A MAGNETAR-LIKE EVENT FROM LS I +61 Degree-Sign 303 AND ITS NATURE AS A GAMMA-RAY BINARY

Journal Article · Tue Jan 10 04:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/744/2/106· OSTI ID:22004255

Torres, Diego F; Rea, Nanda ^[1]; Esposito, Paolo ^[2]; Jian, Li; Yupeng, Chen; Shu, Zhang ^[3]

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1. Institut de Ciencies de l'Espai (IEEC-CSIC), Campus UAB, Torre C5, 2a planta, 08193 Barcelona (Spain)
2. INAF, Osservatorio Astronomico di Cagliari, localita Poggio dei Pini, strada 54, I-09012 Capoterra (Italy)
3. Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049 (China)

We report on the Swift Burst Alert Telescope detection of a short burst from the direction of the TeV binary LS I +61 Degree-Sign 303, resembling those generally labeled as magnetar-like. We show that it is likely that the short burst was indeed originating from LS I +61 Degree-Sign 303 (although we cannot totally exclude the improbable presence of a far-away, line-of-sight magnetar) and that it is a different phenomenon with respect to the previously observed ks-long flares from this system. Accepting the hypothesis that LS I +61 Degree-Sign 303 is the first magnetar detected in a binary system, we study those implications. We find that a magnetar-composed LS I +61 Degree-Sign 303 system would most likely be (i.e., for the usual magnetar parameters and mass-loss rate) subject to a flip-flop behavior, from a rotationally powered regime (in the apastron) to a propeller regime (in the periastron) along each of the LS I +61 Degree-Sign 303 eccentric orbital motion. We prove that, unlike near an apastron, where an interwind shock can lead to the normally observed LS I +61 Degree-Sign 303 behavior, during TeV emission the periastron propeller is expected to efficiently accelerate particles only to sub-TeV energies. This flip-flop scenario would explain the system's behavior when a recurrent TeV emission only appears near the apastron, the anti-correlation of the GeV and TeV emission, and the long-term TeV variability (which seems correlated to LS I +61 Degree-Sign 303's super-orbital period), including the appearance of a low TeV state. Finally, we qualitatively put the multi-wavelength phenomenology into the context of our proposed model and make some predictions for further testing.

• OSTI ID: 22004255
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 744; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
EMISSION
GAMMA RADIATION
STARS
TELESCOPES
WAVELENGTHS