1. Introduction to Astronomy to see the levels of structure in our universe to see the levels of structure in our universe to get some sense about the physical nature of various objects to get some sense about the physical nature of various objects to see how we explore the universe. to see how we explore the universe.

2. Astronomy vs. Astrology Astro-nomy means the “naming” of the stars, but today refers to the study of celestial objects. Astro-nomy means the “naming” of the stars, but today refers to the study of celestial objects. Astro-logy means the study of stars, but today refers to how patterns among the stars may related to the course of human events. Astro-logy means the study of stars, but today refers to how patterns among the stars may related to the course of human events.

3. The Scientific Method Recognize Patterns Collect Data Predict New Observations Form Hypothesis

4. Scales of the Universe

5. The speed of light: c = 3x10 5 km/s. Source Distance (km) Light Travel time London 6,000 0.02 s Moon 385,000 1.3 s Sun1.5 x 10 8 500 s (8.3 min) Jupiter7.8 x 10 8 43 min Nearest Star4 x 10 13 4.3 years Most Distant Galaxy1.4 x 10 23 14 billion years Whenever you see "light-(time)", that means we are talking about distance, not time.

6. The finite speed of light lets us “look” into the past! 11,000 l-years Earth Supernova now 8993 BC Consider this: If you had friends throughout the galaxy, how could you create a “live” TV show of the past?

7. Survey Question Sound travels at a speed of 300 meters per second. In analogy to the light-year, what does 1 sound-minute equal? The time sound takes to travel 300 meters. The time delay of a sound heard 300 meters away. The distance traveled by sound in 1 minute. The speed of sound 1 minute later.

8. Survey Question If the Universe is infinite in size and 14 billion years old, the most distant object that we could ever hope to see is: 1) 100,000 light-years away 2) 14 billion light-years away 3) 14 billion years away 4) there is no limit – if we look hard enough, we will see all objects.

9. A Sense of Space 1. The Sun would hold 1.3 million Earths. 2. There are ~100 billion "Suns" in a galaxy like our own Milky Way Galaxy. 3.Astronomers can see billions of galaxies.

11. Various motions of the Earth, Moon, and Sun

12. The Birth, Life and Death of Stars

13. How can we learn about the lives of stars when little changes except on timescales much longer than all of human history? Suppose you had never seen a tree before, and you were given one minute in a forest to determine the life cycle of trees. Could you piece together the story without ever seeing a tree grow? This is about the equivalent of a human lifetime to the lifetime of the Sun.

14. Stellar “Forest”

15. Supernova 1987a before/after

17. The Milky Way How do we know where we are in a galaxy? How do we know that we are not at the center of the Galaxy What is the shape of the Milky Way galaxy? What are in the Galaxy?

18. A Forest of Stars, Gas, and Dust The colors in the Milky Way reveal much about what’s going on physically. However there can be several explanations for the same color—so more detailed analysis is required to understand it

19. Kinds of Nebulae Emission & Reflection Nebula Globular ClusterOpen Cluster Dark Nebula Planetary Nebula Spiral Nebula

20. Galaxies What is a “standard candle”? Why is it useful? What is a “standard candle”? Why is it useful? What are the basic types of galaxies? What are the basic types of galaxies? What holds them together? What holds them together? How did they form? How did they form? How do they evolve? How do they evolve?

21. The Andromeda Galaxy About 2 million light years away. Angular size (about 2 degrees) ---> the size of the Milky Way. Another island universe!

22. The Local Group D~50 kpc R~2kpc ~3 dozen D~700 kpc R~20 kpc D~700 kpc R~5 kpc

23. Galaxy Clusters Coma cluster In a typical cluster of galaxies, the galaxies orbit at over 1000 km/sec. From Newton’s laws one can determine how much mass must be present to prevent the cluster from dissolving.

24. ~1000 galaxies in 1 arcmin 2 The whole sky is ~ 10 8 larger! ~100 billion galaxies in whole sky currently detectable! Virtually every speck in this image is a galaxy! Hubble Deep Field

25. Cosmology Cosmology is the study of the origin and the development of the Universe, addressing the grandest issues: Does it have an "edge"? Does it have an "edge"? Does it have a center Does it have a center How does it look like on How does it look like on large scales (> 300 ly) ? How did it start? How did it start? How old is it? How old is it? How long will it live? How long will it live?

