II. The Universe Around Us. ASTR378 Cosmology : II. The Universe Around Us 23
|
|
- Stephany Dalton
- 5 years ago
- Views:
Transcription
1 II. The Universe Around Us ASTR378 Cosmology : II. The Universe Around Us 23
2 Some Units Used in Astronomy 1 parsec distance at which parallax angle is 1 ; 1 pc = m ( 3.26 light years; 1 kpc = m, 1 Mpc = m) 1 M = kg, 1L = W 1 Å = m (0.1 nm) 1 ev = J ASTR378 Cosmology : II. The Universe Around Us 24
3 Stars (Sun: 1 M, 1 L ) The Visible Universe Galaxies (MW: M ) Local Group (MW + M ): scale ~1 Mpc Clusters/superclusters of galaxies, voids: scale ~100 Mpc ~Smooth on larger scales... ASTR378 Cosmology : II. The Universe Around Us 25
4 Other Wavelengths of Light Microwaves: the Cosmic Microwave Background (CMB), black body spectrum corresponding to 2.7 K Radio, Infrared: can penetrate (IR can be emitted by) dust, see obscured star formation / objects at high redshift (+...) X-ray: hot gas, important for measuring the mass of galaxy clusters (+...) ASTR378 Cosmology : II. The Universe Around Us 26
5 The Cosmological Principle Considering the largest scales in the Universe, we make the following fundamental assumptions: 1) Homogeneity: On the largest scales, the Universe has the same physical properties Every region has the same physical properties (mass density, expansion rate, visible vs. dark matter, etc.) 2) Isotropy: On the largest scales, the Universe looks the same in any direction We should see the same largescale structure in any direction 3) Universality: The laws of physics are the same everywhere in the Universe ASTR378 Cosmology : II. The Universe Around Us 27
6 Homogeneity and Isotropy Cosmological principle: on large scales the Universe is homogeneous and isotropic homogeneous (Universe looks the same at each point) isotropic (Universe looks the same in all directions) but isotropic at every point = homogeneous large scales: > 100 Mpc Perfect cosmological principle: the Universe is homogeneous and isotropic in space and time Steady State Universe (not true!) CMB ASTR378 Cosmology : II. The Universe Around Us 28
7 Olbers Paradox Heinrich Olbers (1826): Why is the night sky dark? n = mean number density of stars, L = mean stellar luminosity flux at Earth: f (r) = L 4πr 2 power (unit area) -1 (steradian) -1 : total intensity of starlight: Yet the night sky is dark...? dj(r) = J = nl 4π L 4πr 2 n r2 dr r= 0 dr = ASTR378 Cosmology : II. The Universe Around Us 29
8 The Expanding Universe Blueshift Redshift z : z λ obs λ em λ em z v c (SR: 1 + z ) ( ) = 1 + v /c 1 v /c Redshift 1920 s: Hubble (and Humason) discovered a proportionality between a galaxy s redshift and its distance (Hubble Law) z = H 0 c r v = H 0 r ASTR378 Cosmology : II. The Universe Around Us 30
9 The Hubble Constant Hubble found a value for the Hubble Constant H km s -1 Mpc -1 (bad calibration!) For decades H 0 disputed (50 100); current consensus H 0 70 km s -1 Mpc -1 Outside the Local Group, virtually every galaxy is moving away from us -- why doesn t this violate the Cosmological Principle? If no acceleration/deceleration, galaxies were together at time: Original Hubble Diagram More Recent Version t 0 = r v = r H 0 r = H 1 0 H 0 70 H Gyr, (Hubble Time) c 4300Mpc (Hubble Distance, H 0 or horizon distance) ASTR378 Cosmology : II. The Universe Around Us 31
10 How can the Hubble Law be Isotropic? Three galaxies (1,2,3) in a triangular configuration, with sides r12, r23, r31 Homogeneous, uniform expansion means shape preserved expansion law of form r12(t) = a(t)r12(t0) a(t): scale factor; a = t= t0 At time t, an observer in galaxy 1 will see the other galaxies receding with velocity: dr a 1 r12 ( t ) dt a dr a v 31 (t) = 31 = a r31 ( t 0 ) = r31 ( t ) dt a v12 (t) = 12 2 = a r12 ( t 0 ) = 3 the velocity distance relation takes the linear form v = Hr, with H=å/a ASTR378 Cosmology : II. The Universe Around Us 32
11 What s the Universe Made Of? 2 E total E γ = hf = m 2 c 4 + p 2 c 2 E total = mc p2 m 2 c 2 1/ 2 Energy of a particle mc p 2 m ( hν ) Energy of a photon in the nonrelativistic limit Baryons Particle Symbol Rest Energy (MeV) Charge proton p neutron n electron e neutrino e,,?,?,? 0 photon 0 0 dark matter??? 0 ASTR378 Cosmology : II. The Universe Around Us 33
12 Sneak Peek: What is the Universe Made of? 0.6% in Stars ASTR378 Cosmology : II. The Universe Around Us 34
13 Blackbody Radiation In thermodynamic equilibrium, photons have a energy density in the frequency interval df around frequency f given by the blackbody (BB) function: ε( f )df = 8πh c 3 ε γ = αt 4, α = π 2 k B 4 f 3 df exp(hf /k B T) 1 The number density of photons is: n γ = βt 3, β = π 2 15h 3 c J m -3 K -4 k B 3 h 3 c m -3 K -3 ASTR378 Cosmology : II. The Universe Around Us 35
