- ID:
- ivo://CDS.VizieR/J/MNRAS/367/1609
- Title:
- RCW 106 Giant Molecular Cloud 13CO mapping
- Short Name:
- J/MNRAS/367/1609
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first paper in a series detailing the results of ^13^CO observations of a ~1{deg}^2^ region of the giant molecular cloud (GMC) complex associated with the HII region RCW 106. The ^13^CO observations are also the first stage of a multi-molecular line study of the same region. These observations were amongst the first made using the new on-the-fly mapping capability of the Australia Telescope National Facility Mopra Telescope. In the configuration used, the instrument provided a full width at half-maximum (FWHM) beam size of 33arcsec and a velocity resolution of 0.17km/s. The gas emission takes the form of a string of knots, oriented along an axis that extends from the north-west (NW) to the south-east (SE) of the field of the observations, and which is surrounded by a more extended, diffuse emission. We analyse the 2D integrated ^13^CO emission using the CLUMPFIND algorithm and identify 61 clumps. We compare the gas data in the GMC with the dust data provided by 21um Midcourse Space Experiment (MSX) and 1.2mm Swedish European Southern Observatory Submillimetre Telescope (SEST) images that we both regridded to the cell spacing of the Mopra data and smoothed to the same resolution.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/870/115
- Title:
- Reddening, distance modulus & Fe/H of RRLs in w Cen
- Short Name:
- J/ApJ/870/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We developed a new approach to provide accurate estimates of the metal content, reddening, and true distance modulus of RR Lyrae stars (RRLs). The method is based on homogeneous optical (BVI) and near-infrared (JHK) mean magnitudes and on predicted period-luminosity-metallicity relations (IJHK) and absolute mean magnitude-metallicity relations (BV). We obtained solutions for three different RRL samples in {omega}Cen: first overtone (RRc, 90), fundamental (RRab, 80), and global (RRc+RRab) in which the period of first overtones were fundamentalized. The metallicity distribution shows a well defined peak at [Fe/H]~-1.98 and a standard deviation of {sigma}=0.54dex. The spread is, as expected, metal-poor ([Fe/H]<=-2.3) objects. The current metallicity distribution is ~0.3dex more metal-poor than similar estimates for RRLs available in the literature. The difference vanishes if the true distance modulus we estimated is offset by -0.06/-0.07mag in true distance modulus. We also found a cluster true distance modulus of {mu}=13.720{+/-}0.002{+/-}0.030mag, where the former error is the error on the mean and the latter is the standard deviation. Moreover, we found a cluster reddening of E(B-V)=0.132{+/-}0.002{+/-}0.028mag and spatial variations of the order of a few arcmin across the body of the cluster. Both the true distance modulus and the reddening are slightly larger than similar estimates available in the literature, but the difference is within 1{sigma}. The metallicity dependence of distance diagnostics agrees with theory and observations, but firm constraints require accurate and homogeneous spectroscopic measurements.
- ID:
- ivo://CDS.VizieR/J/MNRAS/410/1237
- Title:
- Red MSX survey (RMS) massive young stars
- Short Name:
- J/MNRAS/410/1237
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Red MSX Source (RMS) survey has identified a large sample of massive young stellar objects and ultra compact HII regions from a sample of ~2000 MSX and Two Micron All Sky Survey (2MASS) colour selected sources. Using a recent catalogue of molecular clouds derived from the Boston University-Five College Radio Astronomy Observatory (BU-FCRAO) Galactic Ring Survey (GRS), and by applying a Galactic scaleheight cut-off of 120pc, we solve the distance ambiguity for RMS sources located within 18{deg}<|l|>54{deg}. These two steps yield kinematic distances to 291 sources out of a possible 326, located within the GRS longitude range. Combining distances and integrated fluxes derived from spectral energy distributions, we estimate luminosities to these sources and find that >90 per cent are indicative of the presence of a massive star. We find the completeness limit of our sample is ~10^4^L_{sun}_, which corresponds to a zero-age main-sequence star with a mass of ~12M_{sun}_. Selecting only these sources, we construct a complete sample of 196 sources.
