Canes Venatici II dwarf galaxy

Database links to Canes Venatici II dwarf galaxy

Galaxy Canes Venatici II dwarf galaxy
Canes-Venatici-II
AladinLite
Constellation	Hunting dogs
Position equinox :  J2000.0 , epoch : J2000.0
Right ascension	12 h 57 m 10 s
declination	34 ° 18 ′ 15 ″
Appearance
Morphological type	dSph
Brightness  (visual)	15.1 ± 0.5 mag
Angular expansion	(3.2 ± 0.6) ′
Physical data
Affiliation	Local group
distance	(490,000 ± 49,000) (522,000 ± 16,000) Lj / (150,000 ± 15,000) (160,000 ± 5,000) pc
Absolute brightness	−4.9 mag
Metallicity [Fe / H]	−2.19 ± 0.58
history
discovery	T. Sakamoto and T. Hasegawa
Discovery date	2006
Catalog names
CVn II,

The Canes Venatici II dwarf galaxy , also known as Canes Venatici II for short , is a spheroidal dwarf galaxy in the constellation of the hunting dogs . It was in the year 2006 in photographs of the screening of the Sloan Digital Sky Survey discovered. The galaxy is in a distance of about 150 k pc to our solar system and moves on our sun at a speed of 130 km / s to. It has an ellipsoidal shape with an axial ratio of about 2: 1 and a half-light radius of pc. ${\displaystyle {74_{-10}^{+14}}}$

properties

Luminosity

Canes Venatici II is one of the smallest and faintest satellite galaxies in our Milky Way . The integral luminosity, with an absolute brightness of M _V = −4.9 ^m , is roughly 8,000 times that of the sun, which is less than the brightness of a typical globular cluster . Nevertheless, the dwarf galaxy has a total mass of around 2.5 million solar masses due to a high mass-luminosity ratio of 340 . This implies a dominance by dark matter that is not untypical for this type of galaxy .

Metallicity

The star population of Canes Venatici II is composed mainly of older stars that formed more than 12 billion years ago. The metallicity of this older generation of stars is correspondingly low with [Fe / H] = −2.19 ± 0.58 , which means that it has about 150 times less heavy elements than the sun. The stars of Canes Venatici II are probably among the first stars to have formed in the universe . Currently in this galaxy no star formation can be detected, the lower measuring limit of neutral hydrogen gas is 14,000 M _☉ .

Web links

Commons : Constellation Hounds  - Collection of images, videos and audio files

Individual evidence

1. ↑ ^{a b c} SIMBAD Astronomical Database . Retrieved November 21, 2011.
2. ↑ ^{a b c d e} V. Belokurov, Zucker, DB; Evans, NW; Kleyna, JT; Koposov, S .; Hodgkin, ST; Irwin, MJ; Gilmore, G. et al .: Cats and Dogs, Hair and a Hero: A Quintet of New Milky Way Companions . In: The Astrophysical Journal . 654, No. 2, 2007, p. 897. doi : 10.1086 / 509718 .
3. ↑ ^{a b c d} N.F. Martin, De Jong, JTA; Rix, HW: A Comprehensive Maximum Likelihood Analysis of the Structural Properties of Faint Milky Way Satellites . In: The Astrophysical Journal . 684, No. 2, 2008, p. 1075. doi : 10.1086 / 590336 .
4. ↑ ^{a b} Claudia Greco, Dall'Ora, Massimo; Clementini, Gisella, et al. : On the Newly Discovered Canes Venatici II dSph Galaxy . In: The Astrophysical Journal . 675, No. 2, 2008, pp. L73-L76. arxiv : 0712.2241 . bibcode : 2008ApJ ... 675L..73G . doi : 10.1086 / 533585 .
5. ↑ T. Sakamoto, Hasegawa, T .: Discovery of a Faint Old Stellar System at 150 kpc . In: The Astrophysical Journal . 653, No. 1, 2006, pp. L29-L32. arxiv : astro-ph / 0610858 . bibcode : 2006ApJ ... 653L..29S . doi : 10.1086 / 510332 .
6. ↑ ^{a b} J. D Simon, M. Geha: The Kinematics of the Ultra-faint Milky Way Satellites: Solving the Missing Satellite Problem . In: The Astrophysical Journal . 670, 2007, p. 313. doi : 10.1086 / 521816 .
7. ↑ EN Kirby, Simon, JD; Geha, M .; Guhathakurta, P .; Frebel, A .: Uncovering Extremely Metal-Poor Stars in the Milky Way's Ultrafaint Dwarf Spheroidal Satellite Galaxies . In: The Astrophysical Journal . 685, 2008, p. L43. doi : 10.1086 / 592432 .
8. ↑ J. Grcevich, Putman, ME: HI in Local Group Dwarf Galaxies and stripping by the Galactic halo . In: The Astrophysical Journal . 696, 2009, p. 385. doi : 10.1088 / 0004-637X / 696/1/385 .