- ID:
- ivo://CDS.VizieR/J/ApJS/222/12
- Title:
- Luminous X-ray candidates within D25 of galaxies
- Short Name:
- J/ApJS/222/12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using Chandra archive data we conduct a thorough survey of luminous X-ray sources. We directly analyze about 9400 ACIS Observations and cross-correlate the X-ray sources with 77000 galaxies within 250Mpc. The final catalog includes 119 unique luminous X-ray source candidates with L_X_>3x10^40^erg/s from 93 galaxies or 41 HLX candidates with L_X_>1x10^41^erg/s from 35 galaxies. We derive a moderate contamination rate due to foreground or background sources. We also cross-correlate the catalog with FIRST, perform variability and periodicity tests, and analyze one HLX candidate in particular. Our catalog could be a starting point to perform follow-up observations.
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- ID:
- ivo://CDS.VizieR/J/A+AS/80/215
- Title:
- Lunar occultations of weak radio sources
- Short Name:
- J/A+AS/80/215
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains the results of lunar occultation observations of 106 radio sources within declination +/- 19 degrees at 327 MHz. There are 171 sources listed in the catalog due to multiple components for some of the radio sources. Flux densities were measured at 327 MHz by lunar occultation with the Ooty Telescope. Flux densities have also been measured at 18 cm (1669 MHz) and 21 cm (1413 MHz) using the Nancay telescope. Optical identifications on the basis of the radio positions and angular structures are given. This catalog is a merge of table 1 and table 2 from the publication.
- ID:
- ivo://CDS.VizieR/J/A+A/630/A77
- Title:
- Lyra system LoFAR and XMM images
- Short Name:
- J/A+A/630/A77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Diffuse radio emission associated with the intra-cluster medium (ICM) is observed in a number of merging galaxy clusters. It is currently believed that in mergers a fraction of the kinetic energy is channeled into non-thermal components, such as turbulence, cosmic rays and magnetic fields, that may lead to the formation of giant synchrotron sources in the ICM. Studying merging galaxy clusters in different evolutionary phases is fundamental to understanding the origin of radio emission in the ICM. We observed the nearby galaxy cluster pair RXC J1825.3+3026 (z~0.065) and CIZA J1824.1+3029 (z~0.071) at 120-168MHz with the LOw Frequency ARray (LOFAR) and made use of a deep (240 ks) XMM-Newton dataset to study the nonthermal and thermal properties of the system. RXC J1825.3+3026 is in a complex dynamical state, with a primary on-going merger in the E-W direction and a secondary later stage merger with a group of galaxies in the SW, while CIZA J1824.1+3029 is dynamically relaxed. These two clusters are in a pre-merger phase. We report the discovery of a Mpc-scale radio halo with a low surface brightness extension in RXC J1825.3+3026 that follows the X-ray emission from the cluster center to the remnant of a galaxy group in the SW. This is among the least massive systems and the faintest giant radio halo known to date. Contrary to this, no diffuse radio emission is observed in CIZA J1824.1+3029 nor in the region between the pre-merger cluster pair. The power spectra of the X-ray surface brightness fluctuations of RXC J1825.3+3026 and CIZA J1824.1+3029 are in agreement with the findings for clusters exhibiting a radio halo and the ones where no radio emission has been detected, respectively. We provide quantitative support to the idea that cluster mergers play a crucial role in the generation of non-thermal components in the ICM.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A2
- Title:
- MACS J0717.5+3745 polarization int. maps
- Short Name:
- J/A+A/657/A2
- Date:
- 21 Mar 2022 09:20:37
- Publisher:
- CDS
- Description:
- We present wideband (1-6.5 GHz) polarimetric observations, obtained with the Karl G. Jansky Very Large Array (VLA), of the merging galaxy cluster MACS J0717.5+3745, which hosts one of the most complex known radio relic and halo systems. We use both Rotation Measure Synthesis and QU-fitting, and find a reasonable agreement of the results obtained with these methods, in particular, when the Faraday distribution is simple and the depolarization is mild. The relic is highly polarized over its entire length (850kpc), reaching a fractional polarization >30% in some regions. We also observe a strong wavelength-dependent depolarization for some regions of the relic. The northern part of the relic shows a complex Faraday distribution suggesting that this region is located in or behind the intracluster medium (ICM). Conversely, the southern part of the relic shows a Rotation Measure very close to the Galactic foreground, with a rather low Faraday dispersion, indicating very little magnetoionic material intervening the line-of-sight. From spatially resolved polarization analysis, we find that the scatter of Faraday depths correlates with the depolarization, indicating that the tangled magnetic field in the ICM