- 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.
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Search Results
- ID:
- ivo://CDS.VizieR/II/293
- Title:
- GLIMPSE Source Catalog (I + II + 3D)
- Short Name:
- II/293
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galactic Legacy Infrared Midplane Survey Extraordinaire (GLIMPSE), is a survey of Galactic Plane central parts made with the Infrared Array Camera (IRAC) aboard the Spitzer Space Telescope (SST). It covers approximately 220 square degrees, between galactic longitudes +/-65{deg} and +/-1{deg} in galactic latitude (up to 4.2{deg} in the central parts). The four IRAC bands are centered at approximately 3.6, 4.5, 5.8 and 8.0{mu}m. The GLIMPSE combines the 3 surveys: * GLIMPSE-I covers the longitude ranges |l|=10--65{deg} and the latitude range |b|<=1{deg} (Benjamin et al. 2003PASP..115..953B) * GLIMPSE-II covers the longitude range of |l|<=10{deg}, and a latitude range |b|<=1{deg} from |l|=5--10, |b|<=1.5 for |l|=2--5, and |b|<=2{deg} for |l|<=2. GLIMPSE-II coverage excludes the Galactic center region |l|<=1, |b|<=0.75 observed by the GALCEN GO program (PID=3677). * GLIMPSE-3D adds vertical extensions up to |b|=4.2{deg} near the galactic center, and up to |b|=3{deg} in selected other parts of the Galaxy (+/-10, 18.5, 25, 30, and -15 (345){deg}). GLIMPSE-II had two-epoch coverage for a total of three visits on the sky. The observations consisted of two 1.2 second integrations at each position in the first epoch of data taking (September 2005) and a single 1.2 second integration at each position six months later (April 2006). The highly reliable v2.0 GLIMPSEII Catalog (v2.0_GLMIIC) consists of point sources that are detected at least twice in one band and at least once in an adjacent band and a S/N > 5 cut for the band with the two detections. There are also faint and bright flux limits on the Catalog entries. The more complete v2.0 Archive (v2.0_GLMIIA) has less stringent criteria, namely two detections in any bands, those detections having a S/N > 5. The IRAC data were bandmerged with the 2MASS All-Sky Point Source Catalog. See the GLIMPSEII v2.0 Data Products & Data Delivery document for more details. The catalog available from CDS merges the 3 surveys GLIMPSE-I (v2.0), GLIMPSE-II (v2.0), and GLIMPSE-3D; Catalog and Archive records are also merged here. In the regions of overlap between the 3 surveys (e.g. longitude around 10{deg}) preference was given to (1) GLIMPSE-II, as recommended in the GLIMPSE documents of May 2007 (glimpse1_v2.0.pdf) and April 2008 (glimpse2-v2.0.pdf); (2) GLIMPSE-I, and (3) GLIMPSE-3D sources. Sources from different surveys were merged if their position is closer than 0.1arcsec. Documents and a document describing in detail the point source photometry steps, see http://www.astro.wisc.edu/glimpse/docs.html
- ID:
- ivo://CDS.VizieR/J/A+A/446/773
- Title:
- GLMP sample of galactic OH/IR stars
- Short Name:
- J/A+A/446/773
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical and near-infrared finding charts taken from the DSS and 2MASS surveys of 94 IRAS sources selected from the GLMP catalogue, and accurate astrometry (~0.2") for most of them. Selection criteria were very red IRAS colours representative for OH/IR stars with optically thick circumstellar shells and the presence of variability according to the IRAS variability index (VAR>50). The main photometric properties of the stars in this `GLMP sample' are presented, discussed and compared with the correspondent properties of the `Arecibo sample' of OH/IR stars studied nearlier. We find that 37% of the sample (N=34) has no counterpart in the 2MASS, implying extremely high optical depths of their shells. Most of the sources identified in the 2MASS are faint (K>~8) and are of very red colour in the near-infrared, as expected. The brightest 2MASS counterpart (K=5.3mag) was found for IRAS18299-1705. Its blue colour H-K=1.3 suggests that IRAS18299-1705 is a post-AGB star. Few GLMP sources have faint but relatively blue counterparts. They might be misidentified field stars or stars that recently experienced a drop of their mass loss rates. The `GLMP sample' in general is made of oxygen-rich AGB stars, which are highly obscured by their circumstellar shells. They belong to the same population as the reddest OH/IR stars in the `Arecibo sample'.