14 Blackbody Radiation II Peak frequency of BB distribution: f peak 2.8k B T/h Peak energy of BB distribution: E peak = hf peak 2.8k B T Mean photon energy: E mean = hf mean 2.7k B T ASTR378 Cosmology : II. The Universe Around Us 36
15 The Cosmic Microwave Background Discovered in 1965 by Penzias and Wilson, BB spectrum with T=2.725±0.001 K Big Bang vs. Steady State Once dipole (motion towards Hydra, 630 km s -1 ) and Galactic emission subtracted, extremely isotropic / homogeneous (10-5 ) Note: ~1% of the static on TV is due to the CMB! ASTR378 Cosmology : II. The Universe Around Us 37
16 How is the CMB a Relic of the Big Bang? Hot Big Bang: Early Universe very dense and very hot (T>>10 4 K) baryonic matter completely ionised, free electrons made Universe opaque to photons As Universe expanded, T ; when T~3000 K, neutral atoms formed, no longer many free electrons photons free to go So why is the CMB a 2.7 K BB, not a 3000 K BB? V a( t) 3, ε γ = αt 4, P γ = ε γ 3 dq = de + PdV, dq = 0, de dt = P ( t ) dv dt E = ε γ V = αt 4 V, P = P γ = αt 4 3 dt α 4T 3 dt V + T dv 4 = 1 dt 3 αt dv 4 dt 1 T dt dt = 1 3V ASTR378 Cosmology : II. The Universe Around Us 38 dv dt ; V a ( t ) 3 d ( dt lnt ) = d ( dt lna ) T(t) a(t) 1 The CMB was a 3000 K BB when the Universe was ~1100 smaller!
17 Looking at the Last Scattering Surface Today, at z = 0 the universe is fairly transparent At higher redshift, z (looking backward in time) the universe was denser (ρ = ρ0 (1+z)3) and hotter (T=T0 (1+z)) At z 1100, the universe was so dense that T > 3000 K At z > 1100 there is a transition: the universe becomes completely ionised and opaque to visible light the last scattering surface The universe was ~350,000 years old at z 1100 ASTR378 Cosmology : II. The Universe Around Us 39
18 Should the CMB be Smooth? There are people, planets, stars, galaxies, galaxy clusters and galaxy superclusters today, so we expect some non-uniformities (wiggles, etc.) in the CMB ASTR378 Cosmology : II. The Universe Around Us 40
19 The Cosmic Background Explorer (COBE) Objectives: Accurately measure the CMB temperature Find expected CMB fluctuations ASTR378 Cosmology : II. The Universe Around Us 41
20 Basic results from COBE ASTR378 Cosmology : II. The Universe Around Us 42
21 More Results from COBE The Earth is moving with respect to the CMB detectable Doppler shift! Earth s motion around the Sun Sun s motion around the Galaxy the Galaxy s motion w/rt other galaxies (large scale flows) Microwave emission from the Galaxy Fluctuations in the CMB ASTR378 Cosmology : II. The Universe Around Us 43
22 The CMB Today COBE (1990 s) WMAP (2000 s) ASTR378 Cosmology : II. The Universe Around Us 44
23 The Latest: Planck (2009 ) ASTR378 Cosmology : II. The Universe Around Us 45
24 Olbers Paradox Revisited What are our assumptions? Unobstructed line of sight to every star in the Universe? not true some could be blocked by foreground stars, intervening dust but still night sky should look like the surface of a star! Number density n and mean luminosity L constant w/rt r? Universe is infinitely large? (And filled with stars?) Universe is infinitely old? Flux from distant sources follows inverse square law? ASTR378 Cosmology : II. The Universe Around Us 46
Introduction and Fundamental Observations
Notes for Cosmology course, fall 2005 Introduction and Fundamental Observations Prelude Cosmology is the study of the universe taken as a whole ruthless simplification necessary (e.g. homogeneity)! Cosmology
More informationOlbers Paradox. Lecture 14: Cosmology. Resolutions of Olbers paradox. Cosmic redshift
Lecture 14: Cosmology Olbers paradox Redshift and the expansion of the Universe The Cosmological Principle Ω and the curvature of space The Big Bang model Primordial nucleosynthesis The Cosmic Microwave
More informationLecture #24: Plan. Cosmology. Expansion of the Universe Olber s Paradox Birth of our Universe
Lecture #24: Plan Cosmology Expansion of the Universe Olber s Paradox Birth of our Universe Reminder: Redshifts and the Expansion of the Universe Early 20 th century astronomers noted: Spectra from most
More informationAstronomy 114. Lecture35:TheBigBang. Martin D. Weinberg. UMass/Astronomy Department
Astronomy 114 Lecture35:TheBigBang Martin D. Weinberg weinberg@astro.umass.edu UMass/Astronomy Department A114: Lecture 35 09 May 2005 Read: Ch. 28,29 Astronomy 114 1/18 Announcements PS#8 due Monday!
