HERschel Observations of Edge-on Spirals (HEROES) - I. Far-infrared morphology and dust mass determination
HERschel Observations of Edge-on Spirals (HEROES) - I. Far-infrared morphology and dust mass determination
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赫歇尔边缘螺旋观测 (HEROES) - I. 远红外形态和尘埃质量测定
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发表时间：
2013
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通讯作者：
National Observatory of Athens
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作者：
J. Verstappen;J. Fritz;M. Baes;M. Smith;F. Allaert;S. Bianchi;J. Blommaert;G. D. Geyter;I. D. Looze;G. Gentile;K. Gordon;B. Holwerda;S. Viaene;E. M. X. S. Observatorium;Universiteit Gent;S. O. Physics;Astronomy;Cardiff University;Inaf ;Instituut voor Sterrenkunde;K. Leuven;Vakgroep Fysica en Sterrenkunde;V. U. Brussel;S. S. Institute;E. S. Agency;Estec;Institute for Astronomy;Astrophysics;Space Applications;R. Sensing;National Observatory of Athens
语境。具有突出尘埃带的边缘螺旋星系为我们提供了研究其中尘埃分布和特性的绝佳机会。 HEROES 项目的设立是为了在本次调查中观察不同波长的七个大型边缘星系样本。
目标。在第一篇论文中，我们介绍了赫歇尔观测结果，并对它们进行了定性和定量分析，并得出了远红外和亚毫米发射的一些全局特性。
方法。我们根据样本中星系的赫歇尔观测确定水平和垂直剖面并描述形态。修改后的黑体适合使用孔径光度法测量的全局通量，从而得出灰尘温度和灰尘质量。后面的值与从文献中获取的辐射传输模型得出的值进行比较。
结果。总的来说，我们的赫歇尔通量测量结果与档案值非常吻合。我们发现文献中经常使用的指数水平灰尘分布模型通常可以很好地描述观测到的水平剖面。七个星系中的三个在 5σ 水平上显示出 100 和 160 μm 处的扩展垂直发射特征，但其中两个星系可能是由于偏离了精确的边缘方向。只有对于NGC 4013这个在光学图像中已经检测到垂直延伸尘埃的星系，我们才能检测到垂直延伸的尘埃，并且推导的尺度高度与通过辐射传输模型估计的值一致。我们的分析暗示了尘埃鳞片高度与其结块程度之间的相关性，这是我们根据光学数据建模和赫歇尔数据点光谱能量分布拟合计算得出的尘埃质量之间的差异推断出来的。
Context. Edge-on spiral galaxies with prominent dust lanes provide us with an excellent opportunity to study the distribution and properties of the dust within them. The HEROES project was set up to observe a sample of seven large edge-on galaxies across various wavelengths for this investigation.
Aims. Within this first paper, we present the Herschel observations and perform a qualitative and quantitative analysis on them, and we derive some global properties of the far infrared and submillimetre emission.
Methods. We determine horizontal and vertical profiles from the Herschel observations of the galaxies in the sample and describe the morphology. Modified black-body fits to the global fluxes, measured using aperture photometry, result in dust temperatures and dust masses. The latter values are compared to those that are derived from radiative transfer models taken from the literature.
Results. On the whole, our Herschel flux measurements agree well with archival values. We find that the exponential horizontal dust distribution model often used in the literature generally provides a good description of the observed horizontal profiles. Three out of the seven galaxies show signatures of extended vertical emission at 100 and 160 μm at the 5σ level, but in two of these it is probably due to deviations from an exactly edge-on orientation. Only for NGC 4013, a galaxy in which vertically extended dust has already been detected in optical images, we can detect vertically extended dust, and the derived scaleheight agrees with the value estimated through radiative transfer modelling. Our analysis hints at a correlation between the dust scaleheight and its degree of clumpiness, which we infer from the difference between the dust masses as calculated from modelling of optical data and from fitting the spectral energy distribution of Herschel datapoints.