Abstract Details
| Name: Atul Mohan Affiliation: NCRA-TIFR Conference ID: ASI2018_450 Title : Exploring coronal faint non-thermal emission features using high Dynamic range snapshot-spectroscopic metrewave-imaging Authors and Co-Authors : Divya Oberoi, NCRA-TIFR, Pune Abstract Type : Poster Abstract Category : Sun and the Solar System Abstract : Metrewave solar observations are important to study the solar coronal plasma dynamics. This is because this emission originates from larger coronal heights (~ 1.1 - 2 Rsun), where the EUV and X-ray emission becomes increasingly faint or undetectable; and these frequencies are very sensitive to non-thermal emissions which relate to a wide range of interesting solar physics. Metrewave emissions span a very large range in intensity, as well as temporal, spectral and spatial scales. Often multiple processes go on simultaneously at different locations on the Sun, giving rise to emission features with very different strengths. Till recently, one could usually only study the most intense of these, limited by the information gathering capacity of traditional arrays. The new generation of low-frequency interferometric arrays, like the Murchison Widefield Array (MWA), offer high dynamic range snapshot-spectroscopic-imaging capability. This unprecedented capability enables us to track the evolution of coronal brightness as a funtion of time and frequency across the solar disc. To facillitate the studies of emission features which do not dominate the disc-integrated solar flux density, and hence cannot be studied using the conventional dynamic spectrum (DS) based techniques, we introduce a new data product. In analogy with the usual DS, we name it SPatially REsolved Dynamic Spectrum or SPREDS. We use SPREDS derived from the MWA data to demonstrate that radio observations are sensitive to a class of weak features which do not seem to be detected in EUV and X-ray observations. |