- ID:
- ivo://CDS.VizieR/J/A+A/584/A2
- Title:
- KMOS view of the Galactic centre. I.
- Short Name:
- J/A+A/584/A2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galactic centre hosts a crowded, dense nuclear star cluster with a half-light radius of 4pc. Most of the stars in the Galactic centre are cool late-type stars, but there are also >=100 hot early-type stars in the central parsec of the Milky Way. These stars are only 3-8Myr old. Our knowledge of the number and distribution of early-type stars in the Galactic centre is incomplete. Only a few spectroscopic observations have been made beyond a projected distance of 0.5pc of the Galactic centre. The distribution and kinematics of early-type stars are essential to understand the formation and growth of the nuclear star cluster.
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- ID:
- ivo://CDS.VizieR/J/other/RAA/16.138
- Title:
- LAMOST catalog of early-type emission-line stars
- Short Name:
- J/other/RAA/16.1
- Date:
- 10 Dec 2021 14:42:33
- Publisher:
- CDS
- Description:
- We present a catalog including 11204 spectra of 10436 early-type emission-line stars from LAMOST DR2, among which 9752 early-type emission-line spectra are newly discovered. For these early-type emission-line stars, we discuss the morphological and physical properties of their low-resolution spectra. In this spectral sample, the H{alpha} emission profiles display a wide variety of shapes. Based on the H{alpha} line profiles, these spectra are categorized into five distinct classes: single-peak emission, single-peak emission in absorption, double-peak emission, double-peak emission in absorption, and P-Cygni profiles. To better understand what causes the H{alpha} line profiles, we divide these objects into four types from the perspective of physical classification, which include classical Be stars, Herbig Ae/Be stars, close binaries and spectra contaminated by HII regions. The majority of Herbig Ae/Be stars and classical Be stars are identified and separated using a (H-K, K-W1) color-color diagram.We also discuss 31 binary systems that are listed in the SIMBAD on-line catalog and identify 3600 spectra contaminated by HII regions after cross-matching with positions in the Dubout-Crillon catalog (1976, Cat. J/A+AS/25/25. A statistical analysis of line profiles versus classifications is then conducted in order to understand the distribution of H{alpha} profiles for each type in our sample. Finally, we also provide a table of 172 spectra with FeII emission lines and roughly calculate stellar wind velocities for seven spectra with P-Cygni profiles.
- ID:
- ivo://CDS.VizieR/J/A+A/593/A112
- Title:
- LHA 120-S 73 optical and NIR spectra
- Short Name:
- J/A+A/593/A112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- B[e] supergiants are evolved massive stars, enshrouded in a dense wind and surrounded by a molecular and dusty disk. The mechanisms that drive phases of enhanced mass loss and mass ejections, responsible for the shaping of the circumstellar material of these objects, are still unclear. We aim to improve our knowledge on the structure and dynamics of the circumstellar disk of the Large Magellanic Cloud B[e] supergiant LHA 120-S 73. High-resolution optical and near-infrared spectroscopic data were obtained over a period of 16 and 7 yr, respectively. The spectra cover the diagnostic emission lines from [CaII] and [OI], as well as the CO bands. These features trace the disk at different distances from the star. We analyzed the kinematics of the individual emission regions by modeling their emission profiles. A low-resolution mid-infrared spectrum was obtained as well, which provides information on the composition of the dusty disk.
- ID:
- ivo://CDS.VizieR/J/AJ/128/1233
- Title:
- LkH{alpha} 101 and the young cluster in NGC 1579
- Short Name:
- J/AJ/128/1233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The central region of the dark cloud L1482 is illuminated by LkH{alpha} 101, a heavily reddened (A_V_~10mag) high-luminosity (>=8x10^3^L_Sun_) star having an unusual emission-line spectrum plus a featureless continuum. About 35 much fainter (mostly between R=16 and >21) H{alpha} emitters have been found in the cloud. Their color-magnitude distribution suggests a median age of about 0.5Myr, with considerable dispersion. There are also at least five bright B-type stars in the cloud, presumably of about the same age; none show the peculiarities expected of HAeBe stars. Dereddened, their apparent V magnitudes lead to a distance of about 700pc. Radio observations suggest that the optical object LkH{alpha} 101 is in fact a hot star surrounded by a small H II region, both inside an optically thick dust shell.
- ID:
- ivo://CDS.VizieR/J/A+A/555/A141
- Title:
- LMC emission-line stars. Armagh survey
- Short Name:
- J/A+A/555/A141
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate astrometry is required to reliably cross-match 20th-century photographic catalogues against 21st-century digital surveys. The present work provides modern-area identifications and astrometry for the 801 emission-line objects "of stellar appearance" in the Armagh survey (the largest of its nature to date). Targets have been individually identified in digital images using the Armargh Atlas and, in most cases, unambiguously matched to entries in the UCAC astrometric catalogues.
