- ID:
- ivo://CDS.VizieR/J/MNRAS/427/1830
- Title:
- 20cm survey of the AKARI SEP (ATCA-ADFS)
- Short Name:
- J/MNRAS/427/1830
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of a deep radio survey at 20cm wavelength are reported for a region containing the AKARI Deep Field South (ADF-S) near the South Ecliptic Pole (SEP), using the Australia Telescope Compact Array (ATCA). The survey (hereafter referred to as the ATCA-ADFS survey) has 1{sigma} detection limits ranging from 18.7 to 50{mu}Jy/beam over an area of ~1.1deg^2^, and ~ 2.5deg^2^ to lower sensitivity. The observations, data reduction and source count analysis are presented along with a description of the overall scientific objectives, and a catalogue containing 530 radio sources detected with a resolution of 6.2x4.9arcsec.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/690/837
- Title:
- CN and CO observations toward AGB stars
- Short Name:
- J/ApJ/690/837
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A survey of the ^12^C/^13^C ratio toward circumstellar envelopes has been conducted at millimeter wavelengths using the facilities of the Arizona Radio Observatory (ARO). The ratios were obtained for a sample of 18 local C- and O-rich asymptotic giant branch and supergiant stars from observations of the ^12^C and ^13^C isotopologues of CO and CN, respectively. The J=1->0 transitions of both molecules were observed at {lambda}=3mm using the ARO 12m telescope, while the J=2->1 lines of the two species were measured using the ARO Sub-Millimeter Telescope (SMT) at {lambda}=1mm. The ^12^C/^13^C ratios were determined from the CO data by modeling both transitions simultaneously with a circumstellar radiative transfer code, which can account for the high opacities present in the emission from this species. In the case of CN, the hyperfine structure was used to evaluate opacity effects. Ratios obtained independently from CO and CN are in good agreement.
- ID:
- ivo://CDS.VizieR/J/A+A/544/A69
- Title:
- CN(1-0) Zeeman observations of NGC 2264-C
- Short Name:
- J/A+A/544/A69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From an observational point of view, the role of magnetic fields in star formation remains unclear, and two main theoretical scenarios have been proposed so far to regulate the star-formation processes. The first model assumes that turbulence in star-forming clumps plays a crucial role, and especially that protostellar outflow-driven turbulence is crucial to support cluster-forming clumps; while the second scenario is based on the consideration of a magnetically-supported clump. Previous studies of the NGC 2264-C protocluster indicate that, in addition to thermal pressure, some extra support might effectively act against the gravitational collapse of this cluster- forming clump. We previously showed that this extra support is not due to the numerous protostellar outflows, nor the enhanced turbulence in this protocluster. Here we present the results of the first polarimetric campaign dedicated to quantifying the magnetic support at work in the NGC 2264-C clump. Our Zeeman observations of the CN(1-0) hyperfine lines provide an upper limit to the magnetic field strength Blos<0.6 mG in the protocluster (projected along the line of sight). While these results do not provide sufficiently tight constraints to fully quantify the magnetic support at work in NGC 2264-C, they suggest that, within the uncertainties, the core could be either magnetically super or sub-critical, with the former being more likely.
294. Coalsack CO maps
- ID:
- ivo://CDS.VizieR/J/A+A/533/A17
- Title:
- Coalsack CO maps
- Short Name:
- J/A+A/533/A17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The large Coalsack dark cloud is one of the most prominent southern starless clouds, which is even visible to the naked eye. Furthermore, it is one of the rare molecular clouds without clear signs of star formation. We investigate the dynamical properties of the gas within the Coalsack. The two highest extinction regions were mapped with the APEX telescope in ^13^CO(2-1) comprising a region of ~1 square degree.
- ID:
- ivo://CDS.VizieR/J/A+A/475/559
- Title:
- 12CO(1-0) and 12CO(2-1) maps of EP Aqr
- Short Name:
- J/A+A/475/559
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CO rotational lines are frequently used to trace the outflows from AGB stars. Some profiles are composite, with a narrow component super-imposed on a broader one. These profiles have been interpreted in different ways, calling for episodic mass loss, a bipolar flow, or a circumstellar disk.
- ID:
- ivo://CDS.VizieR/J/A+AS/126/3
- Title:
- CO and HI in interacting galaxies
- Short Name:
- J/A+AS/126/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using SEST, the Parkes antenna and the Australia Telescope Compact Array, we have made a survey of the ^12^CO(1-0) and HI emission of an optically-selected sample of =~60 southern interacting and merging galaxies. In this paper we present the data and determine global masses of neutral gas (in molecular and atomic form) for the observed galaxies. We have detected HI in 26 systems and found that these galaxies have less than 15% of their gas in molecular form.
