Detection of a radio-filled X-ray cavity within the interstellar medium of NGC 5141

We present the first Chandra detection of a single X-ray cavity within the interstellar medium of the small Fanaroff-Riley type I radio galaxy NGC 5141, The X-ray surface brightness depression, located kpc away from the galaxy center, is projected on the northern radio lobe, which is completely contained within the galaxy. The thermal gas surrounding the cavity, which extends to similar or equal to 20 kpc, has a bolometric X-ray luminosity (0.1-100 keV) of L-X approximate to 2 x 10(40) erg s(-1) and a temperature of kT approximate to 0.8 keV. We calculated the total energy (E-cav = 4PV approximate to 10(55) erg) required to inflate the cavity and its age 9 Myrs), assuming that it is filled with relativistic particles as and rises buoyantly. The inferred total cavity power is low as P-cav = E-cav/t(cav) approximate to 6 x 10(40) erg s(-1), which is the lowest one among the radio-filled systems. Comparing P-cav to the bolometric X-ray luminosity (i.e., the cooling luminosity), we conclude that NGC 5141's central active galactic nucleus can heat the interstellar medium and balance its cooling luminosity, confirming that the P-cav - L-cool relation, mainly tested on groups and clusters, also works for such a low-power system.