Trio Leo
影像板權與提供: Daniel Verschatse (Antilhue Observatory)
Explanation:
This popular group is famous as the Leo Triplet - a gathering of three magnificent galaxies in one field of view. Crowd pleasers when imaged with even modest telescopes, these galaxies can be introduced individually as NGC 3628 (top), M66 (bottom left), and M65 (bottom right). All three are large spiral galaxies. They tend to look dissimilar because their galactic disks are tilted at different angles to our line of sight. NGC 3628 is seen edge-on, with obscuring dust lanes cutting across the plane of the galaxy, while the disks of M66 and M65 are both inclined enough to show off their spiral structure. Gravitational interactions between galaxies in the group have also left telltale signs, including the warped and inflated disk of NGC 3628 and the drawn out spiral arms of M66. This gorgeous deep view of the region spans about one degree (two full moons) on the sky. The field covers over 500 thousand light-years at the trio's estimated distance of 30 million light-years.
說明:
這群星系是著名的獅子三重星系 (Leo Triplet)，三個壯麗的星系聚在單一個望遠鏡視野裡，就是透過中等口徑的望遠鏡觀賞，還是一組很受歡迎的天體。個別的名稱為NGC 3628 (上)、M66 (左下)、和M65 (右下)的這組星系，全部都是大型的螺旋星系。它們看起來外觀會不同，是因為它們盤面和我們視線所夾的角度不同所致。其中，NGC 3628是側視，塵埃帶切過星系的盤面，而M66和M65的視傾角都很大，所以我們能看見它們漩渦臂結構。這組星系之間的重力作用造成了一些明顯的效應，其中包括NGC 3628 扭曲且膨脹的星系盤，以及M66被拉長的漩渦臂。這幅壯麗深空影像所涵蓋的天區大約是一度，或者說是滿月寬度的二倍。據估計，這群星系離我們約有三千萬光年遠，所以影像涵蓋了大約50萬光年的範圍。
資料來源: Scientific American
Department of Physics, NCKU
