Questions tagged [interstellar-medium]
Questions about the gas that lays between stars in galaxies.
8 questions with no upvoted or accepted answers
6
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0
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Cooling timescale for an interstellar dust grain
I would like to estimate the cooling timescale for an interstellar dust grain, starting at 200K, down to 100 K.
The equation I have come up with is:
$\displaystyle t_{cooling} = \frac{mC\Delta T}{Q_{...
- 1,386
5
votes
0
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90
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Significantly blueshifted Lyman-$\alpha$
Lyman-$\alpha$ line in galaxies is notably known to show a double peaked profile, mainly due to its scattering in a moving medium, see e.g., the very recent Matthee et al. 2021, The X-SHOOTER Lyman-α ...
user38152
3
votes
0
answers
166
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Hydrogen Frost Line? Where, if anywhere, is it cold enough for Oort Cloud objects or rogue planets to have solid hydrogen on their surfaces?
I like the idea of Oort Cloud objects all being crusted with a thin layer of hydrogen snow, though what little information I've managed to find on the topic seems to imply that that is unlikely, ...
- 241
3
votes
0
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104
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For chemical reactions occurring in the interstellar medium, which involve metal-ions, will the metal ions be solvated or not?
Usually, metal-ions in terrestrial chemistry will be solvated - either by gas-phase solvent molecules or by liquid-phase solvent molecules. But the interstellar medium (ISM) is never in local ...
- 83
2
votes
0
answers
29
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Software for simulating/calculating a known EMW pulse propagating in ISM, including dispersion, scattering, etc
Could you please let me know, if there is any software/code/tool for simulating/calculating the result of a short EMW pulse (waveform is exactly known) propagating in the ISM for long distance, ...
- 21
1
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0
answers
70
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Why does rotation prevent the further contraction of the cloud?
In the book Horizons: Exploring the Universe (2018) by M.Seeds and D.Backman, chapter 9, page 170-171, it states that:
At least four factors resist the
compression of an interstellar gas cloud, and ...
- 1,306
1
vote
0
answers
141
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Virial coefficient when computing dynamical mass enclosed by a rotating galactic disk of gas
Suppose I have a large thin disk of rotating gas in a galaxy -- the disk has a maximum inclination-corrected $V_{max}$ and a maximum radial extent of $R_{max}$ corresponding to that $V_{max}$ ...
- 723
0
votes
0
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34
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Electron Temperature of a Gas Cloud
Would a gas cloud made of HII and OIII have a higher electron temperature than a cloud just consisting of HII? I understand that electron temperature is the temperature of the electrons in a plasma, ...
- 1,047