logging in or signing up Qiaogj Junyo Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINTLite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 38 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: November 14, 2007 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Qiao,G.J. Dept. of Astronomy, Peking Univ. : Qiao,G.J. Dept. of Astronomy, Peking Univ. Radio and Gamma-ray emission from pulsarsSlide2: Collaborators: Zhang, B.(University of Nevada), Xu, R.X.(PKU), Han,J.L.(NAOC), Lin,W.P.(SHO), Liu,G.F.(CFA, Harvard) Xue,Y.Q.(Purdue Univ. ) Wang,H.G.(CFA , GuangzhouUniversity), Lee,K.J.(PKU)Slide3: Pulsars are discovered 40 years Key problems： The nature of PSR：NS & Quark stars ? Radiation：radiation mechanisms？ Polar gaps? Outer gaps？ or … Annular gaps？ Slide4: Observations Radio Gamma-ray Annular gap Polar gap Theories Narrow Wide Outer gap Spect; Cut wide Plausible §1.Radio obs. & theories: Sparking; annular emission §2.The magnetosphere & acceleration polar gap; outer gap §3.Annular gap §4.Free flow: slot gap & Annular gap : §1.Radio obs. & theories: Sparking; annular emission §2.The magnetosphere & acceleration polar gap; outer gap §3.Annular gap §4.Free flow: slot gap & Annular gap Radio and Gamma-ray radiation of pulsars Emission beams: Emission beams Rankin, 1983, ApJ,274,333 Manchester,R.N. 1995 J. Astroph. Astr. 16,107 Core emission ! Slide7: Emission beams in RS model Ruderman & Sutherland, 1975 Emission beams Hollow cone only! Low freq: wide beam! Slide8: RS model Qiao,Liu, Zhang,& Han, 2001,AA Lyne & Manchester (1988) & Sieber et al. (1975),Kramer,(1994) There are various beam width- frequency relations, which can not be simple explained by RS model. ?ICS Model: emission beams ⇒ Core +cones: ICS Model: emission beams ⇒ Core +cones Qiao, 1992 Qiao & Lin, A&A,1998Slide10: Zhang, Qiao, Han, Lee, Wang , AA,2007 Different components of same frequency come from different altitudes.Slide11: Polarization: Beam shift→PA jumps Xu, Qiao & Han, 1997, AA Slide12: Zhang,Qiao,Lin,Han, 1997 Rankin, 1986Slide13: Mode change pulsars Zhang,Qiao,Lin,Han, 1997,ApJ Zhang,Qiao, Han, 1997,ApJ §1.Radio obs. & theories: Sparking; annular emission §2.The magnetosphere & acceleration polar gap; outer gap §2.Annular gap §3.Free flow: slot gap & Annular gap : §1.Radio obs. & theories: Sparking; annular emission §2.The magnetosphere & acceleration polar gap; outer gap §2.Annular gap §3.Free flow: slot gap & Annular gap Radio and Gamma-ray radiation of pulsarsSlide15: The magnetosphere of a NS For Crab Pulsar: Goldreich & Julian, 1969,ApJ,157,869 1. Gap：inner gap & outer gap 2. Space Charge Limited Flow: Polar cap; Slot gap 3. Annular gap: 1. Gap：inner gap & outer gap 2. Space Charge Limited Flow: Polar cap; Slot gap 3. Annular gap The annular gap: the important regionBasic Observational facts: Basic Observational facts David J. Thompson:astro-ph/0312272 Slide18: For inner gap Phase resolved spectrum, bridge is hard 1e1~1e3 Gev cut-off For outer gap Wide beams Thompson, astro-ph/0312272 , Kanbach, 2002,astro-ph/0209021§1.Radio obs. & theories: Sparking; annular emission §2.The magnetosphere & acceleration polar gap; outer gap §3.Annular gap §4.Free flow: slot gap & Annular gap : §1.Radio obs. & theories: Sparking; annular emission §2.The magnetosphere & acceleration polar gap; outer gap §3.Annular gap §4.Free flow: slot gap & Annular gap