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

The Sagittarius B2 (Sgr B2) molecular cloud complex is an X-ray reflectionnebula whose total emissions have continued to decrease since 2001 as itreprocesses one or more past energetic outbursts from the supermassive blackhole Sagittarius A*. The X-ray reflection model explains the observed timevariability and provides a window into the luminous evolutionary history of ournearest supermassive black hole. In light of evidence of elevated cosmicparticle populations in the Galactic Center, X-rays from Sgr B2 are also ofinterest as a probe of low-energy (sub-GeV) cosmic rays, which may beresponsible for an increasing relative fraction of the nonthermal X-rayemission as the contribution from X-ray reflection decreases. Here, we presentthe most recent deep NuSTAR and XMM-Newton observations of Sgr B2, from 2018.These reveal small-scale variations within lower-density portions of thecomplex, including brightening features, yet still enable upper limits onX-rays from low-energy cosmic particle interactions in Sgr B2. We present FeK$\alpha$ fluxes from cloud regions of different densities, facilitatingcomparison with models of ambient LECR interactions throughout the cloud.

New Constraints on Cosmic Particle Populations at the Galactic Center using X-ray Observations of the Molecular Cloud Sagittarius B2