- ID:
- ivo://CDS.VizieR/J/MNRAS/418/1689
- Title:
- Red MSX water maser and ammonia emissions
- Short Name:
- J/MNRAS/418/1689
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Red MSX Source (RMS) survey has identified a sample of ~1200 massive young stellar objects (MYSOs), compact and ultra-compact HII regions from a sample of ~2000 MSX and Two Micron All Sky Survey (2MASS) colour-selected sources. We have used the 100-m Green Bank Telescope to search for 22-24GHz water maser and ammonia (1,1), (2,2) and (3,3) emission towards ~600 RMS sources located within the northern Galactic plane. We have identified 308 H_2_O masers which corresponds to an overall detection rate of ~50 per cent. We find no significant difference in the detection rate for HII regions and MYSOs which would suggest that the conditions required to produce maser emission are equally likely in both phases. Comparing the detection rates as a function of luminosity, we find the H_2_O detection rate has a positive dependence on the source luminosity, with the detection rate increasing with increasing luminosity.
- ID:
- ivo://CDS.VizieR/J/A+A/616/A175
- Title:
- Red supergiant stars in the LMC. II.
- Short Name:
- J/A+A/616/A175
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The characteristics of infrared properties and mid-infrared (MIR) variability of red supergiant (RSG) stars in the Large Magellanic Cloud (LMC) are analyzed based on 12 bands of near-infrared (NIR) to MIR co-added data from 2MASS, Spitzer and WISE, and ~6.6 years of MIR time-series data collected by the ALLWISE and NEOWISE-R projects. 773 RSGs candidates are compiled from the literature and verified by using the color-magnitude diagram (CMD), spectral energy distribution (SED) and MIR variability. About 15% of valid targets in the IRAC1-IRAC2/IRAC2-IRAC3 diagram may show Polycyclic Aromatic Hydrocarbon (PAH) emission. We show that arbitrary dereddening Q parameters related to the IRAC4, S9W, WISE3, WISE4 and MIPS24 bands could be constructed based on a precise measurement of MIR interstellar extinction law. Several peculiar outliers in our sample are discussed, in which one outlier might be a RSG right before the explosion or an extreme asymptotic giant branch (AGB) star in the very late evolutionary stage based on the MIR spectrum and photometry. There are 744 identified RSGs in the final sample having both the WISE1- and WISE2-band time-series data. The results show that the MIR variability is increasing along with the increasing of brightness. There is a relatively tight correlation between the MIR variability, mass loss rate (MLR; in terms of K_S-WISE3 color) and the warm dust/continuum (in terms of WISE4 magnitude/flux), where the MIR variability is evident for the targets with K_S-WISE3>1.0mag and WISE4<6.5mag, while the rest of the targets show much smaller MIR variability. The MIR variability is also correlated with the MLR for which targets with larger variability also show larger MLR with an approximate upper limit of -6.1M_{sun}_/yr. The variability and luminosity may both be important for the MLR since the WISE4-band flux is increasing exponentially along with the degeneracy of luminosity and variability. The identified RSG sample has been compared with the theoretical evolutionary models and shown that the discrepancy between observation and evolutionary models can be mitigated by considering both variability and extinction.
- ID:
- ivo://CDS.VizieR/J/A+A/577/A18
- Title:
- Reduced CRIRES spectra around S multiplet 3
- Short Name:
- J/A+A/577/A18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Sulphur is an important, volatile alpha element but its role in the Galactic chemical evolution is still uncertain. We derive the S abundances in RGB stars in three Galactic globular clusters (GC) that cover a wide metallicity range (-2.3<[Fe/H]<-1.2): M4, M22, and M30. The halo field stars show a large scatter in the [S/Fe] ratio in this metallicity span, which is inconsistent with canonical chemical evolution models. To date, very few measurements of [S/Fe] exist for stars in GCs, which are good tracers of the chemical enrichment of their environment. However, some light and alpha elements show star-to-star variations within individual GCs and it is yet unclear whether sulphur also varies between GC stars. We used the the infrared spectrograph CRIRES to obtain high-resolution (R~50000), high signal-to-noise (SNR~200 per px) spectra in the region of the SI multiplet 3 at 1045nm for 15 GC stars selected from the literature (6 stars in M4, 6 stars in M22 and 3 stars in M30). Multiplet 3 is better suited for S abundance derivation than the more commonly used lines of multiplet 1 at 920nm, since its lines are not blended by telluric absorption or other stellar features at low metallicity. We used spectral synthesis to derive the [S/Fe] ratio of the stars assuming local thermodynamic equilibrium (LTE). We find mean [S/Fe]=0.58+/-0.01+/-0.20dex (statistical and systematic error) for M4, [S/Fe]=0.57+/-0.01+/-0.19dex for M22, and [S/Fe]=0.55+/-0.02+/-0.16dex for M30. The negative NLTE corrections are estimated to be in the order of the systematic uncertainties. With the tentative exception of two stars with measured high S abundances, we conclude that sulphur behaves like a typical alpha element in the studied Galactic GCs, showing enhanced abundances with respect to the solar value at metallicities below [Fe/H]=-1.0dex without a considerable spread.
