- ID:
- ivo://CDS.VizieR/J/ApJ/860/172
- Title:
- Cloud-scale molecular gas properties in 15 galaxies
- Short Name:
- J/ApJ/860/172
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We measure the velocity dispersion, {sigma}, and surface density, {Sigma}, of the molecular gas in nearby galaxies from CO spectral line cubes with spatial resolution 45-120pc, matched to the size of individual giant molecular clouds. Combining 11 galaxies from the PHANGS-ALMA survey with four targets from the literature, we characterize ~30000 independent sightlines where CO is detected at good significance. {Sigma} and {sigma} show a strong positive correlation, with the best-fit power-law slope close to the expected value for resolved, self-gravitating clouds. This indicates only a weak variation in the virial parameter {alpha}_vir_{propto}{sigma}^2^/{Sigma}, which is ~1.5-3.0 for most galaxies. We do, however, observe enormous variation in the internal turbulent pressure P_turb_{propto}{Sigma}{sigma}^2^, which spans ~5dex across our sample. We find {Sigma}, {sigma}, and P_turb_ to be systematically larger in more massive galaxies. The same quantities appear enhanced in the central kiloparsec of strongly barred galaxies relative to their disks. Based on sensitive maps of M31 and M33, the slope of the {sigma}-{Sigma} relation flattens at {Sigma}<~10M_{sun}_/pc^2^, leading to high {sigma} for a given {Sigma} and high apparent {alpha}_vir_. This echoes results found in the Milky Way and likely originates from a combination of lower beam-filling factors and a stronger influence of local environment on the dynamical state of molecular gas in the low-density regime.
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- ID:
- ivo://CDS.VizieR/J/A+A/601/A124
- Title:
- Clouds in SEDIGISM science demonstration field
- Short Name:
- J/A+A/601/A124
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The origin and life-cycle of molecular clouds are still poorly constrained, despite their importance for understanding the evolution of the interstellar medium. Many large-scale surveys of the Galactic plane have been conducted recently, allowing for rapid progress in this field. Nevertheless, a sub-arcminute resolution global view of the large-scale distribution of molecular gas, from the diffuse medium to dense clouds and clumps, and of their relationship to the spiral structure, is still missing. We have carried out a systematic, homogeneous, spectroscopic survey of the inner Galactic plane, in order to complement the many continuum Galactic surveys available with crucial distance and gas-kinematic information. Our aim is to combine this data set with recent infrared to sub-millimetre surveys at similar angular resolutions. The SEDIGISM survey covers 78deg^2^ of the inner Galaxy (-60{deg}<l<+18{deg}, |b|<0.5{deg}) in the J=2-1 rotational transition of ^13^CO. This isotopologue of CO is less abundant than ^12^CO by factors up to 100. Therefore, its emission has low to moderate optical depths, and higher critical density, making it an ideal tracer of the cold, dense interstellar medium. The data have been observed with the SHFI single-pixel instrument at APEX. The observational setup covers the ^13^CO(2-1) and C^18^O(2-1) lines, plus several transitions from other molecules. The observations have been completed. Data reduction is in progress and the final data products will be made available in the near future. Here we give a detailed description of the survey and the dedicated data reduction pipeline. To illustrate the scientific potential of this survey, preliminary results based on a science demonstration field covering -20{deg}<l<-18.5{deg} are presented. Analysis of the ^13^CO(2-1) data in this field reveals compact clumps, diffuse clouds, and filamentary structures at a range of heliocentric distances. By combining our data with data in the (1-0) transition of CO isotopologues from the ThrUMMS survey, we are able to compute a 3D realization of the excitation temperature and optical depth in the interstellar medium. Ultimately, this survey will provide a detailed, global view of the inner Galactic interstellar medium at an unprecedented angular resolution of ~30".
- ID:
- ivo://CDS.VizieR/J/AJ/126/2644
- Title:
- CL 0024+1654 UBVI photometry
- Short Name:
- J/AJ/126/2644
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Wide-field (20x20arcmin^2^) UBVI images of intermediate-redshift (z=0.39), Butcher-Oemler cluster CL0024+1654 are being distributed. These data probe the rest-frame mid-UV properties over a much larger area than previous studies of CL0024+1654. These images were obtained with the 0.9m telescope at the NOAO Kitt Peak National Observatory in 1991-1992. The resolution is 0.68 arcsec/pix, and the field-of-view is 20arcmin^2^. The standard KPNO Harris filter set was used. We are distributing the individual U, B, V and I frames, as well as the combined U+B+V+I image. Using these data, SExtractor was used to construct a multi-color catalog of approximately 6000 objects in this field. We present both isophotal and aperture photometry in the catalog to be complete. We cross-matched the objects in our catalog with three other CL0024 datasets, and list the matching results in the distributed catalog. Our catalog includes the cross-references to data from Czoske et al., 2001, Cat. <J/A+A/372/391>; from Smail et al., 1997, Cat. <J/ApJS/110/213>; and from Dressler et al., 1999, Cat. <J/ApJS/122/51>.
- ID:
- ivo://CDS.VizieR/J/ApJ/703/736
- Title:
- Clump properties in the LMC 30 Dor region
- Short Name:
- J/ApJ/703/736
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a complete ^12^CO(J=1-0) map of the prominent molecular ridge in the Large Magellanic Cloud (LMC) obtained with the 22m ATNF Mopra Telescope. The region stretches southward by ~2{deg} (or 1.7kpc) from 30 Doradus, the most vigorous star-forming region in the Local Group. The location of this molecular ridge is unique insofar as it allows us to study the properties of molecular gas as a function of the ambient radiation field in a low-metallicity environment. The mass spectrum and the scaling relations between the properties of the CO clumps in the molecular ridge are similar, but not identical, to those that have been established for Galactic molecular clouds.
