We present the measurements of Faraday rotation for 477 pulsars observed by the Parkes 64m radio telescope and the Green Bank 100m radio telescope. Using these results, along with previous measurements for pulsars and extragalactic sources, we analyze the structure of the large-scale magnetic field in the Galactic disk. Comparisons of rotation measures of pulsars in the disk at different distances, as well as with rotation measures of background radio sources beyond the disk, reveal large-scale reversals of the field directions between the spiral arms and interarm regions. We develop a model for the disk magnetic field, which can reproduce not only these reversals but also the distribution of the observed rotation measures of background sources.
Table1 gives the NVSS radio sources around the positions of all known pulsars. This table was generated by searching NVSS catalog, and each row gives the closest source around one pulsar. However, not all of them are pulsars, as we discussed in our paper. If there is "?" in the Notes, we had more considerations to identify the source as a pulsar. If there is nothing or just "*" in Notes, the source is believed to be the pulsar. Table 2 lists 14 strong pulsars not detected by the NVSS, or more exactly saying, not listed in the NVSS catalog. By the courtesy of Jim Condon, we found some of these pulsars are confused by nearby strong radio sources, and most of them were really scintillating during the NVSS.
For Seyfert galaxies, the AGN unification model provides a simple and well-established explanation of the type 1/type 2 dichotomy through orientation-based effects. The generalization of this unification model to the higher luminosity AGNs that quasars are remains a key question. The recent detection of type 2 radio-quiet quasars seems to support such an extension. We propose a further test of this scenario. On the basis of a compilation of quasar host-galaxy position angles consisting of previously published data and of new measurements performed using HST Archive images, we investigate the possible existence of a correlation between the linear polarization position angle and the host-galaxy/extended emission position angle of quasars.
Table 2 contains optical (V) polarimetric measurements for 42 optically selected QSOs including 29 broad absorption line QSOs. Table 3 contains a series of spectral indices characterizing the broad absorption line QSOs.
We present multi-frequency radio data for 741 extragalactic sources with a 5GHz integrated flux density of >100mJy. These sources have been selected from a cross-correlation of an early ROSAT All-Sky Survey source list with a list of compact radio sources of the 5GHz Green Bank northern sky survey (RGB sample, Cat. <VIII/52>). The majority of sources were quasi-simultaneously observed with the Effelsberg 100-m telescope at 11cm, 6cm, and 2.8cm. We have determined the spectrum, size and linear polarization properties of these sources. We compare the radio data with ROSAT measurements and optical data. We find that the X-ray selected radio sources, when compared with unbiased radio source samples, are on average slightly more compact, show a higher fractional polarization, a higher absolute rotation measure (RM), and have flatter spectra. Absolute RMs are larger for steep spectrum than for flat spectrum sources and for extended than for compact sources. The average redshift increases with the radio flux density, which indicates that the X-ray selected radio sources have a larger fraction of beamed radio emission. All source characteristics of the sample are in accordance with present unification schemes for AGN, where X-ray selected sources are preferably looked at face on.
We quantify the temporal behaviour of the optical polarisation fraction and angle for a selected sample of radio-loud NLSy1s. We also search for rotations of the polarisation plane similar to those commonly observed in blazars. The dataset was obtained with the RoboPol polarimeter of the Skinakas observatory as well as the KANATA, Perkins, and Steward observatories. We carried out numerical simulations to assess the probability that long rotations of the polarisation plane were caused by intrinsically evolving electric vector position angles (EVPAs) instead of observational noise. We conclude that it is much more likely that intrinsic rotations are responsible for the observed phenomenology.
We present multi-frequency VLA polarisation observations of compact steep spectrum (CSS) sources. About half of the sources are point-like even at the resolution of about 0.1x0.1 arcseconds. The remaining sources have double or triple structure. Low values for the percentage of polarised emission in CSS sources is confirmed. On the average, quasars are more polarised than galaxies. A wide range of RM values have been measured. There are clear indications of very large RMs up to about 5585rad/m^2^. CSS galaxies are characterized by RM values that are larger than CSS quasars. The majority of the objects show very large values of RM.
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.
A sample of 129 unresolved radio sources with ultrahigh linear polarization (>30%) has been selected from the NRAO VLA Sky Survey. Such high average linear polarization is unusual in extragalactic sources. Higher resolution Australia Telescope Compact Array and Very Large Array observations confirm the high average polarization but find that most of these sources are extended. The Sloan Digital Sky Survey spectroscopy, where available, shows that the optical counterparts are elliptical galaxies with no detectable emission lines. The optical spectra, radio luminosity, linear size and spectral index of these sources are typical of radio-loud active galactic nuclei.
