- ID:
- ivo://CDS.VizieR/J/A+A/593/A47
- Title:
- Pinpointing the SMBH in NGC1052
- Short Name:
- J/A+A/593/A47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Supermassive black holes (SMBH) are essential for the production of jets in radio-loud active galactic nuclei (AGN). Theoretical models based on Blandford & Znajek (1977MNRAS.179..433B) extract the rotational energy from a Kerr black hole, which could be the case for NGC1052, to launch these jets. This requires magnetic fields on the order of 1000G to 10000G. We imaged the vicinity of the SMBH of the AGN NGC1052 with the Global Millimetre VLBI Array and found a bright and compact central feature that is smaller than 1.9 light days (100 Schwarzschild radii) in radius. Interpreting this as a blend of the unresolved jet bases, we derive the magnetic field at 1 Schwarzschild radius to lie between 200G and ~83000G consistent with Blandford & Znajek (1977MNRAS.179..433B) models.
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- ID:
- ivo://CDS.VizieR/J/A+A/632/A66
- Title:
- PKS 1549-79 ALMA data cubes & continuum images
- Short Name:
- J/A+A/632/A66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CO(1-0) and CO(3-2) Atacama Large Millimeter/submillimeter Array observations of the molecular gas in PKS 1549-79, as well as mm and very long baseline interferometry 2.3-GHz continuum observations of its radio jet. PKS 1549-79 is one of the closest young, radio-loud quasars caught in an on-going merger in which the active galactic nucleus (AGN) is in the first phases of its evolution. We detect three structures tracing the accretion and the outflow of molecular gas: kpc-scale tails of gas accreting onto PKS1549-79 from a merger, a circumnuclear disc in the inner few hundred parsec, and a very broad (>2300km/s) component detected in CO(1-0) at the position of the AGN. Thus, in PKS 1549-79 we see the co-existence of accretion and the ejection of gas. The line ratio CO(3-2)/CO(1-0) suggests that the gas in the circumnuclear-disc has both high densities and high kinetic temperatures. We estimate a mass outflow rate of at least 650M_{sun}_/yr. This massive outflow is confined to the inner region (r<120pc) of the galaxy, which suggests that the AGN drives the outflow. Considering the amount of molecular gas available in the central nuclear disc and the observed outflow rate, we estimate a time scale of 10^5^yr over which the AGN would be able to destroy the circumnuclear disc, although gas from the merger may come in from larger radii, rebuilding this disc at the same time. The AGN appears to self-regulate gas accretion to the centre and onto the super-massive black hole. Surprisingly, from a comparison with Hubble Space Telescope data, we find that the ionised gas outflow is more extended. Nevertheless, the warm outflow is about two orders of magnitude less massive than the molecular outflow. PKS 1549-79 does not seem to follow the scaling relation between bolometric luminosity and the relative importance of warm ionised and molecular outflows claimed to exist for other AGN. We argue that, although PKS 1549-79 hosts a powerful quasar nucleus and an ultra-fast outflow, the radio jet plays a significant role in producing the outflow, which creates a cocoon of disturbed gas that expands into the circumnuclear disc.
- ID:
- ivo://CDS.VizieR/J/A+A/634/A9
- Title:
- PKS 1549-79 ALMA data cubes & continuum images
- Short Name:
- J/A+A/634/A9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new observations of Fornax A taken at ~1GHz with the MeerKAT telescope and at ~6GHz with the Sardinia Radio Telescope (SRT). The sensitive (noise ~16uJy/beam), high-resolution (<10'') MeerKAT images show that the lobes of Fornax A have a double-shell morphology, where dense filaments are embedded in a diffuse and extended cocoon. We study the spectral properties of these components by combining the MeerKAT and SRT observations with archival data between 84MHz and 217GHz. For the first time, we show that multiple episodes of nuclear activity must have formed the extended radio lobes. The modelling of the radio spectrum suggests that the last episode of injection of relativistic particles into the lobes started ~24Myr ago and stopped 12Myr ago. More recently (~3Myr ago), a less powerful and short (<1Myr) phase of nuclear activity generated the central jets. Currently, the core may be in a new active phase. It appears that Fornax A is rapidly flickering. The dense environment around Fornax A has lead to a complex recent merger history for this galaxy, including mergers spanning a range of gas contents and mass ratios, as shown by the analysis of the galaxy's stellar- and cold-gas phases. This complex recent history may be the cause of the rapid, recurrent nuclear activity of Fornax A.
