Open AccessThe local environment of H ii galaxies
Author(s) -
Telles Eduardo,
Maddox Steve
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03116.x
Subject(s) - physics , astrophysics , dwarf galaxy , galaxy , luminous infrared galaxy , astronomy , dwarf spheroidal galaxy , intergalactic travel , peculiar galaxy , galaxy group , redshift
We have carried out an investigation of the environments of low redshift H ii galaxies by cross‐correlating their positions on the sky with those of faint field galaxies in the Automatic Plate Measuring Machine (APM) catalogues. We address the question of whether violent star formation in H ii galaxies is induced by low‐mass companions by statistically estimating the mean space density of galaxies around them. We argue that even if low‐mass companions were mainly intergalactic H i clouds, their optical counterparts should be detectable at faint limits of the APM scans. A significantly positive signal is detected for the H ii galaxy–APM galaxy angular cross‐correlation function, but the amplitude is poorly determined. The projected cross‐correlation function has a higher signal‐to‐noise ratio, and suggests that the amplitude is slightly lower than for normal field galaxies. This implies that these bursting dwarf galaxies inhabit slightly lower density environments than those of normal field galaxies, consistent with other studies of emission‐line galaxies. This suggests that in these dwarf starburst galaxies, star formation is not always triggered by tidal interactions, and a significant fraction must have a different origin.