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 report the discovery of large amplitude X-ray variability in the lowluminosity AGN (LLAGN) MGC 7589, and present possible observational evidencefor accretion mode transition in this source. Long-term X-ray flux variationsby a factor of more than 50 are found using X-ray data obtained by Swift/XRTand XMM-Newton over 17 years. Results of long-term monitoring data in the UV,optical and infrared bands over ~20 years are also presented. The Eddingtonratio increased from $10^{-3}$ to $\sim0.13$, suggesting a transition of theaccretion flow from an ADAF to a standard thin accretion disc. Further evidencesupporting the thin disc in the high luminosity state is found by the detectionof a significant soft X-ray component in the X-ray spectrum. The temperature ofthis component ($\sim19^{+15}_{-7}$eV, fitted with a blackbody model) is inagreement with the predicted temperature of the inner region for a thin discaround a black hole (BH) with mass of $\sim10^{7}\,M_{\mathrm{Sun}}$. Theseresults may indicate that NGC 7589 had experienced accretion mode transitionover a timescale of a few years, suggesting the idea that similar accretionprocesses are at work for massive black hole and black hole X-ray binaries.

The Large Amplitude X-ray Variability in NGC 7589: Possible Evidence for Accretion Mode Transition