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71. FIRST-Optical-VLA survey for lensed radio lobes
ID:
ivo://CDS.VizieR/J/AJ/130/1977
Title:
FIRST-Optical-VLA survey for lensed radio lobes
Short Name:
J/AJ/130/1977
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results from a survey for gravitationally lensed radio lobes. Lensed lobes are a potentially richer source of information about galaxy mass distributions than lensed point sources, which have been the exclusive focus of other recent surveys. Our approach is to identify radio lobes in the Faint Images of the Radio Sky at Twenty cm (FIRST, Cat. <VIII/71>) catalog and then search optical catalogs for coincident foreground galaxies, which are candidate lensing galaxies. We then obtain higher resolution images of these targets at both optical and radio wavelengths and obtain optical spectra for the most promising candidates. We present maps of several radio lobes that are nearly coincident with galaxies. We have not found any new and unambiguous cases of gravitational lensing. One radio lobe in particular, FOV J0743+1553, has two hot spots that could be multiple images produced by a z=0.19 spiral galaxy, but the lensing interpretation is problematic.
72. Flux densities for 290 blazars
ID:
ivo://CDS.VizieR/J/AN/338/700
Title:
Flux densities for 290 blazars
Short Name:
J/AN/338/700
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of nine years of the blazar observing programme at the RATAN-600 radio telescope (2005-2014). The data were obtained at six frequency bands (1.1, 2.3, 4.8, 7.7, 11.2, 21.7GHz) for 290 blazars, mostly BL Lacs. In addition, we used data at 37GHz obtained quasi-simultaneously with the Metsahovi radio observatory for some sources. For each source NVSS name (RA (hhmmss) and DEC (ddmmss) for the J2000.0 epoch), and flux densities at seven frequencies are presented (1.1-37GHz).
73. Fluxes of Faint Radio Sources at 2.7/4.75 GHz
ID:
ivo://CDS.VizieR/VIII/57
Title:
Fluxes of Faint Radio Sources at 2.7/4.75 GHz
Short Name:
VIII/57
Date:
21 Oct 2021
Publisher:
CDS
Description:
This table is a compilation of revised 4.75 GHz and 2.695 GHz flux densities and corresponding spectral indices at epoch 1986.2 of a catalog of 239 sources, which has previously been published by Forkert and Altschuler, (1987A&AS...70...77F). It comprises 209 sources (marked 'A'), forming a complete, flux density limited sample above 50 mJy at 4.76 GHz in 1981.9 (Altschuler, 1986A&AS...65..267A), and 30 sources (marked 'a') below this limit, but with 5.0 GHz flux densities from 1971.0 (Davis, 1971AJ.....76..980D). The catalogue covers a narrow strip of the sky around declination of 33 degrees. The flux densities were calibrated with 3C286 on the scale of Kellermann, Pauliny-Toth and Williams (1969ApJ...157....1K). After publication of the catalog a statistical analysis for flux density variability in the data has been performed (Forkert, 1990), using 6cm flux density measurements of Davis (1971AJ.....76..980D) and Altschuler (1986A&AS...65..267A) and the 2.695 GHz flux densities of Pauliny-Toth et al. (1974A&A....35..421P), the details and results of which are going to be published elsewhere (Altschuler & Forkert, in preparation). For the purposes of this analysis it has become necessary to obtain more individual error estimates of the 1986.2 data, not dominated by the effect of overall scale errors. This revision for some of the sources also led to slightly different flux densities from those previously published. The variability study proved the flux density errors to represent the individual 1-sigma uncertainties, WITHOUT the effect of overall scale errors. From the aforementioned comparison with other measurements scale errors of ~1% at 2.695 GHz and ~3% at 4.75 GHz seem likely.
