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Large scale galaxy surveys

Large scale galaxy surveys

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

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James Allen

June 14, 2013
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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
  30. None
  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

  65. None
  66. None
  67. None
  68. None
  69. None
  70. None
  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