- ID:
- ivo://CDS.VizieR/J/A+A/510/A5
- Title:
- CO(2-1) maps of IRAS 00117+6412
- Short Name:
- J/A+A/510/A5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our main aim is to study the influence of the initial conditions of a cloud in the intermediate/high-mass star formation process. We observed with the VLA, PdBI, and SMA the centimeter and millimeter continuum, N_2_H^+^ (1-0), and CO (2-1) emission associated with a dusty cloud harboring a nascent cluster with intermediate-mass protostars.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/441/224
- Title:
- Compact FIR-bright sources in M33
- Short Name:
- J/MNRAS/441/224
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multiwavelength study of a sample of far-infrared (FIR) sources detected on the Herschel broad-band maps of the nearby galaxy M33. We perform source photometry on the FIR maps as well as mid-infrared (MIR), H{alpha}, far-ultraviolet and integrated Hi and CO line emission maps. By fitting MIR/FIR dust emission spectra, the source dust masses, temperatures and luminosities are inferred. The sources are classified based on their H{alpha} morphology (sub-structured versus not-substructured) and on whether they have a significant CO detection (S/N>3{sigma}). We find that the sources have dust masses in the range 10^2^-10^4^M_{sun}_ and that they present significant differences in their inferred dust/star formation/gas parameters depending on their H{alpha} morphology and CO detection classification. The results suggests differences in the evolutionary states or in the number of embedded HII regions between the sub-samples. The source background-subtracted dust emission seems to be predominantly powered by local star formation, as indicated by a strong correlation between the dust luminosity and the dust-corrected H{alpha} luminosity and the fact that the extrapolated young stellar luminosity is high enough to account for the observed dust emission. Finally, we do not find a strong correlation between the dust-corrected H{alpha} luminosity and the dust mass of the sources, consistent with previous results on the breakdown of simple scaling relations at sub-kpc scales. However, the scatter in the relation is significantly reduced by correcting the H{alpha} luminosity for the age of the young stellar populations in the star-forming regions.
- ID:
- ivo://CDS.VizieR/J/ApJ/809/10
- Title:
- Compact radio sources within 30" of Sgr A*
- Short Name:
- J/ApJ/809/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent broadband 34 and 44GHz radio continuum observations of the Galactic center have revealed 41 massive stars identified with near-IR (NIR) counterparts, as well as 44 proplyd candidates within 30" of SgrA*. Radio observations obtained in 2011 and 2014 have been used to derive proper motions of eight young stars near Sgr A*. The accuracy of proper motion estimates based on NIR observations by Lu et al. (2009ApJ...690.1463L) and Paumard et al. (2006, J/ApJ/643/1011) have been investigated by using their proper motions to predict the 2014 epoch positions of NIR stars and comparing the predicted positions with those of radio counterparts in the 2014 radio observations. Predicted positions from Lu et al. show an rms scatter of 6mas relative to the radio positions, while those from Paumard et al. show rms residuals of 20mas. We also determine the mass-loss rates of 11 radio stars, finding rates that are on average ~2 times smaller than those determined from model atmosphere calculations and NIR data. Clumpiness of ionized winds would reduce the mass loss rate of WR and O stars by additional factors of 3 and 10, respectively. One important implication of this is a reduction in the expected mass accretion rate onto Sgr A* from stellar winds by nearly an order of magnitude to a value of a few x10^-7^m_{sun}_/yr. Finally, we present the positions of 318 compact radio sources within 30" of Sgr A*, 45 of which have stellar counterparts in the NIR K_s_ (2.18{mu}m) and L' (3.8{mu}m) bands.
- ID:
- ivo://CDS.VizieR/J/ApJS/178/280
- Title:
- Compendium of ISO far-IR extragalactic data
- Short Name:
- J/ApJS/178/280
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Far-infrared line and continuum fluxes are presented for a sample of 227 galaxies observed with the Long Wavelength Spectrometer on the Infrared Space Observatory (ISO, Kessler et al., 1996A&A...315L..27K). The galaxy sample includes normal star-forming systems, starbursts, and active galactic nuclei covering a wide range of colors and morphologies. The data set spans some 1300 line fluxes, 600 line upper limits, and 800 continuum fluxes. Several fine-structure emission lines are detected that arise in either photodissociation or HII regions: [OIII] 52um, [NIII] 57um, [OI] 63um, [OIII] 88um, [NII] 122um, [OI] 145um, and [CII] 158um. Molecular lines such as OH at 53, 79, 84, 119, and 163um, and H_2_O at 58, 66, 75, 101, and 108um are also detected in some galaxies. In addition to those lines emitted by the target galaxies, serendipitous detections of Milky Way [CII] 158um and an unidentified line near 74um in NGC 1068 are also reported. Finally, continuum fluxes at 52, 57, 63, 88, 122, 145, 158, and 170um are derived for a subset of galaxies in which the far-infrared emission is contained within the ~75" ISO LWS beam. The statistics of this large database of continuum and line fluxes, including trends in line ratios with the far-infrared color and infrared-to-optical ratio, are explored.
