- ID:
- ivo://CDS.VizieR/I/344
- Title:
- The URAT Parallax Catalog (UPC). Update 2018
- Short Name:
- I/344
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- United States Naval Observatory (USNO) Robotic Astrometric Telescope (URAT) Parallax Catalog south (UPCs) and north (UPCn). These data are based on the accepted paper for the Astronomical Journal (2018) by C. Finch, N. Zacharias, and W.-C. Jao, "URAT south parallax results: discovery of new nearby stars" (2018AJ....155..176F). The southern data are new, while the northern data contain a subset of the previously published UPC catalog after applying the more stringent selection criteria of the south data and supplementing the data with columns of the southern data. The previously published URAT Parallax Catalog (UPC) paper is: C. Finch and N. Zacharias (2016AJ....151..160F, Cat. J/AJ/151/160) (arXiv:1604.06739).
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Search Results
- ID:
- ivo://CDS.VizieR/III/250
- Title:
- The VIMOS VLT deep survey (VVDS-DEEP)
- Short Name:
- III/250
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/ApJS/233/3
- Title:
- The VLBA Extragalactic Proper Motion Catalog
- Short Name:
- J/ApJS/233/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of extragalactic proper motions created using archival VLBI data and our own VLBA astrometry. The catalog contains 713 proper motions, with average uncertainties of ~24{mu}as/yr, including 40 new or improved proper motion measurements using relative astrometry with the VLBA. The observations were conducted in the X-band and yielded positions with uncertainties of ~70{mu}as. We add 10 new redshifts using spectroscopic observations taken at Apache Point Observatory and Gemini North. With the VLBA Extragalactic Proper Motion Catalog, we detect the secular aberration drift-the apparent motion of extragalactic objects caused by the solar system's acceleration around the Galactic center-at a 6.3{sigma} significance. We model the aberration drift as a spheroidal dipole, with the square root of the power equal to 4.89+/-0.77{mu}as/yr, an amplitude of 1.69+/-0.27{mu}as/yr, and an apex at (275.2{deg}+/-10.0{deg}, -29.4{deg}+/-8.8{deg}). Our dipole model detects the aberration drift at a higher significance than some previous studies, but at a lower amplitude than expected or previously measured. The full aberration drift may be partially removed by the no-net-rotation constraint used when measuring archival extragalactic radio source positions. Like the cosmic microwave background dipole, which is induced by the observer's motion, the aberration drift signal should be subtracted from extragalactic proper motions in order to detect cosmological proper motions, including the Hubble expansion, long-period stochastic gravitational waves, and the collapse of large-scale structure.
- ID:
- ivo://CDS.VizieR/J/ApJ/864/11
- Title:
- The VVV Variables (V^4^) catalog
- Short Name:
- J/ApJ/864/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Time-varying phenomena are one of the most substantial sources of astrophysical information, and their study has led to many fundamental discoveries in modern astronomy. We have developed an automated tool to search for and analyze variable sources in the near-infrared Ks band using the data from the VISTA Variables in the Via Lactea (VVV) ESO Public Large Survey. This process relies on the characterization of variable sources using different variability indices calculated from time series generated with point-spread function (PSF) photometry of sources under analysis. In particular, we used two main indices, the total amplitude {Delta}Ks and the eta index {eta}, to identify variable sources. Once the variable objects are identified, periods are determined with generalized Lomb-Scargle periodograms and the information potential metric. Variability classes are assigned according to a compromise between comparisons with VVV templates and the period of the variability. The automated tool is applied on VVV tiles d001 and d002 and led to the discovery of 200 variable sources. We detected 70 irregular variable sources and 130 periodic ones. In addition, nine open-cluster candidates projected in the region are analyzed, and the infrared variable candidates found around these clusters are further scrutinized by cross-matching their locations against emission star candidates from VPHAS+ survey H{alpha} color cuts.
3845. The WIRED survey. II.
- ID:
- ivo://CDS.VizieR/J/ApJS/197/38
- Title:
- The WIRED survey. II.
