Strange Fireballs around a Merger Galaxy in the Coma Cluster of Galaxies
We found an unusual complex of narrow blue filaments, bright blue knots, and Ha emitting filaments and clouds (its morphology resembles a complex of fireballs (large meteors)) which extends up to 80 kpc to the south from a merging galaxy RB199 in the Coma cluster The narrow blue filaments extend in straight shapes toward the south from the galaxy and several bright blue knots are located at the south ends of the blue filaments. The Rc band absolute magnitudes, half light radii and estimated masses of the bright knots are ～ -12 13 mag, ~ 100 - 200 pc and ~ 106-7 M☉, respectively. Long narrow Ha emitting filaments are connected at the south edge of the knots. The average color of the fireballs is B- Rc ≈ 0.5, suggesting that most of the stars of which the fireballs is composed were formed within several times 108 yr. There is no Ha emission in the narrow blue filaments, whereas strong Ha and UV emission are emitted at the bright knots. These characteristics indicate that star formation has been recently ceased in the blue filaments and is now in progress in the bright knots. The gas stripped by some mechanism from the disk of RB199 may be traveling in the intergalactic space, forming stars and leaving the formed stars along its trajectories. Most plausible mechanism of forming the fireballs is ram pressure stripping by high speed collision between the galaxy and the hot intra-cluster medium.
galaxies clusters galaxies evolution galaxies dwarf
M. Yshida M. Yagi Y. Komiyama H. Furusawa N. Kashikawa Y. Koyama H. Yamanoi T. Hattori S. Okamura
Okayama Astrophysical Observatory, NAOJ,Okayama, Japan Optical Infrared Astronomy Division, NAOJ, Mitaka, Japan Subaru Telescope, NAOJ, Hilo, Hawaii, USA Tokyo University, Tokyo, Japan The Graduate University for Advanced Studies, Mitaka, Japan
国际会议
The 10th Asian-Pacific Regional International Astronomical Union Meeting(第十届亚洲及太平洋地区天文学大会 APRIM)
昆明
英文
338-339
2008-08-03（万方平台首次上网日期，不代表论文的发表时间）