We present results from GMRT and Chandra observations of the NGC 1550 galaxy group .
Although previously thought of as relaxed , we show evidence that gas sloshing and active galactic nucleus ( AGN ) heating have affected the structure of the system .
The 610 and 235 MHz radio images show an asymmetric jet - lobe structure with a total size of \sim 33 kpc , with a sharp kink at the base of the more extended western jet , and bending of the shorter eastern jet as it enters the lobe .
The 235 - 610 MHz spectral index map shows that both radio lobes have steep spectral indices ( \alpha _ { 235 } ^ { 610 } \geq - 1.5 ) indicating the presence of an old electron population .
The X-ray images reveal an asymmetric structure in the hot gas correlated with the radio structure , as well as potential cavities coincident with the radio lobes , with rims and arms of gas that may have been uplifted by the cavity expansion .
The X-ray residual map reveals an arc shaped structure to the east that resembles a sloshing cold front .
Radio spectral analysis suggests a radiative age of about 33 Myr for the source , comparable to the sloshing timescale and dynamical estimates of the age of the lobes .
An estimate of the mechanical energy required to inflate the cavities suggests that the AGN of NGC 1550 is capable of balancing radiative losses from the intragroup medium ( IGM ) and preventing excessive cooling , providing that the AGN jets are efficiently coupled to the IGM gas .
In conclusion , we find evidence of sloshing motions from both radio and X-ray structures , suggesting that NGC 1550 was perturbed by a minor merger or infalling galaxy about 33 Myr ago .