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Type IA Supernovas

Type IA Supernovas. Nicklaus Traeden. Outline. Background Cosmology Background Cosmic Distance Ladder Observation History Supernova Physics Technique Current instruments Results Problems Future Projects. Background. Cosmic Distance Ladder //pretty picture here. History.

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Type IA Supernovas

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  1. Type IA Supernovas Nicklaus Traeden

  2. Outline • Background • Cosmology Background • Cosmic Distance Ladder • Observation History • Supernova Physics • Technique • Current instruments • Results • Problems • Future Projects

  3. Background • Cosmic Distance Ladder • //pretty picture here

  4. History

  5. Supernovae • Supernovae through history • Recorded as early as 185 CE • Most widely known is SN 1054 • Produced crab nebula • Type II m = -6.00 • 6500 ly away • SN1006 is brightest stellar event • Type Ia m = -7.50 • 7200 ly • More discoveries with telescopes • SN 1604 – “Kepler’s Star”

  6. Spectral Identification Core Collapse Supernovae

  7. White dwarf • Electron degeneracy • Give relationship between M and R • Want mass limit • Chandrasekhar Limit ~ 1.4 solar Masses

  8. Background

  9. Type Iacontinued • 2 12C + 2 16O 56Ni 56Co 56Fe • ~1044 J • ejecting matter ~6% c • Mv = −19.3 (about 5 billion times brighter than the Sun) http://youtu.be/_zw6Eih7QG0

  10. Light Curve

  11. Stretch factor

  12. Background • Data gathered – S. Perlmutter et al. 1999 • //graph

  13. Technique

  14. Technique • Current Surveys • Low z • SDSS, LOSS/LOTOS • Medium z • supernovae legacy survey (SNLS) • z<1 • High z • HST • Results

  15. Low Z surveys • z<0.03 • LOSS/LOTOS - over 1000 SNe surveyed • Carnegie Supernova Project (CSP) – IR light curves • SN Factory – 600 SNe in 2 years • Catalina Real-Time Transit Survey • Covers 26000 square degrees • Amateur • Needed for proper calibration of SNe 1a • Used to determine SNe rates

  16. Intermediate z surveys • SDSS – z=0.05-0.4 • CSP – z>0.3

  17. High z surveys • Supernova Cosmology Project • CFHT + MegaCam • 4 filters six years, rolling search • GOODS HST SN Search • High z (z>1.2) • HST Cluster Supernova Survey • 0.9 < z < 1.5

  18. Results

  19. Results • Results

  20. Cosmological constraints • Consistent with a flat, dark energyw = -1 universe • Supernova Legacy Survey 2011

  21. Possible Problems • Practical Problems • IR, Sne rarity, • Astrophysical Uncertainty • Systematic Error • Calibration uncertainty

  22. Practical Problems • SNe 1a are rare. • 1 per galaxy per millennia • Telescope needs to re-sweep the same area often • Want SNe @ high redshift. • Shifts spectrum into IR • IR is both absorbed and created by the atmosphere.

  23. Astronomical Uncertainty • All Type IaSNe are the same • All light curves are from Type IaSne • White dwarf collisions • Reddening / extinction

  24. Systematic Error • Instrument error • Calibration Error • Filter uncertainty

  25. Future Projects • WFIRST • Microlensing Planet Finder • Joint Dark Energy Mission/Omega • Near Infrared Sky Surveyor

  26.  a 288-megapixel focal-plane array with a pixel size of 110 milliarcseconds • an integral field spectrograph • 2.4 m diameter • Field ~200 x bigger than HST

  27. WFIRST • Survey will use 0.5 years of observing over a 2 year period. • Projected to measure 2700 Type 1a SNe • 0.2<z<1.7

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