- ID:
- ivo://CDS.VizieR/J/A+A/615/A103
- Title:
- CORNISH project. III. UCHII region catalogue
- Short Name:
- J/A+A/615/A103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A catalogue of 239 ultra-compact HII regions (UCHIIs) found in the CORNISH survey at 5GHz and 1.5-arcsec resolution in the region 10{deg}<l<65{deg}, |b|<1{deg} is presented. This is the largest complete and well-selected sample of UCHIIs to date and provides the opportunity to explore the global and individual properties of this key state in massive star formation at multiple wavelengths. The nature of the candidates was validated, based on observational properties and calculated spectral indices, and the analysis is presented in this work. The physical sizes, luminosities and other physical properties were computed by utilising literature distances or calculating the distances whenever a value was not available. The near- and mid-infrared extended source fluxes were measured and the extinctions towards the UCHIIs were computed. The new results were combined with available data at longer wavelengths and the spectral energy distributions (SEDs) were reconstructed for 177 UCHIIs. The bolometric luminosities obtained from SED fitting are presented. By comparing the radio flux densities to previous observational epochs, we find about 5% of the sources appear to be time variable. This first high-resolution area survey of the Galactic plane shows that the total number of UCHIIs in the Galaxy is ~750 - a factor of 3-4 fewer than found in previous large area radio surveys. It will form the basis for future tests of models of massive star formation.
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- ID:
- ivo://CDS.VizieR/J/ApJS/205/1
- Title:
- CORNISH project. II. Source catalog
- Short Name:
- J/ApJS/205/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CORNISH (Co-Ordinated Radio 'N' Infrared Survey for High-mass star formation) project is the highest resolution radio continuum survey of the Galactic plane to date. It is the 5GHz radio continuum part of a series of multi-wavelength surveys that focus on the northern GLIMPSE region (10{deg}<l<65{deg}), observed by the Spitzer satellite in the mid-infrared. Observations with the Very Large Array in B and BnA configurations have yielded a 1.5" resolution Stokes I map with a root mean square noise level better than 0.4mJy/beam. Here we describe the data-processing methods and data characteristics, and present a new, uniform catalog of compact radio emission. This includes an implementation of automatic deconvolution that provides much more reliable imaging than standard CLEANing. A rigorous investigation of the noise characteristics and reliability of source detection has been carried out. We show that the survey is optimized to detect emission on size scales up to 14" and for unresolved sources the catalog is more than 90% complete at a flux density of 3.9mJy. We have detected 3062 sources above a 7{sigma} detection limit and present their ensemble properties. The catalog is highly reliable away from regions containing poorly sampled extended emission, which comprise less than 2% of the survey area. Imaging problems have been mitigated by down-weighting the shortest spacings and potential artifacts flagged via a rigorous manual inspection with reference to the Spitzer infrared data. We present images of the most common source types found: HII regions, planetary nebulae, and radio galaxies.
- ID:
- ivo://CDS.VizieR/J/MNRAS/480/2423
- Title:
- CORNISH project IV. Radio-selected galactic PN
- Short Name:
- J/MNRAS/480/2423
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new radio-selected sample of PNe from the CORNISH survey. We find 90 new PNe, of which 12 are newly discovered and 78 are newly classified as PN. A further 47 previously suspected PNe are confirmed as such from the analysis presented here and 24 known PNe are detected. Eight sources are classified as possible PNe or other source types.
- ID:
- ivo://CDS.VizieR/J/ApJ/710/L58
- Title:
- Coronal type II radio bursts in 2002
- Short Name:
- J/ApJ/710/L58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Major space weather events such as solar flares and coronal mass ejections are usually accompanied by solar radio bursts, which can potentially be used for real-time space weather forecasts. Type II radio bursts are produced near the local plasma frequency and its harmonic by fast electrons accelerated by a shock wave moving through the corona and solar wind with a typical speed of ~1000km/s. The coronal bursts have dynamic spectra with frequency gradually falling with time and durations of several minutes. This Letter presents a new method developed to detect type II coronal radio bursts automatically and describes its implementation in an extended Automated Radio Burst Identification System (ARBIS 2). Preliminary tests of the method with spectra obtained in 2002 show that the performance of the current implementation is quite high, ~80%, while the probability of false positives is reasonably low, with one false positive per 100-200hr for high solar activity and less than one false event per 10000hr for low solar activity periods. The first automatically detected coronal type II radio burst is also presented.
- ID:
- ivo://CDS.VizieR/J/MNRAS/414/2005
- Title:
- Cosmic flows observations
- Short Name:
- J/MNRAS/414/2005
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The neutral hydrogen properties of 1822 galaxies are being studied with the Green Bank 100-m and the Parkes 64-m telescopes as part of the 'Cosmic Flows' programme. Observed parameters include systemic velocities, profile linewidths and integrated fluxes. The linewidth information can be combined with the optical and infrared photometry to obtain distances. The 1822 HI observations complement an inventory of archives.