- ID:
- ivo://CDS.VizieR/J/A+A/629/A131
- Title:
- Reduced X-shooter spectra of GRB 190114A
- Short Name:
- J/A+A/629/A131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the detections of molecular hydrogen (H_2_), vibrationally-excited H_2_ (H_2_*), and neutral atomic carbon (CI), an efficient tracer of molecular gas, in two new afterglow spectra of GRBs 181020A (z=2.938) and 190114A (z=3.376), observed with X-shooter at the Very Large Telescope (VLT). Both host-galaxy absorption systems are characterized by strong damped Lyman-alpha absorbers (DLAs) and substantial amounts of molecular hydrogen with logN(HI,H_2_)=22.20+/-0.05, 20.40+/-0.04 (GRB 181020A) and logN(HI, H_2_)=22.15+/-0.05, 19.44+/-0.04 (GRB 190114A). The DLA metallicites, depletion levels, and dust extinctions are within the typical regimes probed by GRBs with [Zn/H]=-1.57+/-0.06, [Zn/Fe]=0.67+/-0.03, and AV=0.27+/-0.02mag (GRB 181020A) and [Zn/H]=-1.23+/-0.07, [Zn/Fe]=1.06+/-0.08, and AV=0.36+/-0.02mag (GRB 190114A). In addition, we examine the molecular gas content of all known H2-bearing GRB-DLAs and explore the physical conditions and characteristics required to simultaneously probe CI and H_2_*. We confirm that H2 is detected in all CI- and H2*-bearing GRB absorption systems, but that these rarer features are not necessarily detected in all GRB H2 absorbers. We find that a large molecular fraction of f_H2_>~10^-3^ is required for CI to be detected. The defining characteristic for H_2_* to be present is less clear, though a large H_2_ column density is an essential factor. We also find that the observed line profiles of the molecular-gas tracers are kinematically "cold", with small velocity offsets of {delta}v<20km/s from the bulk of the neutral absorbing gas. We then derive the H_2_ excitation temperatures of the molecular gas and find that they are relatively low with Tex~=100-300K, however, there could be evidence of warmer components populating the high-J H_2_ levels in GRBs 181020A and 190114A. Finally, we demonstrate that even though the X-shooter GRB afterglow campaign has been successful in recovering several H2-bearing GRB-host absorbers, this sample is still hampered by a significant dust bias excluding the most dust-obscured H_2_ absorbers from identification. CI and H_2_* could open a potential route to identify molecular gas even in low-metallicity or highly dust-obscured bursts, though they are only efficient tracers for the most H2-rich GRB-host absorption systems.
- ID:
- ivo://CDS.VizieR/J/ApJ/884/85
- Title:
- RELICS: Reionization Lensing Cluster Survey
- Short Name:
- J/ApJ/884/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Large surveys of galaxy clusters with the Hubble Space Telescope (HST) and Spitzer, including the Cluster Lensing And Supernova survey with Hubble and the Frontier Fields, have demonstrated the power of strong gravitational lensing to efficiently deliver large samples of high-redshift galaxies. We extend this strategy through a wider, shallower survey named RELICS, the Reionization Lensing Cluster Survey, described here. Our 188-orbit Hubble Treasury Program observed 41 clusters at 0.182<=z<=0.972 with Advanced Camera for Surveys (ACS) and WFC3/IR imaging spanning 0.4-1.7{mu}m. We selected 21 of the most massive clusters known based on Planck PSZ2 estimates and 20 additional clusters based on observed or inferred lensing strength. RELICS observed 46 WFC3/IR pointings (~200arcmin^2^) each with two orbits divided among four filters (F105W, F125W, F140W, and F160W) and ACS imaging as needed to achieve single-orbit depth in each of three filters (F435W, F606W, and F814W). As previously reported by Salmon+ (2020ApJ...889..189S), we discovered over 300 z~6-10 candidates, including the brightest z~6 candidates known, and the most distant spatially resolved lensed arc known at z~10. Spitzer IRAC imaging (945hr awarded, plus 100 archival, spanning 3.0-5.0{mu}m) has crucially enabled us to distinguish z~10 candidates from z~2 interlopers. For each cluster, two HST observing epochs were staggered by about a month, enabling us to discover 11 supernovae, including 3 lensed supernovae, which we followed up with 20 orbits from our program.
