Previous | Session 183 | Next | Author Index | Block Schedule
M. L. Putney (Oberlin), A. H. Minter (NRAO), D. R. Stinebring (Oberlin), S. M. Ransom (NRAO)
Scintillation arcs are parabolic patterns in the secondary spectra of coherent sources such as pulsars. They indicate scattering localized in a thin screen along the line of sight and yield information about the location of the screen and its spectrum of inhomogeneities. Most scintillation arc observations have been obtained at Arecibo on very bright pulsars where the dynamic range is high. We conducted a search for parabolic arcs in the scintillation structure of 18 pulsars with the NRAO Green Bank Telescope at 350 MHz and 820 MHz. The 400 MHz flux densities for these pulsars were all above 40 mJy and the dispersion measures were less than 50~pc~cm-3. We detected clear scintillation arcs in 13 of the 18 sources and several of the others are possible detections. We comment on this high detection rate and its implications for sheet-like structures in the warm ionized medium (WIM).
This work was supported by the National Science Foundation.
Previous | Session 183 | Next
Bulletin of the American Astronomical Society, 37 #4
© 2005. The American Astronomical Soceity.