Measuring the Size of the Vela Pulsar's Radio Emission Region

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

4 pages, 2 figures, to appear in Proc. IAUC177 "Pulsar Astronomy - 2000 and Beyond," eds. M. Kramer, N. Wex & R. Wielebinski.

Scientific paper

We describe measurements of the size of the Vela pulsar via scintillation, using both fits to the distribution of intensity and measurements of the modulation index. We briefly discuss systematic effects other than source size that can affect the distribution, including gain variations, self-noise, scintillation shot noise, and correlator saturation. Modulation index, a single number, can be biased by all of these, whereas the distribution of intensity is affected in different ways by different effects, providing means of distinguishing among them. Self-noise and gain variations are likely more important at long observing wavelengths, and correlator saturation and scintillation shot noise at short wavelengths. We find a size of about 500 km at decimeter wavelengths. Interestingly, this agrees with measurements of modulation index by Roberts & Ables at the same wavelength. Their results (and more recently that reported by Macquart et al.) suggest that size decreases with increasing wavelength. Although consistent with the observations, this conclusion is perhaps surprising from the standpoint of the traditional radius-to-frequency mapping. However, these measurements are of size rather than height; and of course systematic effects may play a role.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Measuring the Size of the Vela Pulsar's Radio Emission Region 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 Measuring the Size of the Vela Pulsar's Radio Emission Region, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Measuring the Size of the Vela Pulsar's Radio Emission Region will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-232591

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.