- ID:
- ivo://CDS.VizieR/J/A+A/586/A60
- Title:
- PKS 1502+106 15, 43 and 86GHz images
- Short Name:
- J/A+A/586/A60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Blazars are among the most energetic objects in the Universe. In 2008 August, Fermi/LAT detected the blazar PKS 1502+106, which showed a rapid and strong gamma-ray outburst followed by high and variable flux over the next months. This activity at high energies triggered an intensive multi-wavelength campaign that also covered the radio, optical, UV, and X-ray bands, indicating that the flare was accompanied by a simultaneous outburst at optical/UV/X-rays and a delayed outburst at radio bands. We explore the phenomenology and physical conditions within the ultra-relativistic jet of the gamma-ray blazar PKS 1502+106. Additionally, we address the question of the spatial localization of the MeV/GeV-emitting region of the source. We used ultra-high angular resolution mm-VLBI observations at 43 and 86GHz complemented by VLBI observations at 15GHz. We also employed single-dish radio data from the F-GAMMA program at frequencies matching the VLBI monitoring. PKS 1502+106 shows a compact core-jet morphology and fast superluminal motion with apparent speeds in the range 5-22c. Estimating Doppler factors along the jet yields values of between ~7 up to ~50. This Doppler factor gradient implies an accelerating jet. The viewing angle towards the source differs between the inner and outer jet, with the former at {theta}~3{deg} and the latter at {theta}~1{deg}, after the jet bends towards the observer beyond 1mas. The de-projected opening angle of the ultra-fast magnetically dominated jet is found to be (3.8+/-0.5){deg}. A single jet component can be associated with the pronounced flare both at high energies and in radio bands. Finally, the gamma-ray emission region is localized at <=5.9pc away from the jet base.
- ID:
- ivo://CDS.VizieR/J/MNRAS/455/3249
- Title:
- Planck-ATCA Co-eval Observations project
- Short Name:
- J/MNRAS/455/3249
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Planck-ATCA Co-eval Observations (PACO) project has yielded observations of 464 sources with the Australia Telescope Compact Array (ATCA) between 4.5 and 40GHz. The main purpose of the project was to investigate the spectral properties of mm-selected radio sources at frequencies below and overlapping with the ESA's Planck satellite frequency bands, minimizing the variability effects by observing almost simultaneously with the first two Planck all-sky surveys. In this paper we present the whole catalogue of observations in total intensity. By comparing PACO with the various measures of Planck Catalog of Compact Sources (PCCS) flux densities we found the best consistency with the PCCS 'detection pipeline' photometry (DETFLUX) that we used to investigate the spectral properties of sources from 5 to 217GHz. Of our sources, 91 percent have remarkably smooth spectrum, well described by a double power-law over the full range. This suggests a single emitting region, at variance with the notion that `flat' spectra result from the superposition of the emissions from different compact regions, self-absorbed up to different frequencies. Most of the objects show a spectral steepening above =~30GHz, consistent with synchrotron emission becoming optically thin. Thus, the classical dichotomy between flat-spectrum/compact and steep-spectrum/extended radio sources, well established at cm wavelengths, breaks down at mm wavelengths. The mm-wave spectra do not show indications of the spectral break expected as the effect of `electron ageing', suggesting young source ages.
- ID:
- ivo://CDS.VizieR/J/A+A/619/A94
- Title:
- Planck Multi-frequency Cat. of Non-thermal Sources
- Short Name:
- J/A+A/619/A94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents the Planck Multi-frequency Catalogue of Non-thermal (i.e. synchrotron-dominated) Sources (PCNT) observed between 30 and 857GHz by the ESA Planck mission. This catalogue was constructed by selecting objects detected in the full mission all-sky temperature maps at 30 and 143GHz, with a signal-to-noise ratio S/N>3 in at least one of the two channels after filtering with a particular Mexican hat wavelet. As a result, 29400 source candidates were selected. Then, a multi-frequency analysis was performed using the Matrix Filters methodology at the position of these objects, and flux densities and errors were calculated for all of them in the nine Planck channels. This catalogue was built using a different methodology than the one adopted for the Planck Catalogue of Compact Sources (PCCS) and the Second Planck Catalogue of Compact Sources (PCCS2), although the initial detection was done with the same pipeline that was used to produce them. The present catalogue is the first unbiased, full-sky catalogue of synchrotron-dominated sources published at millimetre and submillimetre wavelengths and constitutes a powerful database for statistical studies of non-thermal extragalactic sources, whose emission is dominated by the central active galactic nucleus. Together with the full multi-frequency catalogue, we also define the Bright Planck Multi-frequency Catalogue of Non-thermal Sources (PCNTb), where only those objects with a S/N>4 at both 30 and 143GHz were selected. In this catalogue 1146 compact sources are detected outside the adopted Planck GAL070 mask; thus, these sources constitute a highly reliable sample of extragalactic radio sources. We also flag the high-significance subsample (PCNThs), a subset of 151 sources that are detected with S/N>4 in all nine Planck channels, 75 of which are found outside the Planck mask adopted here. The remaining 76 sources inside the Galactic mask are very likely Galactic objects
- ID:
- ivo://CDS.VizieR/J/MNRAS/436/2915
- Title:
- Polarization of bright AT20G sources
- Short Name:
- J/MNRAS/436/2915
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present polarization data for 180 extragalactic sources extracted from the Australia Telescope 20GHz (AT20G) survey catalogue and observed with the Australia Telescope Compact Array during a dedicated, high sensitivity run ({sigma}_P_~1mJy). For the sake of completeness, we extracted the polarization information for seven extended sources from the 9yr Wilkinson Microwave Anisotropy Probe co-added maps at 23GHz. The full sample of 187 sources constitutes a =~99% complete sample of extragalactic sources brighter than S_20GHz_=500mJy at the selection epoch with declination {delta}<-30{deg}. The sample has a 91.4% detection rate in polarization at ~20GHz (94 percent if considering the subsample of point-like sources). We have measurements also at 4.8 and 8.6GHz within ~1 month of the 20GHz observations for 172 sources to reconstruct the spectral properties of the sample in total intensity and in polarization: 143 of them have a polarization detection at all three frequencies. We find that there is no statistically significant evidence of a relationship either between the fraction of polarization and frequency or between the fraction of polarization and the total intensity flux density. This indicates that Faraday depolarization is not very important above 4.8GHz and that the magnetic field is not substantially more ordered in the regions dominating the emission at higher frequencies (up to 20GHz). We estimate the distribution of the polarization fraction and the polarized flux density source counts at ~20GHz.