- ID:
- ivo://CDS.VizieR/J/ApJS/156/169
- Title:
- Confirmed class 0 sources list
- Short Name:
- J/ApJS/156/169
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We searched the literature to obtain a complete list of known Class 0 sources. A list of 95 confirmed or candidate objects was compiled. To the best of our knowledge, all published broadband observations from 1{mu}m to 3.5mm have been collected and are assembled in a catalog. These data were used to determine physical properties (T_bol_, L_bol_, L_smm_/L_bol_, M_env_) and for a uniform classification. Fifty sources possess sufficient observational data and are classified as Class 0 or Class 0/1 objects. The source properties are compared with different evolutionary models to infer ages and masses, and their correlations are investigated. About 25% of the sources are found to be in a quiet accretion phase or possess a significantly different time evolution of the accretion rate than the average. In Taurus, with its isolated star formation mode, this seems especially to be the case.
- ID:
- ivo://CDS.VizieR/J/A+A/627/A107
- Title:
- CO observations of major merger pairs at z=0
- Short Name:
- J/A+A/627/A107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CO observations of 78 spiral galaxies in local merger pairs. These galaxies represent a subsample of a Ks-band-selected sample consisting of 88 close major-merger pairs (HKPAIRs), 44 spiral-spiral (S+S) pairs, and 44 spiral-elliptical (S+E) pairs, with separation <20h^-1^kpc and mass ratio <2.5. For all objects, the star formation rate (SFR) and dust mass were derived from Herschel PACS and SPIRE data, and the atomic gas mass, MHI, from the Green Bank Telescope HI observations. The complete data set allows us to study the relation between gas (atomic and molecular) mass, dust mass, and SFR in merger galaxies. We derive the molecular gas fraction (M_H2_/M*), molecular-to-atomic gas mass ratio (M_H2_/M_HI_), gas-to-dust mass ratio and SFE (=SFR/M_H2_) and study their dependences on pair type (S+S compared to S+E), stellar mass, and the presence of morphological interaction signs. We find an overall moderate enhancement (~2x) in both molecular gas fraction (M_H2_/M*) and molecular-to-atomic gas ratio (M_H2_/M_HI_) for star-forming galaxies in major-merger pairs compared to non-interacting comparison samples, whereas no enhancement was found for the SFE nor for the total gas mass fraction ((MHI+MH2)/M^Cstar). When divided into S+S and S+E, low mass and high mass, and with and without interaction signs, there is a small difference in SFE, a moderate difference in M_H2_/M*, and a strong difference in M_H2_/M_HI_ between subsamples. For the molecular-to-atomic gas ratio M_H2_/M_HI_, the difference between S+S and S+E subsamples is 0.55+/-0.18dex and between pairs with and without interaction signs is 0.65+/-0.16dex. Together, our results suggest that (1) star formation enhancement in close major-merger pairs occurs mainly in S+S pairs after the first close encounter (indicated by interaction signs)^Mbecause the HI gas is compressed into star-forming molecular gas by the tidal torque; and (2) this effect is much weakened in the S+E pairs.
- ID:
- ivo://CDS.VizieR/J/A+A/618/A143
- Title:
- Cool, evolved stars PACS and SPIRE spectroscopy
- Short Name:
- J/A+A/618/A143
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- At the end of their lives AGB stars are prolific producers of dust and gas. The details of this mass-loss process are still not understood very well. Herschel PACS and SPIRE spectra which cover the wavelength range from ~55 to 670um almost continuously, offer a unique way of investigating properties of AGB stars in general and the mass-loss process in particular as this is the wavelength region where dust emission is prominent and molecules have many emission lines. We present the community with a catalogue of AGB stars and red supergiants (RSGs) with PACS and/or SPIRE spectra reduced according to the current state of the art. The Herschel Interactive Processing Environment (HIPE) software with the latest calibration is used to process the available PACS and SPIRE spectra of 40 evolved stars. The SPIRE spectra of some objects close to the Galactic plane require special treatment because of the weaker fluxes in combination with the strong and complex background emission at those wavelengths. The spectra are convolved with the response curves of the PACS and SPIRE bolometers and compared to the fluxes measured in imaging data of these sources. Custom software is used to identify lines in the spectra, and to determine the central wavelengths and line intensities. Standard molecular line databases are used to associate the observed lines. Because of the limited spectral resolution of the PACS and SPIRE spectrometers (~1500), several known lines are typically potential counterparts to any observed line. To help identifications in follow-up studies the relative contributions in line intensity of the potential counterpart lines are listed for three characteristic temperatures based on local thermodynamic equilibrium (LTE) calculations and assuming optically thin emission. The following data products are released: the reduced spectra, the lines that are measured in the spectra with wavelength, intensity, potential identifications, and the continuum spectra, i.e. the full spectra with all identified lines removed. As simple examples of how this data can be used in future studies we have fitted the continuum spectra with three power laws (two wavelength regimes covering PACS, and one covering SPIRE) and find that the few OH/IR stars seem to have significantly steeper slopes than the other oxygen- and carbon-rich objects in the sample, possibly related to a recent increase in mass-loss rate. As another example we constructed rotational diagrams for CO (and HCN for the carbon stars) and fitted a two-component model to derive rotational temperatures.