74. Full-Stokes polarimetry of 5 radio sources
ID:
ivo://CDS.VizieR/J/A+A/609/A68
Title:
Full-Stokes polarimetry of 5 radio sources
Short Name:
J/A+A/609/A68
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an analysis pipeline that enables the recovery of reliable information for all four Stokes parameters with high accuracy. Its novelty relies on the effective treatment of the instrumental effects even before the computation of the Stokes parameters, contrary to conventionally used methods such as that based on the Mueller matrix. For instance, instrumental linear polarization is corrected across the whole telescope beam and significant Stokes Q and U can be recovered even when the recorded signals are severely corrupted by instrumental effects. The accuracy we reach in terms of polarization degree is of the order of 0.1-0.2%. The polarization angles are determined with an accuracy of almost 1{def}. The presented methodology was applied to recover the linear and circular polarization of around 150 active galactic nuclei, which were monitored between July 2010 and April 2016 with the Effelsberg 100-m telescope at 4.85GHz and 8.35GHz with a median cadence of 1.2 months. The polarized emission of the Moon was used to calibrate the polarization angle measurements. Our analysis showed a small system-induced rotation of about 1{deg} at both observing frequencies. Over the examined period, five sources have significant and stable linear polarization; three sources remain constantly linearly unpolarized; and a total of 11 sources have stable circular polarization degree m_c_, four of them with non-zero m_c_. We also identify eight sources that maintain a stable polarization angle. All this is provided to the community for future polarization observations reference. We finally show that our analysis method is conceptually different from those traditionally used and performs better than the Mueller matrix method. Although it has been developed for a system equipped with circularly polarized feeds, it can easily be generalized to systems with linearly polarized feeds as well.
75. Galactic Center 6 and 20cm survey
ID:
ivo://CDS.VizieR/J/ApJS/118/201
Title:
Galactic Center 6 and 20cm survey
Short Name:
J/ApJS/118/201
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used the VLA to survey 10 fields at 20 cm (1658MHz) and 11 fields at 6 cm (5GHz) that are between 7' and 137' from SgrA*. Our objective was to identify extragalactic sources and measure their scattering diameters so as to constrain the GC-scattering region separation. In order to find sources within these fields, we have employed pdfCLEAN, a source detection algorithm in which sources are identified in an image by comparing the intensity histogram of the image to that expected from a noise-only image. We found over 100 sources, with the faintest sources being approximately 3 mJy. The average number of sources per field is approximately 10, though fields close to SgrA* tend to contain fewer sources. A number of Galactic sources are included in our source catalog. The double-lobed source 1LC 359.872+0.178, potentially an X-ray quiet version of 1E 1740.7-2942, a shell-like structure with a central point source, and a possible radio transient, are discussed in the paper.
76. Galactic HII regions RRL and continuum data
ID:
ivo://CDS.VizieR/J/ApJ/738/27
Title:
Galactic HII regions RRL and continuum data
Short Name:
J/ApJ/738/27
Date:
21 Oct 2021
Publisher:
CDS
Description:
The distribution of metals in the Galaxy provides important information about galaxy formation and evolution. HII regions are the most luminous objects in the Milky Way at mid-infrared to radio wavelengths and can be seen across the entire Galactic disk. We used the National Radio Astronomy Observatory (NRAO) Green Bank Telescope to measure radio recombination line (RRL) and continuum emission in 81 Galactic HII regions. We calculated LTE electron temperatures using these data. In thermal equilibrium metal abundances are expected to set the nebular electron temperature with high abundances producing low temperatures. Our HII region distribution covers a large range of Galactocentric radius (5-22kpc) and samples the Galactic azimuth range 330-60{deg}. Using our highest quality data (72 objects) we derived an O/H Galactocentric radial gradient of -0.0383+/-0.0074dex/kpc. Combining these data with a similar survey made with the NRAO 140 Foot telescope we get a radial gradient of -0.0446+/-0.0049dex/kpc for this larger sample of 133 nebulae.
