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We present CO(2-1), $^{13}$CO(2-1), CO(6-5), CO(7-6), and SO(6$_5-5_4$) line observations made with the {\it IRAM 30 m} and {\it APEX} radiotelescopes and the {\it Submillimeter Array} toward the highly collimated and extended southwest…

Astrophysics of Galaxies · Physics 2015-05-13 Luis A. Zapata , Johannes Schmid-Burgk , Dirk Muders , Peter Schilke , Karl Menten , Rolf Guesten

We report on full-polarization radio observations of the Perseus cluster (Abell 426) using the Westerbork Synthesis Radio Telescope (WSRT) at wavelengths from 81-95 cm. We have employed a novel technique, Rotation Measure synthesis…

Astrophysics · Physics 2009-11-13 A. G. de Bruyn , M. A. Brentjens

Six asteroids including two NEAs, one of which is PHA, accessible for observation in September 2012 were investigated using a low-resolution spectrophotometry in the range 0.35-0.90 um with the aim to study features of their reflectance…

Earth and Planetary Astrophysics · Physics 2015-09-23 Vladimir V. Busarev , Sergey I. Barabanov , Vyacheslav S. Rusakov , Vasiliy B. Puzin , Valery V. Kravtsov

The relationship between submillimeter (submm) dust emission polarization and near-infrared (NIR) $H$-band polarization produced by dust dichroic extinction was studied for the cold starless dense core FeSt 1-457. The distribution of…

Space coronagraph Metis on board of the Solar Orbiter offers us new capabilities for studying eruptive prominences and coronal mass ejections (CME). Its two spectral channels, hydrogen L$\alpha$ and visible-light (VL) will provide, for the…

Solar and Stellar Astrophysics · Physics 2020-09-02 Petr Heinzel , Jiří Štěpán , Alessandro Bemporad , Silvano Fineschi , Sonja Jejčič , Nicolas Labrosse , Roberto Susino

We reduced ESO's archival linear spectropolarimetry data (4000-9000\AA) of 6 highly polarized and 8 unpolarized standard stars observed between 2010 and 2016, for a total of 70 epochs, with the FOcal Reducer and low dispersion Spectrograph…

Instrumentation and Methods for Astrophysics · Physics 2016-10-12 Aleksandar Cikota , Ferdinando Patat , Stefan Cikota , Tamar Faran

The observed polarization of radio pulsars involves several peculiar effects, such as comparable amount of orthogonal polarization modes (OPMs) which often bear the same handedness of circular polarisation V. In the average profiles of…

High Energy Astrophysical Phenomena · Physics 2018-08-22 J. Dyks

We report observations of the linear polarization of a sample of 49 nearby bright stars measured to sensitivities of between ~1 and 4 x 10^-6. The majority of stars in the sample show measurable polarization, but most polarizations are…

Solar and Stellar Astrophysics · Physics 2015-05-18 Jeremy Bailey , P. W. Lucas , J. H. Hough

Observations of the optical polarization of NGC 4151 in 1997-2003 show variations of an order of magnitude in the polarized flux while the polarization position angle remains constant. The amplitude of variability of the polarized flux is…

We report detailed analyses of deep, high-resolution spectra of three Galactic planetary nebulae (PNe) with high abundance discrepancy factors (ADFs), Hf2-2, M1-42 and NGC6153, obtained with the Ultraviolet and Visual Echelle Spectrograph…

Solar and Stellar Astrophysics · Physics 2025-12-05 Haomiao Huang , Xuan Fang , Jorge Garcia-Rojas , Zhijun Tu , Jifeng Liu , Xiaowei Liu

We use ground-based imaging polarimetry to detect and image the dusty circumstellar envelopes of a sample of proto-planetary nebulae (PPNe) at near-infrared wavelengths. We detect extended (up to 9 arcsec diameter) circumstellar envelopes…

Astrophysics · Physics 2009-10-31 T. M. Gledhill , A. Chrysostomou , J. H. Hough , J. A. Yates

Aims. We aim at studying the near infrared linear polarization signal of rapidly rotating ultracool dwarfs with spectral types ranging from M7 through T2 and projected rotational velocities vsini >= 30 km s^{-1}. All these dwarfs are…

Solar and Stellar Astrophysics · Physics 2015-06-16 Paulo Alberto Miles-Páez , María Rosa Zapatero Osorio , Enric Pallé , Karla Peña Ramírez

We interpret the linear polarization structures observed in extragalactic radio sources, even those oriented at oblique angles to the jet flows, to be due to oblique, relativistic shock fronts in the emitting regions. Many sources exhibit…

Astrophysics · Physics 2007-05-23 H. D. Aller , M. F. Aller , P. A. Hughes

This paper presents optical UBVRI broadband photo-polarimetry of the EXPORT sample obtained at the 2.5m Nordic Optical Telescope. The database consists of multi-epoch photo-polarimetry of 68 pre-main-sequence and main-sequence stars. An…

Astrophysics · Physics 2009-11-07 R. D. Oudmaijer , J. Palacios , C. Eiroa , the EXPORT collaboration

LINER nuclei, which are present in many nearby galactic bulges, may be the manifestation of low-rate or low-radiative-efficiency accretion onto supermassive central black holes. However, it has been unclear whether the compact UV nuclear…

Astrophysics · Physics 2009-11-10 Dan Maoz , Neil M. Nagar , Heino Falcke , Andrew S. Wilson

We analyse dispersion measure (DM) variations in six years of radio observations of more than 160 young pulsars, all gamma ray candidates for the Fermi gamma ray telescope mostly located close to the Galactic plane. DMs were fit across 256…

Astrophysics of Galaxies · Physics 2015-06-16 E. Petroff , M. J. Keith , S. Johnston , W. van Straten , R. M. Shannon

Space missions to NEOs are being planned at all major space agencies, and recently a manned mission to an NEO was announced as a NASA goal. Efforts to find and select suitable targets (plus backup targets) are severely hampered by our lack…

In this work we present a revised measurement of the phase-averaged optical polarisation of the Vela pulsar (PSR B0833-45), for which only one value has been published so far (Wagner & Seifert 2000). Our measurement has been obtained…

Astrophysics · Physics 2009-11-13 R. P. Mignani , S. Bagnulo , J. Dyks , G. Lo Curto , A. Slowikowska

The fact that the O-type close binary star system AO~Cassiopeiae exhibits variable phase-locked linear polarization has been known since the mid-1970s. In this work, we re-observe the polarization arising from this system more than 50 years…

Solar and Stellar Astrophysics · Physics 2023-03-01 Yasir Abdul Qadir , Andrei V. Berdyugin , Vilppu Piirola , Takeshi Sakanoi , Masato Kagitani

We measured the linear polarization of Sagittarius A* to be 7.2 +/- 0.6 % at 230 GHzusing the BIMA array with a resolution of 3.6 x 0.9 arcsec. This confirms the previously reported detection with the JCMT 14-m antenna. Our high resolution…

Astrophysics · Physics 2008-11-26 Geoffrey C. Bower , Melvyn C. H. Wright , Heino Falcke , Donald C. Backer
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