PPT-Measuring Distances to Galaxies Using

Water Vapor Megamasers Jim Braatz NRAO Measuring Distances to H 2 O Megamasers Thin ring model D a 1 k 23 Ω 4 3 a acceleration v k r 12 Ω slope of . All rights reserved This tip sheet was developed in conjunction with the Great Trays TM Partnership dap with permission by ina Ba no inda Die an and sk ey from hn al ta tool art of Io old tar le nu at in 20 Io Nu trition Proj Io De ar me of Edu atio #2 . Grades are posted on course website. Average = . 122/. 180, . s.d. . = . 29 . (Section 1). . 126/. 180, . s.d. . = 24 (Section 4). Highest . 180/. 180. Scores below 100 => “serious concerns”. Galaxies . And the Foundation of Modern Cosmology. How are the lives of galaxies connected with the history of the universe?. Hubble Deep Field. Our deepest images of the universe show a great variety of galaxies, some of them billions of light-years away. Key Ideas. Distance is the most important & most difficult quantity to measure in Astronomy. Method of Trigonometric Parallaxes. Direct geometric method of finding distances. Units of Cosmic Distance:. Introduction. Trigonometric Parallax . Spectroscopic Parallax . Cepheid Variables . Type Ia Supernovae. Tully-Fisher Relationship. Hubble’s ‘Law’ . Trigonometric Parallax. While fundamental, this method is very limited in terms of how far away one can use it. For large numbers of star, ground-based measurements of parallax do not get beyond about 20 pc, although on individual objects this can be extended to about 100 pc (with much effort). . David Roberts, Jake Cohen, & Jing Lu. Brandeis University. Lakshmi . Saripalli. & Ravi . Subrahmanyan. Raman Research Institute. 1. Radio Galaxies. X-Shaped Radio Galaxies. Cheung’s Sample. H.-W. Rix IMPRS Galaxies Course March 11, 2011. Goal:. Determine . n. *. (M. *. ,. t. age. ,[Fe. /H],. R. ). . for a population of galaxies. How many stars of what mass and metallicity . formed when and where in galaxies?. Giuseppina. . Battaglia. Instituto. de . Astrofisica. de Canarias, Tenerife. Credit. : ESO/. H.H.Heyer. Credit. : ESO/L. . Calçada. Karachentsev. et al. 2014. Individual . Red . Giant Branch . stars. 23. vs. .. 1. First spiral nebula found in 1845 by the Earl of . Rosse. . Speculated it was beyond our Galaxy.. 1920 - "Great Debate" between Shapley and Curtis on whether spiral nebulae were galaxies beyond our own. Settled in 1924 when Edwin . Science 9. Using scientific notation. Distances in space are very large. We use scientific notation to represent very large and very small numbers. The first digit is between 1 and 9. This is called the base. The Hubble Tuning-Fork Diagram. This is the traditional scheme for classifying galaxies:. Elliptical Galaxies. Elliptical galaxies. have smooth, round distributions of stars. They resemble globular clusters, except they are much larger. They . Universe. Imagine that you find a star with an unknown distance, but you notice that it has a distinctive characteristic that tells you that it is a specific type of star. And let’s imagine that all stars of that type have the same luminosity, and you happen to know the value of that luminosity. You can then estimate the distance for the star you found from the inverse square law of light:. #2 . Grades are posted on course website. Average = . 126/180, . s.d. . = . 27 (Section 1). 124/180, . s.d. . = 27 (Section 2). Highest . 174/. 180. Scores below 100 => “serious concerns”. Islands of Stars. Our goals for learning. :. How are the lives of galaxies connected with the history of the universe?. What are the three major types of galaxies?. How are galaxies grouped together?.