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

We present the results from a study of the X-ray variability and the near-IRto X-ray spectral energy distribution of four low-luminosity, Seyfert 1galaxies. We compared their variability amplitude and broad band spectrum withthose of more luminous AGN in order to investigate whether accretion inlow-luminosity AGN operates as in their luminous counterparts. We used archivalXMM-Newton and, in two cases, ASCA data to estimate their X-ray variabilityamplitude and determine their X-ray spectral shape and luminosity. We also usedarchival HST data to measure their optical nuclear luminosity, and near-IRmeasurements from the literature, in order to construct their near-IR to X-rayspectra. The X-ray variability amplitude of the four Seyferts is what one wouldexpect, given their black hole masses. Their near-IR to X-ray spectrum has thesame shape as the spectrum of quasars which are 10^2-10^5 times more luminous.The objects in our sample are optically classified as Seyfert 1-1.5. Thisimplies that they host a relatively unobscured AGN-like nucleus. They are alsoof low luminosity and accrete at a low rate. They are therefore good candidatesto detect radiation from an inefficient accretion process. However, our resultssuggest that they are similar to AGN which are 10^2-10^5 times more luminous.The combination of a "radiative efficient accretion disc plus an X-rayproducing hot corona" may persist at low accretion rates as well.

The X-ray variability and the near-IR to X-ray spectral energy distribution of four low luminosity Seyfert 1 galaxies