- ID:
- ivo://CDS.VizieR/J/A+A/368/845
- Title:
- Arcetri Catalog of H2O maser sources. Update.
- Short Name:
- J/A+A/368/845
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a second update of the Arcetri Catalog of water masers (Comoretto et al., 1990A&AS...84..179C; Brand et al., 1994, Cat. <J/A+AS/103/541>). The present study reports the results of the observations carried out with the Medicina 32-m radiotelescope from January 1993 to April 2000 on a sample of 300 sources. This compilation consists of newly discovered maser sources that did not appear in the previous Arcetri Catalogs and is made of: a) detections from the literature, and b) unpublished detections obtained with the Medicina antenna. Overall, 83 out of 300 sources were detected. The detection rate is low (28%) and we attribute this result to the inclusion in our survey of a rather large number of spurious maser detections that have appeared in one particular paper. The observational parameters are reported in tabular form for all the 300 sources and the spectra of the detected masers are presented. We discuss the global properties of the complete Arcetri Catalog based on Comoretto et al. (1990A&AS...84..179C), Brand et al. (1994, Cat. <J/A+AS/103/541>) and the present observations, which now contains 1013 galactic water maser sources. Of these, 937 have an IRAS counterpart within 1 arcmin from the nominal position of the maser. We establish a classification scheme based on the IRAS flux densities which allows to distinguish between water masers associated with star forming regions and late-type stars. The Arcetri Catalog represents a useful data base for systematic studies of galactic water maser sources.
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- ID:
- ivo://CDS.VizieR/J/A+AS/103/541
- Title:
- Arcetri Catalogue of H2O Maser Sources
- Short Name:
- J/A+AS/103/541
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An update is presented of the Arcetri Atlas of water masers (Comoretto et al. 1990A&AS...84..179C). It contains the results of observations of water masers with the Medicina 32-m antenna. The observed sources were all discovered in the period 1989-1993, and were found either directly in the course of our own programs or were taken from the literature in which case they were re-observed at Medicina. We give the observed parameters of 214 sources in tabular form, and present all the spectra of the 141 detections.
- ID:
- ivo://CDS.VizieR/J/ApJ/656/255
- Title:
- Arecibo methanol maser Galactic Plane Survey
- Short Name:
- J/ApJ/656/255
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an unbiased survey for 6.7GHz methanol masers in the Galactic plane carried out using the 305m Arecibo radio telescope. A total of 18.2deg^2^ was surveyed with uniform sampling at 35.2<=l<=53.7, |b|<=0.41. The large collecting area of Aecibo and the sensitive C-Band High receiver allowed the survey to be complete at the level of 0.27Jy, making this the most sensitive blind survey carried out to date. We detected a total of 86 sources, 48 of which are new detections. Most of the new detections have a peak flux density below 2Jy. Many methanol masers are clustered, reflecting the formation of massive stars in clusters.
- ID:
- ivo://CDS.VizieR/J/ApJ/669/435
- Title:
- Arecibo Methanol Maser Galactic Plane Survey. II.
- Short Name:
- J/ApJ/669/435
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the properties of the 6.7GHz methanol maser sample detected in the Arecibo Methanol Maser Galactic Plane Survey. The distribution of the masers in the Galaxy, and statistics of their multiwavelength counterparts is consistent with the hypothesis of 6.7GHz maser emission being associated with massive young stellar objects. Using the detection statistics of our survey, we estimate the minimum number of methanol masers in the Galaxy to be 1275.
- ID:
- ivo://CDS.VizieR/J/A+A/481/169
- Title:
- ATCA 3mm obs. of NGC 6334I and NGC 6334I(N)
- Short Name:
- J/A+A/481/169
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the dense gas, the outflows, and the continuum emission from the massive twin cores NGC 6334I and I(N) at high spatial resolution. We imaged the region with the Australia Telescope Compact Array (ATCA) at 3.4mm wavelength in continuum, as well as CH_3_CN (5_K_-4_K_) and HCN(1-0) spectral line emission.
- ID:
- ivo://CDS.VizieR/J/ApJS/227/26
- Title:
- ATCA obs. of ground-state OH masers
- Short Name:
- J/ApJS/227/26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on high spatial resolution observations, using the Australia Telescope Compact Array (ATCA), of ground-state OH masers. These observations were carried out toward 196 pointing centers previously identified in the Southern Parkes Large-Area Survey in Hydroxyl (SPLASH) pilot region, between Galactic longitudes of 334{deg} and 344{deg} and Galactic latitudes of -2{deg} and +2{deg}. Supplementing our data with data from the MAGMO (Mapping the Galactic Magnetic field through OH masers) survey, we find maser emission toward 175 of the 196 target fields. We conclude that about half of the 21 nondetections were due to intrinsic variability. Due to the superior sensitivity of the followup ATCA observations, and the ability to resolve nearby sources into separate sites, we have identified 215 OH maser sites toward the 175 fields with detections. Among these 215 OH maser sites, 111 are new detections. After comparing the positions of these 215 maser sites to the literature, we identify 122 (57%) sites associated with evolved stars (one of which is a planetary nebula), 64 (30%) with star formation, two sites with supernova remnants, and 27 (13%) of unknown origin. The infrared colors of evolved star sites with symmetric maser profiles tend to be redder than those of evolved star sites with asymmetric maser profiles, which may indicate that symmetric sources are generally at an earlier evolutionary stage.
