- ID:
- ivo://CDS.VizieR/J/ApJ/709/377
- Title:
- The globular cluster system of NGC 4636
- Short Name:
- J/ApJ/709/377
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic study of the globular clusters (GCs) in the giant elliptical galaxy NGC 4636 in the Virgo Cluster. We selected target GC candidates using the Washington photometry derived from the deep CCD images taken at the KPNO 4m Telescope. Then we obtained the spectra of 164 target objects in the field of NGC 4636 using the Multi-Object Spectroscopy mode of Faint Object Camera and Spectrograph on the Subaru 8.2m Telescope. We have measured the velocities for 122 objects: 105 GCs in NGC 4636, the nucleus of NGC 4636, 11 foreground stars, two background galaxies, and three probable intracluster GCs in the Virgo Cluster. The GCs in NGC 4636 are located in the projected galactocentric radius within 10' (corresponding to 43kpc). The measured velocities for the GCs range from ~300km/s to ~1600km/s, with a mean value of 932^+25^_-22_km/s, which is in good agreement with the velocity for the nucleus of NGC 4636, 928+/-45km/s.
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- ID:
- ivo://CDS.VizieR/J/ApJ/797/31
- Title:
- The G+M eclipsing binary V530 Orionis photometry
- Short Name:
- J/ApJ/797/31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report extensive photometric and spectroscopic observations of the 6.1 day period, G+M-type detached double-lined eclipsing binary V530 Ori, an important new benchmark system for testing stellar evolution models for low-mass stars. We determine accurate masses and radii for the components with errors of 0.7% and 1.3%, as follows: M_A_=1.0038+/-0.0066 M_{sun}_, M_B_=0.5955+/-0.0022 M_{sun}_, R_A_=0.980+/-0.013 R_{sun}_, and R_B_=0.5873+/-0.0067 R_{sun}_. The effective temperatures are 5890+/-100 K (G1 V) and 3880+/-120 K (M1 V), respectively. A detailed chemical analysis probing more than 20 elements in the primary spectrum shows the system to have a slightly subsolar abundance, with [Fe/H]=-0.12+/-0.08. A comparison with theory reveals that standard models underpredict the radius and overpredict the temperature of the secondary, as has been found previously for other M dwarfs. On the other hand, models from the Dartmouth series incorporating magnetic fields are able to match the observations of the secondary star at the same age as the primary (~3 Gyr) with a surface field strength of 2.1+/-0.4 kG when using a rotational dynamo prescription, or 1.3+/-0.4 kG with a turbulent dynamo approach, not far from our empirical estimate for this star of 0.83+/-0.65 kG. The observations are most consistent with magnetic fields playing only a small role in changing the global properties of the primary. The V530 Ori system thus provides an important demonstration that recent advances in modeling appear to be on the right track to explain the long-standing problem of radius inflation and temperature suppression in low-mass stars.
- ID:
- ivo://CDS.VizieR/J/A+A/598/A78
- Title:
- The GMRT 150MHz all-sky radio survey
- Short Name:
- J/A+A/598/A78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first full release of a survey of the 150MHz radio sky, observed with the Giant Metrewave Radio Telescope (GMRT) between April 2010 and March 2012 as part of the TIFR GMRT Sky Survey (TGSS) project. Aimed at producing a reliable compact source survey, our automated data reduction pipeline efficiently processed more than 2000h of observations with minimal human interaction. Through application of innovative techniques such as image-based flagging, direction-dependent calibration of ionospheric phase errors, correcting for systematic offsets in antenna pointing, and improving the primary beam model, we created good quality images for over 95 percent of the 5336 pointings. Our data release covers 36900deg^2^ (or 3.6{pi}steradians) of the sky between -53{deg} and +90{deg} declination (Dec), which is 90 percent of the total sky. The majority of pointing images have a noise level below 5mJy/beam with an approximate resolution of 25"x25" (or 25"x25"/cos(Dec-19{deg}) for pointings south of 19{deg} declination). We have produced a catalog of 0.62 Million radio sources derived from an initial, high reliability source extraction at the seven sigma level. For the bulk of the survey, the measured overall astrometric accuracy is better than two arcseconds in right ascension and declination, while the flux density accuracy is estimated at approximately ten percent. Within the scope of the TGSS alternative data release (TGSS ADR) project, the source catalog, as well as 5336 mosaic images (5{deg}x5{deg}) and an image cutout service, are made publicly available at the CDS as a service to the astronomical community. Next to enabling a wide range of different scientific investigations, we anticipate that these survey products will provide a solid reference for various new low-frequency radio aperture array telescopes (LOFAR, LWA, MWA, SKA-low), and can play an important role in characterizing the epoch-of-reionisation (EoR) foreground. The TGSS ADR project aims at continuously improving the quality of the survey data products. Near-future improvements include replacement of bright source snapshot images with archival targeted observations, using new observations to fill the holes in sky coverage and replace very poor quality observational data, and an improved flux calibration strategy for less severely affected observational data.
