- ID:
- ivo://CDS.VizieR/J/A+A/628/A110
- Title:
- Photometry of submm cores in Vela C
- Short Name:
- J/A+A/628/A110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a study of the population of compact submm cores in Vela C, one of the molecular clouds making up the Vela Molecular Ridge, a nearby (~700pc) star forming region in the Galactic plane. A large scale map of dust emission at 345GHz was obtained with LABOCA at the APEX telescope. Core retrieval and photometry were performed with the algorithms CuTEx and CLUMPFIND. Table 1 lists the sources retrieved by CuTEx. Table 2 lists the sources retrieved by CLUMPFIND.
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- ID:
- ivo://CDS.VizieR/J/A+A/655/A86
- Title:
- PILS-Cygnus. observations of CygX-N30
- Short Name:
- J/A+A/655/A86
- Date:
- 10 Mar 2022 07:33:06
- Publisher:
- CDS
- Description:
- Complex organic molecules (COMs) are commonly detected in and near star-forming regions. However, the dominant process in the release of these COMs from the icy grains -- where they predominately form -- to the gas phase is still an open question. We investigate the origin of COM emission in a high-mass protostellar source, CygX-N30 MM1, through high-angular-resolution interferometric observations over a continuous broad frequency range. We used 32 GHz Submillimeter Array (SMA) observations with continuous frequency coverage from 329 to 361GHz at an angular resolution of ~1'' to do a line survey and obtain a chemical inventory of the source. The line emission in the frequency range was used to determine column densities and excitation temperatures for the COMs. We also mapped out the intensity distribution of the different species. We identified approximately 400 lines that can be attributed to 29 different molecular species and their isotopologues. We find that the molecular peak emission is along a linear gradient, and coincides with the axis of red- and blue- shifted H_2_CO and CS emission. Chemical differentiation is detected along this gradient, with the O-bearing molecular species peaking towards one component of the system and the N- and S-bearing species peaking towards the other. The chemical gradient is offset from but parallel to the axis through the two continuum sources. The inferred column densities and excitation temperatures are compared to other sources where COMs are abundant. Only one deuterated molecule is detected, HDO, while an upper limit for CH_2_DOH is derived, leading to a D/H ratio of <0.1%. We conclude that the origin of the observed COM emission is probably a combination of the young stellar sources along with accretion of infalling material onto a disc-like structure surrounding a young protostar and located close to one of the continuum sources. This disc and protostar are associated with the O-bearing molecular species, while the S- and N- bearing species on the other hand are associated with the other continuum core, which is probably a protostar that is slightly more evolved than the other component of the system. The low D/H ratio likely reflects a pre- stellar phase where the COMs formed on the ices at warm temperatures (~30K), where the deuterium fractionation would have been inefficient. The observations and results presented here demonstrate the importance of good frequency coverage and high angular resolution when disentangling the origin of COM emission.
- ID:
- ivo://CDS.VizieR/J/A+A/604/A65
- Title:
- Planck and Herschel images combination
- Short Name:
- J/A+A/604/A65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Herschel has revolutionized our ability to measure column densities (N_H_) and temperatures (T) of molecular clouds thanks to its far infrared multiwavelength coverage. However, the lack of a well defined background intensity level in the Herschel data limits the accuracy of the NH and T maps. We aim to provide a method that corrects the missing Herschel background intensity levels using the Planck model for foreground Galactic thermal dust emission. For the Herschel/PACS data, both the constant-offset as well as the spatial dependence of the missing background must be addressed. For the Herschel/SPIRE data, the constant-offset correction has already been applied to the archival data so we are primarily concerned with the spatial dependence, which is most important at 250um. We present a Fourier method that combines the publicly available Planck model on large angular scales with the Herschel images on smaller angular scales. We have applied our method to two regions spanning a range of Galactic environments: Perseus and the Galactic plane region around l=11{deg} (HiGal-11). We post-processed the combined dust continuum emission images to generate column density and temperature maps. We compared these to previously adopted constant-offset corrections. We find significant differences (>~20%) over significant (~15%) areas of the maps, at low column densities (N_H_<~10^22^cm^-2^) and relatively high temperatures (T>~20K). We have also applied our method to synthetic observations of a simulated molecular cloud to validate our method. Our method successfully corrects the Herschel images, including both the constant-offset intensity level and the scale-dependent background variations measured by Planck. Our method improves the previous constant-offset corrections, which did not account for variations in the background emission levels.
