- ID:
- ivo://CDS.VizieR/J/AJ/137/4436
- Title:
- Coma cluster VLA survey
- Short Name:
- J/AJ/137/4436
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep 1.4GHz Very Large Array radio continuum observations of two ~0.5{deg}^2^ fields in the Coma cluster of galaxies. The two fields, "Coma 1" and "Coma 3", correspond to the cluster core and southwest infall region and were selected on account of abundant preexisting multiwavelength data. In their most sensitive regions the radio data reach 22uJy rms per 4.4" beam, sufficient to detect (at 5{sigma}) Coma member galaxies with L_1.4GHz_=1.3x10^20^W/Hz. The full catalog of radio detections is presented herein and consists of 1030 sources detected at >=5{sigma}, 628 of which are within the combined Coma 1 and Coma 3 area. We also provide optical identifications of the radio sources using data from the Sloan Digital Sky Survey. The depth of the radio observations allows us to detect active galactic nucleus in cluster elliptical galaxies with M_r_<-20.5 (AB magnitudes), including radio detections for all cluster ellipticals with M_r_<-21.8. At fainter optical magnitudes (-20.5<M_r_~<-19), the radio sources are associated with star-forming galaxies with star formation rates as low as 0.1M_{sun}_/yr.
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172. CO maps in Serpens
- ID:
- ivo://CDS.VizieR/J/A+A/519/A27
- Title:
- CO maps in Serpens
- Short Name:
- J/A+A/519/A27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Serpens North cluster is a nearby low mass star forming region which is part of the Gould belt. It contains a range of young stars thought to correspond to two different bursts of star formation and provides the opportunity to study different stages of cluster formation. This work aims to study the molecular gas in the Serpens North cluster to probe the origin of the most recent burst of star formation in Serpens. Transitions of the C^17^O and C^18^O observed with the IRAM 30m telescope and JCMT are used to study the mass and velocity structure of the region while the physical properties of the gas are derived using LTE and non-LTE analyses of the three lowest transitions of C^18^O.
- ID:
- ivo://CDS.VizieR/J/A+A/489/217
- Title:
- CO maps of diffuse Galactic gas towards NRAO 150
- Short Name:
- J/A+A/489/217
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To understand the environment and extended structure of the host galactic gas whose molecular absorption line chemistry, we previously observed along the microscopic line of sight to the blazar/radio-continuum source NRAO 150 (aka B0355+508). We used the IRAM 30m Telescope and Plateau de Bure Interferometer to make two series of images of the host gas: i) 22.5" resolution single-dish maps of ^12^CO J=1-0 and 2-1 emission over a 220" by 220" field; ii) a hybrid (interferometer+singledish) aperture synthesis mosaic of ^12^CO J=1-0 emission at 5.8" resolution over a 90"-diameter region. At 22.5" resolution, the CO J=1-0 emission toward NRAO 150 is 30-100% brighter at some velocities than seen previously with 1' resolution, and there are some modest systematic velocity gradients over the 220" field. Of the five CO components seen in the absorption spectra, the weakest ones are absent in emission toward NRAO 150 but appear more strongly at the edges of the region mapped in emission. The overall spatial variations in the strongly emitting gas have Poisson statistics with rms fluctuations about equal to the mean emission level in the line wings and much of the line cores. The J=2-1/J=1-0 line ratios calculated pixel-by-pixel cluster around 0.7. At 6" resolution, disparity between the absorption and emission profiles of the stronger components has been largely ameliorated. The ^12^CO J=1-0 emission exhibits i) remarkably bright peaks, Tmb=12-13K, even as 4" from NRAO 150; ii) smaller relative levels of spatial fluctuation in the line cores, but a very broad range of possible intensities at every velocity; and iii) striking kinematics whereby the monotonic velocity shifts and supersonically broadened lines in 22.5" spectra are decomposed into much stronger velocity gradients and abrupt velocity reversals of intense but narrow, probably subsonic, line cores. CO components that are observed in absorption at a moderate optical depth (0.5) and are undetected in emission at 1' resolution toward NRAO 150 remain undetected at 6" resolution. This implies that they are not a previously-hidden large-scale molecular component revealed in absorption, but they do highlight the robustness of the chemistry into regions where the density and column density are too low to produce much rotational excitation, even in CO. Bright CO lines around NRAO 150 most probably reflect the variation of a chemical process, i.e. the C+-CO conversion. However, the ultimate cause of the variations of this chemical process in such a limited field of view remains uncertain.
