UNIV SPACE RES ASSOC,HUNTSVILLE,AL 35806
; NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812
; UNIV ALABAMA,DEPT PHYS,HUNTSVILLE,AL 35899
; HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138
; UPS,CNRS,CTR ETUD SPATIALE RAYONNEMENTS,F-31028 TOULOUSE 04,FRANCE
; COLUMBIA UNIV,COLUMBIA ASTROPHYS LAB,NEW YORK,NY 10027
We report RXTE/PCA observations of 4U 1608-52 on March 15, 18, and 22 immediately after the outburst in early 1996. The persistent count rates ranged from 190 to 450 counts s(-1) (1-60 keV). During this period of time, 4U 1608-52 was in the island state. We detected quasi-periodic oscillation (QPO) features in the power density spectra (PDS) at 567-800 Hz on March 15 and 22, with source fractional root mean square (rms) amplitude of 13%-17% and widths of 78-180 Hz. The average rms amplitude of these QPO features is positively correlated with the energy. Our results imply that the neutron star spin frequency is possibly between 300 and 365 Hz.
Yu, W,Zhang, SN,Harmon, BA,et al. kHz quasi-periodic oscillation in island state of 4U 1608-52 as observed with RXTE/PCA[J]. ASTROPHYSICAL JOURNAL,1997,490(2):L153-L156.
Yu, W.,Zhang, SN.,Harmon, BA.,Paciesas, WS.,Robinson, CR.,...&Kaaret, P.(1997).kHz quasi-periodic oscillation in island state of 4U 1608-52 as observed with RXTE/PCA.ASTROPHYSICAL JOURNAL,490(2),L153-L156.
Yu, W,et al."kHz quasi-periodic oscillation in island state of 4U 1608-52 as observed with RXTE/PCA".ASTROPHYSICAL JOURNAL 490.2(1997):L153-L156.