- ID:
- ivo://CDS.VizieR/J/A+A/607/A110
- Title:
- CO properties of compact group galaxies
- Short Name:
- J/A+A/607/A110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Compact groups (CGs) provide an environment in which interactions between galaxies and with the intra-group medium enable and accelerate galaxy transitions from actively star forming to quiescent. Galaxies in transition from active to quiescent can be selected, by their infrared (IR) colors, as canyon or infrared transition zone (IRTZ) galaxies. We used a sample of CG galaxies with IR data from the Wide Field Infrared Survey Explorer (WISE) allowing us to calculate the stellar mass and star formation rate (SFR) for each galaxy. Furthermore, we present new CO(1-0) data for 27 galaxies and collect data from the literature to calculate the molecular gas mass for a total sample of 130 galaxies. This data set allows us to study the difference in the molecular gas fraction (Mmol/Mstar) and star formation efficiency (SFE=SFR/Mmol) between active, quiescent, and transitioning (i.e., canyon and IRTZ) galaxies. We find that transitioning galaxies have a mean molecular gas fraction and a mean SFE that are significantly lower than those of actively star-forming galaxies. The molecular gas fraction is higher than that of quiescent galaxies, whereas the SFE is similar. These results indicate that the transition from actively star-forming to quiescent in CG galaxies goes along with a loss of molecular gas, possibly due to tidal forces exerted from the neighboring galaxies or a decrease in the gas density. In addition, the remaining molecular gas loses its ability to form stars efficiently, possibly owing to turbulence perturbing the gas, as seen in other, well-studied examples such as Stephan's Quintet and HCG 57. Thus, the amount and properties of molecular gas play a crucial role in the environmentally driven transition of galaxies from actively star forming to quiescent.
- ID:
- ivo://CDS.VizieR/J/MNRAS/422/1071
- Title:
- Cores in IR Dark Clouds for 300<=l<=330
- Short Name:
- J/MNRAS/422/1071
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used data taken as part of the Herschel infrared Galactic Plane survey (Hi-GAL) to study 3171 infrared dark cloud (IRDC) candidates that were identified in the mid-IR (8um) by Spitzer (we refer to these as 'Spitzer-dark' regions). They all lie in the range l=300-330{deg} and |b|<=1{deg}. Of these, only 1205 were seen in emission in the far-IR (250-500um) by Herschel (we call these 'Herschel-bright' clouds). It is predicted that a dense cloud will not only be seen in absorption in the mid-IR, but will also be seen in emission in the far-IR at the longest Herschel wavebands (250-500um). If a region is dark at all wavelengths throughout the mid-IR and far-IR, then it is most likely to be simply a region of lower background IR emission (a 'hole in the sky'). Hence, it appears that previous surveys, based on Spitzer and other mid-IR data alone, may have overestimated the total IRDC population by a factor of ~2. This has implications for estimates of the star formation rate in IRDCs in the Galaxy. We studied the 1205 Herschel-bright IRDCs at 250um and found that 972 of them had at least one clearly defined 250-um peak, indicating that they contained one or more dense cores. Of these, 653 (67 per cent) contained an 8-um point source somewhere within the cloud, 149 (15 per cent) contained a 24-um point source but no 8-um source and 170 (18 per cent) contained no 24- or 8-um point sources. We use these statistics to make inferences about the lifetimes of the various evolutionary stages of IRDCs.
180. COSMOS 70um sources
- ID:
- ivo://CDS.VizieR/J/ApJ/709/572
- Title:
- COSMOS 70um sources
- Short Name:
- J/ApJ/709/572
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a large robust sample of 1503 reliable and unconfused 70um selected sources from the multiwavelength data set of the Cosmic Evolution Survey. Using the Spitzer IRAC and MIPS photometry, we estimate the total infrared (IR) luminosity, LIR (8-1000um), by finding the best-fit template from several different template libraries. The long-wavelength 70 and 160um data allow us to obtain a reliable estimate of LIR, accurate to within 0.2 and 0.05dex, respectively. The 70um data point enables a significant improvement over the luminosity estimates possible with only a 24um detection. The full sample spans a wide range in IR luminosity, LIR~10^8^-10^14^L_{sun}_, with a median luminosity of 10^11.4^L_{sun}_. We identify a total of 687 luminous, 303 ultraluminous, and 31 hyperluminous infrared galaxies (LIRGs, ULIRGs, and HyLIRGs) over the redshift range 0.01<z<3.5 with a median redshift of 0.5. Presented here are the full spectral energy distributions (SEDs) for each of the sources compiled from the extensive multiwavelength data set from the ultraviolet (UV) to the far-infrared. A catalog of the general properties of the sample (including the photometry, redshifts, and LIR) is included with this paper.