Changes between Version 2 and Version 3 of u/erica/CF_coldens

Timestamp:

01/08/15 14:23:17 (10 years ago)

Author:

Erica Kaminski

Comment:

—

u/erica/CF_coldens

@@ -3 +3 @@
 [[latex($\sum n_i dx = \bar{n} L_x$)]]
 
-which has the rather strange units of computational number density times computational length. We can not just assume that the resultant product will  have units of 1/computational length cubed. Thus, we can not simply multiply our projected quantity by lscale.
+which has the rather strange units of computational number density times computational length. We can not just assume that the resultant product will  have units of 1/computational length squared. Thus, we can not simply multiply our projected quantity by lscale^-2^ to get units of cm^-2^.
+
+Instead, we should multiply it by lscale*nscale. This will give us the correct units for column density, when lscale and nscale are in cgs. 
+
+For my specific data, my lscale is 1 pc, and my nscale is 1 (which just means it is in cgs by default). So the quantity the code gives for 'projected column density in computational units', can be thought of as being in pc/cm^3^. To convert this to 1/cm^2^, multiply by the conversion factor 1pc = 3.08567758 × 10^18^ cm.
 
 Instead, we should multiply our projected number density by nscale*lscale, if both scales are in cgs. That will give the quantity we are looking for, n in 1/cm^3^.