- ID:
- ivo://CDS.VizieR/J/AJ/124/1418
- Title:
- Radio-optical identification of star clusters
- Short Name:
- J/AJ/124/1418
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A reexamination of the correspondence between 6cm radio continuum sources and young star clusters in the Antennae galaxies indicates that ~85% of the strong thermal sources have optical counterparts, once the optical image is shifted 1.2" to the southwest. A sample of 37 radio-optical matches are studied in detail, showing correlations between radio properties (i.e., total flux and spectral index) and a variety of optical characteristics (i.e., intrinsic cluster brightness, H{alpha} flux and equivalent width, extinction, and cluster ages). There is a strong correlation between the radio flux and the intrinsic optical brightness.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/276/614
- Title:
- Radio-optical 151MHz survey of the N. Ecl. Cap
- Short Name:
- J/MNRAS/276/614
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Cambridge Low Frequency Synthesis Telescope has been used to survey a region ~7x7deg^2^ about the North Ecliptic Cap at 151MHz with a resolution of 70x77arcsec^2^. The resulting radio source catalogue of 400 sources is complete to a peak flux density limit of 120mJy/beam. Using the Cambridge APM we have searched for identifications on the Palomar Sky Survey plate 550 which covers much of the survey area, and we list the 157 sources with one or more optical objects within 15arcsec of the radio position.
- ID:
- ivo://CDS.VizieR/J/ApJ/439/983
- Title:
- Radio & optical observation of UX Arietis
- Short Name:
- J/ApJ/439/983
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have observed UX Arietis at C band (6cm) for 3 weeks with four VLA antennas. The temporal coverage during the program was approximately three scans per day. A few days into the VLA program, UX Ari began a radio flaring period which lasted for at least 2 weeks. All the radio fluxes were above the system noise during this episode, but the largest values (up to 270mJy) occurred close to 0.0 phase. This phasing is confirmed by the UX Ari radio observations of Neidhoefer, Massi, & Chiuderi-Drago (1993A&A...278L..51N). Visible-band light curves of UX Ari were obtained both during and after our radio observations; the peak-to-peak variation in all filters was ~0.2mag. The light curves indicate that the maximum starspot visibility occurred very close to 0.0 phase, the same phase as the radio maxima. Closer comparison of our radio and optical light curves indicates that they are almost perfectly anticorrelated. A similar radio/optical correlation has been found by Lim et al. (1992ApJ...388L..27L) and Lim et al. (1994ApJ...430..332L) for the single K0 V star AB Dor. We make the following conclusions from our observations. First, the episodes of long-term (~hours to days) radio flaring were modulated by stellar eclipses. Second, the flares were located close to the starspot groups. Third, the sizes of the flares were comparable to sizes of the starspot groups, which is consistent with nonthermal emission of brightness temperature T_b~10^10-10^13K. Fourth, the radio emission arose only from the midlatitude starspot groups. Last, the radio flares emitted their radiation nearly normal to the stellar surface.
- ID:
- ivo://CDS.VizieR/J/A+A/520/A62
- Title:
- Radio-optical scrutiny of compact AGN
- Short Name:
- J/A+A/520/A62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the correlations between the VLBA (Very Long Baseline Array) radio emission at 15GHz, extended emission at 151MHz, and optical nuclear emission at 5100{AA} for a complete sample of 135 compact jets. We use the partial Kendall's tau correlation analysis to check the link between radio properties of parsec-scale jets and optical nuclear luminosities of host active galactic nuclei (AGN).
- ID:
- ivo://CDS.VizieR/J/ApJ/666/201
- Title:
- Radio polarimetry of the ELAIS N1 field
- Short Name:
- J/ApJ/666/201
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep polarimetric observations at 1420MHz of the European Large Area ISO Survey North 1 region (ELAIS N1) as part of the Dominion Radio Astrophysical Observatory Planck Deep Fields project. By combining closely spaced aperture synthesis fields, we image a region of 7.43deg^2^ to a maximum sensitivity in Stokes Q and U of 78uJy/beam, and detect 786 compact sources in Stokes I. Of these, 83 exhibit polarized emission.
- ID:
- ivo://CDS.VizieR/J/MNRAS/401/1388
- Title:
- Radio polarization of WMAP point sources
- Short Name:
- J/MNRAS/401/1388
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations were conducted using the VLA in D-configuration between 01.40 and 19.30 UT on 2008 August 1.
