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1031. Catalog of variability selected AGNs in GOODS
ID:
ivo://CDS.VizieR/J/ApJ/723/737
Title:
Catalog of variability selected AGNs in GOODS
Short Name:
J/ApJ/723/737
Date:
21 Oct 2021
Publisher:
CDS
Description:
Variability is a property shared by practically all active galactic nuclei (AGNs). This makes variability selection a possible technique for identifying AGNs. Given that variability selection makes no prior assumption about spectral properties, it is a powerful technique for detecting both low-luminosity AGNs in which the host galaxy emission is dominating and AGNs with unusual spectral properties. In this paper, we will discuss and test different statistical methods for the detection of variability in sparsely sampled data that allow full control over the false positive rates. We will apply these methods to the GOODS North and South fields and present a catalog of variable sources in the z band in both GOODS fields. Out of the 11 931 objects checked, we find 155 variable sources at a significance level of 99.9%, corresponding to about 1.3% of all objects. After rejection of stars and supernovae, 139 variability-selected AGNs remain. Their magnitudes reach down as faint as 25.5mag in z. Spectroscopic redshifts are available for 22 of the variability-selected AGNs, ranging from 0.046 to 3.7. The absolute magnitudes in the rest-frame z band range from ~-18 to -24, reaching substantially fainter than the typical luminosities probed by traditional X-ray and spectroscopic AGN selection in these fields. Therefore, this is a powerful technique for future exploration of the evolution of the faint end of the AGN luminosity function up to high redshifts.
1032. Catalog of white dwarfs in SDSS-DR1
ID:
ivo://CDS.VizieR/J/ApJ/607/426
Title:
Catalog of white dwarfs in SDSS-DR1
Short Name:
J/ApJ/607/426
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the full spectroscopic white dwarf and hot subdwarf sample from the Sloan Digital Sky Survey (SDSS) First Data Release, DR1. We find 2551 white dwarf stars of various types, 240 hot subdwarf stars, and an additional 144 objects we have identified as uncertain white dwarf stars. Of the white dwarf stars, 1888 are nonmagnetic DA types and 171 are nonmagnetic DBs. The remaining (492) objects consist of all different types of white dwarf stars: DO, DQ, DC, DH, DZ, hybrid stars such as DAB, etc., and those with nondegenerate companions. We fit the DA and DB spectra with a grid of models to determine the T_eff_ and logg for each object. For all objects, we provide coordinates, proper motions, SDSS photometric magnitudes, and enough information to retrieve the spectrum/image from the SDSS public database. This catalog nearly doubles the known sample of spectroscopically identified white dwarf stars. In the DR1 imaged area of the sky, we increase the known sample of white dwarf stars by a factor of 8.5. We also comment on several particularly interesting objects in this sample.
1033. Catalog of X-ray selected BL Lac objects
ID:
ivo://CDS.VizieR/J/AJ/145/31
Title:
Catalog of X-ray selected BL Lac objects
Short Name:
J/AJ/145/31
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper presents a catalog of 312 X-ray selected BL Lacertae objects (XBLs), optically identified through the end of 2011. It contains the names from different surveys, equatorial coordinates, redshifts, multifrequency flux values, and luminosities for each source. In addition, the different characteristics of XBLs are statistically investigated (redshift, radio/optical/X-ray luminosities, central black hole (BH) mass, synchrotron peak frequency, broadband spectral indices, optical flux variability). Their values are collected through an extensive bibliographic and database search or calculated by us. The redshifts range from 0.031 to 0.702 with a maximum of the distribution at z=0.223. The 1.4GHz luminosities of XBLs log{nu}L_{nu}_~39-42erg/s while optical V and X-ray 0.1-2.4keV bands show log{nu}L_{nu}_~43-46erg/s. The XBL hosts are elliptical galaxies with effective radii r_eff_=3.26-25.40kpc and ellipticities, {epsilon}=0.04-0.52. Their R-band absolute magnitudes M_R_ range from -21.11mag to -24.86mag with a mean value of -22.83mag. The V-R indices of the hosts span from 0.61 to 1.52 and reveal a fourth-degree polynomial relationship with z that enables us to evaluate the redshifts of five sources whose V-R indices were determined from the observations but whose redshifts values are either not found or not confirmed. The XBL nuclei show a wider range of 7.31mag for M_R_ with the highest luminosity corresponding to M_R_=-27.24mag. The masses of central BHs are found in the interval logM_BH_=7.39-9.30 solar masses (with distribution maximum at logM_BH_/M_{sun}_=8.30). The synchrotron peak frequencies are spread over the range log{nu}_peak_=14.56-19.18Hz with a peak of the distribution at log{nu}_peak_=16.60Hz. The broadband radio-to-optical ({alpha}_ro_), optical-to-X-ray ({alpha}_ox_), and radio-to-X-ray ({alpha}_rx_) spectral indices are distributed in the intervals (0.17,0.59), (0.56,1.48), and (0.41,0.75), respectively. In the optical energy range, the overall flux variability increases, on average, towards shorter wavelengths: <{Delta}m>=1.22,1.50, and 1.82mag through the R, V, B bands of Johnson-Cousins system, respectively. XBLs seem be optically less variable at the intranight timescales compared to the radio-selected BL Lacs (RBLs).