Radio and Gamma-ray radiation of pulsarsSlide20: Two polar cap regions Core region Annular region Outer gapSlide21: The Inner Annular Gap Qiao,Lee,Wang,Xu, 2004a, ApJL The radio and gamma-ray can be understood by annular gap at same time.Slide22: Mclaughlin 2003,astr-ph/0310454 Bi-drifting: Obs.Slide23: Accelerators: Inner vacuum gap (Ruderman & Sutherland 1975) requiring high binding energy of charges on stellar surface Drifting sub-pulses Xu,Qiao Zhang, 1999,ApJL,522,L112 Deshpannde & Rankin, 1999,ApJ, 524,1008Inner Annular Gap :: Inner Annular Gap : Bi-drifting: fitting: Bi-drifting: fitting Mclaughlin 2003,astr-ph/0310454 Qiao,Lee,Zhang,Xu,Wang,2004b, ApJL§1.The magnetosphere & acceleration polar gap: phase resolute spectrum，cut off outer gap: gamma-ray wide beam §2.Annular gap §3.Free flow: slot gap & Annular gap §4.Radio obs. & theories: Sparking; annular emission : §1.The magnetosphere & acceleration polar gap: phase resolute spectrum，cut off outer gap: gamma-ray wide beam §2.Annular gap §3.Free flow: slot gap & Annular gap §4.Radio obs. & theories: Sparking; annular emission Radio and Gamma-ray radiation of pulsarsThe annular flow accelerator --Can particles be accelerated in the annular region (the non-vacuum gap cases)?: The annular flow accelerator --Can particles be accelerated in the annular region (the non-vacuum gap cases)? Qiao,Lee,Zhang,Wang,Xu, astro-ph/0704.3801The annular gap: The annular gap the annular gap must be taking into account! ⇒Slide29: Pulsars: NS or Quark stars ? Free flow: sparking or not ? Free flow: can produce drifting sub-pulse? Annular gap & others: Obs. Test? Future obs. & theories Slide30: PSR B1055-52 : observational constraintsPosition angle sweep fit with Rotation Vector Model: ~157o Position angle sweep fit with Rotation Vector Model Lyne & Manchester 1988 Inclination Angle a Viewing Angle z a Line of Sight W m z Pole A (MP) Pole B (IP) MP IP Double-pole origin Wang et al.2005Slide32: PSR B1055-52 : observational constraints 1). Inclination angle a=74.7 dgree 2). Viewing angle z =114 dgree Slide33: Thompson et al. 1992 Radio Observed emission beams Gamma-raySlide34: Observed emission beams Wang et al.2005 From observation, the radiation location can be determined uniquely for this star.Slide35: Annular emission model Wang et al.2005 The observations show that the radiation position locates in the annular region.Slide36: Thank you ! Spark Model: Spark Model Gil & Sendyk, 2000 Qiao & Lin, A&A,1998: Qiao & Lin, A&A,1998 ICS: shift of emission beams Different emission location→shift of the emission beamsSlide39: ω=2γ2ω0(1-βCosθi) The Inverse Compton Scattering (ICS) model Qiao & Lin,1998, A&ASlide40: Polarization of integrated pulse in ICS （Xu et al. ApJ.2000 ） V—circular poln L—Linear poln I—Total Intensity Position angleSlide41: Polarization: PA jump Xu, Qiao & Han, 1997, AA Xu et al. ApJ. 2000: Polarization of Individual pulses in ICS model Xu et al. ApJ. 2000 Pulsar radiation : Pulsar radiation Radio: w/P∼3-4% Gamma-ray: Two pulses & very wideSlide44: “S” shape PA & Obs. → The radiation location: near surfaceThe annular gap: The annular gapSlide46: Drifting subpulses PULSE LONGITUDE Drifting subpulses Taylor et al. (1975) Backer (1973)Slide47: Slot gap Slot gap model: Slot gap model Arons,J. 1983, ApJSlide49: McCullon et al. 1976 Observation at radio band Slide50: Obs. Obs. You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
