Super-luminous supernovae ( SLSNe ) of type Ic have a tendency to occur in faint host galaxies which are likely to have low mass and low metallicity .
PTF12dam is one of the closest and best studied super-luminous explosions that has a broad and slowly fading lightcurve similar to SN 2007bi .
Here we present new photometry and spectroscopy for PTF12dam from 200-500 days ( rest-frame ) after peak and a detailed analysis of the host galaxy ( SDSS J142446.21+461348.6 at z = 0.107 ) .
Using deep templates and image subtraction we show that the lightcurve can be fit with a magnetar model if escape of high-energy gamma rays is taken into account .
The full bolometric lightcurve from -53 to +399 days ( with respect to peak ) can not be fit satisfactorily with the pair-instability models .
An alternative model of interaction with a dense CSM produces a good fit to the data although this requires a very large mass ( \sim 13 M _ { \odot } ) of hydrogen free CSM .
The host galaxy is a compact dwarf ( physical size \sim 1.9 kpc ) and with M _ { g } = -19.33 \pm 0.10 , it is the brightest nearby SLSN Ic host discovered so far .
The host is a low mass system ( 2.8 \times 10 ^ { 8 } M _ { \odot } ) with a star-formation rate ( 5.0 M _ { \odot } yr ^ { -1 } ) , which implies a very high specific star-formation rate ( 17.9 Gyr ^ { -1 } ) .
The remarkably strong nebular emission provide detections of the [ O iii ] \lambda 4363 and [ O ii ] \lambda \lambda 7320 , 7330 auroral lines and an accurate oxygen abundance of 12 + \log { ( O / H ) } = 8.05 \pm 0.09 .
We show here that they are at the extreme end of the metallicity distribution of dwarf galaxies and propose that low metallicity is a requirement to produce these rare and peculiar supernovae .