arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2408.11548astro-ph.GA
收藏

CHIMPS2:银心分子区中的 $^{13}$CO $J = 3 \to 2$ 发射

CHIMPS2: $^{13}$CO $J = 3 \to 2$ emission in the Central Molecular Zone

S. M. King, T. J. T. Moore, J. D. Henshaw, S. N. Longmore, D. J. Eden, A. J. Rigby, E. Rosolowsky, K. Tahani, Y. Su, A. Yiping, X. Tang, S. Ragan, T. Liu, Y. -J. Kuan, R. Rani

AI总结:

本文介绍CHIMPS2巡天在银心分子区对$^{13}$CO J=3→2谱线的观测,揭示气体结构,并估计光学深度、柱密度和质量,发现年轻致密源更关联于CMZ致密气体。

摘要:

我们展示了作为银河系银心分子区(CMZ)的CO外差内银道面巡天2(CHIMPS2)项目一部分所获得的 $^{13}$CO 的 $J = 3 \to 2$ 跃迁的初始数据。观测覆盖了 $359^\circ \leq l \leq 1^\circ$ 和 $|b| \leq 0.5^\circ$ 的天区,角分辨率为19角秒,速度分辨率为1 km s$^{-1}$,在这些分辨率下均方根噪声 $T_A^* = 0.59$ K。我们的观测以更高的细节揭示了CMZ分子气体的复杂结构。结合 $^{12}$CO 的CHIMPS2数据,我们估计了中值光学深度 $τ_{13} = 0.087$。初步分析得出 $^{13}$CO 柱密度的中值范围为 $N(^{13}\text{CO})= 2$--$5 \times 10^{18}$ cm$^{-2}$,H$_2$ 柱密度的中值为 $N(\text{H}_2)= 4 \times 10^{22}$ cm$^{-2}$ 至 $1 \times 10^{23}$ cm$^{-2}$。我们基于 $N(\text{H}_2)$ 推导出总质量估计为 $M(\text{H}_2)= 2$--$6 \times 10^7\\, M_{\odot}$,与之前的研究一致。我们分析了 $^{13}$CO 的积分强度与Herschel Hi-GAL识别出的致密源面密度之间的关系,发现那些在500 $μ$m处探测到但未在70 $μ$m处探测到的较年轻Hi-GAL源比在70 $μ$m处明亮的源更紧密地遵循CMZ的致密气体。后者是活跃的恒星形成源,似乎更与前旋臂中的物质相关。

英文摘要:

We present the initial data for the ($J = 3 \to 2$) transition of $^{13}$CO obtained from the Central Molecular Zone (CMZ) of the Milky Way as part of the CO Heterodyne Inner Milky Way Plane Survey 2 (CHIMPS2). Covering $359^\circ \leq l \leq 1^\circ$ and $|b| \leq 0.5^\circ$ with an angular resolution of 19 arcsec, velocity resolution of 1 km s$^{-1}$, and rms $T_A^* = 0.59$ K at these resolutions, our observations unveil the complex structure of the CMZ molecular gas in improved detail. Complemented by the $^{12}$CO CHIMPS2 data, we estimate a median optical depth of $τ_{13} = 0.087$. The preliminary analysis yields a median $^{13}$CO column density range equal to $N(^{13}\text{CO})= 2$--$5 \times 10^{18}$ cm$^{-2}$, median H$_2$ column density equal to $N(\text{H}_2)= 4 \times 10^{22}$ cm$^{-2}$ to $1 \times 10^{23}$ cm$^{-2}$. We derive $N(\text{H}_2)$-based total mass estimates of $M(\text{H}_2)= 2$--$6 \times 10^7\, M_{\odot}$, in agreement with previous studies. We analyze the relationship between the integrated intensity of $^{13}$CO and the surface density of compact sources identified by Herschel Hi-GAL, and find that younger Hi-GAL sources detected at 500 $μ$m but not at 70 $μ$m follow the dense gas of the CMZ more closely than those that are bright at 70 $μ$m. The latter, actively star-forming sources, appear to be more associated with material in the foreground spiral arms.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