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- ID:
- ivo://CDS.VizieR/J/other/PASA/17.92
- Title:
- CO emission towards Southern dark clouds
- Short Name:
- J/other/PASA/17.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the 22-m 'Mopra' antenna (near Coonabarabran, NSW) of the Australia Telescope National Facility (ATNF), we have observed emission from the 115-GHz J=1-0 transition of CO towards the centre of each of the 1101 clouds listed in the Hartley et al. Catalogue of Southern Dark Clouds (SDC, Cat. <VII/191>). The velocity range covered was -96 to +70km/s, with a velocity resolution of 0.120km/s. CO was detected at 1049 of the positions, with 367 spectra showing emission at more than one radial velocity. Here we present the most comprehensive general survey of the SDC catalogue, with the intensity, velocity and half-width of the CO detection and a code describing the profile shape. The presence of blue- or red-shifted wings in many observations can provide a starting point in searches for star-forming regions.
- ID:
- ivo://CDS.VizieR/J/A+A/594/A117
- Title:
- CO-H2 and complex organic molecules in TMC-1C
- Short Name:
- J/A+A/594/A117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Almost 200 different species have been detected in the interstellar medium (ISM) during the last decades, revealing not only simple species but complex molecules with more than 6 atoms. Other exotic compounds, like the weakly-bound dimer (H_2_)_2_, have also been detected in astronomical sources like Jupiter. We aim at detecting for the first time the CO-H_2_ van der Waals complex in the ISM, which if detected can be a sensitive indicator for low temperatures. We use the IRAM30m telescope, located in Pico Veleta (Spain), to search for the CO-H_2_ complex in a cold, dense core in TMC-1C (with a temperature of 10K). All the brightest CO-H_2_ transitions in the 3mm (80-110GHz) band have been observed with a spectral resolution of 0.5-0.7km/s, reaching a rms noise level of 2mK. The simultaneous observation of a broad frequency band, 16GHz, has allowed us to conduct a serendipitous spectral line survey. No lines belonging to the CO-H_2_ complex have been detected. We have set up a new, more stringent upper limit for its abundance to be [CO-H_2_]/[CO]=5x10^-6^, while we expect the abundance of the complex to be in the range 10^-8^-10^-3^. The spectral line survey has allowed us to detect 75 lines associated with 41 different species (including isotopologues). We detect a number of complex organic species, e.g. methyl cyanide (CH_3_CN), methanol (CH_3_OH), propyne (CH_3_CCH) and ketene (CH_2_CO), associated with cold gas (excitation temperatures about 7K), confirming the presence of these complex species not only in warm objects but also in cold regimes.
- ID:
- ivo://CDS.VizieR/J/A+A/399/795
- Title:
- Co III electron-impact broadening parameters
- Short Name:
- J/A+A/399/795
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In hot star atmospheres, the Stark broadening mechanism is the main pressure broadening mechanism. An interesting application where such a mechanism is of interest is the modeling and investigation of hot star spectra, stellar atmospheres and subphotospheric layers. Consequently, for the investigation and modeling of the Hg-Mn star and other type of hot star atmospheres, the Stark broadening parameters for Co III spectral lines may be of interest. Here we present Stark broadening data for 20 Co III spectral lines (from a^6^D-z^6^D^o^ and a^6^D-z^6^F^o^ Co III multiplets), as a function of temperature, calculated by using the modified semi-empirical approach. The importance of the electron-impact effect in the case of the Co III 194.98nm line for several stellar atmosphere models has been tested.
- ID:
- ivo://CDS.VizieR/J/A+AS/130/541
- Title:
- Co II oscillator strengths
- Short Name:
- J/A+AS/130/541
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In table 2 the log(gf) values for the 3d^8^+3d^7^ 4s-->3d^7^ 4p electric dipole (E1) transitions are given. This system is selected by cutting off energy values larger than 120,000cm^-1^ of both the even and the odd system in the final printing procedure; only log(gf) values larger than -3 are included. The first column of this table shows the wavelength obtained from the energy differences between the experimental level values. Wavelengths below 2000 Angstrom are given as vacuum wavelengths and above 2000 Angstrom as air wavelengths. The second column gives the log(gf) values followed by the J-value, energy value and the name of the lower (even) level. The first character of the level name designates the configuration number: for the even levels '1' refers to 3d^8^ and '2' to 3d^7^ 4s; for the odd levels '1' refers to 3d^7^ 4p. An '*' after the energy value indicates that the level is known, in which case the experimental level value is given. When unknown, the calculated energy value is given and used to approximate the wavelength. The A-values for the forbidden lines given in table 7 are restricted to the magnetic dipole (M1) and electric quadrupole (E2) transitions within the 3d^8^+3d^7^ 4s configurations, from levels with an energy of less than 50,000 cm^-1^ above the ground and with A-values larger than 10^-3^s^-1^. The level with the lower J-value is given first in the designation of the transition. The remaining columns are similar to the corresponding ones in table 2. The first character of the level name designates the configuration number: for the even levels '1' refers to 3d^8 and '2' to 3d^7 4s. An '*' after the energy value indicates that the level is known, in which case the experimental level value is given. When unknown, the calculated energy value is given and used to approximate the wavelength.
