Question: Assume there are only two phases in the interstellar medium, both atomic. The first is the cold neutral medium (CNM), characterized by a kinetic temperature

Assume there are only two phases in the interstellar medium, both atomic. The first is the cold neutral medium (CNM), characterized by a kinetic temperature of 80K and the 21cm hydrogen line width (FWHM) of 2 km/s. The other phase is the warm neutral medium (WNM) and assume that it has a kinetic temperature of 8000 K and is characterized by a line width (FWHM) of 20 km/s. Assuming no turbulence, answer the following questions: (a) What column density of HI produces a line center optical depth in the 21-cm line of unity for both the CNM and the WNM phases? (b) Measurements of HI towards distance radio sources have shown a typical optical depth due to the CNM phase is 0.5. If the density of the CNM phase is 100  Assume there are only two phases in the interstellar medium, both, estimate the typical size and mass of these CGM clouds.

Transcribed image text

Step by Step Solution

There are 3 Steps involved in it

1 Expert Approved Answer
Step: 1 Unlock blur-text-image
Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock
Step: 3 Unlock

Students Have Also Explored These Related Chemical Engineering Questions!