Leo I group

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The two spirals M 95 and M96 form the core of M96-subgroup

The Leo I group , also M66 / M96 group , is a group of galaxies at a distance of about 35 million light years . Like the Local Group and other neighboring galaxy groups, it is part of the Virgo Supercluster. The group is located in the sky in the constellation Leo , named from the Latin Leo . The group is divided into two sub-groups, M96 sub-group to the bright galaxies M 95 , M96 and M105 , as well as the M66 subgroup , consisting essentially of the so-called Leo triplet M65 , M66 and NGC 3628 is. Both subgroups are often listed as individual groups in the literature. Here the group according to Fouqué et al. presented as a common group.

The brightest members of the group are the visually 8.9 mag bright spiral galaxy M66 and the 9.3 mag bright spiral galaxy M96. More recent distance measurements indicate a mean distance for the group of 10.4 MPc , while other measurements indicate a somewhat greater distance. The radial velocity of the group in relation to the cosmic background radiation is 1316 km / s.

Investigations taking into account numerous newly discovered dwarf galaxies , which are distributed in the M96 subgroup over a radius of about 1.1 million light years, result in a dispersion of radial velocities of 130 km / s. These data give a virial mass of almost 7 × 10 12  M , about three times the mass of the local group. The inner area around the bright main galaxies, on the other hand, shows roughly the mass and mass-luminosity relationship of the local group.

Members

The following table lists the unique identified members of the group according to the Nearby Galaxies Catalog , Lyons Groups of Galaxies Catalog (LGG), and the lists obtained from the Nearby Optical Galaxy sample by Giuricin et al. were created. The radial velocities are heliocentric, the apparent brightnesses are indicated in the B-band (blue).

Members of the M96 subgroup
Surname Type α δ v r ( km / s ) m B
M95 SB (r) b 10 h 43 m 57.7 s 2114214+ 11 ° 42 ′ 14 ″ 778 ± 4 11.4
M96 SAB (rs) off 10 h 46 m 45.7 s 2114912+ 11 ° 49 ′ 12 ″ 897 ± 4 10.1
M105 E1 10 h 47 m 49.6 s 2123454+ 12 ° 34 ′ 54 ″ 911 ± 2 10.2
NGC 3299 SAB (s) dm 10 h 36 m 23.8 s 2124227+ 12 ° 42 ′ 27 ″ 641 ± 6 13.3
NGC 3377 E5.5 10 h 47 m 42.4 s 2135908+ 13 ° 59 ′ 08 ″ 665 ± 2 11.2
NGC 3384 SB (s) 0 10 h 48 m 16.9 s 2123746+ 12 ° 37 ′ 46 ″ 704 ± 2 10.9
NGC 3412 SB (s) 0 10 h 50 m 53.3 s 2132444+ 13 ° 24 ′ 44 ″ 841 ± 2 11.5
NGC 3489 SAB (rs) 0 11 h 00 m 18.6 s 2135404+ 13 ° 54 ′ 04 ″ 677 ± 2 11.1
Members of the M66 subgroup
Surname Type α δ v r ( km / s ) m B
M65 SAB (rs) a 11 h 18 m 56.0 s 2130532+ 13 ° 05 ′ 32 ″ 807 ± 3 10.3
M66 SAB (s) b 11 h 20 m 15.0 s 2125930+ 12 ° 59 ′ 30 ″ 727 ± 3 9.7
NGC 3628 SAb pec 11 h 20 m 17.0 s 2133523+ 13 ° 35 ′ 23 ″ 843 ± 1 10.2

In addition, NGC 3384 , NGC 3593 , NGC 3628 and IC 2768 are sometimes counted as group members.

Individual evidence

  1. ^ RB Tully: The Local Supercluster . In: Astrophysical Journal . 257, 1982, pp. 389-422. bibcode : 1982ApJ ... 257..389T . doi : 10.1086 / 159999 .
  2. P. Fouque, E. Gourgoulhon, P. Chamaraux, G. Paturel: Groups of galaxies within 80 Mpc. II - The catalog of groups and group members . In: Astronomy and Astrophysics Supplement . 93, 1992, pp. 211-233. bibcode : 1992A & AS ... 93..211F .
  3. a b Karachentsev, I .; Karachentseva, V .: New dwarf galaxy candidates in the Leo-I Group . In: Astronomy Reports . 48, No. 2, 2004, pp. 267-274. doi : 10.1134 / 1.1704672 .
  4. a b NASA / IPAC Extragalactic Database . In: NED Results for Leo I Group . Retrieved October 11, 2011.
  5. RB Tully: Nearby Galaxies Catalog . Cambridge University Press, Cambridge 1988, ISBN 0-521-35299-1 .
  6. ^ A. Garcia: General study of group membership. II - Determination of nearby groups . In: Astronomy and Astrophysics Supplement . 100, 1993, pp. 47-90. bibcode : 1993A & AS..100 ... 47G .
  7. G. Giuricin, C. Marinoni, L. Ceriani, A. Pisani: Nearby Optical Galaxies: Selection of the Sample and Identification of Groups . In: Astrophysical Journal . 543, No. 1, 2000, pp. 178-194. arxiv : astro-ph / 0001140 . bibcode : 2000ApJ ... 543..178G . doi : 10.1086 / 317070 .
  8. a b c d e f g h i j NASA / IPAC Extragalactic Database . In: Results for various galaxies . Retrieved November 6, 2006.