- ID:
- ivo://CDS.VizieR/J/MNRAS/400/1962
- Title:
- Southern GEMS groups. II.
- Short Name:
- J/MNRAS/400/1962
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the neutral hydrogen (HI) content of 16 groups for which we have multiwavelength data including X-ray observations. Wide-field imaging of the groups was obtained with the 20cm multibeam system on the 64m Parkes telescope. We have detected 10 previously uncatalogued HI sources, one of which has no visible optical counterpart. We examine the HI properties of the groups, compared to their X-ray characteristics, finding that those groups with a higher X-ray temperature and luminosity contain less HI per galaxy.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/440/1061
- Title:
- Southern red high proper motion objects
- Short Name:
- J/A+A/440/1061
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of spectroscopic follow-up observations for a sample of 71 red objects with high proper motions in the range 0.08-1.14 arcsec/yr as detected using APM and SuperCOSMOS Sky Surveys (SSS) measurements of multi-epoch photographic Schmidt plates. Red objects were selected by combining the photographic BjRI magnitudes with 2MASS near-infrared JHKs magnitudes. Some 50 of the 71 spectroscopically classified objects turn out to be late-type (>M6) dwarfs and in more detail, the sample includes 35 ultracool dwarfs with spectral types between M8 and L2, some previously reported, as well as five M-type subdwarfs, including a cool esdM6 object, SSSPM J0500-5406. Distance estimates based on the spectral types and 2MASS J magnitudes place almost all of the late-type (>M6) dwarfs within 50pc, with 25 objects located inside the 25pc limit of the catalogue of nearby stars. Most of the early-type M dwarfs are located at larger distances of 100-200pc, suggesting halo kinematics for some of them. All objects with Halpha equivalent widths larger than 10 Angstroms have relatively small tangential velocities (<50km/s). Finally, some late-type but blue objects are candidate binaries.
- ID:
- ivo://CDS.VizieR/J/AJ/89/1897
- Title:
- Southern stars of high radial velocity
- Short Name:
- J/AJ/89/1897
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Slit spectra have been obtained for 82 stars for which the objective-prism radial-velocity catalogue of Stock lists velocities over 130km/s in magnitude. The slit spectra reveal that many of these objects are F-K stars of low metal abundance, including some stars apparently as metal weak as any presently known. Radial velocities were derived from the slit spectra to examine the reliability of the large objective-prism velocities. The slit results confirm that the majority of the stars are indeed of high velocity, but show that the objective-prism technique tends to produce velocities systematically too large in magnitude by about 40km/s. It was also found that a large objective-prism velocity that is of low weight or from spectra near a plate edge is likely spurious. A search of the 10000 entries in Stock's catalogue yields 205 objects with radial-velocity magnitudes over 130km/s. Sixty-three of these velocities are not suspect because of low weight or edge proximity. An additional 14 stars of lower quality prism velocities were confirmed to have high velocities from the slit spectra. The high-velocity stars appear to form two distinct groups: metal-weak F-K stars and spectroscopically normal main-sequence A stars. Slit spectra were obtained on six nights in April 1978 utilizing the Boller and Chivens spectrograph and the Carnegie image tube at the Cassegrain focus of the 1-m Yale telescope at CTIO.
- ID:
- ivo://CDS.VizieR/J/AJ/158/167
- Title:
- Speckle observations & orbits of multiple stars
- Short Name:
- J/AJ/158/167
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report results of speckle-interferometric monitoring of visual hierarchical systems using the newly commissioned instrument NN-EXPLORE Exoplanet and Stellar Speckle Imager at the 3.5 m WIYN telescope. During one year, 390 measurements of 129 resolved subsystems were made, while some targets were unresolved. Using our astrometry and archival data, we computed 36 orbits (27 for the first time). Spectro-interferometric orbits of seven pairs are determined by combining positional measurements with radial velocities measured, mostly, with the Center for Astrophysics digital speedometers. For the hierarchical systems HIP 65026 (periods 49 and 1.23 yr) and HIP 85209 (periods 34 and 1.23 yr) we determined both the inner and the outer orbits using astrometry and radial velocities and measured the mutual orbit inclinations of 11.3{deg}+/-1.0{deg} and 12.0{deg}+/-3.0{deg}, respectively. Four bright stars are resolved for the first time; two of those are triple systems. Several visual subsystems announced in the literature are shown to be spurious. We note that subsystems in compact hierarchies with outer separations less than 100 au tend to have less eccentric orbits compared to wider hierarchies.
- ID:
- ivo://CDS.VizieR/J/A+A/570/A2
- Title:
- Spectra and radial velocities of nuclear stars
- Short Name:
- J/A+A/570/A2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Within the central 10pc of our Galaxy lies a dense cluster of stars. This nuclear star cluster forms a distinct component of the Galaxy, and similar nuclear star clusters are found in most nearby spiral and elliptical galaxies. Studying the structure and kinematics of nuclear star clusters reveals the history of mass accretion and growth of galaxy nuclei and central massive black holes. Because the Milky Way nuclear star cluster is at a distance of only 8 kpc, we can spatially resolve the cluster on sub-parsec scales. This makes the Milky Way nuclear star cluster a reference object for understanding the formation of all nuclear star clusters.
