- ID:
- ivo://CDS.VizieR/J/ApJ/846/159
- Title:
- Interferometric CO obs. of 126 CALIFA galaxies
- Short Name:
- J/ApJ/846/159
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present interferometric CO observations, made with the Combined Array for Millimeter-wave Astronomy (CARMA) interferometer, of galaxies from the Extragalactic Database for Galaxy Evolution survey (EDGE). These galaxies are selected from the Calar Alto Legacy Integral Field Area (CALIFA) sample, mapped with optical integral field spectroscopy. EDGE provides good-quality CO data (3{sigma} sensitivity {Sigma}_mol_~11M_{sun}/pc^2^ before inclination correction, resolution ~1.4kpc) for 126 galaxies, constituting the largest interferometric CO survey of galaxies in the nearby universe. We describe the survey and data characteristics and products, then present initial science results. We find that the exponential scale lengths of the molecular, stellar, and star-forming disks are approximately equal, and galaxies that are more compact in molecular gas than in stars tend to show signs of interaction. We characterize the molecular-to-stellar ratio as a function of Hubble type and stellar mass and present preliminary results on the resolved relations between the molecular gas, stars, and star-formation rate. We then discuss the dependence of the resolved molecular depletion time on stellar surface density, nebular extinction, and gas metallicity. EDGE provides a key data set to address outstanding topics regarding gas and its role in star formation and galaxy evolution, which will be publicly available on completion of the quality assessment.
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- ID:
- ivo://CDS.VizieR/VIII/66
- Title:
- IRAM observations in pre-star forming regions
- Short Name:
- VIII/66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The goal of the IRAM key-project ``Small-scale structure of pre-star forming regions'' is to map three nearby (d~150pc), quiescent molecular clouds with a high angular and spectral resolution to study the molecular cloud structure down to the smallest linear scales currently accessible by single dish radio telescopes. The key-project maps are available as data cubes (velocity, right ascension or galactic longitude, declination or galactic latitude) available as a set of 40 FITS files stored in the fits subdirectory; a summary of these 40 files is contained in the file "list.dat". The observations reported concern the molecular clouds L1512, L134A, and MCLD 123.5+24.9 in the Polaris Flare. The released data set of the IRAM key-project (Falgarone et al., 1998A&A...331..669F) are error beam corrected using the beam pattern parameters published by Garcia-Burillo, Guelin and Cernicharo (1993A&A...274..123G) and observations made with the KOSMA 3m telescope. Bensch et al. (2001A&A...365..275B) present the corrected maps using the 30m beam pattern recently published by Greve et al. (1998A&AS..133..271G). They estimate the accuracy of the maps of the key-project as 10-15% for the CO(2-1), except for two ^13^CO(2-1) maps of the MCLD 123.5+24.9/Polaris Flare and of L1512 where the uncertainties are estimated to 22% and 18% respectively. For the CO(1-0) data, the overall accuracy is 11%.
- ID:
- ivo://CDS.VizieR/J/A+A/629/A8
- Title:
- IRAS 16342-3814 12CO (1-0) and (3-2) datacubes
- Short Name:
- J/A+A/629/A8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Water-fountain nebulae are asymptotic giant branch (AGB) and post-AGB objects that exhibit high-velocity outflows traced by water-maser emission. Their study is important for understanding the interaction between collimated jets and the circumstellar material that leads to the formation of bipolar and/or multi-polar morphologies in evolved stars. The aim of this paper is to describe the three-dimensional morphology and kinematics of the molecular gas of the water-fountain nebula IRAS 16342-3814. Data was retrieved from the ALMA archive for analysis using a simple spatio-kinematical model. The software SHAPE was employed to construct a three-dimensional, spatio-kinematical model of the molecular gas in IRAS 16342-3814, and to then reproduce the intensity distribution and position-velocity diagram of the CO emission from the ALMA observations to derive the morphology and velocity field of the gas. Data from CO(J=1->0) supported the physical interpretation of the model. A spatio-kinematical model that includes a high-velocity collimated outflow embedded within material expanding at relatively lower velocity reproduces the images and position-velocity diagrams from the observations. The derived morphology is in good agreement with previous results from IR and water-maser emission observations. The high-velocity collimated outflow exhibits deceleration across its length, while the velocity of the surrounding component increases with distance. The morphology of the emitting region, the velocity field, and the mass of the gas as function of velocity are in excellent agreement with the properties predicted for a molecular outflow driven by a jet. The timescale of the molecular outflow is estimated to be ~70-100yr. The scalar momentum carried by the outflow is much larger than it can be provided by the radiation of the central star. An oscillating pattern was found associated with the high-velocity collimated outflow. The oscillation period of the pattern is T~=60-90yr and its opening angle is {theta}_op_~=2{deg}. The CO (J=3->2) emission in IRAS 16342-3814 is interpreted in terms of a jet-driven molecular outflow expanding along an elongated region. The position-velocity diagram and the mass spectrum reveal a feature due to entrained material that is associated with the driving jet. This feature is not seen in other more evolved objects that exhibit more developed bipolar morphologies. It is likely that the jet in those objects has already disappeared since it is expected to last only for a couple hundred years. This strengthens the idea that water fountain nebulae are undergoing a very short transition during which they develop the collimated outflows that shape the circumstellar envelopes. The oscillating pattern seen in the CO high-velocity outflow is interpreted as due to precession with a relatively small opening angle. The precession period is compatible with the period of the corkscrew pattern seen at IR wavelengths. We propose that the high-velocity molecular outflow traces the underlying primary jet that produces such a pattern.
