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16861. VFTS. B-type stars classification and RV
ID:
ivo://CDS.VizieR/J/A+A/574/A13
Title:
VFTS. B-type stars classification and RV
Short Name:
J/A+A/574/A13
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present spectral classifications for 438 B-type stars observed as part of the VLT-FLAMES Tarantula Survey (VFTS) in the 30 Doradus region of the Large Magellanic Cloud. Radial velocities are provided for 307 apparently single stars, and for 99 targets with radial-velocity variations which are consistent with them being spectroscopic binaries. We investigate the spatial distribution of the radial velocities across the 30 Dor region, and use the results to identify candidate runaway stars. Excluding potential runaways and members of two older clusters in the survey region (SL639 and Hodge301), we determine a systemic velocity for 30 Dor of 271.6+/-12.2km/s from 273 presumed single stars. Employing a 3{sigma} criterion we identify nine candidate runaway stars (2.9% of the single stars with radial-velocity estimates). The projected rotational velocities of the candidate runaways appear to be significantly different to those of the full B-type sample, with a strong preference for either large (>=345km/s) or small (<=65km/s) rotational velocities. Of the candidate runaways, VFTS358 (classified B0.5: V) has the largest differential radial velocity (-106.9+/-16.2km/s), and a preliminary atmospheric analysis finds a significantly enriched nitrogen abundance of 12+log(N/H)> 8.5. Combined with a large rotational velocity (v_e_sini=345+/-22km/s), this is suggestive of past binary interaction for this star.
16862. VFTS. O-type stellar content of 30 Dor
ID:
ivo://CDS.VizieR/J/A+A/564/A40
Title:
VFTS. O-type stellar content of 30 Dor
Short Name:
J/A+A/564/A40
Date:
21 Oct 2021
Publisher:
CDS
Description:
Detailed spectral classifications are presented for 352 O-B0 stars in the VLT-FLAMES Tarantula Survey ESO Large Programme, of which 213 O-type are judged of sufficiently high quality for further morphological analysis. Among them, six subcategories of special interest are distinguished. (1) Several new examples of the earliest spectral types O2-O3 have been found, while a previously known example has been determined to belong to the nitrogen-rich ON2 class. (2) A group of extremely rapidly rotating main-sequence objects has been isolated, including the largest vsini values known, the spatial and radial-velocity distributions of which suggest ejection from the two principal ionizing clusters NGC 2070 and NGC 2060. (3) Several new examples of the evolved, rapidly rotating Onfp class show similar evidence, although at least some of them are spectroscopic binaries. (4) No fewer than 48 members of the Vz category, hypothesized to be on or near the zero-age main sequence, are found in this sample; in contrast to the rapid rotators, they are strongly concentrated to the ionizing clusters and a newly recognized region of current and recent star formation to the north, supporting their interpretation as very young objects, as do their relatively faint absolute magnitudes. (5) A surprisingly large fraction of the main-sequence spectra belong to the recently recognized V((fc)) class, with CIII emission lines of similar strength to the usual NIII in V((f)) spectra, although a comparable number of the latter are also present, as well as six objects with very high-quality data but no trace of either emission feature, presenting new challenges to physical interpretations. (6) Two mid-O Vz and three late-O giant/supergiant spectra with morphologically enhanced nitrogen lines have been detected. Absolute visual magnitudes have been derived for each star with individual extinction laws, and composite Hertzsprung-Russell diagrams provide evidence of the multiple generations present in this field. Spectroscopic binaries, resolved visual multiples, and possible associations with X-ray sources are noted. Astrophysical and dynamical analyses of this unique dataset underway will provide new insights into the evolution of massive stars and starburst clusters.