- ID:
- ivo://CDS.VizieR/J/A+A/588/A146
- Title:
- The gNLS1 galaxy PKS 2004-447. VLBI images
- Short Name:
- J/A+A/588/A146
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Gamma-ray-detected radio-loud narrow-line Seyfert 1 (g-NLS1) galaxies constitute a small but interesting sample of the g-ray-loud AGN. The radio-loudest g-NLS1 known, PKS 2004-447, is located in the southern hemisphere and is monitored in the radio regime by the multiwavelength monitoring programme TANAMI. We aim for the first detailed study of the radio morphology and long-term radio spectral evolution of PKS 2004-447, which are essential for understanding the diversity of the radio properties of g-NLS1s. The TANAMI VLBI monitoring program uses the Australian Long Baseline Array (LBA) and telescopes in Antarctica, Chile, New Zealand, and South Africa to monitor the jets of radio-loud active galaxies in the southern hemisphere. Lower resolution radio flux density measurements at multiple radio frequencies over four years of observations were obtained with the Australia Telescope Compact Array (ATCA). The TANAMI VLBI image at 8.4GHz shows an extended one-sided jet with a dominant compact VLBI core. Its brightness temperature is consistent with equipartition, but it is an order of magnitude below other g-NLS1s with the sample value varying over two orders of magnitude. We find a compact morphology with a projected large-scale size <11kpc and a persistent steep radio spectrum with moderate flux-density variability. PKS 2004-447 appears to be a unique member of the g-NLS1 sample. It exhibits blazar-like features, such as a flat featureless X-ray spectrum and a core-dominated, one-sided parsec-scale jet with indications for relativistic beaming. However, the data also reveal properties atypical for blazars, such as a radio spectrum and large-scale size consistent with compact-steep-spectrum (CSS) objects, which are usually associated with young radio sources. These characteristics are unique among all g-NLS1s and extremely rare among g-ray-loud AGN.
- ID:
- ivo://CDS.VizieR/J/ApJS/252/15
- Title:
- The GNRIS-Distant Quasar Survey (GNRIS-DQS)
- Short Name:
- J/ApJS/252/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectroscopic measurements for 226 sources from the Gemini Near Infrared Spectrograph-Distant Quasar Survey (GNIRS-DQS). Being the largest uniform, homogeneous survey of its kind, it represents a flux-limited sample (m_i_<~19.0mag, H<~16.5mag) of Sloan Digital Sky Survey (SDSS) quasars at 1.5<~z<~3.5 with a monochromatic luminosity ({lambda}L_{lambda}_) at 5100{AA} in the range of 10^44^-10^46^erg/s. A combination of the GNIRS and SDSS spectra covers principal quasar diagnostic features, chiefly the CIV{lambda}1549, MgII{lambda}{lambda}2798,2803, H{beta}{lambda}4861, and [OIII]{lambda}{lambda}4959,5007 emission lines, in each source. The spectral inventory will be utilized primarily to develop prescriptions for obtaining more accurate and precise redshifts, black hole masses, and accretion rates for all quasars. Additionally, the measurements will facilitate an understanding of the dependence of rest-frame ultraviolet-optical spectral properties of quasars on redshift, luminosity, and Eddington ratio, and test whether the physical properties of the quasar central engine evolve over cosmic time.
