Light bending and X-ray echoes from behind a supermassive black hole

Area of Science:

• Astrophysics
• General Relativity
• Black Hole Physics

Background:

• Accretion disks around black holes are irradiated by X-rays from a compact corona.
• X-ray reflection and reverberation provide insights into the environment near the event horizon.
• I Zwicky 1 (I Zw 1) is a narrow-line Seyfert 1 galaxy with a previously studied two-component corona.

Purpose of the Study:

• To observe and analyze X-ray flares from the supermassive black hole in I Zw 1.
• To investigate the origin and behavior of these flares.
• To confirm predictions of general relativity through gravitational lensing effects.

Main Methods:

• Observations of X-ray flares emitted from the vicinity of the supermassive black hole in I Zw 1.
• Detection of X-ray reflection via a relativistically broadened iron K line and Compton hump.
• Analysis of photon energy shifts to determine origins on the accretion disk.

Main Results:

• Observed short flashes of X-ray photons consistent with emission re-emerging from behind the black hole.
• Detected photons reverberating off the far side of the accretion disk.
• Identified energy shifts indicating photons bent and magnified by the black hole's gravity.

Conclusions:

• The observed bent photons confirm a key prediction of general relativity.
• The study provides observational evidence of gravitational lensing by a black hole.
• These findings offer a unique view of the extreme environment just outside the event horizon.