- ID:
- ivo://CDS.VizieR/J/PASJ/59/1185
- Title:
- Water maser in galactic IRAS sources
- Short Name:
- J/PASJ/59/1185
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present H_2_O maser data from a survey toward IRAS sources in the Galaxy with the Nobeyama 45m telescope. This survey had a 1{sigma} noise level as small as 0.24Jy, resulting in one of the most sensitive water-maser surveys. The maximum distance of the masers to be detected by our survey is estimated to be 3kpc for sources with F_nu,1kpc_<10Jy and 10kpc for those with 10Jy<=F_nu,1kpc_<100Jy, where F_nu,1kpc_ is the maser flux density converted at a distance of 1kpc. For strong masers with F_nu,1kpc_>=100Jy, our survey could detect all sources in the Galaxy. We carried out a total of 2229 observations toward 1563 sources and detected water-maser emission toward 222 sources. Our survey newly found masers from 75 of the 222 sources.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/826/136
- Title:
- Water masers in M31. II. Multiwavelength data
- Short Name:
- J/ApJ/826/136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comparative multiwavelength analysis of water-maser-emitting regions and non-maser-emitting luminous 24{mu}m star-forming regions in the Andromeda Galaxy (M31) to identify the sites most likely to produce luminous water masers useful for astrometry and proper motion studies. Included in the analysis are Spitzer 24{mu}m photometry, Herschel 70 and 160{mu}m photometry, H{alpha} emission, dust temperature, and star-formation rate. We find significant differences between the maser-emitting and non-maser-emitting regions: water-maser-emitting regions tend to be more infrared-luminous and show higher star-formation rates. The five water masers in M31 are consistent with being analogs of water masers in Galactic star-forming regions and represent the high-luminosity tail of a larger (and as yet undetected) population. Most regions likely to produce water masers bright enough for proper motion measurements using current facilities have already been surveyed, but we suggest three ways to detect additional water masers in M31: (1) reobserve the most luminous mid- or far-infrared sources with higher sensitivity than was used in the Green Bank Telescope survey; (2) observe early-stage star-forming regions selected by millimeter continuum that have not already been selected by their 24{mu}m emission, and (3) reobserve the most luminous mid- or far-infrared sources and rely on maser variability for new detections.
- ID:
- ivo://CDS.VizieR/J/ApJ/826/24
- Title:
- Water masers in M31. I. Recombination lines
- Short Name:
- J/ApJ/826/24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of a Green Bank Telescope survey for water masers, ammonia (1,1) and (2,2), and the H66{alpha} recombination line toward 506 luminous compact 24{mu}m emitting regions in the Andromeda Galaxy (M31). We include the 206 sources observed in the Darling water maser survey for completeness. The survey was sensitive enough to detect any maser useful for ~10{mu}as/yr astrometry. No new water masers, ammonia lines, or H66{alpha} recombination lines were detected individually or in spectral stacks reaching rms noise levels of ~3mJy and ~0.2mJy, respectively, in 3.1-3.3km/s channels. The lack of detections in individual spectra and in the spectral stacks is consistent with Galactic extrapolations. Contrary to previous assertions, there do not seem to be any additional bright water masers to be found in M31. The strong variability of water masers may enable new maser detections in the future, but variability may also limit the astrometric utility of known (or future) masers because flaring masers must also fade.
1194. Water maser survey
- ID:
- ivo://CDS.VizieR/J/AJ/132/1322
- Title:
- Water maser survey
- Short Name:
- J/AJ/132/1322
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the most sensitive water maser survey toward Bok globules to date, performed using NASA's 70m antenna at Robledo de Chavela (Spain). We observed 207 positions within the Clemens and Barvainis catalog with a higher probability of harboring a young star, using as selection criteria the presence of radio continuum emission (from submillimeter to centimeter wavelengths), geometric centers of molecular outflows, peaks in maps of high-density gas tracers (NH3 or CS), and IRAS point sources. We have obtained seven maser detections, six of which (in CB 34, CB 54, CB 65, CB 101, CB 199, and CB 232) are reported for the first time here. Most of the water masers we detected are likely to be associated with young stellar objects (YSOs), except for CB 101 (probably an evolved object) and CB 65 (uncertain nature). The water maser in CB 199 shows a relatively high shift (30km/s) of its velocity centroid with respect to the cloud velocity, which is unusual for low-mass YSOs. We speculate that high-velocity masers in this kind of object could be related to episodes of energetic mass loss in close binaries. Alternatively, the maser in CB 199 could be pumped by a protoplanetary or a young planetary nebula. CB 232 is the smallest Bok globule (0.6pc) known to be associated with water maser emission, although it would be superseded by the cases of CB 65 (0.3pc) and CB 199 (0.5pc) if their association with YSOs is confirmed. All our selection criteria have statistically compatible detection rates, except for IRAS sources, which tend to be somewhat worse predictors for the presence of maser emission.
- ID:
- ivo://CDS.VizieR/J/ApJ/667/308
- Title:
- Weak-line T Tauri in Spitzer c2d Survey. II.
- Short Name:
- J/ApJ/667/308
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- One of the central goals of the Spitzer Legacy Project "From Cores to Disks" (c2d) is to determine the frequency of circumstellar disks around weak-line T Tauri stars (WTTSs) and to study the properties and evolutionary status of these disks. Here we present a census of disks for a sample of over 230 WTTSs located in the c2d IRAC and MIPS maps of the Ophiuchus, Lupus, and Perseus Molecular Clouds.
