- ID:
- ivo://CDS.VizieR/J/A+AS/80/149
- Title:
- IRAS Sources behind the Solar circle
- Short Name:
- J/A+AS/80/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CO (J=1->0) has been observed with the 15-m SEST and the 30-m IRAM telescope in the direction of 1302 IRAS sources with colors of star forming regions located within 10 deg of the galactic plane in the interval between 85 and 280 deg. Emission components with line profiles that are non-Gaussian (showing, e.g., possible self-absorption or wings) are identified; this information may serve as a basis for selecting sources for future research. For all components, kinematic heliocentric and galactocentric distances, and distances from the galactic plane are derived. For those components which may be associated with the IRAS sources, bolometric luminosities are derived. These data will be analyzed and compared with HI data in subsequent papers.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+AS/98/589
- Title:
- IRAS Sources behind the Solar circle
- Short Name:
- J/A+AS/98/589
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/A+A/626/A93
- Title:
- IRAS 16293-2422 spectral cubes
- Short Name:
- J/A+A/626/A93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The majority of stars form in binary or higher order systems. The Class 0 protostellar system IRAS16293-2422 contains two protostars, 'A' and 'B', separated by ~600au and embedded in a single, 10^4 au scale envelope. Their relative evolutionary stages have been debated. We aim to study the relation and interplay between the two protostars A and B at spatial scales of 60 to ~1000au. We selected molecular gas line transitions of CO, H_2_CO, HCN, CS, SiO, and CCH from the ALMA-PILS spectral imaging survey (329-363GHz) and used them as tracers of kinematics, density, and temperature in the IRAS16293-2422 system. The angular resolution of the PILS data set allows us to study these quantities at a resolution of 0.5 arcsec (60 au at the distance of the source). Line-of-sight velocity maps of both optically thick and optically thin molecular lines reveal: (i) new manifestations of previously known outflows emanating from protostar A; (ii) a kinematically quiescent bridge of dust and gas spanning between the two protostars, with an inferred density between 4x10^4^ and 3x10^7^cm^-3^; and (iii) a separate, straight filament seemingly connected to protostar B seen only in CCH, with a flat kinematic signature. Signs of various outflows, all emanating from source A, are evidence of high-density and warmer gas; none of them coincide spatially and kinematically with the bridge. We hypothesize that the bridge arc is a remnant of filamentary substructure in the protostellar envelope material from which protostellar sources A and B have formed. One particular morphological structure appears to be due to outflowing gas impacting the quiescent bridge material. The continuing lack of clear outflow signatures unambiguously associated to protostar B and the vertically extended shape derived for its disk-like structure lead us to conclude that source B may be in an earlier evolutionary stage than source A.
- ID:
- ivo://CDS.VizieR/J/A+A/633/A7
- Title:
- IRAS 16293-2422 spectral cubes
- Short Name:
- J/A+A/633/A7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Temperature is a crucial parameter in circumstellar disk evolution and planet formation because it governs the resistance of the gas to gravitational instability and sets the chemical composition of the planet-forming material. We set out to determine the gas temperature of the young disk-like structure around the Class 0 protostar IRAS 16293-2422A. We used Atacama Large Millimeter/submillimeter Array (ALMA) observations of multiple H_2_CS J=7-6 and J=10-9 lines from the Protostellar Interferometric Line Survey (PILS) to create a temperature map for the inner ~200AU of the disk-like structure. This molecule is a particularly useful temperature probe because transitions between energy levels with different K_a quantum numbers operate only through collisions. Based on the H_2_CS line ratios, the temperature is between ~100-175K in the inner ~150AU, and drops to ~75K at ~200AU. At the current resolution (0.5"~70AU), no jump is seen in the temperature at the disk-envelope interface. The temperature structure derived from H_2_CS is consistent with envelope temperature profiles that constrain the temperature from 1000AU scales down to ~100AU, but does not follow the temperature rise seen in these profiles at smaller radii. Higher angular resolution observations of optically thin temperature tracers are needed to establish whether cooling by gas-phase water, the presence of a putative disk, or the dust optical depth influences the gas temperature at <~100AU scales. The temperature at 100AU is higher in IRAS 16293A than in the embedded Class 0/I disk L1527, consistent with the higher luminosity of the former.
- ID:
- ivo://CDS.VizieR/J/MNRAS/421/679
- Title:
- IRAS 22023+5249 spectroscopy
- Short Name:
- J/MNRAS/421/679
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The first high-resolution (R~50000) optical spectrum of the B-type star, LS III +52 24, identified as the optical counterpart of the hot post-asymptotic giant branch (post-AGB) candidate IRAS 22023+5249 (I22023) is presented. We report the detailed identifications of the observed absorption and emission features in the full wavelength range (4290-9015{AA}) as well as the atmospheric parameters and photospheric abundances (under the local thermodynamic equilibrium approximation) for the first time. The nebular parameters (Te, Ne) are also derived.
