Unanswered Questions
57 questions with no upvoted or accepted answers
2
votes
0
answers
63
views
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/...
- 41
2
votes
0
answers
62
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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 ...
- 323
2
votes
0
answers
33
views
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
2
votes
0
answers
76
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Correction to inverse square law for cosmology
While reading about the discovery of quasars and the spectroscopic analysis of 3C 273 in this paper by Maarten Schmidt, I came across the following quote:
At these distances, corrections to ...
- 2,600
2
votes
0
answers
120
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Source for Identification of Balmer Hydrogen Absorption Lines
I'm working on an assignment, where I have to classify stars using the raw data of the telescope. I'm now trying to calibrate the pixel to armstrong ratio, and for that I need to identify the ...
- 141
2
votes
0
answers
102
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Can all astronomical signals be considered Gaussian noise?
While studying the techniques astronomers use to mitigate radio frequency interference (RFI) I found it's often assumed that astronomical signals are (band-limited) Gaussian noise. Is this a ...
- 21
1
vote
0
answers
24
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Obtaining Transit Spectrum for Celestial Bodies Using JWST NIRSPEC
I've recently been tasked with obtaining transit spectrum data for some fascinating celestial bodies, including Ceres, Enceladus, Ganymede, Io, and Titan. The goal is to compare their transit spectra ...
1
vote
0
answers
22
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Using Gaia Passbands with L_nu coordinates
I am trying to find the coordinates of my bundles of gas on the gaia ($G, G_{bp}-G_{rp}$) hr diagram. I have its spectrum in $\nu L_\nu$ coordinates. Thus far, my attempts have mainly been to ...
- 53
1
vote
0
answers
49
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Space telescope spectroscopic data for stellar classification using Wien's law
My goal is to make a simple project which consists of classifying stars by applying Wien's displacement law.
I need public spectroscopic data about different stars from a space telescope, so that I ...
- 30.7k
1
vote
0
answers
58
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How do nuJ(nu) units work?
I'm working with (Nublado) Cloudy, which is essentially a spectral modelling tool for stellar matter. Using the software, I model my own stellar object and obtain its continuum.
According to Hazy, ...
- 155k
1
vote
0
answers
53
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Determining the rotation curve of a galaxy via given spectroscopic data
Here is the data analysis question from IOAA-2011,
1. Weighing a galaxy: The image 8.2 shows a photograph of the spiral
galaxy NGC 7083, which lies at a distance of 40 Mpc, and image 8.3 a
fragment of ...
1
vote
0
answers
61
views
Could we optically observe metallic hydrogen in space?
As many calculations have been done on whether metallic hydrogen is metastable or not in low-pressure environment, It occurred to me that by the fact that we have not observed any metallic hydrogen so ...
- 119
1
vote
0
answers
243
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Relationships between G magnitude, Johnson V magnitude, and spectral type of stars?
I'm simulating a population of binary stars for a summer research project. I'm adding uncertainties to my simulated observables such as angular position and radial (line of sight) velocity. I'm using ...
- 5,636
1
vote
0
answers
60
views
Error of bisector method
How to determine the error of bisector velocity span? I have found the article below, but I do not know what all quantities mean. What is the number of lines in the mask? How to find out x? How to ...
- 18.7k
1
vote
0
answers
102
views
H alpha - double peak (Be star)
What is the double peak in this case, please? What does the third mean? Many thanks
- 17.6k