- ID:
- ivo://CDS.VizieR/VIII/91
- Title:
- Planck Catalog of Compact Sources Release 1
- Short Name:
- VIII/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Planck is a European Space Agency (ESA) mission, with significant contributions from the U.S. National Aeronautics and Space Agency (NASA). It is the third generation of space-based cosmic microwave background experiments, after the Cosmic Background Explorer (COBE) and the Wilkinson Microwave Anisotropy Probe (WMAP). Planck was launched on 14 May 2009 on an Ariane 5 rocket from Kourou, French Guiana. Following a cruise to the Earth-Sun L2 Lagrange point, cooling and in orbit checkout, Planck initiated the First Light Survey on 13 August 2009. Since then, Planck has been continuously measuring the intensity of the sky over a range of frequencies from 30 to 857GHz (wavelengths of 1cm to 350{mu}m) with spatial resolutions ranging from about 33' to 5' respectively. The Low Frequency Instrument (LFI) on Planck provides temperature and polarization information using radiometers which operate between 30 and 70GHz. The High Frequency Instrument (HFI) uses pairs of polarization-sensitive bolometers at each of four frequencies between 100 and 353GHz but does not measure polarization information in the two upper HFI bands at 545 and 857GHz. The lowest frequencies overlap with WMAP, and the highest frequencies extend far into the submillimeter in order to improve separation between Galactic foregrounds and the cosmic microwave background (CMB). By extending to wavelengths longer than those at which the Infrared Astronomical Satellite (IRAS) operated, Planck is providing an unprecedented window into dust emission at far-infrared and submillimeter wavelengths. The PCCS (Planck Catalog of Compact Sources) is the list of sources detected in the first 15 months of Planck "nominal" mission. It consists of nine single-frequency catalogues of compact sources, both Galactic and extragalactic, detected over the entire sky. The PCCS covers the frequency range 30-857 GHz with higher sensitivity (it is 90% complete at 180mJy in the best channel) and better angular resolution than previous all-sky surveys in the microwave band. By construction its reliability is >80% and more than 65% of the sources have been detected at least in two contiguous Planck channels. Many of the Planck PCCS sources can be associated with stars with dust shells, stellar cores, radio galaxies, blazars, infrared luminous galaxies and Galactic interstellar medium features.
- ID:
- ivo://CDS.VizieR/J/ApJS/224/43
- Title:
- Planck cold clumps and cores in the 2nd quadrant
- Short Name:
- J/ApJS/224/43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Ninety-six Planck cold dust clumps in the second quadrant were mapped with ^12^CO(1-0), ^13^CO(1-0), and C^18^O(1-0) lines at the 13.7m telescope of Purple Mountain Observatory. ^12^CO(1-0) and ^13^CO(1-0) emissions were detected for all 96 clumps, while C^18^O(1-0) emissions were detected in 81 of them. Fifteen clumps have more than one velocity component. In the 115 mapped velocity components, 225 cores were obtained. We found that 23.1% of the cores have non-Gaussian profiles. We acquired the V_lsr_, FWHM, and T_A_ of the lines. Distances, T_ex_, velocity dispersions, N_H_2__, and masses were also derived. Generally, turbulence may dominant the cores because {sigma}_NT_/{sigma}_Therm_>1 in almost all of the cores and Larson's relationship is not apparent in our massive cores. Virial parameters are adopted to test the gravitational stability of cores and 51% of the cores are likely collapsing. The core mass function of the cores in the range 0-1kpc suggests a low core-to-star conversional efficiency (0.62%). Only 14 of 225 cores (6.2%) have associated stellar objects at their centers, while the others are starless. The morphologies of clumps are mainly filamentary structures. Seven clumps may be located on an extension of the new spiral arm in the second quadrant while three are on the known outer arm.