More informationThe Expanding Universe
Cosmology Expanding Universe History of the Universe Cosmic Background Radiation The Cosmological Principle Cosmology and General Relativity Dark Matter and Dark Energy Primitive Cosmology If the universe
More informationCH 14 MODERN COSMOLOGY The Study of Nature, origin and evolution of the universe Does the Universe have a center and an edge? What is the evidence
CH 14 MODERN COSMOLOGY The Study of Nature, origin and evolution of the universe Does the Universe have a center and an edge? What is the evidence that the Universe began with a Big Bang? How has the Universe
More informationPhysics 133: Extragalactic Astronomy ad Cosmology
Physics 133: Extragalactic Astronomy ad Cosmology Lecture 2; January 8 2014 Previously on PHYS133 Units in astrophysics Olbers paradox The night sky is dark. Inconsistent with and eternal, static and infinite
More informationCosmology. Thornton and Rex, Ch. 16
Cosmology Thornton and Rex, Ch. 16 Expansion of the Universe 1923 - Edwin Hubble resolved Andromeda Nebula into separate stars. 1929 - Hubble compared radial velocity versus distance for 18 nearest galaxies.
More informationThe Big Bang. Olber s Paradox. Hubble s Law. Why is the night sky dark? The Universe is expanding and We cannot see an infinite Universe
The Big Bang Olber s Paradox Why is the night sky dark? The Universe is expanding and We cannot see an infinite Universe Hubble s Law v = H0 d v = recession velocity in km/sec d = distance in Mpc H 0 =
More informationTuesday: Special epochs of the universe (recombination, nucleosynthesis, inflation) Wednesday: Structure formation
Introduction to Cosmology Professor Barbara Ryden Department of Astronomy The Ohio State University ICTP Summer School on Cosmology 2016 June 6 Today: Observational evidence for the standard model of cosmology
More informationCOSMOLOGY PHYS 30392 OBSERVING THE UNIVERSE Part I Giampaolo Pisano - Jodrell Bank Centre for Astrophysics The University of Manchester - January 2013 http://www.jb.man.ac.uk/~gp/ giampaolo.pisano@manchester.ac.uk
More informationThe Cosmic Microwave Background
The Cosmic Microwave Background Class 22 Prof J. Kenney June 26, 2018 The Cosmic Microwave Background Class 22 Prof J. Kenney November 28, 2016 Cosmic star formation history inf 10 4 3 2 1 0 z Peak of
More informationChapter 17 Cosmology
Chapter 17 Cosmology Over one thousand galaxies visible The Universe on the Largest Scales No evidence of structure on a scale larger than 200 Mpc On very large scales, the universe appears to be: Homogenous
More informationCosmology & the CMB - Cosmology: Overview - Cosmic Microwave Background - Large Scale Structure (Wed) - CMB Fluctuations (Wed)
Oct 16, 2017 Cosmology & the CMB - Cosmology: Overview - Cosmic Microwave Background - Large Scale Structure (Wed) - CMB Fluctuations (Wed) Wednesday: HW#5 due History of the universe Discovery of Quasars
More informationWhat forms AGN Jets? Magnetic fields are ferociously twisted in the disk.
