论文标题
JWST/MIRI MRS揭示的NGC 7319中的低功率喷射互动
Low-power jet-ISM interaction in NGC 7319 revealed by JWST/MIRI MRS
论文作者
论文摘要
我们提出了NGC7319的JWST/MIRI MRS光谱，这是Stephan五重奏中最大的星系，是早期释放观测（ERO）的一部分。 NGC7319拥有2型活动的银河核（AGN）和低功率无线电射流（L_1.4GHz = 3.3x10^22 W Hz^-1），在430 PC（N2）和1.5 kpc（s2）的两个不对称无线电热点预测距离距离无线电核心的差异。 MRS数据表明，银河系磁盘中的分子材料会减速射流并导致该长度不对称。我们发现，在磁盘中的射流轴和尘埃泳道之间的交点处，温暖和热H_2（T_W = 330+-40 K，T_H = 900+-60 K）的发射增强。这种发射与无线电热点N2（热点更接近核心）是一致的，这表明喷气媒介媒介介质（ISM）相互作用会减速射流。相反，更遥远的热点处的中红外发射更淡，更高度电离，并且具有较低的H_2激发，这表明射流可以发展到更远的距离。在N2无线电热点处，离子化的气体质量（M_ION =（2.4-12）X10^5 msun）与温暖的H_2相当，但前者更动荡（Sigma_ion〜300 vs. Sigma_h2〜150 km/s），因此电离气体的机械能量是高度〜1.3-10倍。从这些估计值中，我们发现，在N2处这两个ISM相中，射流能量的仅<1％仍然是机械能。我们还发现靠近无线电热点的扩展（r> 0.3-1.5 kpc）高电源发射（[mgv]，[nevi]和[nevi]）。对NGC7319的初步分析显示了Miri/MRS的潜力，研究了由于无线电飞机而引起的AGN反馈机制及其在星系中尘埃刺激的中央区域中的辐射场及其辐射场的潜力。理解这些机制是发展星系进化的宇宙学模拟的重要组成部分。
We present JWST/MIRI MRS spectroscopy of NGC7319, the largest galaxy in the Stephan's Quintet, observed as part of the Early Release Observations (ERO). NGC7319 hosts a type 2 active galactic nucleus (AGN) and a low-power radio jet (L_1.4GHz=3.3x10^22 W Hz^-1) with two asymmetric radio hotspots at 430 pc (N2) and 1.5 kpc (S2) projected distances from the unresolved radio core. The MRS data suggest that the molecular material in the disk of the galaxy decelerates the jet and causes this length asymmetry. We find enhanced emission from warm and hot H_2 (T_w=330+-40 K, T_h=900+-60 K) and ionized gas at the intersection between the jet axis and dust lanes in the disk. This emission is coincident with the radio hotspot N2, the hotspot closer to the core, suggesting that the jet-interstellar medium (ISM) interaction decelerates the jet. Conversely, the mid-infrared emission at the more distant hotspot is fainter, more highly ionized, and with lower H_2 excitation, suggesting a more diffuse atomic environment where the jet can progress to farther distances. At the N2 radio hotspot, the ionized gas mass (M_ion=(2.4-12)x10^5 Msun) is comparable to that of the warm H_2, but the former is more turbulent (sigma_ion~300 vs. sigma_H2~150 km/s), so the mechanical energy of the ionized gas is ~1.3-10 times higher. From these estimates, we find that only <1% of the jet energy remains as mechanical energy in these two ISM phases at N2. We also find extended (r>0.3-1.5 kpc) high-ionization emission ([MgV], [NeVI], and [NeV]) close to the radio hotspots. This initial analysis of NGC7319 shows the potential of MIRI/MRS to investigate the AGN feedback mechanisms due to radio jets and their radiation field in the, often heavily dust-enshrouded, central regions of galaxies. Understanding these mechanisms is an essential ingredient in the development of cosmological simulations of galaxy evolution.
