We use multi-wavelength ( 0.12 - 500 \mu m ) photometry from Herschel -ATLAS , WISE , UKIDSS , SDSS and GALEX , to study 23 nearby spheroidal galaxies with prominent dust lanes ( DLSGs ) .
DLSGs are considered to be remnants of recent minor mergers , making them ideal laboratories for studying both the interstellar medium ( ISM ) of spheroids and minor-merger-driven star formation in the nearby Universe .
The DLSGs exhibit star formation rates ( SFRs ) between 0.01 and 10 M _ { \odot } yr ^ { -1 } , with a median of 0.26 M _ { \odot } yr ^ { -1 } ( a factor of 3.5 greater than the average SG ) .
The median dust mass , dust-to-stellar mass ratio and dust temperature in these galaxies are around 10 ^ { 7.6 } M _ { \odot } , \approx 0.05 % and \approx 19.5 K respectively .
The dust masses are at least a factor of 50 greater than that expected from stellar mass loss and , like the SFRs , show no correlation with galaxy luminosity , suggesting that both the ISM and the star formation have external drivers .
Adopting literature gas-to-dust ratios and star formation histories derived from fits to the panchromatic photometry , we estimate that the median current and initial gas-to-stellar mass ratios in these systems are \approx 4 % and \approx 7 % respectively .
If , as indicated by recent work , minor mergers that drive star formation in spheroids with ( NUV - r ) > 3.8 ( the colour range of our DLSGs ) have stellar mass ratios between 1:6 and 1:10 , then the satellite gas fractions are likely \geq 50 % .