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1251. Planck cold clumps survey in the Orion complex
ID:
ivo://CDS.VizieR/J/ApJS/202/4
Title:
Planck cold clumps survey in the Orion complex
Short Name:
J/ApJS/202/4
Date:
21 Oct 2021
Publisher:
CDS
Description:
A mapping survey of 51 Planck cold clumps projected on the Orion complex was performed with J=1-0 lines of ^12^CO and ^13^CO with the 13.7m telescope at the Purple Mountain Observatory. The mean column densities of the Planck gas clumps range from 0.5 to 9.5x10^21^cm^-2^, with an average value of (2.9+/-1.9)x10^21^cm^-2^. The mean excitation temperatures of these clumps range from 7.4 to 21.1K, with an average value of 12.1+/-3.0K and the average three-dimensional velocity dispersion {sigma}_3D_ in these molecular clumps is 0.66+/-0.24km/s. The H2 column density of the molecular clumps calculated from molecular lines correlates with the aperture flux at 857GHz of the dust emission. By analyzing the distributions of the physical parameters, we suggest that turbulent flows can shape the clump structure and dominate their density distribution on large scales, but not function on small scales due to local fluctuations. Eighty-two dense cores are identified in the molecular clumps. The dense cores have an average radius and local thermal equilibrium (LTE) mass of 0.34+/-0.14pc and 38^+5^_-30_M_{sun}_, respectively. The structures of low column density cores are more affected by turbulence, while the structures of high column density cores are more affected by other factors, especially by gravity.
1252. Planck cold dust clumps CO survey
ID:
ivo://CDS.VizieR/J/ApJ/756/76
Title:
Planck cold dust clumps CO survey
Short Name:
J/ApJ/756/76
Date:
21 Oct 2021
Publisher:
CDS
Description:
A survey toward 674 Planck cold clumps of the Early Cold Core Catalogue (ECC) in the J=1-0 transitions of ^12^CO, ^13^CO, and C^18^O has been carried out using the Purple Mountain Observatory 13.7m telescope. Six hundred seventy-three clumps were detected with ^12^CO and ^13^CO emission, and 68% of the sample has C^18^O emission. Additional velocity components were also identified. A close consistency of the three line peak velocities was revealed for the first time. Kinematic distances are given for all the velocity components, and half of the clumps are located within 0.5 and 1.5kpc. Excitation temperatures range from 4 to 27K, slightly larger than those of T_d_. Line width analysis shows that the majority of ECC clumps are low-mass clumps. Ten clumps were mapped. Twelve velocity components and 22 cores were obtained. Their morphologies include extended diffuse, dense, isolated, cometary, and filament, of which the last is the majority. Twenty cores are starless, and only seven cores seem to be in a gravitationally bound state. Planck cold clumps are the most quiescent among the samples of weak red IRAS, infrared dark clouds, UC HII candidates, extended green objects, and methanol maser sources, suggesting that Planck cold clumps have expanded the horizon of cold astronomy.
1253. Planck ERCSC sources with 100 GHz flux excess
ID:
ivo://CDS.VizieR/J/MNRAS/458/3619
Title:
Planck ERCSC sources with 100 GHz flux excess
Short Name:
J/MNRAS/458/3619
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Planck Early Release Compact Source Catalogue (ERCSC) includes nine lists of highly reliable sources, individually extracted at each of the nine Planck frequency channels. To facilitate the study of the Planck sources, especially their spectral behaviour across the radio/infrared frequencies, we provide a 'bandmerged' catalogue of the ERCSC sources. This catalogue consists of 15191 entries, with 79 sources detected in all nine frequency channels of Planck and 6818 sources detected in only one channel. We describe the bandmerging algorithm, including the various steps used to disentangle sources in confused regions. The multifrequency matching allows us to develop spectral energy distributions of sources between 30 and 857GHz, in particular across the 100GHz band, where the energetically important CO J=1->0 line enters the Planck bandpass. We find ~3{sigma}-5{sigma} evidence for contribution to the 100GHz intensity from foreground CO along the line of sight to 147 sources with |b|>{30deg}. The median excess contribution is 4.5+/-0.9 per cent of their measured 100 GHz flux density which cannot be explained by calibration or beam uncertainties. This translates to 0.5+/-0.1K.km/s of CO which must be clumped on the scale of the Planck 100GHz beam, i.e. ~10-arcmin. If this is due to a population of low-mass (~15M_{sun}_) molecular gas clumps, the total mass in these clumps may be more than 2000 M_{sun}_. Further, high-spatial-resolution, ground-based observations of the high-latitude sky will help shed light on the origin of this diffuse, clumpy CO emission.
