# 研究成果・発表論文

## Gas stripping by radiation drag from an interstellar cloud

### Sato, Jun'ichi,   Umemura, Masayuki,   Sawada, Keisuke,   & Matsuyama, Shingo

##### 要旨
We perform two-dimensional hydrodynamic simulation of gas stripping by radiation drag from interstellar clouds moving in uniform radiation fields. To include relativistic radiation drag properly, the radiation hydrodynamic equation is solved taking into account the dilution of radiation fields by the optical depth of the cloud. As a result, it is found that the optically thin surface layers are effectively stripped by radiation drag from an optically thick gas cloud, and, simultaneously, the stripped gas loses momentum. The momentum loss time-scale is found to be on the order of 10$^8$ yr under the intensive radiation fields expected in the early phase of galaxy evolution. The present results show that the radiation drag is an effective mechanism for extracting angular momentum from the interstellar medium and allows it to accrete on to the galactic centre. Mass accretion driven by radiation drag may lead to the formation of a central supermassive black hole.