Galactic Center Shells and a Recurrent Starburst Model
Galactic Center Shells and a Recurrent Starburst Model
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银河中心壳和循环星暴模型
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发表时间：
2003
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通讯作者：
Y. Sofue
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作者：
Y. Sofue
通过应用滤波技术去除银河系中心弧区20厘米VLA射电图像中的直丝，我们已经表明，许多半径为5到20秒差距的同心射电壳围绕着手枪和镰刀区，我们称之为银河系中心壳（GCS）。每个壳具有10 49-50 erg量级的热能。几个CO线壳相关联，其动能的顺序为10 49-50尔格。将已确认的GCS的能量加起来，总能量为10.51尔格。GCS显示出与MSX在16-26 µm处观察到的FIR壳的良好相关性。我们提出了一个模型，在该模型中，GCSs产生的手枪地区在过去的百万年中，经常性和/或间歇性的星爆。最近的一次爆发发生在大约105年前，产生了一个内部的圆形外壳（GCS I）;一百万年前的早期爆发产生了外壳（GCS II和III），这些外壳由于与周围的ISM和Sgr A晕的相互作用而变形。我们认为，经常性的恒星爆发也发生在过去，这产生了更大规模的超壳层结构。大约百万年前的一次爆发产生了银河系中心叶，1500万年前的一次更强烈的爆发产生了北极支线。
By applying filtering techniques to remove straight filaments in the 20-cm VLA radio image of the Galactic Center Arc region, we have shown that numerous concentric radio shells of radii 5 to 20pc are surrounding the Pistol and Sickle region, which we call Galactic Center Shells (GCS). Each shell has thermal energy of the order of 10 49–50 erg. Several CO-line shells are associated, whose kinetic energies are of the order of 10 49–50 erg. Summing up the energies of recognized GCSs, the total energy amounts to ∼10 51 erg. The GCSs show an excellent correlation with the FIR shells observed at 16–26 µm with the MSX. We propose a model in which GCSs were produced by recurrent and/or intermittent starbursts in the Pistol area during the last million years. The most recent burst occurred some 10 5 years ago, producing an inner round-shaped shell (GCS I); earlier ones a million years ago produced outer shells (GCS II and III), which are more deformed by interactions with the surrounding ISM and Sgr A halo. We argue that recurrent starbursts had also occurred in the past, which produced larger scale hyper-shell structures as well. A burst some million years ago produced the Galactic Center Lobe, and a much stronger one 15 million years ago produced the North Polar Spur.