What is stochastic heating of very small grains?

[sonutabitha]

I recently came across a paper where there was a term ''stochastic heating of very small grains". I went through some papers on this area but I am still confused about it. What is the vibrational temperature associated with very small grains? Does temperature has got a meaning if it's a highly fluctuating quantity?

 

[John Park]

I'd imagine the time-average of a fluctuating temperature might be meaningful if you were considering processes that were slow compared to the fluctuations. Conversely if the fluctuations left individual particles in (time-dependent) thermal equilibrium I'd expect one could analyse the resulting situation.

A bit more context would help. Grains of what, where? Being heated by what? Your comment about vibrational temperature suggests the grains are close to molecular dimensions. Is that the case?

 

[sonutabitha]

I am talking about the very small grains in the interstellar medium.