What forms AGN Jets? Magnetic fields are ferociously twisted in the disk. Charged particles are pulled out of the disk and accelerated like a sling-shot. Particles are bound to the magnetic fields, focussed
More informationAstronomy 422. Lecture 20: Cosmic Microwave Background
Astronomy 422 Lecture 20: Cosmic Microwave Background Key concepts: The CMB Recombination Radiation and matter eras Next time: Astro 422 Peer Review - Make sure to read all 6 proposals and send in rankings
More informationModeling the Universe A Summary
Modeling the Universe A Summary Questions to Consider 1. What does the darkness of the night sky tell us about the nature of the universe? 2. As the universe expands, what, if anything, is it expanding
More informationAstronomy 102: Stars and Galaxies Review Exam 3
October 31, 2004 Name: Astronomy 102: Stars and Galaxies Review Exam 3 Instructions: Write your answers in the space provided; indicate clearly if you continue on the back of a page. No books, notes, or
More informationModel Universe Including Pressure
Model Universe Including Pressure The conservation of mass within the expanding shell was described by R 3 ( t ) ρ ( t ) = ρ 0 We now assume an Universe filled with a fluid (dust) of uniform density ρ,
More informationTesting the Big Bang Idea
Reading: Chapter 29, Section 29.2-29.6 Third Exam: Tuesday, May 1 12:00-2:00 COURSE EVALUATIONS - please complete these online (recitation and lecture) Last time: Cosmology I - The Age of the & the Big
More informationAstronomy 102: Stars and Galaxies Sample Review Test for Examination 3
October 28, 2003 Name: Astronomy 102: Stars and Galaxies Sample Review Test for Examination 3 Do not open the test until instructed to begin. Instructions: Write your answers in the space provided. No
More informationLecture 37 Cosmology [not on exam] January 16b, 2014
1 Lecture 37 Cosmology [not on exam] January 16b, 2014 2 Structure of the Universe Does clustering of galaxies go on forever? Looked at very narrow regions of space to far distances. On large scales the
More informationChapter 18. Cosmology in the 21 st Century
Chapter 18 Cosmology in the 21 st Century Guidepost This chapter marks a watershed in our study of astronomy. Since Chapter 1, our discussion has focused on learning to understand the universe. Our outward
More informationi>clicker Quiz #14 Which of the following statements is TRUE?
i>clicker Quiz #14 Which of the following statements is TRUE? A. Hubble s discovery that most distant galaxies are receding from us tells us that we are at the center of the Universe B. The Universe started
More informationThe Cosmic Microwave Background
The Cosmic Microwave Background The Cosmic Microwave Background Key Concepts 1) The universe is filled with a Cosmic Microwave Background (CMB). 2) The microwave radiation that fills the universe is nearly
More informationCosmology. Jörn Wilms Department of Physics University of Warwick.
Cosmology Jörn Wilms Department of Physics University of Warwick http://astro.uni-tuebingen.de/~wilms/teach/cosmo Contents 2 Old Cosmology Space and Time Friedmann Equations World Models Modern Cosmology
More informationHomework 6 Name: Due Date: June 9, 2008
Homework 6 Name: Due Date: June 9, 2008 1. Where in the universe does the general expansion occur? A) everywhere in the universe, including our local space upon Earth, the solar system, our galaxy and
More informationCosmology. Assumptions in cosmology Olber s paradox Cosmology à la Newton Cosmology à la Einstein Cosmological constant Evolution of the Universe
Cosmology Assumptions in cosmology Olber s paradox Cosmology à la Newton Cosmology à la Einstein Cosmological constant Evolution of the Universe Assumptions in Cosmology Copernican principle: We do not
More informationIntroduction. How did the universe evolve to what it is today?
Cosmology 8 1 Introduction 8 2 Cosmology: science of the universe as a whole How did the universe evolve to what it is today? Based on four basic facts: The universe expands, is isotropic, and is homogeneous.
More informationCosmology: The Origin and Evolution of the Universe Chapter Twenty-Eight. Guiding Questions
Cosmology: The Origin and Evolution of the Universe Chapter Twenty-Eight Guiding Questions 1. What does the darkness of the night sky tell us about the nature of the universe? 2. As the universe expands,
More informationCOSMOLOGY The Universe what is its age and origin?
COSMOLOGY The Universe what is its age and origin? REVIEW (SUMMARY) Oppenheimer Volkhoff limit: upper limit to mass of neutron star remnant more than 1.4 M à neutron degeneracy Supernova à extremely dense
More informationGalaxy A has a redshift of 0.3. Galaxy B has a redshift of 0.6. From this information and the existence of the Hubble Law you can conclude that
Galaxy A has a redshift of 0.3. Galaxy B has a redshift of 0.6. From this information and the existence of the Hubble Law you can conclude that A) Galaxy B is two times further away than Galaxy A. B) Galaxy
More informationChapter 1 Introduction. Particle Astrophysics & Cosmology SS
Chapter 1 Introduction Particle Astrophysics & Cosmology SS 2008 1 Ptolemäus (85 165 b.c.) Kopernicus (1473 1543) Kepler (1571 1630) Newton (1643 1727) Kant (1724 1630) Herschel (1738 1822) Einstein (1917)
More informationBASICS OF COSMOLOGY Astro 2299
BASICS OF COSMOLOGY Astro 2299 We live in a ΛCDM universe that began as a hot big bang (BB) and has flat geometry. It will expand forever. Its properties (laws of physics, fundamental constants) allow
More informationAstronomy 113. Dr. Joseph E. Pesce, Ph.D. The Big Bang & Matter. Olber s Paradox. Cosmology. Olber s Paradox. Assumptions 4/20/18
Astronomy 113 Dr. Joseph E. Pesce, Ph.D. The Big Bang & Matter Cosmology ³The study of the origins, structure, and evolution of the universe ³Key moments: ²Einstein General Theory of Relativity ²Hubble
More informationAstronomy 113. Dr. Joseph E. Pesce, Ph.D Joseph E. Pesce, Ph.D.
