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641. The Washington Visual Double Star Catalog, 1996.0
ID:
ivo://CDS.VizieR/I/237
Title:
The Washington Visual Double Star Catalog, 1996.0
Short Name:
I/237
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Washington Visual Double Star Catalog, 1996.0 (WDS) is the successor to the catalog of the same name dated 1984 <I/107>. The WDS is intended to contain all known visual double stars for which at least one differential measure has been published through the end of 1995. It includes a discoverer code, the date of the first and last observations, the number of observations, the position angle and separation for the first and last observation, the magnitudes and spectral types of the components (when available) the proper motion of the system, Durchmusterung numbers of the components and notes for further information.
642. The Wide-field VLBA Calibrator Survey (WFCS)
ID:
ivo://CDS.VizieR/J/AJ/161/14
Title:
The Wide-field VLBA Calibrator Survey (WFCS)
Short Name:
J/AJ/161/14
Date:
09 Mar 2022
Publisher:
CDS
Description:
This paper presents the results of the largest very long baseline interferometry (VLBI) absolute astrometry campaign to date of 13645 radio source observations with the Very Long Baseline Array. Of these, 7220 have been detected, including 6755 target sources that have never been observed with VLBI before. This makes the present VLBI catalog the largest ever published. The positions of the target sources have been determined with the median uncertainty of 1.7mas, and 15542 images of 7171 sources have been generated. Unlike previous absolute radio astrometry campaigns, observations were made at 4.3 and 7.6GHz simultaneously using a single wide-band receiver. Because of the fine spectral and time resolutions, the field of view was 4'-8'-much greater than the 10"-20" in previous surveys. This made possible the use of input catalogs with low position accuracy and the detection of a compact component in extended sources. Unlike previous absolute astrometry campaigns, both steep- and flat-spectrum sources were observed. The observations were scheduled in the so-called filler mode to fill the gaps between other high-priority programs. This was achieved by the development of the totally automatic scheduling procedure.
643. The XXL Survey. XLI. GMRT XXL-N 610MHz
ID:
ivo://CDS.VizieR/J/A+A/638/A46
Title:
The XXL Survey. XLI. GMRT XXL-N 610MHz
Short Name:
J/A+A/638/A46
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the space density evolution of active galactic nuclei (AGN) using the 610MHz radio survey of the XXL-North field, performed with the Giant Metrewave Radio Telescope (GMRT). The survey covers an area of 30.4deg^2^, with a beamsize of 6.5arcsec. The survey is divided into two parts, one covering an area of 11.9deg^2^ with 1{sigma} rms noise of 200uJy/beam and the other spanning 18.5deg^2^ with rms noise of 45uJy/beam. We extracted the catalog of radio components above 7. The catalog was cross-matched with a multi-wavelength catalog of the XXL-North field (covering about 80% of the radio XXL-North field) using a likelihood ratio method, which determines the counterparts based on their positions and their optical properties. The multi-component sources were matched visually with the aid of a computer code: Multi-Catalog Visual Cross-Matching (MCVCM). A flux density cut above 1mJy selects AGN hosts with a high purity in terms of star formation contamination based on the available source counts. After crossmatching and elimination of observational biases arising from survey incompleteness, the number of remaining sources was 1150. We constructed the rest-frame 1.4GHz radio luminosity functions of these sources using the maximum volume method. This survey allows us to probe luminosities of 23<~log(L1.4GHz[W/Hz])<~28 up to redshifts of z~=2.1. Our results are consistent with the results from the literature in which AGN are comprised of two differently evolving populations, where the high luminosity end of the luminosity functions evolves more strongly than the low-luminosity end.
