PHYS 005 Lecture Notes - Lecture 10: Cosmic Distance Ladder, Supermassive Black Hole, Spiral Galaxy
5 Jul 2018
School
Department
Course
Professor
Classifying Galaxies & Distance Ladder 4/27
Pop II- exists in bulge- yellow, red color
●Globular clusters
Anything that is NOT hydrogen/helium- a metal
●Metal rich= rich in oxygen, carbon
1st person to do a classification on the galaxy- Hubble’s Classification Scheme
https://ilearn.ucr.edu/webapps/blackboard/execute/content/file?cmd=view&content_id=_3212749_
1&course_id=_268211_1 Slide 4
●Based on their form in visible
light
●TUNING FORK
○Elliptical galaxies (on the left)- E- the higher the number, the longer the galaxy
○S0- lenticulars-in the middle
○Spiral galaxies- Sa-c (on the top)
■Bulge, disk, spiral arms
○Spiral Barred galaxies- SBa-c
■On the bottom of the tuning fork
○Bottom left- irregulars
●**DOES NOT imply evolution
Spirals
●Pop II in bulge Core- SUPERMASSIVE red old stars
■Overtakes color in bulge- bulge is yellow
●Pop I in disk
○70% of the disk is dwarf red stars (dim)
○Overtaken by newly created new stars (Pop I)
●Mass 10^9-10^11 M. (lenticulars)
- 70% of our galaxies are SPIRALS- beginning of universe-not as many spirals
- Supermassive black hole in the center
- Star formation along disk
- Stars, dust gas- same pattern along center
Sa
Big bulge
Tightly wound arms
A- VERY tightly wound
●Woolly- where the other starts, when it ends
Small amt of gas in arms
Sb
Smaller bulge
LOOSER arms
Document Summary
Pop ii- exists in bulge- yellow, red color. 1st person to do a classification on the galaxy- hubble"s classification scheme https://ilearn. ucr. edu/webapps/blackboard/execute/content/file?cmd=view&content_id=_3212749_ Based on their form in visible light. Elliptical galaxies (on the left)- e- the higher the number, the longer the galaxy. On the bottom of the tuning fork. Pop ii in bulge core- supermassive red old stars. Overtakes color in bulge- bulge is yellow. 70% of the disk is dwarf red stars (dim) Overtaken by newly created new stars (pop i) 70% of our galaxies are spirals- beginning of universe-not as many spirals. Woolly- where the other starts, when it ends. Can much smaller than mw- dwarf sphericals or much bigger. Billions of times the mass of the sun. Made of metal poor pop ii stars. Spirals have to form more recently to look like that. Allow them to create new stars - bluish in color. Close to the center of our galaxies.
