- ID:
- ivo://CDS.VizieR/J/PASJ/64/4
- Title:
- SiO maser survey of nearby red variables
- Short Name:
- J/PASJ/64/4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to study the streaming motions of miras in the Solar neighborhood, we newly surveyed 379 red variables in the SiO maser lines at 42.821 and 43.122GHz with the Nobeyama 45m radio telescope. Accurate radial velocities were obtained for 229 (220 new) detected stars. The sample was selected from optical variables found by new automated surveys: the Northern Sky Variability Survey and the All Sky Automated Survey. The new sample consists of "bluer" objects compared with those observed in the previous SiO surveys. The distances to the objects were estimated using the period-luminosity relation, and they are mostly less than 3kpc from the Sun. The longitude-velocity diagram reveals three prominent groups of stars deviant from circular galactic rotation with a flat rotation curve. In addition to the Hercules group of stars, which was studied before, we found two new deviant groups: one toward the Perseus arm and the other toward the Sagittarius arm. These two groups both exhibit anomalous motions toward the galactic center, which seem to be consistent with the noncircular motions of these spiral arms found in recent VLBI proper-motion measurements for maser gas clumps.
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Search Results
- ID:
- ivo://CDS.VizieR/J/PASJ/55/203
- Title:
- SiO maser survey toward inner Galactic disk
- Short Name:
- J/PASJ/55/203
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an SiO maser survey for color-selected IRAS sources in the area 40{deg}<l<70{deg} and |b|<10{deg} in the SiO J=1-0, v=1 and 2 transitions (~43GHz). We detected 134 out of 272 observed sources in SiO masers; 127 were new detections. A systematic difference in the detection rates between SiO and OH maser searches was found.
- ID:
- ivo://CDS.VizieR/J/MNRAS/439/2584
- Title:
- Southern methanol masers at 36 and 44GHz
- Short Name:
- J/MNRAS/439/2584
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Australia Telescope Compact Array (ATCA) has been used for high angular resolution imaging of 71 southern class I methanol maser sources quasi-simultaneously at 36 and 44GHz. The data reveal a high level of morphological and kinematical complexity, and allow us to demonstrate associations, at arcsecond precision, of the class I maser emission with outflows, expanding HII regions, dark clouds, shocks traced by the 4.5-micron emission and 8.0-micron filaments. More than 700 maser component features were found at each of the two methanol transitions, but with only 23 per cent recognisable at both transitions; the morphology of class I emission is much better revealed by our survey of both transitions, compared with either one alone. We found that the number of masers falls exponentially with the projected linear distance from the associated class II 6.7-GHz methanol maser. This distribution has a scale of 263+/-15-milliparsec, irrespective of the transition. The class I masers associated with OH masers were found to have a tendency to be more spread out, both spatially and in the velocity domain. This is consistent with the expectation that such sources are more evolved. Apart from a small number of high-velocity components (which are largely blue-shifted and predominantly seen at 36GHz), the velocity distribution was found to be Gaussian, peaking near the systemic velocity of the region, which had been estimated as the middle of the velocity interval of the associated class II methanol maser at 6.7GHz. The mean indicated a small, but significant blue shift asymmetry of -0.57km/s (uncertainties are 0.06 and 0.07km/s for the 36- and 44-GHz masers, respectively) with respect to the 6.7GHz masers. The standard deviation of the velocity distribution was found to be 3.65+/-0.05 and 3.32+/-0.07km/s for the 36- and 44GHz masers, respectively. We also suggest a refined rest frequency value of 36169.238+/-0.011MHz for the 4_-1_-3_0_E methanol transition.
- ID:
- ivo://CDS.VizieR/J/AJ/132/2596
- Title:
- Spectroscopy of Ultraluminous IR galaxies
- Short Name:
- J/AJ/132/2596
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the types of nuclear environments that produce OH megamasers (OHMs) with a study of the optical spectra of 40 OHM host galaxies and a control sample of 30 non-masing (ultra)luminous infrared galaxies ([U]LIRGs). The optical spectrophotometry provides spatially resolved spectra of multiple nuclei in a few of these merging systems. Of the 40 OHMs classified, 33% are starbursts, 42% are LINERs, and 25% are Seyfert 2 galaxies; the classification of the non-masing control sample is similar.
- ID:
- ivo://CDS.VizieR/J/A+A/569/A125
- Title:
- Spiral structure of the Milky Way
- Short Name:
- J/A+A/569/A125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have updated the catalogs of Galactic HII regions, giant molecular clouds (GMCs), and 6.7-GHz methanol masers to outline the spiral structure of our Galaxy. The related parameters have been collected and (re)calculated based on the data in the literature. In particular, for each spiral tracer, we list the photometric or trigonometric distance, and/or the solutions of the kinematic distance ambiguity (KDA) when available. The kinematic distances when adopted are calculated using a flat rotation curve with two sets of R_0_, {Theta}_0_, and solar motions, where one set is the IAU standard and the other is from the new observational results. The rotation curve of Brand & Blitz (1993, Cat. J/A+A/275/67) is also used to derive the kinematic distances.
