here for the first time, in the 3.74<z<5.06 redshift range.
