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Mean pulse profiles and polarization properties are presented for nine southern pulsars. The observations were made using the Parkes radio telescope at frequencies near 1330 MHz; three of the nine pulsars were also observed at 660 MHz. A…

Astrophysics · Physics 2009-11-10 R N Manchester , J L Han

Radiation belts are present in all large-scale Solar System planetary magnetospheres: Earth, Jupiter, Saturn, Uranus, and Neptune. These persistent equatorial zones of trapped high energy particles up to tens of MeV can produce bright radio…

Earth and Planetary Astrophysics · Physics 2024-03-15 Melodie M. Kao , Amy J. Mioduszewski , Jackie Villadsen , Evgenya L. Shkolnik

We present polarisation profiles for 48 southern pulsars observed with the new 10-cm receiver at the Parkes telescope. We have exploited the low system temperature and high bandwidth of the receiver to obtain profiles which have good signal…

Astrophysics · Physics 2009-11-10 A. Karastergiou , S. Johnston , R. N. Manchester

Extrasolar planet searches targeting very low-mass stars and brown dwarfs are hampered by intrinsic or instrumental limitations. Time series of astrometric measurements with precisions better than one milli-arcsecond can yield new evidence…

Solar and Stellar Astrophysics · Physics 2014-05-08 J. Sahlmann , P. F. Lazorenko , D. Segransan , E. L. Martin , M. Mayor , D. Queloz , S. Udry

We explore the radio emission from the M9 dwarf, TVLM513-46546, at multiple radio frequencies, determining the flux spectrum of persistent radio emission, as well as constraining the levels of circular polarization. Detections at both 3.6…

Astrophysics · Physics 2009-11-13 Rachel A. Osten , Suzanne L. Hawley , Timothy S. Bastian , I. Neill Reid

We present precise measurements of radial (RV) and projected rotational ($v\sin{i}$) velocities, effective temperatures, and surface gravities of a sample of 258 M6 to L2 dwarfs with multi-epoch, high-resolution ($\lambda/\Delta\lambda$ =…

Radio galaxies are linearly polarized -- an important property that allows us to infer the properties of the magnetic field of the source and its environment. However at low frequencies, Faraday rotation substantially depolarizes the…

Context. The origin, evolution, and ultimate fate of magnetic cataclysmic variables are poorly understood. It is largely the nature of the magnetic fields in these systems that leads to this poor understanding. Fundamental properties, such…

Astrophysics of Galaxies · Physics 2009-11-13 O. W. Butters , S. Katajainen , A. J. Norton , H. J. Lehto , V. Piirola

With the purpose to investigate the radio emission of new ultracool objects, we carried out a targeted search in the recently discovered system VHS J125601.92$-$125723.9 (hereafter VHS 1256$-$1257); this system is composed by an equal-mass…

Solar and Stellar Astrophysics · Physics 2018-02-21 J. C. Guirado , R. Azulay , B. Gauza , M. A. Pérez-Torres , R. Rebolo , J. B. Climent , M. R. Zapatero-Osorio

We have conducted aperture polarimetry of ~500 stars of the Orion Nebula Cluster (ONC) in M42 based on our wide-field (~8'\times 8') $JHKs$ band polarimetry. Most of the near-infrared (NIR) polarizations are dichroic, with position angles…

Long-period transients (LPTs) are a new and enigmatic class of objects that produce bright pulsations in the radio, with periods far exceeding those seen in rotationally powered pulsars. The proposed progenitors for LPTs are contested, with…

Route & Wolszczan (2016) recently detected five radio bursts from the T6 dwarf WISEP J112254.73+255021.5 and used the timing of these events to propose that this object rotates with an ultra-short period of ~17.3 minutes. We conducted…

Solar and Stellar Astrophysics · Physics 2017-01-18 P. K. G. Williams , J. E. Gizis , E. Berger

We present a volume-limited, spectroscopically-verified sample of M7$-$L5 ultracool dwarfs within 25\,pc. The sample contains 410 sources, of which $93\%$ have trigonometric distance measurements ($80\%$ from \textit{Gaia} DR2), and $81\%$…

We conducted a Very Large Array survey of eleven low luminosity active galactic nuclei for linear and circular polarization at 8.4 GHz. We detected circular polarization in one source (M81*) and linear polarization in 3 sources. Sensitivity…

Astrophysics · Physics 2009-11-07 Geoffrey C. Bower , Heino Falcke , Richard R. Mellon

Radio detections of ultracool dwarfs provide insight into their magnetic fields and the dynamos that maintain them, especially at the very bottom of the main sequence, where other activity indicators dramatically weaken. Until recently,…

Solar and Stellar Astrophysics · Physics 2013-04-08 Peter K. G. Williams , Edo Berger , B. Ashley Zauderer

We present a sequence of high resolution (R~20,000 or 15 km/s) infrared spectra of stars and brown dwarfs spanning spectral types M2.5 to T6. Observations of 16 objects were obtained using eight echelle orders to cover part of the J-band…

We present results from a circular polarimetric survey of candidate detached magnetic white dwarf - M dwarf binaries obtained using the Nordic Optical Telescope, La Palma. We obtained phase resolved spectropolarimetry and imaging…

Solar and Stellar Astrophysics · Physics 2022-05-24 Pasi Hakala , Steven G. Parsons , Thomas R. Marsh , Boris T. Gänsicke , Gavin Ramsay , Axel Schwope , J. J. Hermes

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

We present the results of flux density, spectral index, and polarization intra-night monitoring studies of a sample of eight optically bright blazars, carried out by employing several small to moderate aperture (0.4\,m to 1.5\,m diameter)…

With the improvements in radio interferometry sensitivity, the quest for coherent radio emission from exoplanets and ultra-cool dwarfs, which is indicative of their magnetic fields, has gained significant momentum in recent years. We…