Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-04-25
Astronomy and Astrophysics
Astrophysics
5 pages of text and 4 figures (submitted to Astrophysical Journal)
Scientific paper
10.1086/590551
The evolution leading to the formation of a neutron star in the very young Westerlund 1 star cluster is investigated. The turnoff mass has been estimated to be 35 Msun, indicating a cluster age ~ 3-5 Myr. The brightest X-ray source in the cluster, CXO J164710.2-455216, is a slowly spinning (10 s) single neutron star and potentially a magnetar. Since this source was argued to be a member of the cluster, the neutron star progenitor must have been very massive (M_zams > 40 Msun) as noted by Muno et al. (2006). Since such massive stars are generally believed to form black holes (rather than neutron stars), the existence of this object poses a challenge for understanding massive star evolution. We point out while single star progenitors below M_zams < 20 Msun form neutron stars, binary evolution completely changes the progenitor mass range. In particular, we demonstrate that mass loss in Roche lobe overflow enables stars as massive as 50-80 Msun, under favorable conditions, to form neutron stars. If the very high observed binary fraction of massive stars in Westerlund 1 (> 70 percent) is considered, it is natural that CXO J164710.2-455216 was formed in a binary which was disrupted in a supernova explosion such that it is now found as a single neutron star. Hence, the existence of a neutron star in a given stellar population does not necessarily place stringent constraints on progenitor mass when binary interactions are considered. It is concluded that the existence of a neutron star in Westerlund 1 cluster is fully consistent with the generally accepted framework of stellar evolution.
Belczynski Krzysztof
Taam Ronald
No associations
LandOfFree
The most massive progenitors of neutron stars: CXO J164710.2-455216 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The most massive progenitors of neutron stars: CXO J164710.2-455216, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The most massive progenitors of neutron stars: CXO J164710.2-455216 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-728191