- ID:
- ivo://CDS.VizieR/J/ApJS/155/595
- Title:
- OH maser IRAS and MSX observations
- Short Name:
- J/ApJS/155/595
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present OH maser observations at 1612, 1665, 1667, and 1720MHz for 86 likely post-asymptotic giant branch (post-AGB) stars selected from a survey of 1612MHz maser sources in the Galactic plane. The observations were taken with the Parkes Telescope and the Australia Telescope Compact Array between 2002 September and 2003 August. We redetected all 86 sources at 1612MHz, while 27 sources were detected at 1665MHz and 45 at 1667MHz. One source was redetected at 1720MHz. We present a classification scheme for the maser profiles and show that 25% of sources in our sample are likely to have asymmetric or bipolar outflows.
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1162. OH masers in W3(OH)
- ID:
- ivo://CDS.VizieR/J/ApJ/668/331
- Title:
- OH masers in W3(OH)
- Short Name:
- J/ApJ/668/331
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent studies of methanol and ground-state OH masers at very high spectral resolution have shed new light on small-scale maser processes. The nearby source W3(OH), which contains numerous bright masers in several different transitions, provides an excellent laboratory for high spectral resolution techniques. We present a model of W3(OH) based on European VLBI Network (EVN) observations of the rotationally excited 6030 and 6035MHz OH masers taken at 0.024km/s spectral resolution.
- ID:
- ivo://CDS.VizieR/J/A+A/465/865
- Title:
- OH masers towards high mass protostellar object
- Short Name:
- J/A+A/465/865
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Masers are important tracers of the early evolution of young high mass stars, but the relationship between different types of maser and the evolutionary state of the exciting source remains unclear. ************************************************************************** * * * Sorry, but the author(s) never supplied the tabular material * * announced in the paper * * * **************************************************************************
- ID:
- ivo://CDS.VizieR/J/A+A/277/453
- Title:
- OH maser survey of cool IRAS sources
- Short Name:
- J/A+A/277/453
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The data are the results of a search for 1612MHz OH circumstellar masers in a colour limited sample of cool ORAS sources. Most of the observations were made at the Nancay radio telescope between January 1986 and February 1988; some were observed or reobserved later, between 1990 and 1992.
- ID:
- ivo://CDS.VizieR/J/AJ/124/100
- Title:
- OH megamasers at z>0.1. III
- Short Name:
- J/AJ/124/100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the final results from the Arecibo Observatory OH megamaser survey. We discuss in detail the properties of the remaining 18 OH megamasers detected in the survey, including three redetections. We place upper limits on the OH emission from 85 nondetections and examine the properties of 25 ambiguous cases for which the presence or absence of OH emission could not be determined. The complete survey has discovered 50 new OH megamasers (OHMs) in (ultra)luminous infrared galaxies ([U]LIRGs), which doubles the sample of known OHMs and increases the sample at z>0.1 sevenfold.
- ID:
- ivo://CDS.VizieR/J/AJ/133/496
- Title:
- OH megamasers infrared photometry
- Short Name:
- J/AJ/133/496
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- OH megamasers are the most luminous masers in the universe. The total of 109 OH megamaser (OHM) galaxies known so far have been collected, and cross-identifications of those OHM galaxies with Two Micron All Sky Survey (2MASS) sources are made in this paper. Using 2MASS (Cat. II/246) and IRAS (Cat. II/125, II/156) data, the infrared properties of OHM-detected and non-detected sources are compared.
- ID:
- ivo://CDS.VizieR/J/A+A/642/A145
- Title:
- OH 6035MHz line in high-mass SFRs
- Short Name:
- J/A+A/642/A145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The excited states of OH masers detected in the environment of high-mass young stellar objects (HMYSOs) are important for improving our understanding of the physical conditions of these objects and also provide information about their magnetic fields. We aim to search for excited-state OH 6035MHz maser emission in HMYSOs which might have escaped detection in previous surveys or were never searched for. Methods. A sample of HMYSOs derived from untargeted surveys of the 6668MHz methanol maser line was observed at 6035MHz OH transition with the Torun 32m radio telescope. The 6035MHz detections were observed in the OH 6031MHz line. Two-thirds of the detections were observed at least three times over a two-year period. Out of 445 targets, 37 were detected at 6035MHz, including seven new discoveries. The 6031MHz line was detected towards ten 6035MHz sources, one of which was not previously reported. All the newly detected sources are faint with the peak flux density lower than 4Jy and show significant or high variability on timescales of 4 to 20 months. Zeeman pair candidates identified in three new sources imply a magnetic field intensity of 2-11mG. Comparison of our spectra with those obtained ~10yr ago indicates different degrees of variability but there is a general increase in the variability index on an ~25yr timescale, usually accompanied by significant changes in the profile shape.
