Modeling High-energy Light curves of the PSR B1259-63/LS 2883 Binary Based on 3D SPH Simulations
Abstract
Temporal changes of X-ray to very high energy gamma-ray emissions from the pulsar-Be-star binary PSR B1259-63/LS 2883 are studied based on three-dimensional smoothed particle hydrodynamic simulations of pulsar wind interaction with Be-disk and wind. We focus on the periastron passage of the binary and calculate the variation of the synchrotron and inverse-Compton emissions using the simulated shock geometry and pressure distribution of the pulsar wind. The characteristic double-peaked X-ray light curve from observations is reproduced by our simulation under a dense Be-disk condition (base density ~10-9 g cm-3). We interpret the pre- and post-periastron peaks as being due to a significant increase in the conversion efficiency from pulsar spin-down power to the shock-accelerated particle energy at orbital phases when the pulsar crosses the disk before periastron passage, and when the pulsar wind creates a cavity in the disk gas after periastron passage, respectively. On the contrary, in the model TeV light curve, which also shows a double-peak feature, the first peak appears around the periastron phase. The possible effects of cooling processes on the TeV light curve are briefly discussed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 2012
- DOI:
- 10.1088/0004-637X/750/1/70
- arXiv:
- arXiv:1203.2179
- Bibcode:
- 2012ApJ...750...70T
- Keywords:
-
- hydrodynamics;
- pulsars: individual: PSR B1259–63;
- radiation mechanisms: non-thermal;
- stars: individual: LS 2883;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 32 pages, 6 figues. Accepted for publication in ApJ