21746. The GPM catalog
- ID:
- ivo://CDS.VizieR/I/285
- Title:
- The GPM catalog
- Short Name:
- I/285
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- GPM is the newer version of the General Compiled Catalogue of Absolute Proper Motions, derived with respect to galaxies within the plan called Catalogue of Faint Stars (KSZ, Deutch, 1952, Trans. IAU, Vol. 8, 789). The programme was proposed for several observatories of the former Soviet Union, China, Rumania and Spain. There are some resulting individual catalogues of absolute proper motions of stars compiled at five observatories (Kiev, Pulkovo, Moscow, Tashkent and Shanghai). The GPM combines these catalogues and comprises absolute proper motions for 52805 stars from 8 to 15.5mag in 185 fields north of -25 degrees of declination. The size of each region is nearly 1.5 square degrees. The mean standard error of proper motion is 8 mas/yr on average. Detailed information on the construction methodology and input data can be found in (Rybka & Yatsenko, 1997KFNT...13e..70R). In addition to absolute proper motions the GPM contains accurate equatorial coordinates and three-colour B V R photometry for the vast majority of its stars (Rybka 2000KFNT...16e..60R). Additional information was selected from all available sources. Usage of the ACT catalog should provide improved positions (mostly in removing of systematic errors) and improved photometry (because the brightest stars in each GPM region had B and V magnitudes measured by the Tycho experiment on the Hipparcos satellite). The mean accuracies achived, as demonstrated by comparison with above catalogue, are 250 mas for the positions and 0.22mag for B magnitude and 0.26mag for B-V colour. The GPM gives right ascensions and declinations for equinox J2000.0 and epoch copied from available sources. They were only presented to identify the GPM stars with those from other catalogues. The compiled catalogue also presents B magnitudes and B-V colours. They were converted to be close to Johnson system. The Tycho stars were also identified in the GPM catalogue. A search area with a radius of 2 arcseconds was used to search for multiple entries of the same star, which may be appeared in the region overlap areas. The detected entries were then removed from the final catalogue. The procedure decreased the number of stars in the catalogue by about 0.4 %. The adopted catalogue organization includes data in 185 regions sorted according the KSZ region numbers. The data were then sorted nearly in right ascension order within each GPM region. All information needed to associate a point on the sky with region number and provide a more rapid access to that region are given in file region.dat.
21747. The Green Bank Survey
- ID:
- ivo://CDS.VizieR/VIII/53
- Title:
- The Green Bank Survey
- Short Name:
- VIII/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog presents the parts I, II, and III of the Green Bank survey of extragalactic radio sources at 1400 MHz. The data were obtained with the 300' antenna, producing a beamwidth of 10'x11' FWHM. Part I of the survey covers about 521 square degrees of the sky with RA from 7h17m to 16h23m, DEC from +45.8{deg} to +51.7{deg}. 1086 sources are presented down to a limiting flux density of 90 mJy. These data were originally published in Maslowski, 1972, Acta Astronomica, 22, 227 (1972AcA....22..227M). Part II of the survey covers 0.28 sr of the sky with RA from 7h08m to 16h57m, DEC from +31.9{deg} to +39.7{deg}. 2022 sources are presented down to a limiting flux density of 0.09 mJy. Spectral indices between 1400 MHz and 408 MHz are determined for most sources by comparison with the B2 source catalog (Cat.<VIII/36>). These data were originally published in Machalski 1978, Acta Astronomica, 28, 367 (1978AcA....28..367M) Part III of the survey covers an area of 0.099 sr at declinations between 70 and 76.8 degrees. This catalog contains a total of 676 radio sources, of which 502 are statistically complete to 112 mJy. These data were originally published as Rys and Machalski, 1987, Acta Astronomica, 37, 163 (1987AcA....37..163R).
21748. The GSH Binary Survey
- ID:
- ivo://CDS.VizieR/J/AN/338/61
- Title:
- The GSH Binary Survey
- Short Name:
- J/AN/338/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Since 2009 the Grossschwabhausen binary survey is carried out at the University Observatory Jena. This new imaging survey uses available time slots during photometric monitoring campaigns, caused by non-photometric weather conditions, which often exhibit a good atmospheric seeing. The goal of the project is to obtain current relative astrometric measurements of binary systems, that are listed in the Washington Visual Double Star Catalog. In this paper we characterize the target sample of the survey, describe the imaging observations, the astrometric measurements including the astrometric calibration, and present relative astrometric measures of all binaries, which could be obtained in the course of the survey, so far.
- ID:
- ivo://svo.cab/gtc
- Title:
- THE GTC ARCHIVE (USER REDUCED DATA) AT CAB
- Short Name:
- GTC
- Date:
- 28 May 2020 15:39:57
- Publisher:
- Spanish Virtual Observatory
- Description:
- SIAP service for GTC Public Data
- ID:
- ivo://astronet.ru/cas/gsc2_3_2
- Title:
- The Guide Star Catalog II (GSC-II), version 2.3.2
- Short Name:
- gsc2_3_2
- Date:
- 17 Jun 2006 18:44:05
- Publisher:
- Sternberg Astronomical Institute Virtual Observatory Project
- Description:
- The Guide Star Catalog II (GSC-II) is an all-sky optical catalog based on 1" resolution scans of the photographic Sky Survey plates, at two epochs and three bandpasses, from the Palomar and UK Schmidt telescopes. This all-sky catalog will ultimately contains positions, proper motions, classifications, and magnitudes in multiple bandpasses for almost a billion objects down to approximately Jpg=21, Fpg=20. The GSC-II is currently used for HST Bright Object Protection, and will replace GSC-I for HST pointing in cycle 15. Looking ahead, the GSC-II will form the basis of the Guide Star Catalog for JWST. This was constructed in collaboration with ground-based observatories