- ID:
- ivo://CDS.VizieR/J/ApJ/625/891
- Title:
- Clumps in NGC 7538 at 450 and 850{mu}m
- Short Name:
- J/ApJ/625/891
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present submillimeter continuum maps at 450 and 850{mu}m of a 12'x8' region of the NGC 7538 high-mass star-forming region, made using the Submillimeter Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope. We used an automated clump-finding algorithm to identify 67 clumps in the 450{mu}m image and 77 in the 850{mu}m image.
- ID:
- ivo://CDS.VizieR/J/AJ/136/2083
- Title:
- Clumps in NGC 6334 from 450/850um observations
- Short Name:
- J/AJ/136/2083
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NGC 6334 is a galactic star-forming region in Scorpius, heavily obscured by intervening dust. The region consists of several major sites of star formation known previously from far-infrared (IR) and radio-wavelength observations. We present images of NGC 6334 obtained at wavelengths of 850 and 450um with the Submillimeter Common-User Bolometric Array at the James Clerk Maxwell Telescope. These data highlight the distribution of dense cold dust, a particularly striking feature of which is a narrow ridge of emission passing between most of the star-forming centers. We use a clump-finding technique to quantify the distribution of dust emission throughout the region, and we obtain estimates of the sizes, masses, and temperatures of the clump ensemble under simple assumptions.
- ID:
- ivo://CDS.VizieR/J/A+A/534/A131
- Title:
- Clumps in the giant molecular cloud G345.5+1.0
- Short Name:
- J/A+A/534/A131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Massive condensations in giant molecular clouds (GMCs) are linked to the formation of high mass stars, which are the principal source of heavy elements and UV radiation, playing an important role in the evolution of galaxies. We attemp to make a complete census of massive-star formation within all of GMC G345.5+1.0. This cloud is located one degree above the Galactic plane and at 1.8kpc from the Sun, thus there is little superposition of dust along the line-of-sight, minimizing confusion effects in identifying individual clumps. GMC G345.5+1.0 is located approximately between 344.5{deg} and 346.5{deg} in Galactic longitude, and between 0.2{deg} and 2.0{deg} in Galactic latitude.
- ID:
- ivo://CDS.VizieR/J/A+A/531/A26
- Title:
- Clumps in W31 from CO and 875um observations
- Short Name:
- J/A+A/531/A26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-mass star formation has been a very active field over the past decade; however, most studies have targeted regions of luminosities between 10^4^ and 10^5^L_{sun}_. In contrast to that, the highest mass stars reside in clusters exceeding 10^5^ or even 10^6^L_{sun}_. We want to study the physical conditions associated with the formation of the highest mass stars. To do this, we selected the W31 star-forming complex with a total luminosity of ~6x10^6^L_{sun}_ (comprised of at least two subregions) for a multiwavelength spectral line and continuum study covering wavelengths from the near- and midinfrared via (sub)mm wavelength observations to radio data in the cm regime.
- ID:
- ivo://CDS.VizieR/J/ApJ/853/108
- Title:
- Clumpy galaxies in CANDELS. II. 0.5<=z<3.0
- Short Name:
- J/ApJ/853/108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Studying giant star-forming clumps in distant galaxies is important to understand galaxy formation and evolution. At present, however, observers and theorists have not reached a consensus on whether the observed "clumps" in distant galaxies are the same phenomenon that is seen in simulations. In this paper, as a step to establish a benchmark of direct comparisons between observations and theories, we publish a sample of clumps constructed to represent the commonly observed "clumps" in the literature. This sample contains 3193 clumps detected from 1270 galaxies at 0.5<=z<3.0. The clumps are detected from rest-frame UV images, as described in our previous paper. Their physical properties (e.g., rest-frame color, stellar mass (M*), star formation rate (SFR), age, and dust extinction) are measured by fitting the spectral energy distribution (SED) to synthetic stellar population models. We carefully test the procedures of measuring clump properties, especially the method of subtracting background fluxes from the diffuse component of galaxies. With our fiducial background subtraction, we find a radial clump U-V color variation, where clumps close to galactic centers are redder than those in outskirts. The slope of the color gradient (clump color as a function of their galactocentric distance scaled by the semimajor axis of galaxies) changes with redshift and M* of the host galaxies: at a fixed M*, the slope becomes steeper toward low redshift, and at a fixed redshift, it becomes slightly steeper with M*. Based on our SED fitting, this observed color gradient can be explained by a combination of a negative age gradient, a negative E(B-V) gradient, and a positive specific SFR gradient of the clumps. We also find that the color gradients of clumps are steeper than those of intra-clump regions. Correspondingly, the radial gradients of the derived physical properties of clumps are different from those of the diffuse component or intra-clump regions.
- ID:
- ivo://CDS.VizieR/J/AZh/74/63
- Title:
- Cluster analysis of pulsar parameters
- Short Name:
- J/AZh/74/63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalogue of pulsars with several calculated data is used by the cluster analysis for the division of pulsars into groups. Pulsars with periods P>1s and P<0.1s form two separate classes; the short-period objects, in turn, divide into two groups. One of these consist of young pulsars that form in the galactic plane or in globular clusters, while the other group consist of spun-up pulsars.