oscillation driven magnetospheric activity in pulsars
DESCRIPTION
Peking University Mengxiang Lin , Renxin Xu, Bing Zhang Email: [email protected] 2014.10.21 Submitted to Astrophysical Journal. Oscillation Driven Magnetospheric Activity In Pulsars. Outline. Introduction Physical model Results Explanation of radio AXPs/SGRs Summary. - PowerPoint PPT PresentationTRANSCRIPT
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Oscillation Driven Magnetospheric Activity In Pulsars
Peking University Mengxiang Lin, Renxin Xu, Bing ZhangEmail: [email protected]
Submitted to Astrophysical Journal
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Outline
Introduction Physical model Results Explanation of radio AXPs/SGRs Summary
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Introduction
Pulsars:rotational magnetized compact
objects
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Introduction
Glitches (sudden “spin-up”) are common
Radio AXPs/SGRs (four sources detected)
(mcGill online magnetar catalog) Quiescent states: radio quiet After outbursts: radio loud
AXPs/SGRs: anomalous X-ray pulsars / soft gamma-ray repeaters
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Morozova et al. (2010); Zanotti et al. (2012) had studied oscillations’ effect under SCLF model
We study oscillations’ effect under inner gap model
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The Physical Model
G-J charge density and toroidal oscillation modification
Unipolar induction:Goldreich-Julian charge density:(Goldreich & Julian 1969, only rotation)
Toroidal oscillation:
Oscillation modification to G-J charge density:
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The Physical Model
Inner gap model
Death line criterion :
Ruderman & Satherland (1975)
Three modes: CR (curvature radiation)ICS (inverse Compton
scattering)2 (two-photon annihilation)
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Results
Typical parameters of normal pulsars: s, G, K, dipole
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Explanation of radio AXPs/SGRs
Superstrong magnetic field : always above the radio death line
Oscillations :enlarge radio emission beamenlarge the possibility to be
detected
In magnetar model
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Explanation of radio AXPs/SGRs
Normal magnetic field Quiescent states
under death line radio quiet After outbursts:
Starquakes oscillations larger above death line radio loud
Radio decays with oscillations damping
In solid quark star model
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Explanation of radio AXPs/SGRs
Tong & Wang 2014
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Explanation of radio AXPs/SGRs
In solid quark star model
Explanation of 1E 1547.0-5408:
s, G, K
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Explanation of radio AXPs/SGRs
In solid quark star model
The critical K of the four radio AXPs/SGRs. Dipole magnetic field with G is adopted.
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Summary
Toroidal oscillations change and then influence the properties of pulsar inner gap Shorter height, Larger Larger effective polar cap Mode change
Explanation of radio AXPs/SGRs Magnetar model: larger radio beam Solid quark star model: larger activate the
pulsar inner gap from below the radio death line
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The Physical Model
The height of gap in three modes
CR, ICS ,
Case 1: If : Case 2: If :
or
𝛾𝑒,𝑚𝑎𝑥=𝑒 Δ𝑉 /(𝑚𝑒𝑐2)
↑ ↑ ↓
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The Physical Model
The height of gap in three modes
Two photon annihilation
(Zhang et al. 1998)
only depends on Temperature