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Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/7153
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dc.contributor.authorPatel, Jigisha V-
dc.contributor.authorDeshpande, A.A.-
dc.date.accessioned2019-02-12T18:10:01Z-
dc.date.available2019-02-12T18:10:01Z-
dc.date.issued2019-01-19-
dc.identifier.citationJournal of Astrophysics and Astronomy, 2019, Vol. 40, p3en_US
dc.identifier.issn0250-6335-
dc.identifier.issn0973-7758(Online)-
dc.identifier.urihttp://hdl.handle.net/2289/7153-
dc.descriptionOpen Accessen_US
dc.description.abstractLunar occultation, which occurs when the Moon crosses sight-lines to distant sources, has been studied extensively through apparent intensity pattern resulting from Fresnel diffraction, and has been successfully used to measure angular sizes of extragalactic sources. However, such observations to-date have been mainly over narrow bandwidth, or averaged over the observing band, and the associated intensity pattern in time has rarely been examined in detail as a function of frequency over a wide band. Here, we revisit the phenomenon of lunar occultation with a view to study the associated intensity pattern as a function of both time and frequency. Through analytical and simulation approach, we examine the variation of intensity across the dynamic spectra, and look for chromatic signatures which could appear as discrete dispersed signal tracks, when the diffraction pattern is adequately smoothed by a finite source size. We particularly explore circumstances in which such diffraction pattern might closely follow the interstellar dispersion law followed by pulsars and transients, such as the Fast Radio Bursts (FRBs), which remain a mystery even after a decade of their discovery. In this paper, we describe details of this investigation, relevant to radio frequencies at which FRBs have been detected, and discuss our findings, along with their implications. We also show how a band-averaged light curve suffers from temporal smearing, and consequent reduction in contrast of intensity variation, with increasing bandwidth. We suggest a way to recover the underlying diffraction signature, as well as the sensitivity improvement commensurate with usage of large bandwidths.en_US
dc.language.isoenen_US
dc.publisherIndian Academy of Sciences, Bangalore, India.en_US
dc.relation.urihttps://ui.adsabs.harvard.edu//#abs/2019JApA...40....3P/abstracten_US
dc.relation.urihttps://arxiv.org/abs/1811.12714en_US
dc.relation.urihttps://doi.org/10.1007/s12036-018-9568-8en_US
dc.rights2019, Indian Academy of Sciencesen_US
dc.subjectMoon—occultation—ISMen_US
dc.subjectgeneral—radio continuum: generalen_US
dc.titleThe dynamic spectral signatures from lunar occultation: A simulation studyen_US
dc.typeArticleen_US
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