- ID:
- ivo://CDS.VizieR/J/A+A/633/A54
- Title:
- B0355+508 reduced spectra
- Short Name:
- J/A+A/633/A54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Phosphorus-bearing species are essential to the formation of life on Earth, however they have barely been detected in the interstellar medium. In particular, towards star-forming regions only PN and PO have been identified so far. Since only a small number of detections of P-bearing molecules are available, their chemical formation pathways are not easy to constrain and are thus highly debatable. An important factor still missing in the chemical models is the initial elemental abundance of phosphorus, that is, the depletion level of P at the start of chemical models of dense clouds. In order to overcome this problem, we study P-bearing species in diffuse and translucent clouds. In these objects phosphorus is expected to be mainly in the gas phase and therefore the elemental initial abundance needed in our chemical simulations corresponds to the cosmic one and is well constrained. For the study of P-bearing chemistry we used an advanced chemical model. We updated and significantly extended the P-chemistry network based on chemical databases and previous literature. We performed single-pointing observations with the IRAM 30m telescope in the 3mm range towards the line of sight to the strong continuum source B0355+508 aiming for the (2-1) transitions of PN, PO, HCP, and CP. This line of sight incorporates five diffuse and/or translucent clouds. The (2-1) transitions of the PN, PO, HCP, and CP were not detected. We report high signal-to-noise-ratio detections of the (1-0) lines of ^13^CO, HNC, and CN along with a first detection of C^34^S towards this line of sight. We have attempted to reproduce the observations of HNC, CN, CS, and CO in every cloud with our model by applying typical physical conditions for diffuse or translucent clouds. We find that towards the densest clouds with v_LSR_= -10, -17 km/s the best-fit model is given by the parameters (n_H_, A_V_, T_gas_) = (300cm^-3^, 3mag, 40K). According to our best-fit model, the most abundant P-bearing species are HCP and CP (1e-10). The molecules PN, PO, and PH_3_ also show relatively high predicted abundances of 1e-11. We show that the abundances of these species are sensitive to visual extinction, cosmic-ray ionization rate, and the diffusion-to-desorption energy ratio on dust grains. The production of P-bearing species is favored towards translucent rather than diffuse clouds, where the environment provides a stronger shielding from the interstellar radiation. Based on our improved model, we show that the (1-0) transitions of HCP, CP, PN, and PO are expected to be detectable with estimated intensities of up to ~200mK.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/460/3669
- Title:
- Brightest cluster galaxies Radio luminosity
- Short Name:
- J/MNRAS/460/3669
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- By cross-matching the currently largest optical catalogue of galaxy clusters and the NVSS radio survey data base, we obtain a large complete sample of brightest cluster galaxies (BCGs) in the redshift range of 0.05<z<=0.45, which have radio emission and redshift information. We confirm that more powerful radio BCGs tend to be these optically very bright galaxies located in more relaxed clusters. We derived the radio luminosity functions of the largest sample of radio BCGs, and find that the functions depend on the optical luminosity of BCGs and the dynamic state of galaxy clusters. However, the radio luminosity function does not show significant evolution with redshift.
- ID:
- ivo://CDS.VizieR/J/MNRAS/216/173
- Title:
- Bright extragalactic radio sources at 2.7 GHz
- Short Name:
- J/MNRAS/216/173
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The brightest extragalactic radio sources at 2.7 GHz are catalogued. The complete sample comprises 233 sources found in the major centimeter wavelength surveys carried out at ANRAO/Parkes, NNRAO/Greenbank, and MPIfR/Bonn: the sample covers 9.81 sr and has limits S(27) = 2.0 Jy and |b| > 10{deg}. A critical reanalysis of the data shows that 227 (97 percent) have optical identifications and 171 (73 percent) have measured redshifts. The implications of the catalogue statistics for the luminosity functions of different radio-source populations are considered.
- ID:
- ivo://CDS.VizieR/VIII/5
- Title:
- Bright Extragalactic Radio Sources (1Jy)
- Short Name:
- VIII/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog is a compilation of 518 extragalactic radio sources with flux densities greater than 1 Jy at 5 GHz. It contains sources from the NRAO-MPI 5-GHz Strong Source Surveys and from re-observation at 5 GHz of sources found in the Parkes 2.7-GHz surveys. All sources were found in 9.811 sr covered by the two surveys. This is essentially the whole sky, excluding the galactic plane (latitudes less than 10 degrees) and the Magellanic Clouds. The catalog includes radio flux densities, radio positions, object classes, visual magnitudes, redshifts, and spectral indices.
- ID:
- ivo://CDS.VizieR/J/A+A/339/34
- Title:
- Bright galaxies from the WENSS minisurvey
- Short Name:
- J/A+A/339/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A search for bright galaxies associated with radio sources from the Westerbork Northern Sky Survey (WENSS) minisurvey has been carried out. A galaxy counterpart was found for 402 of almost 10,000 radio sources. Of these a radio and optically complete sample, with a flux density limit at 325MHz of 30mJy and a limiting red magnitude of 16, can be constructed, which contains 119 galaxies. This paper is the first step of a more general study, in which we aim to derive a bright galaxy sample from the entire WENSS survey (which is now available in the public domain) and thus to construct practically definitive local radio luminosity functions of elliptical and spiral galaxies. We briefly describe the WENSS minisurvey, and the steps that are needed for the optical identification of its radio sources. Due to the large numbers of sources involved (over 200,000) completely automated procedures are obviously needed and we discuss these in some detail. It is shown that with modern utilities projects as described here have become quite feasible. Some results (e.g. a preliminary determination of the local radio luminosity function) are presented.
