- ID:
- ivo://CDS.VizieR/J/A+AS/129/363
- Title:
- IRAS flux densities of S stars
- Short Name:
- J/A+AS/129/363
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- It is the purpose of this paper to rediscuss the circumstellar properties of S stars and to put these properties in perspective with our current understanding of the evolutionary status of S stars, in particular the intrinsic/extrinsic dichotomy. This dichotomy states that only Tc-rich ("intrinsic") S stars are genuine thermally-pulsing asymptotic giant branch stars, possibly involved in the M-S-C evolutionary sequence. Tc-poor S stars are referred to as "extrinsic" S stars, because they are the cooler analogs of barium stars, and like them, owe their chemical peculiarities to mass transfer across their binary system. Accordingly, an extensive data set probing the circumstellar environment of S stars (IRAS flux densities, maser emission, CO rotational lines) has been collected and critically evaluated. This data set combines new observations (9 stars have been observed in the CO J=2-1 line and 3 in the CO J=3-2 line, with four new detections) with existing material (all CO and maser observations of S stars published in the literature). The IRAS flux densities of S stars have been re-evaluated by co-adding the individual scans, in order to better handle the intrinsic variability of these stars in the IRAS bands, and possible contamination by Galactic cirrus.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/276/57
- Title:
- IRAS Galactic star-forming regions. II.
- Short Name:
- J/MNRAS/276/57
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of the analysis of the occurrence of 22.2-GHz H_2_O maser emission in a sample of 1409 IRAS sources north of declination -30deg associated with star-forming regions are presented. Our sample contains all the IRAS sources that satisfy Emerson criteria for selecting molecular cores associated with the earliest evolutionary stages of the star-forming process. In a previous paper (Paper I, 1994MNRAS.266..123P), we have reported the results of the observations of about one third of the sample. In the present paper the observations of the remaining IRAS sources are presented: 18 of them are newly detected maser sources. The results show that 20 per cent of all IRAS sources that satisfy the Wood & Churchwell criteria have H2O water masers. This is in agreement with the assumption that these criteria select objects that are connected with the early phases of the evolution of high-mass star-forming regions. Moreover, about one third of the whole sample selected according to Emerson criteria contains IRAS sources that are not associated with massive star-forming processes, but probably with molecular cores in low-mass star-forming regions.
- ID:
- ivo://CDS.VizieR/J/PASJ/54/719
- Title:
- IRAS/SiO sources in the Galactic bulge
- Short Name:
- J/PASJ/54/719
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Near-infrared imaging observations of IRAS sources with SiO masers were made with the 2.3-m telescope of the Australian National University at Siding Spring Observatory, Australia, on 1997 June 18-23, 1998 June 9-12, and 2000 July 16-19, using the infrared array camera CASPIR. These infrared observations were made in parallel with long-term (1997-1999) SiO maser surveys at Nobeyama. The near-infrared observations were made within a year or so of the SiO detections. The details of the observations, data reduction, and method of identification were described in Deguchi et al. (1998PASJ...50..597D, 2001, Cat. <J/PASJ/53/293>), so they are not repeated here. All of the sources discussed in this paper are IRAS sources with detected SiO masers in the sky region of -10{deg}<l<15{deg} and |b|<3{deg} (Deguchi et al., 2000ApJS..130..351D).
- ID:
- ivo://CDS.VizieR/J/PASJ/53/293
- Title:
- IRAS/SiO sources toward Galactic Bulge
- Short Name:
- J/PASJ/53/293
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Near-infrared photometric observations in the J-, H-, and K-bands have been made for 86 IRAS sources toward the inner Galactic bulge (|l|<3{deg} and |b|<3{deg}). SiO maser emission has previously been detected in all of these sources; they are well-confirmed, mass-losing, late-type stars having accurate radial velocities derived from SiO observations. For 78 sources, single, unambiguous near-infrared counterparts were found within the errors of the IRAS positions; for the other 8 sources, multiple candidates, candidates with a low confidence level, or candidates overlapped with other stars were found. From the J-, H-, K-band and IRAS 12 and 25{mu}m intensities, we estimated the spectral energy distributions of the sources, and obtained the distances, assuming a constant luminosity. The derived distances of the IRAS/SiO sources are consistent with the current bar model of the Galactic bulge, where the near side of the bar is located in the first quadrant of the galactic longitude. We also reanalyzed the radial velocity shift with distance, and confirmed the presence of streaming motions of stars in the bar-like bulge.
