AiZ (Zones 2 & 3) Session 2 May 2010 Sue Gunningham [email protected].
Lecture 28: Dark Energy - University of...
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Lecture 28: Dark Energy
Transcript of Lecture 28: Dark Energy - University of...
Lecture 28: Dark Energy
Total Omega = 1 (flat)!
The Case for Dark EnergyI. CMB
II. SNe
III. Baryon Acoustic Oscillations
III. Baryon Acoustic Oscillations (cont.)
The Distant Universe
How do we find distant objects?
look for QSOs, which tend to be far away and luminous
QSO absorption line systems
Ly alpha forest N(HI) < 10^17.2 cm^-2
column density definitions
Ly limit system 10^17.2 < N(HI) < 10^20.3
damped Ly alpha systems N(HI) > 10^20.3
cm^-2
cm^-2
redshift evolution
“dropouts”
Is universe neutral at z > 6?
What are brightest sources in universe?
Gamma Ray Bursts (GRBs)
most distant one so far, z = 6.29
brightest one?
m = 5.8 (visible to naked eye! for 30 sec)
2.5 million times brightest SN
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