77. Galactic Worms
ID:
ivo://CDS.VizieR/J/ApJ/390/108
Title:
Galactic Worms
Short Name:
J/ApJ/390/108
Date:
21 Oct 2021
Publisher:
CDS
Description:
A catalog of candidates for the Galactic Worms that are possibly the walls surrounding the superbubbles is compiled; 118 isolated structures that appear both in HI and in IR (60 and 100{mu}m). 52 are possibly associated with HII regions. It is found that the 100-{mu}m emissivity increases systematically toward the Galactic interior, which is consistent with the increase of the general interstellar radiation field. The 100-{mu}m emissivity of the structures associated with the HII regions is larger than that of the structures without associated HII regions. The 60-100{mu}m ratio is large, 0.28+/-0.03, which may indicate that the grains associated with the atomic gas have a relatively large population of small grains. 35 structures appear in the 408MHz continuum. The IR and the radio continuum properties suggest that the 408MHz continuum emission in those structures is very likely thermal. The implications of these results on the ionization of gas far from the Galactic plane are discussed.
78. Galaxies in and near the cluster A1185
ID:
ivo://CDS.VizieR/J/AZh/76/83
Title:
Galaxies in and near the cluster A1185
Short Name:
J/AZh/76/83
Date:
21 Oct 2021
Publisher:
CDS
Description:
Results of optical, radio, and submillimeter studies of the nearby galaxy cluster A1185 are presented. Coordinates have been obtained for 115 galaxies that are either cluster members or field galaxies in the direction of A1185. Radio spectra for a number of galaxies in this cluster have been derived using observations on the RATAN-600 radio telescope at 2.7,3.9,7.6, and 31 cm, together with data published in other study. At the cluster center some of the galaxies have either flat or inverted spectra.
79. G29.96-0.02 and G35.20-1.74 1mm and 3mm maps
ID:
ivo://CDS.VizieR/J/A+A/530/A118
Title:
G29.96-0.02 and G35.20-1.74 1mm and 3mm maps
Short Name:
J/A+A/530/A118
Date:
21 Oct 2021
Publisher:
CDS
Description:
Most work on high-mass star formation has focused on observations of young massive stars in protoclusters. Very little is known about the preceding stage. Here, we present a new high-resolution study of pre-protocluster regions in tracers exclusively probing the coldest and dense gas (NH_2_ D). The two target regions G29.96-0.02 and G35.20-1.74 (W48) are drawn from the SCAMPS project, which searches for pre-protoclusters near known ultracompact HII regions. We used our data to constrain the chemical, thermal, kinematic, and physical conditions (i.e., densities) in G29.96e and G35.20w. NH_3_, NH_2_ D, HCO^+^, and continuum emission were mapped using the VLA, PdBI, and BIMA.
80. G346.056-0.021 and G346.077-0.056 radio images
ID:
ivo://CDS.VizieR/J/A+A/612/A36
Title:
G346.056-0.021 and G346.077-0.056 radio images
Short Name:
J/A+A/612/A36
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a multiwavelength study of two southern Galactic H II regions G346.056-0.021 and G346.077-0.056 which are located at a distance of 10.9kpc. The distribution of ionized gas, cold and warm dust, and the stellar population associated with the two H II regions are studied in detail using measurements at near-infrared, mid-infrared, far-infrared, submillimeter and radio wavelengths. The radio continuum maps at 1280 and 610MHz were obtained using the Giant Metrewave Radio Telescope to probe the ionized gas. The dust temperature, column density, and dust emissivity maps were generated using modified blackbody fits in the far-infrared wavelength range 160-500um. Various near- and mid-infrared color and magnitude criteria were adopted to identify candidate ionizing star(s) and the population of young stellar objects in the associated field. The radio maps reveal the presence of diffuse ionized emission displaying distinct cometary morphologies. The 1280MHz flux densities translate to ZAMS spectral types in the range O7.5V-O7V and O8.5V-O8V for the ionizing stars of G346.056-0.021 and G346.077-0.056, respectively. A few promising candidate ionizing star(s) are identified using near-infrared photometric data. The column density map shows the presence of a large, dense dust clump enveloping G346.077-0.056. The dust temperature map shows peaks towards the two HII regions. The submillimeter image shows the presence of two additional clumps, one being associated with G346.056-0.021. The masses of the clumps are estimated to range between ~1400 and 15250M_{sun}_. Based on simple analytic calculations and the correlation seen between the ionized gas distribution and the local density structure, the observed cometary morphology in the radio maps is better explained invoking the champagne-flow model.

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