- 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.
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- 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.
- ID:
- ivo://CDS.VizieR/J/ApJS/252/20
- Title:
- CO survey of the CMa OB1 complex
- Short Name:
- J/ApJS/252/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the Purple Mountain Observatory 13.7m millimeter telescope at Delingha in China, we have conducted a large-scale simultaneous survey of ^12^CO, ^13^CO, and C^18^O (J=1-0) toward the CMa OB1 complex with a sky coverage of 16.5deg^2^ (221.5{deg}<=l<=227{deg}, -2.5{deg}<=b<=0.5{deg}). Emission from the CMa OB1 complex is found in the range 7km/s<=V_LSR_<=25km/s. The large-scale structure, physical properties, and chemical abundances of the molecular clouds are presented. A total of 83 C^18^O molecular clumps are identified with the GaussClumps algorithm within the mapped region. We find that 94% of these C18O molecular clumps are gravitationally bound. The relationship between their size and mass indicates that none of the C^18^O clumps has the potential to form high-mass stars. Using a semiautomatic IDL algorithm, we newly discover 85 CO outflow candidates in the mapped area, including 23 bipolar outflow candidates. Additionally, a comparative study reveals evidence for a significant variety of physical properties, evolutionary stages, and levels of star formation activity in different subregions of the CMa OB1 complex.
- ID:
- ivo://CDS.VizieR/J/A+A/570/A1
- Title:
- Cygnus-X CO and SiO outflows datacubes
- Short Name:
- J/A+A/570/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from a PdBI study of six massive dense cores in Cygnus-X, with CO (2-1) and SiO (2-1) emission. We studied the outflows of the individual protostars with CO (Duarte-Cabral et al., 2013A&A...558A.125D), and investigated the interstellar shocks responsible for the SiO emission (in Duarte-Cabral et al. 2014A&A...570A...1D).
- ID:
- ivo://CDS.VizieR/J/ApJ/725/2232
- Title:
- Deep NIR survey of the Pipe Nebula. II.
- Short Name:
- J/ApJ/725/2232
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new set of high-resolution dust extinction maps of the nearby and essentially starless Pipe Nebula molecular cloud. The maps were constructed from a concerted deep near-infrared imaging survey with the ESO-VLT, ESO-NTT, CAHA 3.5m telescopes, and 2MASS data. The new maps have a resolution three times higher than the previous extinction map of this cloud by Lombardi et al. (2006A&A...454..781L) and are able to resolve structures down to 2600AU. We detect 244 significant extinction peaks across the cloud. These peaks have masses between 0.1 and 18.4M_{sun}_, diameters between 1.2 and 5.7x10^4^AU (0.06 and 0.28pc), and mean densities of about 10^4^cm^-3^, all in good agreement with previous results. From the analysis of the mean surface density of companions we find a well-defined scale near 1.4x10^4^AU below which we detect a significant decrease in structure of the cloud. This scale is smaller than the Jeans length calculated from the mean density of the peaks. The surface density of peaks is not uniform but instead it displays clustering. Extinction peaks in the Pipe Nebula appear to have a spatial distribution similar to the stars in Taurus, suggesting that the spatial distribution of stars evolves directly from the primordial spatial distribution of high-density material.
- ID:
- ivo://CDS.VizieR/J/A+A/619/A52
- Title:
- Dense cores and YSOs in Lupus complex
- Short Name:
- J/A+A/619/A52
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the catalogue of the dense cores and YSOs/protostars of the Lupus I, Lupus III, and Lupus IV molecular clouds. Sources were extracted from the far-infrared photometric maps at 70, 160, 250, 350 and 500um acquired with the Spectral and Photometric Imaging Receiver (SPIRE) and the Photodetector Array Camera and Spectrometer (PACS) instruments onboard the Herschel Space Observatory, within the Herschel Gould Belt Survey project. A total of 532 dense cores, out of which 103 are presumably prestellar in nature, and 38 YSOs/protostars have been detected in the three clouds. The physical properties of the objects were derived by fitting their spectral energy distributions. Almost all the prestellar cores are associated with filaments against only about one third of the unbound cores and YSOs/ protostars. Prestellar core candidates are found even in filaments that are on average thermally sub-critical and over a background column density lower than that measured in other star forming regions so far. The core mass function of the prestellar cores peaks between 0.2 and 0.3 solar masses and it is compatible with the log-normal shape found in other regions. Herschel data reveal several, previously undetected, protostars and new candidates of Class 0 and Class II with transitional disks. We estimate the evolutionary status of the YSOs/protostars using two independent indicators: the {alpha} index and the fitting of the spectral energy distribution from near- to far-infrared wavelengths. For 70% of the objects, the evolutionary stages derived with the two methods are in agreement.
- ID:
- ivo://CDS.VizieR/J/ApJ/710/1247
- Title:
- Dense cores in Gould Belt clouds
- Short Name:
- J/ApJ/710/1247
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using data from the SCUBA Legacy Catalogue (850um) and Spitzer Space Telescope (3.6-70um), we explore dense cores in the Ophiuchus, Taurus, Perseus, Serpens, and Orion molecular clouds. We develop a new method to discriminate submillimeter cores found by Submillimeter Common-User Bolometer Array (SCUBA) as starless or protostellar, using point source photometry from Spitzer wide field surveys. First, we identify infrared sources with red colors associated with embedded young stellar objects (YSOs). Second, we compare the positions of these YSO candidates to our submillimeter cores. With these identifications, we construct new, self-consistent starless and protostellar core mass functions (CMFs) for the five clouds. We find best-fit slopes to the high-mass end of the CMFs of -1.26+/-0.20, -1.22+/-0.06, -0.95+/-0.20, and -1.67+/-0.72 for Ophiuchus, Taurus, Perseus, and Orion, respectively.
- ID:
- ivo://CDS.VizieR/J/A+A/462/L17
- Title:
- Dense cores in interstellar molecular clouds
- Short Name:
- J/A+A/462/L17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stars form in the cold dense cores of interstellar molecular clouds and the detailed knowledge of the spectrum of masses of such cores is clearly a key for the understanding of the origin of the IMF. To date, observations have presented somewhat contradictory evidence relating to this issue. In this paper we propose to derive the mass function of a complete sample of dense molecular cores in a single cloud employing a robust method that uses uses extinction of background starlight to measure core masses and enables the reliable extension of such measurements to lower masses than previously possible. We use a map of near-infrared extinction in the nearby Pipe dark cloud to identify the population of dense cores in the cloud and measure their masses.