- ID:
- ivo://CDS.VizieR/J/ApJ/696/785
- Title:
- Global SFR density over 0.7<z<1.9
- Short Name:
- J/ApJ/696/785
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We determine the global star formation rate (SFR) density at 0.7<z<1.9 using emission-line-selected galaxies identified in Hubble Space Telescope-Near Infrared Camera and Multi-Object Spectrograph (HST-NICMOS) grism spectroscopy observations. Observing in a pure parallel mode throughout HST Cycles 12 and 13, our survey covers ~104arcmin^2^ from which we select 80 galaxies with likely redshifted H{alpha} emission lines. In several cases, a somewhat weaker [OIII] doublet emission is also detected.
- ID:
- ivo://CDS.VizieR/J/MNRAS/418/1994
- Title:
- GM 2-4 H_2_ emission-line objects
- Short Name:
- J/MNRAS/418/1994
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multi-wavelength study of the region towards the GM 2-4 nebula and the nearby source IRAS 05373+2340. Our near-infrared H_2_ 1-0 S(1) line observations reveal various shock-excited features which are part of several bipolar outflows. We identify candidates for the driving sources of the outflows from a comparison of the multi-waveband archival data sets and spectral energy distribution (SED) modelling. The SED spectral slope ({alpha}^IRAC^) for all the protostars in the field was then compared with the visual extinction map. This comparison suggests that star formation progresses from north-east to south-west across this region.
- ID:
- ivo://CDS.VizieR/J/A+A/655/A106
- Title:
- GO And, 84 UMa, kappa Psc ESPaDOnS spectra
- Short Name:
- J/A+A/655/A106
- Date:
- 11 Mar 2022 13:28:01
- Publisher:
- CDS
- Description:
- The aim of this work is to determine fundamental parameters of three Ap stars, GO And (HD 4778), {kappa} Psc (HD 220825), and 84 UMa (HD 120198), using spectroscopic techniques. By analysing these stars, we complete the sample of Ap stars for which fundamental parameters have additionally been derived by means of interferometry. This enables a cross-comparison of results derived by direct and indirect methods. Our study is based on the analysis of high-resolution spectra with a high signal-to-noise ratio that were obtained with ESPaDOnS spectrograph. We used an iterative method of fundamental parameter determinations that includes self-consistent modelling of the stellar atmosphere, taking individual abundances of chemical elements into account and subsequently fitting a theoretical spectral energy distribution to the observed distribution. The quality of the spectroscopic determinations was evaluated through a comparison with the interferometric results. For all investigated stars we determined fundamental parameters and derived chemical abundances that turn to be typical for Ap stars and are characterised mainly by gradual increase of heavy elements atmospheric abundance from an order of magnitude for iron peak elements up to very significant excesses of 3-4dex of the rare-earth elements relative to the solar values. The only exception is Ba which abundance is close to the solar one. There is also a significant He deficiency in the atmospheres of HD 120198 and HD 220825, whereas He abundance in HD 4778 is close to the solar one. We do not find significant Fe and Cr stratification. Using these abundances we constructed self-consistent atmospheric models for each star. The effect of the surface chemical inhomogeneity on the derived fundamental parameters did not exceed +/-100K in effective temperature which lies within a range of errors in similar self-consistent analyses of Ap stars. Finally, we compared spectroscopically derived effective temperatures, radii, and luminosity for 13 out of 14 Ap stars in benchmarking sample with the interferometric results. While radii and luminosity agree within the quoted errors of both determinations, spectroscopic effective temperatures are higher than the interferometric ones for stars with Teff>9000K. The observed hydrogen line profiles favour the spectroscopically derived temperatures.
