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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We report detection of a very bright X-ray-UV-optical outburst of OJ 287 inApril-June 2020; the second brightest since the beginning of our Swiftmulti-year monitoring in late 2015. It is shown that the outburst ispredominantly powered by jet emission. Optical-UV-X-rays are closelycorrelated, and the low-energy part of the XMM-Newton spectrum displays anexceptionally soft emission component consistent with a synchrotron origin. Amuch harder X-ray powerlaw component (Gamma-x = 2.4, still relatively steepwhen compared to expectations from inverse-Compton models) is detected out to70 keV by NuSTAR. We find evidence for reprocessing around the Fe region,consistent with an absorption line. If confirmed, it implies matter in outflowat approx 0.1c. The multi-year Swift lightcurve shows multiple episodes offlaring or dipping with a total amplitude of variability of a factor of 10 inX-rays, and 15 in the optical-UV. The 2020 outburst observations are consistentwith an after-flare predicted by the binary black hole model of OJ 287, wherethe disk impact of the secondary black hole triggers time-delayed accretion andjet activity of the primary black hole.

The April-June 2020 super-outburst of OJ 287 and its long-term  multiwavelength light curve with Swift: binary supermassive black hole and  jet activity