- ID:
- ivo://CDS.VizieR/J/A+A/510/A5
- Title:
- CO(2-1) maps of IRAS 00117+6412
- Short Name:
- J/A+A/510/A5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our main aim is to study the influence of the initial conditions of a cloud in the intermediate/high-mass star formation process. We observed with the VLA, PdBI, and SMA the centimeter and millimeter continuum, N_2_H^+^ (1-0), and CO (2-1) emission associated with a dusty cloud harboring a nascent cluster with intermediate-mass protostars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/390/819
- Title:
- Combined NVSS-FIRST Galaxies (CoNFIG) sample
- Short Name:
- J/MNRAS/390/819
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CoNFIG (Combined NVSS-FIRST Galaxies) sample is a new sample of 274 bright radio sources at 1.4GHz. It was defined by selecting all sources with S1.4GHz-1.3Jy from the NRAO Very Large Array (VLA) Sky Survey (NVSS) in the north field of the Faint Images of the Radio Sky at Twenty centimetres (FIRST) survey. New radio observations obtained with the VLA for 31 of the sources are presented. The sample has complete Fanaroff-Riley (FRI)/FRII morphology identification; optical identifications and redshifts are available for 80 and 89 per cent of the sample, respectively, yielding a mean redshift of ~0.71. One of the goals of this survey is to get better definitions of luminosity distributions and source counts of FRI/FRII sources separately, in order to determine the evolution of the luminosity function for each type of source. We present a preliminary analysis, showing that these data are an important step towards examining various evolutionary schemes for these objects and to confirm or correct the dual population unified scheme for radio active galactic nuclei (AGN). Improving our understanding of radio galaxy evolution will give better insight into the role of AGN feedback in galaxy formation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/404/1719
- Title:
- Combined NVSS-FIRST galaxies (CoNFIG) sample II
- Short Name:
- J/MNRAS/404/1719
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper focuses on a comparison of the space densities of Fanaroff-Riley type I (FR I) and FR II sources at different epochs, with a particular focus on FR I sources. First, we present the concluding steps in constructing the Combined NVSS-FIRST Galaxies (CoNFIG) catalogue, including new Very Large Array observations, optical identifications and redshift estimates. The final catalogue consists of 859 sources over four samples (CoNFIG-1, -2, -3 and -4 with flux density limits of S1.4GHz=1.3, 0.8, 0.2 and 0.05Jy, respectively). It is 95.7 per cent complete in radio morphology classification and 74.3 per cent of the sources have redshift data. Combining CoNFIG with complementary samples, the distribution and evolution of FR I and FR II sources are investigated. We find that FR I sources undergo mild evolution and that, at the same radio luminosity, FR I and FR II sources show similar space density enhancements in various redshift ranges, possibly implying a common evolution.
- ID:
- ivo://CDS.VizieR/J/ApJS/247/57
- Title:
- Compact bright radio-loud AGNs. III. VLBA 43GHz
- Short Name:
- J/ApJS/247/57
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from the 43GHz Very Long Baseline Array (VLBA) observations of 124 compact radio-loud active galactic nuclei (AGNs) that were conducted between 2014 November and 2016 May. The typical dimensions of the restoring beam in each image are about 0.5masx0.2mas. The highest resolution of 0.2mas corresponds to a physical size of 0.02pc for the lowest redshift source in the sample. The 43GHz very long baseline interferometry (VLBI) images of 97 AGNs are presented for the first time. We study the source compactness on milliarcsecond and submilliarcsecond scales, and suggest that 95 sources in our sample are suitable for future space VLBI observations. By analyzing our data supplemented with other VLBA AGN surveys from the literature, we find that the core brightness temperature increases with increasing frequency below a break frequency ~7GHz, and decreases between ~7 and 240GHz but increases again above 240GHz in the rest frame of the sources. This indicates that the synchrotron opacity changes from optically thick to thin. We also find a strong statistical correlation between radio and {gamma}-ray flux densities. Our correlation is tighter than those in the literature derived from lower-frequency VLBI data, suggesting that the {gamma}-ray emission is produced more cospatially with the 43GHz VLBA core emission. This correlation can also be extrapolated to the unbeamed AGN population, implying that a universal {gamma}-ray production mechanism might be at work for all types of AGNs.
