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Chandra image of 47 Tuc W, a double star system consisting of a normal star and a neutron star
Credit: X-ray: NASA/CXC/CfA/J.Grindlay & C.Heinke; Optical: ESO/Danish 1.54-m/W.Keel et al.


ChandraXX: Hunting Pulsars in Globular Clusters

Over the past 20 years, the exceptional ability of the Chandra X-ray Observatory to create high spatial resolution X-ray images has enabled key advances in our understanding of the behavior of black holes and neutron stars. For example, a longstanding, important question is why some subset of neutron stars, the millisecond pulsars, rotate so rapidly - hundreds of times per second. These are the most rapidly spinning objects in the known Universe, but why they spin so rapidly is not obvious. Chandra's detection of X-ray emission from a millisecond pulsar called 47 Tuc W has provided important clues to help answer this question. This particular neutron star is in a globular cluster called 47 Tuc, a group of a few million stars bound together by gravity into a spherical ball about 100 lightyears across. The optical view of the stars in the cluster is shown in the left image above, while the image on the right shows the X-ray emitting cluster members seen by Chandra. The source marked by the arrow, 47 Tuc W, is an X-ray emitting neutron star which rotates on its axis more than 400 times per second. The combination of the X-ray images and X-ray variability from the Chandra observations with optical and radio data shows that this particular X-ray emitting pulsar is in a binary system, locked in orbit with a low mass star. This evidence indicates that accretion of matter from the companion star helps spin up millisecond pulsars to their extraordinary rotation rates.
Published: September 2, 2019


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Each week the HEASARC brings you new, exciting and beautiful images from X-ray and Gamma ray astronomy. Check back each week and be sure to check out the HEAPOW archive!
Page Author: Dr. Michael F. Corcoran
Last modified Monday, 09-Sep-2019 09:58:23 EDT