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At the site of their origin, solar meterwave radio bursts contain pristine information about the local coronal magnetic field and plasma parameters. On its way through the turbulent corona, this radiation gets substantially modified due to…

Solar and Stellar Astrophysics · Physics 2019-05-01 Atul Mohan , Surajit Mondal , Divya Oberoi , Colin Lonsdale

Solar radio observations provide a unique diagnostic of the outer solar atmosphere. However, the inhomogeneous turbulent corona strongly affects the propagation of the emitted radio waves, so decoupling the intrinsic properties of the…

Solar and Stellar Astrophysics · Physics 2018-02-22 E. P. Kontar , S. Yu , A. A. Kuznetsov , A. G. Emslie , B. Alcock , N. L. S. Jeffrey , V. N. Melnik , N. H. Bian , P. Subramanian

The new generations of multiwavelength radioheliographs with high spatial resolution will employ microwave imaging spectropolarimetry to recover flare topology and plasma parameters in the flare sources and along the wave propagation paths.…

Solar and Stellar Astrophysics · Physics 2017-09-27 A. Altyntsev , N. Meshalkina , I. Myshyakov , V. Pal`shin , G. Fleishman

We present a census of 100 pulsars, the largest below 100 MHz, including 94 normal pulsars and six millisecond pulsars, with the Long Wavelength Array (LWA). Pulse profiles are detected across a range of frequencies from 26 to 88 MHz,…

High Energy Astrophysical Phenomena · Physics 2025-03-31 Pratik Kumar , Greg B. Taylor , Kevin Stovall , Jayce Dowell , Stephen M. White

Observational detection of quasi-periodic drifting fine structures in a type III radio burst associated with a solar flare SOL2015-04-16T11:22, with Low Frequency Array, is presented. Although similar modulations of the type III emission…

Solar and Stellar Astrophysics · Physics 2018-07-11 Dmitrii Y. Kolotkov , Valery M. Nakariakov , Eduard P. Kontar

The Sun has remained a difficult source to image for radio telescopes, especially at the low radio frequencies. Its morphologically complex emission features span a large range of angular scales, emission mechanisms involved and brightness…

We analyse a 154 MHz image made from a 12 h observation with the Murchison Widefield Array (MWA) to determine the noise contribution and behaviour of the source counts down to 30 mJy. The MWA image has a bandwidth of 30.72 MHz, a…

The elemental composition of the Sun's hot atmosphere, the corona, shows a distinctive pattern that is different than the underlying surface, or photosphere (Pottasch 1963). Elements that are easy to ionize in the chromosphere are enhanced…

Solar and Stellar Astrophysics · Physics 2022-05-18 David H. Brooks , Deborah Baker , Lidia van Driel-Gesztelyi , Harry P. Warren , Stephanie L. Yardley

The recent availability of fine grained high sensitivity data from the new generation low radio frequency instruments such as the Murchison Widefield Array (MWA) have opened up opportunities for using novel techniques for characterizing the…

Solar and Stellar Astrophysics · Physics 2018-01-24 Rohit Sharma , Divya Oberoi , Mihir Arjunwadkar

Waves are thought to play a significant role in the heating of the solar atmosphere and the acceleration of the wind. Among the many types of waves observed in the Sun, the so-called p-modes with a 3 mHz frequency peak dominate the lower…

We present a novel experiment with the capacity to independently measure both the electron density and the magnetic field of the solar corona. We achieve this through measurement of the excess Faraday rotation due to propagation of the…

Astrophysics · Physics 2009-11-13 S. M. Ord , S. Johnston , J. Sarkissian

Faraday rotation measurements of the solar corona made with the Very Large Array (VLA) at frequencies of 1465 and 1665 MHz are reported. The measurements were made along 20 lines of sight to 19 extragalactic radio sources in March and…

Astrophysics · Physics 2008-11-26 Laura D. Ingleby , Steven R. Spangler , Catherine A. Whiting

The Murchison Widefield Array (MWA), and its recently-developed Voltage Capture System (VCS), facilitates extending the low-frequency range of pulsar observations at high-time and -frequency resolution in the Southern Hemisphere, providing…

High Energy Astrophysical Phenomena · Physics 2018-01-23 Mengyao Xue , N. D. R. Bhat , S. E. Tremblay , S. M. Ord , C. Sobey , N. A. Swainston , D. L. Kaplan , Simon Johnston , B. W. Meyers , S. J. McSweeney

The total solar eclipse of August 21st, 2017 was observed with a Digital Single Lens Reflex (DSLR) camera equipped with a linear polarizing filter. A method was developed to combine images acquired with 15 different exposure times (from…

Solar and Stellar Astrophysics · Physics 2020-12-09 Alessandro Bemporad

Low frequency imaging radio arrays such as MWA, LWA and LOFAR have been recently commissioned, and significantly more advanced and flexible arrays are planned for the near term. These powerful instruments offer new opportunities for direct…

Instrumentation and Methods for Astrophysics · Physics 2018-02-07 C. Lonsdale , L. Benkevitch , I. Cairns , M. Crowley , P. Erickson , M. Knapp , K. Kozarev , F. Lind , P. McCauley , J. Morgan , D. Oberoi

Metric and decametric radio-emissions from the Sun are the only direct source of information about the dynamics of non-thermal electrons in the upper corona. In addition, the combination of spectral and imaging (sizes, shapes, and…

Solar and Stellar Astrophysics · Physics 2022-02-09 M. Gordovskyy , E. P. Kontar , D. L. Clarkson , N. Chrysaphi , P. K. Browning

EUV images of Comet Lovejoy (C/2011 W3) from the AIA show striations related to the magnetic field structure in both open and closed magnetic regions. The brightness contrast implies coronal density contrasts of at least a factor of 6…

Solar and Stellar Astrophysics · Physics 2015-06-19 J. C. Raymond , P. I. McCauley , S. R. Cranmer , C. Downs