- ID:
- ivo://CDS.VizieR/J/A+A/564/A65
- Title:
- Cold gas properties of Herschel Reference Survey
- Short Name:
- J/A+A/564/A65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new ^12^CO(1-0) observations of 59 late-type galaxies belonging to the Herschel Reference Survey (HRS), a complete K-band-selected, volume-limited (15<=D<=25Mpc) sample of nearby galaxies spanning a wide range in morphological type and luminosity. We studied different recipes to correct single-beam observations of nearby galaxies of different sizes and inclinations for aperture effects. This was done by comparing single-beam and multiple-beam observations along the major axis, which were corrected for aperture effects using different empirical or analytical prescriptions, to integrated maps of several nearby galaxies, including edge-on systems observed by different surveys. The resulting recipe is an analytical function determined by assuming that late-type galaxies are 3D exponentially declining discs with a characteristic scale length r_CO_=0.2r_24.5_, where r_24.5_ is the optical, g- (or B-) band isophotal radius at the 24.5mag/arcsec^2^ (25mag/arcsec^2^), as well as a scale height z_CO_=1/100r_24.5_. Our new CO data are then combined with those available in the literature to produce the most updated catalogue of CO observations for the HRS, now including 225 out of the 322 galaxies of the complete sample. The 3D exponential disc integration is applied to all the galaxies of the sample to measure their total CO fluxes, which are later transformed into molecular gas masses using a constant and a luminosity-dependent X_CO_ conversion factor. We also collect HI data for 315 HRS galaxies from the literature and present it in a homogenised form.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/897/74
- Title:
- Cold & molecular clumps and YSOs within G15.684-0.29
- Short Name:
- J/ApJ/897/74
- Date:
- 11 Mar 2022
- Publisher:
- CDS
- Description:
- The bubble G15.684-0.29 has a radius of 15.7pc. Its large size indicates that it may have enough time to trigger star formation. We identify 39 dense cold clumps around the bubble from the HI-GAL survey. All of them satisfy the criteria for forming massive stars, and most of them lie in the bubble shell. We identify 19 molecular clumps around the bubble from the 12CO(3-2) survey, all of which are gravitationally bound. We found 9 Class I YSOs, 28 Class II YSOs, and 12 transition disks (TDs) around the bubble. For those young stellar objects (YSOs) located within the bubble boundary, 6 of 7 Class I YSOs lie in the shell, 15 of 22 Class II YSOs lie inside the bubble, and 3 of 5 TDs lie inside the bubble. The dynamical age of G15.684-0.29 in a turbulent medium is ~4Myr, which is much greater than the shell fragmentation time, ~0.82-1.74Myr. We suggest that triggered star formation may be ongoing in the shell of the bubble, and the collect and collapse model may work here. However, we cannot rule out the possibility that the radiation-driven implosion model may work on the formation of some YSOs. As we expected, the larger bubble has a much longer dynamical age, but we failed to find a clear age gradient for YSOs around the bubble.
- ID:
- ivo://CDS.VizieR/J/A+A/508/1331
- Title:
- CO maps of 3 galactic supernova remnants
- Short Name:
- J/A+A/508/1331
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The field just West of the galactic supernova remnant W28 (l=6.4{deg}, b=-0.2{deg}) harbors 3 of 5 newly-discovered 1720 OH maser spots and two recently-discovered candidate supernova candidates (one of which is a gamma-ray source), as well as several compact and classical HII regions. The aims is to show the interaction of radio supernova remnants with ambient molecular gas in sky field just West of W28.
- ID:
- ivo://CDS.VizieR/J/A+A/483/839
- Title:
- CO(2-1) maps of IRAS 18059-3211
- Short Name:
- J/A+A/483/839
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the nature of Gomez's Hamburger (IRAS 18059-3211), a nebula that has been proposed to be a post-AGB object. Such a classification has not been confirmed; instead, we argue that it will be a key object in the study of disks rotating around young stars. We present high-resolution SMA maps of CO J=2-1 (230.538GHz) in Gomez's Hamburger. The data are analyzed by means of a code that simulates the emission of a nebula showing a variety of physical conditions and kinematics. Our observations clearly show that the CO emitting gas in Gomez's Hamburger forms a spectacular disk in keplerian rotation. Model calculations undoubtedly confirm this result. The central (mainly stellar) mass is found to be high, ~4 solar masses for a distance of 500pc. The mass and (relatively low) luminosity of the source are, independent of the assumed distance, very different from those possible in evolved stars. This object is probably transitional between the pre-MS and MS phases, still showing interstellar material around the central star or stellar system.
