Be X射線聯星

Be X射線聯星是一種高質量X射線聯星,由一顆中子星和一顆Be星組成。通常中子星會以一個廣闊的橢圓軌道環繞着Be星,而Be星的星風亦多會形成一個與中子星軌道交錯的平面。每當中子星與Be星的星風相遇時,大量氣體便依附在中子星上。氣體會下沉到中子星並產生一股強烈的X射線[1]

LSI+61°303

LSI+61°303,亦即週期性伽瑪射線源CG135+01,有可能是這種聯星的例子。其每26.496天便會發出無線電波可见光紅外綫的波長變動週期亦為26.5天。[2]其緻密天體的質量未被準確測出,但推定它因其巨大質量並非中子星而是黑洞。[3]

英仙座X

英仙座X是由仙后座γ變星脈衝星組成的聯星,其X射線週期較長和較穩定。但也觀測到一些X射線的閃焰,相信是由於吸積盤的變動,但未有發現其與光學變動的關聯。[4]

至1996年達Be X射線聯星級別的20多個天體中惟LSI+61°303及英仙座X發出明顯較高光度及頻率的X射線(kT ≈ 10–20 keV,對比其他的kT ≤ 1 keV)。LSI+61°303亦發出強烈的無線電波,使其近似於其他短週期高質量X射線聯星。[2]

參考

  1. ^ Reig, Pablo. Be/X-ray binaries. Astrophysics and Space Science. 2011, 332: 1. Bibcode:2011Ap&SS.332....1R. arXiv:1101.5036 . doi:10.1007/s10509-010-0575-8. 
  2. ^ 2.0 2.1 Taylor AR, Young G, Peracaula M, Kenny HT, Gregory PC. An X-ray outburst from the radio emitting X-ray binary LSI+61°303. Astron Astrophys. 1996, 305: 817–24. Bibcode:1996A&A...305..817T. 
  3. ^ Taylor AR, Young G, Peracaula M, Kenny HT, Gregory PC. An X-ray outburst from the radio emitting X-ray binary LSI+61°303. Astron. Astrophys. 1996, 305: 817–24. Bibcode:1996A&A...305..817T. 
  4. ^ Massi, M; Migliari, S; Chernyakova, M. The black hole candidate LS I +61°0303. Monthly Notices of the Royal Astronomical Society. 2017, 468 (3): 3689. Bibcode:2017MNRAS.468.3689M. arXiv:1704.01335 . doi:10.1093/mnras/stx778.