English
Related papers

Related papers: Linear polarization of rapidly rotating ultracool …

200 papers

We have observed 6 late-L and T dwarfs with the Karl G. Jansky Very Large Array (VLA) to investigate the presence of highly circularly polarized radio emission, associated with large-scale auroral currents. Previous surveys encompassing ~60…

Solar and Stellar Astrophysics · Physics 2016-02-17 Melodie M. Kao , Gregg Hallinan , J. Sebastian Pineda , Ivanna Escala , Adam Burgasser , Stephen Bourke , David Stevenson

Theoretical analysis and observational evidences indicate that a brown dwarf with effective temperature greater than 1400 K would have dust cloud in its atmosphere. In this letter, we show that dust scattering should yield polarized…

Astrophysics · Physics 2009-11-07 Sujan Sengupta , Vinod Krishan

We investigate the structure of the O-type binary system HD 48099 by measuring linear polarization that arises due to light scattering process. Linear polarization measurements of HD 48099 in the B, V and R passbands with the high-precision…

Solar and Stellar Astrophysics · Physics 2016-06-02 A. Berdyugin , V. Piirola , S. Sadegi , S. Tsygankov , T. Sakanoi , M. Kagitani , M. Yoneda , S. Okano , J. Poutanen

We present milliarcsecond-resolution radio very long baseline interferometry (VLBI) observations of the ultracool dwarfs TVLM513-46546 (M8.5) and 2MASS J00361617+1821104 (L3.5) in an attempt to detect sub-stellar companions via direct…

Solar and Stellar Astrophysics · Physics 2014-11-20 J. Forbrich , E. Berger

We present high signal-to-noise, full polarization pulse profiles for 40 bright, 'slowly'-rotating (non-recycled) pulsars using the new Ultra-Wideband Low-frequency (UWL; 704-4032 MHz) receiver on the Parkes radio telescope. We obtain…

High Energy Astrophysical Phenomena · Physics 2021-03-26 C. Sobey , S. Johnston , S. Dai , M. Kerr , R. N. Manchester , L. S. Oswald , A. Parthasarathy , R. M. Shannon , P. Weltevrede

Recent observations with the LOw Frequency ARray (LOFAR) have revealed 19 nearby M dwarfs showing bright circularly polarised radio emission. One of the possible sources of such emission is through magnetic star-planet interactions (MSPI)…

Scallop-shell stars, a recently discovered class of young M dwarfs, show complex optical light curves that are characterized by periodic dips as well as other features that are stable over tens to hundreds of rotation cycles. The origin of…

Well-characterized binary systems will provide valuable opportunities to study the conditions that are necessary for the onset of both auroral and non-auroral magnetospheric radio emission in the ultracool dwarf regime. We present new…

Solar and Stellar Astrophysics · Physics 2022-06-22 Melodie M. Kao , J. Sebastian Pineda

In a volume-limited sample of 63 ultracool dwarfs of spectral type M7-M9.5, we have obtained high-resolution spectroscopy with UVES at the Very Large Telescope and HIRES at Keck Observatory. In this second paper, we present projected…

Solar and Stellar Astrophysics · Physics 2014-11-20 Ansgar Reiners , Gibor Basri

Ultracool dwarfs, the least-massive contributors to the stellar mass function, exhibit striking magnetic properties that are inconsistent with trends for more massive stars. Here, we present the widest-band radio observations to date of an…

Solar and Stellar Astrophysics · Physics 2015-05-28 V. Ravi , G. Hallinan , G. Hobbs , D. J. Champion

We report detection of strong circularly polarized emission from the transient bursting source GCRT J1745-3009 based on new analysis of 325 MHz GMRT observations conducted on 28 September 2003. We place 8 Solar radius as the upper limit on…

Astrophysics of Galaxies · Physics 2015-05-18 Subhashis Roy , Scott D. Hyman , Sabyasachi Pal , T. Joseph W. Lazio , Paul S. Ray , Namir E. Kassim

We present the results of spectroscopic follow-up observations for a sample of 71 red objects with high proper motions in the range 0.08-1.14 arcsec/yr as detected using APM and SSS measurements of multi-epoch photographic Schmidt plates.…

Astrophysics · Physics 2009-11-11 N. Lodieu , R. -D. Scholz , M. J. McCaughrean , R. Ibata , M. Irwin , H. Zinnecker

From 1994 to 1997 we monitored the optical spectrum of RXJ0019.8+2156. This supersoft X-ray source is one of only two accreting white dwarfs in the Galaxy thought to be burning hydrogen on their surface as a consequence of a high rate of…

Astrophysics · Physics 2009-10-30 C. M. Becker , R. A. Remillard , S. A. Rappaport , J. E. McClintock

How pulsars radiate is a long-standing problem. Detailed polarization measurements of individual pulses shed light on currently unknown emission processes. Recently, based on supersensitive observations, dwarf pulses have been recognized as…

High Energy Astrophysical Phenomena · Physics 2024-03-19 Yi Yan , J. L. Han , D. J. Zhou , L. Xie , F. F. Kou , P. F. Wang , C. Wang , T. Wang

We analyse the circular polarisation data accumulated in the first 7 years of the POLAMI project introduced in an accompanying paper (Agudo et al.). In the 3mm wavelength band, we acquired more than 2600 observations, and all but one of our…

We present an overview of new HST imaging polarimetry of six nearby radio galaxies with optical jets. These observations triple the number of extragalactic jets with subarcsecond-resolution optical polarimetry. We discuss the polarization…

A search of the Two Micron All Sky Survey and Sloan Digital Sky Survey reveals 36 previously unknown high proper motion objects with J<17. Their red-optical colors indicate that 27 are M dwarfs, 8 are early-type L dwarfs, and 1 is a…

Astrophysics · Physics 2009-11-13 Scott S. Sheppard , Michael C. Cushing

It has been argued that certain broad absorption line quasars are viewed within 35 degrees of the axis of a relativistic radio jet, based on two-epoch radio flux density variability. It is true if the surface brightness of a radio source is…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-17 Patrick B. Hall , Laura S. Chajet

Linearly polarized emission is described, in general, in terms of the Stokes parameters $Q$ and $U$, from which the polarization intensity and polarization angle can be determined. Although the polarization intensity and polarization angle…

Astrophysics of Galaxies · Physics 2018-01-31 C. A. Herron , B. M. Gaensler , G. F. Lewis , N. M. McClure-Griffiths

We report on UBVRI polarimetry of the recently identified Intermediate Polar 1WGA J1958.2+3232, carried out on 2000 August, 4-6 at the Nordic Optical Telescope. Circular polarization was detected in R and I bands with an increasing absolute…

Astrophysics · Physics 2009-11-06 M. Uslenghi , L. Tommasi , A. Treves , V. Piirola , P. Reig