- ID:
- ivo://CDS.VizieR/J/AJ/102/1663
- Title:
- Radio properties of extragal. IRAS sources
- Short Name:
- J/AJ/102/1663
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog presents radio and optical identifications of extragalactic IRAS sources from the IRAS Faint Source Catalog |b| > 50{deg} (Moshir et al., 1989 Cat. <II/156>). Sources with flux density > 0.2 at 60 microns and with S_60_ > S_12_ were identified by position coincidence with radio sources stronger than 25 mJy and lying north of declination = 5{deg} on the Green Bank 4.85 GHz sky map. Published VLA maps, new 4.86 GHz VLA maps made with 15 arcsec resolution, and accurate optical positions were used to confirm 122 candidate identifications. This catalog contains a merged version of tables 1 and 2 from the paper.
- ID:
- ivo://CDS.VizieR/J/A+A/560/A23
- Title:
- Radio properties of faint BL Lacs
- Short Name:
- J/A+A/560/A23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The advent of Fermi is changing our understanding on the radio and gamma-ray emission in Active Galactic Nuclei. Contrary to pre-Fermi ideas, BL Lac objects are found to be the most abundant emitters in the gamma-ray band. However, since they are relatively weak radio sources, most of their parsec-scale structure and their multi-frequency properties are poorly understood and/or have not been investigated in a systematically fashion. Our main goal is to analyze the radio and gamma-ray emission properties of a sample of 42 BL Lacs selected, for the first time in the literature, with no constraint on their radio and gamma-ray flux densities/emission. Thanks to new Very Long Baseline Array observations at 8 and 15GHz for the whole sample, we present here fundamental parameters such as radio flux densities, spectral index information, and parsec-scale structure. Moreover, we search for gamma-ray counterparts using data reported in the Second Catalog of Fermi Gamma-ray sources. Parsec-scale radio emission is observed in the majority of the sources at both frequencies. Gamma-ray counterparts are found for 14/42 sources. The comparison between our results in radio and gamma-ray bands points out the presence of a large number of faint BL Lacs showing "non classical" properties such as low source compactness, core dominance, no gamma-ray emission and steep radio spectral indexes. A deeper multiwavelength analysis will be needed.
- ID:
- ivo://CDS.VizieR/J/ApJ/445/62
- Title:
- Radio properties of optically selected quasars
- Short Name:
- J/ApJ/445/62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Approximately one-quarter (256 objects) of the Large Bright Quasar Survey (LBQS, Hewett et al., 1995, Cat. <J/AJ/109/1498>) has been observed with the VLA at 8.4GHz, resulting in 44 detections (17%) with a median 3{sigma} noise limit of 0.29mJy. Quasars with radio luminosity detectable at this limit are under-represented at faint absolute blue magnitudes (M_B_>=-24), an effect which cannot be explained by a potential LBQS selection bias against quasars which have large radio luminosities and small optical luminosities. The radio-loud (8GHz luminosity >10^25^W/Hz) fraction is observed to change as a function of redshift and MB, for M_B_<-24, although the causal variable is ambiguous. The description most consistent with the available data is that radio-loud fraction is approximately constant over the range -27.5<M_B_<-24 and increases at brighter absolute magnitudes. The radio-loud fraction as a function of redshift reaches a local maximum at z~1, and, aside from the effects of increased radio-loud fraction at bright M_B_, remains roughly constant to redshifts approaching 5. The log R_8.4_ distribution (radio-to-optical luminosity ratio) of the current LBQS sample may be bimodal, but the results of statistical tests are ambiguous, requiring a larger sample size to become definite.
- ID:
- ivo://CDS.VizieR/J/other/PPMtO/17B.1
- Title:
- Radio properties of ROSAT sources
- Short Name:
- J/other/PPMtO/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A cross-identification of the southern-sky objects with the ROSAT All-Sky Survey (Cat. <IX/10>) and Parkes-MIT-NRAO (PMN) Radio (5GHz) Survey (Cat. <VIII/38>) yields a list of 642 sources. Subsequential optical identification for all these coincidences has been taken to form a large sample of galaxies and Active Galactic Nuclei (AGNs). As a result, 311 (52%) were previously optically identified as extragalactic objects. The fluxes detected from X-ray, optical, and radio bands for them are compiled. This database allows an investigation on broad band energy distribution and other possible correlations among spectral indices and luminosities for various types of extragalactic objects.