- ID:
- ivo://CDS.VizieR/J/A+AS/98/589
- Title:
- IRAS Sources behind the Solar circle
- Short Name:
- J/A+AS/98/589
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/ApJ/628/789
- Title:
- IRAS03301+3057 water masers
- Short Name:
- J/ApJ/628/789
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work we present VLA observations of the NH3, CCS, and H2O maser emission at 1cm from the star-forming region B1-IRS (IRAS 03301+3057) with ~5" (=1750AU) of angular resolution. The CCS emission is distributed in three clumps around the central source. These clumps exhibit a velocity gradient from red- to blueshifted velocities toward B1-IRS, probably due to an interaction with the outflow from an embedded protostar.
- ID:
- ivo://CDS.VizieR/J/MNRAS/359/2
- Title:
- JHK photometry in G173.58+2.45
- Short Name:
- J/MNRAS/359/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multi-epoch infrared photometric study of the intermediate-mass star-forming region G173.58+2.45. Photometric observations are obtained using the near-infrared JHKL'M' filters and narrow-band filters centred at the wavelengths of the H_2_(1-0)S(1)(2.122um) and [FeII](1.644um) lines. The H2 image shows molecular emission from shocked gas, implying the presence of multiple star formation and associated outflow activity. We see evidence for several collimated outflows.
- ID:
- ivo://CDS.VizieR/J/other/PASA/26.439
- Title:
- K-band images of star-forming regions
- Short Name:
- J/other/PASA/26.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep, wide-field, Ks-band (2.14-micron) images towards 87 southern massive star formation regions traced by methanol maser emission. Using point-spread function fitting, we generate 2.14-micron point source catalogues (PSCs) towards each of the regions. For the regions between 10{deg}<l<350{deg} and |b|<1, we match the 2.14-micron sources with the GLIMPSE point source catalogue to generate a combined 2.14- to 8.0-micron point source catalogue. We provide this data for the astronomical community to utilise in studies of the stellar content of embedded clusters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/448/2344
- Title:
- MALT-45, a 7mm survey of the southern Galaxy
- Short Name:
- J/MNRAS/448/2344
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results from the MALT-45 (Millimetre Astronomer's Legacy Team-45GHz) Galactic Plane survey. We have observed 5 square degrees (l=330{deg}-335{deg}, b=+/-0.5{deg}) for spectral lines in the 7mm band (42-44 and 48-49GHz), including CS (1-0), class I CH_3_OH masers in the 7(0,7)-6(1,6) A^+^ transition and SiO (1-0) v=0,1,2,3. MALT-45 is the first unbiased, large-scale, sensitive spectral line survey in this frequency range. In this paper, we present data from the survey as well as a few intriguing results; rigorous analyses of these science cases are reserved for future publications. Across the survey region, we detected 77 class I CH_3_OH masers, of which 58 are new detections, along with many sites of thermal and maser SiO emission and thermal CS. We found that 35 class I CH_3_OH masers were associated with the published locations of class II CH_3_OH, H_2_O and OH masers but 42 have no known masers within 60 arcsec. We compared the MALT-45 CS with NH_3_ (1,1) to reveal regions of CS depletion and high opacity, as well as evolved star-forming regions with a high ratio of CS to NH_3_. All SiO masers are new detections, and appear to be associated with evolved stars from the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE). Generally, within SiO regions of multiple vibrational modes, the intensity decreases as v=1, 2, 3, but there are a few exceptions where v=2 is stronger than v=1.
- ID:
- ivo://CDS.VizieR/J/MNRAS/471/3915
- Title:
- MALT-45, 44 GHz class I methanol masers
- Short Name:
- J/MNRAS/471/3915
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We detail interferometric observations of 44GHz class I methanol masers detected by MALT-45 (a 7mm unbiased auto-correlated spectral-line Galactic-plane survey) using the Australia Telescope Compact Array. We detect 238 maser spots across 77 maser sites. Using high-resolution positions, we compare the class I CH_3_OH masers to other star formation maser species, including CS (1-0), SiO v=0 and the H53{alpha} radio-recombination line. Comparison between the cross- and auto-correlated data has allowed us to also identify quasi-thermal emission in the 44GHz class I methanol maser line. We find that the majority of class I methanol masers have small spatial and velocity ranges (<0.5pc and <5km/s), and closely trace the systemic velocities of associated clouds. Using 870{mu}m dust continuum emission from the ATLASGAL survey, we determine clump masses associated with class I masers, and find that they are generally associated with clumps between 1000 and 3000M_{sun}_. For each class I methanol maser site, we use the presence of OH masers and radio recombination lines to identify relatively evolved regions of high-mass star formation; we find that maser sites without these associations have lower luminosities and preferentially appear towards dark infrared regions.
