Astronomy, Intensity from Given Flux

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To calculate the intensity of a light source with a uniform intensity within a 3 arcmin diameter circle, the flux reaching the observer is given as 10^(-16) erg cm^(-2) s^(-1). The relevant equation for this calculation involves integrating over the solid angle, which can be simplified since the intensity is constant. The area of the circle can be determined using the radius of 1.5 arcmin, converting it to steradians for the calculation. By dividing the flux by the angular area, the uniform intensity can be derived. Understanding these concepts is crucial for accurately determining the intensity from the given flux.
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A light source has uniform intensity I(with respect to wavelength) within a
circle of diameter 3 arcmin on the sky. The flux of radiation reaching the observer is
10^(−16) erg cm^(−2) s^(−1). Calculate the intensity of the light from this source.


Relevent Equations:

This is where my confusion comes in, I'm not really sure what the relavant equations are. The only equation I have found in the textbook is this:

F = Integral (d\omega)cos\theta

(I can't seem to get the latex to work correctly, I hope this makes sense as is).

I also know flux is watts per unit area, but I'm new to this on the astronomy side. I also know an erg is 10^-7 Ws. How would I use the 3 arcmin, would I find the area of a circle with 1.5 arcmin radius? Don't you need the distance to be able to calculate the flux? Any hints to get started would be great.
 
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The flux should be the integral over the angular area (sterradians) of the intensity. Since the intensity is claimed to be constant, presumably you can divide the flux by the angular area to obtain the uniform intensity.
 
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