English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Monitoring the cooling of neutron-star crusts heated during accretionoutbursts allows us to infer the physics of the dense matter present in thecrust. We examine the crust cooling evolution of the low-mass X-ray binary MXB1659-29 up to ~505 days after the end of its 2015 outburst (hereafter outburstII) and compare it with what we observed after its previous 1999 outburst(hereafter outburst I) using data obtained from the Swift, XMM-Newton, andChandra observatories. The observed effective surface temperature of theneutron star in MXB 1659-29 dropped from ~92 eV to ~56 eV from ~12 days to ~505days after the end of outburst II. The most recently performed observationafter outburst II suggests that the crust is close to returning to thermalequilibrium with the core. We model the crust heating and cooling for both itsoutbursts collectively to understand the effect of parameters that may changefor every outburst (e.g., the average accretion rate, the length of outburst,the envelope composition of the neutron star at the end of the outburst) andthose which can be assumed to remain the same during these two outbursts (e.g.,the neutron star mass, its radius). Our modelling indicates that all parameterswere consistent between the two outbursts with no need for any significantchanges. In particular, the strength and the depth of the shallow heatingmechanism at work (in the crust) were inferred to be the same during bothoutbursts, contrary to what has been found when modelling the cooling curvesafter multiple outburst of another source, MAXI J0556-332. This difference insource behaviour is not understood. We discuss our results in the context ofour current understanding of cooling of accretion-heated neutron-star crusts,and in particular with respect to the unexplained shallow heating mechanism.

Consistent accretion-induced heating of the neutron-star crust in MXB 1659-29 during two different outbursts