16863. VFTS. OVz stars in 30 Dor
ID:
ivo://CDS.VizieR/J/A+A/564/A39
Title:
VFTS. OVz stars in 30 Dor
Short Name:
J/A+A/564/A39
Date:
21 Oct 2021
Publisher:
CDS
Description:
OVz stars, a subclass of O-type dwarfs characterized by having HeII{lambda}4686 stronger in absorption than any other helium line in their blue-violet spectra, have been suggested to be on or near the zero-age main sequence (ZAMS). If their youth were confirmed, they would be key objects with which to advance our knowledge of the physical properties of massive stars in the early stages of their lives. We test the hypothesis of OVz stars being at a different (younger) evolutionary stage than are normal O-type dwarfs. We have performed the first comprehensive quantitative spectroscopic analysis of a statistically meaningful sample of OVz and OV stars in the same star-forming region, exploiting the large number of OVz stars identified by the VLT-FLAMES Tarantula Survey in the 30 Doradus region of the Large Magellanic Cloud (LMC). We obtained the stellar and wind parameters of 38 OVz stars (and a control sample of 46 OV stars) using the FASTWIND stellar atmosphere code and the IACOB-GBAT, a grid-based tool developed for automated quantitative analysis of optical spectra of O stars. In the framework of a differential study, we compared the physical and evolutionary properties of both samples, locating the stars in the logg vs. logT_eff_, logQ vs. logT_eff_, and logL/L_{sun}_ vs. logT_eff_ diagrams. We also investigated the predictions of the FASTWIND code regarding the OVz phenomenon.
16864. VGCF detection of galaxy systems
ID:
ivo://CDS.VizieR/J/A+A/444/685
Title:
VGCF detection of galaxy systems
Short Name:
J/A+A/444/685
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of the 48 Voronoi Galaxy Cluster Finder (VGCF) cluster detections. We provide a cluster ID, signal to noise ratios (SNR) in the B, V, R and I bands, positions, angular radius of the cluster, photometric redshift estimates (derived from color-magnitude diagrams (CMD)) and PDCS redshift estimate (Postman et al., 1996AJ....111..615P), if available. Table 5 contains cluster detections in F0028+0515, F0027+0555, F0228+0115 and F0226+0026 fields and other two regions that overlap PDCS 0h and 2h fields.
16865. VHS DR4 - VISTA Hemisphere Survey Data Release 4
ID:
ivo://wfau.roe.ac.uk/vhsDR4-dsa
Title:
VHS DR4 - VISTA Hemisphere Survey Data Release 4
Date:
23 Jan 2024 09:46:50
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VHS will image the entire ~20 000 square degrees of the Southern Sky, with the exception of the areas already covered by the VIKING and VVV surveys, in J and Ks. The resulting data will be about 4 magnitudes deeper than 2MASS and DENIS. The 5000 square degrees covered by the Dark Energy Survey (DES), another imaging survey scheduled to begin in 2010 at the CTIO 4 metre Blanco telescope, will also be observed in H-band. The area around both of the Galactic Caps will be observed in Y- and H- band as well to be combined with the data from the VST ATLAS survey. The main science drivers of the VHS include: examining low mass and nearby stars, studying the merger history of the Galaxy, measuring the properties of Dark Energy through the examination of large-scale structure to a redshift of ~1, and searches for high redshift quasars.
16866. VHS DR3 - VISTA Hemisphere Survey Data Release 3
ID:
ivo://wfau.roe.ac.uk/vhsDR3-dsa
Title:
VHS DR3 - VISTA Hemisphere Survey Data Release 3
Short Name:
VHS DR3
Date:
04 Dec 2019 13:40:01
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VHS will image the entire ~20 000 square degrees of the Southern Sky, with the exception of the areas already covered by the VIKING and VVV surveys, in J and Ks. The resulting data will be about 4 magnitudes deeper than 2MASS and DENIS. The 5000 square degrees covered by the Dark Energy Survey (DES), another imaging survey scheduled to begin in 2010 at the CTIO 4 metre Blanco telescope, will also be observed in H-band. The area around both of the Galactic Caps will be observed in Y- and H- band as well to be combined with the data from the VST ATLAS survey. The main science drivers of the VHS include: examining low mass and nearby stars, studying the merger history of the Galaxy, measuring the properties of Dark Energy through the examination of large-scale structure to a redshift of ~1, and searches for high redshift quasars.