- ID:
- ivo://CDS.VizieR/J/A+A/284/515
- Title:
- Long-term periodic variability in gamma Cas
- Short Name:
- J/A+A/284/515
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/other/NewA/10.325
- Title:
- 2MASS observations of Be stars
- Short Name:
- J/other/NewA/10.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A catalogue of almost all known Galactic Be stars in the 2MASS (<II/246>) database (1185 in total) and in the MSX (<V/114>) database (225 in total) is presented in this paper. From the color-color diagrams and spectral indexes, it is found that the IR excesses for many samples are due to free-free and free-bound emission from the ionized material around a Be star as suggested previously and that the mean spectral index derived for the samples is 1.50+/-0.34 between J to K bands and 1.14+/-0.42 between K to A bands, respectively. However, it is also found that there are eight Be stars that have large near infrared excess emission with spectral index values outside the range expected for freefree and freebound emission. This is likely attributed to circumstellar dust emission.
- ID:
- ivo://CDS.VizieR/J/MNRAS/473/4130
- Title:
- M31 center emission-line point-like sources
- Short Name:
- J/MNRAS/473/4130
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed description of the wavelength, astrometric and photometric calibration plan for SITELLE, the imaging Fourier transform spectrometer attached to the Canada-France-Hawaii telescope, based on observations of a red (647-685nm) data cube of the central region (11'x11') of the Andromeda galaxy. The first application, presented in this paper, is a radial-velocity catalogue (with uncertainties of ~2-6km/s) of nearly 800 emission-line point-like sources, including ~450 new discoveries. Most of the sources are likely planetary nebulae, although we also detect five novae (having erupted in the first 8 months of 2016) and one new supernova remnant candidate.
79. MHO Catalogue
- ID:
- ivo://CDS.VizieR/J/A+A/511/A24
- Title:
- MHO Catalogue
- Short Name:
- J/A+A/511/A24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of Molecular Hydrogen emission-line Objects (MHOs) in outflows from young stars, most of which are deeply embedded. All objects are identified in the near-infrared lines of molecular hydrogen, all reside in the Milky Way, and all are associated with jets or molecular outflows. Objects in both low and high-mass star forming regions are included. This catalogue complements the existing database of Herbig-Haro objects; indeed, for completeness, HH objects that are detected in H_2_ emission are included in the MHO catalogue.
- ID:
- ivo://CDS.VizieR/J/A+A/531/A50
- Title:
- 1.3mm and 3mm emission maps or 4 Ae/Be stars
- Short Name:
- J/A+A/531/A50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Herbig Ae stars (HAe) are the precursors of Vega-type systems and, therefore, crucial objects in planet formation studies. Thus far, only a few disks associated with HAe stars have been studied using millimetre interferometers. Our aim is to determine the dust evolution and the lifetime of the disks associated with Herbig Ae stars. We imaged the continuum emission at ~3mm and ~1.3mm of the Herbig Ae/Be stars BD+61154, RR Tau, VY Mon and LkH{alpha} 198 using the Plateau de Bure Interferometer (PdBI). These stars are in the upper end of the stellar mass range of the Herbig Ae stars (M_*_>3M_{sun}_). Our measurements were used to complete the Spectral Energy Distribution (SED). The modelling of the SED, in particular the FIR-mm part, allow us to determine the masses and dust properties of these disks. We detected the disks associated with BD+61154, RR Tau and VY Mon with disk masses of 0.35M_{sun}_, 0.05M_{sun}_ and 0.40M_{sun}_ respectively. The disk around LkH{alpha} 198 was not detected with an upper limit to the disk mass of 0.004M_{sun}_. We detected, however, the disks associated with the younger stellar objects LkH{alpha} 198--IR and LkH{alpha} 198--mm that are located in the vicinity of LkH{alpha} 198. The fitting of the mm part of the SED reveal that the grains in the mid-plane of the disks around BD+61154, RR Tau and VY Mon have sizes of ~1-1000um. Therefore, grains have not grown to centimetre sizes in these disks yet. These massive (M_*_>3M_{sun}_) and young (~1Myr) HAe stars are surrounded by massive (>~0.04M_{sun}_) disks with grains of micron-millimetre sizes. Although grain growth is proceeding in these disks, their evolutionary stage is prior to the formation of planetesimals. These disks are less evolved than those detected around T Tauri and Herbig Be stars.
