Intermittent dipping in an LMXB
Some years ago I noticed a peculiar
dip in the X-ray
intensity of a well-known transient,
Aql X-1.
Such dips have been seen from other systems, but there they occur once each
orbital period, and are generally explained by material in the outer
accretion disc coming into sight once each orbital period, and (partially)
blocking the view of the neutron star.
With the help of Honours sudents James Upjohn and Matthew Stuart, and
vacation student Alishan Ajamyan, we made an exhaustive search of the available
RXTE
data on the source, and turned up another dip, six years earlier.
We explained the behaviour as a new kind of "intermittent" dipping, which
— due to it's apparent rarity — could be detectable in several tens
of other systems. Our paper has now been published in MNRAS.
Labels: 2016, /transients