- 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/A+A/648/A38
- Title:
- J1717-3342 and J1744-3116 CO spectra
- Short Name:
- J/A+A/648/A38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The chemistry of the diffuse interstellar medium is driven by the combined influences of cosmic rays, ultraviolet (UV) radiation, and turbulence. Previously detected at the outer edges of photodissociation regions (PDRs) and formed from the reaction of C^+^ and OH, CO^+^ is the main chemical precursor of HCO^+^ and CO in a thermal, cosmic-ray, and UV-driven chemistry. Our aim was to test whether the thermal cosmic-ray and UV-driven chemistry is producing CO in diffuse interstellar molecular gas through the intermediate formation of CO^+^ We searched for CO^+^ absorption with the Atacama Large Millimeter Array (ALMA) toward two quasars with known Galactic foreground absorption from diffuse interstellar gas, J1717-3342 and J1744-3116, targeting the two strongest hyperfine components of the J=2-1 transition near 236GHz. We could not detect CO^+^ but obtained sensitive upper limits toward both targets. The derived upper limits on the CO^+^ column densities represent about 4% of the HCO^+^ column densities. The corresponding upper limit on the CO^+^ abundance relative to H_2_ is <1.2x10^-10^. The non-detection of CO^+^ confirms that HCO^+^ is mainly produced in the reaction between oxygen and carbon hydrides, CH2^+^ or CH3^+^, induced by suprathermal processes, while CO^+^ and HOC^+^ result from reactions of C^+^ with OH and H_2_O. The densities r equired to form CO molecules at low extinction are consistent with this scheme.
- ID:
- ivo://CDS.VizieR/J/MNRAS/435/3376
- Title:
- L_FIR_ and L_CO_ for 247 extragalactic systems
- Short Name:
- J/MNRAS/435/3376
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An analysis of 44GHz Very Large Array observations of the z=1.574 radio-loud quasar 3C 318 has revealed emission from the redshifted J=1-->0 transition of the CO molecule and spatially resolved the 6.3kpc radio jet associated with the quasar at 115GHz rest frame. The continuum-subtracted line emitter is spatially offset from the quasar nucleus by 0.33arcsec (2.82kpc in projection). This spatial offset has a significance of >8{sigma} and, together with a previously published -400km/s velocity offset measured in the J=2-->1 CO line relative to the systemic redshift of the quasar, rules out a circumnuclear starburst or molecular gas ring and suggests that the quasar host galaxy is either undergoing a major merger with a gas-rich galaxy or is otherwise a highly disrupted system. If the merger scenario is correct, then the event may be in its early stages, acting as the trigger for both the young radio jets in the quasar and a starburst in the merging galaxy. The total molecular gas mass in the spatially offset line emitter as measured from the ground-state CO line MH_2_=3.7(+/-0.4)x10^10^ ({alpha}CO/0.8)M_{sun}_. Assuming that the line emitter can be modelled as a rotating disc, an inclination-dependent upper limit is derived for its dynamical mass M_dyn_sin^2^(i)<3.2x10^9^M_{sun}_, suggesting that for MH2 to remain less than M_dyn_ the inclination angle must be i<16{deg}. The far-infrared and CO luminosities of 246 extragalactic systems are collated from the literature for comparison. The high molecular gas content of 3C 318 is consistent with that of the general population of high-redshift quasars and submillimetre galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/380/665
- Title:
- Massive dense cores with ^13^CO J=1-0 lines
- Short Name:
- J/A+A/380/665
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper reports ^13^CO J=1-0 line observations toward 107 IRAS or H2O maser sources with the 13.7m telescope of the Purple Mountain Observatory (PMO). Parameters of emission components are obtained and the profile characteristics are identified. Table1 lists the observed results. It contains source name and its coordinates. ^13^CO line parameters and profile characteristics are given out. Distance, IRAS color indices and bolometric luminosity are also presented.