Astronomy 113 Dr. Joseph E. Pesce, Ph.D. The Big Bang & Matter 17-2 Cosmology ³ The study of the origins, structure, and evolution of the universe ³ Key moments: ² Einstein General Theory of Relativity
More informationToday. Course Evaluations Open. Modern Cosmology. The Hot Big Bang. Age & Fate. Density and Geometry. Microwave Background
Today Modern Cosmology The Hot Big Bang Age & Fate Density and Geometry Microwave Background Course Evaluations Open Cosmology The study of the universe as a physical system Historically, people have always
More informationAstronomy 162, Week 10 Cosmology Patrick S. Osmer Spring, 2006
Astronomy 162, Week 10 Cosmology Patrick S. Osmer Spring, 2006 Information Makeup quiz Wednesday, May 31, 5-6PM, Planetarium Review Session, Monday, June 5 6PM, Planetarium Cosmology Study of the universe
More information26. Cosmology. Significance of a dark night sky. The Universe Is Expanding
26. Cosmology Significance of a dark night sky The Universe is expanding The Big Bang initiated the expanding Universe Microwave radiation evidence of the Big Bang The Universe was initially hot & opaque
More informationThe Cosmic Microwave Background
The Cosmic Microwave Background Our probe of the birth of the universe Will Handley wh260@cam.ac.uk Astrophysics Department Cavendish Laboratory University of Cambridge 20 th March 2013 Overview Light
More informationThe oldest science? One of the most rapidly evolving fields of modern research. Driven by observations and instruments
The oldest science? One of the most rapidly evolving fields of modern research. Driven by observations and instruments Intersection of physics (fundamental laws) and astronomy (contents of the universe)
More informationAstro-2: History of the Universe
Astro-2: History of the Universe Lecture 7; May 2 2013 Previously on astro-2 A scientific theory is a logically self-consistent model or framework for describing the behavior of a related set of natural
More informationCosmology. An Analogy 11/28/2010. Cosmology Study of the origin, evolution and future of the Universe
Cosmology Cosmology Study of the origin, evolution and future of the Universe Obler s Paradox If the Universe is infinite why is the sky dark at night? Newtonian Universe The Universe is infinite and unchanging
More informationPhysics 133: Extragalactic Astronomy ad Cosmology
Physics 133: Extragalactic Astronomy ad Cosmology Lecture 1; January 6 2014 Physics 133 Instructor: Prof. Tommaso Treu Lectures: MW 9:30-10:45 PHELP3519 Office hours: M 2:30 3:30 W 11:00-12:00 Broida 2015F
More informationCosmic Microwave Background
Cosmic Microwave Background Following recombination, photons that were coupled to the matter have had very little subsequent interaction with matter. Now observed as the cosmic microwave background. Arguably
More informationGalaxies 626. Lecture 3: From the CMBR to the first star
Galaxies 626 Lecture 3: From the CMBR to the first star Galaxies 626 Firstly, some very brief cosmology for background and notation: Summary: Foundations of Cosmology 1. Universe is homogenous and isotropic
More informationThe Dawn of Time - II. A Cosmos is Born
The Dawn of Time - II. A Cosmos is Born Learning Objectives! Why does Olbers paradox show the Universe began?! How does Hubble s Law tell us the age of the Universe? If Hubble s Constant is large, is the
More informationSet 1: Expansion of the Universe
Set 1: Expansion of the Universe Syllabus Course text book: Ryden, Introduction to Cosmology, 2nd edition Olber s paradox, expansion of the universe: Ch 2 Cosmic geometry, expansion rate, acceleration:
More informationDoppler Effect. Sound moving TOWARDS. Sound moving AWAY 9/22/2017. Occurs when the source of sound waves moves towards or away
Burkey- ESS QUIZ Thursday At the instant of the Big Bang, all the matter, energy, time, & space in the Universe was condensed into a single, tiny point. We call this Singularity. Doppler Effect Occurs
More informationOutline. Covers chapter 2 + half of chapter 3 in Ryden
Outline Covers chapter + half of chapter 3 in Ryden The Cosmological Principle I The cosmological principle The Cosmological Principle II Voids typically 70 Mpc across The Perfect Cosmological Principle
More informationAstronomy 210 Final. Astronomy: The Big Picture. Outline
Astronomy 210 Final This Class (Lecture 40): The Big Bang Next Class: The end HW #11 Due next Weds. Final is May 10 th. Review session: May 6 th or May 9 th? Designed to be 2 hours long 1 st half is just
More informationWhat is the evidence that Big Bang really occurred
What is the evidence that Big Bang really occurred Hubble expansion of galaxies Microwave Background Abundance of light elements but perhaps most fundamentally... Darkness of the night sky!! The very darkness
More informationChapter 29. The Hubble Expansion
Chapter 29 The Hubble Expansion The observational characteristics of the Universe coupled with theoretical interpretation to be discussed further in subsequent chapters, allow us to formulate a standard
More informationHubble's Law. H o = 71 km/s / Mpc. The further a galaxy is away, the faster it s moving away from us. V = H 0 D. Modern Data.
