2011/07/07 by J. F. Dolan, Dolan, J. F.
Chemistry · Engineering · Physics and Astronomy · #FOS: Physical sciences #Gyrotron and Vacuum Electronics Research #High Energy Astrophysical Phenomena (astro-ph.HE) #Inorganic Fluorides and Related Compounds #Laser Design and Applications
paper · pdf · doi:10.48550/arxiv.1107.1537
openalex publication_date 2011/07/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Very low frequency (ν ~ 1.9 mHz) quasi-periodic oscillations (QPO) have been detected in 2 - 60 keV X-rays from 4U1700-37 using auto-correlation function analysis of RXTE archival data. No pulsar signal was detected in the data. Less than 0.5% of the flux from the source (3σ upper limit) is coherently pulsed with a period between 250 ms and 40 s. This upper limit corresponds to a pulsed flux <0.02 mJy. The existence of QPO in 4U1700-37 and the lack of a detected pulsar indicates that the X-ray source is more likely to be a black hole than a neutron star, consistent with recent mass estimates.