تقرير
An energetic high-velocity compact cloud: CO$-$0.31+0.11
| العنوان: | An energetic high-velocity compact cloud: CO$-$0.31+0.11 |
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| المؤلفون: | Takekawa, Shunya, Oka, Tomoharu, Tokuyama, Sekito, Tanabe, Kyosuke, Iwata, Yuhei, Tsujimoto, Shiho, Nomura, Mariko, Shibuya, Yukihiro |
| سنة النشر: | 2019 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies |
| الوصف: | We have discovered an energetic high-velocity compact cloud CO$-$0.31+0.11 in the central molecular zone of our Galaxy. CO$-$0.31+0.11 is located at a projected distance of $\sim 45$ pc from the Galactic nucleus Sgr A$^*$. It is characterized by its compact spatial appearance ($d\simeq4$ pc), extremely broad velocity width ($\Delta V > 100$ km s$^{-1}$), and high CO $J$=3$-$2/$J$=1$-$0 intensity ratio. The total gas mass and kinetic energy are estimated as approximately $10^4$ $M_\odot$ and $10^{51}$ erg, respectively. Two expanding bubble-like structures are found in our HCN $J$=1$-$0 map obtained with the Nobeyama Radio Observatory 45 m telescope. In the longitude--velocity maps, CO$-$0.31+0.11 exhibits an asymmetric V-shape. This kinematical structure can be well fitted by Keplerian motion on an eccentric orbit around a point mass of $2\times 10^5$ $M_\odot$. The enhanced CO $J$=3$-$2/$J$=1$-$0 ratio is possibly attributed to the tidal compression during the pericenter passage. The model suggests that a huge mass is packed within a radius of $r < 0.1$ pc. The huge mass, compactness and absence of luminous stellar counterparts may correspond to a signature of an intermediate-mass black hole (IMBH) inside. We propose a formation scenario of CO$-$0.31+0.11 in which a compact cloud has gravitationally interacted with an IMBH and a bipolar molecular outflow was driven by the past activity of the putative IMBH. Comment: 11 pages, 7 figures, accepted for publication in PASJ |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1093/pasj/psz027 |
| URL الوصول: | http://arxiv.org/abs/1903.08896 |
| رقم الأكسشن: | edsarx.1903.08896 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1093/pasj/psz027 |
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