644. Third VLBA calibrator survey: VCS3
ID:
ivo://CDS.VizieR/J/AJ/129/1163
Title:
Third VLBA calibrator survey: VCS3
Short Name:
J/AJ/129/1163
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the third extension to the Very Long Baseline Array (VLBA) Calibrator Survey, containing 360 new sources not previously observed with Very Long Baseline Interferometry (VLBI). The survey, based on three 24 hour VLBA observing sessions, fills the areas on the sky above declination -45{deg} where the calibrator density is less than one source within a 4{deg} radius disk at any given direction. The positions were derived from astrometric analysis of the group delays determined at 2.3 and 8.6GHz frequency bands using the CALC/SOLVE software package. The VCS3 catalog of source positions, plots of correlated flux density versus length of projected baseline, and contour plots and FITS files of naturally weighted CLEAN images, as well as calibrated visibility function files, are available electronically from the Goddard Geodetic VLBI Group.
645. Time stability of the ICRF2 axes
ID:
ivo://CDS.VizieR/J/A+A/553/A122
Title:
Time stability of the ICRF2 axes
Short Name:
J/A+A/553/A122
Date:
21 Oct 2021
Publisher:
CDS
Description:
I assess the astrometric stability of the 295 defining sources of the current best realization of the International Celestial Reference System (ICRS): the second realization of the International Celestial Reference Frame (ICRF2), constructed and published in 2009 after the analysis of millions of VLBI observations at 2 and 8 GHz between 1979.6 and 2009.2. I also assess the time evolution of the ICRF2 axis stability. I derived coordinate time series of hundreds of quasars monitored by the regular geodetic VLBI program of the International VLBI Service for Geodesy and Astrometry (IVS). The axis stability was studied by constructing annual reference frames based on the ICRF2 defining sources. The time variable frame stability was obtained by computing the deformation parameters that lead from one frame to the next. I show that, although the astrometric stability of some of the ICRF2 defining sources has slightly degraded since 2009.2, the ensemble still constitutes a very stable reference frame. The current estimation of the axis stability over 1979.6-2013.1 remains at the same level as the one estimated over 1979.6-2009.2, i.e., on the order of 20uas for each axis.
646. TMGS star positions
ID:
ivo://CDS.VizieR/J/ApJ/491/L31
Title:
TMGS star positions
Short Name:
J/ApJ/491/L31
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an analysis of the optical spectroscopy of 58 stars in the Galactic plane at l=27deg, where a prominent excess in the flux distribution and star counts have been observed in several spectral regions, in particular in the Two-Micron Galactic Survey (TMGS) catalog. The sources were selected from the TMGS to have a K magnitude brighter than +5mag and to be within 2deg of the Galactic plane. More than 60% of the spectra correspond to stars of luminosity class I, and a significant proportion of the remainder are very late and fast-evolving giants. This very high concentration of young sources points to the existence of a major star formation region in the Galactic plane, located just inside the assumed origin of the Scutum spiral arm. Such regions can form because of the concentrations of shocked gas where a galactic bar meets a spiral arm, as is observed at the ends of the bars of face-on external galaxies. Thus, the presence of a massive star formation region is very strong supporting evidence for the presence of a bar in our Galaxy.
647. 2007.5 to 2010.4 HST astrometry of HD 202206
ID:
ivo://CDS.VizieR/J/AJ/153/258
Title:
2007.5 to 2010.4 HST astrometry of HD 202206
Short Name:
J/AJ/153/258
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using Hubble Space Telescope Fine Guidance Sensor astrometry and previously published radial velocity measures, we explore the exoplanetary system HD202206. Our modeling results in a parallax, {pi}_abs_=21.96+/-0.12 milliseconds of arc, a mass for HD202206B of M_B_=0.089_-0.006_^+0.007M_{Sun}_, and a mass for HD202206c of M_c_=17.9_-1.8_^+2.9^M_Jup_. HD202206 is a nearly face-on G + M binary orbited by a brown dwarf. The system architecture that we determine supports past assertions that stability requires a 5:1 mean motion resonance (we find a period ratio, P_c_/P_B_=4.92+/-0.04) and coplanarity (we find a mutual inclination, {Phi}=6{deg}+/-2{deg}).
