Is PSR B0943 10 a lowmass quark star

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Is PSR B094310 a low-mass quark star?

• Youling Yue(???), Xiaohong Cui(???)
• and Renxin Xu(???)
• Astronomy department, Peking University
• at Nanjing 2006.8

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contents

• Pulsar, neutron star, quark star
• PSR B094310, quark star model, inclination angle
  effect
• Conclusion

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What is pulsar

• Neutron star
• Normal or Mixed/hybrid (quark core)
• Quark star
• Bare or with thin crust
• Solid (stronger GW emission?) or fluid
• Which one(s)??Observation

Bejger and Haensel 2003
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Bejger and Haensel 2003
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PSR B094310 (P 1 s), one of the best-studied
drifting pulsar
Deshpande Rankin 1999
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• We focus on pulsar sub-pulse drifting and polar
  gap model

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Pulsar emission models

• polar gap (e.g., Ruderman Sutherland 1975/RS75)
  successful to sub-pulse drifting
• space charge-limited flow (e.g., Arons
  Scharlemenn 1979)
• outer gap (e.g., Cheng et al. 1986)
• core gap and annular gap (e.g., Qiao et al.
  2004)

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Success of polar gap model (RS75)
e
e-
RS75
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Edwards and Stappers 2002
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To test the model
earth
hot spot In x-ray band
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• X-ray band observation (Zhang et al. 2005)
• A_polar 103 m2 (observation)
• A_polar 6x104 m2 (theory, for R10 km pulsar)

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Zhang et al. 2005
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To solve the problem

• modification of polar gap model
• a low mass bare strange quark star
• small radius (R 2.6 km to fit the observation)
• No binding energy problembinding energy of ion
  is nearly infinity (Xu Qiao 1999)

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advantages

• RS75
• Only work when
• the binding energy problem, need strong B
• Our model
• Work for both
• Quark star has strong enough binding energy
  (binding by strong interaction)

gt 0
lt 0 and
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Problems from potential drop

• Philt 1012 V (critical potential drop)

Last open field line
0
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Considering inclination angle
0
Last open field line
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Results
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Inclination angle
In the parameter space
rho 2rho_n
A 103 m2
Phi is well above 1012 V
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conclusion

• PSR B094310 could be a quark star.
• The potential drop will be 100 times larger when
  considering inclination angle effects.

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• Thank you

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Deshpande Rankin 2001