- ID:
- ivo://CDS.VizieR/J/ApJS/254/14
- Title:
- Planck Cold Clumps in the lambda Orionis complex. III.
- Short Name:
- J/ApJS/254/14
- Date:
- 17 Jan 2022 00:15:36
- Publisher:
- CDS
- Description:
- Massive stars have a strong impact on their local environments. However, how stellar feedback regulates star formation is still under debate. In this context, we studied the chemical properties of 80 dense cores in the Orion molecular cloud complex composed of the Orion A (39 cores), B (26 cores), and {lambda} Orionis (15 cores) clouds using multiple molecular line data taken with the Korean Very Long Baseline Interferometry Network 21m telescopes. The {lambda} Orionis cloud has an HII bubble surrounding the O-type star {lambda} Ori, and hence it is exposed to the ultraviolet (UV) radiation field of the massive star. The abundances of C_2_H and HCN, which are sensitive to UV radiation, appear to be higher in the cores in the {lambda} Orionis cloud than in those in the Orion A and B clouds, while the HDCO to H_2_CO abundance ratios show the opposite trend, indicating warmer conditions in the {lambda} Orionis cloud. The detection rates of dense gas tracers such as the N_2_H^+^, HCO^+^, and H^13^CO^+^ lines are also lower in the {lambda} Orionis cloud. These chemical properties imply that the cores in the {lambda} Orionis cloud are heated by UV photons from {lambda} Ori. Furthermore, the cores in the {lambda} Orionis cloud do not show any statistically significant excess in the infall signature of HCO^+^ (1-0), unlike those in the Orion A and B clouds. Our results support the idea that feedback from massive stars impacts star formation in a negative way by heating and evaporating dense materials, as in the {lambda} Orionis cloud.
- ID:
- ivo://CDS.VizieR/VIII/88
- Title:
- Planck Early Release Compact Source Catalogue
- Short Name:
- VIII/88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Planck is a European Space Agency (ESA) mission, with significant contributions from the U.S. National Aeronautics and Space Agency (NASA). It is the third generation of space-based cosmic microwave background experiments, after the Cosmic Background Explorer (COBE) and the Wilkinson Microwave Anisotropy Probe (WMAP). Planck was launched on 14 May 2009 on an Ariane 5 rocket from Kourou, French Guiana. Following a cruise to the Earth-Sun L2 Lagrange point, cooling and in orbit checkout, Planck initiated the First Light Survey on 13 August 2009. Since then, Planck has been continuously measuring the intensity of the sky over a range of frequencies from 30 to 857GHz (wavelengths of 1cm to 350{mu}m) with spatial resolutions ranging from about 33' to 5' respectively. The Low Frequency Instrument (LFI) on Planck provides temperature and polarization information using radiometers which operate between 30 and 70GHz. The High Frequency Instrument (HFI) uses pairs of polarization-sensitive bolometers at each of four frequencies between 100 and 353GHz but does not measure polarization information in the two upper HFI bands at 545 and 857GHz. The lowest frequencies overlap with WMAP, and the highest frequencies extend far into the submillimeter in order to improve separation between Galactic foregrounds and the cosmic microwave background (CMB). By extending to wavelengths longer than those at which the Infrared Astronomical Satellite (IRAS) operated, Planck is providing an unprecedented window into dust emission at far-infrared and submillimeter wavelengths. The Planck Early Release Compact Source Catalogue (ERCSC) is a list of all high reliability sources, both Galactic and extragalactic, derived from the first sky coverage. The data that went into this early release comprise all observations undertaken between 13 August 2009 and 6 June 2010, corresponding to Planck operational days 91-389. Since the Planck scan strategy results in the entire sky being observed every 6 months, the data considered in this release correspond to more than the first sky coverage. The source lists have reliability goals of >90% across the entire sky and >95% at high Galactic latitude. The goals on photometric accuracy are 30% while the positional accuracy goal translates to a positional root mean square (RMS) uncertainty that is less than 1/5 of the beam full width at half maximum (FWHM). Detailed explanations about the mission and the catalogs included here can be found in the "Explanatory supplement" (file "ercsc4_3.pdf"). Skymaps of the sources can be found in the "skymaps" subdirectory; postage stamps of the sources in the ECC (Early Cold Cores) catalog and in the different filters are located in the "stamps" subdirectory. The "Byte-by-byte Description" below contain column names standardized according to the conventions used at CDS; the original column names, as defined in the FITS files, are listed, enclosed within parentheses, at the end of the explanations.
