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Part I: Galaxies and Active Galaxies Part II: Clusters of Galaxies and Large Scale Structures. July 26, 2004. Exploring the Interstellar Medium Debrief. What is the interstellar medium? What do we know about its number density? What do we know the temperature of the ISM?
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Part I: Galaxies and Active GalaxiesPart II: Clusters of Galaxies and Large Scale Structures July 26, 2004
Exploring the Interstellar Medium Debrief • What is the interstellar medium? • What do we know about its number density? • What do we know the temperature of the ISM? • What do we know about its heat? • What is the difference between heat and temperature? • Did you prove this?
Exploring the Interstellar Medium Debrief • What is the Local Bubble, and what are some possibilities for how it formed? • What do we know now about the event and objects in our Universe? • What else do we know? Now lets move farther out… • What is a galaxy?
Now lets move farther out… • What do we know about galaxies? • How do they evolve or form? • Why do they form? • How do we know? • Prove it! • What do our students need to know about galaxies?
Hidden Lives of Galaxies • Read the first 2 pages of the handout • Get into six groups of four • Every group must have access to a wall with a poster • Use the poster the answer the questions that are asked on the handout. (page 6)
Center of M31 has two optical nuclei M31/Andromeda • Our nearest spiral neighbor • 2 million light years away
Center of M31 M31/Chandra X-ray • Image of central part of our neighbor M31 • Bright X-ray sources are binaries with black holes or neutron stars • Central BH is very cool, 30 million Mo
Edge-on Spiral Galaxy • NGC 891 - we think our Galaxy looks like this This is an infrared composite image from KPNO
Starburst galaxies • Galaxies which are undergoing rapid phase of star formation • Supernova rate about 10 times higher • Many bright stars • Fluorescent gas clouds • GRBs are in burst region. NGC 4214 HST
Starburst Galaxy M82 • Radio map is CO which traces H • IR map shows proto-stars IR Radio
Starburst galaxy M82 • X-ray evidence for intermediate mass black hole in M82 • High supernova rate makes many smaller black holes, which may merge
Hidden Lives of Galaxies In the same groups as before… • Read page 7 • Read and follow the instructions on page 8
Hidden Lives of Galaxies Once again in your same groups… • Read page 9 • Ok now based on all of the characteristics of the different types of galaxies. Now it is your turn to match the unusual galaxies with the names on the right. (page 10) Make sure you give reasons why you choose the name. • Continue reading pages 11-12, 13,and 22.
Break • Which came first, the galaxy or its central black hole?
Active Galaxies • Now get into groups and lets talk about the GLAST Active Galaxies Poster • Discussion topics: • What is it explaining? • Why does science care? • How do these objects “fit in”? • What is the scientific evidence for these objects? • What are the of the different objects on this poster? • Similar and dissimilar characteristics?
Unified Model of AGN • All AGN are the same: central BH plus disk and jets • Differences in lines, jets, & spectra are due to different viewing angles • Also possible that BHs are being fed at different rates
Galaxies and Black Holes • Zooming in to see the central torus of an Active Galaxy. Jet Accretion disk Black Hole
Radio Lobe Galaxy Radio lobes (Q-tips) Jet Accretion Disk
Two Views of an Active Galaxy View at 90o from Jet View at an angle to jet Radio Lobe Galaxy Seyfert Galaxy
HST Seyfert Galaxy NGC 7742 • Bright nucleus • 3000 light years across • 72 million light years away Looks like a fried egg!
