Unanswered Questions
84 questions with no upvoted or accepted answers
3
votes
0
answers
73
views
How to obtain exoplanets transmission spectra from JWST's NIRISS data of WASP96?
I was having a look at JWST's NIRISS data of WASP96 (specifically at the x1dints fits file which should be already calibrated). From this, I would like to obtain a result in a fashion similar to the ...
- 30.7k
3
votes
0
answers
80
views
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
3
votes
0
answers
191
views
Is there a tool to convert N-body RAMSES simulation file formats to GADGET 2 format in Python?
I am looking for a way to convert RAMSES files to GADGET-2 binary files because I want to use the package SimSpin (https://github.com/kateharborne/SimSpin/blob/master/R/make_simspin_file.R) which is ...
- 30.7k
3
votes
0
answers
30
views
How to find x-values of fourier-transformed correlation functions in velocity space?
I am trying to extract the kinematic parameters (rotation velocity, velocity dispersion, ...) of an elliptical galaxy by extracting the kinematical broadening function using the FCQ-Algortihm first ...
- 8,452
3
votes
0
answers
53
views
How to determine the temperature of a star according to the strength of the line in the spectra?
Based on the comments, I have changed some things.
Below is a graph showing the relative strength of $H_\gamma$ and Fe I lines of two stars. Which star is hotter?
This is a question from the book:An ...
- 41
3
votes
0
answers
95
views
How were "microshutters" or other multiplexed or multi-object techniques first used in Astronomical spectroscopy?
This answer to How will microshutter arrays be used in the James Webb and future space telescopes? explains how multiple objects can be selected so that the throughput of a spectrometer can be ...
- 30.7k
3
votes
0
answers
590
views
What is the difference between spectroscopy, spectrography and spectrometry?
Spectroscopy is the study of spectra, spectrography is the writing of the spectra, and spectrometry is the measure of spectra. So from an etymological perspective, there is no real difference between ...
- 17.6k
3
votes
0
answers
468
views
How does the ESPRESSO Echelle spectrograph fold the spectrum so nicely?
The CBC News Technology and Science Q&A This ESPRESSO machine doesn't make coffee but scans the skies for habitable planets includes a nice description of ESPRESSO (Echelle SPectrograph for Rocky ...
- 30.7k
3
votes
0
answers
2k
views
What is meant by ionization states?
I am going through the theory of Saha equation but I am not able to understand the concept of ionisation state? What are ionization states actually?
- 18.7k
3
votes
0
answers
713
views
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 ...
- 163
3
votes
0
answers
71
views
H-alpha velocity fields of spirals falling into a cluster
What kind of impact would you expect ram pressure stripping / tidal interactions / harassment / interactions with the cluster potential (etc!) to have on the h-alpha velocity fields of infalling ...
- 17.6k
2
votes
0
answers
51
views
How to identify Hydrogen lines of slitless spectrograph of Type A9 star
Hi I am analysing slitless spectrograph of type A9 star Canopus. Here is as sample of the spectrograph.
I basically did a simple summing up of the columns and added the data (as a simple spectrum co- ...
2
votes
0
answers
56
views
Calculate change in spectral line intensity for a change in temperature
I am trying to do some simple modelling of spectral line emission. I am starting with some ALMA observations of a protoplanetary disk, where the emission from a particular molecule at frequency 344GHz ...
- 1,386
2
votes
0
answers
84
views
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 ...
- 156k
2
votes
0
answers
125
views
How does one estimate the mass of a galaxy using the Balmer break region?
I am currently reading the recent astrophysical paper "A population of red massive galaxies ~600Myr after the Big Bang'.
In the first paragraph/abstract it mentions, "It has been difficult ...
- 21