File:NGC 6745.jpg

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Summary

Description A Bird's eye view of a Galaxy Collision
What appears as a bird's head, leaning over to snatch up a tasty meal, is a striking example of a galaxy collision in NGC 6745. A large spiral galaxy, with its nucleus still intact, peers at the smaller passing galaxy (nearly out of the field of view at lower right), while a bright blue beak and bright whitish-blue top feathers show the distinct path taken during the smaller galaxy's journey. These galaxies did not merely interact gravitationally as they passed one another, they actually collided. When galaxies collide, the stars that normally comprise the major portion of the luminous mass of each of the two galaxies will almost never collide with each other, but will pass rather freely between each other with little damage. This occurs because the physical size of individual stars is tiny compared to their typical separations, making the chance of physical encounter relatively small. In our own Milky Way galaxy, the space between our Sun and our nearest stellar neighbor, Proxima Centauri (part of the Alpha Centauri triple system), is a vast 4.3 light-years. However, the situation is quite different for the interstellar media in the above two galaxies - material consisting largely of clouds of atomic and molecular gases and of tiny particles of matter and dust, strongly coupled to the gas. Wherever the interstellar clouds of the two galaxies collide, they do not freely move past each other without interruption but, rather, suffer a damaging collision. High relative velocities cause ram pressures at the surface of contact between the interacting interstellar clouds. This pressure, in turn, produces material densities sufficiently extreme as to trigger star formation through gravitational collapse. The hot blue stars in this image are evidence of this star formation. This image was created by the Hubble Heritage Team using NASA Hubble Space Telescope archive data taken with the Wide Field Planetary Camera 2 in March 1996. Members of the science team, which include Roger Lynds (KPNO/NOAO) and Earl J. O'Neil, Jr. (Steward Obs.), used infrared, red, visual and ultravoilet filters to image this galaxy system. Lynds and O'Neil are currently using the Hubble data along with ground-based radio observations to further study the interactions within NGC 6745. Image Credit: NASA and The Hubble Heritage Team (STScI/AURA) Acknowledgment: Roger Lynds (KPNO/NOAO)
Date
Source The Goddard Library
Author NASA Goddard Space Flight Center NASA-GSFC
This image or video was catalogued by Goddard Space Flight Center of the United States National Aeronautics and Space Administration (NASA) under Photo ID: GL-2002-001105.

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Public domain
This file is in the public domain because it was created by NASA and ESA. NASA Hubble material (and ESA Hubble material prior to 2009) is copyright-free and may be freely used as in the public domain without fee, on the condition that only NASA, STScI, and/or ESA is credited as the source of the material. This license does not apply if ESA material created after 2008 or source material from other organizations is in use.

The material was created for NASA by Space Telescope Science Institute under Contract NAS5-26555, or for ESA by the Hubble European Space Agency Information Centre. Copyright statement at hubblesite.org or 2008 copyright statement at spacetelescope.org.

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  • 2006-02-06 00:35 Ryanrs 755×726×8 (528025 bytes) [http://library01.gsfc.nasa.gov/search/images/imageslist.php?id=115&searchterm=everything&searchfield=entire NASA Goddard Library]
  • 2005-09-25 23:18 Hurricane Devon 500×481×8 (13644 bytes)

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7 November 2002

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current05:01, 31 May 2007Thumbnail for version as of 05:01, 31 May 2007755 × 726 (516 KB)Spyder Monkey{{Information |Description=''no original description'' |Source=Originally from [http://en.wikipedia.org en.wikipedia]; description page is/was [http://en.wikipedia.org/w/index.php?title=Image:NGC_6745.jpg here]. |Date=2005-09-25 (first version); 2006-02

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