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NASA releases first Chandra photos
Gedanken writes "Nasa has released the first images from the new Chandra Project X-Ray telescope and they are spectacular. It will be researching high energy events such as supernovas, quasars and black holes. "
I don't think they actually map a part of the X-ray spectrum to the visible spectrum. It would be very hard to do that, and I don't think it's very useful.
All non-visible-wavelength astrophysical images I've seen so far just are intensity-maps at one particular wavelength[1] (in this case in the X-ray spectrum). The intensity of the light at this wavelength is than mapped to a color-map in which black is no intensity, and white is full intensity. In between black and white one can choose arbitrary colors (like red or blue as in the sample images).
[1] Actually, the photons are 'selected' based on their energies. Only photons having an energy between 'this' and 'that' much are measured. And because (Energy) = (Planck's constant) * (Speed of light) / (Wavelength), this procedure automatically measures only those photons that are within a certain wavelength-range.
No its not useless as a piece of evidence. Linear colour maps aren't appropriate for all purposes. In this particular case the colour map was chosen to highlight features of interest to astrophysicists.
Non linear colour maps are all over the place. They're much more common than linear maps. Go buy some Fuji Velvia for your 35 mm camera. It takes awfully nice portraits doesn't it? It's because the colour map is tweaked to provide pleasing flesh tones.
This isn't any different than a mathemetician using a logarithmic scale to do a plot of a function with exponential growth.
It is still around. When it was on its "College Tour" it came to Oneonta, NY... My home town. Oddly, they started the tour here... Anyway, they sound like they are going to be doing other stuff. I think they are trying to get a distributor to get the film on tape though...
their www site is: http://cataland.com
Large print giveth, and the small print taketh away
Those bastards at NASA really just don't care about the health of Supernovas. The last I heard was that repeated exposure to X-Rays is harmful and should be avoided. How dare they! It's time someone made a stand for the health of the cosmos.
You could read a newspaper from half a mile away or see the letters of a stop sign from 12 miles. That's the kind of strength and accuracy packed into the world's most powerful X-ray telescope -- NASA's Chandra X-ray Observatory.
Wow.. works in Xray too.. reminds me of that video camera that could see thru clothing (kinda)..
"Now, the new NudieCam! Using fabulous X-ray technology developed by NASA, you can video tape women in their undies, from up to 12 miles away!"
hah!
---
- Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.
Ok, just what do they look like, then??
Admit nothing, deny everything and make counter-accusations.
Oh My God... they slashdotted NASA. YOU BASTARDS!
I can see the fnords!
...if they just made those pictures with the GIMP.
Rich
X-rays aren't visible to human eyes at all, so of course you have to process the image to display them in visible wavelengths. This is standard practice for all astronomy outside of visible light (which is most astronomy these days, actually.) The image of Cas A was mapped onto a red scale, where
white = highest intensityyellow = high intensity
red = low intensity
black = lowest or no intensity
The quasar image was done similarly, only using a blue scale rather than red. Right now, these colors are pretty much arbitrary, but later on, we'll probably start coming up with color maps that have a bit more science behind them, especially once we get into spectroscopic imaging.
Trust me, you don't want us to start displaying the images in "true-color" X-ray unless you have some passing desire to fry your eyes. Oops. ;-)
- Marshall
mperrin@cfa.harvard.edu
Are any of the images large enough to set as a background (without major stretching)? I haven't looked at many of them (due to the slow server), but the few that I saw seemed too small for such purposes... -ElJefe
Remember, the site is mirrored at both chandra.nasa.gov and chandra.harvard.edu, although both are being slow right now...
*grin* So all of us here at the CfA packed into our main auditorium to watch the press conference via NASA TV (Chandra is being run from here in Cambridge, but the press conference was down at NASA HQ in DC.) As we were walking out of the auditorium around 2, after the conference ended with a display of the two URLs, I overheard one of the astronomers up ahead of me mutter under his breath "OK, now we're gonna get slashdotted." And indeed, by the time I got back to my office, the chandra server was already being reaaaal sloooooow. AFAIK, it's a pretty hefty Sun, but I guess not quite hefty enough.
Luckily, there are other servers which have all the actual data on them for people to do work with. Unluckily, those are all internal-only right now, so y'all are going to have to wait a bit.
The outer wave may be related to an awesome sonic boom resulting from this collision.
Funny.. I never knew there was an atmosphere in space =P
Jeeze... And I thought it was named after Jay Chandrasekhar the director of "Puddle Cruiser", a humerous College movie... What do I know?
Jay Chandrasekhar
http://us.imdb.com/Name?Chandrasekhar,+Jay
Puddle Cruiser
http://us.imdb.com/Title?0144557
Large print giveth, and the small print taketh away
A nebula is an atmosphere-like medium... not anywhere near as dense as earth's atmosphere but plenty thick enough to support sonic booms if you're moving fast enough.
well, seriously tho' that was an awesome picture. specially that 'sploding star. very-very cool. definitely worth the tax payer money. Good job NASA!
They're definitely doing some Photoshop work on thes. X-rays don't look like fire, last time I checked.
These are obviously just touched-up photos of psychics' heads exploding in a dark room, taken at one of NASA's cocaine mines on Jupiter. Seriously, cool pics. I suppose I'll have to bookmark the site and scan it along with Hubble's each week.
Fuji Velvia has incredibly high saturation and fine grain. It is the landscape chrome of choice. However, it butchers skin, which is its major shortcoming.
Fuji makes some nice portrait films, mainly NPH.
Yes and no. The image is of the x-ray portion
of the spectrum, but the colours in the image
that you see merely represent the luminosity
(or number of photons) recieved in each detector
pixel. The colours chosen are arbitrary. It is
customary to use shades of red for x-ray images,
as opposed to shades of grey for optical images.
It certainly makes them prettier too!
Ale
While trying to get to the press kit anyway...
Good judgement comes from experience, and experience comes from bad judgement.
- W. Wriston, former Citibank CEO
So, just so I'm clear, these images are the x-ray part of the spectrum mapped onto the visible spectrum, right? How do they select this mapping? To make the image pretty? Or is that just coincidence?
We should make a Beowulf cluster of those babies. That would ROCK!
/* Just kidding. */
Save the whales. Feed the hungry. Free the mallocs.
always a worthy cause. sorry, I'm biased ;)