- ID:
- ivo://CDS.VizieR/J/ApJ/397/520
- Title:
- IRAS observations in Cr A
- Short Name:
- J/ApJ/397/520
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of IRAS data for a 57pc^2^ area of the nearby Corona Australis dark cloud complex. A total of 79 far-infrared sources are detected at 12{mu}m or in at least three IRAS bands. Combining these data with both newly obtained and previously published optical/infrared data, a total of 16 IRAS sources are identified with young stellar objects which are in close proximity to the R Coronae Australis cloud or Rossano Cloud B. Among these objects is a cold, heavily obscured young stellar object, IRAS 32, which radiates only in the 25-100{mu}m bands and is found to be associated with an extended near-infrared nebula. The majority of the remaining 63 IRAS sources in our sample appear to be related to field stars. A total of 24 young stellar objects are now known to be associated with the Cr A cloud and we investigate their collective properties through analysis of their spectral energy distributions. As observed for embedded populations in other dark clouds, the shapes of the spectral energy distributions constitute a nearly continuous sequence from cold, heavily obscured objects (extreme Class I) to T Tauri stars (Class II), with about equal numbers of Class I and Class II sources. There is a hint of a segregation of the shapes of the spectral energy distributions with source luminosity: eight of nine sources with L>1.8L_{sun}_ display Class I or flat energy distributions. We conclude that star formation in the Cr A cloud has proceeded in a manner similar to that in the rho Ophiuchi cloud in terms of duration and efficiency. We attribute the relatively low number of young stellar objects in Cr A to its lower mass of both low-density and high-density molecular gas. The luminosity function of the Cr A sources is unique only by the presence of six intermediate-luminosity (~100L_{sun}_) objects. Either the cloud has formed intermediate-mass stars more efficiently than lower mass objects relative to other dark clouds or several of these objects are interlopers.
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Search Results
- ID:
- ivo://CDS.VizieR/J/other/NewA/9.509
- Title:
- IRAS observations of Be stars
- Short Name:
- J/other/NewA/9.5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The IRAS associations for 193 Be stars are identified in this paper. From the infrared colors, the IRAS low-resolution spectra (LRS) and the spectral types, some physical properties and environment of the samples are discussed. It can be concluded that not only free-free emission or free-bound emission from the circumstellar ionized gas can be responsible for the large IR excesses of Be stars as suggested previously, but also, for some Be stars, thermal radiation from the circumstellar dust and/or nebula around the star can produce large IR excess as well. It is also found that the far IR excess of Be stars increases.
- ID:
- ivo://CDS.VizieR/VII/109
- Title:
- IRAS Observations of Large Optical Galaxies
- Short Name:
- VII/109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalogue reports the observations of 85 galaxies listed in RC2 with apparent blue light isophotal diameters (D25) greater than 8'; there are 83 corresponding maps (NGC 205 and M31 are in one field as are M81 and M82) listed in file "summary". The surface brightness maps have been written to tape in FITS format, as 83 sets of maps, each set consisting of an image and a noise map for each of the four IRAS wavelength bands, leading to 664 FITS images.
- ID:
- ivo://CDS.VizieR/J/A+AS/100/473
- Title:
- IRAS pointed observations data
- Short Name:
- J/A+AS/100/473
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have developed a system to process raw IRAS Pointed Observation (PO) data, using software developed at the Laboratory for Space Research, Groningen, The Netherlands. Several PO's can be coadded into one image. As an example we processed 99 PO's in the Chamaeleon I molecular cloud in to one image for every IRAS band. The list of extracted point sources contains some 300 new IRAS sources, down to a flux level of 21mJy at 12um.
- ID:
- ivo://irsa.ipac/IRAS/Catalog/PSC
- Title:
- IRAS Point Source Catalog
- Short Name:
- IRAS-PSC
- Date:
- 01 Oct 2018 20:27:21
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- This is a catalog of 245,889 well-confirmed point sources, i.e., sources with angular extents less than approximately 0.5', 0.5', 1.0', and 2.0' in the in-scan direction at 12, 25, 60, and 100 µm, respectively. Positions, flux densities, uncertainties, associations with known astronomical objects and various cautionary flags are given for each object. While two other complementary data sets - the Working Survey Database and the Point Source Reject Catalog - give information about point-like sources, the information available in the Point Source Catalog should satisfy almost all users. Away from confused regions of the sky, the survey is complete to about 0.4, 0.5, 0.6, and 1.0 Jy at 12, 25, 60, and 100 µm (cf. Faint Source Catalog). Typical position uncertainties are about 2" to 6" in-scan and about 8" to 16" cross-scan. The processing steps applied to detect and confirm point sources, and the positional and photometric error analyses are described in the Explanatory Supplement. The sources appear in order of increasing (1950.0) right ascension.
- ID:
- ivo://CDS.VizieR/III/170B
- Title:
- IRAS Point Source Identifications
- Short Name:
- III/170B
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The file "ps_class.dat" is an ASCII text file containing the classifications of 14,192 IRAS Point Sources with the flux at 12{mu}m greater than the flux at 25{mu}m and falling within about 7{deg} of the galactic plane. The aim has been to provide classifications of IRAS-PS with no previous associations, so most bright stars such as in the BSC, SAO, and HD which have associations and good spectral types are not included. Also, many known carbon stars from the catalogue of Stephenson known to be associated with PS are not included.
