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Related papers: Broad-band linear polarization in late-type active…

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We present a study of the linear polarization properties of radio sources within the 10 deg$^2$ Wide Chandra Deep Field South (W-CDFS) in S-band (2-4 GHz). Our W-CDFS image has an angular resolution of 15 arcsec and a 1$\sigma$ RMS in…

We measured mid-infrared polarization of protoplanetary discs to gain new insight into their magnetic fields. Using CanariCam at the 10.4 m Gran Telescopio Canarias, we detected linear polarization at 8.7, 10.3, and 12.5 $\mu$m from discs…

Earth and Planetary Astrophysics · Physics 2017-11-16 Dan Li , Charles M. Telesco , Han Zhang , Christopher M. Wright , Eric Pantin , Peter J. Barnes , Chris Packham

We discuss the polarization of broad emission lines in the type 1 active galactic nuclei (AGNs). The polarization depends on the geometry of the broad line region (BLR), and also on the polarization mechanism, or distribution of the…

Astrophysics of Galaxies · Physics 2021-11-12 L. C. Popović , E. Shablovinskaya , Dj. Savić

The polarization signatures of the blazar emissions are known to be highly variable. In addition to small fluctuations of the polarization angle around a mean value, sometimes large (> 180^o) polarization angle swings are observed. We…

High Energy Astrophysical Phenomena · Physics 2015-06-24 Haocheng Zhang , Xuhui Chen , Markus Boettcher , Fan Guo , Hui Li

Blazars are jetted active galactic nuclei, with the jet aligned along the observer's line of sight. Their spectral energy distributions are dominated by non-thermal emission, with an underlying thermal component at optical/ultraviolet…

High Energy Astrophysical Phenomena · Physics 2026-05-07 J. Barnard , B. van Soelen , I. P. van der Westhuizen , M. Böttcher , A. Martin-Carrillo , H. M. Schutte , S. van der Merwe , M. Zacharias

We present the results of a systematic observational campaign designed to search for microvariability in the optical polarization of BL Lac objects. We have observed a sample formed by 8 X-ray-selected and 10 radio-selected sources, looking…

Astrophysics · Physics 2009-11-11 I. Andruchow , G. E. Romero , S. A. Cellone

Frequency dependence of pulsar linear polarization is investigated by simulations of emission and propagation processes. Linearly polarized waves are generated through curvature radiation by relativistic particles streaming along curved…

High Energy Astrophysical Phenomena · Physics 2015-06-23 P. F. Wang , C. Wang , J. L. Han

We present deep polarimetric observations at 154 MHz with the Murchison Widefield Array (MWA), covering 625 deg^2 centered on RA=0 h, Dec=-27 deg. The sensitivity available in our deep observations allows an in-band, frequency-dependent…

The variable star AR Sco was recently discovered to pulse in brightness every 1.97 min from ultraviolet wavelengths into the radio regime. The system is composed of a cool, low-mass star in a tight, 3.55 hr orbit with a more massive white…

High Energy Astrophysical Phenomena · Physics 2017-01-26 D. A. H. Buckley , P. J. Meintjes , S. B. Potter , T. R. Marsh , B. T Gänsicke

Blazars are known for their energetic multiwavelength flares from radio wavelengths to high-energy $\gamma$-rays. In this work, we study radio, optical, and $\gamma$-ray light curves of 145 bright blazars spanning up to 8~yr, to probe the…

High Energy Astrophysical Phenomena · Physics 2018-08-20 I. Liodakis , R. W. Romani , A. V. Filippenko , S. Kiehlmann , W. Max-Moerbeck , A. C. S. Readhead , W. Zheng

We have made high precision polarimetric observations of the polluted white dwarf G29-38 with the HIgh Precision Polarimetric Instrument 2. The observations were made at two different observatories -- using the 8.1-m Gemini North Telescope…

Solar and Stellar Astrophysics · Physics 2020-04-29 Daniel V. Cotton , Jeremy Bailey , J. E. Pringle , William B. Sparks , Ted von Hippel , Jonathan P. Marshall

The polarization properties of extragalactic radio sources at frequencies higher than 20 GHz are still poorly constrained. However, their characterization would provide invaluable information about the physics of the emission processes and…

Astrophysics of Galaxies · Physics 2016-11-28 V. Galluzzi , M. Massardi

At optical/ultraviolet energies, blazars display an underlying thermal (unpolarized) contribution from the accretion disc, torus and line emitting regions, diluting the polarized emission from the jet-component. Optical polarimetry can be…

Through polarization observations water masers are excellent probes of magnetic fields in the maser region. Magnetic field strengths, such as those in the water masers regions of the envelopes of late-type stars and star-forming regions,…

Astrophysics · Physics 2009-11-11 W. H. T. Vlemmings

We present a study of the dynamics and magnetic activity of M dwarfs using the largest spectroscopic sample of low-mass stars ever assembled. The age at which strong surface magnetic activity (as traced by H-alpha) ceases in M dwarfs has…

\textit{Extreme Ultraviolet Explorer} Deep Survey observations of cool stars (spectral type F to M) have been used to investigate the distribution of coronal flare rates in energy and its relation to activity indicators and rotation…

Astrophysics · Physics 2015-06-24 Marc Audard , Manuel Guedel , Jeremy J. Drake , Vinay L. Kashyap

Gravitational microlensing, in case of relevant finite source size effects, provides an unique tool for the study of stellar atmospheres through the enhancement of a characteristic polarization signal. Here, we consider a set of highly…

Astrophysics of Galaxies · Physics 2013-04-23 A. A. Nucita , G. Ingrosso , F. De Paolis , F. Strafella , S. Calchi-Novati , Ph. Jetzer , A. F. Zakharov

We present the results from the first large (>100 source) 3.5 mm polarimetric survey of radio loud active galactic nuclei (AGN). The I, Q, U, and V Stokes parameter observations were performed with the XPOL polarimeter at the IRAM 30m…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 I. Agudo , C. Thum , H. Wiesemeyer , T. P. Krichbaum

Rapidly rotating late M dwarfs are observed in two different branches of magnetic activity, although they operate in the same stellar parameter range. Current empirical evidence indicates that M dwarfs with spectral types ranging from M3 /…

Solar and Stellar Astrophysics · Physics 2025-11-18 Giuseppina Nigro , Francesco Berrilli , Giuseppe Bono , Dario Del Moro , Luca Giovannelli , Valentina Penza , Raffaele Reda

We have used NSF's Karl G. Jansky Very Large Array (VLA) to observe a sample of five known radio-emitting late L and T dwarfs ranging in age from ~0.2 - 3.4Gyr. We observed each target for seven hours, extending to higher frequencies than…

Solar and Stellar Astrophysics · Physics 2018-08-09 Melodie Kao , Gregg Hallinan , J. Sebastian Pineda , David Stevenson , Adam Burgasser
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