648. Tokyo Photoelectric Meridian Circle Catalog 1989
ID:
ivo://CDS.VizieR/I/198
Title:
Tokyo Photoelectric Meridian Circle Catalog 1989
Short Name:
I/198
Date:
21 Oct 2021
Publisher:
CDS
Description:
The fifth annual catalog of the Tokyo PMC is presented for 3466 stars (Part I and Part II) which were observed at least two times in the 1989 period, that is, from January 1, 1989, to December 31, 1989. The positions of the stars given in the catalog are those at the mean epoch of observations. The coordinates of the catalog are based on the FK5 system, and refer to the equinox and equator of J2000.0. The values of (O-C)s in the catalog are calculated by using the positions given in the source catalog, and by evaluating those at the mean epoch of observations of each star, with the equinox and equator at the mean epoch. The magnitudes of the stars given in the catalog can be transformed into the V-magnitude of the standard UBV system by the equation: V = V(TPMC) + 0.063 ( B-V ) - 0.045. The mean trends of the observed positions-FK5 positions for the basic FK5 stars are constructed and compared with those of the Tokyo PMC Catalogs 86, 87, and 88. The Part I of the catalog contains the positions of 1080 basic FK5 stars, 210 FK4 Suppl. stars, 1700 AGK3R stars, 131 OB stars, 36 NPZT stars, and 96 SAO stars, observed with the Tokyo PMC in the 1989 period based on FK5 system. The Part II of the catalog contains the positions of 210 zodiacal stars observed with the Tokyo PMC in the 1989 period based on the FK5 system. The stars of the Part II are usable for the reduction of lunar occultation. The Parts I and II are concatenated to form a single machine-readable catalog.
649. Tokyo Photoelectric Meridian Circle Catalog 1987
ID:
ivo://CDS.VizieR/I/187
Title:
Tokyo Photoelectric Meridian Circle Catalog 1987
Short Name:
I/187
Date:
21 Oct 2021
Publisher:
CDS
Description:
The third annual catalog of the Tokyo PMC is presented for 5748 stars which had been observed at least two times in the year 1987 period, that is, from January 1, 1987, to December 31, 1987. The positions of the stars given in the catalog are those at the mean epoch of observations. The coordinates of the catalog are referred to the equinox and equator of J2000.0, based on the FK5 system. The mean trends of the observed positions minus FK5 positions for the FK5 basics stars are constructed and compared with those of the Tokyo PMC 86 catalog. The part I of the catalog contains the positions of 1017 FK5 basics (=FK4 stars ), 533 FK4 Suppl. stars, 2421 AGK3R stars, 1167 OB stars, 113 NPZT stars, and 84 SAO stars, and the part II of the catalog contains the positions of 413 SAO stars for occultation studies. These two parts were merged into a single pmc87 file.
650. Tokyo Photoelectric Meridian Circle Catalog 1985
ID:
ivo://CDS.VizieR/I/186
Title:
Tokyo Photoelectric Meridian Circle Catalog 1985
Short Name:
I/186
Date:
21 Oct 2021
Publisher:
CDS
Description:
The catalog of positions of 1007 stars (792 FK4 and FK4S stars, 57 OB stars, 49 NPZT stars, and 109 SAO stars) is presented. They were observed during the period from December 1984 to September 1985 with the Tokyo Photoelectric Meridian Circle (Tokyo PMC). The positions in the catalog are referred to the equinox and equator of J2000, and are based on the FK4 system. The internal errors of a single observation were estimated to be (epsilon(alpha)*cos(delta), epsilon(delta)) = (0.16", 0.19"), whereas the mean internal errors of the catalog positions were (0.08", 0.08") for FK4 stars and (0.09", 0.11") for FK4S stars. The comparison of the positions of the FK4 stars in the present catalog with those of the FK4 catalog shows the significant differences delta(alpha(delta)) and delta(delta(delta)) in some declination zones. Some of those differences are commonly found in other recent catalogs. Thus they may be considered to be the real systematic errors in the FK4 system. Neither significant magnitude nor color equation exists in the Tokyo PMC85 catalog.

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