- ID:
- ivo://CDS.VizieR/J/MNRAS/453/645
- Title:
- Massive molecular outflows distance-limited sample
- Short Name:
- J/MNRAS/453/645
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have observed 99 mid-infrared-bright, massive young stellar objects and compact HII regions drawn from the Red MSX source survey in the J=3-2 transition of ^12^CO and ^13^CO, using the James Clerk Maxwell Telescope. 89 targets are within 6kpc of the Sun, covering a representative range of luminosities and core masses. These constitute a relatively unbiased sample of bipolar molecular outflows associated with massive star formation. Of these, 59, 17 and 13 sources (66, 19 and 15 percent) are found to have outflows, show some evidence of outflow, and have no evidence of outflow, respectively. The time-dependent parameters of the high-velocity molecular flows are calculated using a spatially variable dynamic time-scale. The canonical correlations between the outflow parameters and source luminosity are recovered and shown to scale with those of low-mass sources. For coeval star formation, we find the scaling is consistent with all the protostars in an embedded cluster providing the outflow force, with massive stars up to ~30M_{sun}_ generating outflows. Taken at face value, the results support the model of a scaled-up version of the accretion-related outflow-generation mechanism associated with discs and jets in low-mass objects with time-averaged accretion rates of ~ 10^-3^M_{sun}_/yr on to the cores. However, we also suggest an alternative model, in which the molecular outflow dynamics are dominated by the entrained mass and are unrelated to the details of the acceleration mechanism. We find no evidence that outflows contribute significantly to the turbulent kinetic energy of the surrounding dense cores.
- ID:
- ivo://CDS.VizieR/J/ApJS/235/3
- Title:
- Massive outflows associated with ATLASGAL clumps
- Short Name:
- J/ApJS/235/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have undertaken the largest survey for outflows within the Galactic plane using simultaneously observed ^13^CO and C^18^O data. Out of a total of 919 ATLASGAL clumps, 328 have data suitable to identify outflows, and 228 (69%+/-3%) show high-velocity outflows. The clumps with detected outflows show significantly higher clump masses (M_clump_), bolometric luminosities (L_bol_), luminosity-to-mass ratios (L_bol_/M_clump_), and peak H_2_ column densities (N_H2_) compared to those without outflows. Outflow activity has been detected within the youngest quiescent clump (i.e., 70{mu}m weak) in this sample, and we find that the outflow detection rate increases with M_clump_, L_bol_, L_bol_/M_clump_, and N_H2_, approaching 90% in some cases (UC HII regions = 93%+/-3%; masers = 86%+/-4%; HC HII regions = 100%). This high detection rate suggests that outflows are ubiquitous phenomena of massive star formation (MSF). The mean outflow mass entrainment rate implies a mean accretion rate of ~10^-4^M_{sun}_/yr, in full agreement with the accretion rate predicted by theoretical models of MSF. Outflow properties are tightly correlated with M_clump_, L_bol_, and L_bol_/M_clump_ and show the strongest relation with the bolometric clump luminosity. This suggests that outflows might be driven by the most massive and luminous source within the clump. The correlations are similar for both low-mass and high-mass outflows over 7 orders of magnitude, indicating that they may share a similar outflow mechanism. Outflow energy is comparable to the turbulent energy within the clump; however, we find no evidence that outflows increase the level of clump turbulence as the clumps evolve. This implies that the origin of turbulence within clumps is fixed before the onset of star formation.
- ID:
- ivo://CDS.VizieR/J/ApJ/876/70
- Title:
- Massive YSOs in the IR dark cloud G79.3+0.3
- Short Name:
- J/ApJ/876/70
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- G79.3+0.3 is an infrared dark cloud in the Cygnus-X complex that is home to massive deeply embedded young stellar objects (YSOs). We have produced a Submillimeter Array (SMA) 1.3mm continuum image and ^12^CO line maps of the eastern section of G79.3+0.3 in which we detect five separate YSOs. We have estimated physical parameters for these five YSOs and others in the vicinity of G79.3+0.3 by fitting existing photometry from Spitzer, Herschel, and ground-based telescopes to spectral energy distribution models. Through these model fits we find that the most massive YSOs seen in the SMA 1.3mm continuum emission have masses in the 5-6M_{sun}_ range. One of the SMA sources was observed to power a massive collimated ^12^CO outflow extending at least 0.94pc in both directions from the protostar, with a total mass of 0.83M_{sun}_ and a dynamical timescale of 23kyr.
