- ID:
- ivo://CDS.VizieR/J/AZh/77/499
- Title:
- Flux densities of 235 pulsars at 102.5MHz
- Short Name:
- J/AZh/77/499
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The flux densities of 235 mostly faint pulsars at 102.5MHz are presented. The observations were carried out on the very sensitive Large Phased Array of the Lebedev Institute of Physics in 1994-1998. The procedure used for the observations and data processing is described in detail, and estimates of probable errors, including the effect of interstellar scintillations, are given. The mean spectral indices at 102-408MHz for normal and millisecond pulsars are calculated and compared with information from higher frequency data. There is a deficit of pulsars at distances of less than 3 kpc.
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- ID:
- ivo://CDS.VizieR/J/AZh/83/241
- Title:
- Flux-density-complete sample of radio sources
- Short Name:
- J/AZh/83/241
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of observations of flux-density- complete sample of radio with the RATAN-600 radio telescope at 0.97, 2.3, 3.9, 7.7, 11.1, and 21.7GHz. The sample was extracted from the GB6 catalog (<VIII/40>) at 4.85GHz, and contains all the sources at declination zone 74-75{deg} (J2000) with flux densities S(4.85)>100mJy. We have obtained optical identifications for 67% of radio sources with flat spectra and 36% of those with normal spectra.
- 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.
- ID:
- ivo://CDS.VizieR/VIII/4
- Title:
- Fourth Cambridge Survey (4C)
- Short Name:
- VIII/4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Fourth Cambridge Radio Survey (4C) Catalogue contains all survey data from the papers of Pilkington and Scott (1965MmRAS..69..183P) and Gower, Scott and Wills (1967MmRAS..71...49G). These data result from a survey of radio sources between declinations -07 and +80 degrees using the large Cambridge interferometer at 178 MHz. The computerized catalog contains for each source the 4C number, 1950 position, measured flux density, accuracy class, galactic coordinates, and remarks. For some sources miscellaneous brief comments such as cross identifications to the 3C catalog or remarks on contamination from nearby sources are given at the ends of the data records. A flag (*) is included if there are additional remarks in the published catalog.
- ID:
- ivo://CDS.VizieR/J/ApJ/892/105
- Title:
- Fourth catalog of Fermi LAT-detected AGNs (4LAC)
- Short Name:
- J/ApJ/892/105
- Date:
- 17 Jan 2022 00:31:09
- Publisher:
- CDS
- Description:
- The fourth catalog of active galactic nuclei (AGNs) detected by the Fermi Gamma-ray Space Telescope Large Area Telescope (4LAC) between 2008 August 4 and 2016 August 2 contains 2863 objects located at high Galactic latitudes (|b|>10{deg}). It includes 85% more sources than the previous 3LAC catalog based on 4yr of data. AGNs represent at least 79% of the high-latitude sources in the fourth Fermi-Large Area Telescope Source Catalog (4FGL), which covers the energy range from 50MeV to 1TeV. In addition, 344 gamma-ray AGNs are found at low Galactic latitudes. Most of the 4LAC AGNs are blazars (98%), while the remainder are other types of AGNs. The blazar population consists of 24% Flat Spectrum Radio Quasars (FSRQs), 38% BL Lac-type objects, and 38% blazar candidates of unknown types (BCUs). On average, FSRQs display softer spectra and stronger variability in the gamma-ray band than BL Lacs do, confirming previous findings. All AGNs detected by ground-based atmospheric Cerenkov telescopes are also found in the 4LAC.
- ID:
- ivo://CDS.VizieR/J/AJ/131/1872
- Title:
- Fourth VLBA calibrator survey: VCS4
- Short Name:
- J/AJ/131/1872
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents the fourth extension to the VLBA Calibrator Survey, containing 258 new sources not previously observed with very long baseline interferometry (VLBI). This survey, based on three 24hr Very Long Baseline Array observing sessions, fills remaining areas on the sky above declination -40{deg} where the calibrator density is less than one source within a 4{deg} radius disk in any given direction. The share of these areas was reduced from 4.6% to 1.9%. Source positions were derived from astrometric analysis of group delays determined at 2.3 and 8.6GHz frequency bands using the Calc/Solve software package. The VCS4 catalog of source positions, plots of correlated flux density versus projected baseline length, contour plots, and fits files of naturally weighted CLEAN images, as well as calibrated visibility function files, are available online at http://vlbi.gsfc.nasa.gov/vcs4 .