- ID:
- ivo://CDS.VizieR/J/A+AS/129/147
- Title:
- Co II radiative transition probabilities
- Short Name:
- J/A+AS/129/147
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radiative transition probabilities have been calculated for the magnetic dipole (M1) and electric quadrupole (E2) transitions connecting the 47 metastable energy levels in the 3d^8^, 3d^7^ 4s and 3d^6^ 4s^2^ configurations in Co II. The most important configuration interaction (CI) and relativistic effects have been taken into account in the computations carried out with the help of the relativistic Hartree-Fock (HFR) method combined with a semi-empirical optimization of the radial parameters.
- ID:
- ivo://CDS.VizieR/J/A+A/412/657
- Title:
- CO in cooling flow of clusters of galaxies
- Short Name:
- J/A+A/412/657
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of a CO line survey in central cluster galaxies with cooling flows are presented. Cold molecular gas is detected with the IRAM 30m telescope, through CO(1-0) and CO(2-1) emission lines in 6-10 among 32 galaxies. The corresponding gas masses are between 3x10^8^ and 4x10^10^M_{sun}. These results are in agreement with recent CO detections by Edge (2001MNRAS.328..762E). A strong correlation between the CO emission and the H{alpha} luminosity is also confirmed. Cold gas exists in the center of cooling flow clusters and these detections may be interpreted as evidence of the long searched for very cold residual of the hot cooling gas.
- ID:
- ivo://CDS.VizieR/J/ApJ/686/948
- Title:
- CO in extragalactic giant molecular clouds
- Short Name:
- J/ApJ/686/948
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use high spatial resolution observations of CO to systematically measure the resolved size-line width, luminosity-line width, luminosity-size, and mass-luminosity relations of GMCs in a variety of extragalactic systems. Although the data are heterogeneous, we analyze them in a consistent manner to remove the biases introduced by limited sensitivity and resolution, thus obtaining reliable sizes, velocity dispersions, and luminosities. We compare the results obtained in dwarf galaxies with those from the Local Group spiral galaxies. We find that extragalactic GMC properties measured across a wide range of environments are very much compatible with those in the Galaxy. The property that shows the largest variability is their resolved brightness temperature, although even that is similar to the average Galactic value in most sources.
- ID:
- ivo://CDS.VizieR/J/ApJS/181/255
- Title:
- CO in Galactic HII regions
- Short Name:
- J/ApJS/181/255
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive the molecular properties for a sample of 301 Galactic HII regions including 123 ultra compact (UC), 105 compact, and 73 diffuse nebulae. We analyze all sources within the BU-FCRAO Galactic Ring Survey (GRS) of ^13^CO emission known to be HII regions based upon the presence of radio continuum and cm-wavelength radio recombination line emission. Unlike all previous large area coverage ^13^CO surveys, the GRS is fully sampled in angle and yet covers ~75deg^2^ of the Inner Galaxy. The angular resolution of the GRS (46") allows us to associate molecular gas with HII regions without ambiguity and to investigate the physical properties of this molecular gas. We find clear CO/HII morphological associations in position and velocity for ~80% of the nebular sample. Compact HII region molecular gas clouds are on average larger than UC clouds: 2.2' compared to 1.7'.
- ID:
- ivo://CDS.VizieR/J/A+A/618/A126
- Title:
- CO in group-dominant ellipticals
- Short Name:
- J/A+A/618/A126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present IRAM 30m and APEX telescope observations of CO(1-0) and CO(2-1) lines in 36 group-dominant early-type galaxies, completing our molecular gas survey of dominant galaxies in the Complete Local-volume Groups Sample. We detect CO emission in 12 of the galaxies at >4{sigma} significance, with molecular gas masses in the range 0.01-6x10^8^M_{sun}_, as well as CO in absorption in the non-dominant group member galaxy NGC 5354. In total 21 of the 53 CLoGS dominant galaxies are detected in CO and we confirm our previous findings that they have low star formation rates (0.01-1M_{sun}_/yr) but short depletion times (<1Gyr) implying rapid replenishment of their gas reservoirs. Comparing molecular gas mass with radio luminosity, we find that a much higher fraction of our group-dominant galaxies (60+/-16%) are AGN-dominated than is the case for the general population of ellipticals, but that there is no clear connection between radio luminosity and the molecular gas mass. Using data from the literature, we find that at least 27 of the 53 CLoGS dominant galaxies contain HI, comparable to the fraction of nearby non-cluster early type galaxies detected in HI and significantly higher that the fraction in the Virgo cluster. We see no correlation between the presence of an X-ray detected intra-group medium and molecular gas in the dominant galaxy, but find that the HI-richest galaxies are located in X-ray faint groups. Morphological data from the literature suggests the cold gas component most commonly takes the form of a disk, but many systems show evidence of galaxy-galaxy interactions, indicating that they may have acquired their gas through stripping or mergers. We provide improved molecular gas mass estimates for two galaxies previously identified as being in the centres of cooling flows, NGC 4636 and NGC5846, and find that they are relatively molecular gas poor compared to our other detected systems.
