Local Sheet
| Local Sheet | |
|---|---|
| The Local Sheet on the top view within 10 million light-years from Earth, including the Local Group and other nearby giant galaxies. A portion of the Local Sheet, the Council of Giants, on the top view within 10 million light-years from Earth, including the Local Group and other nearby giant galaxies. | |
| Observation data (Epoch J2000) | |
| Number of galaxies | 14 (giant galaxies)[1] |
| Parent structure | Local Volume[1] |
| Major axis | 33.9 Mly (10.4 Mpc)[1] |
| Minor axis | 1.52 Mly (0.465 Mpc)[1] |
| Velocity dispersion | 47 km/s[1] |
| Distance | 420,700 ly (129 kpc) (center)[1] |
| ICM temperature | 7.3×105 K[1] |
| Binding mass | 1.6×1013[1] M☉ |
| Other designations | |
| Local Street, Coma–Sculptor Cloud[1] | |
.png){kind=link}
The Local Sheet or the Coma–Sculptor Cloud is a nearby galaxy filament and an extragalactic region of space where the Milky Way, the members of the Local Group, and other galaxies share a similar peculiar velocity.[2] This region lies within a diameter of about 10.4 megaparsecs (34 million light-years; 3.2×1020 kilometres), 465 kiloparsecs (1.52 million light-years; 1.43×1019 kilometres) thick,[1] and galaxies beyond that distance show markedly different velocities.[3] The Local Group has only a relatively small peculiar velocity of 66 km⋅s−1 with respect to the Local Sheet. Typical velocity dispersion of galaxies is only 40 km⋅s−1 in the radial direction.[2] Nearly all nearby bright galaxies belong to the Local Sheet.[4] The Local Sheet is part of the Local Volume and is in the Virgo Supercluster (Local Supercluster).[1] The Local Sheet forms a wall of galaxies delineating one boundary of the Local Void.[5]
A significant component of the mean velocity of the galaxies in the Local Sheet appears as the result of the gravitational attraction of the Virgo Cluster of galaxies, resulting in a peculiar motion ~185 km⋅s−1 toward the cluster.[2] A second component is directed away from the center of the Local Void; an expanding region of space spanning an estimated 45 Mpc (150 Mly) that is only sparsely populated with galaxies.[3] This component has a velocity of 259 km⋅s−1.[2] The Local Sheet is inclined 8° from the Local Supercluster (Virgo Supercluster).[1]
The so-called Council of Giants is a ring of twelve large galaxies surrounding the Local Group in the Local Sheet, with a radius of 3.746 Mpc (12.22 Mly) and its center located at 810 kpc (2.6 Mly) away from the Sun.[1] Ten of these are spirals, while the remaining two are ellipticals. The two ellipticals (Maffei 1 and Centaurus A) lie on opposite sides of the Local Group.
| Catalog ID | Name | Constellation | Distance (Mly) | Stellar mass * |
|---|---|---|---|---|
| NGC 253 | Sculptor Galaxy | Sculptor | 11 | 10.805 |
| PGC 9892 | Maffei 1 | Cassiopeia | 11 | 10.928 |
| PGC 10217 | Maffei 2 | Cassiopeia | 11 | 10.493 |
| IC 342 | Camelopardalis | 11 | 10.302 | |
| NGC 3031 | M 81 | Ursa Major | 12 | 10.905 |
| NGC 3034 | M 82 | Ursa Major | 11 | 10.573 |
| NGC 4736 | M 94 | Canes Venatici | 15 | 10.458 |
| NGC 4826 | M 64 | Coma Berenices | 16 | 10.496 |
| NGC 5236 | M 83 | Hydra | 16 | 10.642 |
| NGC 5128 | Centaurus A | Centaurus | 11 | 11.169 |
| NGC 4945 | Centaurus | 12 | 10.528 | |
| ESO 97-G13 | Circinus Galaxy | Circinus | 14 | 10.559 |
* The mass is given as the logarithm (base unspecified) of the mass in solar masses.
Location
[edit | edit source]The Local Sheet is the co-moving part of the Coma-Sculptor Cloud,[6] which was identified and described in 1987 by astronomer Brent Tully with colleague Richard Fisher in his book The Nearby Galaxies Atlas as Cloud 14.[7] It is a huge 10 Mpc (33 Mly) prolate,[8] filament[9][10][2][8] and is mostly host to late-type galaxies, in contrast to the Virgo Cluster, in which more than half of the giant galaxies are early-type galaxies.[11]
Tully maintains that the Coma-Sculptor Cloud and the Local Sheet do not quite overlap,[2] as the Local Sheet comprises only the co-moving part of the Coma-Sculptor Cloud.[6] McCall considers the two terms synonymous, referring to one and the same region.[1]
See also
[edit | edit source]- Supergalactic coordinate system, the coordinate system taking the Local Sheet, the Supergalactic Plane, as its X–Y bases
References
[edit | edit source]- ^ a b c d e f g h i j k l m n o Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c d e f Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
Lua error in mw.title.lua at line 392: bad argument #2 to 'title.new' (unrecognized namespace name 'Portal').