1034. Catalog of X-ray sources in NGC 4278
ID:
ivo://CDS.VizieR/J/ApJS/181/605
Title:
Catalog of X-ray sources in NGC 4278
Short Name:
J/ApJS/181/605
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the properties of the discrete X-ray sources detected in our monitoring program of the globular cluster (GC) rich elliptical galaxy, NGC 4278, observed with Chandra ACIS-S in six separate pointings, resulting in a co-added exposure of 458ks. From this deep observation, 236 sources have been detected within the region overlapped by all observations, 180 of which lie within the D25 ellipse of the galaxy. These 236 sources range in L_X_ from 3.5x10^36^erg/s (with 3{sigma} upper limit <=1x10^37^erg/s) to ~2x10^40^erg/s, including the central nuclear source which has been classified as a LINER. From optical data, 39 X-ray sources have been determined to be coincident with a GC, these sources tend to have high X-ray luminosity, with 10 of these sources exhibiting L_X_>1x10^38^erg/s. From X-ray source photometry, it has been determined that the majority of the 236 point sources that have well-constrained colors have values that are consistent with typical low-mass X-ray binary spectra, with 29 of these sources expected to be background objects from the log N-log S relation. There are 103 sources in this population that exhibit long-term variability, indicating that they are accreting compact objects. Three of these sources have been identified as transient candidates, with a further three possible transients. Spectral variations have also been identified in the majority of the source population, where a diverse range of variability has been identified, indicating that there are many different source classes located within this galaxy.
1035. Catalog of X-ray sources in the CYDER fields
ID:
ivo://CDS.VizieR/J/ApJ/621/104
Title:
Catalog of X-ray sources in the CYDER fields
Short Name:
J/ApJ/621/104
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first results from the Calan-Yale Deep Extragalactic Research (CYDER) survey. The main goal of this survey is to study serendipitous X-ray sources detected by Chandra in an intermediate flux range (10^-15^ to 10^-12^ergs/s) that comprises most of the X-ray background. A total of 267 X-ray sources spread over five archived fields were detected.
1036. Catalog of X-ray sources in the NARCS
ID:
ivo://CDS.VizieR/J/ApJ/796/105
Title:
Catalog of X-ray sources in the NARCS
Short Name:
J/ApJ/796/105
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of 1415 X-ray sources identified in the Norma Arm Region Chandra Survey (NARCS), which covers a 2{deg}x0.8{deg} region in the direction of the Norma spiral arm to a depth of ~20 ks. Of these sources, 1130 are point-like sources detected with >=3{sigma} confidence in at least one of three energy bands (0.5-10, 0.5-2, and 2-10 keV), five have extended emission, and the remainder are detected at low significance. Since most sources have too few counts to permit individual classification, they are divided into five spectral groups defined by their quantile properties. We analyze stacked spectra of X-ray sources within each group, in conjunction with their fluxes, variability, and infrared counterparts, to identify the dominant populations in our survey. We find that ~50% of our sources are foreground sources located within 1-2 kpc, which is consistent with expectations from previous surveys. Approximately 20% of sources are likely located in the proximity of the Scutum-Crux and near Norma arm, while 30% are more distant, in the proximity of the far Norma arm or beyond. We argue that a mixture of magnetic and nonmagnetic cataclysmic variables dominates the Scutum-Crux and near Norma arms, while intermediate polars and high-mass stars (isolated or in binaries) dominate the far Norma arm. We also present the cumulative number count distribution for sources in our survey that are detected in the hard energy band. A population of very hard sources in the vicinity of the far Norma arm and active galactic nuclei dominate the hard X-ray emission down to f_X_~10^-14^ erg/cm^2^/s, but the distribution curve flattens at fainter fluxes. We find good agreement between the observed distribution and predictions based on other surveys.
