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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We measure the spin of XTE J1550−564 using the two leading methods: (i) modelling the thermal continuum spectrum of the accretion disc; and (ii) modelling the broad red wing of the reflection fluorescence Fe Kα line. We find that these two independent measurements of spin are in agreement. For the continuum‐fitting analysis, we use a data sample consisting of several dozen  Rossi X‐ray Timing Explorer  spectra, and for the Fe Kα analysis, we use a pair of  ASCA  spectra from a single epoch. Our spin estimate for the black hole primary using the continuum‐fitting method is −0.11 &lt;  a  *  &lt; 0.71 (90 per cent confidence), with a most likely spin of  a  * = 0.34. In obtaining this result, we have thoroughly explored the dependence of the spin value on a wide range of model‐dependent systematic errors and observational errors; our precision is limited by uncertainties in the distance and orbital inclination of the system. For the Fe‐line method, our estimate of spin is  a  * = 0.55 +0.15  − 0.22 . Combining these results, we conclude that the spin of this black hole is moderate,  a  * = 0.49 +0.13  − 0.20 , which suggests that the jet activity of this microquasar is powered largely by its accretion disc rather than by the spin energy of the black hole.

The spin of the black hole microquasar XTE J1550−564 via the continuum‐fitting and Fe‐line methods