arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2001.11043astro-ph.GA
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棒旋星系M83中CO J=2-1/1-0比值的系统变化

Systematic Variations of CO J=2-1/1-0 Ratio in The Barred Spiral Galaxy M83

J. Koda, T. Sawada, K. Sakamoto, A. Hirota, F. Egusa, S. Boissier, D. Calzetti, J. Donovan Meyer, B. G. Elmegreen, A. Gil de Paz, N. Harada, L. C. Ho, M. I. N. … 展开作者

J. Koda, T. Sawada, K. Sakamoto, A. Hirota, F. Egusa, S. Boissier, D. Calzetti, J. Donovan Meyer, B. G. Elmegreen, A. Gil de Paz, N. Harada, L. C. Ho, M. I. N. Kobayashi, N. Kuno, S. Martin, K. Muraoka, K. Nakanishi, N. Scoville, M. Seibert, C. Vlahakis, Y. Watanabe

摘要:

我们利用ALMA的总功率阵列数据,给出了M83中CO J=2-1/1-0线比的空间变化。虽然这两条线的强度紧密相关,但其比率在整个盘上变化,盘的平均比率为0.69,并显示银河系中心和双臂螺旋图案。在高分子气体表面密度的区域中,它是高的(>0.7),但在低表面密度的区域中,其范围从低到高。该比率与FUV和IR发射的空间分布和强度相关,其中FUV的相关性最好。它与红外强度比(70/350 mic)(尘埃温度的代表)的相关性也比与红外强度的相关性更好。两者合计,这些结果表明,无论是直接或间接的联系,尘埃加热的星际辐射场和条件的GMC,即使没有有效的机制是已知的热耦合的尘埃和散装气体GMC。

英文摘要:

We present spatial variations of the CO J=2-1/1-0 line ratio in M83 using Total Power array data from ALMA. While the intensities of these two lines correlate tightly, the ratio varies over the disk, with a disk average ratio of 0.69, and shows the galactic center and a two-arm spiral pattern. It is high (>0.7) in regions of high molecular gas surface density, but ranges from low to high ratios in regions of low surface density. The ratio correlates well with the spatial distributions and intensities of FUV and IR emissions, with FUV being the best correlated. It also correlates better with the ratio of IR intensities (70/350mic), a proxy for dust temperature, than with the IR intensities. Taken together, these results suggest either a direct or indirect link between the dust heating by the interstellar radiation field and the condition of GMCs, even though no efficient mechanism is known for a thermal coupling of dust and bulk gas in GMCs.

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。

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