- Short Name:
- J/ApJS/197/38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With the launch of the Wide-field Infrared Survey Explorer (WISE), a new era of detecting planetary debris and brown dwarfs (BDs) around white dwarfs (WDs) has begun with the WISE InfraRed Excesses around Degenerates (WIRED) Survey. The WIRED Survey is sensitive to substellar objects and dusty debris around WDs out to distances exceeding 100pc, well beyond the completeness level of local WDs. In this paper, we present a cross-correlation of the preliminary Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) WD catalog between the WISE, Two-Micron All Sky Survey (2MASS), UKIRT Infrared Deep Sky Survey (UKIDSS), and SDSS DR7 photometric catalogs. From ~18000 input targets, there are WISE detections comprising 344 "naked" WDs (detection of the WD photosphere only), 1020 candidate WD+M dwarf binaries, 42 candidate WD+BD systems, 52 candidate WD+dust disk systems, and 69 targets with indeterminate infrared excess. We classified all of the detected targets through spectral energy distribution model fitting of the merged optical, near-IR, and WISE photometry. Some of these detections could be the result of contaminating sources within the large (~6") WISE point-spread function; we make a preliminary estimate for the rates of contamination for our WD+BD and WD+disk candidates and provide notes for each target of interest.
- ID:
- ivo://CDS.VizieR/J/ApJ/733/123
- Title:
- The Wolf-Rayet content of M33 (NGC 598)
- Short Name:
- J/ApJ/733/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Wolf-Rayet (WR) stars are evolved massive stars, and the relative number of WC-type and WN-type WRs should vary with metallicity, providing a sensitive test of stellar evolutionary theory. The observed WC/WN ratio is much higher than that predicted by theory in some galaxies but this could be due to observational incompleteness for WN types, which have weaker lines. Previous studies of M33's WR content show a galactocentric gradient in the relative numbers of WCs and WNs, but only small regions have been surveyed with sufficient sensitivity to detect all of the WNs. Here, we present a sensitive survey for WRs covering all of M33, finding 55 new WRs, mostly of WN type. Our spectroscopy also improves the spectral types of many previously known WRs, establishing in one case that the star is actually a background quasar. The total number of spectroscopically confirmed WRs in M33 is 206, a number we argue is complete to ~5%, with most WRs residing in OB associations, although ~2% are truly isolated.
- ID:
- ivo://CDS.VizieR/J/ApJ/716/348
- Title:
- The XMM-Newton survey of the COSMOS field
- Short Name:
- J/ApJ/716/348
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the final optical identifications of the medium-depth (~60ks), contiguous (2deg^2^) XMM-Newton survey of the COSMOS field. XMM-Newton has detected ~1800 X-ray sources down to limiting fluxes of ~5x10^-16^, ~3x10^-15^, and ~7x10^-15^erg/cm^2^/s in the 0.5-2keV, 2-10keV, and 5-10keV bands, respectively (~1x10^-15^, ~6x10^-15^, and ~1x10^-14^erg/cm^2^/s, in the three bands, respectively, over 50% of the area). The work is complemented by an extensive collection of multiwavelength data from 24um to UV, available from the COSMOS survey, for each of the X-ray sources, including spectroscopic redshifts for >~50% of the sample, and high-quality photometric redshifts for the rest. The XMM and multiwavelength flux limits are well matched: 1760 (98%) of the X-ray sources have optical counterparts, 1711 (~95%) have IRAC counterparts, and 1394 (~78%) have MIPS 24um detections. Spectroscopically identified obscured and unobscured AGNs, as well as normal and star-forming galaxies, present well-defined optical and infrared properties. We devised a robust method to identify a sample of ~150 high-redshift (z>1), obscured AGN candidates for which optical spectroscopy is not available.
