科技报告详细信息
Multi-Zone Modeling of the Pulsar Win Nebula HESS J1825-137 | |
Van Etten, Adam ; Romani, Roger W. ; /Stanford U., Phys. Dept. | |
SLAC National Accelerator Laboratory | |
关键词: Diffusion; Energy Sources; Brightness; Energy Spectra; 70 Plasma Physics And Fusion Technology; | |
DOI : 10.2172/1029129 RP-ID : SLAC-PUB-14547 RP-ID : AC02-76SF00515 RP-ID : 1029129 |
|
美国|英语 | |
来源: UNT Digital Library | |
【 摘 要 】
The pulsar wind nebula associated with PSR J1826-1334, HESS J1825-137, is a bright very high energy source with an angular extent of {approx} 1{sup o} and spatially-resolved spectroscopic TeV measurements. The gamma-ray spectral index is observed to soften with increasing distance from the pulsar, likely the result of cooling losses as electrons traverse the nebula. We describe analysis of X-ray data of the extended nebula, as well as 3-D time-dependent spectral energy distribution modeling, with emphasis on the spatial variations within HESS J1825-137. The multi-wavelength data places significant constraints on electron injection, transport, and cooling within the nebula. The large size and high nebular energy budget imply a relatively rapid initial pulsar spin period of 13 {+-} 7 ms and an age of 40 {+-} 9 kyr. The relative fluxes of each VHE zone can be explained by advective particle transport with a radially decreasing velocity profile with v(r) {proportional_to} r{sup -0.5}. The evolution of the cooling break requires an evolving magnetic field which also decreases radially from the pulsar, B(r, t) {proportional_to} r{sup -0.7} E(t){sup 1/2}. Detection of 10 TeV flux {approx} 80 pc from the pulsar requires rapid diffusion of high energy particles with {tau}{sub esc} {approx} 90 (R/10 pc){sup 2}(E{sub e}/100TeV){sup -1} year, contrary to the common assumption of toroidal magnetic fields with strong magnetic confinement. The model predicts a rather uniform Fermi LAT surface brightness out to {approx} 1{sup o} from the pulsar, in good agreement with the recently discovered LAT source centered 0.5{sup o} southwest of PSR J1826-1334 with extension 0.6 {+-} 0.1{sup o}.【 预 览 】
Files | Size | Format | View |
---|---|---|---|
1029129.pdf | 1491KB | download |