Skupina galaxií M 81
| Skupina galaxií M81 | |
|---|---|
 Foto galaxie Messier 81 z Hubbleova vesmírného dalekohledu | |
| Pozorovací údaje (Ekvinokcium J2000,0) | |
| Rektascenze | 09h 55m 33,2s[1] |
| Deklinace | +69°03′55″[1] |
| Souhvězdí | Velká medvědice, Žirafa (UMa, Cam) |
| Vzdálenost | 12 M [1] ly |
| Fyzikální charakteristiky | |
| Počet galaxií | 34[2] |
| Hmotnost | (1,03 ± 0,17) ×1012 |
| Nejjasnější galaxie | Messier 81,[2] |
| Označení v katalozích | |
| Messier 81 Group, NGC 3031 Group, LGG 176[3] | |
Skupina galaxií M81 je skupina galaxií v Souhvězdí Velké medvědice a Žirafy, která zahrnuje velmi známé galaxie Messier 81 a Messier 82 a několik dalších galaxií s velkou plošnou jasností.[2] Přibližný střed skupiny je od Země vzdálen 3,6 Mpc, což ji činí jednou z nejbližších skupin k Místní skupině galaxií.[2] Skupina galaxií M81 tvoří spolu s dalšími blízkými skupinami Místní nadkupu galaxií (Nadkupu galaxií v Panně).[4]
Členové skupiny M81
Následující tabulka ukazuje jednotlivé členy skupiny M81, jak je zařadil I. D. Karachentsev.[2]
| Název | Typ[5] | R.A. (J2000)[5] | Dec. (J2000)[5] | Rudý posuv (km/s)[5] | Magnituda[5] |
|---|---|---|---|---|---|
| Arp's Loop | Ir | 09h 57m 32.6s | +69°17′00″ | 99 | 16,1 |
| DDO 78 | Im | 10h 26m 27.4s | +67°39′16″ | 55 ± 10 | 15,8 |
| F8D1 | dE | 09h 44m 47.1s | +67°26′19″ | 13,9 | |
| FM1 | dSph | 09h 45m 10.0s | +68°45′54″ | 17,5 | |
| HIJASS J1021+6842 | 10h 21m 00.0s | +68°42′00″ | 46 | 20 | |
| HS 117 | I | 10h 21m 25.2s | +71°06′51″ | -37 | 16,5 |
| Holmberg I | IAB(s)m | 09h 40m 32.3s | +71°10′56″ | 139 ± 0 | 13,0 |
| Holmberg II | Im | 08h 19m 05.0s | +70°43′12″ | 142 ± 1 | 11,1 |
| Holmberg IX | Im | 09h 57m 32.0s | +69°02′45″ | 46 ± 6 | 14,3 |
| IC 2574 | SAB(s)m | 10h 28m 23.5s | +68°24′44″ | 57 ± 2 | 13,2 |
| IKN | dSph | 10h 08m 05.9s | +68°23′57″ | 17,0 | |
| KKH 57 | dSph | 10h 00m 16.0s | +63°11′06″ | 18,5 | |
| Messier 81 | SA(s)ab | 09h 55m 33.2s | +69°03′55″ | -34 ± 4 | 7,9 |
| Messier 81 Dwarf A | I | 08h 23m 56.0s | +71°01′45″ | 113 ± 0 | 16,5 |
| Messier 82 | I0 | 09h 55m 52s | +69°40′47″ | 203 ± 4 | 9,3 |
| NGC 2366 | IB(s)m | 07h 28m 54.7s | +69°12′57″ | 80 ± 1 | 11,4 |
| NGC 2403 | SAB(s)cd | 07h 36m 51.4s | +65°36′09″ | 131 ± 3 | 8,9 |
| NGC 2976 | SAc pec | 09h 47m 15.5s | +67°54′59″ | 3 ± 5 | 10,8 |
| NGC 3077 | I0 pec | 10h 03m 19.1s | +68°44′02″ | 14 ± 4 | 10,6 |
| NGC 4236 | SB(s)dm | 12h 16m 42s | +69°27′45″ | 0 ± 4 | 10,1 |
| PGC 28529 | Im | 09h 53m 48.5s | +68°58′08″ | -40 | 17,1 |
| PGC 28731 | dE | 09h 57m 03.1s | +68°35′31″ | -135 ± 30 | 15,6 |
| PGC 29231 | dE | 10h 04m 41.1s | +68°15′22″ | 16,7 | |
| PGC 31286 | dSph | 10h 34m 29.8s | +66°00′30″ | 16,7 | |
| PGC 32667 | Im | 10h 52m 57.1s | +69°32′58″ | 116 ± 1 | 14,9 |
| UGC 4459 | Im | 08h 34m 07.2s | +66°10′54″ | 20 ± 0 | 14,5 |
| UGC 4483 | Im | 08h 37m 03.0s | +69°46′31″ | 156 ± 0 | 15,1 |
| UGC 5428 | Im | 10h 05m 06.4s | +66°33′32″ | -129 ± 0 | 18 |
| UGC 5442 | Im | 10h 07m 01.9s | +67°49′39″ | -18 ± 14 | 18 |
| UGC 5692 | 13.5 | 10h 30m 35.0s | +70°37′07.2″ | 56 ± 3 | 13,5 |
| UGC 6456 | Pec | 11h 27m 59.9s | +78°59′39″ | -103 ± 0 | 14,5 |
| UGC 7242 | Scd | 12h 14m 08.4s | +66°05′41″ | 68 ± 2 | 14,6 |
| UGC 8201 | Im | 13h 06m 24.9s | +67°42′25″ | 31 ± 0 | 12,8 |
| UGCA 133 | Im | 07h 34m 11.4s | +66°53′10″ | 15,6 |
Názvy použité v tabulce se liší od názvů použitých Karachentsevem. Pro snadnější odkazování byly použity názvy z katalogů NGC, IC, UGC a PGC.