1037. Catalogue and Bibliography of UV Cet stars
ID:
ivo://CDS.VizieR/J/A+AS/139/555
Title:
Catalogue and Bibliography of UV Cet stars
Short Name:
J/A+AS/139/555
Date:
21 Oct 2021
Publisher:
CDS
Description:
This new catalogue of flare stars includes 463 objects. It contains astrometric, spectral and photometric data as well as information on the infrared, radio and X-ray properties and general stellar parameters. From the total reference list of about 3400 articles, partial lists selected by objects, authors, key words and by any pairs of these criteria can be obtained.
1038. Catalogue of Blue Stragglers
ID:
ivo://CDS.VizieR/J/A+A/483/183
Title:
Catalogue of Blue Stragglers
Short Name:
J/A+A/483/183
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the Blue Stragglers (BSS) Catalogues extracted from the photometric data base of 74 Galactic GCs published by Piotto et al., 2002, Cat. <J/A+A/391/945>. All the clusters were observed in the F439W and F555W photometric bands pointing the HST/WFPC2 camera to the central core. Candidates were selected according to their position in the colour magnitude diagrams. A detailed description of the selection process is given in the paper. We give for each cluster a list of blue straggler candidates together with their photometric data.
1039. Catalogue of bright (K<9) M dwarfs
ID:
ivo://CDS.VizieR/J/MNRAS/435/2161
Title:
Catalogue of bright (K<9) M dwarfs
Short Name:
J/MNRAS/435/2161
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using the Position and Proper Motion Extended-L (PPMXL) catalogue, we have used optical and near-infrared colour cuts together with a reduced proper motion cut to find bright M dwarfs for future exoplanet transit studies. PPMXL's low proper motion uncertainties allow us to probe down to smaller proper motions than previous similar studies. We have combined unique objects found with this method to that of previous work to produce 8479 K<9 M dwarfs. Low-resolution spectroscopy was obtained of a sample of the objects found using this selection method to gain statistics on their spectral type and physical properties. Results show a spectral-type range of K7-M4V. This catalogue is the most complete collection of K<9 M dwarfs currently available and is made available here.
1040. Catalogue of bright YSO candidates in ISOGAL
ID:
ivo://CDS.VizieR/J/A+A/392/971
Title:
Catalogue of bright YSO candidates in ISOGAL
Short Name:
J/A+A/392/971
Date:
21 Oct 2021
Publisher:
CDS
Description:
The 7 and 15{mu}m observations of selected fields in the Galactic Plane obtained with ISOCAM during the ISOGAL program offer an unique possibility to search for previously unknown YSOs, undetected by IRAS because of lower sensitivity or confusion problems. In a previous paper (Felli et al., 2000, Cat. <J/A+A/362/199>) we established criteria of general validity to select YSOs from the much larger population of Post Main Sequence (Post-MS) stars present in the ISOGAL fields by comparing radio and IR observations of five fields located at l~45{deg}. The selection was based primarily on the position of the point sources in the [15]-([7]-[15]) diagram, which involves only ISOGAL data and allows to find possible YSOs using the survey data alone. In the present work we revise the adopted criteria by comparing radio-identified ultra-compact HII regions and ISOGAL observations over a much larger region. The main indications of the previous analysis are confirmed, but the criteria for selecting YSO candidates had to be revised to select only bright objects, in order to limit the contamination of the sample by Post-MS stars. The revised criteria ([15]<=4.5, [7]-[15]>=1.8) are then used to extract YSO candidates from the ISOGAL Point Source Catalogue in preparation. We select a total of 715 YSO candidates, corresponding to ~2 of the sources with good detections at 7 and 15{mu}m. The results are presented in a table form that provides an unique input list of small diameter, <=6", Galactic YSO candidates. The global properties of the sample of YSO candidates are briefly discussed.