- ID:
- ivo://CDS.VizieR/J/A+A/549/A133
- Title:
- Bright northern radio sources with VLA/JVLA
- Short Name:
- J/A+A/549/A133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report multiple epoch VLA/JVLA observations of 89 northern hemisphere sources, most with 37GHz flux density >1Jy, observed at 4.8, 8.5, 33.5, and 43.3GHz. The high frequency selection leads to a predominantly flat spectrum sample, with 85% of our sources being in the Planck Early Release Compact Source Catalog (ERCSC, Cat. VIII/88). These observations allow us to: 1) validate Planck's 30 and 44GHz flux density scale; 2) extend the radio spectral energy distributions of Planck sources to lower frequencies allowing for the full 5-857GHz regime to be studied; and 3) characterize the variability of these sources. At 30GHz and 44GHz, the JVLA and Planck flux densities agree to within ~3%. On timescales of less than two months the median variability of our sources is 2%. On timescales of about a year the median variability increases to 14%. Using the WMAP 7-year data, the 30GHz median variability on a 1-6 years timescale is 16%.
- ID:
- ivo://CDS.VizieR/J/MNRAS/204/151
- Title:
- Bright radio sources at 178 MHz (3CRR)
- Short Name:
- J/MNRAS/204/151
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A revised sample of bright radio sources at 178MHz is defined in order to correct the biases introduced into the 3CR catalog by confusion and partial resolution. The sample is shown to be 96 percent complete to a flux-density limit of 10Jy for sources smaller than 10arcmin. The bias of the 3CR catalog against objects of larger angular size is also reduced. Optical identifications are presented for 96 percent of the sources, 71 percent with galaxies and 25 percent with quasars. The radio-galaxy population is found to show strong space-density evolution for luminosities in excess of approximately 10^26.5^W/Hz/sr at 178MHz (redshifts greater than or approximately equal to 0.2), while the evolutionary properties of galaxies and quasars of the same luminosity and redshift are very similar.
- ID:
- ivo://CDS.VizieR/J/MNRAS/384/775
- Title:
- Bright Source Sample of AT20G Survey
- Short Name:
- J/MNRAS/384/775
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Australia Telescope 20-GHz (AT20G) Survey is a blind survey of the whole southern sky at 20GHz (with follow-up observations at 4.8 and 8.6GHz) carried out with the Australia Telescope Compact Array from 2004 to 2007. The Bright Source Sample (BSS) is a complete flux-limited subsample of the AT20G Survey catalogue comprising 320 extragalactic (|b|>1.5{deg}) radio sources south of DE=-15{deg} with S_20GHz_>0/50Jy. Of these, 218 have near simultaneous observations at 8 and 5GHz. In this paper we present an analysis of radio spectral properties in total intensity and polarization, size, optical identifications and redshift distribution of the BSS sources.
- ID:
- ivo://CDS.VizieR/J/A+A/376/1123
- Title:
- Bright southern sub-mm sources
- Short Name:
- J/A+A/376/1123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table1 contains the 130 brightest sources of a 230GHz survey of quasars and BL Lacertae objects performed at the SEST. The objects which showed a 230GHz flux density above500 mJy most of the time were selected as pointing sources. Name, coordinates (B1950) and type are given in the table. Due to the variability of many objects the minimum and maximum flux density at 230GHz is given as well. A few values are taken from literature. These data are marked with an asterisk.
- ID:
- ivo://CDS.VizieR/J/A+A/606/A8
- Title:
- Bubble HII region Sh2-39 (N5)
- Short Name:
- J/A+A/606/A8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Aiming at studying the physical properties of Galactic IR bubbles and to explore their impact in triggering massive star formation, we perform a multiwavelength analysis of the bubble HII region Sh2-39 (N5) and its environs. To analyze the molecular gas we use CO(3-2) and HCO^+^(4-3) line data obtained with the on-the-fly technique from the ASTE telescope. To study the distribution and physical characteristics of the dust, we make use of archival data from ATLASGAL, Herschel, and MSX, while the ionized gas was studied making use of an NVSS image. We use public WISE, Spitzer, and MSX point source catalogs to search for infrared candidate YSOs in the region. To investigate the stellar cluster [BDS2003] 6 we use IR spectroscopic data obtained with the ARCoIRIS spectrograph, mounted on Blanco 4-m Telescope at CTIO, and new available IR Ks band observations from the VVVeXtended ESO Public Survey (VVVX). The new ASTE observations allowed the molecular gas component in the velocity range from 30km/s to 46km/s, associated with Sh2-39, to be studied in detail. The morphology of the molecular gas suggests that the ionized gas is expanding against its parental cloud. We have identified four molecular clumps, that were likely formed by the expansion of the ionization front, and determined some of their physical and dynamical properties. Clumps having HCO^+^ and 870um counterparts show evidence of gravitational collapse. We identified several candidate YSOs across the molecular component. Their spatial distribution, as well as the fragmentation time derived for the collected layers of the molecular gas, suggest that massive star formation might have been triggered by the expansion of the nebula via the collect and collapse mechanism. The spectroscopical distance obtained for the stellar cluster [BDS2003] 6, placed over one of the collapsing clumps in the border of the HII region, reveals that this cluster is physically associated with the nebula and gives more support to the triggered massive star formation scenario. A radio continuum data analysis indicates that the nebula is older and expands at lower velocity than typical IR Galactic bubbles.