NASA Satellite Sees Black Hole Belching Out Hundred-Million-Degree X-rays

The Bad Astronomer writes "NASA's NuSTAR satellite, designed to detect cosmic X-rays, detected a flare of high-energy emission coming from the Milky Way galaxy's central supermassive black hole. The X-rays were the dying gasp of a small gas cloud being torn apart, heated to a hundred million degrees, and then falling into the black hole itself. Events like this are relatively uncommon, so it's fortunate NuSTAR happened to be observing the black hole when it flared."

Comments

If you see a black hole

[Anonymous Coward]

Isn't it already too late?

Re:If you see a black hole

[Jeng]

Would it even be possible to see in the first place though.

Not as in detecting that it exists, but photons are only going one way, and that is the same direction you are going.

Re:If you see a black hole

[Anonymous Coward]

Wrong. Hawking radiation.

Re:If you see a black hole

[ackthpt]

Isn't it already too late?

You'd know it was too late if your spirit was watching your body being irradiated and distorted by the intense magnetic (and other radiation) fields and gravity. You'd be rather amazed while the chap in black, with the scythe rode up on his white horse, Binky and said YOU DON'T SEE THAT EVERY DAY. FIGURATIVELY AND LITERALLY.

Re:If you see a black hole

[93 Escort Wagon]

You should look for a precursor, such as glaciers melting in the dead of night.

Re:If you see a black hole

[Anonymous Coward]

Hawking radiation for a stellar sized or large black hole would look like blackbody radiation from something with the temperature of nanokelvins. Not only would it be very weak, it would be overwhelmed by anything noticeably hotter between you and the black hole, possibly whatever detector you are using to measure the emission. It would be far easier to notice the lack of light from background stars, or even the absence of the 3 K CMB than the light from a black hole with no infalling material.

Re:If you see a black hole

[davester666]

Aw, crap. I live on a glacier.

Re:If you see a black hole

[doccus]

Not to worry.. the event happened several millions of years ago

Burp

[onyxruby]

That's taking belching to a very uncivilized level. Someone ought to teach that black hole some table manners.

Re:Burp

[macraig]

Or teach the table how to lighten up and just hold its breath for a moment until it passes.

HOTHOTHOTHOT

[Anonymous Coward]

Oweee!

Obligatory

[DamageLabs]

Oh shit, the infinite improbability drive is on the fritz again.

Re:Obligatory

[ackthpt]

Oh shit, the infinite improbability drive is on the fritz again.

Someone just tipped the waiter a penny aboard The Bistromath.

Is it a dry heat

[Anonymous Coward]

I would imagine so- but you never know for sure

The title makes me weep for science journalism

[Ziggitz]

X-Rays have no temperature, they are EM radiation, not matter.

Re:The title makes me weep for science journalism

[Anonymous Coward]

Even more so, I expected TFS to say what kind of "degree" TFH (Headline) meant. Metric? Imperial? LOC? But nothing to see here, please move along.

Re:The title makes me weep for science journalism

[Synerg1y]

Yep, sure enough: http://science.howstuffworks.com/x-ray2.htm

Re:The title makes me weep for science journalism

[mark-t]

I suppose it depends how you read the sentence, but I understood that they were talking about the gas being heated to those temperatures, and the x-rays were the accompanying emitted EM radiation as a result, not the x-rays themselves being that temperature.

Re:The title makes me weep for science journalism

[dan_in_dublin]

dont photons have an energy that is inversely proportional to the wavelength (shorter wavelenths = photons at higher energy).. i'm no particle physicist but something emitted the photon which is the particle by which the xrays and all em propagate.. then photons get released when electrons drop to lower energy levels in their atomic orbits.. so as the matter of the cloud compresesd in the effect of the black hole's gravitational pull, the temperature of the matter incresaes, the energy of the electrons increases correspondingly, the electroncs go to higher orbits around the atom and they drop back to lower orbits by releasing photons. so maybe they can measure the temperature of the atom at the point where the electron was released by looking at the wavelength / other properties of the photon ? wasnt the temperature of the big bang measured via the universal background radiation which is the photons released by the matter in the universe about 300,000 years after the big bang (the point at which temperatures had cooled sufficiently for electrons to get into stable orbits around atoms ?

Re:The title makes me weep for science journalism

[Anonymous Coward]

I guess it would be better if we never got the news. Semantics are definitely more important. Where are all the professional journalists who volunteer for Slashdot? Come on guys! We have a semantic epidemic here and need your help. It doesn't pay, but there is demand.