- ID:
- ivo://CDS.VizieR/J/ApJ/586/1356
- Title:
- White dwarfs with cool companions
- Short Name:
- J/ApJ/586/1356
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-infrared (IR) magnitudes for all white dwarfs (selected from the catalog of McCook & Sion, 1999, See Cat. <III/235>) contained in the Two Micron All-Sky Survey second incremental data release (2MASS 2IDR, Cat. <II/241>). We show that the near-IR color-color diagram is an effective means of identifying candidate binary stars containing a WD and a low-mass, main-sequence star. The loci of single WDs and WD+red dwarf binaries occupy distinct regions of the near-IR color-color diagram. We recovered all known unresolved WD+red dwarf binaries located in the 2IDR sky coverage and also identified as many new candidate binaries (47 new candidates out of 95 total). Using observational near-IR data for WDs and M-L dwarfs, we have compared a sample of simulated WD+red dwarf binaries with our 2MASS data. The colors of the simulated binaries are dominated by the low-mass companion through the late M to early L spectral types. As the spectral type of the companion becomes progressively later, however, the colors of unresolved binaries become progressively bluer. Binaries containing the lowest mass companions will be difficult to distinguish from single WDs solely on the basis of their near-IR colors.
- ID:
- ivo://CDS.VizieR/J/AJ/141/50
- Title:
- White-light flares on cool stars from Kepler
- Short Name:
- J/AJ/141/50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a search for white-light flares on ~23000 cool dwarfs in the Kepler Quarter 1 long cadence data. We have identified 373 flaring stars, some of which flare multiple times during the observation period. We calculate relative flare energies, flare rates, and durations and compare these with the quiescent photometric variability of our sample.
- ID:
- ivo://CDS.VizieR/J/A+A/563/A80
- Title:
- Wide field imagers ground-based astrometry. V.
- Short Name:
- J/A+A/563/A80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-precision astrometry requires accurate point-spread function modeling and accurate geometric-distortion corrections. This paper demonstrates that it is possible to achieve both requirements with data collected at the High Acuity Wide-field K-band Imager (HAWK-I); a wide-field imager installed at the Nasmyth focus of UT4/VLT ESO 8m telescope. Our final astrometric precision reaches ~3mas per coordinate for a well exposed star in a single image, with a systematic error less than 0.1mas. We constructed calibrated astro-photometric catalogs and atlases of 7 fields: the Baade's window, NGC 6656, NGC 6121, NGC 6822, NGC 6388, NGC 104, and the James Webb Space Telescope calibration field (in the LMC). We make these catalogs and images electronically available to the community. Furthermore, as a demonstration of the efficacy of our approach, combining archival material taken with the optical wide-field imager at the MPI/ESO 2.2m with HAWK-I observations, we are able to achieve an excellent separation between cluster members and field objects for NGC 6656 and NGC 6121 with a time base-line of about 8 years. Using both HST and HAWK-I data, we also study the radial distribution of the SGB populations in NGC 6656 and conclude that the radial trend is flat, within our uncertains. We also provide membership probabilities for most of the stars in NGC 6656 and NGC 6121 catalogs and estimate membership for the published variable stars in these two fields.
- ID:
- ivo://CDS.VizieR/J/ApJS/220/17
- Title:
- Wide-field NIR polarimetry of {rho} Oph cloud
- Short Name:
- J/ApJS/220/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We conducted wide and deep simultaneous JHK_s_-band imaging polarimetry of the {rho} Ophiuchi cloud complex. Aperture polarimetry in the JHK_s_ band was conducted for 2136 sources in all three bands, of which 322 sources have significant polarizations in all the JHK_s_ bands and have been used for a discussion of the core magnetic fields. There is a positive correlation between degrees of polarization and H-K_s_ color up to H-K_s_~3.5. The magnetic field structures in the core region are revealed up to at least A_V_~47mag and are unambiguously defined in each sub-region (core) of Oph-A, Oph-B, Oph-C, Oph-E, Oph-F, and Oph-AC. Their directions, degrees of polarization, and polarization efficiencies differ but their changes are gradual; thus, the magnetic fields appear to be connected from core to core, rather than as a simple overlap of the different cloud core components. Comparing our results with the large-scale field structures obtained from previous optical polarimetric studies, we suggest that the magnetic field structures in the core were distorted by the cluster formation in this region, which may have been induced by shock compression due to wind/radiation from the Scorpius-Centaurus association.
- ID:
- ivo://CDS.VizieR/J/A+A/633/A104
- Title:
- WINGS cluster galaxies structural parameters
- Short Name:
- J/A+A/633/A104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multi-wavelength analysis of the galaxies in nine clusters selected from the WINGS dataset, examining how galaxy structure varies as a function of wavelength and environment using the state of the art software galapagos-2. We simultaneously fit single-Sersic functions on three optical (u, B and V) and two near-infrared (J and K) bands thus creating a wavelength-dependent model of each galaxy. We measure the magnitudes, effective radius (Re), the Sersic index (n), axis ratio, and position angle in each band. The sample contains 790 cluster members (located close to the cluster centre <0.64xR200) and 254 non-member galaxies that we further separate based on their morphology into ellipticals, lenticulars, and spirals. We find that the Sersic index of all galaxies inside clusters remains nearly constant with wavelength while Re decreases as wavelength increases for all morphological types. We do not observe a significant variation on n and Re as a function of projected local density and distance from the clusters centre. Comparing the n and Re of bright cluster galaxies with a subsample of non-member galaxies we find that bright cluster galaxies are more concentrated (display high n values) and are more compact (low Re). Moreover, the light profile (N) and size (R) of bright cluster galaxies does not change as a function of wavelength in the same manner as non-member galaxies.
