FAST discovery of long tidal tails in NGC 4490/85

• DOI: 10.48550/arxiv.2304.13964
• Publication Date: 2023-01-01
• Authors: Yao Liu; Ming Zhu; Haiyang Yu; Mei Ai; Peng Jiang; Siqi Liu; Ruilei Zhou; Lixia Yuan
• Keywords: Astrophysics of Galaxies (astro-ph.GA); 0103 physical sciences; FOS: Physical sciences; Astrophysics - Astrophysics of Galaxies; 01 natural sciences

We report the discovery of a 100 kpc HI tail in merging galaxy pair NGC 4490/85 detected by Five-Hundred-meter Aperture Spherical radio Telescope (FAST). The tidal tails extended both south and north directions, they are much longer than that reported previously based on VLA interferometric maps. is surrounded large gas envelope, starburst low metallicity dwarf MAPS 1231+42 found to be connected with indicating interaction trigged intense star formation it. Based fact one order magnitude lower two disks 4490 4485, we speculate near this should primordial could due inflow from circum-galactic medium (CGM). also collimated component pointing at nearby KK 149, suggesting might interacting pair. discuss possible origin long envelope system new data FAST.