Active Galaxies and Related Objects
What are Active Galactic Nuclei (AGN)?
Galaxies with a source of non-stellar emission arising in the nucleus (excessive UV, IR, radio and X-ray light) Central Black Hole accreting material from host galaxy (Lynden-Bell
Overheads for Lectures:
Large Scale Kinematics for Elliptical Galaxies Line-of-sight velocity distributions Kinematically Distinct Cores
Properties of Disk/Spiral Galaxies I The Milky Way Structur MW Bulge evidence for bar-like nature MW Bulge Age and Met
Galaxy Morphology and Environment
Main relation E's more common in clusters than field f(E) = fraction of ellipticals f(Sp) = fraction of spirals regular, symmetric cluster f(E) = 40% "ratty", asymmetric cluster f(E) = 15% (Oemler 1974) f(Sp) increases wi
Properties of Elliptical Galaxies I. Stellar Populations and the Interstellar Medium
Brightest stars are red giants and AGB stars w/ spectral type K, M Very few stars produced in the last 1 2 Gyr Stars at the center of E's have ~solar metallicity (differ
Photometric Properties of Spiral Galaxies
Bulges Luminosity profiles fit r1/4 or r1/n laws Structure appears similar to E's, except bulges are more "flattened" (though bulges can be quite different from E's dynamically) Disks Many are well-represented by
Photometric Properties of Galaxies
To measure the brightness distribution of galaxies, we must determine the surface brightness of the resolved galaxy.
-measured in magnitudes/arcsec2 ( I, B, R, etc.)
Surface brightness is magnitude within 1 square arcsec
In 1924, Edwin Hubble divided galaxies into different "classes" based on their appearance.
Why begin here? Hubble classification serves as the basic language of the field. The morphological sequence reflects a fundamental physical an
MWF 8 period (3pm to 3:50pm) Textbooks: Galactic Astronomy - Binney & Merrifield Galactic Dynamics - Binney & Tremaine Galaxies in the Universe - Sparke & Gallagher Exams - 1 mid-term and 1 final exam Homeworks - 5 homeworks will be assigned throughout th
Galaxy Luminosity Function (LF) -
- What are the relative numbers of galaxies of different luminosities? N = (L) L V N is the # of galaxies that are located in volume V with luminosities between L and L+L (L) has units # galaxies/(luminosity interval*vol
Properties of Spiral Galaxies II
Kinematics of Disks As in all spiral galaxies, everything in our Galaxy orbits around the Galactic center Differential rotation material closer to the center travels on faster orbits (takes less time to make one full orbit