LOFAR observations at 144 MHz have revealed large-scale radio sources in the unrelaxed galaxy cluster Abell 1132 .
The cluster hosts diffuse radio emission on scales of \sim 650 kpc near the cluster center and a head-tail ( HT ) radio galaxy , extending up to 1 Mpc , south of the cluster center .
The central diffuse radio emission is not seen in NVSS , FIRST , WENSS , nor in C & D array VLA observations at 1.4 GHz , but is detected in our follow-up GMRT observations at 325 MHz .
Using LOFAR and GMRT data , we determine the spectral index of the central diffuse emission to be \alpha = -1.75 \pm 0.19 ( S \propto \nu ^ { \alpha } ) .
We classify this emission as an ultra-steep spectrum radio halo and discuss the possible implications for the physical origin of radio halos .
The HT radio galaxy shows narrow , collimated emission extending up to 1 Mpc and another 300 kpc of more diffuse , disturbed emission , giving a full projected linear size of 1.3 Mpc – classifying it as a giant radio galaxy ( GRG ) and making it the longest HT found to date .
The head of the GRG coincides with an elliptical galaxy ( SDSS J105851.01 + 564308.5 ) belonging to Abell 1132 .
In our LOFAR image , there appears to be a connection between the radio halo and the GRG .
The turbulence that may have produced the halo may have also affected the tail of the GRG .
In turn , the GRG may have provided seed electrons for the radio halo .