Působení mezi členy skupiny
Messier 81, Messier 82 a NGC 3077 na sebe navzájem silně působí.[6] Gravitační působení strhává ze všech tří galaxií plynný vodík, který uvnitř skupiny vytváří vláknité struktury. Navíc toto působení uvrhlo část mezihvězdného plynu do galaktického středu galaxií Messier 82 a NGC 3077 a spustilo tak rychlý vznik hvězd v jádrech těchto galaxií (hvězdotvorná galaxie).[6]
Galerie obrázků
Amatérský snímek Messier 81 + 82 a NGC 3077 ze skupiny galaxií M81, složenina 33 snímků každý trval 1 minutu.
Reference
V tomto článku byl použit překlad textu z článku M81 Group na anglické Wikipedii.
- ↑ a b c POWELL, Richard. Atlas of the Universe: The M81 Group [online]. [cit. 2020-02-07]. Dostupné online. (anglicky)
- ↑ a b c d e KARACHENTSEV, I. D. The Local Group and Other Neighboring Galaxy Groups. S. 178–188. Astronomical Journal [online]. Leden 2005 [cit. 2020-02-07]. Roč. 129, čís. 1, s. 178–188. Dostupné online. arXiv:astro-ph/0410065. DOI:10.1086/426368. Bibcode:2005AJ....129..178K. (anglicky)
- ↑ GARCIA, A. General study of group membership. II - Determination of nearby groups. S. 47–90. Astronomy and Astrophysics Supplement [online]. Červenec 1993 [cit. 2020-02-07]. Roč. 100, s. 47–90. Dostupné online. Bibcode:1993A&AS..100...47G. (anglicky)
- ↑ TULLY, R. B. The Local Supercluster. Astrophysical Journal. Červen 1982, roč. 257, s. 389–422. Dostupné online [cit. 2020-02-07]. DOI:10.1086/159999. Bibcode:1982ApJ...257..389T. (anglicky)
- ↑ a b c d e NASA/IPAC Extragalactic Database: Results for Various Galaxies [online]. [cit. 2020-02-07]. Dostupné online. (anglicky)
- ↑ a b YUN, M. S.; HO, P. T. P.; LO, K. Y. A high-resolution image of atomic hydrogen in the M81 group of galaxies. Nature. Prosinec 1994, roč. 372, čís. 6506, s. 530–532. Dostupné online [cit. 2020-02-07]. DOI:10.1038/372530a0. PMID 7990925. Bibcode:1994Natur.372..530Y. (anglicky)
- ↑ The mysteries of UGC 8201 [online]. spacetelescope.org, 2015-03-09 [cit. 2020-02-07]. Dostupné online. (anglicky)
Externí odkazy
Obrázky, zvuky či videa k tématu Skupina galaxií M 81 na Wikimedia Commons - FROMMERT, Hartmut. SEDS Messier Objects Database: Messier 81 [online]. seds.org [cit. 2020-02-07]. Dostupné online. (anglicky)
- POWELL, Richard. Atlas of the Universe: The M81 Group [online]. [cit. 2020-02-07]. Dostupné online. (anglicky)
Média použitá na této stránce
The mysteries of UGC 8201.jpg
(c) ESA/Hubble, CC BY 4.0
The galaxy UGC 8201, captured here by the NASA/ESA Hubble Space Telescope, is a dwarf irregular galaxy, so called because of its small size and chaotic structure. It lies just under 15 million light-years away from us in the constellation of Draco (the Dragon). As with most dwarf galaxies it is a member of a larger group of galaxies. In this case UCG 8201 is part of the M81 galaxy group; this group is one of the closest neighbours to the Local Group of galaxies, which contains our galaxy, the Milky Way. UGC 8201 is at an important phase in its evolution. It has recently finished a long period of star formation, which had significant impact on the whole galaxy. This episode lasted for several hundred million years and produced a high number of newborn bright stars. These stars can be seen in this image as the dominating light source within the galaxy. This process also changed the distribution and amount of dust and gas in between the stars in the galaxy. Such large star formation events need extensive sources of energy to trigger