short wave is it better?

[sasup (Stacey)]

I have been reading and first let me say this is a dangerous thing.

OK my question is why is it we relay on visual light to see deep space objects, when instead we could be gathering ultraviolet light, then reformatting as a 2 dimensional representation, on a LCD screen. I ask because it would seem that this would help with the light pollution and seeing issues here in Sydney; I'm not sure i am interpreting the information correctly but it seems that high band energy is less effected by atmospheric disturbances with the exemption of water particles and black energy or radiation. This is the formula as i understand it "The diameter of an image under seeing limited conditions goes as x - 1/5". In addition, adaptive optics correction becomes much simpler and much more effective as the wavelength increases. Is this true?????

Down side:
Of course, there are also substantial difficulties to be overcome when working in the infrared. To begin with, the atmosphere is opaque except for a few wavelength bands or ``windows''. Strong, saturated absorption lines of molecules such as water, carbon dioxide and ozone are present at intervals across the spectrum, leaving many wavelength regions unobservable from the ground. Secondly, the sky is raining photons. Beyond about 2.2 microns, anything at room temperature and above is emitting copious amounts of black-body radiation. For the infrared astronomer it is as if the telescope were brightly illuminated and the sky itself glowing. Not only does the flood of photons create a high background-limited noise floor, but the sheer number of photons (up to 1010 per second per pixel) presents a significant technological challenge. Finally, and partly as a result of the last two considerations, the technology needed to work effectively in the infrared has lagged that of the optical region by a decade or more. (data taken from ITNF). Would this not seem that maybe here in Australia we could utilises this band due to our dry climate? also I have looked at the VRI concepts and cant fallow.

Maybe this should be posed in the beginners area but it just seems odd and strangely archaic that we still use mirrors as a standard.

cheers stacey

[citivolus (Ric)]

This is what you would be looking through in IR:

http://www.jma.go.jp/en/gms/large.ht...ent=2&mode=UTC

Yes, sometimes you get a dry spot passing over, which would allow you to observe strong IR emitters such as star forming regions in molecular clouds. Other times the image would be mud.

I have an IR modified DSLR, btw. It is limited to 700-950nm or so, as that is as high as the sensor can reach. I should do a wide angle milky way shot some time to see just what kind of problems we'd be dealing with by hooking it up to a telescope. A friend of mine back in Canada is working on IR sensor technology as part of his doctorate, so yes, the research, while lagging optical, is being done.

Regards,
Eric

Edit: On re-reading I see you were mentioning ultraviolet as well. This would limit you to observing more energetic objects, as these wavelengths are very heavily absorbed by the atmosphere.

[sasup (Stacey)]

Ah I see so foiled by the water vapour. I'll have to find some other sources materials for further reading, it has me riveted.
PS I just saw that sorry ment to say I.R not ultra. Thanks


cheers Stacey