Large scale galaxy surveys

Public talk given at the Astronomical Society of New South Wales, 14th June 2013

Transcript

1. Large Scale Galaxy Surveys James Allen ASNSW - 14th June 2013
2. Image: POSS/DSS
3. Astronomy is a data-rich science Image: POSS/DSS
4. Surveys are often limited by our ability to store, process and analyse that data Astronomy is a data-rich science Image: POSS/DSS
5. Why do surveys?
6. Why do surveys? Image: Toby Gray
7. Why do surveys? Image: Toby Gray Image: Doug88888 (flickr) Image: ihasb33r (flickr) Image: Hannibal Poenaru (flickr) Image: elycefeliz (flickr)
8. Why do surveys? Image: Toby Gray Image: Doug88888 (flickr) Image: ihasb33r (flickr) Image: Hannibal Poenaru (flickr) Image: elycefeliz (flickr) Image: Mikey G Ottowa (flickr) Image: Uriel 1998 (flickr) Image: MowT (flickr) Image: Lab2112 (flickr) Image: Moyan_Brenn (flickr) Image: admiller (flickr) Image: Tjflex2 (flickr)
9. Why do surveys? Surveys tell us about the population Image: Toby Gray Image: Doug88888 (flickr) Image: ihasb33r (flickr) Image: Hannibal Poenaru (flickr) Image: elycefeliz (flickr) Image: Mikey G Ottowa (flickr) Image: Uriel 1998 (flickr) Image: MowT (flickr) Image: Lab2112 (flickr) Image: Moyan_Brenn (flickr) Image: admiller (flickr) Image: Tjflex2 (flickr)
10. Why do surveys? Surveys tell us about the population Image: Toby Gray Image: Doug88888 (flickr) Image: ihasb33r (flickr) Image: Hannibal Poenaru (flickr) Image: elycefeliz (flickr) Image: Mikey G Ottowa (flickr) Image: Uriel 1998 (flickr) Image: MowT (flickr) Image: Lab2112 (flickr) Image: Moyan_Brenn (flickr) Image: admiller (flickr) Image: Tjflex2 (flickr) Image: OZinOH (flickr)
11. Why do surveys? Surveys tell us about the population Image: Toby Gray Image: Doug88888 (flickr) Image: ihasb33r (flickr) Image: Hannibal Poenaru (flickr) Image: elycefeliz (flickr) Image: Mikey G Ottowa (flickr) Image: Uriel 1998 (flickr) Image: MowT (flickr) Image: Lab2112 (flickr) Image: Moyan_Brenn (flickr) Image: admiller (flickr) Image: Tjflex2 (flickr) Surveys let us find unknown unknowns Image: OZinOH (flickr)
12. Why do surveys? Surveys tell us about the population Image: Toby Gray Image: Doug88888 (flickr) Image: ihasb33r (flickr) Image: Hannibal Poenaru (flickr) Image: elycefeliz (flickr) Image: Mikey G Ottowa (flickr) Image: Uriel 1998 (flickr) Image: MowT (flickr) Image: Lab2112 (flickr) Image: Moyan_Brenn (flickr) Image: admiller (flickr) Image: Tjflex2 (flickr) Surveys let us find unknown unknowns Image: OZinOH (flickr) - If we knew what the discoveries were likely to be, it would make no sense to build such a telescope George Ellery Hale, 1926
13. An astronomical tiger: 3C273 Image: NOAO/AURA/NSF
14. An astronomical tiger: 3C273 Star? Image: NOAO/AURA/NSF
15. An astronomical tiger: 3C273 Star? Galaxy? Image: NOAO/AURA/NSF
16. An astronomical tiger: 3C273 Star? Galaxy? No! A quasar - the most distant and most luminous objects then identified Image: NOAO/AURA/NSF
17. Unknown unknowns Maarten Schmidt, who identified 3C273
18. Unknown unknowns Maarten Schmidt, who identified 3C273 Not Jesse Greenstein, who didn’t identify 3C48 quickly enough Image: Caltech
19. What’s so difficult? Image: NOAO/AURA/NSF
20. There are a lot of stars! What’s so difficult? Image: NOAO/AURA/NSF
21. There are a lot of stars! What’s so difficult? Astronomers used to measure the position and brightness of each by hand Image: NOAO/AURA/NSF
22. Image: New Scientist
23. The Automated Photographic Measuring Facility Image: New Scientist
24. The Automated Photographic Measuring Facility Image: New Scientist 10 stars a second - a few hours for a survey plate
25. The Automated Photographic Measuring Facility Image: New Scientist 10 stars a second - a few hours for a survey plate - Can we be replaced by a machine?
26. The Automated Photographic Measuring Facility Image: New Scientist 10 stars a second - a few hours for a survey plate - Can we be replaced by a machine? - The answer, perhaps predictably, proves to be a qualified yes. Irwin & Trimble (1984)
27. CCDs were rapidly taken up by astronomers CCDs - Digital Photography
28. CCDs were rapidly taken up by astronomers CCDs - Digital Photography