- ID:
- ivo://CDS.VizieR/VII/6
- Title:
- Polarization of Extragalactic Radio Sources
- Short Name:
- VII/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog contains 510 extragalactic radio sources, and covers all polarization measurements from 1965 to the middle of 1974 and a few other radio and optical data for these sources. The typical observation error was in the range of 1-2 percent in 1965 and 0.5-1 percent in 1974. The selection criterion for sources was that polarization data should be available at least at three wavelengths for each source. This reduced the sample to 510 sources. The catalog includes observational data: classifications, Cambridge numbers, coordinates, degrees of polarization at various wavelengths, polarization angles at each wavelength, largest angular diameters, position angles, and redshifts. The catalog also includes derived data: rotation measures, linear source diameters, polarization angles at wavelength 0 cm, differences between position angle and polarization angle at 0 cm, spectral indices between each pair of successive wavelengths observed, and polarization indices between each pair of successive wavelengths observed.
- ID:
- ivo://CDS.VizieR/J/ApJ/733/69
- Title:
- Polarized DRAO sources
- Short Name:
- J/ApJ/733/69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Dominion Radio Astrophysical Observatory Deep Field polarization study has been matched with the Spitzer Wide-Area Infrared Extragalactic Survey of the European Large Area Infrared Space Observatory Survey North 1 field. We have used Very Large Array observations with a total intensity rms of 87uJy/beam to match SWIRE counterparts to the radio sources. Infrared color analysis of our radio sample shows that the majority of polarized sources are elliptical galaxies with an embedded active galactic nucleus. Using available redshift catalogs, we found 429 radio sources of which 69 are polarized with redshifts in the range of 0.04<z<3.2. We find no correlation between redshift and percentage polarization for our sample. However, for polarized radio sources, we find a weak correlation between increasing percentage polarization and decreasing luminosity.
- ID:
- ivo://CDS.VizieR/J/A+A/374/861
- Title:
- Positions of giant radio galaxies
- Short Name:
- J/A+A/374/861
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In tablea1.dat, we present the WENSS selected candidate GRGs after removing sources identified as non-GRGs on basis of optical data. In tablea2.dat, we present the log of the spectroscopic observations of GRG andidates in our sample. In tablea3.dat, we present properties of the radio cores and the optical identifications of the spectroscopically observed giant radio sources, and of the confirmed giant sources B1144+352, B1245+676 and B1310+451. We provide the name of the radio source in IAU notation, the observation used to determine the radio core position and its flux density and the radio core position in right ascension and declination, respectively, in B1950.0 coordinates. The radio positions have been obtained by fitting a Gaussian in the radio map. We further provide the integrated flux density at 1.4GHz of the radio core, the position of the optical identification in right ascension and declination, respectively, in B1950.0 coordinates, obtained from fitting a Gaussian in the available optical image and the magnitude of the identification in the red (POSS-E) band of the Palomar survey. The magnitudes for sources weaker than 15.0 have been obtained from the APM catalogue and are estimated to be accurate to 0.5 mag. For brighter sources, we have measured the magnitudes directly from the digitized POSS-I frames using the photometric calibration for stars available from the STScI WWW-pages and through the getimage-2.0 plate retrieval software. Typical uncertainties in these values are estimated to be large, at least 1mag. In tablea4.dat, further radio properties of the sources in tablea3.dat. We present the integrated flux density of the source at 325MHz from the Westerbork Northern Sky Survey (WENSS) (unless stated otherwise), the integrated flux density at 1400MHz from the NVSS, the spectral index between 325 and 1400MHz, the redshift of the host galaxy, the angular size of the radio source in arcminutes, the resulting projected linear size in Mpc (using H_0=50km/s/Mpc, q_0_=0.5) and the radio luminosity at an emitted frequency of 325MHz.