Re:The title makes me weep for science journalism

[NoNonAlphaCharsHere]

That's just the Slashdot headline, not from TFA. So, yeah, no big surprise for facepalm-inducing editing. Meanwhile, TFA gets Extra, Extra, Extra Credit for the "Click to schwarzschildenate" caption.

Re:The title makes me weep for science journalism

[avandesande]

It's very common for astronomers to refer to stars by their temperature.... red stars are cold and blue stars are hot. Betelgeuse for instance is 3500k.

Re:The title makes me weep for science journalism

[Anonymous Coward]

It's a common, but somewhat sloppy, convention in physics to refer a collection of photons whose energies are the same as the Planck distribution for a black-body radiator of temperature T as "T-degree photons".

Whether or not that's reasonable, whether Slashdot titles count as science journalism, whether photons count as matter, and all sorts of other minor points are certainly arguable, but the use of that phrase is hardly the fault of "science journalism".

Re:The title makes me weep for science journalism

[amRadioHed]

At that temperature the scale is fairly irrelevant. It's less than an order of magnitude difference either way.

Re:The title makes me weep for science journalism

[Anonymous Coward]

The color (frequency) of E/M radiation is directly proportional (equivalent to) to the temperature of the material that's transmitting the E/M radiation. The way the title is phrased implies the former is understood. It makes perfect sense to anyone familiar with basic principals of physics.
Of all science journalists Bad Astronomer is one of the best, perhaps at times a bit to 'sciencey' so that the way he phrases things is open to nitpicking.

Re:The title makes me weep for science journalism

[Chris Burke]

X-Rays have no temperature, they are EM radiation, not matter.

I weep for whoever told you a collection of photons can't have a temperature in the same way a collection of particles can. Who was it? Was it... no one?

Black body radiation has a characteristic temperature just like the black body that produced it, however in the case of the photon gas it's the Plank's Law distribution of energy in photons rather than the Maxwellâ"Boltzmann distribution which describes the matter.

If there's any sloppiness in the title at all it's specifying just the X-rays when you'd technically have to include all photon energies to get the correct temperature, just like you would include all the particles in a gas or solid. However I think it's pretty much in the noise as far as inaccuracy goes. Unlike your statement. Sorry.

P.S. Such radiation has a temperature and *also entropy*, which is inversely proportional to temperature. So for example if you assume the earth is more or less in equilibrium with the sun, that means the total energy received is equal to the total energy output, but the temperature of the received radiation is much higher, meaning less energy, meaning the earth is emitting a net-positive amount of entropy. In case you've ever wondered how exactly the whole "the earth is not a closed system; it's powered by the sun" thing worked in terms of entropy.

Re:The title makes me weep for science journalism

[dreamchaser]

X-Rays have no temperature, they are EM radiation, not matter.

I love how people who didn't bother to RTFA get modded insightful. The summary is bad but the article clearly states that the gas creating the X-ray emissions is what is heated.

Re:The title makes me weep for science journalism

[Anonymous Coward]

X-Rays have no temperature, they are EM radiation, not matter.

I had no trouble understanding that this is block-body radiation from the title. It's just like color temperature, but extended to far higher energies.

Re:The title makes me weep for science journalism

[Anonymous Coward]

X-Rays have no temperature, they are EM radiation, not matter.

E=mc2 my friend

Re:The title makes me weep for science journalism

[joe_frisch]

If the X-rays have a spectrum that looks at all like a blackbody then temperature is a reasonable way to describe them. If you have a box of material at some temperature, the inside of that box will be filled with electromagnetic radiation who's spectrum matches that temperature and it is reasonable to describe that radiation as having a temperature (even from a technical thermodynamic point if view). As a very rough guide, you get radiation with photon energies in the range of 1eV for 10,000 degrees Kelvin. So, 100 million kelvin would give photons vaguely in the 10KeV range which are X-rays.

If the X-rays were only over a very narrow range in frequencies, then temperature would not be a good description, but it sounds like these were nearly thermal.

Re:The title makes me weep for science journalism

[dido]

It's clearly a reference to Wien's displacement law. At 100 million kelvins, the peak blackbody emission frequency by the Wien displacement law would be somewhere in the region of 6e18 Hz (0.05 nm), which is well into the hard X ray region, almost energetic enough to be called low-energy gamma rays.