Cosmology Cosmology is the study of the origin and evolution of the Universe, addressing the grandest issues: How "big" is the Universe? Does it have an "edge"? What is its large-scale structure? How did
More informationAstronomy 1 Winter Lecture 24; March
Astronomy 1 Winter 2011 Lecture 24; March 7 2011 Previously on Astro-1 Introduction to special relativity Introduction to general relativity Introduction to black holes, stellar and supermassive Today..
More informationCosmology: Building the Universe.
Cosmology: Building the Universe. The term has several different meanings. We are interested in physical cosmology - the study of the origin and development of the physical universe, and all the structure
More informationOutline. The Cosmological Principle II. The Perfect Cosmological Principle. The cosmological principle. Covers chapter 2 + half of chapter 3 in Ryden
Outline Covers chapter 2 + half of chapter 3 in Ryden The Cosmological Principle I The Cosmological Principle II The cosmological principle Voids typically 70 Mpc across The Perfect Cosmological Principle
More informationAstronomy 182: Origin and Evolution of the Universe
Astronomy 182: Origin and Evolution of the Universe Prof. Josh Frieman Lecture 10 Nov. 11, 2015 Today Hot Big Bang I: Cosmic Microwave Background Assignments This week: read Hawley and Holcomb, Chapter
More informationLecture 17: the CMB and BBN
Lecture 17: the CMB and BBN As with all course material (including homework, exams), these lecture notes are not be reproduced, redistributed, or sold in any form. Peering out/back into the Universe As
More informationIB Physics - Astronomy
Solar System Our Solar System has eight planets. The picture below shows their relative sizes, but NOT their relative distances. A planet orbits the sun, and has gravitationally cleared its orbital area
More informationLecture 32: Astronomy 101
Lecture 32: Evidence for the Big Bang Astronomy 101 The Three Pillars of the Big Bang Threefundamental pieces of evidence: Expansion of the Universe: Explains Hubble s Law Primordial Nucleosynthesis: Formation
More informationA100 Exploring the Universe Big Bang Theory and the Early Universe. Martin D. Weinberg UMass Astronomy
A100 Exploring the Universe and the Martin D. Weinberg UMass Astronomy astron100-mdw@courses.umass.edu December 02, 2014 Read: Chap 23 12/04/14 slide 1 Assignment on Chaps 22 23, at the end of next week,
More informationAstronomy 122 Outline
Astronomy 122 Outline This Class (Lecture 26): The Primeval Fireball Next Class: Dark Matter & Dark Energy ICES Form!!! HW10 due Friday Hubble s Law implications An expanding Universe! Run in movie in
More informationCosmology. Big Bang and Inflation
Cosmology Big Bang and Inflation What is the Universe? Everything we can know about is part of the universe. Everything we do know about is part of the universe. Everything! The Universe is expanding If
More informationLarge Scale Structure in the Universe
Large Scale Structure in the Universe We seem to be located at the edge of a Local Supercluster, which contains dozens of clusters and groups over a 40 Mpc region. Galaxies and clusters seem to congregate
More informationAstr 102: Introduction to Astronomy. Lecture 16: Cosmic Microwave Background and other evidence for the Big Bang
Astr 102: Introduction to Astronomy Fall Quarter 2009, University of Washington, Željko Ivezić Lecture 16: Cosmic Microwave Background and other evidence for the Big Bang 1 Outline Observational Cosmology:
More informationCosmology. Chapter 18. Cosmology. Observations of the Universe. Observations of the Universe. Motion of Galaxies. Cosmology
Cosmology Chapter 18 Cosmology Cosmology is the study of the structure and evolution of the Universe as a whole How big is the Universe? What shape is it? How old is it? How did it form? What will happen
More informationLecture Outlines. Chapter 26. Astronomy Today 8th Edition Chaisson/McMillan Pearson Education, Inc.
