F. Bochicchio, F. Forastiere, S. Mallone, C. Nuccetelli and F. Sera 1 Istituto Superiore di Sanità, Physics Laboratory, Viale Regina Elena 299, I-00161 Roma, Italy. 2 Osservatorio Epidemiologico Regione Lazio, Analytic Epidemiology Unit, Via S.Costanza 53, I-00198 Roma, Italy. 3 Istituto Superiore di Sanità, Physics Laboratory, Viale Regina Elena 299, I-00161 Roma, Italy (Present address: Istit...

We present VLA H i observations and UH88 ′′ deep optical Band R-band observations of the IR luminous merger Arp 299 (= NGC 3690 + IC 694). These data reveal a gas-rich (M HI = 3.3 × 10 9 M ⊙) optically faint (µ B ∼ >27 mag arcsec −2 , µ R ∼ >26 mag arcsec −2) tidal tail with a length of over 180 kpc. The size of this tidal feature necessitates an old interaction age for the merger (∼ >750 Myr s...

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