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 study the effects of the bulk motion of X-ray flares on the shape andequivalent width of the iron Kalpha line from an untruncated cold disk around aKerr black hole using fully relativistic calculations. The flares are locatedabove a cold accretion disk -- either on or off the rotation axis. For on- oroff-axis flares, the upward/outward bulk motion causes a reduction of the ironKalpha line width. To a distant observer with a low inclination angle (\theta_o\simlt 30deg.), larger upward/outward bulk velocities decrease the extension ofthe red wing, with little change in the location of the blue `edge'. Incontrast, an observer at a large inclination angle (e.g. \theta_o=60deg.) seesboth the red wing and the blue `edge' change with the bulk velocity. Theequivalent width of the iron Kalpha line decreases rapidly with increasing bulkvelocity of flares. However, the `narrower' line profiles observed in someobjects (e.g. IC4329A and NGC4593) are difficult to produce using theout-flowing magnetic flare model with an appropriate equivalent width unlessthe X-ray emission is concentrated in an outer region with a radius of severaltens of r_g=GM/c^2 or more. An important result is that the iron Kalpha lineintensity is found to be constant even though the continuum flux variessignificantly, which is true for out-flowing magnetic flares with differentbulk velocities but similar intrinsic luminosities when located close to thecentral black hole. We find that fluctuations in the bulk velocities ofout-flowing low-height flares located at the inner region (r\simlt 15r_g) canaccount for a constant iron Kalpha line and significant continuum variation asobservered in MCG-6-30-15 and NGC5548. (Abridged)Comment: 30 pages (including 8 figures); minor changes, to appear in ApJ, Nov.  10, 200

The Effects of Relativistic Bulk Motion of X‐Ray Flares in the Corona on the Iron Kα Line in Seyfert 1 Galaxies