- ID:
- ivo://CDS.VizieR/J/A+A/496/45
- Title:
- CO maps of three lensed submillimetre galaxies
- Short Name:
- J/A+A/496/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Submillimetre galaxies (SMGs) are distant, dusty galaxies undergoing star formation at prodigious rates. Recently there has been major progress in understanding the nature of the bright SMGs (i.e. S_850um_>5mJy). The samples for the fainter SMGs are small and are currently in a phase of being built up through identification studies. We study the molecular gas content in the two SMGs, SMMJ163555 and SMMJ163541, at redshifts z=1.034 and z=3.187 with unlensed submillimetre fluxes of 0.4mJy and 6.0mJy. Both SMGs are gravitationally lensed by the foreground cluster Abell 2218. We used the IRAM Plateau de Bure Interferometer to obtain observations at 3mm of the lines CO(2-1) for SMMJ163555 and CO(3-2) for SMMJ163541. Additionally, we obtained CO(4-3) observations for the candidate z=4.048 SMMJ163556 with an unlensed submillimetre flux of 2.7mJy. Results: The CO(2-1) line was detected for SMMJ163555 at redshift 1.0313 with an integrated line intensity of 1.2+/-0.2Jy.km/s and a line width of 410+/-120km/s. From this a gas mass of 1.6x10^9^M_{sun}_ is derived and a star formation efficiency of 440L_{sun}_/M_{sun}_ estimated. The CO(3-2) line was detected for SMMJ163541 at redshift 3.1824, possibly with a second component at redshift 3.1883, with an integrated line intensity of 1.0+/-0.1Jy.km/s and a line width of 280+/-50km/s. From this a gas mass of 2.2x10^10^M_{sun}_ is derived and a star formation efficiency of 1000L_{sun}_/M_{sun}_ is estimated. For SMMJ163556, the CO(4-3) is undetected within the redshift range 4.035-4.082 down to a sensitivity of 0.15Jy.km/s.
- ID:
- ivo://CDS.VizieR/J/A+A/619/A127
- Title:
- Comet C/2016 R2 (PanSTARRS) IRAM spectra
- Short Name:
- J/A+A/619/A127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multi-wavelength study of comet C/2016 R2 (PanSTARRS). This comet was observed on 23-24 January 2018 with the IRAM 30m telescope, and in January to March 2018 with the Nancay radio telescope. Visible spectroscopy was performed in December 2017 and February 2018 with small amateur telescopes. We report on measurements of CO, CH_3_OH, H_2_CO and HCN production rates, and on the determination of the N2/CO abundance ratio. Several other species, especially OH, were searched for but not detected. The inferred relative abundances, including upper limits for sulfur species, are compared to those measured in other comets at about the same heliocentric distance of ~2.8AU. The coma composition of comet C/2016 R2 is very different from all other comets observed so far, being rich in N2 and CO and dust poor. This suggests that this comet might belong to a very rare group of comets formed beyond the N_2_ ice line. Alternatively, comet C/2016 R2 (PanSTARRS) could be the fragment of a large and differentiated transneptunian object, with properties characteristic of volatile-enriched layers.
- ID:
- ivo://CDS.VizieR/J/PASJ/60/1297
- Title:
- CO molecular clouds in Carina flare supershell
- Short Name:
- J/PASJ/60/1297
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of ^12^CO(J=1-0) and ^13^CO(J=1-0) molecular clouds in the spatio-velocity range of the Carina Flare supershell, GSH287+04-17. The data cover a region of ~66 square degrees and were taken with the NANTEN 4m telescope, at spatial and velocity resolutions of ~2.6' and 0.1km/s. Decomposition of the emission results in the identification of 156 ^12^CO clouds and 60 ^13^CO clouds, for which we provide observational and physical parameters.