Re:The title makes me weep for science journalism

[Anonymous Coward]

From TFA: "the gas can reach temperatures of hundreds of millions of degrees!

Gas that hot emits X-rays, which is how this flare was seen by NuSTAR"

Re:The title makes me weep for science journalism

[tragedy]

I weep for whoever told you a collection of photons can't have a temperature in the same way a collection of particles can. Who was it? Was it... no one?

It's pefectly reasonable to think that collections of photons don't have a temperature. It's also perfectly reasonable to think that not everything other than hydrogen and helium is a "metal". Some other posters

Re:The title makes me weep for science journalism

[Chris Burke]

Sure, it's reasonable to think that, just incorrect. Happens all the time. Don't confuse unusual nomenclature with aspects of thermodynamic theory that you weren't familiar with. Don't go complaining about a perfectly correct statement because it doesn't match the high school notion of what temperature means.

Re:The title makes me weep for science journalism

[EdgePenguin]

Hows the view from mount stupid?

Others have explained the physics, but yes, talking about the temperature of an EM emission is perfectly acceptable, even common, in physics. You could nitpick and say that any particular X-ray photon does not tell you the temperature of what emitted it, but in order to discuss complex matters you need a shorthand, and one of those is to say that a collection of photons has a temperature (whilst really meaning "this collection of photons is consistent with black body emission at temperature T")

Here is some educational material for you: http://en.wikipedia.org/wiki/Wien's_displacement_law

Re:The title makes me weep for science journalism

[Anonymous Coward]

That wouldn't even be a good nitpick. In the same sense that a single photon wouldn't have a temperature, a single particle wouldn't have a temperature, in the more simplistic definition, either. Thanks to modern statistical mechanics, the definition of temperature has become much broader and well understood, applicable to more than just vibrating or bouncing atoms.

Re:The title makes me weep for science journalism

[Ziggitz]

The energy of a photon at any given frequency is constant. That means that every gamma ray on earth is more energetic than any X-Ray in space. To describe the temperature of a photon is meaningless and gives the false impression that temperature can vary for a given fixed frequency of light. When describing EM Radiation it makes much more sense to consider the energy of the photons in eV or to describe the entire energy amount of a discharge in joules.

The attributing of temperature of light was the author's way of making the article more exciting when it really added no information and gave false impression that a given frequency of light changes it's energy state.

Re:The title makes me weep for science journalism

[Chris Burke]

To describe the temperature of a photon is meaningless

To describe the temperature of a massive particle is meaningless.

Only by having a collection of particles (whether massive or not) that follow a particular statistical distribution can temperature be meaningfully talked about. Those distributions are different for different types of collections of particles. The one that describes ideal gasses is not the only one.

and gives the false impression that temperature can vary for a given fixed frequency of light

I suppose if you assume that X-ray is a single fixed frequency and that they were talking about single photons, but that would be as silly as thinking someone was talking about the temperature of a single particle that had a single specific energy, when obviously they must be talking about all energies of all particles in the collection.

You seem to be treating this like X-Rays are a single, fixed frequency and/or that these observed X-Rays are like a like a laser with a single output frequency.

The X-Ray range is from about 0.001 nm to 10nm. At 100mil K the spectrum is very nearly entirely in that range -- in fact nearly entirely between 10 pm and 200 pm. If you changed the temperature somewhat, the spectrum would change, but would still be in the X-Rays. So yes, temperature can vary and still be in a range of frequencies of light. 100mil K X-Rays and 90mil K X-Rays are different, in that there is a different energy spectrum.

When describing EM Radiation it makes much more sense to consider the energy of the photons in eV or to describe the entire energy amount of a discharge in joules.

.

But the photons cover a range of energies, so it makes no sense to talk about their energy in eV because there isn't just one value, and while you could talk about total emission (in Watts would probably be more interesting), that wouldn't tell you anything about the wavelength distribution.

it really added no information

The description as given is the most correct, and provides the most meaningful information.

Plus it added the chance for you to learn all these things about the concept of temperature!

Re:The title makes me weep for science journalism

[tragedy]

The point I was making is that the definition being used is fairly specialized to the context, just as the definition of "metal" differs from one context to another. Consider how context sensitive mathematical symbols can be. Is it a cross product or a cartesian product or a standard product? Is it a dot product or a logical and? Don't even get me started on the overloading of the greek alphabet. If someone is familiar with a term in one context, confusion is natural when they encounter it in another and it becomes a false cognate. In short, you can educate someone about the meanings of terms in context without needing to be arrogant jerk about it.

