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

While the standard X-ray variability of black hole X-ray binaries (BHXBs) isstochastic and noisy, there are two known BHXBs that exhibit exotic`heartbeat'-like variability in their light curves: GRS 1915+105 and IGRJ17091-3624. In 2022, IGR J17091-3624 went into outburst for the first time inthe NICER/NuSTAR era. These exquisite data allow us to simultaneously track theexotic variability and the corresponding spectral features with unprecedenteddetail. We find that as in typical BHXBs, the outburst began in the hard state,then the intermediate state, but then transitioned to an exotic soft statewhere we identify two types of heartbeat-like variability (Class V and a newClass X). The flux-energy spectra show a broad iron emission line due torelativistic reflection when there is no exotic variability, and absorptionfeatures from highly ionized iron when the source exhibits exotic variability.Whether absorption lines from highly ionized iron are detected in IGRJ17091-3624 is not determined by the spectral state alone, but rather isdetermined by the presence of exotic variability; in a soft spectral state,absorption lines are only detected along with exotic variability. Our findingindicates that IGR J17091-3624 can be seen as a bridge between the mostpeculiar BHXB GRS 1915+105 and `normal' BHXBs because it alternates between theconventional and exotic behavior of BHXBs. We discuss the physical nature ofthe absorbing material and exotic variability in light of this new legacydataset.

The 2022 Outburst of IGR J17091-3624: Connecting the exotic GRS 1915+105 to standard black hole X-ray binaries