- ID:
- ivo://CDS.VizieR/J/A+A/435/575
- Title:
- 86GHz SiO maser survey of late-type stars. III
- Short Name:
- J/A+A/435/575
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have determined extinction corrections for a sample of 441 late-type stars in the inner Galaxy, which we previously searched for SiO maser emission, using the 2MASS near-infrared photometry of the surrounding stars. From this, the near-infrared extinction law is found to be approximated by a power law A_lambda_{prop.to}lambda^-1.9+/-0.1^. Near- and mid-infrared colour-colour properties of known Mira stars are reviewed. From the distribution of the dereddened infrared colours of the SiO target stars we infer mass-loss rates between 10^-7^ and 10^-5^M_{sun}_/yr.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/619/A35
- Title:
- 86GHz SiO maser survey of late-type stars. IV
- Short Name:
- J/A+A/619/A35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an 86GHz SiO (v=1, J=2->1) maser search towards late-type stars located within |b|<0.5{deg} and 20{deg}<l<50{deg}. This search is an extension at longer longitudes of the work by Messineo et al. (2002, Cat. J/A+A/393/115). We selected 135 stars from the MSX catalog using color and flux criteria and detected 92 (86 new detections). The detection rate is 68%, the same as in our previous study. The last few decades have seen the publication of several catalogues of point sources detected in infrared surveys (MSX, 2MASS, DENIS, ISOGAL, WISE, GLIMPSE, AKARI, and MIPSGAL). We searched each catalogue for data on the 444 targets of our earlier survey and for the 135 in the survey reported here. We confirm that, as anticipated, most of our targets have colors typical of oxygen-rich AGB stars. Only one target star may have left the AGB already. Ten stars have colors typical of carbon-rich stars, meaning a contamination of our sample with carbon stars of <=1.7%.
- ID:
- ivo://CDS.VizieR/J/A+A/546/A16
- Title:
- 22-GHz water maser clouds
- Short Name:
- J/A+A/546/A16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Cool, evolved stars undergo copious mass loss but the detailed mechanisms and the form in which the matter is returned the ISM are still under debate. We investigated the structure and evolution of the wind at 5 to 50 stellar radii from Asymptotic Giant Branch and Red Supergiant stars.
- ID:
- ivo://CDS.VizieR/J/A+A/590/A131
- Title:
- Giant molecular filaments in the Milky Way
- Short Name:
- J/A+A/590/A131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Filamentary structures are common morphological features of the cold, molecular interstellar medium (ISM). Recent studies have discovered massive, hundred-parsec-scale filaments that may be connected to the large-scale, Galactic spiral arm structure. Addressing the nature of these giant molecular filaments (GMFs) requires a census of their occurrence and properties. We perform a systematic search of GMFs in the fourth Galactic quadrant and determine their basic physical properties. We perform a systematic search of GMFs in the fourth Galactic quadrant and determine their basic physical properties. Methods. We identify GMFs based on their dust extinction signatures in the near- and mid-infrared and the velocity structure probed by ^13^CO line emission. We use the ^13^CO line emission and ATLASGAL dust emission data to estimate the total and dense gas masses of the GMFs. We combine our sample with an earlier sample from literature and study the Galactic environment of the GMFs.
- ID:
- ivo://CDS.VizieR/J/A+A/563/A130
- Title:
- GLIMPSE/BGPS 6.7GHz methanol maser survey
- Short Name:
- J/A+A/563/A130
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a 6.7GHz methanol maser survey from the Effelsberg 100m radio telescope. A sample of 404 sources from the Bolocam Galactic Plane Survey (BGPS) 1.1mm dust clump survey that met specific Galactic Legacy Infrared Mid-Plane Survey Extraodinaire (GLIMPSE) point-source color criteria was selected and 318 of these were observed. The new observations resulted in the detection of 29 methanol masers, including 12 new ones. Together with the additional 74 detections from the literature, this means that a total of 103 methanol masers are coincident with 1.1mm dust clumps, yielding an overall detection rate of 26%. A comparison of the properties of a 1.1mm dust clump and a 6.7GHz methanol maser indicates that methanol masers with a higher flux density and/or luminosity are generally associated with more massive but less dense 1.1mm dust clumps. The overall detection rate of 26% appears to vary as a function of the derived H_2_ column density of the associated 1.1mm dust clump. The methanol masers were primarily detected toward the brighter and more massive 1.1mm dust clumps. A subsample of 194 sources that overlapped sources with observations of the 95GHz methanol line was investigated in more detail for the properties of 1.1mm dust clumps. The statistical analysis reveals that 1.1mm dust clumps with both class I and II counterparts have much higher mean and median values of mass, column density, and flux density than those with only class I or II counterparts. Based on our much larger sample, we slightly revise the boundary defined previously for selecting BGPS sources associated with a class II methanol maser, wherein ~80% of expected class II methanol masers will be detected with a detection rate in the range of 40-50%.
