Details Title: CHAPTER 16 Description: from book and outline paper Total Flash Cards: 33 Created: 05/05/2009 16:29:30		New Users: To study from this flashcard set, or to create your own your own study flash cards, REGISTER HERE. Existing Users: CLICK HERE. Additional Astronomy Flashcards
Cards in this set: Term how many stars do galaxies consist of? Definition a few thousand to tens of billions Term What is the Hubble Deep Field an image of? Definition thousands of distant galaxies Term What is the shape of EO galaxies? E7 galaxies? Definition EO are spherical, E7 are highly elliptical Term What type of nucleus does an Sa galaxy have? Sc? Definition Sa nucleus is large, Sc is small nucleus Term Sa galaxies have what kind of arms? Sc? Definition Sa have tightly wound arms Sc have loose arms Term A galaxy with a disk and a bulge but with no gas is classified as? Definition S0 Term What are spiral galaxies with a bar in the center called? Definition barred spiral galaxies Term What are three types of irregular galaxies? Definition 1. starburst galaxies 2. dwarf galaxies Term what do standard candles tell us? when compared to apparent magnitude, what do they help us find? Definition the absolute magnitude, distance Term what do we use to measure the distances of the farthest galaxies? Definition hubble law Term what two things can we study to determine the mass of a galaxy? Definition rotation curves and keplers 3rd law Term Most galaxies have what in the center? Definition black holes Term Most of the mass in a galaxy is visible or invisible? Definition invisible Term what three are the visible mass in the galaxy? Definition stars, interstellar gas, and dust Term what is the invisible mass made up of? Definition brown dwarves, small black holes, elemetary particles Term What is one method of detecting dark matter? Definition by observing gravitational lensing Term true or false. Galaxies exist in isolation. Definition false Term How many galaxies do rich clusters usually have? Are they or are they not centered on a large galaxy? Definition more than 1000 and are centered on a large galaxy Term How many galaxies do poor clusters usually have? Are they or are they not centered around large galaxies? Definition are not centered around large galaxies and less than 1000 Term what is our galaxy cluster called? Definition the local group Term what is the milky way currently ripping apart? Definition the Canis Major Dwarf galaxy Term what three objects do we observe when galaxies collide or interact? Definition 1. ring galaxies 2. tidal tails 3. starburst galaxies Term what is the evidence of the collision of galaxies NGC 7252? Definition evidence of mergers of galaxies Term what is the multiple nuclei in giant elliptical galaxies evidence of? Definition merger of galaxies Term what are starburst galaxies? Definition galaxies where stars are being born at a high rate Term what do galaxies look like through 19th century telescopes? Definition spiral nebulae Term what three classes are galaxies divided into? Definition elliptical, sprial and irregular Term Elliptical galaxies can't make new what? Definition stars Term What measurement do astronomers use to measure distances? Definition megaparsacs Term What is hubble law? Definition the apparent velocity of recession of galaxy equals the distance times the hubble constant V=DxHC Term what does the rotation curve of a galaxy show? Definition the orbital motion of its stars Term What term describes how larger galaxies can absorb smaller galaxies? Definition galactic cannablism Term how are ring galaxies produced? Definition by high-speed collisions where small galaxy plunges through larger galaxy perpendicular to disk