Unanswered Questions
132 questions with no upvoted or accepted answers
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Crop a FITS file in shape of another
I have a FITS file, let us say file A. I have another FITS file, file B. File B has a smaller footprint than file A. I want to crop file A in shape of file B. How do I go about doing that?
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calculating mass of galaxy from luminosity
A very elementary question, just to make sure I got this thing right.
Suppose we are given that the mass to luminosity ratio of a galaxy is $2 \frac{M_{\odot}}{L_{\odot}}$.
Let us say, that the ...
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What are the primary astrophysical implications of a proposed mass of about 11 M⊙ for the SN 2023ixf progenitor?
The abstract of the arXiv preprint SN 2023ixf in Messier 101: A Variable Red Supergiant as the Progenitor Candidate to a Type II Supernova (itself recently "discovered" in the observatory) ...
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Trying to understand how to properly implement this equation to a healpix map
So i am working on reproducing a paper (Secrest, N. J., von Hausegger, S., Rameez, M., Mohayaee, R., Sarkar, S., & Colin, J. (2021). A test of the cosmological principle with quasars. The ...
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What is the force that drives electrons along the magnetic filaments of galaxies?
"Milky Way's mysterious filaments have 'older, distant cousins'" https://www.techexplorist.com/milky-ways-mysterious-filaments-older-distant-cousins/54966/?amp=1
Quote from article:
"...
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Convert from magnetic coordinates to true coordinates
I am working with the IGRF (International Geomagnetic Reference Field) model and from a journal article found here, I am able to compute the earth's magnetic field at any point in spherical ...
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How much would you weigh at the equator of the fastest spinning pulsar?
Assuming you have a mass of 70 kg, what would your weight be on the equator of PSR J1748−2446ad?
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What is sonic transition of an astrophysical fluid?
My notes mention sonic transition of a fluid. Is it where the speed of the fluid elements cross the speed of sound in the medium they are located?
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Where can I find galaxy spectra (in the form of FITS files)?
I know there's SDSS and I tried searching for the spectra through the navigate and explore tool under CAS as well as by using RA/Dec coordinates under SAS, but every single time it comes out with 0 ...
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Setting specific CENTER coordinates coordinate in SWARP
The SWARP Documentation specifies that we first set the CENTER_TYPE to MANUAL and then in the CENTER parameter we specify either one of the equatorial coordinates (RA, Dec). This is specified in the ...
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What was the energy/wavelength/frequency of the CMB when first emitted/released?
Given the z redshift of 1089, and the temperature difference between then and now of about 1089, I tried scaling the ev, freq. and wavelength by 1089....
Is that right?
I get a freq. of about 240 ...
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Answer this or don't downvote
Otherwise you'll be showing your complete ignorance in the matter and contempt for the truth.
If the scale factor as a function of time represents or is equal to the average distance between the ...