29. A quarter of the night sky - 469,053,874 objects Sloan Digital Sky Survey
31. Hanny’s Voorwerp Image: William Keel, Anna Manning, 3.5-m WIYN Telescope
32. Hanny’s Voorwerp Image: William Keel, Anna Manning, 3.5-m WIYN Telescope Used to be a quasar
33. Hanny’s Voorwerp Image: William Keel, Anna Manning, 3.5-m WIYN Telescope Used to be a quasar Now we see a light echo
34. Objects that move Objects that vary
35. Objects that move Objects that vary Pan-STARRS
36. Objects that move Objects that vary Pan-STARRS 1.4 billion pixels 6,000 deg2 per night Full sky each week
37. Objects that move Objects that vary Pan-STARRS 1.4 billion pixels 6,000 deg2 per night Full sky each week SkyMapper
38. Objects that move Objects that vary Pan-STARRS 1.4 billion pixels 6,000 deg2 per night Full sky each week SkyMapper Full sky 36 times 500TB in total
39. Spectroscopy - the full rainbow
40. Spectroscopy - the full rainbow What elements are there?
41. Spectroscopy - the full rainbow What elements are there? How are they moving?
42. Spectroscopy - the full rainbow
43. Spectroscopy - the full rainbow
44. Multi-fibre spectroscopy Parry (1998)
45. Robotic fibre positioners Video: CSIRO / AAO 2dF - the 2-degree field
46. Robotic fibre positioners Video: CSIRO / AAO 2dF - the 2-degree field
47. Robotic fibre positioners Video: Andy Green / Greg Poole 2dF - the 2-degree field
48. Robotic fibre positioners Video: Andy Green / Greg Poole 2dF - the 2-degree field
49. (In)complete galaxies
50. (In)complete galaxies
51. (In)complete galaxies
52. Complete galaxies - Integral field
53. Complete galaxies - Integral field
54. SAURON and ATLAS-3D Image: Javier Méndez
55. SAURON and ATLAS-3D Image: Javier Méndez Krajnović et al. (2011)
56. Multi-object integral field Sydney AAO Multi-object Integral field spectrograph
57. SAMI 13 hexabundles --> 13 galaxies --> fastest survey! 1 mm
58. Image: Ned Taylor
59. mirror (closed) Image: Ned Taylor
60. mirror (closed) Image: Ned Taylor
61. mirror (closed) Image: Ned Taylor
62. SAMI
63. SAMI
64. SAMI
71. SAMI
72. SAMI
73. Image: Iraklis Konstantopoulos
74. 3400 galaxies Image: Iraklis Konstantopoulos
75. 3400 galaxies 10 times the size of previous surveys! Image: Iraklis Konstantopoulos
76. 3400 galaxies 10 times the size of previous surveys! 170-200 nights over three years Image: Iraklis Konstantopoulos
77. What will we do with so much data?
78. Why do some galaxies rotate faster than others? What will we do with so much data?
79. Why do some galaxies rotate faster than others? Why are galaxies with lots of neighbours not forming many stars? What will we do with so much data?
80. Why do some galaxies rotate faster than others? Why are galaxies with lots of neighbours not forming many stars? How are heavier elements (oxygen, iron...) distributed within galaxies? What will we do with so much data?
81. Why do some galaxies rotate faster than others? Why are galaxies with lots of neighbours not forming many stars? How are heavier elements (oxygen, iron...) distributed within galaxies? How do supermassive black holes affect galaxies? What will we do with so much data?
82. What will we do with so much data? Watch out for tigers!
83. SAMI’s first discovery
84. SAMI’s first discovery Gas velocity
85. SAMI’s first discovery Gas velocity
86. SAMI’s first discovery ??? Gas velocity
87. SAMI’s first discovery ??? Gas velocity Gas properties
88. SAMI’s first discovery ??? Gas velocity Gas properties
89. SAMI’s first discovery ??? A galactic wind, powered by star formation, carrying gas out of the galaxy Gas velocity Gas properties
90. HETDEX - observe everything!
91. HETDEX - observe everything!
92. HETDEX - observe everything! 60 deg2 total 2.2 million galaxies
93. In conclusion:
94. In conclusion: Surveys form a crucial part of astronomy research
95. In conclusion: Surveys form a crucial part of astronomy research and they keep getting bigger and better
96. In conclusion: Surveys form a crucial part of astronomy research and they keep getting bigger and better Watch out for tigers!
97. In conclusion: Surveys form a crucial part of astronomy research and they keep getting bigger and better Watch out for tigers! j.allen@physics.usyd.edu.au www.sami-survey.org @j_t_allen @SAMI_survey