- ID:
- ivo://CDS.VizieR/J/AZh/81/333
- Title:
- Spectral analysis of V510 Pup
- Short Name:
- J/AZh/81/333
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a detailed identification of lines in the optical spectrum of the post-AGB star V510Pup associated with the infrared source IRAS08005-2356. Absorbtion lines of the ions FeII, TiII, CrII, YII are presented at wavelengths from 4549 to 8546 A. The absorptions YII and other s-process elements are anomalously strong. There is also strong in the circumstellar C_2_ Swan bands. The profiles of most of the lines (of hydrogen and metals) display absorption-emission P Cyg type profiles. All the absorption lines are shifted toward shorter wavelengths, suggesting an outflow of stellar material. The expansion velocity of the envelope derived from the Swan bands arising there is Vexp=42km/s. The highest wind velocity determined from the absorptional wings of FeII(42) P Cygni profiles reachs 240km/s. Based on the star's kinematic characteristics and the amount of interstellar absorption, the distance to this object is d~3-4kpc.
- ID:
- ivo://CDS.VizieR/J/other/AstBu/65.150
- Title:
- Spectral line identification in 3 Pup
- Short Name:
- J/other/AstBu/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Optical spectra taken in 1997-2008 are used to analyze the spectral peculiarities and velocity field in the atmosphere of the peculiar supergiant 3 Pup.
- ID:
- ivo://CDS.VizieR/J/A+AS/131/295
- Title:
- Spectral survey of Case emission-line galaxies
- Short Name:
- J/A+AS/131/295
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of the follow-up spectroscopy of 178 emission-line galaxy (ELG) candidates from the Case objective-prism survey and nine Markarian galaxies with the 6m telescope are described. Only the candidates classified in the Case survey as those with emission lines were observed with the aim to form a statistical sample of blue compact galaxies (BCGs) with strong emission lines in the zone RA: 8h-16h, and DE: =+29deg-+38deg. We present the redshifts, equivalent widths and flux ratios for the strongest lines and the spectrum type for most of the galaxies with detected emission lines. A significant fraction (about 23%) of the observed Case galaxies do not show emission lines in blue. Preliminary analysis of the data is presented and the properties of the observed ELGs are compared with those of other known samples.
- ID:
- ivo://CDS.VizieR/J/ApJ/888/54
- Title:
- Spectra of a rare low-mass Wolf-Rayet star in LMC
- Short Name:
- J/ApJ/888/54
- Date:
- 25 Oct 2021 10:12:43
- Publisher:
- CDS
- Description:
- We report the serendipitous discovery of an object, UVQSJ060819.93-715737.4, with a spectrum dominated by extremely intense, narrow CII emission lines. The spectrum is similar to those of the very rare, late-type [WC11] low-mass Wolf-Rayet stars. Despite the recognition of these stars as a distinct class decades ago, there remains barely a handful of Galactic members, all of which are also planetary-nebula central stars. Although no obvious surrounding nebulosity is present in J0608, [OII], [NII], and [SII] emission suggest the presence of an inconspicuous, low-excitation nebula. There is low-amplitude incoherent photometric variability on timescales of days to years, as well as numerous prominent P Cygni profiles, implying mass loss. There are indications of a binary companion. The star is located on the outskirts of the LMC, and the observed radial velocity (~+250km/s) and proper motion strongly suggest membership. If indeed an LMC member, this is the first extragalactic late [WC] star, and the first with an accurately determined luminosity, as the Galactic examples are too distant for precise parallax determinations. A high-quality, broad-coverage spectrum of the prototype of the late [WC] class, CPD -56 8032, is also presented. We discuss different excitation mechanisms capable of producing the great strength of the CII emission. Numerous autoionizing levels of C II are definitely populated by processes other than dielectronic recombination. Despite the spectacular emission spectra, observational selection makes objects such as these difficult to discover. Members of the [WC11] class may in fact be considerably more common than the handful of previously known late [WC] stars.
1800. Spectra of HD 120678
- ID:
- ivo://CDS.VizieR/J/A+A/546/A92
- Title:
- Spectra of HD 120678
- Short Name:
- J/A+A/546/A92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the detection of a shell-like event in the Oe-type star HD 120678. HD 120678 has been intensively observed as part of a high-resolution spectroscopic monitoring program of southern Galactic O stars and Wolf-Rayet stars of the nitrogen sequence. An optical spectrogram of HD 120678 obtained in June 2008 shows strong H and HeI absorption lines instead of the double-peaked emission profiles observed both previously and subsequently, as well as a variety of previously undetected absorption features, mainly of OII, SiIII and FeIII. Photometric data reveal that the development of the absorption spectrum coincided with a remarkable dip in the V-band lightcurve. The "shell phase" of HD 120678 did not persist for very long: the V magnitude recovered its previous average value in fewer than 120 days, whereas H and He emission lines became detectable one year later. Similar spectral variations have been observed in a few Be stars, and they are usually interpreted as changes in the circumstellar disk.
