"The Awakening" --When Will the Supermassive Engine at the Heart of Our Galaxy Reignite?

 

 

          

 

Astronomers have long wondered why it was that the super-massive black hole in the center of our galaxy was relatively quiet. Known as Sagittarius A*, a massive hole, containing about 4 million times the mass of our Sun. Yet, despite its size, the energy radiated from its surroundings is billions of times weaker than black holes at the core of other galaxies. Our neighboring galaxy, Andromeda, by comparision has a black hole 20 times the size of ours. However, the smaller size of the Milky Way and our distance from the galactic center (25,000 light years) may be a reason for our well-shielded existence. The fact that life exists on Earth, and the fact that we do not live on a planet closer to our galactic core, may not be a coincidence.

"We have wondered why the Milky Way’s black hole appears to be a slumbering giant," observed Tatsuya Inui of Kyoto University in Japan. "But we realize that the black hole was far more active in the past. Perhaps it’s just resting after a major outburst."

Tatsuya Inui was part of a team that used results from Japan’s Suzaku and ASCA X-ray satellites, NASA’sChandra X-ray Observatory, and the European Space Agency’s XMM-Newton X-ray Observatory, to determine the history of our black hole.

It turns out that, approximately 300 years ago, Sagittarius A* let loose, expelling a massive energy flare. Data taken from 1994 to 2005 revealed that clouds of gas near the central black hole, known as Sagittarius B2, brightened and faded quickly in X-ray light. The X-rays were emanating from just outside the black hole, created by the buildup of matter piling up outside the black hole, which subsequently heats up and expels X-rays.

These pulses of X-ray take 300 years to traverse the distance between Sagittarius A* and Sagittarius B2, so that when we witness something happening in the cloud, it is responding to something that happened 300 years ago.

Amazingly for us, in a rare occurrence of perfect cosmic timing, a region in Sagittarius B2, only 10 light-years across varied dramatically in brightness. "By observing how this cloud lit up and faded over 10 years, we could trace back the black hole’s activity 300 years ago," said Katsuji Koyama of Kyoto University.

"The black hole was a million times brighter three centuries ago. It must have unleashed an incredibly powerful flare."

The image at the top of the page shows the central region of our Milky Way Galaxy as seen by Chandra X-ray Observatory. The bright, point-like source at the center of the image was produced by a huge X-ray flare that occurred in the vicinity of the supermassive black hole at the center of our galaxy. Image: NASA/MIT/F. Baganoff et al.

The Daily Galaxy via Kyoto University

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Comments

[ta2025]

WRONG...

"These pulses of X-ray take 300 years to traverse the distance between Sagittarius A* and Sagittarius B2, so that when we witness something happening in the cloud, it is responding to something that happened 300 years ago."

that would be 27,000 + 300 years ago. It would take xrays 27,000 years to reach us from the core.

[Lightsaber Sharpener/Blacksmith]

Reading comprehension should be a prerequisite to commenting on this site. ta2025, unless Earth has been recently renamed Sagittarius A or B2 by the International Astronomical Union, you are the one that is wrong. The 300 years is an observed distance, not in reference to distance from earth. This is pretty clear in the phrase that you yourself quoted.

[James Ph. Kotsybar]

SAGITTARIUS A*
-- James Ph. Kotsybar

Mysteriously cloaked, obscure despite
Interior illuminating glare,
Long veiled by your own dusty lace-curtain,
Kept hidden, locked within your gallery,
You work continuously through the night.

We speculate about what goes on there
And, though still not absolutely certain,
Your close companions that we’ve seen scurry

Give us reason for darkest suspicion
About the nature of your deepest part,
Long overlooked, seething with sedition,
And we believe we’ve glimpsed rapacious art.
X-rays show what other light can’t impart:
Young stars conceal a black hole at your heart.

[Florin]

nice post , have you seen this one ? http://www.youtube.com/watch?v=oURVtGKW420 i recommend

[Thomas Mazanec]

IIRC, M33 (or Triangulum) has no black hole more massive than 1500 suns...is it a better galaxy for life than The Milky Way?

[village idiot]

Another reading comprehension-challenged reader here.
SgrA is 300 LY from SgrB, but they're both roughly 27k LY from us.
Seems to me TA2025 is right. We're seeing effects of SgrA on Sgr B with a 300 years delay, but about 27k + 300 years ago . . . a light "echo" as I believe it's known.

[village idiot]

25k + 300, sorry.

[yas]

"When Will the Supermassive Engine at the Heart of Our Galaxy Reignite?"

Not enough fuel yet near Sagittarius A. Don't worry, it will go berserk soon after abundant amounts of feed come to it.

[justAMook]

I have to agree with ta2025. The event itself, the X-ray pulse at Sagittarius A*, took place 27K (+-1K) years ago, but the light from the event took 300 years to reach Sagittarius B2. I imagine the author of this article really understood and meant that. Just needed to proofread it a bit more critically.

Now, if only the astrophysicists of 1712 had thought to orbit an X-ray observatory. Just think of the pictures!

[lazarlin]

O.K maybe by village idiots reckoning not enough fuel to ignite....but we all need fuel in the morning....what if it decides to yawn?then get it,s act together?
many a true word spoken in jest,,,,