A search for interstellar bubbles surrounding massive stars in Perseus OB1

Abstract

We have examined the interstellar medium in the vicinity of massive stars belonging to the Per OB1 association based on neutral hydrogen 21 cm observations obtained with the 100 m radio telescope at Effelsberg (HPBW = 8′.4) and complementary data from the Leiden-Dwingeloo H I Survey (HPBW = 36′). The higher angular resolution H I observations allowed us to discover probable wind-blown bubbles related to four massive stars in the association, namely, HD 14442 [O5n(f)p], HD 14947 [O5If+], HD 13022 [O9.5II-III((n))], and HD 13338 [O9.5V], while the detection of a wind-blown bubble associated with HD 16691 [O5If+] is less conclusive. A clear H I shell coincident in position with two B1III stars (HD 15233 and Hilt 311) was also detected. Some of these features also have infrared and/or molecular counterparts. The energetics of the structures related to each massive star is analyzed. The new H I interstellar bubbles appear to be similar to the ones found surrounding Wolf-Rayet stars and other Of stars. The large-scale maps obtained using the lower angular resolution H I data show that most of the early-type stars belonging to Per OB1 are placed in a region of low H I emission. The association could have blown a H I shell of about 350 × 550 pc in size. This large H I shell has an infrared counterpart.