- 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.
- ID:
- ivo://CDS.VizieR/J/PAZh/43/559
- Title:
- Planck galaxy cluster catalogue extension
- Short Name:
- J/PAZh/43/559
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of galaxy clusters detected in the Planck all-sky Compton parameter maps and identified using data from the WISE and SDSS surveys. The catalogue comprises about 3000 clusters in the SDSS fields. We expect the completeness of this catalogue to be high for clusters with masses larger than M500~=3x10^14^M_{sun}_, located at redshifts z<0.7. At redshifts above z~=0.4, the catalogue contains approximately an order of magnitude more clusters than the 2nd Planck Catalogue of Sunyaev-Zeldovich sources in the same fields of the sky. This catalogue can be used for identification of massive galaxy clusters in future large cluster surveys, such as the SRG/eROSITA all-sky X-ray survey.
- ID:
- ivo://CDS.VizieR/J/A+A/596/A100
- Title:
- Planck high-z source candidates catalog (PHZ)
- Short Name:
- J/A+A/596/A100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Planck mission, thanks to its large frequency range and all-sky coverage, has a unique potential for systematically detecting the brightest, and rarest, submillimetre sources on the sky, including distant objects in the high-redshift Universe traced by their dust emission. A novel method, based on a component-separation procedure using a combination of Planck and IRAS data, has been validated and characterized on numerous simulations, and applied to select the most luminous cold submillimetre sources with spectral energy distributions peaking between 353 and 857GHz at 5' resolution. A total of 2151 Planck high-z source candidates (the PHZ) have been detected in the cleanest 26% of the sky, with flux density at 545GHz above 500mJy. Embedded in the cosmic infrared background close to the confusion limit, these high-z candidates exhibit colder colours than their surroundings, consistent with redshifts z>2, assuming a dust temperature of Txgal=35K and a spectral index of {beta}xgal=1.5. Exhibiting extremely high luminosities, larger than 10^14^L_{sun}_, the PHZ objects may be made of multiple galaxies or clumps at high redshift, as suggested by a first statistical analysis based on a comparison with number count models. Furthermore, first follow-up observations obtained from optical to submillimetre wavelengths, which can be found in companion papers, have confirmed that this list consists of two distinct populations. A small fraction (around 3%) of the sources have been identified as strongly gravitationally lensed star-forming galaxies at redshift 2 to 4, while the vast majority of the PHZ sources appear as overdensities of dusty star-forming galaxies, having colours consistent with being at z>2, and may be considered as proto-cluster candidates. The PHZ provides an original sample, which is complementary to the Planck Sunyaev-Zeldovich Catalogue (PSZ2); by extending the population of virialized massive galaxy clusters detected below z<1.5 through their SZ signal to a population of sources at z>1.5, the PHZ may contain the progenitors of today's clusters. Hence the Planck list of high-redshift source candidates opens a new window on the study of the early stages of structure formation, particularly understanding the intensively star-forming phase at high-z.
