Changes between Version 30 and Version 31 of u/erica/radtimescales

Timestamp:

04/04/16 16:23:39 (10 years ago)

Author:

Erica Kaminski

Comment:

—

u/erica/radtimescales

@@ -256 +256 @@
 The time it takes a sound wave to travel from the center of the prestellar core, to the outer edge is:
 
-[[latex($t_{cross}=\frac{L}{C_s}$)]]
-
-where the sound speed for 10 K molecular gas is ~.2 km/s and L is .05 pc. This gives:
-
-[[latex($\boxed{t_{cross}=7.714e+12 ~s}$)]]
-
-or 244 KY.
-
-How long it takes the gas to respond to changes in the internal energy depends on the crossing time over some appropriate length scale.
+[[latex($t_{cross}=\frac{r}{C_s}$)]]
+
+where the sound speed for 10 K molecular gas is ~.2 km/s and r=.0069 pc. This gives:
+
+[[latex($\boxed{t_{cross}=~33~ kyr}$)]]
+
+
+How long it takes the gas density to changes in response to changes in thermal energy corresponds to the crossing time, for some appropriate length scale.
 
 ''' Freefall time '''