- ID:
- ivo://CDS.VizieR/J/A+A/554/A55
- Title:
- C^18^O(1-0) and N_2_H^+^(1-0) in L1495/B213
- Short Name:
- J/A+A/554/A55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Core condensation is a critical step in the star-formation process, but it is still poorly characterized observationally. We have studied the 10pc-long L1495/B213 complex in Taurus to investigate how dense cores have condensed out of the lower density cloud material. We observed L1495/B213 in C^18^O(1-0), N_2_H^+^(1-0), and SO(J_N_=3_2_-2_1_) with the 14m FCRAO telescope, and complemented the data with dust continuum observations using APEX (870um) and IRAM 30m (1200um).
- ID:
- ivo://CDS.VizieR/J/PASJ/62/557
- Title:
- CO clouds in the Galactic Center from NANTEN
- Short Name:
- J/PASJ/62/557
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to better understand molecular clouds and their properties toward the Galactic center region, we have analyzed the NANTEN database of ^12^CO (J=1-0) and ^13^CO (J=1-0) to search for associations with candidates for young high-mass star-forming regions, such as IRAS point sources, radio continuum sources, recombination line sources, maser line sources, and other molecular line sources. We have also compared the data with TeV gamma-ray sources. The analyzed region covers -12{deg}<=l<=12{deg} and -1.5{deg}<=b<=1.5{deg} for ^12^CO, and -6{deg}<=l<=8{deg} and -1{deg}<=b<=1{deg} for ^13^CO. As a result, we identified 167 IRAS point sources, 73 recombination line sources, 58 maser sources, 107 radio continuum sources, and 77 molecular line sources associated with 169 positions with the CO emission.
- ID:
- ivo://CDS.VizieR/J/ApJ/686/384
- Title:
- ^12^CO, ^13^CO, C^18^O survey of IRDCs
- Short Name:
- J/ApJ/686/384
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Infrared dark clouds (IRDCs) are extinction features against the Galactic infrared background, mainly in the mid-infrared band. Recently they were proposed to be potential sites of massive star formation. In this work we have made a ^12^CO, ^13^CO, and C^18^O (J=1->0) survey of 61 IRDCs, 52 of which are in the first Galactic quadrant, selected from a catalog given by Simon and coworkers (2006, Cat. J/ApJ/639/227), while the others are in the outer Galaxy, selected by visually inspecting the Midcourse Space Experiment (MSX) images. Detection rates in the three CO lines are 90%, 71%, and 62%, respectively. The distribution of IRDCs in the first Galactic quadrant is consistent with the 5kpc molecular ring picture, while a slight trace of a spiral pattern is also noticeable, and needs to be further examined. The IRDCs have a typical excitation temperature of 10K and typical column density of several 10^22^cm^-2^. Their typical physical size is estimated to be several parsecs using angular sizes from the Simon catalog.
- ID:
- ivo://CDS.VizieR/J/ApJ/720/259
- Title:
- CO column densities in dark clouds
- Short Name:
- J/ApJ/720/259
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Data from the Five College Radio Astronomy Observatory CO Mapping Survey of the Taurus molecular cloud are combined with extinction data for a sample of 292 background field stars to investigate the uptake of CO from the gas to icy grain mantles on dust within the cloud. On the assumption that the reservoir of CO in the ices is represented well by the combined abundances of solid CO and solid CO_2_ (which forms by oxidation of CO on the dust), we find that the total column density (gas+solid) correlates tightly with visual extinction (A_V_) over the range 5mag<A_V_<30mag, i.e., up to the highest extinctions covered by our sample. The mean depletion of gas-phase CO, expressed as {delta}(CO)=N(CO)_ice_/N(CO)_total_, increases monotonically from negligible levels for A_V_<~5 to ~0.3 at A_V_=10 and ~0.6 at A_V_=30. As these results refer to line-of-sight averages, they must be considered lower limits to the actual depletion at loci deep within the cloud, which may approach unity. We show that it is plausible for such high levels of depletion to be reached in dense cores on timescales ~0.6Myr, comparable with their expected lifetimes. Dispersal of cores during star formation may be effective in maintaining observable levels of gaseous CO on the longer timescales estimated for the age of the cloud.