Lecture Outlines Chapter 26 Astronomy Today 8th Edition Chaisson/McMillan Chapter 26 Cosmology Units of Chapter 26 26.1 The Universe on the Largest Scales 26.2 The Expanding Universe 26.3 The Fate of the
More informationImplications of the Hubble Law: - it is not static, unchanging - Universe had a beginning!! - could not have been expanding forever HUBBLE LAW:
Cosmology and the Evolution of the Universe Edwin Hubble, 1929: -almost all galaxies have a redshift -moving away from us -greater distance greater redshift Implications of the Hubble Law: - Universe is
More informationCosmology and the Evolution of the Universe. Implications of the Hubble Law: - Universe is changing (getting bigger!) - it is not static, unchanging
Cosmology and the Evolution of the Edwin Hubble, 1929: -almost all galaxies have a redshift -moving away from us -exceptions in Local Group -with distance measurements - found a relationship greater distance
More information6. Cosmology. (same at all points) probably true on a sufficiently large scale. The present. ~ c. ~ h Mpc (6.1)
6. 6. Cosmology 6. Cosmological Principle Assume Universe is isotropic (same in all directions) and homogeneous (same at all points) probably true on a sufficiently large scale. The present Universe has
More informationThe Big Bang Theory was first proposed in the late 1920 s. This singularity was incredibly dense and hot.
The Big Bang Theory was first proposed in the late 1920 s. It states that there was an infinitely small, infinitely dense point that contained everything that is the universe. This singularity was incredibly
More informationAstronomy 150: Killer Skies Lecture 35, April 23
Assignments: ICES available online Astronomy 150: Killer Skies Lecture 35, April 23 HW11 due next Friday: last homework! note: lowest HW score dropped but: HW11 material will be on Exam 3, so be sure to
More informationIf there is an edge to the universe, we should be able to see our way out of the woods. Olber s Paradox. This is called Olber s Paradox
Suppose the Universe were not expanding, but was in some kind of steady state. How should galaxy recession velocities correlate with distance? They should a) be directly proportional to distance. b) reverse
More informationThis week at Astro 3303
This week at Astro 3303 First, we have the in-class presentations Then I will return the test I will collect HW#5 HW#6 is posted and due next Wednesday Includes elements from the test Soon, we will get
More informationEnergy Source for Active Galactic Nuclei
Quasars Quasars are small, extremely luminous, extremely distant galactic nuclei Bright radio sources Name comes from Quasi-Stellar Radio Source, as they appeared to be stars! Can have clouds of gas near
More informationAstronomy: The Big Picture. Outline. What does Hubble s Law mean?
Last Homework is due Friday 11:50 am Honor credit need to have those papers this week! Estimated grades are posted. Does not include HW 8 or Extra Credit THE FINAL IS DECEMBER 15 th : 7-10pm! Astronomy:
More informationCosmology: The History of the Universe
Cosmology: The History of the Universe The Universe originated in an explosion called the Big Bang. Everything started out 13.7 billion years ago with zero size and infinite temperature. Since then, it
More informationAstro-2: History of the Universe
Astro-2: History of the Universe Lecture 8; May 7 2013 Previously on astro-2 Wherever we look in the sky there is a background of microwaves, the CMB. The CMB is very close to isotropic better than 0.001%
More informationChapter 26: Cosmology
Chapter 26: Cosmology Cosmology means the study of the structure and evolution of the entire universe as a whole. First of all, we need to know whether the universe has changed with time, or if it has
More informationAstro 101 Fall 2013 Lecture 12. Cosmology. T. Howard
Astro 101 Fall 2013 Lecture 12 Cosmology T. Howard Cosmology = study of the Universe as a whole? What is it like overall?? What is its history? How old is it?? What is its future?? How do we find these
More informationChapter 21 Evidence of the Big Bang. Expansion of the Universe. Big Bang Theory. Age of the Universe. Hubble s Law. Hubble s Law
Chapter 21 Evidence of the Big Bang Hubble s Law Universal recession: Slipher (1912) and Hubble found that all galaxies seem to be moving away from us: the greater the distance, the higher the redshift
More informationAstronomy Hour Exam 2 March 10, 2011 QUESTION 1: The half-life of Ra 226 (radium) is 1600 years. If you started with a sample of 100 Ra 226
Astronomy 101.003 Hour Exam 2 March 10, 2011 QUESTION 1: The half-life of Ra 226 (radium) is 1600 years. If you started with a sample of 100 Ra 226 atoms, approximately how many Ra 226 atoms would be left
More information2. OBSERVATIONAL COSMOLOGY
2. OBSERVATIONAL COSMOLOGY 1. OBSERVATIONAL PARAMETERS i. Introduction History of modern observational Cosmology ii. Cosmological Parameters The search for 2 (or more) numbers Hubble Parameter Deceleration
More informationExam 3 Astronomy 100, Section 3. Some Equations You Might Need
Exam 3 Astronomy 100, Section 3 Some Equations You Might Need modified Kepler s law: M = [a(au)]3 [p(yr)] (a is radius of the orbit, p is the rotation period. You 2 should also remember that the period
More informationClass 5 Cosmology Large-Scale Structure of the Universe What do we see? Big Bang Cosmology What model explains what we see?