them. However, compared to larger galaxies, dwarf galaxies lack such sources and they do not appear to have enough gas to produce as many new stars as they do. This raises an important unanswered question in galaxy evolution: How do relatively isolated, low-mass systems such as dwarf galaxies sustain star formation for extended periods of time? Due to its relative proximity to Earth UGC 8201 is an excellent object for research and provides an opportunity to improve our understanding of how dwarf galaxies evolve and grow.
(c) ESA/Hubble, CC BY 4.0
The galaxy UGC 8201, captured here by the NASA/ESA Hubble Space Telescope, is a dwarf irregular galaxy, so called because of its small size and chaotic structure. It lies just under 15 million light-years away from us in the constellation of Draco (the Dragon). As with most dwarf galaxies it is a member of a larger group of galaxies. In this case UCG 8201 is part of the M81 galaxy group; this group is one of the closest neighbours to the Local Group of galaxies, which contains our galaxy, the Milky Way. UGC 8201 is at an important phase in its evolution. It has recently finished a long period of star formation, which had significant impact on the whole galaxy. This episode lasted for several hundred million years and produced a high number of newborn bright stars. These stars can be seen in this image as the dominating light source within the galaxy. This process also changed the distribution and amount of dust and gas in between the stars in the galaxy. Such large star formation events need extensive sources of energy to trigger them. However, compared to larger galaxies, dwarf galaxies lack such sources and they do not appear to have enough gas to produce as many new stars as they do. This raises an important unanswered question in galaxy evolution: How do relatively isolated, low-mass systems such as dwarf galaxies sustain star formation for extended periods of time? Due to its relative proximity to Earth UGC 8201 is an excellent object for research and provides an opportunity to improve our understanding of how dwarf galaxies evolve and grow.
Messier 81 HST.jpg
The spiral galaxy Messier 81 is tilted at an oblique angle on to our line of sight, giving a "birds-eye view" of the spiral structure. The galaxy is similar to our Milky Way, but our favorable view provides a better picture of the typical architecture of spiral galaxies. Though the galaxy is 11.6 million light-years away, NASA Hubble Space Telescope's view is so sharp that it can resolve individual stars, along with open star clusters, globular star clusters, and even glowing regions of fluorescent gas.
The spiral galaxy Messier 81 is tilted at an oblique angle on to our line of sight, giving a "birds-eye view" of the spiral structure. The galaxy is similar to our Milky Way, but our favorable view provides a better picture of the typical architecture of spiral galaxies. Though the galaxy is 11.6 million light-years away, NASA Hubble Space Telescope's view is so sharp that it can resolve individual stars, along with open star clusters, globular star clusters, and even glowing regions of fluorescent gas.
M81+M82-and other galaxies.jpg
Autor: Skatebiker, Licence: CC BY-SA 4.0
Amateur picture Messier 81 + 82 and NGC 3077 all of the M81 group, 33 frames stacked of 1 minute each.
Autor: Skatebiker, Licence: CC BY-SA 4.0
Amateur picture Messier 81 + 82 and NGC 3077 all of the M81 group, 33 frames stacked of 1 minute each.