Optical Extinction Help Needed: Calculating A_v for Spherical Cloud

In summary, the task is to determine the maximum optical extinction, represented by the function A_{v}(\alpha), for a spherical cloud with a gas to dust ratio of 100, mass of 1 M(sun), and diameter of 1pc. The radial density of the cloud can be described by a power law, with the equation \rho(r) \propto r^{-\alpha}. The relevant equations for this problem are N(H)=6.93*10^{21} cm^{-2}*A_{v}/R_{v} and R_{v}=3. Despite finding some calculations for extinction values based on flux, the solution process is unclear and guidance is needed.
  • #1
Ayame17
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Help Needed! Optical extinction

Homework Statement



Spherical cloud (gas to dust ratio 100) with mass = 1 M(sun), diameter = 1pc. Radial density can be described by power law (see below). Determine the maximum optical extinction, ie. the function [tex]A_{v}(\alpha)[/tex].

Homework Equations



Power law: [tex]\rho(r) \propto r^{-\alpha}[/tex]

You may use [tex]N(H)=6.93*10^{21} cm^{-2}*A_{v}/R_{v}[/tex] and [tex]R_{v}=3[/tex]

The Attempt at a Solution



I've looked up column density and found extinction values calculated by flux, but simply can't see where to even begin. A nudge in the right direction would be so very helpful!
 
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  • #2
Please, anyone?
 

Related to Optical Extinction Help Needed: Calculating A_v for Spherical Cloud

What is optical extinction?

Optical extinction is the process by which light is absorbed or scattered by particles in a medium, thereby reducing its intensity as it passes through the medium.

What is A_v?

A_v is the visual extinction, which is a measure of the amount of extinction at a specific wavelength, typically in the visible range.

How is A_v calculated for a spherical cloud?

A_v for a spherical cloud can be calculated using the equation A_v = 1.086 * N * sigma, where N is the column density of the cloud and sigma is the cross-section per particle. This equation assumes that the cloud is optically thin.

What are the factors that affect A_v?

The factors that affect A_v include the density and composition of the medium, the size and shape of the particles, and the wavelength of the light passing through the medium.

Why is calculating A_v important in astronomy?

Calculating A_v is important in astronomy because it can help us understand the properties of interstellar clouds, such as their composition and density. It also allows us to correct for the effects of extinction when observing distant objects, such as stars and galaxies.

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