Previous | Session 111 | Next
S. Redman (University of Vermont), G. Wright (University of Sussex, UK), J. Rankin (University of Vermont)
Analyses of multiple pulse sequences of pulsar B2303+30 reveal two distinct emission modes. One mode (B) follows a steady even-odd pattern and is more intense. The second mode (Q) is characteristically about half as intense, and often exhibits driftbands with a periodicity of approximately 3P1/cycles. It also nulls much more frequently than the B mode, possibly exclusively. Changes in driftrate are well known to accompany mode changes, but this is the first instance of a strongly mode-dependent nulling behavior. Both modes occur with roughly equal frequency, and their profiles have a similar single-humped form with a slight asymmetry. Our observations and analyses strongly suggest that the subpulse driftrates in both modes are linked in a series of cycles, which can be modeled as relaxing oscillations in the underlying circulation rate. In this context, the nulls seem to occur when the driftrate is changing most rapidly.
One of us (SLR) wishes to acknowledge a HELiX/EPSCoR Summer Research Fellowship. Portions of this work were carried out with support from US National Science Foundation Grant AST 99-87654. Arecibo Observatory is operated by Cornell University under contract to the US NSF.
The author(s) of this abstract have provided an email address for comments about the abstract: Stephen.Redman@uvm.edu
Previous | Session 111 | Next
Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.