PPT-Tour of the Milky Way

Vital Statistics Its our home Contains more than 200 billion stars and a mass of 10 12 suns Its almost as old as the Universe itself 137 billion years old Structure The core and spiral arms are of different . 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. 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:. Mini-University 2013. Our Milky Way . in Space and Time. Our Journey…. Where in the Galaxy Are We?. The Local Neighborhood. Top Milky Way Destinations!. The Dark Heart of the Galaxy. Formation of the Milky Way. William Herschel’s map of the Milky Way based on star counts. In the early 1800’s William Herschel, the man who discovered the planet Uranus, tried to understand the shape of the Milky Way by counting stars. He counted how many stars there were in each of dozens of different directions and then plotted the count versus direction. . Q: in order to study the spatial distribution of the thin disk (which dominates the Milky Way luminosity) surface photometry in the K band from space has been used. What is the advantage of the K band? What sort of stars give off most of their light at 2 microns. 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!. Spiral Structure. . The Astronomical Context. By the 1920’s, we knew that the once-mysterious spiral nebulae were flattened galaxies. . Our Milky . Way is . also. flattened. . Two obvious . questions arose:. 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 . Here’s the mystery story we’ll unfold…. Fuzzy blobs in the sky – new solar systems, or “galaxies”?. Observational tests. Herschel’s map of the “universe” . (what we today know as just our Galaxy). La gamme de thé MORPHEE vise toute générations recherchant le sommeil paisible tant désiré et non procuré par tout types de médicaments. Essentiellement composé de feuille de morphine, ce thé vous assurera d’un rétablissement digne d’un voyage sur . 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).