26. The Evolving Universe Cosmological Simulations Observational Cosmology

27. Formation of the Large-Scale Structure Klypin, Kravtsov, Gottlöber Dark Matter Simulation

28. A Sense of Time If we were to compress the time since the Big Bang into one year, and make the time of the Big Bang January 1,  The Earth was formed in mid-September.  The mammals appeared on December 26.  All human prehistory (from the first known stone tools) and history have occurred in the last ½ hour of New Year's Eve. All of human history is but a fleeting instant on the cosmic timescale.

30. Astronomy Colloquium talk: Quenching of star formation in massive galaxies Place: LGRT 1033 Time: 4:00PM (this Thursday) Kate Whitaker

31. Guest presentation: LMT Science and Instrumentation Next Monday Prof. Gopal Narayanan

32. Please finish the Observatory Visit Assignment (due Oct. 15). Please start to read articles for the team project/discussion assignment.

36. Large Millimeter Telescope

40. The Symphony of Light Radio infrared X-ray optical

41. Optical Sky

42. Near-infrared sky Boldt et al.

43. Radio Sky

44. Soft X-ray Sky

45. Gamma-ray all-sky map Fermi Gamma-ray Space Telescope

46. Observational Astronomy at UMass

47. How does the Hubble Sequence form? Stars very old, formed at z>2 (25% of the cosmic time) Still forming stars “Early Types”, spheroidal systems, pressure supported(velocity dispersion) σ≈250 km/s for M≈10 12 M  (1 M  = 2x10 30 kg) “Late Types”, disk systems (spiral galaxies), rotationally supported v rot ≈250 km/s for M≈10 12 M 

48. Daniela Calzetti’s Science Daniela’s science interests are in the field of star formation, as garnered from galaxies outside our Milky Way. The process of star formation tells us how gas in the Universe is converted into stars, thus transforming darkness into light, and providing a path for the evolution of galaxies across cosmic times. Her science requires data across the electromagnetic spectrum. She is working on projects that have some of the largest time allocations on major facilities, including the newly launched ESA/Herschel Space Telescope and the Hubble Space Telescope. M82

49. Question: how do galaxies, with their complicated inflows, outflows, etc., evolve?

50. QSO Absorption Spectroscopy

51. Galaxies and SMBH Mass of a galaxy’s central black hole is closely related to mass of its bulge Mass of a galaxy’s central black hole is closely related to mass of its bulge Development of central black hole must be somehow related to galaxy evolution Development of central black hole must be somehow related to galaxy evolution Magorrian, Ferrarese, Merritt, etc.

52. Red: 1-2.5 keV Green: 2.5-4 keV Blue: 4-9 keV Wang et al. 2002

53. M BH =4x10 6 M  M BH =4x10 6 M  L x = 3x10 33 erg/s, L x = 3x10 33 erg/s, or ~ 10 -11 L E or ~ 10 -11 L E L bol = a few x10 36 erg/s, mostly in radio to submm. L bol = a few x10 36 erg/s, mostly in radio to submm. What is the mode of the accretion, and what determines the luminosity? What is the mode of the accretion, and what determines the luminosity? If we have answers to these questions, we may understand a large class of ultra-dim galactic nuclei. If we have answers to these questions, we may understand a large class of ultra-dim galactic nuclei. Sgr A*

54. Temporal decomposition of the Sgr A* X-ray data Detected flares account for ~1/3 of the total X-ray flux of Sgr A* (J. Neilsen et al. 2013). No sign of line emission in detected flare spectrum. Quiescent emission

55. X-ray emission line spectroscopy halo

56. HD simulations of stellar winds around Sgr A* Cuadra et al 2006

58. Shadow and light-bending of black holes

59. Feedback Source: Old Stars 0.5-1 keV 1-2 keV 2-8 keV IRAC 8 micro K-band 0.5-2 keV Li & Wang 2007 Lx~2x10 38 erg/s Such gentle, long-lasting outflows can effectively affect the ecosystem (Tang et al. 2009).

60. Diffuse hot gas in the bulge of M31 Tang, Wang, MacLow, & Joung 2009

61. Galactic coronae: examples Li & Wang 2012

62. Determining the role of cosmic- ray/magnetic field in regulating outflows Based on a 2-hr C-array 1.5 GHz JVLA test observation (Irwin et al. 2012).

63. Feedback Source: Massive Stars Red - X-ray Green – H  Blue – Far-UV/optical 30 Doradus nebula (Wang 1999)LMC N11 Is the expansion driven mainly by radiation or mechanical energy? What fraction of the energy is consumed locally? What fraction can escape into galactic halos?