causes the depolarization. We conclude that the ICM magnetic field could be highly turbulent. At the position of a well known narrow-angle-tailed galaxy (NAT), we find evidence of two components clearly separated in Faraday space. The high Faraday dispersion component seems to be associated with the NAT, suggesting the NAT is embedded in the ICM while the southern part of the relic lies in front of it. If true, this implies that the relic and this radio galaxy are not necessarily physically connected and thus, the relic may be not powered by the shock re-acceleration of fossil electrons from the NAT. The magnetic field orientation follows the relic structure indicating a well-ordered magnetic field. We also detect polarized emission in the halo region; however the absence of significant Faraday rotation and a low value of Faraday dispersion suggests the polarized emission, previously considered as the part of the halo, has a shock(s) origin.
- ID:
- ivo://CDS.VizieR/J/AZh/94/598
- Title:
- Magnetic fields of radio pulsars
- Short Name:
- J/AZh/94/598
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The mechanism of magnetodipole braking of radio pulsars is used to calculate new values of the surface magnetic fields of neutron stars. The angles {beta} between the spin axes and magnetic moments of the neutron stars were estimated for 376 radio pulsars using three different methods. It is shown that small inclinations of magnetic axes dominate. The equatorial magnetic fields for the considered sample of pulsars are calculated using the {beta} values obtained. As a rule, these magnetic fields are a factor of a few higher than the corresponding values in known catalogs.
- ID:
- ivo://CDS.VizieR/J/ApJ/606/664
- Title:
- MAMBO sources near NTT Deep Field
- Short Name:
- J/ApJ/606/664
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We discuss identifications for 18 sources from our Max-Planck- Millimeter-Bolometer (MAMBO) 1.2mm survey of the region surrounding the NTT Deep Field. We have obtained accurate positions from Very Large Array 1.4GHz interferometry, and in a few cases IRAM millimeter interferometry, and have also made deep BVRIzJK imaging at ESO.
- ID:
- ivo://CDS.VizieR/J/ApJ/901/159
- Title:
- MaNGA AGNs from WISE, Swift/BAT, NVSS & FIRST
- Short Name:
- J/ApJ/901/159
- Date:
- 21 Feb 2022 13:46:21
- Publisher:
- CDS
- Description:
- Accurate active galactic nucleus (AGN) identifications and spatially resolved host galaxy properties are a powerful combination for studies of the role of AGNs and AGN feedback in the coevolution of galaxies and their central supermassive black holes. Here, we present robust identifications of 406 AGNs in the first 6261 galaxies observed by the integral field spectroscopy survey Mapping Nearby Galaxies at Apache Point Observatory (MaNGA). Instead of using optical line flux ratios, which can be difficult to interpret in light of the effects of shocks and metallicity, we identify the AGNs via mid-infrared Wide-field Infrared Survey Explorer colors, Swift/BAT ultrahard X-ray detections, NVSS and FIRST radio observations, and broad emission lines in SDSS spectra. We subdivide the AGNs into radio-quiet and radio-mode AGNs, and examine the correlations of the AGN classes with host galaxy star formation rates and stellar populations. When compared to the radio-quiet AGN host galaxies, we find that the radio-mode AGN host galaxies are preferentially elliptical, lie further beneath the star-forming main sequence (with lower star formation rates at fixed galaxy mass), have older stellar populations, and have more negative stellar age gradients with galactocentric distance (indicating inside-out quenching of star formation). These results establish a connection between radio-mode AGNs and the suppression of star formation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/412/223
- Title:
- MASH PNe detected in large-scale radio surveys
- Short Name:
- J/MNRAS/412/223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an updated and newly compiled radio-continuum data base for Macquarie/AAO/Strasbourg H{alpha} (MASH) planetary nebulae (PNe) detected in the extant large-scale 'blind' radio-continuum surveys [NRAO VLA Sky Survey (NVSS), Sydney University Molonglo Sky Survey/Molonglo Galactic Plane Surveys (SUMSS/MGPS-2) and Parkes-MIT-NRAO (PMN)] and, for a small number of MASH PNe, observed and detected in targeted radio-continuum observations. We found radio counterparts for approximately 250 MASH PNe. In comparison with the percentage of previously known Galactic PNe detected in the NVSS and MGPS-2 radio-continuum surveys and according to their position on the flux density angular diameter and the radio brightness temperature evolutionary diagrams we conclude, unsurprisingly, that the MASH sample presents the radio-faint end of the known Galactic PNe population. Also, we present radio-continuum spectral properties of a small sub-sample of MASH PNe located in the strip between declinations -30{deg} and -40{deg}, that are detected in both the NVSS and MGPS-2 radio surveys.