Centaurus A/Optical • Giant elliptical galaxy • 10 million light years away • Dark dust lane obscures the central region
Centaurus A/Radio • Double Lobe Radio Galaxy • Image shows radio lobes superposed on optical image • Central black hole must be producing radio jets and lobes
Centaurus A/X-ray • X-ray image from Chandra • Bright nucleus can be seen in center at location of black hole • Small jet to lower right ends in shocked region
Symbiotic relationship Centaurus A/IR • IR map shows a second galaxy (barred spiral) hiding inside Cen A’s dust lanes • Elliptical’s gravity helps barred spiral maintain its shape • Material funneled along the spiral's bar fuels the central black hole which powers the elliptical's radio lobes
M87 Optical • Giant elliptical galaxy • At center of Virgo cluster • Many globular clusters surround it • Little dust and gas in the galaxy • 50 million light years away
M87 Optical Jet • HST IR and UV composite • Globular clusters also seen • Note shock waves and knot patterns in jet • Bright point at central black hole
M87 Radio Jet • Central black hole is making jets • Jets are making bubbles of hot gas • Bubbles are as big as 200,000 light years • Smallest resolution VLBI image is 0.2 light years
M87 X-ray and radio • X-ray contours on radio image • High energy emission from central black hole • ROSAT X-ray data
Another view of an Active Galaxy Looking down the Jet From this view, we see the Active Galaxy emitting gamma rays and X-rays. Quasar 3C279 Blazar Galaxy
3C273 3C279 Gamma-ray Quasars • 3C 279 is a very bright, repeatedly flaring gamma-ray source, seen at MeV - TeV energies 3C273 is much brighter at optical energies
Blazar movie • Shows rotating black hole in the center of Active Galaxy, which is emitting relativistic jets of material • Blazar is a quasar that is aiming its beams directly at us
Z = 5.0 Z = 4.9 Z = 4.75 Most distant QSOs • Redshift record is now around Z=6.5 • Sloan Digital Sky Survey
Active Galaxies and Jets • What do Active Galaxies look like when viewed from different distances?
Reflection and Debrief • Now what do we know? • What are the big ideas here? • What do our students need to know? • Is there anything else we need to know? • Misconceptions (take notes)
Reflection and Debrief • What are some effective ways to teach students about galaxies? • Standards??? (take notes)
Lunch Break • Which came first the galaxy or galaxy clusters? Steal images from http://www.astro.ubc.ca/people/newbury/astro311/notes/040329c.pdf
Engage • Examine the photograph of the Hubble Deep Field and the histogram of galaxies • Fill out the worksheet
Clusters of Galaxies • Clusters of galaxies are the largest gravitationally bound systems in the universe, with sizes of a few Mpc (a Mpc is about 3 million light-years). • A typical cluster contains hundreds or thousands of galaxies • Most of the mass is in the form of a hot intracluster gas, which is is heated to high temperatures (106-108K or several keV) • Clusters are rare objects: fewer than 1 in 10 galaxies in the universe resides in clusters
Types of Galaxy Clusters • Regular clusters • concentrated central core • well-defined spherical structure • often dominated by a giant galaxy • usually quite rich, M~1015 Mo • most galaxies are elliptical or lenticular • Irregular clusters • no well-defined center • ~half the galaxies are spirals • Often contain subclusters • Probably not steady state
M87 Virgo cluster of galaxies • The Virgo cluster of galaxies is about 65 million light years away • It contains about 2500 galaxies • It is dominated by M87
Virgo Cluster • It is the nearest rich cluster of galaxies • Classification - irregular • Covers about 100o of sky or at its distance it spreads out over tens of millions of light years • Recessional velocity is about 0.3% of velocity of light • X-ray emission concentrated around individual galaxies, particularly M84 and M86 • The strong radio galaxy M87 in the Virgo cluster is also a strong source of X-rays
Virgo/ROSAT X-ray emission from Clusters • Gas in clusters of galaxies is held by mass (matter plus dark matter) • Mass of hot gas is more than 3 times the mass of the visible light galaxies in the Virgo cluster • Strongest X-rays are around M87
Cluster Formation • Formation and evolution of a galaxy cluster (from T6 group at Los Alamos) • Evolution of a Cd galaxy cluster (from John Dubinski at CITA) movies
Perseus Cluster • One of the closest galaxy clusters at a distance of 300 million light years • Part of the Perseus Pisces supercluster which is 15 degrees across and has over 1000 galaxies
Optical/La Palma Hydra Cluster • Distance of 840 million light years • Several hundred galaxies in the cluster • 35 million degree gas in center rising to 40 million in the outside • Several million light years across the gas cloud