Extragalactic Coordinate Grids
Extragalactic Coordinate Grids
| Group Name | 100kly, 1Mly, 10Mly, 100Mly, 1Gly, 20Gly |
| Reference | -- |
| Prepared by | Brian Abbott (AMNH/Hayden) |
| Labels | Yes |
| Files | 100kly.speck, 1Mly.speck, 10Mly.speck, 100Mly.speck, 1Gly.speck, 20Gly.speck |
| Dependencies | none |
As was the case in the Milky Way Atlas, we use grids in the Extragalactic Atlas to provide scale as well as a visual beacon for home. The nested grids in the Extragalactic Atlas are centered on the Sun (or the Milky Way Galaxy) and extend to the farthest reaches of the observable Universe.
The grids are formed with Partiview's mesh command and can be brightened or dimmed with the Alpha Slider. The grids cover these size scales:
| 100kly | This is our final scale covering the Milky Way. Reaching out to 100,000 light-years, the grid is coplanar with the disk of our Galaxy and centered on the Sun. (All grids after this are in the plane of the celestial equator, since much of the galaxy survey data are in this plane.) This grid highlights the scale of the disk, the Sun's distance from the center of the Galaxy, and reaches out to the vicinity of our nearest neighboring galaxies.
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| 1Mly | The 1 million-light-year grid is tipped with respect to the 100kly. This grid covers many of the Milky Way's satellite galaxies but not the entire Local Group.
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| 10Mly | The next order of magnitude out is the 10 million-light-year grid. It spans most of the nearby galaxies in the local data group.
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| 100Mly | The 100 million-light-year grid begins to cover the close galaxies in the 2dF and Sloan galaxy surveys.
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| 1Gly | The 1 billion-light-year grid is an intermediate step to our largest grid.
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| 20Gly | The largest grid extends to 20 billion light-years from the Sun and spans the majority of the quasars. |
© 2002-2005 American Museum of Natural History
Last Modified: 2007-12-19 by Brian Abbott