Bootes III dwarf galaxy

The Bootes III dwarf galaxy (also called Bootes III for short ) is a decaying dwarf galaxy in the constellation of the Bear Catcher and can still be recognized as an abundance in the galactic halo . It was in 2009 in recordings of the screening of the Sloan Digital Sky Survey discovered.

properties

Sizes

The galaxy is at a distance of 46 k pc from our solar system and is moving towards our sun at a speed of 200 km / s . It has an ellipsoidal shape with an axial ratio of about 2: 1 and a half-light radius of 400 pc. The large extent on the one hand and the irregular shape on the other hand show that Bootes III is in the transition from a gravitationally bound to a gravitationally unbound system. Because of this fact, the
mass of Bootes III is extremely difficult to estimate, since in this case the velocity dispersion does not correlate with the mass of the galaxy. Bootes III may also be the source of the Styx Current in the galactic halo, which was discovered at the same time as the galaxy.

Luminosity

Bootes III is one of the faintest satellites of our Milky Way , the integral luminosity is only 18,000 times that of the sun with M _V = −5.8 ^m , which is less than the luminosity of most globular clusters .

Metallicity

The star population of Bootes III consists mainly of older stars that formed about 12 billion years ago. The metallicity of these old stars is correspondingly low with [Fe / H] = −2.1 ± 0.2 , i.e. H. Bootes III has a 120th of heavy elements compared to our sun .

additional

Web links

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

Individual evidence

↑ SIMBAD Astronomical Database. In: Results for Bootes III. Retrieved February 13, 2010 .
↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ C. J. Grillmair: Four New Stellar Debris Streams in the Galactic Halo . In: The Astrophysical Journal . tape 693 , no. 2 , 2009, p. 1118-1127 , doi : 10.1088 / 0004-637X / 693/2/1118 , arxiv : 0811.3965 , bibcode : 2009ApJ ... 693.1118G .
↑ ^a ^b ^c ^d Jeffrey L. Carlin, Carl J. Grillmair, Ricardo R. Muñoz et al: Kinematics and Metallicities in the Boötes III Stellar Overdensity: a Disrupted Dwarf Galaxy? In: The Astrophysical Journal Letters . tape 702 , no. 1 , 2009, p. L9 – L13 , doi : 10.1088 / 0004-637X / 702/1 / L9 , arxiv : 0907.3738 , bibcode : 2009ApJ ... 702L ... 9C .

↑ ^a ^b ^c ^d ^e M. Correnti, M. Bellazzini, FR Ferraro: Red Clump stars in the Bootes III stellar system . In: Mon. Not. R. Astron. Soc. tape 397 , no. 1 , 2009, p. L26 – L30 , doi : 10.1111 / j.1745-3933.2009.00677.x , arxiv : 0904.3068 , bibcode : 2009MNRAS.397L..26C .

[simbad-1] SIMBAD Astronomical Database. In: Results for Bootes III. Retrieved February 13, 2010 .

[Grillmair2009-2] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ C. J. Grillmair: Four New Stellar Debris Streams in the Galactic Halo . In: The Astrophysical Journal . tape 693 , no. 2 , 2009, p. 1118-1127 , doi : 10.1088 / 0004-637X / 693/2/1118 , arxiv : 0811.3965 , bibcode : 2009ApJ ... 693.1118G .

[Carlin2009-3] Jeffrey L. Carlin, Carl J. Grillmair, Ricardo R. Muñoz et al: Kinematics and Metallicities in the Boötes III Stellar Overdensity: a Disrupted Dwarf Galaxy? In: The Astrophysical Journal Letters . tape 702 , no. 1 , 2009, p. L9 – L13 , doi : 10.1088 / 0004-637X / 702/1 / L9 , arxiv : 0907.3738 , bibcode : 2009ApJ ... 702L ... 9C .

[Correnti2009-4] M. Correnti, M. Bellazzini, FR Ferraro: Red Clump stars in the Bootes III stellar system . In: Mon. Not. R. Astron. Soc. tape 397 , no. 1 , 2009, p. L26 – L30 , doi : 10.1111 / j.1745-3933.2009.00677.x , arxiv : 0904.3068 , bibcode : 2009MNRAS.397L..26C .