vikasagartha said:Hi! I am an student w/ little background in astronomy taking an upper level astro course, and am having some difficulty with basic concepts. Any help is appreciated.
Why are cosmic rays so important for the heating of molecular clouds? I read that hard xrays can heat as well, while soft xrays cannot. Help?
The ISM is the matter and radiation that exists in the space between stars in a galaxy. It is made up of gas, dust, and cosmic rays.
Heating and cooling in the ISM is primarily driven by interactions between particles and radiation. High-energy radiation from stars can heat up the gas and dust in the ISM, while collisions between particles can also transfer heat. Cooling occurs through the emission of radiation from particles, which helps regulate the temperature of the ISM.
The main factors that influence heating and cooling in the ISM are the density and composition of the gas and dust, the intensity and type of radiation present, and the overall energy balance of the ISM. Other factors such as magnetic fields and shock waves can also play a role.
The heating and cooling processes in the ISM are closely linked to the formation of stars. The heating of gas and dust can trigger the collapse of molecular clouds, leading to the formation of new stars. At the same time, the cooling of the ISM helps regulate the temperature and density of the gas, which is crucial for the formation and evolution of stars.
Yes, we can observe the heating and cooling processes in the ISM through various telescopes and instruments. For example, infrared and submillimeter telescopes can detect the heat emitted by dust particles, while X-ray telescopes can observe the high-energy radiation from hot gas in the ISM. These observations help us better understand the physical processes at work in the ISM.