Black Holes Have Our Galaxy Surrounded

Black holes behaving badly are the subject of a couple of recent studies by two unrelated groups of astronomers. A two person European team discovered a hard X-ray flare in the normally mild-mannered galaxy NGC 4845. After some investigation, they cheerfully concluded that a lurking black hole had pulled in and destroyed an object some 14 to 30 times the size of the planet Jupiter.

In case you don’t think that’s disquieting enough, consider that the planet Jupiter is itself large enough to hold over 1,300 planet earths inside of it.

We wouldn’t even make a good appetizer for that black hole. At best, we’d be the after-dinner mint.

Another two person team, this time from the University of California, Santa Cruz, recently published a sneak preview of a paper that they’ve submitted to the Astrophysical Journal. In that paper, they reveal the results of simulations that they ran based on current theory about how our Milky Way galaxy formed by merging with smaller galaxies.

For an example of the size of the forces thought to be involved, check out the top photograph of two interacting galaxies NGC 2207 and IC 2163, which was taken with the help of the Hubble space telescope. Wowsers.

UC Santa Cruz’s Valery Rashkov and Piero Madau noted that colliding black holes are going to kick up some heavy gravitational waves, which in turn will knock some so-called outcast black holes right out of the Milky Way.

By their calculations, as few as 70 — or as many as 2,000 — of those bitter, brooding black hole outcasts could have our galaxy surrounded right this very minute.

I vote that it’s 2,000. Not that I have any real insider information but just because it sounds cooler and because of that other study released last month which suggested that black holes are easier to form than we thought.

Here’s a suggestive photo put together by a large international team that includes NASA, the European Space Agency, the Chandra Deep Field South, and more. It shows an X-ray image of heated material falling into a black hole. Now I’m not saying that some of those falling objects look a lot like entire galaxies but then again…Does that look safe to you?

How do you feel about knowing you’re completely surrounded by deeply embittered black holes?

[X-ray image credit: NASA, ESA, A. M. Koekemoer (STScI), M. Dickinson (NOAO) and The GOODS Team]

[colliding galaxies image credit: NASA, ESA, and The Hubble Heritage Team (STScI)]