- 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.
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- ID:
- ivo://CDS.VizieR/J/A+A/365/545
- Title:
- Remnant disks around main-sequence stars IR flux
- Short Name:
- J/A+A/365/545
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometric ISO 60 and 170{mu}m measurements, complemented by some IRAS data at 60{mu}m, of a sample of 84 nearby main-sequence stars of spectral class A, F, G and K in order to determine the incidence of dust disks around such main-sequence stars. Fifty stars were detected at 60{mu}m; 36 of these emit a flux expected from their photosphere while 14 emit significantly more. The excess emission we attribute to a circumstellar disk like the ones around Vega and {beta} Pictoris. Thirty four stars were not detected at all; the expected photospheric flux, however, is so close to the detection limit that the stars cannot have an excess stronger than the photospheric flux density at 60{mu}m. Of the stars younger than 400Myr one in two has a disk; for the older stars this is true for only one in ten. We conclude that most stars arrive on the main sequence surrounded by a disk; this disk then decays in about 400Myr. Because (i) the dust particles disappear and must be replenished on a much shorter time scale and (ii) the collision of planetesimals is a good source of new dust, we suggest that the rapid decay of the disks is caused by the destruction and escape of planetesimals. We suggest that the dissipation of the disk is related to the heavy bombardment phase in our Solar System. Whether all stars arrive on the main sequence surrounded by a disk cannot be established: some very young stars do not have a disk. And not all stars destroy their disk in a similar way: some stars as old as the Sun still have significant disks.
- 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.
- ID:
- ivo://CDS.VizieR/II/326
- Title:
- Revised SWIRE photometric redshifts
- Short Name:
- II/326
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have revised the Spitzer Wide-Area Infrared Extragalactic survey (SWIRE) Photometric Redshift Catalogue to take account of new optical photometry in several of the SWIRE areas, and incorporating Two Micron All Sky Survey (2MASS) and UKIRT Infrared Deep Sky Survey (UKIDSS) near-infrared data. Aperture matching is an important issue for combining near-infrared and optical data, and we have explored a number of methods of doing this. The increased number of photometric bands available for the redshift solution results in improvements both in the rms error and, especially, in the outlier rate. We have also found that incorporating the dust torus emission into the quasi-stellar object (QSO) templates improves the performance for QSO redshift estimation. Our revised redshift catalogue contains over 1 million extragalactic objects, of which 26 288 are QSOs.
- ID:
- ivo://CDS.VizieR/J/ApJS/112/109
- Title:
- Rho Oph Near-IR Positions and Photometry
- Short Name:
- J/ApJS/112/109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains the tabulated results from a three-color (JHK) near-Infrared imaging survey of the Rho Ophiuchi star-forming cloud core. The NIR imaging observations were acquired using the SQIID instrument on the Kitt Peak 1.3m telescope from June 4-10, 1993 and April 23-28, 1994. The survey covered one square degree (2.2pc by 2.2pc). The catalog contains 4495 sources with both J2000.0 and B1950.0 coordinates for each source and its J, H, and K magnitudes and/or upper their limits. The Rho Ophiuchi clouds are of great interest for star formation studies, since they include the nearest example of a currently forming star cluster. The absolute positions in RA and Dec were determined for each individual source by using a centering algorithm in the IRAF package APPHOT to obtain center positions in pixels which were then merged into a single common positional grid. Absolute stellar coordinates were determined by comparing the authors positional database with the positions of 36 HST Guide Star Catalog stars spread out over the survey field. These were used to determine a plate scale and rotation which was used to generate the final list of source positions. The position determination technique and the photometric data reduction and calibration is discussed in detail in the source reference.
- ID:
- ivo://CDS.VizieR/J/MNRAS/401/1587
- Title:
- RIK photometry of far-IR sources in NGP
- Short Name:
- J/MNRAS/401/1587
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present follow-up observations of the far-infrared (FIR) sources at 90, 150 and 180um detected as part of the ISOPHOT EBL project, which has recently measured the absolute surface brightness of the cosmic infrared background (CIRB) radiation for the first time independently from COBE data. We have observed the fields at the North Galactic Pole region in the optical and near-IR, and complement these data with Sloan Digital Sky Survey photometry, and spectroscopy where available, and present identifications of the 25 FIR sources which reach down to ~150mJy in all three ISOPHOT bands. Identifications are done by means of full spectral energy density fitting to all sources in the FIR error circle areas.
