Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/499/233
- Title:
- IRAS 05345+3157 mm high-angular resolution maps
- Short Name:
- J/A+A/499/233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To better understand the initial conditions of the high-mass star formation process, it is crucial to study at high-angular resolution the morphology, the kinematics, and eventually the interactions of the coldest condensations associated with intermediate-/high-mass star forming regions. The paper studies the cold condensations in the intermediate-/high-mass proto-cluster IRAS 05345+3157, focusing the attention on the interaction with the other objects in the cluster. We have performed millimeter high-angular resolution observations, both in the continuum and several molecular lines, with the PdBI and the SMA. The millimeter maps reveal the presence of 3 cores inside the interferometers primary beam, called C1-a, C1-b and C2. The lines, specifically N2H+ and N2D+, indicate the presence of two potential pre-stellar condensations (called N and S) not associated with the continuum sources. C1-b is very likely associated with a newly formed early-B ZAMS star embedded inside a hot-core, while C1-a is more likely associated with a class 0 intermediate-mass protostar. The nature of C2 is unclear. Both C1-a and C1-b are good candidates as driving sources of a powerful CO outflow, strongly interacting with both N and S, as demonstrated by the velocity gradient across both condensations. Our major conclusion is that the chemical properties of these pre-stellar cores are similar to those observed in low-mass isolated ones, while the kinematics is dominated by the turbulence triggered by the CO outflow, which can influence their evolution.
- ID:
- ivo://CDS.VizieR/J/A+A/594/A115
- Title:
- IRAS08589-4714 molecular gas
- Short Name:
- J/A+A/594/A115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the region IRAS 08589-4714 with the aim of characterizing the molecular environment. We observed the ^12^CO(3-2), ^13^CO(3-2), C^18^O(3-2), HCO^+^(3-2), and HCN(3-2) molecular lines in a region of 150"x150", centered on the IRAS source, to analyze the distribution and characteristics of the molecular gas linked to the IRAS source.
- 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.
- 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://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.