- ID:
- ivo://CDS.VizieR/J/other/RAA/18.146
- Title:
- Spiral structure of the Milky Way
- Short Name:
- J/other/RAA/18.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The morphology and kinematics of the spiral structure of the Milky Way are long-standing problems in astrophysics. In this review we firstly summarize various methods with different tracers used to solve this puzzle. The astrometry of Galactic sources is gradually alleviating this difficult situation caused mainly by large distance uncertainties, as we can currently obtain accurate parallaxes (a few {mu}as) and proper motions (~1km/s) by using Very Long Baseline Interferometry (VLBI). On the other hand, the Gaia mission is providing the largest, uniform sample of parallaxes for O-type stars in the entire Milky Way. Based upon the VLBI maser and Gaia O-star parallax measurements, nearby spiral structures of the Perseus, Local, Sagittarius and Scutum Arms are determined in unprecedented detail. Meanwhile, we estimate fundamental Galactic parameters of the distance to the Galactic center, R_0_, to be 8.35+/-0.18kpc, and circular rotation speed at the Sun, {THETA}_0_, to be 240+/-10km/s. We found kinematic differences between O stars and interstellar masers: the O stars, on average, rotate faster, >8km/s than maser-traced high-mass star forming regions.
- ID:
- ivo://CDS.VizieR/V/68A
- Title:
- Stellar Maser Observations
- Short Name:
- V/68A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains about 2958 stellar sources. For the searching of the maser emission of the sources listed, 368 were detected in H2O, 209 in SiO, and 713 in OH. In the catalog, one can find information about the stars including alternate names, the 1950 epoch position, velocity (LSR), spectral type, variability type, and period, as well as the references for both the detections and nondetections for each of the three molecules. In this catalog, Table 1 lists all the sources in right ascension order, Table 2 lists the references for all the maser observations for each source, and Table 3 lists the references in code order, i.e., in chronological order.
- ID:
- ivo://CDS.VizieR/J/ApJS/253/44
- Title:
- Survey of SiO maser emission in oxygen-rich stars
- Short Name:
- J/ApJS/253/44
- Date:
- 01 Mar 2022 00:16:35
- Publisher:
- CDS
- Description:
- Circumstellar environments of oxygen-rich stars are among the strongest SiO maser emitters. Physical processes such as collisions, infrared pumping, and overlaps favor the inversion of level population and produce maser emission at different vibrational states. Despite numerous observational and theoretical efforts, we still do not have a unified picture including all of the physical processes involved in SiO maser emission. The aim of this work is to provide homogeneous data in a large sample of oxygen-rich stars. We present a survey of 67 oxygen-rich stars from 7 to 1mm, in their rotational transitions from J=1-0 to J=5-4, for vibrational numbers v from 0 to 6 in the three main SiO isotopologs. We have used one of the 34 m NASA antennas at Robledo and the IRAM 30m radio telescope. The first tentative detection of a v=6 line is reported, as well as the detection of new maser lines. The highest vibrational levels seem confined to small volumes, presumably close to the stars. The J=1-0, v=2 line flux is greater than the corresponding v=1 in almost half of the sample, which may confirm a predicted dependence on the pulsation cycle. This database is potentially useful in models which should consider most of the physical agents, time dependency, and mass-loss rates. As a by-product, we report detections of 27 thermal rotational lines from other molecules, including isotopologs of SiS, H_2_S, SO, SO_2_, and NaCl.
- ID:
- ivo://CDS.VizieR/J/ApJS/244/25
- Title:
- The BAaDE SiO maser survey at 86GHz with ALMA
- Short Name:
- J/ApJS/244/25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the first 1432 sources observed using the Atacama Large Millimeter/submillimeter Array, from the Bulge Asymmetries and Dynamical Evolution survey, which aims to obtain tens of thousands of line-of-sight velocities from SiO masers in Asymptotic Giant Branch (AGB) stars in the Milky Way. A 71% detection rate of 86GHz SiO masers is obtained from the infrared color-selected sample and increases to 80% when considering the likely oxygen-rich stars using Midcourse Space Experiment colors isolated in a region where [D]-[E]<=1.38. Based on Galactic distributions, the presence of extended CS emission, and likely kinematic associations, the population of sources with [D]-[E]>1.38 probably consists of young stellar objects, or alternatively, of planetary nebulae. For the SiO detections, we examined whether individual SiO transitions provide comparable stellar line-of-sight velocities and found that any SiO transition is suitable for determining a stellar AGB line-of-sight velocity. Finally, we discuss the relative SiO detection rates and line strengths in the context of current pumping models.
- ID:
- ivo://CDS.VizieR/J/ApJ/727/20
- Title:
- The Megamaser Cosmology Project (MCP). III.
- Short Name:
- J/ApJ/727/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of H_2_O masers from circumnuclear disks in active galaxies for the Megamaser Cosmology Project (MCP) allow accurate measurement of the mass of supermassive black holes (BH) in these galaxies. We present the Very Long Baseline Interferometry images and kinematics of water maser emission in six active galaxies: NGC 1194, NGC 2273, NGC 2960 (Mrk 1419), NGC 4388, NGC 6264 and NGC 6323. We use the Keplerian rotation curves of these six megamaser galaxies, plus a seventh previously published, to determine accurate enclosed masses within the central ~0.3pc of these galaxies, smaller than the radius of the sphere of influence of the central mass in all cases.