908. RMS survey
- ID:
- ivo://CDS.VizieR/J/MNRAS/452/4029
- Title:
- RMS survey
- Short Name:
- J/MNRAS/452/4029
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of ammonia observations towards 66 massive star forming regions identified by the Red Midcourse Space Experiment Source survey. We have used the Green Bank Telescope and the K-Band Focal Plane Array to map the ammonia (NH_3_) (1,1) and (2,2) inversion emission at a resolution of 30 arcsec in 8 arcmin regions towards the positions of embedded massive star formation. We have identified a total of 115 distinct clumps, approximately two-thirds of which are associated with an embedded massive young stellar object or compact HII region, while the others are classified as quiescent. There is a strong spatial correlation between the peak NH3 emission and the presence of embedded objects. We derive the spatial distribution of the kinetic gas temperatures, line widths, and NH3 column densities from these maps, and by combining these data with dust emission maps we estimate clump masses, H_2_ column densities and ammonia abundances. The clumps have typical masses of ~1000M_{sun}_ and radii ~0.5pc, line widths of ~2km/s and kinetic temperatures of ~16-20K. We find no significant difference between the sizes and masses of the star-forming and quiescent subsamples; however, the distribution maps reveal the presence of temperature and line width gradients peaking towards the centre for the star-forming clumps while the quiescent clumps show relatively uniform temperatures and line widths throughout. Virial analysis suggests that the vast majority of clumps are gravitationally bound and are likely to be in a state of global free fall in the absence of strong magnetic fields. The similarities between the properties of the two subsamples suggest that the quiescent clumps are also likely to form massive stars in the future, and therefore provide an excellent opportunity to study the initial conditions of massive pre-stellar and protostellar clumps.
- ID:
- ivo://CDS.VizieR/J/A+A/501/539
- Title:
- RMS survey. 6cm observations of YSOs
- Short Name:
- J/A+A/501/539
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Red MSX Source (RMS) survey is an ongoing multi-wavelength observational programme designed to return a large, well-selected sample of massive young stellar objects (MYSOs). We have identified ~2000 MYSO candidates located throughout the Galaxy by comparing the colours of MSX and 2MASS point sources to those of known MYSOs. The aim of these follow-up observations is to identify other objects with similar colours such as ultra compact (UC) HII regions, evolved stars and planetary nebulae (PNe) and distinguish between genuine MYSOs and nearby low-mass YSOs. To identify the populations of UCHII regions and PNe within the sample and examine their Galactic distribution. We have conducted high resolution radio continuum observations at 6cm towards 659 MYSO candidates in the northern hemisphere (10{deg}<l<250{deg}) using the Very Large Array (VLA). These observations have a spatial resolution of ~1-2" and typical image rms noise values of ~0.22mJy - sensitive enough to detect a HII region powered by B0.5 star at the far side of the Galaxy. In addition to these targeted observations we present archival data towards a further 315 RMS sources extracted from a previous VLA survey of the inner Galaxy.
- ID:
- ivo://CDS.VizieR/J/MNRAS/430/1125
- Title:
- RMS survey: NIR spectroscopy of massive YSOs
- Short Name:
- J/MNRAS/430/1125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Near-infrared H- and K-band spectra are presented for 247 objects, selected from the Red MSX Source (RMS) survey as potential young stellar objects (YSOs). 195 (~80%) of the targets are YSOs, of which 131 are massive YSOs (L_BOL_>5x10^3^L_{sun}_, M>8M_{sun}_). This is the largest spectroscopic study of massive YSOs to date, providing a valuable resource for the study of massive star formation. In this paper, we present our exploratory analysis of the data. The YSOs observed have a wide range of embeddedness (2.7<A_V_<114), demonstrating that this study covers minimally obscured objects right through to very red, dusty sources. Almost all YSOs show some evidence for emission lines, though there is a wide variety of observed properties. The most commonly detected lines are Br{gamma}, H_2_, fluorescent FeII, CO bandhead, [FeII] and HeI 2-1 1S-1P, in order of frequency of occurrence. In total, ~40% of the YSOs display either fluorescent FeII 1.6878{mu}m or CO bandhead emission (or both), indicative of a circumstellar disc; however, no correlation of the strength of these lines with bolometric luminosity was found. We also find that ~60% of the sources exhibit [FeII] or H_2_ emission, indicating the presence of an outflow. Three quarters of all sources have Br{gamma} in emission. A good correlation with bolometric luminosity was observed for both the Br{gamma} and H_2_ emission line strengths, covering 1<L_BOL_<3.5x10^5^L_{sun}_. This suggests that the emission mechanism for these lines is the same for low-, intermediate- and high-mass YSOs, i.e. high-mass YSOs appear to resemble scaled-up versions of low-mass YSOs.