| Title | The Blue Compact Dwarf Galaxy VCC 848 Formed by Dwarf-Dwarf Merging: HiGas, Star Formation, and Numerical Simulations |
| Authors | Zhang, Hong-Xin Smith, Rory Oh, Se-Heon Paudel, Sanjaya Duc, Pierre-Alain Boselli, Alessandro Cote, Patrick Ferrarese, Laura Gao, Yu Hunter, Deidre A. Puzia, Thomas H. Peng, Eric W. Rong, Yu Shin, Jihye Zhao, Yinghe |
| Affiliation | Univ Sci & Technol China, Dept Astron, Key Lab Res Galaxies & Cosmol, Hefei 230026, Anhui, Peoples R China Univ Sci & Technol China, Sch Astron & Space Sci, Hefei 230026, Anhui, Peoples R China Korea Astron & Space Sci Inst KASI, 776 Daedeokdae Ro, Daejeon 34055, South Korea Sejong Univ, Dept Phys & Astron, 209 Neungdong Ro, Seoul, South Korea Yonsei Univ, Dept Astron, Seoul 03722, South Korea Yonsei Univ, Ctr Galaxy Evolut Res, Seoul 03722, South Korea Univ Strasbourg, CNRS, Observ Astron Strasbourg, UMR 7550, F-67000 Strasbourg, France Aix Marseille Univ, CNRS, LAM Lab Astrophys Marseille, UMR 7326, F-13388 Marseille, France Natl Res Council Canada, Herzberg Astron & Astrophys Program, 5071 West Saanich Rd, Victoria, BC V9E 2E7, Canada Xiamen Univ, Dept Astron, Xiamen 361005, Fujian, Peoples R China Chinese Acad Sci, Purple Mt Observ, 10 Yuanhua Rd, Nanjing 210023, Peoples R China Lowell Observ, 1400 West Mars Hill Rd, Flagstaff, AZ 86001 USA Pontificia Univ Catolica Chile, Inst Astrofis, Santiago 7820436, Chile Peking Univ, Dept Astron, Beijing 100871, Peoples R China Peking Univ, Kavli Inst Astron & Astrophys, Beijing 100871, Peoples R China Chinese Acad Sci, Yunnan Observ, Kunming 650011, Yunnan, Peoples R China |
| Keywords | H-II REGIONS DIGITAL SKY SURVEY VIRGO CLUSTER NEARBY GALAXIES MAJOR MERGERS RAM-PRESSURE DARK-MATTER STARBURST GALAXIES HII-REGIONS MASS-LOSS |
| Issue Date | Sep-2020 |
| Publisher | ASTROPHYSICAL JOURNAL |
| Abstract | A clear link between a dwarf-dwarf merger event and enhanced star formation (SF) in the recent past was recently identified in the gas-dominated merger remnant VCC 848, offering by far the clearest view of a gas-rich late-stage dwarf-dwarf merger. We present a joint analysis of JVLA Hi emission line mapping, optical imaging, and numerical simulations of VCC 848 in order to examine the effect of the merger on the stellar and gaseous distributions. VCC 848 has less than 30% of its Hi gas concentrated within the central high-surface-brightness star-forming region, while the remaining Hi is entrained in outlying tidal features. Particularly, a well-defined tidal arm reachesN(Hi) comparable to the galaxy center but lacks SF. The molecular gas mass inferred from the current SF rate (SFR) dominates over the atomic gas mass in the central similar to 1.5 kpc. VCC 848 is consistent with being a main-sequence star-forming galaxy for itscurrentstellar mass and SFR. The Hii region luminosity distribution largely agrees with that of normal dwarf irregulars with similar luminosities, except that the brightest Hii region is extraordinarily luminous. OurN-body/hydrodynamical simulations imply that VCC 848 is a merger between a gas-dominated primary progenitor and a gas-bearing star-dominated secondary. The progenitors had their first passage on a near-radial noncoplanar orbit more than 1 Gyr ago. The merger did not build up a core as compact as typical compact dwarfs with a centralized starburst, which may be partly ascribed to the star-dominated nature of the secondary and, in a general sense, a negative stellar feedback following intense starbursts triggered at early stages of the merger. |
| URI | http://hdl.handle.net/20.500.11897/592014 |
| ISSN | 0004-637X |
| DOI | 10.3847/1538-4357/abab96 |
| Indexed | SCI(E) |
| Appears in Collections: | 物理学院 科维理天文与天体物理研究所 |