1254. Planck maps spots near RCR sources
ID:
ivo://CDS.VizieR/J/other/AstBu/76.109
Title:
Planck maps spots near RCR sources
Short Name:
J/other/AstBu/76
Date:
22 Feb 2022
Publisher:
CDS
Description:
The spectral properties of the inhomogeneities of the microwave background on Planck multi-frequency maps that are distant from the sources of the RCR catalog by the half-width of the power beam pattern of the high-frequency Planck complex (+/-2.5 arcmin), as well as the spectral features of the sources depending on the presence of positive spots near them, are studied. About 830 objects of the catalog were examined for the detection of spots with positive amplitudes near them. The features that indicate the connection of positive peaks on the Planck maps with the nearest radio sources are revealed. First, it is the excess of the number of RCR sources with flat and normal spectra, near which there are spots, over the number of sources with steep spectra. Secondly, the number of spots with positive amplitude on Planck maps that coincide within +/-2.5 arcmin with the coordinates of source-free areas on NVSS, FIRST maps and have the same sizes is on average almost one and a half times less than the number of spots that coincide with RCR objects. It is shown that RCR objects, near which there are no spots, have steeper spectra compared to the spectra of sources, near which spots are detected. The distribution of the spectral indices of spots in the range of 30--217 GHz was close to the distribution of the spectral indices of RCR sources in the range of 100MHz-8.5GHz and their median values almost coincided. This may indicate that the positive fluctuations on the Planck maps detected near RCR objects in the range of 30-217GHz are synchrotron in nature and may be associated with these objects. They can be manifestations of these objects or manifestations of their host galaxies and their environment in the submillimeter range. In the range of 353-857GHz, some of the detected spots can be classified as dusty. The spectra of RCR sources, near which such spots were detected, were steeper than the spectra of RCR objects, near which spots were detected only in the frequency channels 30-217GHz. The steeper the spectrum of the RCR object in the range of 100MHz-8.5GHz, the greater the value of the positive spectral index of the nearest spot in the range of 353-857GHz. The spots, whose two-frequency spectral indices indicate their dusty nature, may be associated with the high dust content in the host galaxies of RCR objects and the processes of star formation in them. It is also possible that the rise in the spectra at high frequencies may be caused by the presence of a signal from cold galactic dust on the frequency maps.
1255. Planetary Nebulae in NRAO VLA Sky Survey
ID:
ivo://CDS.VizieR/J/ApJS/123/219
Title:
Planetary Nebulae in NRAO VLA Sky Survey
Short Name:
J/ApJS/123/219
Date:
21 Oct 2021
Publisher:
CDS
Description:
In order to construct a sample of planetary nebulae (PNe) unbiased by dust extinction, we first selected the 1358 sources in the IRAS Point Source Catalog north of J2000 declination DE=-40{deg} having measured S(25{mu}m)>=1 Jy and colors characteristic of PNe: detections or upper limits consistent with both S(12{mu}m)<=0.35S(25{mu}m) and S(25{mu}m)>=0.35S(60{mu}m). The majority are radio-quiet contaminating sources such as asymptotic giant branch stars. Free-free emission from genuine PNe should make them radio sources. The 1.4 GHz NRAO VLA Sky Survey (NVSS) images and source catalog were used to reject radio-quiet mid-infrared sources. We identified 454 IRAS sources with radio sources brighter than S~2.5 mJy/beam (equivalent to T~0.8K in the 45" FHWM NVSS beam) by positional coincidence. They comprise 332 known PNe in the Strasbourg-ESO Catalogue of Galactic Planetary Nebulae and 122 candidate PNe, most of which lie at very low Galactic latitudes. Exploratory optical spectroscopic observations suggest that most of these candidates are indeed PNe optically dimmed by dust extinction, although some contamination remains from H II regions, Seyfert galaxies, etc. Furthermore, the NVSS failed to detect only 4% of the known PNe in our infrared sample. Thus it appears that radio selection can greatly improve the reliability of PN candidate samples without sacrificing completeness.