16867. VHS DR2 - VISTA Hemisphere Survey Data Release 2
ID:
ivo://wfau.roe.ac.uk/vhsDR2-dsa
Title:
VHS DR2 - VISTA Hemisphere Survey Data Release 2
Short Name:
VHS DR2
Date:
04 Dec 2019 13:39:51
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VHS will image the entire ~20 000 square degrees of the Southern Sky, with the exception of the areas already covered by the VIKING and VVV surveys, in J and Ks. The resulting data will be about 4 magnitudes deeper than 2MASS and DENIS. The 5000 square degrees covered by the Dark Energy Survey (DES), another imaging survey scheduled to begin in 2010 at the CTIO 4 metre Blanco telescope, will also be observed in H-band. The area around both of the Galactic Caps will be observed in Y- and H- band as well to be combined with the data from the VST ATLAS survey. The main science drivers of the VHS include: examining low mass and nearby stars, studying the merger history of the Galaxy, measuring the properties of Dark Energy through the examination of large-scale structure to a redshift of ~1, and searches for high redshift quasars.
16868. VHS DR1 - VISTA Hemisphere Survey Data Release 1
ID:
ivo://wfau.roe.ac.uk/vhsDR1-dsa
Title:
VHS DR1 - VISTA Hemisphere Survey Data Release 1
Short Name:
VHS DR1
Date:
04 Dec 2019 13:39:40
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VHS will image the entire ~20 000 square degrees of the Southern Sky, with the exception of the areas already covered by the VIKING and VVV surveys, in J and Ks. The resulting data will be about 4 magnitudes deeper than 2MASS and DENIS. The 5000 square degrees covered by the Dark Energy Survey (DES), another imaging survey scheduled to begin in 2010 at the CTIO 4 metre Blanco telescope, will also be observed in H-band. The area around both of the Galactic Caps will be observed in Y- and H- band as well to be combined with the data from the VST ATLAS survey. The main science drivers of the VHS include: examining low mass and nearby stars, studying the merger history of the Galaxy, measuring the properties of Dark Energy through the examination of large-scale structure to a redshift of ~1, and searches for high redshift quasars.
16869. VHS DR6 - VISTA Hemisphere Survey Data Release 6
ID:
ivo://wfau.roe.ac.uk/vhsDR6-dsa
Title:
VHS DR6 - VISTA Hemisphere Survey Data Release 6
Date:
20 Mar 2019 15:52:58
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VHS will image the entire ~20 000 square degrees of the Southern Sky, with the exception of the areas already covered by the VIKING and VVV surveys, in J and Ks. The resulting data will be about 4 magnitudes deeper than 2MASS and DENIS. The 5000 square degrees covered by the Dark Energy Survey (DES), another imaging survey scheduled to begin in 2010 at the CTIO 4 metre Blanco telescope, will also be observed in H-band. The area around both of the Galactic Caps will be observed in Y- and H- band as well to be combined with the data from the VST ATLAS survey. The main science drivers of the VHS include: examining low mass and nearby stars, studying the merger history of the Galaxy, measuring the properties of Dark Energy through the examination of large-scale structure to a redshift of ~1, and searches for high redshift quasars.
16870. VI and CMT1 photometry of NGC 2627
ID:
ivo://CDS.VizieR/J/MNRAS/346/390
Title:
VI and CMT1 photometry of NGC 2627
Short Name:
J/MNRAS/346/390
Date:
21 Oct 2021
Publisher:
CDS
Description:
Charge-coupled device (CCD) photometry in the Johnson V, Kron-Cousins I and Washington CMT1 systems is presented in the field of the poorly known open cluster NGC 2627.

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