All Questions
11 questions
1
vote
0
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49
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Tiling the sky with astropy-healpix
I have a bunch of files containing sources with galactic l and b values. What I want is to redistribute the sources such that each new file contain sources that fall within 15 degrees of a central l,b ...
2
votes
0
answers
101
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How can I compute reasonable errors on my Gaussian fits to the observed strong optical lines of interest?
I'm fitting Gaussians to optical lines spanning from H-beta to Sulfur using Astropy's Gaussian (https://docs.astropy.org/en/latest/api/astropy.modeling.functional_models.Gaussian1D.html) model with a ...
- 1,111
3
votes
2
answers
152
views
How to construct optimal Wiener Filter?
I am trying to construct a Wiener Filter, to filter the ratio of the peak from the cross-correlation function, between a galaxy spectra and a template spectra, with the peak of the auto-correlation ...
- 849
0
votes
1
answer
161
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2D Galaxy Spectrum taken by long-slit-spectrograph
I have the 2D data (shape(1125,2058) taken by a long slit spectrograph, which looks as follows:
The y-axis corresponds to the distance from the center, where the center is at the most bright green ...
- 849
1
vote
0
answers
64
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How to plot matplotlib plots as tables in python(hdf5 tables)
I have extracted the data from a fits file and plotted a spectra.i need to do the same for multiple fits files .how can I store the resultant spectra's as a hdf5 table or fits table?
And which ...
- 79
2
votes
1
answer
149
views
How to fit LOSVD of a galaxy with gauss hermite parametrization
I have recovered the following LOSVD from an elliptical galaxy, that I now want to fit a gauss-hermite-parametrization to and derive the kinematical parameters rotational velocity, velocity dispersion ...
- 849
3
votes
0
answers
87
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S/N binning of 2D spectral galactic data
I have the 2D spectrum of the ellipical galaxy NGC 4697 taken by a long slit spectrograph. The x-direction (horizontal) corresponds to wavelength and the y-direction (vertical) corresponds to distance ...
- 849
1
vote
1
answer
582
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How to calculate S/N in galaxy absorption spectra?
I want to calculate the S/N of an galaxy absorption spectrum.
I therefore chose a part of the spectrum which contains very little to none absorption features and should be only made up of noise and ...
- 849
5
votes
1
answer
382
views
How to extract galaxy spectra for different radii in Python for spectra taken by long slit spectrograph?
I am trying to extract the kinematics from the elliptical galaxy NGC 4697 using the Fourier Correlation Quotient (FCQ) algorithm described by Bender (http://adsabs.harvard.edu/full/1990A%26A...229.....
- 849
2
votes
0
answers
573
views
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 ...
- 849
2
votes
2
answers
204
views
Technique for folding sparse event data in order to detect an underlying periodicity?
@JamesK's answer to When will the next transit of Earth be visible from Mars? Was the last one really on May 11, 1984? lists dates of 18 transits which I've converted to days since 1500-Jan-01 as
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- 30.7k