A PROPELLER-EFFECT INTERPRETATION OF MAXI/GSC LIGHT CURVES OF 4U 1608-52 AND Aql X-1 AND APPLICATION TO XTE J1701-462

作者：Asai K^*; Matsuoka M; Mihara T; Sugizaki M; Serino M; Nakahira S; Negoro H; Ueda Y; Yamaoka K

来源：Astrophysical Journal, 2013, 773(2): 117.

DOI：10.1088/0004-637X/773/2/117

• stars: neutron
• X-rays: binaries
• X-rays: individual (Aql X-1, 4U 1608-52, XTE J1701-462)

We present the luminosity dwell-time distributions during the hard states of two low-mass X-ray binaries containing a neutron star (NS), 4U 1608-52 and Aql X-1, observed with MAXI/GSC. The luminosity distributions show a steep cutoff on the low-luminosity side at similar to 1.0 x 10(36) erg s(-1) in both sources. The cutoff implies a rapid luminosity decrease in their outburst decay phases and this decrease can be interpreted as being due to the propeller effect. We estimate the surface magnetic field of 4U 1608-52 to be (0.5-1.6) x 10(8) G and Aql X-1 to be (0.6-1.9) x 10(8) G from the cutoff luminosity and apply the same propeller mechanism to the similar rapid luminosity decrease observed in the transient Z source, XTE J1701-462, with RXTE/ASM. Assuming that the spin period of the NS is on the order of milliseconds, the observed cutoff luminosity implies a surface magnetic field on the order of 10(9) G.

• 出版日期2013-8-20