Download presentation
Presentation is loading. Please wait.
Published byHector Burkley Modified over 10 years ago
1
Pulsars Multi-Accelerator Radiation model Peking University
2
Outline n The difficulties of present pulsar models n The apocalypse from observation & theoretical research n A new acceleration region and a new model n Properties of this model n Comparing to observations
3
Pulsars + - - + Null surface 1.Strong magnetic field 2.Rapidly rotation Pulsar
4
Difficulties of present model There are two kinds of models For Polar Gap Model (Muslimov & Harding 2003) Require small inclination angle and impact angle For Outer Gap Model (Cheng et al 1986, 1994, 2000...) No off-pulse emission No Tev cut-off Too sharp rise of pulse profile We will solve these problem here.
5
Observation Note The radio pulse is narrow. The gamma-ray pulse is wide. Bridge emission Off pulse emission
6
Spectra Observation Cut-Off
7
The apocalypse from observation Pulse profile show: n The radio radiation comes from a compact region while gamma-ray radiation comes from a wide region Spectra show n Tev cut-off require the radiation location not far from the pulsar
8
The theory of pulsar radiation Polar Gap Model n Radiation locates at the magnetic pole of the pulsar Outer Gap Model n Radiation locates outside the null surface,far from the pulsar
9
Reasons for Difficulties of Present Model For Polar Gap Model Require small inclination angle and impact angle Reason n Too near For Outer Gap Model No off-pulse emission No Tev cut-off Too sharp rise of pulse profile Reason Too far
10
New Radiation Location n We note the so called Mid-Gap n It locates near than Outer Gap n Farther than Polar Gap
11
Input Physics 1. The radiation direction 2. The intensity of radiation 3. NOTE: only at this time! We will calculate the physics very soon.
12
Determine the Radiation Geometry
13
Abbreviation Correction n The abbreviation will affect the direction of radiation. V c c oo
14
The Calculation for the Radiation Map
15
Relative intensity
16
Radio? n We also consider the radio radiation in this region n Take the Inverse Compton Scatter model to calculate the radio radiation Have the intrinsic Beauty of Unification! n Not a machine made model
17
ICS model sketch map
18
Calculation for Radio Radiation
19
Unified Results Gamma Radio1 Radio2
20
The result of our model 1.Beam patterns 2.Pulse profile We have Bridge Emission Off-pulse Emission Soft rise and down Sight Line Vela
21
Vision
22
Multi-bands Fitting of Observations Vela Crab Geminga ICS model is used to give radio results Gamma-ray Radio
23
Predictions 1.Some pulsar could be only observed at certain bands 2.Some pulsar can be observed at many bands 3.Three components pulsar
24
Gamma-B Process n Gamma-B process 1.If the photons fly with some angle respect to the magnetic field 2.The photons have enough energy 3.Strong enough magnetic field The absorption ratio is Cm^-1
25
Geometry Condition
26
The Equation and Numeric Method n The Radiation Transfer Equation is rather hard to integrate. n Delta like and infinite integration
27
The Escape Membrane of the Photons Solve: To get the location of source
28
Spectra Result Tev cut-off Solve the spectra problem of outer gap Fit the crab
29
Our Work Study a new gamma-ray pulsar model with a new accelerator Investigate the possible acceleration mechanisms Discuss the physical and geometrical conditions of this region Discuss the spectra properties induced by gamma-B process Give the last escape membrane of photons. Compare our model with observation
30
Further Work Dynamic & Kinetic
31
Thanks
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.