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

The question of the origin of the hard X-ray/soft gamma-ray emission inCentaurus A (Cen A) persists despite decades of observations. Results fromX-ray instruments suggest a jet origin since the implied electron temperature(kT_e) would cause pair production runaway in the corona. In contrast,instruments sensitive to soft gamma-rays report electron temperaturesindicating a corona origin may be possible. In this context, we analyzedarchival INTEGRAL/IBIS-ISGRI and SPI data and observations from a 2022 Cen Amonitoring program. Our analysis did not find any spectral variability. Thus wecombined all observations for long-term average spectra, which were fit with aNuSTAR observation to study the 3.5 keV - 2.2 MeV spectrum. Spectral fits usinga CompTT model found kT_e ~ 550 keV, near pair-production runaway. The spectrumwas also well described by a log-parabola to model synchrotron self-Comptonemission from the jet. Additionally, a spectral fit with the 12-year catalogFermi/LAT spectrum using a log-parabola can explain the data up to ~ 3 GeV.Above ~ 3 GeV, a power-law excess is present, which has been previouslyreported in LAT/H.E.S.S. analysis. However, including a corona spectralcomponent can also describe the data well. In this scenario, the hardX-rays/soft gamma-rays are due the corona and the MeV to GeV emission is due tothe jet.

Centaurus A: Exploring the Nature of the Hard X-ray/Soft Gamma-ray Emission with INTEGRAL