Long-Term Scintillation Studies of Pulsars: I. Observations and Basic Results

Details Long-Term Scintillation Studies of Pulsars: I. Observations and Basic Results Long-Term Scintillation Studies of Pulsars: I. Observations and Basic Results

1998-10-22

arxiv.org/abs/astro-ph/9810354v1

Astronomy and Astrophysics

Astrophysics

39 pages, 7 Figures (21 pages) [All in "gif" format], 6 Tables (7 pages), Accepted for publication in The Astrophysical Journa

Scientific paper

10.1086/313198

We report long-term scintillation observations of 18 pulsars in the DM range 3-35 pc cm^{-3} carried out during 1993-1995 using the Ooty Radio Telescope at 327 MHz. These observations were made with the aim of studying refractive effects in pulsar scintillation, and obtaining reliable estimates of diffractive and refractive scintillation properties. Dynamic scintillation spectra of pulsars were regularly monitored at 10-90 epochs spanning 100-1000 days. Significant changes are observed in the dynamic spectra over time scales as short as a few days. Large-amplitude fluctuations are observed in quantities such as decorrelation bandwidth, scintillation time scale, drift rate, and flux density. Several pulsars show organized features such as drifting bands in a highly pronounced manner. For some pulsars, gradual and systematic variations are seen in the drift rate of patterns which undergo several sign reversals during the observing time spans. Anomalous behaviour such as persistent drifts lasting over many months are seen for PSRs B0834+06 & B1919+21. Four pulsars were studied for 2-4 well separated observing sessions, each lasting over ~ 100 days. In some cases, significant variations are seen in the average scintillation properties and/or flux densities between successive observing sessions. From our data, we have been able to obtain more accurate and reliable estimates of scintillation properties and flux densities than those from the earlier observations, by averaging out the fluctuations due to refractive scintillation effects. These measurements are used to derive parameters such as the strength of scattering and scintillation speeds. The present measurements are compared with earlier measurements and the long-term stability of scintillation properties and flux densities is discussed.

Affiliated with

Also associated with

No associations

Rating

Long-Term Scintillation Studies of Pulsars: I. Observations and Basic Results does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Long-Term Scintillation Studies of Pulsars: I. Observations and Basic Results, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Long-Term Scintillation Studies of Pulsars: I. Observations and Basic Results will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-266724