- ID:
- ivo://CDS.VizieR/J/A+A/589/A60
- Title:
- CO, SO and H_2_CO images of AB Aur
- Short Name:
- J/A+A/589/A60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Transitional disks are structures of dust and gas around young stars with large inner cavities in which planet formation may occur. Lopsided dust distributions are observed in the dust continuum emission at millimeter wavelengths. These asymmetrical structures can be explained as being the result of an enhanced gas density vortex where the dust is trapped, potentially promoting the rapid growth to the planetesimal scale. AB Aur hosts a transitional disk with a clear horseshoe morphology which strongly suggests the presence of a dust trap. Our goal is to investigate its formation and the possible effects on the gas chemistry. We used the NOrthern Extended Millimeter Array (NOEMA) interferometer to image the 1mm continuum dust emission and the ^13^CO J=2->1, C^18^O J=2->1, SO J=5_6_->4_5_, and H_2_CO J=3_03_->2_02_. rotational lines.
- ID:
- ivo://CDS.VizieR/J/ApJS/196/18
- Title:
- CO survey of galactic molecular clouds. II.
- Short Name:
- J/ApJS/196/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present fully sampled 38" resolution maps of the CO and ^13^CO J=2-1 lines in the molecular clouds toward the HII region complex W3. The maps cover a 2.0{deg}x1.67{deg} section of the galactic plane and span -70 to -20km/s (LSR) in velocity with a resolution of ~1.3km/s. The velocity range of the images includes all the gas in the Perseus spiral arm. We also present maps of CO J=3-2 emission for a 0.5{deg}x0.33{deg} area containing the HII regions W3 Main and W3(OH). The J=3-2 maps have velocity resolution of 0.87km/s and 24" angular resolution. Color figures display the peak line brightness temperature, the velocity-integrated intensity, and velocity channel maps for all three lines, and also the (CO/^13^CO) J=2-1 line intensity ratios as a function of velocity. The line intensity image cubes are made available in standard FITS format as electronically readable files. We compare our molecular line maps with the 1.1mm continuum image from the BOLOCAM Galactic Plane Survey (BGPS). From our ^13^CO image cube, we derive kinematic information for the 65 BGPS sources in the mapped field, in the form of Gaussian component fits.
- ID:
- ivo://CDS.VizieR/J/ApJS/209/39
- Title:
- CO survey of molecular clouds. III. Serpens
- Short Name:
- J/ApJS/209/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We mapped ^12^CO and ^13^CO J=2-1 emission over 1.04deg^2^ of the Serpens molecular cloud with 38" spatial and 0.3km/s spectral resolution using the Arizona Radio Observatory Heinrich Hertz Submillimeter Telescope. Our maps resolve kinematic properties for the entire Serpens cloud. We also compare our velocity moment maps with known positions of young stellar objects (YSOs) and 1.1 mm continuum emission. We find that ^12^CO is self-absorbed and ^13^CO is optically thick in the Serpens core. Outside of the Serpens core, gas appears in filamentary structures having LSR velocities which are blueshifted by up to 2km/s relative to the 8km/s systemic velocity of the Serpens cloud. We show that the known Class I, flat, and Class II YSOs in the Serpens core most likely formed at the same spatial location and have since drifted apart. The spatial and velocity structure of the ^12^CO line ratios implies that a detailed three-dimensional radiative transfer model of the cloud will be necessary for full interpretation of our spectral data. The "starless cores" region of the cloud is likely to be the next site of star formation in Serpens.
- ID:
- ivo://CDS.VizieR/J/ApJS/214/7
- Title:
- CO survey of molecular clouds. IV. NGC 1333
- Short Name:
- J/ApJS/214/7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We mapped the NGC 1333 section of the Perseus Molecular Cloud in the J=2-1 emission lines of ^12^CO and ^13^CO over a 50'x60' region (3.4x4.1pc at the cloud distance of 235pc), using the Arizona Radio Observatory Heinrich Hertz Submillimeter Telescope. The angular resolution is 38" (0.04pc) and velocity resolution is 0.3km/s. We compare our velocity moment maps with known positions of young stellar objects (YSOs) and (sub)millimeter dust continuum emission. The CO emission is brightest at the center of the cluster of YSOs, but is detected over the full extent of the mapped region at >=10xrms. The morphology of the CO channel maps shows a kinematically complex structure, with many elongated features extending from the YSO cluster outward by ~1pc. One notable feature appears as a narrow serpentine structure that curves and doubles back, with a total length of ~3pc. The ^13^CO velocity channel maps show evidence for many low-density cavities surrounded by partial shell-like structures, consistent with previous studies. Maps of the velocity moments show localized effects of bipolar outflows from embedded YSOs, as well as a large-scale velocity gradient around the central core of YSOs, suggestive of large-scale turbulent cloud motions determining the location of current star formation. The CO/^13^CO intensity ratios show the distribution of the CO opacity, which exhibits a complex kinematic structure. Identified YSOs are located mainly at the positions of greatest CO opacity.
- ID:
- ivo://CDS.VizieR/J/PASJ/56/313
- Title:
- 13CO survey of Mon & CMa molecular clouds
- Short Name:
- J/PASJ/56/313
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Through a large-scale 13^CO (J=1-0) survey toward a region in Monoceros and Canis Major, we have identified in total 115 clouds.