IRAS observations of the star-forming region Cep OB4

A detailed study of the infrared radiation of star-forming region Cep OB4 based on the IRAS data shows that the molecular cloud in the vicinity of young stellar cluster Be 59 is originally clumpy. Be 59 was born in the rear of a cloud with an average density of (1-2) ×10 ² cm ^-3. The strong ionization radiation and wind from the Be 59 have caused a blister HII region with a radius of 5 pc and a related infrared source on its natal cloud. The ionization radiation has also passed through the intercloud medium and got to the surfaces of two nearby clouds, forming the ionization fronts seen mainly edge-on as well as the compressed and heated neutral material shell. Although there are a large number of young star in this region, the formation of massive stars has already stopped. The infrared emission of the complex is mainly caused by thermal equilibrium emission of standard dust grains. However, the 25 μm emission on the HII region close to the Be 59 is significantly enhanced. This enhancement may be originated from a new type dust grain, which is mixed with ionized gas.