Two Supermassive Black Holes in the Same Galaxy

Profile of the Galaxy – NGC 6240

- Discovered by NASA’s Chandra X-ray Observatory

- Nucleus of the galaxy is extraordinarily bright

- 400 millions Light Year from Earth

-Two black holes in the central region of the galaxy

they are 3000 Light Year apart

They are orbiting each other

Actively accreting material from their surroundings

- Example of massive galaxy

Formation of the Galaxy

- Recent collisions

- Consequences of merging of two smaller galaxies

(Movies of merging of two galaxies)

Optical

-Arcs are result of collision of two galaxies in the past

X-ray

- Detect two supermassive black holes

Observations- Chandra can distinguish two nucleus by measuring details of X-radiation from each nucleus

1. High energy X-ray emission (blue) 2. Low energy X-ray emission (red)

- Optical: central part is not visible in optical wavelength band (due to large amount of dust and gas in such galaxy) - X-ray: better because it is more penetrating to view the centre

Predictions

- The two black holes will merge several hundred years later (this will be the first time we see binary black hole in action)

Create even larger black hole

Release intense radiation and gravitational waves

gravitational waves spread through the universe

LISA (Laser Interferometer Space Antenna) planned by NASA and ESA, will search this waves

(movies of merging of two black holes)

Importance

The observation of two black holes in the same galaxies:

- shows black hole can grow enormous masses in the centre of galaxies by merging with other black hole

- understand how galaxies form and evolve

http://www.mpe.mpg.de/pr20021119.html#movies

Source

Date: 17/12/02

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