Herschel : the first science highlights Special feature L etter to the E ditor Tracing the sites of obscured star formation in the Antennae galaxies with Herschel-PACS
Herschel : the first science highlights Special feature L etter to the E ditor Tracing the sites of obscured star formation in the Antennae galaxies with Herschel-PACS
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赫歇尔：首个科学亮点 特别报道 致编辑的信 利用赫歇尔-PACS 追踪触角星系中被遮蔽的恒星形成地点
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
J. Schreiber
中科院分区：
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作者：
U. Klaas;M. Nielbock;M. Haas;O. Krause;J. Schreiber
目标。对相互作用的星系进行远红外成像，甚至可以定位隐藏的星星形成地点，并测量核内和核外星星形成的相对强度。我们想在附近的银河系中找到恒星形成的地点。方法.得益于欧空局赫歇尔空间天文台机载PACS相机前所未有的清晰度和深度，首次可以通过70、100和160 μm的扫描图对FIR中的单个恒星形成结进行完整评估。我们使用团块提取光度学和SED诊断来推导与恒星形成活动相关的性质。结果PACS 70、100和160 μm的图像沿着重叠区域中两个核之间的一条弧沿着描绘了最近星星形成时的复杂结构。星爆节点的分辨率和额外的多波长数据允许分析它们的单个星星形成历史和状态。特别是，在中红外线（K1）最明亮的结，在南核以东，在尘埃加热和星星形成率，效率和密度方面表现出最高的活动。该区域的直径仅为2千秒差距，光度为10-1000 μm，与我们的银河系一样高。它在射电-远红外线光度比中显示出最大的射电辐射不足，并且缺乏X射线辐射，因此将其归类为一个非常年轻的复合体。最亮的100和160 μm发射区（K2）靠近碰撞前沿，由3个节点组成，也显示出高的星星形成密度和效率，在其最模糊的部分缺乏X射线发射，但射电-远红外光度比过大。这也表明了一个年轻的阶段，但其星际介质的条件不同。我们的研究结果提供了重要的检查点的相互作用星系的数值模拟时，建模的星星形成和恒星反馈。
Aims. FIR imaging of interacting galaxies allows locating even hidden sites of star formation and measuring of the relative strength of nuclear and extra-nuclear star formation. We want to resolve the star-forming sites in the nearby system of the Antennae. Methods. Thanks to the unprecedented sharpness and depth of the PACS camera onboard ESA’s Herschel Space Observatory, it is possible for the first time to achieve a complete assessment of individual star-forming knots in the FIR with scan maps at 70, 100, and 160 μm. We used clump extraction photometry and SED diagnostics to derive the properties related to star-forming activity. Results. The PACS 70, 100, and 160 μm maps trace the knotty structure of the most recent star formation along an arc between the two nuclei in the overlap area. The resolution of the starburst knots and additional multi-wavelength data allow their individual star formation history and state to be analysed. In particular, the brightest knot in the mid-infrared (K1), east of the southern nucleus, exhibits the highest activity by far in terms of dust heating and star formation rate, efficiency, and density. With only 2 kpc in diameter, this area has a 10–1000 μm luminosity, which is as high as that of our Milky Way. It shows the highest deficiency in radio emission in the radio-to-FIR luminosity ratio and a lack of X-ray emission, classifying it as a very young complex. The brightest 100 and 160 μm emission region (K2), which is close to the collision front and consists of 3 knots, also shows a high star formation density and efficiency and lack of X-ray emission in its most obscured part, but an excess in the radio-to-FIR luminosity ratio. This suggests a young stage, too, but different conditions in its interstellar medium. Our results provide important checkpoints for numerical simulations of interacting galaxies when modelling the star formation and stellar feedback.