Atomic and molecular gas in the merger galaxy NGC 1316 (Fornax A) and its environment

We present and interpret observations of atomic and molecular gas toward th e southern elliptical galaxy NGC 1316 (Fornax A), a strong double-lobe radi o source with a disturbed optical morphology that includes numerous shells and loops. The (CO)-C-12(1-0), (CO)-C-12(2-1), and Hi observations were mad e with SEST and the VLA. CO emission corresponding to a total molecular hyd rogen mass of similar to 5 x 10(8) M-. was detected towards the central pos ition as well as northwest and southeast of the nucleus in the regions of t he dust patches. The origin of that gas is likely external and due to accre tion of one or several small gas-rich galaxies. Hi was not detected in the central region of NGC 1316, but similar to 2 x 10(7) M-. of atomic gas was found towards the giant Hii region discovered by Schweizer (1980) located 6 .'7 (or 36.2 kpc) from the nucleus. Hi was also found at three other locati ons in the outer part of NGC 1316. The Hi distributions and kinematics of t he two nearby spiral companions of NGC 1316, NGC 1317 (a barred galaxy to t he north) and NGC 1310 (to the west) could be studied. Both galaxies have u nusually small HI disks that may have been affected by ram-pressure strippi ng.