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Proposal Identification No.: P2532 Date Received: 2009­Oct­02 10:17:38
Technical Page
Proposal Type: Regular
General Category: Pulsars
Observation Category: Galactic
Total Time Requested: 40 Hours
Minimum Useful Time: 3­4 hours
Proposal Title: A survey of high time resolution single pulse absolute polarimetry of pulsars:
Probing the coherent radio emission problem
ABSTRACT:
Recently Mitra et al. (2009) have shown that occasionally single pulses are highly linearly polarized, having a sign
changing circular and its polarization position angle following locally the mean position angle traverse. They
argue that this is a typical signature of curvature radiation in vacuum. However, theoretically only the
extraordinary mode can escape from the pulsar magnetosphere preserving its vacuum like properties. This is in
contradiction with observations of circular polarization and OPM in pulsar radiation, where both extraordinary
and ordinary mode need to be present. Further sensitive single pulse polarimetry is essential to understand the
origin of circular and OPM in pulsars. Mitra et. al.'s single pulses were associated only with the primary
(stronger) polarization mode, and hence an important question is if such single pulses are present in the secondary
(weaker) polarization modes. Also a key to understand the pulsar emission process lie in how the smaller units of
emission average to form these highly polarized single pulses. With an aim to answer these questions we propose
to do a systematic survey of high time resolution single pulse polarization of bright pulsars. The Arecibo telescope
is uniquely suited for this purpose due to it high sensitivity and available backends that can yield high time
resolution data. We request 40 hours of observations, with 20 hours each at P and L band, to observer
20 strong pulsars.
Name Institution E­mail Phone Student
Dipanjan Mitra National Centre for
Radio Astrophysics,
TIFR
dmitra@ncra.tifr.res.in +91 20
25719247
no
Remote Observing Request
X Observer will travel to AO
Remote Observing
In Absentia (instructions to oper­
ator)
Instrument Setup
1

L­wide 327
Atmospheric Observation Instruments:
Special Equipment or setup: none
RFI Considerations
Frequency Ranges Planned
This proposal requires Iridium RFI protection at 1612 MHz between 10pm and 6am EST.
This proposal requires coordination with Punta Salinas radar within the band 1222­1381 MHz..
This proposal requires coordination with GPS L3 at 1381 MHz.
2