Qiaogj Junyo Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINTLite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 38 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: November 14, 2007 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Qiao,G.J. Dept. of Astronomy, Peking Univ. : Qiao,G.J. Dept. of Astronomy, Peking Univ. Radio and Gamma-ray emission from pulsarsSlide2: Collaborators: Zhang, B.(University of Nevada), Xu, R.X.(PKU), Han,J.L.(NAOC), Lin,W.P.(SHO), Liu,G.F.(CFA, Harvard) Xue,Y.Q.(Purdue Univ. ) Wang,H.G.(CFA , GuangzhouUniversity), Lee,K.J.(PKU)Slide3: Pulsars are discovered 40 years Key problems： The nature of PSR：NS & Quark stars ? Radiation：radiation mechanisms？ Polar gaps? Outer gaps？ or … Annular gaps？ Slide4: Observations Radio Gamma-ray Annular gap Polar gap Theories Narrow Wide Outer gap Spect; Cut wide Plausible §1.Radio obs. & theories: Sparking; annular emission §2.The magnetosphere & acceleration polar gap; outer gap §3.Annular gap §4.Free flow: slot gap & Annular gap : §1.Radio obs. & theories: Sparking; annular emission §2.The magnetosphere & acceleration polar gap; outer gap §3.Annular gap §4.Free flow: slot gap & Annular gap Radio and Gamma-ray radiation of pulsars Emission beams: Emission beams Rankin, 1983, ApJ,274,333 Manchester,R.N. 1995 J. Astroph. Astr. 16,107 Core emission ! Slide7: Emission beams in RS model Ruderman & Sutherland, 1975 Emission beams Hollow cone only! Low freq: wide beam! Slide8: RS model Qiao,Liu, Zhang,& Han, 2001,AA Lyne & Manchester (1988) & Sieber et al. (1975),Kramer,(1994) There are various beam width- frequency relations, which can not be simple explained by RS model. ?ICS Model: emission beams ⇒ Core +cones: ICS Model: emission beams ⇒ Core +cones Qiao, 1992 Qiao & Lin, A&A,1998Slide10: Zhang, Qiao, Han, Lee, Wang , AA,2007 Different components of same frequency come from different altitudes.Slide11: Polarization: Beam shift→PA jumps Xu, Qiao & Han, 1997, AA Slide12: Zhang,Qiao,Lin,Han, 1997 Rankin, 1986Slide13: Mode change pulsars Zhang,Qiao,Lin,Han, 1997,ApJ Zhang,Qiao, Han, 1997,ApJ §1.Radio obs. & theories: Sparking; annular emission §2.The magnetosphere & acceleration polar gap; outer gap §2.Annular gap §3.Free flow: slot gap & Annular gap : §1.Radio obs. & theories: Sparking; annular emission §2.The magnetosphere & acceleration polar gap; outer gap §2.Annular gap §3.Free flow: slot gap & Annular gap Radio and Gamma-ray radiation of pulsarsSlide15: The magnetosphere of a NS For Crab Pulsar: Goldreich & Julian, 1969,ApJ,157,869 1. Gap：inner gap & outer gap 2. Space Charge Limited Flow: Polar cap; Slot gap 3. Annular gap: 1. Gap：inner gap & outer gap 2. Space Charge Limited Flow: Polar cap; Slot gap 3. Annular gap The annular gap: the important regionBasic Observational facts: Basic Observational facts David J. Thompson:astro-ph/0312272 Slide18: For inner gap Phase resolved spectrum, bridge is hard 1e1~1e3 Gev cut-off For outer gap Wide beams Thompson, astro-ph/0312272 , Kanbach, 2002,astro-ph/0209021§1.Radio obs. & theories: Sparking; annular emission §2.The magnetosphere & acceleration polar gap; outer gap §3.Annular gap §4.Free flow: slot gap & Annular gap : §1.Radio obs. & theories: Sparking; annular emission §2.The magnetosphere & acceleration polar gap; outer gap §3.Annular gap §4.Free flow: slot gap & Annular gap Radio and Gamma-ray radiation of pulsarsSlide20: Two polar cap regions Core region Annular region Outer gapSlide21: The Inner Annular Gap Qiao,Lee,Wang,Xu, 2004a, ApJL The radio and gamma-ray can be understood by annular gap at same time.Slide22: Mclaughlin 2003,astr-ph/0310454 Bi-drifting: Obs.Slide23: Accelerators: Inner vacuum gap (Ruderman & Sutherland 1975) requiring high binding energy of charges on stellar surface Drifting sub-pulses Xu,Qiao Zhang, 1999,ApJL,522,L112 Deshpannde & Rankin, 1999,ApJ, 524,1008Inner Annular Gap :: Inner Annular Gap : Bi-drifting: fitting: Bi-drifting: fitting Mclaughlin 2003,astr-ph/0310454 Qiao,Lee,Zhang,Xu,Wang,2004b, ApJL§1.The magnetosphere & acceleration polar gap: phase resolute spectrum，cut off outer gap: gamma-ray wide beam §2.Annular gap §3.Free flow: slot gap & Annular gap §4.Radio obs. & theories: Sparking; annular emission : §1.The magnetosphere & acceleration polar gap: phase resolute spectrum，cut off outer gap: gamma-ray wide beam §2.Annular gap §3.Free flow: slot gap & Annular gap §4.Radio obs. & theories: Sparking; annular emission Radio and Gamma-ray radiation of pulsarsThe annular flow accelerator --Can particles be accelerated in the annular region (the non-vacuum gap cases)?: The annular flow accelerator --Can particles be accelerated in the annular region (the non-vacuum gap cases)? Qiao,Lee,Zhang,Wang,Xu, astro-ph/0704.3801The annular gap: The annular gap the annular gap must be taking into account! ⇒Slide29: Pulsars: NS or Quark stars ? Free flow: sparking or not ? Free flow: can produce drifting sub-pulse? Annular gap & others: Obs. Test? Future obs. & theories Slide30: PSR B1055-52 : observational constraintsPosition angle sweep fit with Rotation Vector Model: ~157o Position angle sweep fit with Rotation Vector Model Lyne & Manchester 1988 Inclination Angle a Viewing Angle z a Line of Sight W m z Pole A (MP) Pole B (IP) MP IP Double-pole origin Wang et al.2005Slide32: PSR B1055-52 : observational constraints 1). Inclination angle a=74.7 dgree 2). Viewing angle z =114 dgree Slide33: Thompson et al. 1992 Radio Observed emission beams Gamma-raySlide34: Observed emission beams Wang et al.2005 From observation, the radiation location can be determined uniquely for this star.Slide35: Annular emission model Wang et al.2005 The observations show that the radiation position locates in the annular region.Slide36: Thank you ! Spark Model: Spark Model Gil & Sendyk, 2000 Qiao & Lin, A&A,1998: Qiao & Lin, A&A,1998 ICS: shift of emission beams Different emission location→shift of the emission beamsSlide39: ω=2γ2ω0(1-βCosθi) The Inverse Compton Scattering (ICS) model Qiao & Lin,1998, A&ASlide40: Polarization of integrated pulse in ICS （Xu et al. ApJ.2000 ） V—circular poln L—Linear poln I—Total Intensity Position angleSlide41: Polarization: PA jump Xu, Qiao & Han, 1997, AA Xu et al. ApJ. 2000: Polarization of Individual pulses in ICS model Xu et al. ApJ. 2000 Pulsar radiation : Pulsar radiation Radio: w/P∼3-4% Gamma-ray: Two pulses & very wideSlide44: “S” shape PA & Obs. → The radiation location: near surfaceThe annular gap: The annular gapSlide46: Drifting subpulses PULSE LONGITUDE Drifting subpulses Taylor et al. (1975) Backer (1973)Slide47: Slot gap Slot gap model: Slot gap model Arons,J. 1983, ApJSlide49: McCullon et al. 1976 Observation at radio band Slide50: Obs. Obs.