De, Kishalay and Gupta, Yashwant and Sharma, Prateek (2016) DETECTION OF POLARIZED QUASI-PERIODIC MICROSTRUCTURE EMISSION IN MILLISECOND PULSARS. In: ASTROPHYSICAL JOURNAL LETTERS, 833 (1).
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Abstract
Microstructure emission, involving short timescale, often quasi-periodic, intensity fluctuations in subpulse emission, is well known in normal period pulsars. In this Letter, we present the first detections of quasi-periodic microstructure emission from millisecond pulsars (MSPs), from Giant Metrewave Radio Telescope observations of two MSPs at 325 and 610 MHz. Similar to the characteristics of microstructure observed in normal period pulsars, we find that these features are often highly polarized and exhibit quasi-periodic behavior on top of broader subpulse emission, with periods of the order of a few mu s. By measuring their widths and periodicities from single pulse intensity profiles and their autocorrelation functions, we extend the microstructure timescale-rotation period relationship by more than an order of magnitude down to rotation periods similar to 5 ms, and find it to be consistent with the relationship derived earlier for normal pulsars. The similarity of behavior is remarkable, given the significantly different physical properties of MSPs and normal period pulsars, and rules out several previous speculations about the possible different characteristics of microstructure in MSP radio emission. We discuss the possible reasons for the non-detection of these features in previous high time resolution MSP studies along with the physical implications of our results, both in terms of a geometric beam sweeping model and temporal modulation model for micropulse production.
| Item Type: | Journal Article |
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| Publication: | ASTROPHYSICAL JOURNAL LETTERS |
| Additional Information: | Copy right for this article belongs to the IOP PUBLISHING LTD, TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND |
| Department/Centre: | Division of Physical & Mathematical Sciences > Physics |
| Date Deposited: | 30 Jan 2017 04:21 |
| Last Modified: | 30 Jan 2017 04:21 |
| URI: | http://eprints.iisc.ac.in/id/eprint/55963 |
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