Modeling Pulsar Gamma-Ray Light Curves Using Realistic Magnetospheric Geometries
Gamma-ray emission from pulsars is thought to arise from accelerating re gions in pulsar magnetospheres that are located near the boundary between the open and closed field lines. The shape of the light curve is thus sensitive to the details of the magnetic geometry of the magnetosphere. In this work, we show the first calcula tions of light curves from the more realistic field from force-free simulations within the framework of two-pole caustic model. We compare the properties of gamma-ray emis sion between the commonly used vacuum dipole magnetic field and the new force-free field. We discuss the role of the polar cap shape and aberration effects on the appear ance of the light curve and the formation of caustics of emission. With the force-free field, the double-peak pulse profile is best reproduced if the emission zone is in a thin layer outside the current sheet, and caustics are formed around the light cylinder. The traditional outer-gap model can only produce one single peak using the force--free field. These results will be useful for interpreting Fermi telescope observations.
gamma rays theory pulsars general stars magnetic fields
X.-N. Bai A. Spitkovsky
Department of Astrophysical Sciences,Princeton University, Princeton, NJ, 08544, USA Department of Astrophysical Sciences, Princeton University, Princeton, NJ, 08544, USA
国际会议
The 10th Asian-Pacific Regional International Astronomical Union Meeting(第十届亚洲及太平洋地区天文学大会 APRIM)
昆明
英文
200-203
2008-08-03（万方平台首次上网日期，不代表论文的发表时间）