1256. PMN J0948+0022 radio-to-gamma-ray monitoring
ID:
ivo://CDS.VizieR/J/A+A/548/A106
Title:
PMN J0948+0022 radio-to-gamma-ray monitoring
Short Name:
J/A+A/548/A106
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present more than three years of observations at different frequencies, from radio to high-energy gamma-rays, of the Narrow-Line Seyfert 1 (NLS1) Galaxy PMN J0948+0022 (z=0.585). This source is the first NLS1 detected at energies above 100 MeV and therefore can be considered the prototype of this emerging new class of gamma-ray emitting active galactic nuclei (AGN). The observations performed from 2008 August 1 to 2011 December 31 confirmed that PMN J0948+0022 generates a powerful relativistic jet, able to develop an isotropic luminosity at gamma-rays of the order of 10^48^erg/s, at the level of powerful quasars. The evolution of the radiation emission of this source in 2009 and 2010 followed the canonical expectations of relativistic jets, with correlated multiwavelength variability (gamma-rays followed by radio emission after a few months), but it was difficult to retrieve a similar pattern in the light curves of 2011. The comparison of gamma-ray spectra before and including 2011 data suggested that there was a softening of the high-energy spectral slope. We selected five specific epochs to be studied by modelling the broad-band spectrum, characterised by an outburst at gamma-rays or very low/high flux at other wavelengths. The observed variability can largely be explained either by changes in the injected power, the bulk Lorentz factor of the jet or the electron spectrum. The characteristic time scale of doubling/halving flux ranges from a few days to a few months, depending on the frequency and the sampling rate. The shortest doubling time scale at gamma-rays is 2.3+/-0.5days. These small values underline the need of highly-sampled multiwavelength campaigns to better understand the physics of these sources.
1257. PMN map catalog of radiosources
ID:
ivo://CDS.VizieR/J/ApJS/90/173
Title:
PMN map catalog of radiosources
Short Name:
J/ApJS/90/173
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Parkes-MIT-NRAO (PMN) southern survey was made with the NRAO 4.85GHz seven-beam receiver on the Parkes 64 m telescope during 1990 June, and maps covering the Omega = 2.5 sr declination band -88{deg}<Dec.<-37{deg} were constructed from the survey scans. We present a catalog of 15,045 discrete sources with angular sizes phi<~15arcmin and stronger than S~25mJy derived from these maps. Machine-readable versions of the catalog with either B1950 or J2000 positions, and a printed catalog with B1950 positions only, are available. The 4.85GHz weighted source counts S^(5/2)^n(S) between 30mJy and 10Jy were obtained and agree well with previous results.
1258. PNe angular diameters from SED modeling
ID:
ivo://CDS.VizieR/J/MNRAS/503/2887
Title:
PNe angular diameters from SED modeling
Short Name:
J/MNRAS/503/2887
Date:
21 Oct 2021
Publisher:
CDS
Description:
Powerful new, high-resolution, high-sensitivity, multifrequency, wide-field radio surveys such as the Australian Square Kilometre Array Pathfinder (ASKAP) Evolutionary Map of the Universe are emerging. They will offer fresh opportunities to undertake new determinations of useful parameters for various kinds of extended astrophysical phenomena. Here, we consider specific application to angular-size determinations of Planetary Nebulae (PNe) via a new radio continuum spectral energy distribution fitting technique. We show that robust determinations of angular size can be obtained, comparable to the best optical and radio observations but with the potential for consistent application across the population. This includes unresolved and/or heavily obscured PNe that are extremely faint or even non-detectable in the optical.
