A strong correlation between bar strength and global star forming activity in isolated barred galaxies
Received 1 March 1999 / Accepted 26 August 1999
I have studied the relation between the global star formation activity and the bar structure in a sample of isolated barred galaxies. The star formation activity was quantified via the ratio between the IRAS fluxes at 25 µm and 100 µm. Two parameters were chosen to define the bar structure: the strength of the bar and the relative projected bar length. The strength of the bar was defined by , where a and b are the projected semi-major and semi-minor bar axis. The relative bar length was defined as: , where is one half of the projected total bar length and is the diameter of the 25 mag arcsec-2 magnitude isophote in the B band. We found a strong correlation between the star formation activity and . The regression line is given by , with a correlation coefficient of 0.9. The link is not so evident between the relative projected bar length and the star formation activity. But, it is noted that there is enhanced star formation activity in galaxies with strong bars and small relative bar lengths, .
Key words: galaxies: spiral galaxies: stellar content galaxies: statistics
© European Southern Observatory (ESO) 1999
Online publication: November 2, 1999