- ID:
- ivo://CDS.VizieR/II/274
- Title:
- IRAS Point Source Reject Catalog
- Short Name:
- II/274
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is a catalog of 372,774 potential infrared point sources that failed one or more of the confirmation and confusion criteria and were not, thus, included in the IRAS Point Source Catalog (Cat. II/125). These REJECTED sources include spurious objects (e.g., processing failures, space debris, asteroids and comets) and celestial sources that, due to incompleteness at faint levels or to variability, failed to achieve the minimum criterion of two hours-confirmed sightings. In regions of high source density the catalog includes sources rejected by the more severe criteria for reliability applied there. For detailed description about the IRAS mission and catalogues, see also http://lambda.gsfc.nasa.gov/product/iras/docs/exp.sup/toc.html
- ID:
- ivo://CDS.VizieR/J/A+A/631/A154
- Title:
- IRAS 15398-3359 polarization maps
- Short Name:
- J/A+A/631/A154
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Magnetic fields can significantly affect the star formation process. The theory of the magnetically driven collapse in a uniform field predicts that the contraction initially happens along the field lines. When the gravitational pull grows strong enough, the magnetic field lines pinch inwards, giving rise to a characteristic hourglass shape. We investigate the magnetic field structure of a young Class 0 object, IRAS 15398-3359, embedded in the Lupus I cloud. Previous observations at large scales have suggested that this source evolved in an highly magnetised environment. This object thus appears to be an ideal candidate to study the magnetically driven core collapse in the low-mass regime. We performed polarisation observations of IRAS 15398-3359 at 214um using the SOFIA telescope, thus tracing the linearly polarised thermal emission of cold dust. Our data unveil a significant bend of the magnetic field lines from the gravitational pull. The magnetic field appears ordered and aligned with the large-scale B-field of the cloud and with the outflow direction. We estimate a magnetic field strength of B=78uG, which is expected to be accurate within a factor of two. The measured mass-to-flux parameter is {lambda}=0.95, indicating that the core is in a transcritical regime.
- ID:
- ivo://CDS.VizieR/II/338
- Title:
- IRAS PSC/FSC Combined Catalogue
- Short Name:
- II/338
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Optical identifications of a few thousands of IRAS sources showed that IRAS Point Source and IRAS Faint Source catalogues (PSC and FSC, respectively) contain many quasars and active galactic nuclei, late-type stars, planetary nebulae, variables, etc. To increase the efficiency of using IRAS PSC and FSC, which contain a lot of common sources, one needs a joint catalogue of all IRAS point sources with improved data based on both catalogues. However, cross-correlation of the catalogues is not so easy, as the association of many sources is relative, and not always it is obvious, whose source from one catalogue corresponds to the other one in the second catalogue. This problem exists in case of using standard cross-correlation tools. Therefore, we have created a tool for cross-matching astronomical catalogues and we have applied it to IRAS PSC and FSC. Using this tool we have carried out identifications with a search radius corresponding to 3-{sigma} of errors for each source individually rather than a standard radius for all sources. As a result, we obtained 73,770 associations. In addition, we have made cross-correlations with AKARI-IRC, AKARI-FIS and WISE catalogues. We created a catalogue of 345,163 IRAS sources with high positional accuracy and with 17 photometric measurements from 1.25 to 160 ?m range, providing a detailed catalogue for IRAS point sources.
- ID:
- ivo://CDS.VizieR/J/ApJS/89/189
- Title:
- IRAS PSC new OH/IR stars. III.
- Short Name:
- J/ApJS/89/189
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of 1612MHz observations conducted at the Arecibo Observatory of 571 color-selected sources from the IRAS Point Source Catalog. Of these sources we detect 132, 113 for the first time. This is the third part of an Arecibo survey of color-selected IRAS sources. The earlier two parts together detected a total of 268 sources of 1612MHz emission. An analysis of the properties of the OH/IR stars detected in all three parts of the survey is included. In particular we compute the limiting 1612MHz peak flux of the entire survey to be ~40mJy. The correlation between the IRAS infrared fluxes and the 1612MHz flux of the 132 sources detected in part III of the survey is smaller than that found in the earlier parts of the survey. This is to be expected from the intrinsic variability of OH/IR stars and the longer time gap between the 1612MHz observations and the IRAS measurements. We identify a subset of 54 stars as being near the tangent point of the galactic rotation curve. Using the kinematical distances to these stars we find that the efficiency of momentum transfer varies exponentially with the (25-12){mu}m color, consistent with the stellar outflow being driven by radiation pressure. Further the IR pump efficiency increases with increasing optical depth of the circumstellar shell, as expected for radiative pumping. The bolometric luminosity function is found to decrease sharply above L_Bol_=5600L_{sun}_, and the 1612MHz luminosity function shows a corresponding falloff above L_1612_=1.8x10^-8^L_{sun}_. We also find direct confirmation of the expectation that sources with large expansion velocity are more luminous than sources with small expansion velocity.