- ID:
- ivo://CDS.VizieR/J/ApJS/145/83
- Title:
- Compact radio sources at -30<Dec<0
- Short Name:
- J/ApJS/145/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 321 compact radio sources in the declination range 0{deg}>{delta}>-30{deg}. The positions of these sources have been measured with a two-dimensional rms accuracy of 35milliarcseconds using the NRAO Very Large Array. Each source has a peak flux density >50mJy at 8.4GHz. We intend for this catalog to be used mainly for selection of phase calibration sources for radio interferometers, although compact radio sources have other scientific uses.
- ID:
- ivo://CDS.VizieR/J/A+AS/126/325
- Title:
- Compact Radio Sources in & behind LMC catalogue
- Short Name:
- J/A+AS/126/325
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a continuum snapshot survey of a 3x4{deg}^2^ region of the Large Magellanic Cloud including the area of the giant molecular cloud and the 30 Doradus nebula. The observations have been carried out with the Australia Telescope Compact Array (ATCA) at 1.4 and 2.4GHz. Most fields are complete to about 6mJy peak flux density at 1.4GHz and to about 3mJy at 2.4GHz. The positions, peak and integral flux densities of 113 compact (<54") sources detected at 1.4GHz and of 70 sources (<34") detected at 2.4GHz are presented. Positions are accurate to about 3" and peak flux densities are accurate to about 10% or better, depending on the source position relative to the pointing centers. 32 of the sources detected at 1.4GHz are coincident with H{alpha} objects in the catalogue of Davies, Elliot and Meaburn (1976MmRAS..81...89D); these are possibly intrinsic to the LMC. However, we suppose that most are background objects, since the number vs. flux agrees with predictions of extragalactic source counts from other surveys.
- ID:
- ivo://CDS.VizieR/J/A+A/610/A27
- Title:
- Compact radio sources in NGC 6334D to F
- Short Name:
- J/A+A/610/A27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The presence and properties of compact radio sources embedded in massive star forming regions can reveal important physical properties about these regions and the processes occurring within them. The NGC 6334 complex, a massive star forming region, has been studied extensively. Nevertheless, none of these studies has focused in its content in compact radio sources. Aims. Our goal here is to report on a systematic census of the compact radio sources toward NGC 6334, and their characteristics. This will be used to attempt to define their very nature. We used the VLA C band (4-8GHz) archive data with 0.36" (500AU) of spatial resolution and noise level of 50Jy/bm to carry out a systematic search for compact radio sources within NGC 6334. We also searched for infrared counterparts to provide some constraints on the nature of the detected radio sources. A total of 83 compact sources and three slightly resolved sources were detected. Most of them are here reported for the first time. We found that 29 of these 86 sources have infrared counterparts and three are highly variable. Region D contains 18 of these sources. The compact source toward the center, in projection, of region E is also detected. From statistical analyses, we suggest that the 83 reported compact sources are real and most of them are related to NGC 6334 itself. A stellar nature for 27 of them is confirmed by their IR emission. Compared with Orion, region D suffers a deficit of compact radio sources. The infrared nebulosities around two of the slightly resolved sources are suggested to be warm dust, and we argue that the associated radio sources trace free-free emission from ionized material. We confirm the thermal radio emission of the compact source in region E. However, its detection at infrared wavelengths implies that it is located in the foreground of the molecular cloud. Finally, three strongly variable sources are suggested to be magnetically active young stars.
