Questions tagged [disk]
The disk tag has no usage guidance.
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Total scattered flux and polarization for a ring of dust particles close to a star
I have an important problem and maybe some of you can help me with the following question:
I have a mathematical expression for the total scattered flux in Jansky and the total linear polarized flux (...
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Why did supernova 1987A's "String of 'Cosmic Pearls'" appear to be so lumpy 20 years later? Is it still?
NASA's A String of 'Cosmic Pearls' surrounds an exploding star is beautiful and the page says:
This image shows the entire region around the supernova. The most prominent feature in the image is a ...
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How to approximate the distance at which the thin disk peaks along a given LOS from Earth for a given galactic coordinate per 1 sq deg?
The density of stars drops off exponentially from the center of the galaxy and can be approximated as follows using a cylindrical coordinate system:
$$ \rho(R, z) = \rho_0 \exp \frac{-R}{h_R} \ \exp \...
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Are warm circumstellar debris disks still able to be detected at sub-millimeter wavelengths?
At these wavelengths a survey is more sensitive to detecting relatively cool disks (T<100k), but would a telescope operating in the sub-millimeter be less sensitive to warm debris disk than say, a ...
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Why isn't the black hole white?
I recently saw the first image of a black hole. As I understood, it is covered with bright, hot matter. In this case, how can we see the black disk (event horizon), instead of a bright disk due to the ...
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Need help on Springel model for galaxy simulation
I am working on a code for galactic dynamics simulation. Initial conditions (positions and velocities) are based on a model with a massive dark halo and a thin exponential disk.
Now, from the ...
user16492
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Difference between "planetary ring" and "circumstellar disk"?
Related: Do/Can Ringed Stars Exist?
Is there any particular difference, in behavior or properties, between a planetary ring system and a circumstellar disk? Or is the only real difference a matter of ...
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How is the maximum density in a circumstellar disk determined?
I'm working with some equations to model the evolution of a circumstellar disk. One of the equations is
$$\rho(r)=Ce^{-\frac{(r-r_{peak})^2}{2 \sigma ^2}}$$
where $\rho$ is density, $r$ is the ...
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Number density of stars on the Galactic plane
The number density of stars (e.g. the number of stars per cubic parsec) is given by
$$N(z) = N(0) e^{-|z|/h}$$
where $z$ is the height above the Galactic plane, $h$ is the scale height for a specific ...
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