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Amazing New X-Ray Image of the Whirlpool Galaxy Shows it is Dotted with Black Holes

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In any galaxy there are hundreds of X-ray binaries: systems consisting of a black hole capturing and heating material from a relatively low-mass orbiting companion star. But high-mass X-ray binaries — systems consisting of a black hole and an extremely high-mass companion star — are hard to come by. In the Milky Way there’s only one: Cygnus X-1. But 30 million light-years away in the Whirlpool galaxy, M51, there are a full 10 high-mass X-ray binaries.

Whoa. Beautiful! What makes it deep purple?

Where is Oce when you need him?

It has gas,  "In this image, there’s a very strong correlation between the fuzzy purple stuff, which is hot gas in the X-ray, and the fuzzy red stuff, which is hydrogen gas in the optical,” said Kilgard. “Both of these are tracing the star formation very actively. You can see it really enhanced in the northern arm that approaches the companion galaxy.”

Well, that's wonderful. X-rays really do create beautiful images.

He was defending the weak and the oppressed. (No in fact he was feeling weak and oppressed by the jury of its oral exam.)

Sooo, we have to be very careful when interpreting the colors of astrophysics images because they are often not taken in visible light. Visible light is that little part of the electromagnetic field our eyes can see.  And what we call color, is actually how the human eyes+brain perceive the variation of frequency (or wavelenght,  frequency * wavelenght = constant = light speed ).Here is the rest:


You can see that the X-rays are pretty far (and energetic if you follow the arrow), that's light we can't see with our eyes. Hence we don't really have predefined colors for this. Thus, what the astrophysists have to do is to define their own color scale to visualize easier the structures on their images.

So to the question "What makes it deep purple?", the answer is, because that's the color scale they chose. Huehuehue

Here it's even funnier because it's not only one picture, it's the composition of Whirlpool galaxy observed in visible light ("human colors"), and UV represented in purple.

Depending on what kind they are, celestial bodies don't emit in the same spectral bands. It's linked with how energetic are the reactions that produce their light. More energetic means going more towards the Ultra-Violet part of the spectrum and less energetic means going more towards the Infra-Red part.

Thus looking into various spectral bands allow us to see celestial bodies with different energies (that gives clues about what kind of object they are). We can try to analyse if they are spatially organised in some particular shape like a spiral (galaxy) for example; see if this organisation is the same or not in the different wavelenght (it's not : ) ).

Here they wanted to see the clestial bodies called "X-Ray binaries": a black hole eating its poor companion star, and this is super energetic, hence the emission of X-Rays. But the goal was also to see where those monsters are hiding themselves compared with the rest of the galaxy components, we can't see most of them in X-Rays, so we combine another picture of this galaxy taken in visible light where we can see most stars.

(if we see in that spectral brand it's because we are adapted to our Sun light)whirlpool galaxy x ray gif Imgur

Last thing: the spiral arms we see is not where the matter only is, there's matter also between them. These arms show the front of the spiral pressure wave that compresses the gas and creates new stars from which we can see the light.

What was the question already?

I'm not sure but I'm mesmerized by your gif!

Made from the source of the article:


I second that. Amazing, Oce!

Thank you, Oce!!!  

This IS amazing!  

The Whilpool galaxy is thought to have so many X-ray binaries because it’s in the process of colliding with a smaller companion galaxy. This interaction triggers waves of star formation, creating new stars at a rate seven times faster than the Milky Way and supernova deaths at a rate 10-100 times faster. The more-massive stars simply race through their evolution in a few million years and collapse to form neutron stars or black holes quickly.


“We’re catching them at a short window in their evolutionary cycle,” said Kilgard. “The massive star that formed the black hole has died, and the massive star that is accreting material onto the black hole has not yet died. The window at which these objects are X-ray bright is really short. It’s maybe only tens of thousands of years.”

It's funny to think of tens of thousands of years as a short window.

Since it's long compared with the span of humanity.

But brief in star years.

Relatively, humans are less significant than those flies with a life cycle of one day!  We are space specks!

Do you think we have a chance of lasting longer than flies?

It sure does make my problems not seem worth much of anything.

space specks with problems! what problems? what is anything compared to stars and black holes?

Anything is nothing compared with stars and black holes. You're totally right about that, Emily.

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