- ID:
- ivo://CDS.VizieR/J/AJ/105/427
- Title:
- IRAS fluxes of UCM galaxies
- Short Name:
- J/AJ/105/427
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of IRAS observations of the UCM (Universidad Complutense de Madrid) sample of emission-line galaxies, which have been selected from wide-dispersion H{alpha} objective-prism plates. These data are intended to provide a convenient summary of the relevant far-infrared (FIR) properties of these galaxies. Color-color diagrams, as interpreted by theoretical models, suggest that emission from UCM galaxies is mainly due to dust heated directly by photons emitted in active star-forming regions. Statistical analysis of some samples, including the IRAS minisurvey and blue selected objective-prism samples, have been performed. Comparisons, based on FIR luminosity distributions, with the IRAS minisurvey make evident the lower metallicity of the UCM galaxies which cannot be considered as a parent population of IRAS-detected galaxies. The FIR luminosity distributions of different samples have been compared using nonparametric methods and the best correlation has been found for the UCM and Wasilewski samples. Finally, a more detailed analysis of a UCM subsample has been performed from a three component model in order to get information concerning the fractional contribution of disk, star formation activity, and nonthermal mechanisms operating in the UCM galaxies.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/276/57
- Title:
- IRAS Galactic star-forming regions. II.
- Short Name:
- J/MNRAS/276/57
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of the analysis of the occurrence of 22.2-GHz H_2_O maser emission in a sample of 1409 IRAS sources north of declination -30deg associated with star-forming regions are presented. Our sample contains all the IRAS sources that satisfy Emerson criteria for selecting molecular cores associated with the earliest evolutionary stages of the star-forming process. In a previous paper (Paper I, 1994MNRAS.266..123P), we have reported the results of the observations of about one third of the sample. In the present paper the observations of the remaining IRAS sources are presented: 18 of them are newly detected maser sources. The results show that 20 per cent of all IRAS sources that satisfy the Wood & Churchwell criteria have H2O water masers. This is in agreement with the assumption that these criteria select objects that are connected with the early phases of the evolution of high-mass star-forming regions. Moreover, about one third of the whole sample selected according to Emerson criteria contains IRAS sources that are not associated with massive star-forming processes, but probably with molecular cores in low-mass star-forming regions.
- ID:
- ivo://CDS.VizieR/J/ApJS/95/457
- Title:
- IRAS images of nearby dark clouds
- Short Name:
- J/ApJS/95/457
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have investigated ~100 nearby molecular clouds using the extensive, all-sky database of IRAS. The clouds in this study cover a wide range of physical properties including visual extinction, size, mass, degree of isolation, homogeneity and morphology. IRAS 100 and 60 micrometre co-added images were used to calculate the 100 micrometre optical depth of dust in the clouds. These images of dust optical depth compare very well with ^12^CO and ^13^CO observations, and can be related to H_2_ column density. From the optical depth images we locate the edges of dark clouds and the dense cores inside them. We have identified a total of 43 "IRAS clouds" (regions with Av>2) which contain a total of 255 "IRAS cores" (regions with Av>4) and we catalog their physical properties. We find that the clouds are remarkably filamentary, and that the cores within the clouds are often distributed along the filaments. The largest cores are usually connected to other large cores by filaments. We have developed selection criteria to search the IRAS Point Source Catalog for stars that are likely to be associated with the clouds and we catalog the IRAS sources in each cloud or core. Optically visible stars associated with the clouds have been identified from the Herbig and Bell catalog. From these data we characterize the physical properties of the clouds including their star-formation efficiency.
- ID:
- ivo://CDS.VizieR/VII/185
- Title:
- IRAS 1.2 Jy IRAS Redshift Survey
- Short Name:
- VII/185
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is an explanation of the redshift survey of Fisher, Huchra, Strauss, Davis, Yahil and Schlegel; the data set is described in full in ApJ 361, 49 (1990). The data for the brighter half are included in ApJ Supp 1992, 83, 29; the data for the fainter half are included in a paper submitted for publication to the Astrophysical Journal Supplement. The survey contains 9897 objects selected from the IRAS database according to the criteria listed in that paper, briefly: F60 > 1.2 Jy; F60^2^ > F12 f25; |b| > 5; high source density flag at 60 microns not raised. Thus, the file consists of both galaxies and Galaxian contaminants; this is explained below. The sample contains ~5320 galaxies, and 14 objects without id's at the present time.
- ID:
- ivo://CDS.VizieR/J/ApJS/143/277
- Title:
- IRAS 1Jy sample of ultraluminous galaxies. I.
- Short Name:
- J/ApJS/143/277
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An imaging survey of the IRAS 1Jy sample of 118 ultraluminous infrared galaxies was conducted at optical (R) and near-infrared (K') wavelengths using the University of Hawaii 2.2 m telescope. The methods of observation and data reduction are described. An R and K' atlas of the entire sample is presented along with some of the basic astrometric and photometric parameters derived from these images. A more detailed analysis of these data is presented in a companion paper (Veilleux et al., 2002, Cat. <J/ApJS/143/315>).
- ID:
- ivo://CDS.VizieR/III/197
- Title:
- IRAS Low Resolution Spectra
- Short Name:
- III/197
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The IRAS survey instrumentation included a low-resolution spectrometer which covered the wavelength range between 8 and 22 um. The spectrometer operated during the entire survey, providing spectra of the brighter point sources. For details about the spectrometer, the reader is referred to the published book, chapter IX. The spectra included in file "lrs.dat" contain 200 points each, 100 points in the 8-13um range, and 100 points in the 11-22um range. There is therefore an overlapping between the longer wavelengths of the first sample and the shorter wavelengths of the second sample. The data points are stored as scaled integer arrays in the file "lrs.dat"; the corresponding values of the wavelengths are available in the file "calib.dat" . The file "lrs.dat" includes also data taken from the IRAS point source catalog <II/125>.
- ID:
- ivo://CDS.VizieR/J/A+A/468/1001
- Title:
- IRAS 20178+4046 maps at 610 and 1280MHz
- Short Name:
- J/A+A/468/1001
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multiwavelength study of the ultra compact HII region associated with IRAS 20178+4046. This enables us to probe the different components associated with this massive star forming region.
- 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.
