AST 248 Lecture Notes - Lecture 5: Barred Spiral Galaxy, Galactic Center, Virgo Cluster

• School: Stony Brook University
• Department: Astronomy
• Course: AST 248
• Professor: James Lattimer

Document Summary

Galaxies are self-gravitating systems with up to a trillions stars and diameters of 10 25 kpc. The observed universe has billions of galaxies; our galaxy is known as the milky way. It"s u(cid:374)k(cid:374)o(cid:449)(cid:374) if gala(cid:454)ies e(cid:448)ol(cid:448)ed fro(cid:373) o(cid:374)e (cid:272)lass i(cid:374)to another. Gala(cid:454)ies are(cid:374)"t ra(cid:374)do(cid:373)l(cid:455) distri(cid:271)uted (cid:271)ut te(cid:374)d to (cid:272)luster. Cluster sizes ra(cid:374)ge fro(cid:373) a fe(cid:449) doze(cid:374) members, as in our local group, to 10,000 like the virgo cluster. Galaxies began forming 12. 5 gyr ago when the universe was 1 gyr old. The milky way has consumed several nearby dwarf galaxies; the magellanic clouds will be consumed in the near future. The milky way is a barred spiral galaxy with 2 4 1011 stars, 6 1011 m of stars and gas and 30 . Major components include the nucleus (bulge), halo and disk (spiral arms. ) The galactic center, as do most galaxies, contains a supermassive black hole (3 106 m , called.