- ID:
- ivo://CDS.VizieR/J/ApJ/750/97
- Title:
- The yellow and red supergiants of M33
- Short Name:
- J/ApJ/750/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Yellow and red supergiants are evolved massive stars whose numbers and locations on the Hertzsprung-Russell (H-R) diagram can provide a stringent test for models of massive star evolution. Previous studies have found large discrepancies between the relative number of yellow supergiants (YSGs) observed as a function of mass and those predicted by evolutionary models, while a disagreement between the predicted and observed locations of red supergiants (RSGs) on the H-R diagram was only recently resolved. Here, we extend these studies by examining the YSG and RSG populations of M33. Unfortunately, identifying these stars is difficult as this portion of the color-magnitude diagram is heavily contaminated by foreground dwarfs. We identify the RSGs through a combination of radial velocities and a two-color surface gravity discriminant, and after re-characterizing the rotation curve of M33 with our newly selected RSGs, we identify the YSGs through a combination of radial velocities and the strength of the OI{lambda}7774 triplet. We examine ~1300 spectra in total and identify 121 YSGs (a sample that is unbiased in luminosity above log(L/L_{sun}_)~4.8) and 189 RSGs. After placing these objects on the H-R diagram, we find that the latest generation of Geneva evolutionary tracks shows excellent agreement with the observed locations of our RSGs and YSGs, the observed relative number of YSGs with mass, and the observed RSG upper mass limit.
- ID:
- ivo://CDS.VizieR/J/ApJ/497/736
- Title:
- The young cluster IC 348.
- Short Name:
- J/ApJ/497/736
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD photometry in BVRI was obtained for about 260 stars in and around IC 348, and multiobject spectroscopy for 80 of these. A somewhat larger region was surveyed for stars having H{alpha} in emission; over 110 emission-line stars brighter than about R=19 were discovered. Because H{alpha}emission could be detected to a limit near W=3{AA}, division into weak-line (WTTSs) and classical T Tauri stars (CTTSs) was possible on purely spectroscopic grounds. There is a steep rise in the number of emission-line stars below W(H{alpha})=10{AA}; the proportion of WTTSs to CTTSs in the area surveyed is 58:51. ROSAT detected only about 58% of the spectroscopic WTTSs and about 65% of the CTTSs, although these numbers are sensitive to the survey thresholds. The bulk of the ages of about 100 stars, read off the theoretical tracks of D'Antona & Mazzitelli (1994ApJS...90..467D), range between about 0.7 and 12Myr, but the emission-line stars, which are most likely to be members of IC 348, have a mean age of 1.3Myr. Allowance for unresolved binaries would increase this somewhat, but there is a firm upper limit at 2.95Myr. There is no indication that the ages of the emission-line stars depend upon W(H{alpha}): the IC 348 WTTSs as a population are not systematically older than the CTTSs, but there is a tendency for the WTTSs to be concentrated toward the center of IC 348, while the CTTSs are more widely distributed. There is a scattering of emission-H{alpha} stars over the entire area surveyed. There are too many to be explained as low-mass members of an earlier generation of star formation in Per OB2 or as foreground dMe stars. The mass frequency function, based on some 125 stars fitted to theoretical tracks, rises from 1.5M_{sun}_; to about 0.2M_{sun}_;, with a slope very much like that of the Scalo initial mass function. The optical cluster IC 348 radius is about 4.0', or 0.37pc. The total mass of optically detectable stars in this volume is 57M_{sun}_;, while the mean space density is about 520 stars/pc^3^. The amount of interstellar material remaining within the cluster is small in comparison. Star formation in the Per OB2/IC 348 region cannot be characterized by one unique age; it appears that stars have been forming in the region now occupied by the association for 10-20Myr.
- ID:
- ivo://CDS.VizieR/J/MNRAS/466/3636
- Title:
- The young open cluster NGC 7067
- Short Name:
- J/MNRAS/466/3636
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NGC 7067 is a young open cluster located in the direction between the first and the second Galactic quadrants and close to the Perseus spiral arm. This makes it useful for studies of the nature of the Milky Way spiral arms. Stromgren photometry taken with the Wide Field Camera at the Isaac Newton Telescope allowed us to compute individual physical parameters for the observed stars and hence to derive the cluster's physical parameters. Spectra from the 1.93-m telescope at the Observatoire de Haute-Provence helped to check and improve the results. We obtained photometry for 1233 stars, individual physical parameters for 515 and spectra for 9 of them. The 139 selected cluster members lead to a cluster distance of 4.4+/-0.4kpc, with an age below log10(t(yr))=7.3 and a present mass of 1260+/-160M_{sun}_. The morphology of the data reveals that the centre of the cluster is at (RA, DE) = (21:24:13.69, +48:00:39.2) J2000, with a radius of 6.1-arcmin. Stromgren and spectroscopic data allowed us to improve the previous parameters available for the cluster in the literature.