- ID:
- ivo://CDS.VizieR/J/A+A/585/A112
- Title:
- IRAS 16293-2422 spectrum
- Short Name:
- J/A+A/585/A112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A fraction of the missing sulfur in dense clouds and circumstellar regions could be in the form of three species not yet detected in the interstellar medium: H_2_S_2_, HS_2_, and S_2_ according to experimental simulations performed under astrophysically relevant conditions. These S-S bonded molecules can be formed by the energetic processing of H_2_S-bearing ice mantles on dust grains, and subsequently desorb to the gas phase. The detection of these species could partially solve the sulfur depletion problem, and would help to improve our knowledge of the poorly known chemistry of sulfur in the interstellar medium. To this purpose we calculated the frequencies and expected intensities of the rotational transitions not previously reported, and performed dedicated ground-based observations toward the low-mass warm core IRAS 16293-2422, a region with one of the highest measured gas-phase H_2_S abundances. Observations in the submillimeter regime were obtained with the APEX 12m telescope during 15h of observation. A total of ~16GHz were covered in a range of about 100GHz, targeting a wide selection of the predicted rotational transitions of the three molecules.
- ID:
- ivo://CDS.VizieR/J/A+A/622/A38
- Title:
- IRAS05168+3634 star-forming region stellar content
- Short Name:
- J/A+A/622/A38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Aims. We report the investigation results of the structure and content of a molecular cloud surrounding the source IRAS 05168+3634 (also known as Mol 9). Methods. We present a photometric analysis using the data of J, H, K UKIDSS, [3.6], [4.5]{mu}m Spitzer-IRAC and 3.4, 4.6, 12, 22{mu}m WISE databases. A multi-color criteria was used to identify the candidates of young stellar objects (YSOs) in the molecular cloud; in addition to IRAS 05168+3634, there are four IRAS sources embedded in the same molecular cloud. Color-magnitude diagrams and the K luminosity function (KLF) were used to determine the basic parameters of stellar objects (spectral classes, masses, ages). To study the YSOs with longer wavelength photometry the radiative transfer models were used. Results. Based on color-color and color-magnitude diagrams, we identified a rich population of embedded YSO candidates with infrared excess (Class 0/I and Class II) and their characteristics in a quite large molecular cloud located in a region of 24 arcmin radius. The molecular cloud includes 240 candidates of YSOs within the radii of subregions around five IRAS sources. The local distribution of identified YSOs in the molecular cloud frequently shows elongation and subclustering. The observed young subregions and parental molecular cloud morphologies are similar, especially when only the youngest Class I/0 sources are considered. The color-magnitude diagrams of the subregions suggest a very young stellar population. We construct the KLF of the subregions except for the IRAS 05162+3639 region and it shows unusually low values for {alpha} slope: 0.12-0.21. According to the values of the slopes of the KLFs, the age of the subregions can be estimated at 0.1-3Myr. The spectral energy distributions (SEDs) are constructed for 45 Class I and 75 Class II evolutionary stage YSOs and the received parameters of these YSOs are well correlated with the results obtained by other methods. According to the results of SED fitting tool, the sources IRAS 05184+3635, IRAS 05177+3636, and IRAS 05162+3639 can be classified as Class I evolutionary stage objects. IRAS 05168+3634 and IRAS 05156+3643 can be classified as flat-spectrum objects.
- ID:
- ivo://CDS.VizieR/J/A+A/475/925
- Title:
- IRAS 05358+3543 (sub)mm maps
- Short Name:
- J/A+A/475/925
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the small-scale structure of massive star-forming regions through interferometric observations in several (sub)mm wavelength bands. We determine the kinetic temperature of the gas around the protostars, and derive the column density of several molecular species. For two of the protostars, constrains on the density are also inferred.
- ID:
- ivo://CDS.VizieR/J/other/BSAO/50.115
- Title:
- IRAS-TEXAS cross-identifications
- Short Name:
- J/other/BSAO/50.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A procedure of sampling objects by way of cross-identification of the low-frequency radio catalogue of objects obtained with the aid of the Texas interferometer at the frequency 365MHz and of the IRAS (Cat. <II/125>) catalogue is discussed. Statistical properties of different subsamples of sources are investigated. From the results of cross-identification with the radio catalogues of the database CATS (Verkhodanov et al., 1997BaltA...6..275V), continuous radio spectra of objects are plotted, identification with optical and X-ray catalogues is carried out. From the steep spectrum objects sources are selected for further studies.
- ID:
- ivo://CDS.VizieR/J/A+A/600/A87
- Title:
- IRAS17020+4544 VLBA 5, 8, 15, 24GHz images
- Short Name:
- J/A+A/600/A87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent XMM-Newton observations have revealed that IRAS 17020+4544 is a very unusual example of black hole windproduced feedback by a moderately luminous AGN in a spiral galaxy. Since the source is known for being a radio emitter, we investigated about the presence and the properties of a non-thermal component. We observed IRAS 17020+4544 with the Very Long Baseline Array at 5, 8, 15, and 24GHz within a month of the 2014 XMM-Newton observations. We further analysed archival data taken in 2000 and 2012. Results. We detect the source at 5GHz and on short baselines at 8GHz. At 15 and 24 GHz, the source is below our baseline sensitivity for fringe fitting, indicating the lack of prominent compact features. The morphology is that of an asymmetric double, with significant diffuse emission. The spectrum between 5 and 8GHz is rather steep (S{nu}~nu^-(1.0+/-0.2)^). Our re-analysis of the archival data at 5 and 8GHz provides results consistent with the new observations, suggesting that flux density and structural variability are not important in this source. We put a limit on the separation speed between the main components of <0.06c. IRAS 17020+4544 shows interesting features of several classes of objects: its properties are typical of compact steep spectrum sources, low power compact sources, radio-emitting narrow line Seyfert 1 galaxies. However, it can not be classified in any of these categories, remaining so far a one-of-a-kind object.