Re:The title makes me weep for science journalism

[Chris Burke]

The point I was making is that the definition being used is fairly specialized to the context

There is no context in modern science where "only matter can have temperature" is correct.

In short, you can educate someone about the meanings of terms in context without needing to be arrogant jerk about it.

When the someone is sincerely questioning or just confused, then I make every effort not to be. When the someone is themselves being an arrogant jerk, calling a PhD in astronomy stupid because of their own ignorance, I see no reason to be anything else.

If the subject of this thread was "How can X-Rays have temperature?" or similar then you would have seen that reflected in my post.

But it isn't.

Re:The title makes me weep for science journalism

[tragedy]

There is no context in modern science where "only matter can have temperature" is correct.

Common definitions of temperature typically define it as a property of matter. Given those kinds of definitions being presented, believing that "only matter can have temperature" is perfectly reasonable. Referring to the temperature of electromagnetic radiation is a convention and not everyone is going to be familiar with this convention.

Remember, not all science is physics. Well, ok, everything actually is ultimately physics, but many other sciences don't focus that way. Medical science, for example, mostly deals with temperature just as a property of matter.

When the someone is sincerely questioning or just confused, then I make every effort not to be. When the someone is themselves being an arrogant jerk, calling a PhD in astronomy stupid because of their own ignorance, I see no reason to be anything else.

You do have a point there. Although, I'm not sure it's Phil Plaitt himself who wrote the title that the original poster was referring to. Journalistic titles often need to be taken with a big grain of salt anyway.

Anyway, the Socratic method may be a traditional way of educating people. On the other hand, they ended up making him drink hemlock, so maybe it isn't always so endearing.

P.S. I thought I'd written a bit more in my original post in this thread, but I just looked back in the history and I somehow managed to clip off the end of that post.

Re:The title makes me weep for science journalism

[Anonymous Coward]

Referring to the temperature of electromagnetic radiation is a convention

No... that is not a convention. A group of photons can have temperature as much as any group of particles, both deriving from the same fundamental definitions of temperature. Maybe some freshman physics books would gloss over this, but it is an example in just about every introductory thermal physics and statistical mechanics book I've seen. And it doesn't really matter what field you are talking about, as the definition of temperature is inherently physics short of some other field using the same word as jargon for something else (e.g. astronomy's use of "metal"). Astronomy doesn't have a jargon override for temperature, it is the same as what comes from physics, and if anything cosmology and astrophysics do have cases where they use photon gases as example situations too. Medical science also doesn't deal much with muons, but that doesn't mean medical science has a separate convention that exclude muons ... it just isn't relevant usually. The temperature of photons however is quite relevant to many aspects of astronomy.

Re:The title makes me weep for science journalism

[tragedy]

Maybe some freshman physics books would gloss over this, but it is an example in just about every introductory thermal physics and statistical mechanics book I've seen.

Okay, but those aren't books that a medical doctor or an archaeologist would need to crack open during the course of their educations. For them, temperature is just a physical property of matter, and the temperature of electromagnetic radiation is an abstract concept.

When are we sending astronauts?

[Synerg1y]

Any volunteers?

Re:When are we sending astronauts?

[Anonymous Coward]

Suggest we recruit from the middle east

How does something escape a black hole?

[gameboyhippo]

In order to be detected, something must escape a black hole. Since my understanding is that not even photons could escape a black hole, how does these X-Rays manage to do it?

Re:How does something escape a black hole?

[PaulBu]

It was emitted before, not after cloud was absorbed into the black hole...

My favourite lines from TFA:

So maybe saying this was a belch is a bit misleading, since you do that after you eat something. This is more like your food screaming loudly and incoherently and flailing around while you’re actually eating it. Is that better?

Paul B.

Re:How does something escape a black hole?

[geekoid]

Hawking radiation escapes.

Re:How does something escape a black hole?

[Anonymous Coward]

X-rays _are_ photons, you fruitcake.

Re:How does something escape a black hole?

[NoNonAlphaCharsHere]

This isn't Hawking radiation.

Re:How does something escape a black hole?

[Anonymous Coward]

this also isn't purely theoretical like hawking radiation

Re:How does something escape a black hole?

