- ID:
- ivo://CDS.VizieR/J/MNRAS/437/532
- Title:
- VY CMa molecular line spectra
- Short Name:
- J/MNRAS/437/532
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the far-infrared and submillimetre molecular emission-line spectrum of the luminous M-supergiant VY CMa, observed with the Spectral and Photometric Imaging Receiver (SPIRE) and Photodetector Array Camera and Spectrometer for Herschel spectrometers aboard the Herschel Space Observatory. Over 260 emission lines were detected in the 190-650{mu}m SPIRE Fourier Transform Spectrometer spectra, with one-third of the observed lines being attributable to H_2_O. Other detected species include CO, ^13^CO, H_2_O, SiO, HCN, SO, SO2, CS, H_2_S and NH_3_. Our model fits to the observed ^12^CO and ^13^CO line intensities yield a ^12^C/^13^C ratio of 5.6+/-1.8, consistent with measurements of this ratio for other M-supergiants, but significantly lower than previously estimated for VY CMa from observations of lower-J lines. The spectral line energy distribution for 20 SiO rotational lines shows two temperature components: a hot component at ~1000K, which we attribute to the stellar atmosphere and inner wind, plus a cooler ~200K component, which we attribute to an origin in the outer circumstellar envelope. We fit the line fluxes of ^12^CO, ^13^CO, H_2_O and SiO, using the smmol non-local thermodynamic equilibrium (LTE) line transfer code, with a mass-loss rate of 1.85x10^-4^M_{sun}_/yr between 9R* and 350R*. We also fit the observed line fluxes of ^12^CO, ^13^CO, H_2_O and SiO with smmol non-LTE line radiative transfer code, along with a mass-loss rate of 1.85x10^-4^M_{sun}_/yr. To fit the high rotational lines of CO and H_2_O, the model required a rather flat temperature distribution inside the dust condensation radius, attributed to the high H_2_O opacity. Beyond the dust condensation radius the gas temperature is fitted best by an r-0.5 radial dependence, consistent with the coolant lines becoming optically thin. Our H_2_O emission-line fits are consistent with an ortho:para ratio of 3 in the outflow.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/617/A16
- Title:
- VY Scl reduced spectra & radial velocities
- Short Name:
- J/A+A/617/A16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the context of a large campaign to determine the system parameters of high mass transfer cataclysmic variables, we found VY Scl in a low state in 2008. Making use of this low state, we study the stellar components of the binary with little influence of the normally dominating accretion disc. Time-resolved spectroscopy and photometry of VY Scl taken during the low state are presented. We analysed the light-curve and radial velocity curve and use time-resolved spectroscopy to calculate Doppler maps of the dominant emission lines. The spectra show narrow emission lines of Halpha, Hbeta, HeI, NaI D, and FeII, as well as faint TiO absorption bands that trace the motion of the irradiated secondary star, and Halpha and HeI emission line wings that trace the motion of the white dwarf. From these radial velocities, we find an orbital period of 3.84h, and put constraints on binary parameters such as the mass ratio M2/M1 of 0.43 and the inclination of 15. With a secondary mass between 0.3 and 0.35M_{sun}_, we derive the mass for the white dwarf as M1=0.6-1.1M_{sun}_.
- ID:
- ivo://CDS.VizieR/III/13
- Title:
- Vyssotsky's Catalogues 1950.0
- Short Name:
- III/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog includes the results of a complete survey of the McCormick objective prism plates for M dwarf stars. catalog.dat includes identifications, magnitudes, proper motions in RA and Dec, spectral types and parallaxes.
- ID:
- ivo://nasa.heasarc/wackerling
- Title:
- Wackerling Catalog of Early-Type Emission-Line Stars
- Short Name:
- Wackerling
- Date:
- 14 Feb 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Wackerling Catalog contains entries for 5326 early-type emission-line stars. Of these stars, 1424 have no spectral classification but are assumed to be of early type. Some 71 percent of the stars in this catalog can also be found in the Mount Wilson and the Mount Wilson-Michigan survey catalogs. The Wackerling Catalog contains numerous cross identifications to other designations (common name, HD, DM, LS, MWC, TON, HIL, WRA, HEN, etc.), rough spectroscopic types, magnitudes (visual and blue), and positions. The version of the Wackerling Catalog on which the HEASARC database is based was obtained from the ADC and differs in some respects from the original published version, notice. This online catalog was originally ingested by the HEASARC in July 1999, based on a machine-readable table obtained from the ADC/CDS data centers. It was updated in May 2020 to reflect updates to the spect_type_code values made by the CDS for improved database compatibility. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/A+A/577/A127
- Title:
- W49A JCMT Spectral Legacy Survey spectroscopy
- Short Name:
