论文标题
部分可观测时空混沌系统的无模型预测
Simulating Jellyfish Galaxies: A Case Study for a Gas-Rich Dwarf Galaxy
论文作者
论文摘要
我们使用具有多相星际培养基（ISM）的富含气体矮星系的辐射流动力模拟研究了水母星系的形成。我们发现，RAM压缩（RPS）ISM是距银河平面10 kpc内近尾流中分子块的主要来源，而原位地层是富含气体富含星系的遥远尾巴中密集气体的主要通道。近尾流中只有20％的分子团来自簇内培养基（ICM）；但是，由于RPS气的冷却时间往往很短，因此从银河中心的$ 80 \，{\ rm kpc} $的团块中的分数达到50％。尾部区域的恒星形成率为$ 0.001-0.01 \，{\ rm m _ {\ odot} \，yr^{ - 1}} $，大多数尾星出生在剥落的尾流中，在10 kpc以内从银河系平面造成的10 kpc。这些恒星在尾部诱导明亮的H $α$斑点，而H $α$ tails fainter比$ 6 \ times10^{38} \，{\ rm erg \ \，s^{ - 1} \，kpc^{ - 2}} $主要通过碰撞辐射和热量应造成的混合形成。我们还发现，被剥离的尾巴具有中间X射线至H $α$表面亮度比（1.5 $ \ Lessim f _ {\ rm X}/f _ {\ rmHα} \ rmhα} \ lysesim $ 20），与ISM（$ \ simsim $ 1.5）或pure icm（$ \ $ \ $ \ $ \ gg $ 20）相比。我们的结果表明，当来自富含气体的星系中的ISM被强烈的RAM压力剥离，与ICM混合并增强尾部的冷却时，水母的特征会出现。
We investigate the formation of jellyfish galaxies using radiation-hydrodynamic simulations of gas-rich dwarf galaxies with a multi-phase interstellar medium (ISM). We find that the ram-pressure-stripped (RPS) ISM is the dominant source of molecular clumps in the near wake within 10 kpc from the galactic plane, while in-situ formation is the major channel for dense gas in the distant tail of the gas-rich galaxy. Only 20% of the molecular clumps in the near wake originate from the intracluster medium (ICM); however, the fraction reaches 50% in the clumps located at $80\,{\rm kpc}$ from the galactic center since the cooling time of the RPS gas tends to be short due to the ISM--ICM mixing ($\lesssim$ 10 Myr). The tail region exhibits a star formation rate of $0.001-0.01\,{\rm M_{\odot}\,yr^{-1}}$, and most of the tail stars are born in the stripped wake within 10 kpc from the galactic plane. These stars induce bright H$α$ blobs in the tail, while H$α$ tails fainter than $6\times10^{38}\,{\rm erg\,s^{-1}\,kpc^{-2}}$ are mostly formed via collisional radiation and heating due to mixing. We also find that the stripped tails have intermediate X-ray to H$α$ surface brightness ratios (1.5$\lesssim F_{\rm X}/F_{\rm Hα}\lesssim$20), compared to the ISM ($\lesssim$1.5) or pure ICM ($\gg$20). Our results suggest that jellyfish features emerge when the ISM from gas-rich galaxies is stripped by strong ram pressure, mixes with the ICM, and enhances the cooling in the tail.
