Unanswered Questions
84 questions with no upvoted or accepted answers
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Is there any open data base for raw spectroscopy data?
I'm msc. student in physics and will start my thesis in a month. We are in search of a topic with my thesis professor and we talked about many ideas. After all, "what will this give us ...
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Different types of line broadening in stellar and galactic spectra
When analyzing stellar and galactic spectra with spectrographs, the spectral lines get broadened from the instrument. Why do the spectral lines get broadened after the light moves through the ...
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Calculate the uncertainty in measured flux density from an integrated intensity map
I have some ALMA data, in the form of a spectral cube, which I have integrated along the velocity axis to create an integrated intensity ('moment 0') map.
The integrated intensity map shows emission ...
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General questions about SDSS
I'm considering doing research on SDSS spectral classification (STAR, GALAXY, QSO) with machine learning for my school dissertation. Not sure if this is an appropriate place for these kinds of ...
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starting from SSP spectra to evaluate galaxy spectrum and observed mag
I know that the galaxy spectrum, namely the flux per unit wavelength versus the wavelength, is the sum of the Simple Stellar Population (SSP) spectra at a fixed redshift (e.g. similar to eq. 1 in ...
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Would Atlas Pro's prediction about the color of plant in Kepler-186F work as a biosignature to search for life?
The Atlas Pro video that prompted this question is this.
Tl;dr: it is argued that due to the different spectrum of radiation emitted by Kepler-186 and what is known about the evolution of ...
- 4,800
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Cosmic variance - Fourier Transform - a few precisions
I have posted initially on physics exchange but none answer, so I try my chance here (I am going to delete the physics exchange one) :
I cite an original report of a colleague :
If we are interested ...
CommunityBot
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Logarithmic rebinning and continuum removal of stellar spectra
I am trying to learn how to derive the line of sight velocity distributions from galaxy spectrum to extract kinematical parameters like rotational velocity and velocity dispersion. Therefore I need to ...
- 30.7k
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Is threre a relation between relative or absolute error and standard deviation for ratio of power spectra?
I have to compute the variance on this ratio, that is to say on the observable $O$ :
$$O=\left(\frac{C_{\ell, \mathrm{gal}, \mathrm{sp}}^{\prime}}{C_{\ell, \mathrm{gal}, \mathrm{ph}}^{\prime}}\right)=\...
CommunityBot
- 1
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How to remove radial velocity effects of an exoplanet from the host star spectra?
I have a spectra of an M dwarf and I would like to remove the Doppler shift effects due to a known exoplanet, with known planetary parameters, from the whole spectra of the star. I have shifted/...
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What happens to the Fourier Transform of the Measured Spectrum?
What happens when you double the width of the entrance slit of a spectrograph, in turn letting in twice as much light, would there be an improvement in the Fourier transform of the measured spectral ...
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How to algorithmically distinguish between different types of nebulae?
I remember that there are five types of nebulae:
Planetary nebulae have not much to do with planets, but are emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red ...
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Line Flux Ratios in Active galaxies
Good day to everyone.
I wanted to know what is the importance of estimation of line flux ratios in active galaxies? What does it help in characterizing?
As in Lyman $\alpha /$Carbon IV, or Mg II$/$...
- 409
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What is the gravitational wave spectrum of an ellipsoid neutron star like?
If the star is ellipsoid instead a sphere, the wave should be rich of harmonics, not only (2*orbital frequency). Can these harmonics behave the same way, i.e. they appear/disappear together and drift (...
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Is there any synthetic spectrum software for neutron star?
Is there any software that can calculate the emergent spectrum of a neutron star photosphere, for Teff is about 1e7K, density is above 1e21-1e22 cm^-3 ? Output line wavelength is about 0-100A is ...
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