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- ID:
- ivo://CDS.VizieR/J/A+A/433/757
- Title:
- Optical polarization of 203 QSOs
- Short Name:
- J/A+A/433/757
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This Table contains linear polarization measurements (mainly in the V band) of 203 QSOs. First time measurements have been obtained for 184 objects. Among them 109 known radio emitters, 42 BAL and 1 gravitationally lensed QSO.
- ID:
- ivo://CDS.VizieR/J/A+AS/101/551
- Title:
- Optical polarization of 1000 stars
- Short Name:
- J/A+AS/101/551
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have prepared a catalogue of optical polarization measurements for 1000 stars closer than 50 parsecs from the Sun. The distances, which are presently those given in the Sky Catalogue 2000.0, 2nd Edition (Hirshfeld et al., 1991skca.book.....H) are provisional: they will be replaced later by the much safer parallaxes which will result from the Hipparcos mission. The polarization data have been compiled, for 60% in various catalogues with due care to their accuracy; for 40% they are new, unpublished, measurements obtained at Pic du Midi Observatory. We expect that this new data base will allow a better understanding of the interstellar medium around the Sun.
- ID:
- ivo://CDS.VizieR/J/MNRAS/452/715
- Title:
- Optical polarization of the Polaris Flare
- Short Name:
- J/MNRAS/452/715
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The stages before the formation of stars in molecular clouds are poorly understood. Insights can be gained by studying the properties of quiescent clouds, such as their magnetic field structure. The plane-of-the-sky orientation of the field can be traced by polarized starlight. We present the first extended, wide-field (~10deg^2^) map of the Polaris Flare cloud in dust-absorption induced optical polarization of background stars, using the Robotic Polarimeter (RoboPol) polarimeter at the Skinakas Observatory. This is the first application of the wide-field imaging capabilities of RoboPol. The data were taken in the R band and analysed with the automated reduction pipeline of the instrument. We present in detail optimizations in the reduction pipeline specific to wide-field observations. Our analysis resulted in reliable measurements of 641 stars with median fractional linear polarization 1.3%. The projected magnetic field shows a large-scale ordered pattern. At high longitudes it appears to align with faint striations seen in the Herschel-Spectral and Photometric Imaging Receiver (SPIRE) map of dust emission (250um), while in the central 4.5 deg2 it shows an eddy-like feature. The overall polarization pattern we obtain is in good agreement with large-scale measurements by Planck of the dust emission polarization in the same area of the sky.
- ID:
- ivo://CDS.VizieR/J/MNRAS/493/L54
- Title:
- Optical polarization properties of AGNs
- Short Name:
- J/MNRAS/493/L54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Significant positional offsets of the value from 1 mas to more than 10mas were found previously between radio (VLBI) and optical (Gaia) positions of active galactic nuclei (AGNs). They happen preferentially parallel to the parsec-scale jet direction. AGNs with VLBI-to-Gaia offsets pointed downstream the jet are found to have favourably higher optical polarization, as expected if extended optical jets dominate in the emission and shift the Gaia centroid away from the physical nucleus of the source. Upstream offsets with the suggested domination of accretion discs manifest themselves through the observed low optical polarization. Direction of linear optical polarization is confirmed to preferentially align with parsec-scale jets in AGNs with dominant jets consistent with a toroidal magnetic field structure. Our findings support the disc-jet interpretation of the observed positional offsets. These results call on an intensification of AGN optical polarization monitoring programs in order to collect precious observational data. Taken together with the continued VLBI and Gaia observations, they will allow researchers to reconstruct detailed models of the disc-jet system in AGNs on parsec scales.
- ID:
- ivo://CDS.VizieR/J/MNRAS/465/4085
- Title:
- PACO radio sources complete sample polarimetry
- Short Name:
- J/MNRAS/465/4085
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-sensitivity polarimetric observations ({sigma}_P_~=0.6mJy) in six bands covering the 5.5-38GHz range of a complete sample of 53 compact extragalactic radio sources brighter than 200mJy at 20GHz. The observations, carried out with the Australia Telescope Compact Array, achieved a 91 per cent detection rate (at 5{sigma}). Within this frequency range, the spectra of about 95 per cent of sources are well fitted by double power laws, both in total intensity and in polarization, but the spectral shapes are generally different in the two cases. Most sources were classified as either steep- or peaked-spectrum but less than 50 per cent have the same classification in total and in polarized intensity. No significant trends of the polarization degree with flux density or with frequency were found. The mean variability index in total intensity of steep-spectrum sources increases with frequency for a 4-5yr lag, while no significant trend shows up for the other sources and for the 8yr lag. In polarization, the variability index, which could be computed only for the 8yr lag, is substantially higher than in total intensity and has no significant frequency dependence.
- ID:
- ivo://CDS.VizieR/J/AZh/78/60
- Title:
- Photometry and polarimetry of Ae star VV Ser
- Short Name:
- J/AZh/78/60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results of long-term photometric and polarimetric observations of the classical Herbig Ae star VV Ser, performed at the Crimean Astrophysical Observatory as part of a program of photometric and polarimetric monitoring of UX Ori stars are presented.
- ID:
- ivo://CDS.VizieR/J/A+A/327/145
- Title:
- Photopolarimetric activity of RR Tauri
- Short Name:
- J/A+A/327/145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of coordinated Crimea-Dodaira simultaneous multi-bands photometric and polarimetric observations of the classical Herbig Ae/Be star RR Tau which cover fully the observed interval of its brightness changes are presented. Within the observed interval of its light variations the linear polarization of RR Tau anti-correlates with its brightness changes.
- ID:
- ivo://CDS.VizieR/J/AZh/77/420
- Title:
- Photopolarimetric activity of SV Cep
- Short Name:
- J/AZh/77/420
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of the eleven-years (1987-98) photopolarimetric patrol observations of Herbig Ae star SV Cep are presented. Only one deep brightness minimum of star were observed during this time interval. The decrease of the SV Cep brightness during this minimum was accompanied by increase of its linear polarization. The similar behaviour of linear polarization with the brightness changes was found earlier in other young stars with the non-periodic Algol-type minima. The most probable interpretation of this phenomenon is based on the model in which the source of intrinsic linear polarization is the scattered radiation of circumstellar disk-like dust envelope (probably the proto-planetary disk). The deposition of this source increases during the brightness minima when the direct (non-polarized) stellar radiation are absorbed in the CS dust clouds intersected the line-of-sight.
- ID:
- ivo://CDS.VizieR/J/A+AS/112/457
- Title:
- Photopolarimetry of BM And
- Short Name:
- J/A+AS/112/457
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of photoelectric UBV observations of the T Tauri type variable BM And made during 1983-1991, as well as of simultaneous photopolarimetric UBVRI observations of this star for 1990-93 are given.
