The environment of HII galaxies

摘要: Recent morphological studies (Telles \& Terlevich 1994) of HII galaxies, i.e. dwarf galaxies dominated by a very luminous starburst, have indicated that tend to show distorted morphology suggestive tidal interactions triggering the present starburst while low luminosity be instead symmetric and regular. To check origin in we searched for companions neighbourhood sample 51 galaxies. We found only 12 neighbour within projected distance 1 Mpc 250 \kmsec~ velocity difference, these 12, 4 (M$_B <$ --19) neighbour. Surprisingly, isolated high disturbed with neighbours regular Furthermore, metal abundance equivalent width emission lines do not depend on presence companion. These results are opposed simple expectations if interaction bright companion is main mechanism starbursts. also loose group no For this, there additional difficulty understanding how starbursts synchronized time scales less than $10^7$ yrs systems separated $\sim$ 1-2 Mpc.