- ID:
- ivo://CDS.VizieR/J/ApJS/109/489
- Title:
- OH observations of Arecibo OH/IR stars
- Short Name:
- J/ApJS/109/489
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Arecibo 1612MHz survey of a complete sample of color-selected IRAS sources with 25{mu}m fluxes S(25)>2 Jy detected 393 OH/IR stars. A complementary 1667 and 1665MHz OH survey of these objects is presented here. Main-line masers have been detected in 238 surveyed objects: 18 exhibit only 1665MHz emission, 220 exhibit 1667MHz masers, and 119 exhibit both. The main lines were not detected in 159 objects.
- ID:
- ivo://CDS.VizieR/J/AJ/123/2772
- Title:
- OH-selected AGB and post-AGB objects. I.
- Short Name:
- J/AJ/123/2772
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using 766 compact objects found in a systematic survey of the Galactic plane in the 1612MHz masing OH line, new light is cast on the IR properties of evolved stars on the thermally pulsing asymptotic giant branch (AGB) and beyond. The usual mid-IR selection criteria for post-AGB, based on IRAS colors, largely fail to distinguish early post-AGB stages. A two-color diagram from much narrower band MSX flux densities, with bimodal distributions, provides a better tool for doing this. Four mutually consistent selection criteria for OH-masing red protoplanetary nebulae are given, as well as two for early post-AGB masers and one for all post-AGB masers including the earliest ones. All these criteria miss a group of blue, high-outflow post-AGB sources with 60{mu}m excess; these will be discussed in detail in Paper II (Sevenster, 2002AJ....123.2772S). The majority of post-AGB sources show regular double-peaked spectra in the OH 1612MHz line, with fairly low outflow velocities, although the fractions of single peaks and irregular spectra may vary with age and mass. The OH flux density shows a fairly regular relation with the stellar flux and the envelope optical depth, with the maser efficiency increasing with IRAS color R_21_. The OH flux density is linearly correlated with the 60{mu}m flux density.
- ID:
- ivo://CDS.VizieR/J/A+A/609/A16
- Title:
- OMC 1 reduced H_2_CO(3-2) datacubes
- Short Name:
- J/A+A/609/A16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We mapped the kinetic temperature structure of the Orion molecular cloud 1 (OMC-1) with para-H_2_CO(J_KaKc_=3_03_-2_02_, 3_22_-2_21_, and 3_21_-2_20_) using the APEX 12m telescope. This is compared with the temperatures derived from the ratio of the NH_3_ (2,2)/(1,1) inversion lines and the dust emission. Using the RADEX non-LTE model, we derive the gas kinetic temperature modeling the measured averaged line ratios of para-H_2_CO 3_22_-2_21_/3_03_-2_02_ and 3_21_-2_20_/3_03_-2_02_. The gas kinetic temperatures derived from the para-H_2_CO line ratios are warm, ranging from 30 to >200K with an average of 62+/-2K at a spatial density of 10^5^cm^-3^. These temperatures are higher than those obtained from NH_3_ (2,2)/(1,1) and CH_3_CCH(6-5) in the OMC-1 region. The gas kinetic temperatures derived from para-H_2_CO agree with those obtained from warm dust components measured in the mid infrared (MIR), which indicates that the para-H_2_CO(3-2) ratios trace dense and warm gas. The cold dust components measured in the far infrared (FIR) are consistent with those measured with NH_3_ (2,2)/(1,1) and the CH_3_CCH(6-5) line series. With dust at MIR wavelengths and para-H_2_CO(3-2) on one side and dust at FIR wavelengths, NH_3_ (2,2)/(1,1), and CH_3_CCH(6-5) on the other, dust and gas temperatures appear to be equivalent in the dense gas (n(H_2_)>~10^4^cm^-3^) of the OMC-1 region, but provide a bimodal distribution, one more directly related to star formation than the other. The non-thermal velocity dispersions of para-H2CO are positively correlated with the gas kinetic temperatures in regions of strong non-thermal motion (Mach number >~2.5) of the OMC-1, implying that the higher temperature traced by para-H2CO is related to turbulence on a ~0.06pc scale. Combining the temperature measurements with para-H_2_CO and NH3 (2,2)/(1,1) line ratios, we find direct evidence for the dense gas along the northern part of the OMC-1 10km/s filament heated by radiation from the central Orion nebula.