- ID:
- ivo://CDS.VizieR/J/ApJ/865/73
- Title:
- GOBELINS. V. Kinematics of Perseus
- Short Name:
- J/ApJ/865/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive the distance and structure of the Perseus molecular cloud by combining trigonometric parallaxes from Very Long Baseline Array (VLBA) observations, taken as part of the GOBELINS survey and Gaia Data Release 2. Based on our VLBA astrometry, we obtain a distance of 321+/-10pc for IC 348. This is fully consistent with the mean distance of 320+/-26 measured by Gaia. The VLBA observations toward NGC 1333 are insufficient to claim a successful distance measurement to this cluster. Gaia parallaxes, on the other hand, yield a mean distance of 293+/-22pc. Hence, the distance along the line of sight between the eastern and western edges of the cloud is ~30pc, which is significantly smaller than previously inferred. We use Gaia proper motions and published radial velocities to derive the spatial velocities of a selected sample of stars. The average velocity vectors with respect to the LSR are (u,v,w)=(-6.1+/-1.6, 6.8+/-1.1, -0.9+/-1.2) and (-6.4+/-1.0, 2.1+/-1.4, -2.4+/-1.0)km/s for IC 348 and NGC 1333, respectively. Finally, our analysis of the kinematics of the stars has shown that there is no clear evidence of expansion, contraction, or rotational motions within the clusters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/371/1891
- Title:
- GOODS ELAIS-N1 24um flux densities
- Short Name:
- J/MNRAS/371/1891
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We address the question of how to deal with confusion-limited surveys in the mid-infrared (MIR) domain by using information from shorter-wavelength observations over the same sky regions. Such information, once applied to apparently extended MIR sources, which are indeed 'blends' of two or more different sources, allow us to disentangle the single counterparts and to split the measured flux density into different components. We present the application of this method to the 24-{mu}m Spitzer archival data in the Great Observatories Origins Deep Survey ELAIS-N1 (GOODS EN1) test field, where apparently extended, 'blended' sources constitute about 20 per cent of a reliable sample of 983 sources detected above the 5{sigma} threshold down to 40uJy. As a shorter-wavelength data set, we have considered the public Infrared Array Camera (IRAC) images and catalogues of the same field. We show that the 24-{mu}m sample is almost unbiased down to ~40uJy and the careful application of the deblending procedure does not require any statistical completeness correction (at least at the flux level considered). This is probed by direct comparison of our results with results in the literature that analysed the same data set through extensive Monte Carlo simulations. The extrapolation of the source counts down to fainter fluxes suggests that our 24-{mu}m sample is able to resolve ~62 per cent of the cosmic background down to a flux level of 38uJy.
- ID:
- ivo://CDS.VizieR/J/ApJ/790/49
- Title:
- Gould's Belt VLA survey. III. Orion region
- Short Name:
- J/ApJ/790/49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a high-sensitivity (60{mu}Jy), large-scale (2.26deg^2^) survey obtained with the Karl G. Jansky Very Large Array as part of the Gould's Belt Survey program. We detected 374 and 354 sources at 4.5 and 7.5GHz, respectively. Of these, 148 are associated with previously known young stellar objects (YSOs). Another 86 sources previously unclassified at either optical or infrared wavelengths exhibit radio properties that are consistent with those of young stars. The overall properties of our sources at radio wavelengths such as their variability and radio to X-ray luminosity relation are consistent with previous results from the Gould's Belt Survey. Our detections provide target lists for follow-up Very Long Baseline Array radio observations to determine their distances as YSOs are located in regions of high nebulosity and extinction, making it difficult to measure optical parallaxes.
- ID:
- ivo://CDS.VizieR/J/ApJ/805/9
- Title:
- Gould's Belt VLA Survey. II. Serpens region
- Short Name:
- J/ApJ/805/9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep (~17{mu}Jy) radio continuum observations of the Serpens molecular cloud, the Serpens south cluster, and the W40 region obtained using the Very Large Array in its A configuration. We detect a total of 146 sources, 29 of which are young stellar objects (YSOs), 2 of which are BV stars, and 5 more of which are associated with phenomena related to YSOs. Based on their radio variability and spectral index, we propose that about 16 of the remaining 110 unclassified sources are also YSOs. For approximately 65% of the known YSOs detected here as radio sources, the emission is most likely non-thermal and related to stellar coronal activity. As also recently observed in Ophiuchus, our sample of YSOs with X-ray counterparts lies below the fiducial Guedel & Benz (1993ApJ...405L..63G) relation. Finally, we analyze the proper motions of nine sources in the W40 region. This allows us to better constrain the membership of the radio sources in the region.