- ID:
- ivo://CDS.VizieR/J/other/PASA/33.45
- Title:
- FRBCAT: The Fast Radio Burst (FRB) Catalog
- Short Name:
- J/other/PASA/33.
- Date:
- 06 Dec 2021 20:29:39
- Publisher:
- CDS
- Description:
- Here, we present a catalogue of known Fast Radio Burst sources in the form of an online catalogue, FRBCAT. The catalogue includes information about the instrumentation used for the observations for each detected burst, the measured quantities from each observation, and model-dependent quantities derived from observed quantities. To aid in consistent comparisons of burst properties such as width and signal-to-noise ratios, we have re-processed all the bursts for which we have access to the raw data, with software which we make available. The originally derived properties are also listed for comparison.
- ID:
- ivo://CDS.VizieR/J/ApJS/255/22
- Title:
- FRII radio sources dynamical models
- Short Name:
- J/ApJS/255/22
- Date:
- 03 Dec 2021 13:25:10
- Publisher:
- CDS
- Description:
- Dynamical evolution models of 361 extragalactic Fanaroff-Riley type II radio sources selected from the Cambridge 3CRR, 6CE, 5C6, and 5C7 Sky Surveys, as well as the Bologna B2, Green Bank GB, and GB2 Surveys, are presented. Their spectra, compiled mostly from the recent catalogs of radio sources and the available NASA/IPAC and Astrophysical Catalogs Support System databases, along with morphological characteristics of the sources determined from their radio maps, have been modeled using the DYNAGE algorithm and/or its extension (KDA EXT) for the hypothetical case of further evolution after the jet's termination. The best-fit models provide estimates of a number of important physical parameters of the sources, as (i) the jet power, (ii) the density distribution of the external gaseous medium surrounding the radio core and the jet propagating through it, (iii) the initial energy distribution of the relativistic particles accelerated at the shock fronts, and (iv) the age of the observed radio structure. Additionally, estimates of some derivative parameters are provided, e.g., the radio lobes' pressure, their longitudinal expansion velocity, the magnetic field strength, and the total energy deposited in the lobes. The observed spectra and their best-fit models are included. Finally, one of the useful applications of the above models is presented, namely a strong correlation between the ambient medium density and the rest-frame two-point spectral index available directly from the observed spectra.
- 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.
- ID:
- ivo://CDS.VizieR/VIII/100
- Title:
- GaLactic and Extragalactic All-sky MWA survey
- Short Name:
- VIII/100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the Murchison Widefield Array (MWA), the low-frequency Square Kilometre Array (SKA1 LOW) precursor located in Western Australia, we have completed the GaLactic and Extragalactic All-sky MWA (GLEAM) survey, and present the resulting extragalactic catalogue, utilising the first year of observations. The catalogue covers 24,402 square degrees, over declinations south of +30{deg} and Galactic latitudes outside 10{deg} of the Galactic plane, excluding some areas such as the Magellanic Clouds. It contains 307,456 radio sources with 20 separate flux density measurements across 72-231MHz, selected from a time- and frequency- integrated image centred at 200MHz, with a resolution of ~=2'. Over the catalogued region, we estimate that the catalogue is 90% complete at 170mJy, and 50% complete at 55mJy, and large areas are complete at even lower flux density levels. Its reliability is 99.97% above the detection threshold of 5{sigma}, which itself is typically 50mJy. These observations constitute the widest fractional bandwidth and largest sky area survey at radio frequencies to date, and calibrate the low frequency flux density scale of the southern sky to better than 10%. This paper presents details of the flagging, imaging, mosaicking, and source extraction/characterisation, as well as estimates of the completeness and reliability. All source measurements and images are available online. This is the first in a series of publications describing the GLEAM survey results.
