Questions about the observed frequency range of the electromagnetic radiation of a celestrial object.

learn more… | top users | synonyms

0
votes
1answer
39 views

Why do we observe spectral lines of specific energy?

The basis of my confusion is that atomic orbitals, even when described accurately by quantum numbers, have definite energies, meaning they represent energy eigenstates of the wave function. They're ...
2
votes
2answers
64 views

about H$_\alpha$ and H$_\beta$ lines in astronomical objects' spectra

Generally there may be some line ratio between the two lines. If H$\alpha$ is strong, it is quite possible we can see H$_\beta$ too. Is it possible we can see H$_\beta$, but can not see H$_\alpha$? ...
1
vote
0answers
27 views

Spectral analysis of AGN (velocity dispersion of galaxy absorption, doppler shifts)

I was wondering what parameters I need to know/measure to calculate the velocity dispersion of a galaxy, specifically an AGN. Also, I have spectra where there are blueshifted and redshifted ...
4
votes
2answers
73 views

Typical wavelength of solar flare

I read that solar flares are customarily viewed in H-alpha light, as a temporary brightening of a small portion of chromosphere. What all can be interpreted from this? Is it because, energy of the ...
1
vote
1answer
23 views

In the chromoscope, what is the X-ray source between Ophiuchus, Libra and Scorpius?

http://www.chromoscope.net/ is a nice toy. Pressing 'L' shows the constellations as guide. There's a bright X-ray source between Ophiuchus, Libra and Scorpius. In Hydrogen-Alpha there are two ...
1
vote
1answer
56 views

What is this graph showing?

This is from the NED What do these three titles mean? log fb (Jy) MRK 1014 Log v (HZ) Why is there LINE,LINE,...
2
votes
1answer
46 views

Invisible in visible light but visible in non-visible light?

This may be a stupid question, but I've been wondering this for a while and haven't yet found a solid answer. I'm worried the answer will be something along the lines of "of course not, you dummy" but ...
2
votes
1answer
54 views

Broadband spectrum of Sun

Broadband spectrum is one which is inclusive of all the observed wavelength ranges. In the case of the BB spectra of our Sun, there is a sharp (non-differentiable) kink in the curve in the UV-range ...
3
votes
2answers
826 views

How to measure distances to stars by means of spectroscopic parallaxes?

How to measure distances to stars by means of spectroscopic parallaxes on practice? What is the accuracy of measuring distances using this method compared with distances based on HIPPARCOS ...
9
votes
3answers
400 views

How to detect emission lines in optical spectra?

Is there any handy module to detect emission lines in a spectrum like one we get from the Sloan Digital Sky Survey (SDSS)? You can see there are many emission lines like Ha,OI in the spectrum below. ...
7
votes
1answer
152 views

What is the Lyman Alpha forest Used For?

The Lyman-alpha forest is an interesting feature found in the spectra of sufficiently distant objects. This series of absorption lines extends over a range of frequencies, and are a result of the ...