Class 1 Introduction, Background History of Modern Astronomy The Night Sky, Eclipses and the Seasons Kepler's Laws Newtonian Gravity General Relativity Matter and Light Telescopes Class 2 Solar System
More informationIsland Universes. Up to 1920 s, many thought that Milky Way encompassed entire universe.
Island Universes Up to 1920 s, many thought that Milky Way encompassed entire universe. Observed three types of nebulas (clouds): - diffuse, spiral, elliptical - many were faint, indistinct - originally
More informationBrief Introduction to Cosmology
Brief Introduction to Cosmology Matias Zaldarriaga Harvard University August 2006 Basic Questions in Cosmology: How does the Universe evolve? What is the universe made off? How is matter distributed? How
More informationMODERN COSMOLOGY LECTURE FYTN08
1/43 MODERN COSMOLOGY LECTURE Lund University bijnens@thep.lu.se http://www.thep.lu.se/ bijnens Lecture Updated 2015 2/43 3/43 1 2 Some problems with a simple expanding universe 3 4 5 6 7 8 9 Credit many
More informationAssignments. Read all (secs ) of DocOnotes-cosmology. HW7 due today; accepted till Thurs. w/ 5% penalty
Assignments Read all (secs. 25-29) of DocOnotes-cosmology. HW7 due today; accepted till Thurs. w/ 5% penalty Term project due last day of class, Tues. May 17 Final Exam Thurs. May 19, 3:30 p.m. here Olber
More informationPart I: The Dawn of Time
Part I: The Dawn of Time Topics within Part I. 1. Origins of the Universe: from the Infinite to the Subatomic. 2. Planets and Meteorites: Neighbors in Space 3. Birth of the Earth and Moon: a Coupled System
More informationCosmology. Clusters of galaxies. Redshift. Late 1920 s: Hubble plots distances versus velocities of galaxies. λ λ. redshift =
Cosmology Study of the structure and origin of the universe Observational science The large-scale distribution of galaxies Looking out to extremely large distances The motions of galaxies Clusters of galaxies
More informationASTR 101 General Astronomy: Stars & Galaxies
ASTR 101 General Astronomy: Stars & Galaxies ANNOUNCEMENTS MIDTERM III: Tuesday, Nov 24 th Midterm alternate day: Fri, Nov 20th, 11am, ESS 450 At LAST: In the very Beginning BIG BANG: beginning of Time
More informationAstro 13 Galaxies & Cosmology LECTURE 4 Tues 18 Jan 2011 P. Madau. I Cosmological Principles 25m II Why is the Sky Dark? (Olber s
Astro 13 Galaxies & Cosmology LECTURE 4 Tues 18 Jan 2011 P. Madau 20m I Cosmological Principles 25m II Why is the Sky Dark? (Olber s Paradox) 10m III Break 15m IV Expanding Univ. - Hubble Constant 20m
More informationReally, really, what universe do we live in?
Really, really, what universe do we live in? Fluctuations in cosmic microwave background Origin Amplitude Spectrum Cosmic variance CMB observations and cosmological parameters COBE, balloons WMAP Parameters
More informationBig Galaxies Are Rare! Cepheid Distance Measurement. Clusters of Galaxies. The Nature of Galaxies
Big Galaxies Are Rare! Potato Chip Rule: More small things than large things Big, bright spirals are easy to see, but least common Dwarf ellipticals & irregulars are most common Faint, hard to see Mostly
More informationThe Cosmological Principle
Cosmological Models John O Byrne School of Physics University of Sydney Using diagrams and pp slides from Seeds Foundations of Astronomy and the Supernova Cosmology Project http://www-supernova.lbl.gov
More informationv = H o d Hubble s Law: Distant galaxies move away fastest Velocity (v) is proportional to Distance (d):
Hubble s Law: Distant galaxies move away fastest Velocity (v) is proportional to Distance (d): v = H o d The Hubble Constant was measured after decades of observation: H 0 = 70 km/s/mpc Velocity (km/s)
More informationOUSSEP Final Week. If we run out of time you can look at uploaded slides Pearson Education, Inc.
OUSSEP Final Week Last week hopefully read Holiday-Week 23rd November Lecture notes Hand in your Hubble Deep Field Reports today! (If not today then in my mail box @ International College.) Today we will
More informationASTR Final Examination Phil Armitage, Bruce Ferguson
ASTR 1120-001 Final Examination Phil Armitage, Bruce Ferguson FINAL EXAM MAY 6 th 2006: Closed books and notes, 1.5 hours. Please PRINT your name and student ID on the places provided on the scan sheet.
More information