Questions tagged [spectroscopy]
Questions about the measurement of light waves whereby the wavelength is classified by its position in the electromagnetic spectrum.
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Why do linear velocity redshifts correspond to linear pixel shifts when the spectra are binned in constant log wavelength?
In Tonry & Davis (1979), they describe spectroscopic redshift measurement via correlating with templates at known redshift. In Section IIIa, they say "Because the spectra are binned linearly with ...
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How can ionized emission line flux decrease as a function of increasing metallicity or abundance?
The chemical evolution of galaxies is an important way to learn about their formation and stellar/gaseous constituents. Many galaxies show narrow emission lines at optical wavelengths (3500-9000 ...
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Infrared Astronomy for non transiting objects?
I understand how infrared spectroscopy works for determining molecules in the atmosphere of a transiting object (like Venus from Earth). But how does this work for objects that don't pass between us ...
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Can visible wavelength spectroscopy study an exoplanet's chemical composition directly?
I know spectroscopy of light in visible wavelengths is very effective for studying and determining the chemical composition of bodies within the solar system and bright objects outside of it. However, ...
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Bright lines in a continuum spectrum
Dark lines in a continuum spectrum is common. But are there bright lines too?
By the stimulated emission process, the light can also be amplified, right?
In this case, we should get bright lines ...
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How do you estimate the error on the height/width of a Gaussian?
I'm trying to fit Gaussians to several lines in a spectrum that I have. Some of them overlap with one another, causing the fitting program that I'm using to not be able to give reasonable estimates ...
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What is an "arc" spectrum ?
I sometimes hear about astronomers using an arc spectrum to calibrate observations. For example a "He-Ar arc spectrum". What is an "arc" in this context? I assume it's nothing got to do with angles (...
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Why do spectroscopic binaries have approximate circular orbits?
So for an assignment I have to answer the question what I can conclude concerning the shape of the orbit, knowing that it is both an eclipsing and spectroscopic binary.
Now, I think the answer I ...
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How can I determine line luminosities from equivalent width measurements?
I have a set of equivalent width measurements for different emission lines. How can I use them in order to determine the corresponding line luminosities?
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How to use spectral profiles to determine luminosity class?
I know the luminosity classes are: Ia-0 ( Hypergiants ), Ia ( bright supergiants ), ... , VII ( white dwarf ).
I also have learned that you can use the presence of absorption lines ( ie. use spectral ...
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How to determine atomic number density of an element in a star based on equivalent width measurements
Given an equivalent width measurement $W$ of a spectral line of element $X$ and the effective temperature $T_{eff}$ of a star, how can you determine the atomic number density of $X$ in that star?
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user5341
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Gaia: What is the difference between CCDs used for astrometry, photometry, and spectroscopy?
My knowledge of CCDs is that these are sensors which collect photoelectrons. That's about it.
What is a difference between CCDs used for astrometry, spectroscopy, and photometry? As an example, each ...
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Is any consensus forming on the solution to the "Lithium Problem"?
The "Lithium Problem" relates to the fact very-low-metallicity stars appear to have a Li/H ratio approximately one third of what would be expected. The ratio should be the same as the prediction from ...
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How to specify SM libraries for MOOG
I am running MOOG on OS X Yosemite and with $MOOG running the abfind driver I can force fit elemental abundances with an appropriate input line list and model ...
user5341
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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 ...
user5341