[harperska]

Not only is TFA not talking about Hawking radiation, Hawking radiation doesn't even technically escape. Hawking radiation particles are actually formerly virtual particles that are generated just outside of the event horizon. Virtual particles are created in particle-antiparticle pairs which then instantly self-annihilate before the universe notices. But when the pair appears just outside of a black hole, sometimes one particle falls into the hole allowing the other to continue existing. This produces the illusion that radiation is coming out of the hole, where none actually is.

Re:How does something escape a black hole?

[dido]

It didn't escape the black hole. These photons were generated as matter was falling into the hole and being compressed by the hole's gravity before passing beyond the event horizon. More like they were never inside the hole to begin with.

Re:How does something escape a black hole?

[darenw]

Very good - this will make astrophysics more appealing to cats!

I hate this

[PopeRatzo]

Naturally. The Bears go to 5 and 1 and look really good to go to the playoffs and here comes a high-energy X-ray cataclysm.

This is how it always goes for me.

Re:I hate this

[Sprouticus]

Desperately need some mod points....

Re:I hate this

[NoNonAlphaCharsHere]

The Bears going to the playoffs has approximately the same odds as a high-energy X-ray cataclysm.

Re:I hate this

[Tablizer]

Hard to bear, eh?

Re:I hate this

[IHateEverybody]

Cowboys fans on the hand are just happy to have something new to blame on Tony Romo....

Version of story not written by shit head for same

[Anonymous Coward]

NASA's NuSTAR Spots Flare From Milky Way's Black Hole
http://www.jpl.nasa.gov/news/news.php?release=2012-333

Hundred-Million Degrees?

[The_Rook]

is that Fahrenheit or Celsius?

Re:Hundred-Million Degrees?

[Pro-feet]

Even more interesting: is that Kelvin or Celcius?

Re:Hundred-Million Degrees?

[Anonymous Coward]

is that Fahrenheit or Celsius?

Most likely Kelvin. Standard International (SI) are appropriate for any physics discussion (Kelvin or Celcius) and astronomical temperatures are typically Kelvin, since computations for frequency and electron-volt equivalents are absolute-zero based.

Re:Hundred-Million Degrees?

[dissy]

First one, then the other.

Re:Hundred-Million Degrees?

[Rogerborg]

Only the Lord Kelvin can preserve you from entropy.

A hundred million degrees ain't so much. The University of Mumbai churns out more than that a year.

Handy dandy chart

[Anonymous Coward]

For 100,000,000 in kelvin:

Celcius: 99,999,727
Fahrenheit: 179,999,540
Rankine: 180,000,000
Delisle: -149,999,627
Newton: 32,999,910
Reaumur: 79,999,781
Romer: 52,499,864
Radians: 1,745,329
Grads: 111,111,111
Snark: 9,001

Upper Limit

[AnotherAnonymousUser]

I've always been curious, but is there an upper limit on energy density for a given space, or an upper ceiling on how hot something can get?

Re:Upper Limit

[Neil Boekend]

Since heat is movement, the upper limit to heat would be when the atoms are moving at C. How hot that is is a bit beyond my physics education to calculate, but matter isn't transparent at that temperature. Atoms do not exist. Neither do protons or neutrons. Everything is a quark-gluon plasma at 4 trillion degrees C. What it is at even hotter temperatures is unknown to me (and a quick Google/wikipedia).

Re:Upper Limit

[EdgePenguin]

Your question is equivalent to "Is there a singularity at the beginning of the universe".

Going back through time in conventional cosmology leads you through increasing temperature and density, until conventionally you reach a point where both are infinite - the singularity. This, however, is merely a mathematical result that fits with observations later in the universe, and our theories about gravity. We have no way of directly knowing if the universe ever was a singularity.

Re:Upper Limit

[Anonymous Coward]

Atoms moving at c would be essentially infinite temperature. Going with one of the simpler definitions of temperature being just average kinetic energy, under relativity that would form a continuum from zero to infinity, since kinetic energy keeps going up as you get closer to c.

too much science-fiction

[KingBenny]

or just too much fantasy has me thinking : so this expanding universe is actually literally slowly going down the drain one galaxy at a time. The big black hole, the ultimate cosmic zipfile. Where information does not get destroyed but compressed by algorithms only the ancient ones understand. So when they finally get back to check on their experiment all they need to do is collect the data about everything that happened over time.
yap, definitely too much fantasy there

Selection Bias?

[hicksw]

Events like this are relatively uncommon, so it's fortunate NuSTAR happened to be observing the black hole when it flared.

And when nobody is looking, nothing happens?

-
-99 pednatic; -999 spilleng; it's the TYPOs