Pulsar Observations and Structure of the Local ISM

• Published in: Astrophysics and space science Vol. 276; no. 1; p. 227
• Main Authors: Ramesh Bhat, Nd, Gupta, Yashwant, Pramesh Rao, A
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Nature B.V 01.01.2001
• Subjects: Astrophysics; Plasma; Pulsars
• ISSN: 0004-640X; 1572-946X
• DOI: 10.1023/A:1011686012602

Results from new observations of pulsars using the Ooty Radio Telescope(ORT) are used for investigating the structure of the Local InterstellarMedium (LISM) and the nature of the plasma turbulence spectrum in theInterstellar Medium (ISM). The observations show anomalous scintillationtowards several nearby pulsars, and these are modelled in terms oflarge-scale spatial inhomogeneities in the distribution of plasma densityfluctuations in the LISM. A 3-component model, where the Solar neighborhoodis surrounded by a shell of enhanced plasma turbulence, is proposed for theLISM. The inferred scattering structure is strikingly similar to the LocalBubble. The nature of the plasma turbulence spectrum is found to be Kolmogorov-like in the spatial scale range 10^sup 6^ m to 10^sup 11^ m,and there is evidence for excess power at larger spatial scales.[PUBLICATION ABSTRACT]