The multifrequency radio continuum and 21cm H i observations of five blue compact dwarf ( BCD ) galaxies , Mrk 104 , Mrk 108 , Mrk 1039 , Mrk 1069 and I Zw 97 using the Giant Meterwave Radio Telescope ( GMRT ) are presented here .
Radio continuum emission at 610 MHz and 325 MHz is detected from all the observed galaxies whereas only a few are detected at 240 MHz .
In our sample , three galaxies ( Mrk 104 , Mrk 108 and Mrk 1039 ) are members of groups and two galaxies ( Mrk 1069 and I Zw 97 ) are isolated galaxies .
The radio emission from Mrk 104 and Mrk 108 is seen to encompass the entire optical galaxy whereas the radio emission from Mrk 1039 , Mrk 1069 , I Zw 97 is confined to massive H ii regions .
This , we suggest , indicates that the star formation in the latter group of galaxies has recently been triggered and that the environment in which the galaxy is evolving plays a role .
Star formation rates ( SFR ) calculated from 610 MHz emission is in the range 0.01 - 0.1 M _ { \odot } yr ^ { -1 } ; this is similar to the SFR obtained for individual star forming regions in BCDs .
The integrated radio spectra of four galaxies are modelled over the frequency range where data is available .
We find that two of the galaxies Mrk 1069 and Mrk 1039 , show a turnover at low frequencies which is well fitted by free-free absorption whereas the other two galaxies , Mrk 104 and Mrk 108 , show a power law at the lowest GMRT frequencies .
The flatter spectrum , localized star formation and radio continuum in isolated galaxies lend support to stochastic self-propagating star formation ( SSPSF ) .
The H i observations of four galaxies Mrk 104 , Mrk 108 , Mrk 1039 and Mrk 1069 show extended disks as large as \sim 1.1 - 6 times the optical size .
All the observed BCDs ( except Mrk 104 ) show rotating disk with a half power width of \sim 50 - 124 km s ^ { -1 } .
Solid body rotation is common in our sample .
We note that the tidal dwarf ( TD ) origin is possible for two of the BCDs in our sample .