- ID:
- ivo://CDS.VizieR/III/237A
- Title:
- Revised Byurakan-IRAS stars (BIS) catalog
- Short Name:
- III/237A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Five lists of late-type stars were published in Astrophysics in 1997-2001, found in the First Byurakan Survey low-dispersion spectroscopic plates as optical identifications of unidentified IRAS sources. These identifications were carried out in the region with DE>+61 and |b|>15 with a surface of 1504deg^2^. As a result, the catalog of the Byurakan-IRAS Stars (BIS) was compiled. Its preliminary version was available at CDS since 2003, Cat. <III/237>. We have revised and updated the BIS catalog with the new data from recently published optical and infrared catalogs to give access to all available data and make possible further comparative studies of the properties of these objects. Cross-correlations of the BIS catalogue with the MAPS, USNO-B1.0 and 2MASS are made, updated SIMBAD data for the BIS objects are added, and accurate DSS1 and DSS2 positions and revised photometry are provided. The objects were checked for proper motion and variability as well. A refined classification from the Digitized First Byurakan Survey (DFBS) low-dispersion spectra was carried out. The revised and updated catalogue of 276 Byurakan-IRAS stars (BIS) is presented. The BIS catalogue can be used for a study of a complete sample of IRAS selected stars and for investigation of individual objects.
- ID:
- ivo://CDS.VizieR/III/266
- Title:
- Revised First Byurakan Survey of late-type stars
- Short Name:
- III/266
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Between 1990 and 2010, 15 lists of late-type stars found in the low-dispersion spectroscopic plates of the First Byurakan Survey (FBS) were published. The systematic search and selection was carried out on a surface of 16000 sq.deg. on almost the whole area of the FBS. As a result, a comprehensive catalogue of the late-type stars of the FBS was generated. Its preliminary version has been available at the CDS since 2007 (Cat. III/246). We have revised and updated the FBS catalogue of late-type stars with new data from recently published optical and multiwavelength catalogues to give access to all available data and to make further comparative studies of the properties of these objects possible. We have made cross-correlations with the Digitized First Byurakan Survey (DFBS, Cat. VI/116)), the United States Naval Observatory-B1.0 catalogue (Cat. I/284), the Guide Star Catalogue 2.3.2 (Cat. I/305), Tycho-2 (Cat. I/259), Sloan Digital Sky Survey Data Release 8 (Cat. II/306), the Two-Micron All-Sky Survey (2MASS, Cat. II/246)), the Wide-field Infrared Survey Explorer catalogue (WISE, Cat. II/311), the Infrared Astronomical Satellite Point Source Catalogue/Faint Source Catalogue (IRAS Catalogs II/125, II/156), the AKARI catalogue (Cat. II/297), the ROSAT Bright Source Catalogue (IX/10) and Faint Source (IX/29) Catalogues, the General Catalogue of Variable Stars (B/gcvs) and the Northern Sky Variability Survey. Also, we have added updated SIMBAD data for the objects. We present accurate Digitized Sky Survey 2 positions, approximate spectral subtypes refined from the DFBS low-dispersion spectra, luminosity classes estimated from 2MASS colours and available proper motions for 1045 FBS late-type stars. The FBS revised and updated catalogue lists a large number of completely new objects, which promise to extend very significantly the census of M giants, faint carbon stars at high Galactic latitudes and M dwarfs in the vicinity of the Sun. We study the complete samples, as well as investigating individual interesting objects up to 16.0-16.5mag in visual.