- J/A+A/577/A127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The massive and luminous star-forming region W49A is a well-known Galactic candidate to probe the physical conditions and chemistry similar to those expected in external starburst galaxies. We aim to probe the physical and chemical structure of W49A on a spatial scale of ~0.8pc based on the JCMT Spectral Legacy Survey, which covers the frequency range between 330 and 373GHz. The wide 2x2-arcmin field and the high spectral resolution of the HARP instrument on JCMT provides information on the spatial structure and kinematics of the cloud traced by the observed molecular lines. For species where multiple transitions are available, we estimate excitation temperatures and column densities using a population diagram method that takes beam dilution and optical depth corrections into account. We detected 255 transitions corresponding to 63 species in the 330-373GHz range at the center position of W49A. Excitation conditions can be probed for 14 molecules, including the complex organic molecules CH_3_CCH, CH_3_CN, and CH_3_OH. The chemical composition suggests the importance of shock, photon-dominated region (PDR), and hot core chemistry. Many molecular lines show a significant spatial extent across the maps including CO and its isotopologues, high density tracers (e.g., HCN, HNC, CS, HCO^+^), and tracers of UV irradiation (e.g., CN and C_2_H). The spatially extended species reveal a complex velocity-structure of W49A with possible infall and outflow motions. Large variations are seen between the subregions with mostly blue-shifted emission toward the eastern tail, mostly red-shifted emission toward the northern clump, and emission peaking around the expected source velocity toward the southwest clump. A comparison of column density ratios of characteristic species observed toward W49A to Galactic PDRs suggests that while the chemistry toward the W49A center is driven by a combination of UV irradiation and shocks, UV irradiation dominates for the northern clump, eastern tail, and southwest clump regions. A comparison to a starburst galaxy and an active galactic nucleus suggests similar C_2_H, CN, and H_2_CO abundances (with respect to the dense gas tracer ^34^CS) between the ~0.8pc scale probed for W49A and the >1kpc regions in external galaxies with global star formation.
- ID:
- ivo://CDS.VizieR/J/A+A/216/44
- Title:
- Walraven photometry in Sco-Cen association
- Short Name:
- J/A+A/216/44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Walraven photometry is presented of established and probable members of the Scorpio-Centaurus OB association. For each star, effective temperature and surface gravity are derived using Kurucz atmosphere models (1979ApJS...40....1K). From the Straizys and Kuriliene (1981Ap&SS..80..353S) tables, absolute magnitudes are calculated. Distance moduli and visual extinctions are determined for all stars. From a comparison of the HR-diagrams of the stars in each subgroup with theoretical isochrones, the ages of the three subgroups are derived. The distances to the three subgroups are shown to be different; there is a general trend (also within each subgroup) for the distances to be larger at higher galactic longitudes. The visual extinction in the youngest subgroup Upper-Scorpius, is well correlated with the IRAS 100-micron map. The distance toward the Ophiuchus dark clouds is found to be 125 pc, based on the photometric distances to the stars. Most of the early-type stars in Upper-Scorpius are located at the far side of the dark clouds.
- ID:
- ivo://CDS.VizieR/J/A+AS/98/505
- Title:
- Walraven photometry near AG Car
- Short Name:
- J/A+AS/98/505
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Walraven-photometric data of 114 stars of 5.9<V<14.7 within 17 arcmin of the Luminous Blue Variable AG Car (HD 94910). The results are expressed in terms of V-magnitude in the Johnson system and in observed and extinction-free colours in the Walraven system. For a description of the Walraven photometric system, see e.g. <GCPD/11>
- ID:
- ivo://CDS.VizieR/J/A+AS/101/87
- Title:
- Walraven photometry of 8 Cataclysmic variables
- Short Name:
- J/A+AS/101/87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The files contain the results of the photometry observations obtained during July/August 1988 with the Walraven photometer on the 90cm telescope at ESO (La Silla). The brightness measurements are collected simultaneously in the 5 passbands VBLUW (544, 430, 384, 362 and 324nm) with integration times of 16s.
- ID:
- ivo://CDS.VizieR/J/A+AS/137/113
- Title:
- Walraven photometry of OB stars
- Short Name:
- J/A+AS/137/113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of OB-stars, made in 1959 and 1960 at the Leiden Southern Station near Hartebeespoortdam, South Africa, with the VBLUW photometer attached to th e 90 cm light-collector, are given in this paper. They are compared with photome try obtained by Graham (1968BANS....2..397G), Walraven & Walraven (1977BAN....15...67W), Lub & Pel (1977A&A....54..137L) and van Genderen et al. (1984A&AS...58..537V). Formulae for the transformation of the present observations to those of Walraven & Walraven (1977BAN....15...67W) and Lub & Pel (1977A&A....54..137L) are given. For a description of the VBLUW photometric system, see e.g. <GCPD/11>
- ID:
- ivo://CDS.VizieR/J/A+A/369/527
- Title:
- Walraven photometry of OB stars
- Short Name:
- J/A+A/369/527
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- About 700 stars, mostly OB-stars, were observed by the author at the former Leiden Southern Station at Hartebees poortdam, South Africa, in the observing seasons 1965, 1968, 1969, 1974, 1977, 1978. Observations were made in the five channels of the Walraven photometric system. Due to weathering of the telescope mirror the W channel gave no reliable results for the faintest stars (m=11mag); in these cases the U-W colour index is not given. The change in sensitivity in the V channel, supposedly having occurred in 1968, was not recognised. For a description of the Walraven VBLUW photometric system, see e.g. <GCPD/11>