- ID:
- ivo://CDS.VizieR/J/PASJ/53/1081
- Title:
- CO molecular clouds in Lupus
- Short Name:
- J/PASJ/53/1081
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Lupus star-forming region has been surveyed for molecular clouds in ^12^CO with the NANTEN radio telescope, and a cloud mass of 1.7x10^4^M_{sun}_ has been revealed. We were able to detect 105 molecular clouds, most of which are relatively small and of low mass. The members of the Sco OB 2 association and the X-ray detected pre-main-sequence stars (PMSs) are distributed all around this region. The OB stars and the molecular clouds show exclusive distributions. Large fractions of the PMSs are located away from the molecular clouds, and are thus isolated. The origin of the isolated PMSs is discussed. About 40% of the PMSs have candidates of their parent clouds less massive than 20M_{sun}_ within 4pc, which suggests in-situ star formation in the small clouds and their rapid dissipation. The separations from the PMSs to the clouds are typically larger than those in the Chamaeleon region, probably because of coexisting OB stars. From the cloud structures and the distributions of the OB stars, PMSs, and H I expanding shell, it is suggested that the molecular clouds have been effectively dissipated by the OB stars and a shock wave, which may also have triggered star formation in Lupus and the {rho} Oph clouds.
- ID:
- ivo://CDS.VizieR/J/ApJ/867/165
- Title:
- CO molecular clumps in Henize 2-10 dwarf galaxy
- Short Name:
- J/ApJ/867/165
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Atacama Large Millimeter/Submillimeter Array CO(3-2) observations at 0.3" resolution of He 2-10, a starburst dwarf galaxy and possible high-z galaxy analog. The warm dense gas traced by CO(3-2) is found in clumpy filaments that are kinematically and spatially distinct. The filaments have no preferred orientation or direction; this may indicate that the galaxy is not evolving into a disk galaxy. Filaments appear to be feeding the active starburst; the velocity field in one filament suggests acceleration onto an embedded star cluster. The relative strengths of CO(3-2) and radio continuum vary strongly on decaparsec scales in the starburst. There is no CO(3-2) clump coincident with the nonthermal radio source that has been suggested to be an AGN, nor unusual kinematics. The kinematics of the molecular gas show significant activity that is apparently unrelated to the current starburst. The longest filament, east of the starburst, has a pronounced shear of FWHM ~40km/s across its ~50pc width over its entire ~0.5kpc length. The cause of the shear is not clear. This filament is close in projection to a "dynamically distinct" CO feature previously seen in CO(1-0). The most complex region and the most highly disturbed gas velocities are in a region 200pc south of the starburst. The CO(3-2) emission there reveals a molecular outflow, of line width FWZI~120-140km/s, requiring an energy >~10^53^erg/s. There is at present no candidate for the driving source of this outflow.
- ID:
- ivo://CDS.VizieR/J/A+A/629/A112
- Title:
- Complex refractive index of CO ice
- Short Name:
- J/A+A/629/A112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Reliable, directly measured optical properties of astrophysical ice analogs in the infrared (IR) and terahertz (THz) range are missing. These parameters are of great importance to model the dust continuum radiative transfer in dense and cold regions, where thick ice mantles are present, and are necessary for the interpretation of future observations planned in the far-IR region. Coherent THz radiation allows direct measurement of the complex dielectric function (refractive index) of astrophysically relevant ice species in the THz range. The time-domain waveforms and the frequency-domain spectra of reference samples of CO ice, deposited at a temperature of 28.5K and annealed to 33K at different thicknesses, have been recorded. A new algorithm is developed to reconstruct the real and imaginary parts of the refractive index from the time-domain THz data. The complex refractive index in the wavelength range of 1mm-150um (0.3-2.0THz) has been determined for the studied ice samples, and compared with available data found in the literature. The developed algorithm of reconstructing the real and imaginary parts of the refractive index from the time-domain THz data enables, for the first time, the determination of optical properties of astrophysical ice analogs without using the Kramers-Kronig relations. The obtained data provide a benchmark to interpret the observational data from current ground based facilities as well as future space telescope missions, and have been used to estimate the opacities of the dust grains in presence of CO ice mantles.