1259. PNe in NRAO VLA Sky Survey
ID:
ivo://CDS.VizieR/J/ApJS/117/361
Title:
PNe in NRAO VLA Sky Survey
Short Name:
J/ApJS/117/361
Date:
21 Oct 2021
Publisher:
CDS
Description:
The 1.4GHz NRAO VLA Sky Survey (NVSS) images and source catalog were used to detect radio emission from the 885 planetary nebulae north of J2000 declination {delta}=-40{deg} in the Strasbourg-ESO Catalogue of Galactic Planetary Nebulae (Cat. <V/84>). We identified 680 radio sources brighter than about S=2.5mJy/beam (equivalent to T~0.8K in the 45" FWHM NVSS beam) with planetary nebulae by coincidence with accurate optical positions measured from Digitized Sky Survey (DSS) images. Total extinction coefficients c at {lambda}=4861{AA} were calculated for the 429 planetary nebulae with available H{beta} fluxes and low free-free optical depths at 1.4GHz. The variation of c with Galactic latitude and longitude is consistent with the extinction being primarily interstellar and not intrinsic.
1260. POETS luminous YSOs 13 or 22GHz images
ID:
ivo://CDS.VizieR/J/A+A/631/A74
Title:
POETS luminous YSOs 13 or 22GHz images
Short Name:
J/A+A/631/A74
Date:
21 Oct 2021
Publisher:
CDS
Description:
Although recent observations and theoretical simulations have pointed out that accretion disks and jets can be essential for the formation of stars with a mass of up to at least 20M_{sun}_, the processes regulating mass accretion and ejection are still uncertain. The goal of the Protostellar Outflows at the EarliesT Stages (POETS) survey is to image the disk-outflow interface on scales of 10-100au in a statistically significant sample (36) of luminous young stellar objects (YSO), targeting both the molecular and ionized components of the outflows. The outflow kinematics is studied at milliarcsecond scales through very long baseline interferometry (VLBI) observations of the 22GHz water masers, which are ideal test particles to measure the three-dimensional (3D) motion of shocks owing to the interaction of winds and jets with ambient gas. We employed the Jansky Very Large Array (JVLA) at 6, 13, and 22GHz in the Aand B-Array configurations to determine the spatial structure and the spectral index of the radio continuum emission, and address its nature. In about half of the targets, the water masers observed at separation <=1000au from the YSOs trace either or both of these kinematic structures: 1) a spatially elongated distribution oriented at close angle with the direction of collimation of the maser proper motions (PM), and 2) a linear local standard of rest (LSR) velocity (VLSR) gradient across the YSO position. The kinematic structure (1) is readily interpreted in terms of a protostellar jet, as confirmed in some targets via the comparison with independent observations of the YSO jets, in thermal (continuum and line) emissions, reported in the literature. The kinematic structure (2) is interpreted in terms of a disk-wind (DW) seen almost edge-on on the basis of several pieces of evidence: first, it is invariably directed perpendicular to the YSO jet; second, it agrees in orientation and polarity with the VLSR gradient in thermal emissions (when reported in the literature) identifying the YSO disk at scales of <=1000au; third, the PMs of the masers delineating the VLSR gradients hint at flow motions at a speed of 10-20km/s directed at large angles with the disk midplane. In the remaining targets, the maser PMs are not collimated but rather tend to align along two almost perpendicular directions. To explain this peculiar PM distribution, and in light of the observational bias strongly favoring masers moving close to the plane of sky, we propose that, in these sources, the maser emission could originate in DW-jet systems slightly inclined (<=30{deg}) with respect to edge-on. Magneto-centrifugally driven DWs could in general account for the observed velocity patterns of water masers.