- ID:
- ivo://CDS.VizieR/J/MNRAS/377/571
- Title:
- GLIMPSE 6.7GHz methanol masers non-detections
- Short Name:
- J/MNRAS/377/571
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The University of Tasmania Mt Pleasant 26-m and Ceduna 30-m radio telescopes have been used to search for 6.7-GHz class II methanol masers towards 200 GLIMPSE (The Galactic Legacy Infrared Mid-Plane Survey Extraordinaire) sources. The target regions were selected on the basis of their mid-infrared colours as being likely to be young high-mass star formation regions and are either bright at 8.0{mu}m, or have extreme [3.6]-[4.5] colour. Methanol masers were detected towards 38 sites, nine of these being new detections. The prediction was that approximately 20 new 6.7-GHz methanol masers would be detected within 3.5-arcmin of the target GLIMPSE sources, but this is the case for only six of the new detections. A number of possible reasons for the discrepancy between the predicted and actual number of new detections have been investigated. It was not possible to draw any firm conclusions as to the cause, but it may be because many of the target sources are at an evolutionary phase prior to that associated with 6.7-GHz methanol masers. Through comparison of the spectra collected as part of this search with those in the literature, the average lifetime of individual 6.7-GHz methanol maser spectral features is estimated to be around 150yr, much longer than is observed for 22-GHz water masers.
- ID:
- ivo://CDS.VizieR/J/ApJS/209/25
- Title:
- H_2_O + CH_3_OH maser survey of Orion protostars
- Short Name:
- J/ApJS/209/25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of a maser survey toward 99 protostars in the Orion molecular cloud complex are presented. The target sources are low-mass protostars identified from infrared observations. Single-dish observations were carried out in the water maser line at 22GHz and the methanol class I maser lines at 44, 95, and 133GHz. Most of the detected sources were mapped to determine the source positions. Five water maser sources were detected, and they are excited by HH 1-2 VLA 3, HH 1-2 VLA 1, L1641N MM1/3, NGC 2071 IRS 1/3, and an object in the OMC 3 region. The water masers showed significant variability in intensity and velocity with time scales of 1 month or shorter. Four methanol emission sources were detected, and those in the OMC 2 FIR 3/4 and L1641N MM1/3 regions are probably masers. The methanol emission from the other two sources in the NGC 2071 IRS 1-3 and V380 Ori NE regions are probably thermal. For the water masers, the number of detections per protostar in the survey region is about 2%, which suggests that the water masers of low-mass protostars are rarely detectable. The methanol class I maser of low-mass protostars is an even rarer phenomenon, with a detection rate much smaller than 1%.
- ID:
- ivo://CDS.VizieR/J/ApJ/658/1096
- Title:
- H2O maser classification
- Short Name:
- J/ApJ/658/1096
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of 22GHz H2O maser observations of a sample of 85 post-asymptotic giant branch (post-AGB) candidate stars, selected on the basis of their OH 1612MHz maser and far-infrared properties. All sources were observed with the Tidbinbilla 70m radio telescope, and 21 detections were made; 86GHz SiO Mopra observations of a subset of the sample are also presented.
- ID:
- ivo://CDS.VizieR/J/ApJ/669/424
- Title:
- H2O maser emissions of IRAS 19134+2131
- Short Name:
- J/ApJ/669/424
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the Very Long Baseline Array at six epochs, we have observed H_2_O maser emission in the preplanetary nebula IRAS 19134+2131 (I19134), in which the H_2_O maser spectrum has two groups of emission features separated in radial velocity by ~100km/s. We also obtained optical images of I19134 with the Hubble Space Telescope to locate the bipolar reflection nebula in this source for the first time.
- ID:
- ivo://CDS.VizieR/J/MNRAS/430/1309
- Title:
- H_2_O masers in AFGL 2591 VLA 3-N
- Short Name:
- J/MNRAS/430/1309
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we analyse multi-epoch very long baseline interferometry water maser observations carried out with the Very Long Baseline Array towards the high-mass star-forming region AFGL 2591. We detected maser emission associated with the radio continuum sources VLA 2 and VLA 3. In addition, a water maser cluster, VLA 3-N, was detected ~0.5arcsec north of VLA 3. We concentrate the discussion of this paper on the spatio-kinematical distribution of the water masers towards VLA 3-N. The water maser emission towards the region VLA 3-N shows two bow-shock-like structures, northern and southern, separated from each other by ~100mas (~330AU). The spatial distribution and kinematics of the water masers in this cluster have persisted over a time span of 7yr. The northern bow shock has a somewhat irregular morphology, while the southern one has a remarkably smooth morphology. We measured the proper motions of 33 water maser features, which have an average proper motion velocity of ~1.3mas/yr (~20km/s). The morphology and the proper motions of this cluster of water masers show systematic expanding motions that could imply one or two different centres of star formation activity. We made a detailed model for the southern structure, proposing two different kinematic models to explain the three-dimensional spatio-kinematical distribution of the water masers: (1) a static central source driving the two bow-shock structures and (2) two independent driving sources, one of them exciting the northern bow-shock structure, and the other one, a young runaway star moving in the local molecular medium exciting and moulding the remarkably smoother southern bow-shock structure. Future observations will be necessary to discriminate between the two scenarios, in particular by identifying the still unseen driving source(s).
