Determination of the cosmological constant L due to hypothetical SNe Ia

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Determination of the cosmological constant L
due to hypothetical SNe Ia

• Bochum, October 23, 2003
• DIPLOMA THESIS
• Peter Erni
• under the supervision of
• Prof. Dr. phil. Gustav Andreas Tammann
• Astronomisches Institut der Universität Basel
• Venusstrasse 7
• CH-4102 Binningen

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Determination of L due to hypothetical SNe
Ia_______________________________________________
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INTRODUCTION

• Distance measurement and SNe Ia
• High-z SNe Ia as standard candles?

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• Distance Measurement
• Cepheids
• Tully-Fisher Relation
• SNe Ia

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SNe Ia as standard candles

• SNe Ia are the best known standard candles today.
• Is this also true for far SNe Ia?
• SNe Ia are very sensible to metallicity.
• The quality of high z SNe Ia as standard
  candles is doubtful.

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STATUS QUO AND ANALYSIS

• Fiducial sample
• Hubble diagram
• Luminosity scatter
• Hypothesis and c2-Test

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Fiducial Sample
65 SNe Ia

• z lt 0.1 or v lt 30000 km/s
• blue at maximum (B-V) 0.m06
• corrected for Galactic absorption Av
• corrected for decline rate ?m15
• (see also Parodi et al., 2000)

35 (blue) SNe Ia

• Av lt 0.m2
• v gt 12000 km/s

26 SNe Ia (fiducial sample) scatter s 0.118
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Determination of L due to hypothetical SNe
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The correcting terms are
The 26 SNe Ia define Hubble Diagram of the form
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Determination of L due to hypothetical SNe
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Hubble Lines by numerical integration Caroll,
Press Turner, 1992
CSTB,V,I
term2(z)
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Applying a scatter via the Monte-Carlo Method
(shyp 0.12)
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Hubble Diagramwith 200 hypothetical SNe Ia up to
z ? 0.16
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Hypothesis and c2-Test H1 The Universe is flat
and L-dominated (O? 0.7 und Om 0.3).
H2 The Universe is flat and consists only of
matter (O? 0 und Om 1).

• Proceeding
• Best fit of the Hubble Line according to H1
  through the fiducial sample
• Distributing and scattering 200 hypothetical SNe
  Ia
• Best fit of the Hubble Line according to H2
  through the 200 SNe Ia
• c2Test

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Determination of L due to hypothetical SNe
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RESULTS

• Confidence-Level Plot
• Discussion and outlook

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H1 versus H2 Null hypothesis H0
H1 Probability to exclude H2 respectively
favorite H1? Results z ? 0.12 and 200 SNe
Ia 79 ? 11 z ? 0.16 and 200 SNe Ia 90
? 6 z ? 1.00 and 200 SNe Ia 96 ? 2
Generalization (?Confidence Level Plot)
H3 The density parameter of the Universe are
O? ? 1.5, 3, Om ? 0, 3 where O? Om 1.
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Determination of L due to hypothetical SNe
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Confidence Level Plot
N 26
N 200
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• Discussion Outlook
• Sensibility

• Lookback Time and Metallicity

• The GAIA satellite