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A tendency for the axes of double-lobed radio quasars to be aligned with the electric vectors of optical polarization in the active galactic nuclei is well-known. However, the origin of the polarization and reason behind its correlation…

Astrophysics · Physics 2009-10-31 Gary D. Schmidt , Paul S. Smith

The photometric errors of the external calibrator for the FIRAS instrument on the COBE are smaller than the measurement errors on the cosmic microwave background (CMBR) spectrum (typically 0.02 MJy/sr, 1 sigma), and smaller than 0.01% of…

Astrophysics · Physics 2009-10-31 J. C. Mather , D. J. Fixsen , R. A. Shafer , C. Mosier , D. T. Wilkinson

After proposing a new method of deriving the atmospheric time constant from the speed of focus variations (Kellerer & Tokovinin 2007), we now implement it with the new instrument, FADE. FADE uses a 36-cm Celestron telescope that is modified…

Astrophysics · Physics 2009-11-13 A. Tokovinin , A. Kellerer , V. Coude Du Foresto

The detection of the primordial B-mode polarization signal of the cosmic microwave background (CMB) would provide evidence for inflation. Yet as has become increasingly clear, the detection of a such a faint signal requires an instrument…

Instrumentation and Methods for Astrophysics · Physics 2015-11-24 Peter C. Nagler , Dale J. Fixsen , Alan Kogut , Gregory S. Tucker

We present the first section of a radio continuum and polarization survey at medium Galactic latitudes carried out with the Effelsberg 100-m telescope at 1.4 GHz. Four large fields have been observed, which all together cover an area of…

Astrophysics · Physics 2009-10-31 B. Uyaniker , E. Fuerst , W. Reich , P. Reich , R. Wielebinski

The concept of pyramid wavefront sensors (PWFS) has been around about a decade by now. However, there is still a great lack of characterizing measurements that allow the best operation of such a system under real life conditions at an…

Astrophysics · Physics 2009-11-13 D. Peter , M. Feldt , B. Dorner , T. Henning , S. Hippler , J. Aceituno

We evaluate the effect of half-wave plate (HWP) imperfections inducing intensity leakage to the measurement of Cosmic Microwave Background (CMB) $B$-mode polarization signal with future satellite missions focusing on the tensor-to-scalar…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-03 Guillaume Patanchon , Hiroaki Imada , Hirokazu Ishino , Tomotake Matsumura

The bipolar reflection nebula OH 231.8+4.2 (OH 0739-14), centred on the Mira variable star QX Pup, has been mapped at Ks in linear polarization using the ESO SOFI near-infrared multi-mode instrument. The large scale linear polarization…

Astrophysics · Physics 2007-05-23 N. Ageorges , J. R. Walsh

Using the Submillimeter Array, we have made the first high angular resolution measurements of the linear polarization of Sagittarius A* at submillimeter wavelengths, and the first detection of intra-day variability in its linear…

Astrophysics · Physics 2009-11-13 D. P. Marrone , J. M. Moran , J. -H. Zhao , R. Rao

Infrared observations of the Galactic center (GC) provide a unique opportunity to study stellar and bow-shock polarization effects in a dusty environment. The goals of this work are to present new Ks- and Lp-band polarimetry on an…

Astrophysics of Galaxies · Physics 2015-06-16 Rainer M. Buchholz , Gunther Witzel , Rainer Schoedel , Andreas Eckart

Stellar spectropolarimetry is a relatively new remote sensing tool for exploring stellar atmospheres and circumstellar environments. We present the results of our HiVIS survey and a multi-wavelength ESPaDOnS follow-up campaign showing…

Instrumentation and Methods for Astrophysics · Physics 2015-03-17 D. M. Harrington , J. R. Kuhn

Optical properties of single-crystal monoclinic CuO in the range 70 - 6000 \cm were studied at temperatures from 7 to 300 K. Normal reflection spectra were obtained from the (001) and (010) crystal faces thus giving for the first time…

Strongly Correlated Electrons · Physics 2009-10-31 A. B. Kuz'menko , D. van der Marel , P. J. M. van Bentum , E. A. Tishchenko , C. Presura , A. A. Bush

The variation mechanism of blazars is a long standing open question. The polarization observation can provide us with more information to constrain models. In this work, we collect the long term multi-wavelength data of AO 0235+164, and…

High Energy Astrophysical Phenomena · Physics 2020-10-21 Yifan Wang , Yunguo Jiang

A fully analytic statistical formalism does not yet exist to describe radio-wavelength measurements of linearly polarized intensity that are produced using rotation measure synthesis. In this work we extend the analytic formalism for…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Christopher A. Hales , Bryan M. Gaensler , Ray P. Norris , Enno Middelberg

LOFAR, the Low-Frequency Array, is a powerful new radio telescope operating between 10 and 240 MHz. LOFAR allows detailed sensitive high-resolution studies of the low-frequency radio sky. At the same time LOFAR also provides excellent short…

We present results of multifrequency polarimetric VLBA observations of 34 compact radio sources. The observations are part of a large survey undertaken to identify CSOs Observed in the Northern Sky (COINS). Based on VLBI continuum surveys…

Astrophysics · Physics 2007-05-23 A. B. Peck , G. B. Taylor

We report the measurement of X-ray polarization in the high synchrotron peaked blazar 1ES 1959+650. Of the four epochsof observations from the {\it Imaging X-ray Polarimetry Explorer}, we detected polarization in the 2$-$8 keV band on two…

High Energy Astrophysical Phenomena · Physics 2024-09-06 Athira M. Bharathan , C. S. Stalin , Rwitika Chatterjee , S. Sahayanathan , Indrani Pal , Blesson Mathew , Vivek K. Agrawal

We have developed a bolometric detector that is intrinsically sensitive to linear polarization which is optimized for making measurements of the polarization of the cosmic microwave background radiation. The receiver consists of a pair of…

Astrophysics · Physics 2020-12-22 W. C. Jones , R. S. Bhatia , J. J. Bock , A. E. Lange

Contamination due to foregrounds (Galactic and Extra-galactic), calibration errors and ionospheric effects pose major challenges in detection of the cosmic 21 cm signal in various Epoch of Reionization (EoR) experiments. We present the…

Instrumentation and Methods for Astrophysics · Physics 2018-05-15 B. K. Gehlot , L. V. E. Koopmans , A. G. de Bruyn , S. Zaroubi , M. A. Brentjens , K. M. B. Asad , M. Hatef , V. Jelic , M. Mevius , A. R. Offringa , V. N. Pandey , S. Yatawatta