MERGING OF THE BLACK HOLES

---

When a sufficiently large mass is concentrated into a small enough volume it collapses into black hole -  the object with extremely small volume and enormous density. The gravitational force around such black hole is so strong, that even the light can not escape it. Until recently, it was thought that giant black holes coalesced in the early stages of galactic formation. Since the discovery of mid-sized black holes, those intermediate in size between small and large black holes, this idea is now being questioned. A newly confirmed mid-sized black hole was found in a galaxy called M82, and is thought to have a mass between 500 and 80,000 times the mass of our sun. The existence of mid-sized black holes suggests that black holes can continue to grow with time, perhaps through black hole mergers, or by 'swallowing' the gas and dust that surround it.  These mid-sized objects may be first-generation black holes that are on their way to becoming the super-massive black holes at the cores of galaxies. The weight of such black holes can exceed weight of the sun in billions times. Black hole mergers emit no light, radio waves, or X-rays, but we can detect them by catching their gravitational waves, which are very intensive during the merging. Animation shows two black holes orbiting around each other in decaying orbits, resulting in a merger.  Then black hole continue the growth drawing the dust and gas in the zone of darkness.

References:

• Black Holes FAQ
• Analytical event horizons of merging black holes
• The merging of two black holes
• Black Hole Spiral-In