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Joined 2026-09-21 Message
Incoming links: Rossi X-ray Timing Explorer
Michiel van der Klis Created 2026-10-20 Updated 2026-11-05
Michiel van der Klis uses rapid X-ray variability to study compact accreting systems. With Rudy Wijnands, he discovered persistent 2.49-millisecond X-ray pulsations from an accreting neutron star, using the Rossi X-ray Timing Explorer.
Such a coherent pulse train provides a much more direct rotational clock than a broad or drifting variability peak. The 1998 discovery connected accretion in an X-ray binary with the proposed spinning-up of a neutron star into a millisecond pulsar, providing a missing observational link in that evolutionary picture.[ref]
Discovery of the first accretion-powered millisecond X-ray pulsar by Rudy Wijnands and Michiel van der Klis. Abstract: persistent pulsations, observing instrument and connection to recycled radio pulsars
Portrait of Michiel van der Klis
. Schrijver; own work, 7 June 2004; uploaded by Schrijver~commonswiki. CC BY 3.0, via Wikimedia Commons. Source.
Rossi X-ray Timing Explorer 2026-11-05
The Rossi X-ray Timing Explorer was a space observatory designed to measure rapid X-ray variability, operating from its 1995 launch until 2012. Its time-resolved observations probed accretion and rotation around compact objects such as neutron stars and black holes.
Fast event timing complements an energy spectrum. A narrow feature in a temporal power spectrum identifies an oscillation or rotation frequency of the source, not the frequency of an individual X-ray photon. Comparing such timing features with changes in spectral shape helps distinguish physical states of an accreting system.[ref]
The Rossi X-ray Timing Explorer by NASA. Mission lifetime and compact-source timing goals