PPT-The Milky Way

Galaxy part 2 Unit Galaxies Star systems like our Milky Way Contain a few thousand to tens of billions of stars Large variety of shapes and sizes Galaxy Diversity The Hubble Deep Field. Lec21: The Milky Way The Milky Way GalaxyLecture 21APOD Lec21: The Milky WayAtomic, molecular, and ionized gas Lec. 21: The Milky Way21 -2 Lec21: The Milky Way Recap. Canvas homework: due on Wednesday. Lab this week: Galaxy Morphology. Campus Observatory. Milky Way galaxy. Stars: . brightnesses. , masses, sizes, compositions, evolution. Interstellar matter: gas, dust. Paul McMillan. Surveys For All, 1st February 2016 . Why do we care?. On the biggest scales, the ΛCDM model works. Why do we care?. On the scale of individual galaxies, agreement is less obvious.. Things are more complicated, we have to consider the baryons. The Milky Way: Our Home Galaxy. What are the different. components of the Milky Way?. How do we see those components?. What does a map of each component look like from our point of view?. Stars in the Milky Way. M51 – A typical spiral-disk galaxy. The M81 group of galaxies. M82. M81. Satellite galaxy. Satellite galaxy. M81 group showing hydrogen emission at radio wavelengths. Composite image of M 81. Blue shows X-Ray observations(high energy), pink infrared (dust). . Loners. Interactions were once . believed to be unimportant . and rare.. Galaxies were thought to . be . isolated loners. , well . separated from one . another . a. nd scarcely interacting.. Au Contraire!. Our Place Within It. . . The Visible Milky Way. The Milky Way as Seen From Texas. (from Canada, we can. ’. t see the Southern Cross). The Obvious Questions. How big is the Milky Way, and where are we located? At the . The Greek philosopher Democritus (450–370 BC) proposed that the bright band on the night sky known as the Milky Way might consist of distant stars. Aristotle (384–322 BC), however, believed the Milky Way to be caused by "the ignition of the fiery exhalation of some stars which were large, numerous and close together" and that the "ignition takes place in the upper part of the atmosphere, in the region of the world which is continuous with the heavenly motions.“ The . Galaxies (part I) . T. Howard. The Galaxy – part I -- Overview. New distance unit: the . parsec. (pc).. Using Earth-orbit parallax, if a star has a . parallactic. angle of 1",. it is 1 pc away. . Now what country…. W. hat continent…. W. hat planet…. W. hat galaxy?. After today’s lesson, you should be able to answer all of these questions and more!. How is our solar system positioned in the milky way galaxy and the universe?. Chapter . 13, . Sections . 1. -5,7 (12 . pages). Homework for Next Time: . www.galaxyzoo.org. Question. Which of these is a picture of the Milky Way?. A. B. D. C. The Milky Way. Angular Size. Andromeda: MW’s Sister Galaxy. Neoplatonist. philosopher . Olympiodorus. the Younger (c. 495–570 AD) criticized this view, arguing that if the Milky Way were sublunary it should appear different at different times and places on the Earth, and that it should have parallax, which it does not. In his view, the Milky Way was celestial. This idea would be influential later in the Islamic world.. The astonishing variety of galaxies derived from a few structural types. Sec 1.3. Irregulars. = misfits in any class. Edwin Hubble . The Realm of the Nebulae . (1936. ). ‘. Tuning Fork’ classification scheme of galaxies. David Spergel. What has changed?. Context:. Standard cosmological model. No galaxy is an island… (John Dunne vs. Immanuel Kant). Tools:. Statistical galactic astronomy. 100s of stars -> 100,000s -> 1e9 (GAIA +LSST).