- ID:
- ivo://CDS.VizieR/J/ApJ/767/14
- Title:
- MASIV survey III. Optical identifications
- Short Name:
- J/ApJ/767/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Intraday variability (IDV) of the radio emission from active galactic nuclei is now known to be predominantly due to interstellar scintillation (ISS). The MASIV (The Micro-Arcsecond Scintillation-Induced Variability) survey of 443 flat spectrum sources revealed that the IDV is related to the radio flux density and redshift. A study of the physical properties of these sources has been severely handicapped by the absence of reliable redshift measurements for many of these objects. This paper presents 79 new redshifts and a critical evaluation of 233 redshifts obtained from the literature. We classify spectroscopic identifications based on emission line properties, finding that 78% of the sources have broad emission lines and are mainly FSRQs. About 16% are weak lined objects, chiefly BL Lacs, and the remaining 6% are narrow line objects. The gross properties (redshift, spectroscopic class) of the MASIV sample are similar to those of other blazar surveys. However, the extreme compactness implied by ISS favors FSRQs and BL Lacs in the MASIV sample as these are the most compact object classes. We confirm that the level of IDV depends on the 5GHz flux density for all optical spectral types. We find that BL Lac objects tend to be more variable than broad line quasars. The level of ISS decreases substantially above a redshift of about two. The decrease is found to be generally consistent with ISS expected for beamed emission from a jet that is limited to a fixed maximum brightness temperature in the source rest frame.
- ID:
- ivo://CDS.VizieR/J/MNRAS/474/4396
- Title:
- MASIV Survey. IV. Radio AGNs variability
- Short Name:
- J/MNRAS/474/4396
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the relationship between 5GHz interstellar scintillation (ISS) and 15GHz intrinsic variability of compact, radio-selected active galactic nuclei (AGNs) drawn from the Microarcsecond Scintillation-Induced Variability (MASIV) Survey and the Owens Valley Radio Observatory blazar monitoring program. We discover that the strongest scintillators at 5GHz (modulation index, m_5_>=0.02) all exhibit strong 15GHz intrinsic variability (m_15_>=0.1). This relationship can be attributed mainly to the mutual dependence of intrinsic variability and ISS amplitudes on radio core compactness at ~100{mu}s scales, and to a lesser extent, on their mutual dependences on source flux density, arcsec-scale core dominance and redshift. However, not all sources displaying strong intrinsic variations show high amplitude scintillation, since ISS is also strongly dependent on Galactic line-of-sight scattering properties. This observed relationship between intrinsic variability and ISS highlights the importance of optimizing the observing frequency, cadence, timespan and sky coverage of future radio variability surveys, such that these two effects can be better distinguished to study the underlying physics. For the full MASIV sample, we find that Fermi-detected gamma-ray loud sources exhibit significantly higher 5GHz ISS amplitudes than gamma-ray quiet sources. This relationship is weaker than the known correlation between gamma-ray loudness and the 15GHz variability amplitudes, most likely due to jet opacity effects.