- ID:
- ivo://CDS.VizieR/J/A+AS/124/509
- Title:
- ATCA/VLA OH 1612 MHz survey. II.
- Short Name:
- J/A+AS/124/509
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations of the region between -45{deg}<=l<=-10{deg} and |b|<=3{deg} in the OH 1612.231MHz line, taken in 1994 January with the Australia Telescope Compact Array (ATCA). These observations are part of a larger survey, covering |l|<=45{deg} and |b|<=3{deg}, with the ATCA and the Very Large Array. In a previous article we have discussed the observational strategy in detail. In this paper we present only the objects found in this part of the survey. The region was systematically searched for OH-maser emission and was covered completely with 910 pointing centres separated by 30'. We found 202 OH-masing objects, 112 of which are new detections. Out of the 202 objects, 166 have a standard double-peaked spectral profile, 32 a single-peaked profile and 4 objects have non-standard or irregular profiles. In this article we analyse the data statistically and give classifications and identifications with known sources where possible. The astrophysical, kinematical, morphological and dynamical properties of subsets of the data will be addressed in future articles.
- ID:
- ivo://CDS.VizieR/J/A+A/366/481
- Title:
- ATCA/VLA OH 1612 MHz survey. III.
- Short Name:
- J/A+A/366/481
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations of the region between 5{deg}<=l<=45{deg} and |b|<=3{deg}, in the OH 1612.231MHz line, taken from 1993 to 1995 with NRAO's Very Large Array (VLA). These observations are the last part of a larger survey, covering |l|<=45{deg} and |b|<=3{deg}, with the Australia Telescope Compact Array (ATCA) and the VLA. The region was systematically observed on a 30'x30' grid in (l,b) and the resulting coverage was 92%, with 965 pointings. We found 286 OH-masing objects, 161 of which are new detections and 207 have reliable IRAS point-source identifications. The outflow velocity was determined for 276 sources. A total of 766 sources were detected in the combined ATCA/VLA survey, of which 29 were detected in two regions of the survey.
- ID:
- ivo://CDS.VizieR/J/MNRAS/431/1752
- Title:
- ATLASGAL 6.7GHz methanol masers
- Short Name:
- J/MNRAS/431/1752
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the 870um APEX Telescope large area survey of the Galaxy, we have identified 577 submillimetre continuum sources with masers from the methanol multibeam survey in the region 280{deg}<l<20{deg}; |b|<1.5{deg}. 94 per cent of methanol masers in the region are associated with submillimetre dust emission. We estimate masses for ~450 maser-associated sources and find that methanol masers are preferentially associated with massive clumps. These clumps are centrally condensed, with envelope structures that appear to be scale-free, the mean maser position being offset from the peak column density by 0+/-4 arcsec. Assuming a Kroupa initial mass function and a star formation efficiency of ~30 per cent, we find that over two-thirds of the clumps are likely to form clusters with masses >20M_{sun}_. Furthermore, almost all clumps satisfy the empirical mass-size criterion for massive star formation. Bolometric luminosities taken from the literature for ~100 clumps range between ~100 and 10^6^L_{sun}_. This confirms the link between methanol masers and massive young stars for 90 per cent of our sample. The Galactic distribution of sources suggests that the star formation efficiency is significantly reduced in the Galactic Centre region, compared to the rest of the survey area, where it is broadly constant, and shows a significant drop in the massive star formation rate density in the outer Galaxy.
- ID:
- ivo://CDS.VizieR/J/ApJ/822/59
- Title:
- BGPS. XIV. Molecular cloud clumps GBT obs.
- Short Name:
- J/ApJ/822/59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We sort 4683 molecular clouds between 10{deg}<l<65{deg} from the Bolocam Galactic Plane Survey based on observational diagnostics of star formation activity: compact 70{mu}m sources, mid-IR color-selected YSOs, H_2_O and CH_3_OH masers, and UCHII regions. We also present a combined NH_3_-derived gas kinetic temperature and H_2_O maser catalog for 1788 clumps from our own GBT 100m observations and from the literature. We identify a subsample of 2223 (47.5%) starless clump candidates (SCCs), the largest and most robust sample identified from a blind survey to date. Distributions of flux density, flux concentration, solid angle, kinetic temperature, column density, radius, and mass show strong (>1dex) progressions when sorted by star formation indicator. The median SCC is marginally subvirial ({alpha}~0.7) with >75% of clumps with known distance being gravitationally bound ({alpha}<2). These samples show a statistically significant increase in the median clump mass of {Delta}M~170-370M_{sun}_ from the starless candidates to clumps associated with protostars. This trend could be due to (i) mass growth of the clumps at dM/dt~200-440M_{sun}_/Myr for an average freefall 0.8Myr timescale, (ii) a systematic factor of two increase in dust opacity from starless to protostellar phases, and/or (iii) a variation in the ratio of starless to protostellar clump lifetime that scales as ~M^-0.4^. By comparing to the observed number of CH_3_OH maser containing clumps, we estimate the phase lifetime of massive (M>10^3^M_{sun}_) starless clumps to be 0.37+/-0.08Myr (M/10^3^M_{sun}_)^-1^; the majority (M<450M_{sun}_) have phase lifetimes longer than their average freefall time.
