Query on Cosmic Dark Energy by Error Analyses of Type Ia Supernova

1. Query on Cosmic Dark EnergybyError Analyses of Type Ia Supernova Qiu-he Peng (Depart. of Astronomy, Nanjing University)

2. §IQuestion of “Cosmic Dark Energy”

3. Origin of the Question of “Cosmic Dark Energy” “Cosmic Dark Energy”←“Acceleration of the Universe” ←Observation of remote SNIa with z > 0.5 + Taking SNIa as a Standard Candle Power (Assumption) ← Standard Picture of SNIa Explosion : SNIa Explode when Mass of Accreting White Dwarf (in binary system) reaches at Chandrashkar critical mass Ye :fraction of electrons

4. Supernova Light Curves

5. SNIa as A Standard Candle Light Curves and spectrums are similar for almost all SNIa Mmax(- 18m) – ( -20m); Mmax= -2.5 log10 L It seems is very close. It may be take as a standard candle at the maximum luminosity of SNIa M= m + 5 – 5log D(pc) – A + K A: interstellar extinction ; K: correct by redshift of galaxies The distance of SNIa may be determined by measuring its apparent luminance (m) when M is given m – M +A – K =  …… “distance modulus ” ( = 5log D(pc) – 5)

6. Phillips relation  Reducing SNIa as a standard candle Phillips (1993) suggests a semi-experience relation by observation Δm15:decrease in apparent luminance during 15 days after the maximum luminance First, For some given SNIa with low redshift which their distances are given by another way of distance determination(e.g. by observation of cepheid variables ), we may get their Mmax by observations of their apparent luminance (m) at the moment of maximum brightness. We may get the two parameters (a, b) through statistics by Mmax and observations of Δm15 . Then, We may caculateMmax by measuring Δm15 for the remote SNIa From the formula above. But, This is only an assumption no any reason on theory. i.e. No physics.

7. Advanced Phillips Way Advanced Phillips Way (1996 – 2007) : They are based on two assumptions: a) luminosity is related with the width of the light curve of SNIa; b) luminosity is related with the color index (B-V) in the course of explosion SNIa It is a very complicated statistical relation. SALT2 (Guy, J. et al., 2007)  Software to deal with observational data of SNIa 

8. continue The spectral energy distribution of light curve for SNIa: F(SN, p, λ)= x0[M0(p, λ) + x1M1(p, λ) + ...] exp{cCL(λ)} P: time(day) from the maximum moment in B wave band at the rest reference system. • : wavelength at the reference system of SNIa. M0(p,): a function of spectral evolution with time in average for SNIa Mk(p,): (k>0) Describing variance of other factors X1: describing the width of the light curve for SNIa CL(λ): corresponding to a color correction function in average c = (B -V )MAX -< B -V > : variance of color index Mk(p,) andCL(λ)describing the global behavior of SNIa c , xi : parameters of each SNIa

9. continue Distance modulus of the SNIa

10. 2 check test

13. Nobel Price for Physics in 2011 • Riess et al. (1998), Perlmutter et al. (1999) , Guy, J., et al. (2007, SALT2) • Amanullah, R., et al. (2010, UNION2) • By observation of SNIa with high redshift • Accelerating expansion of the Universe •  Cosmic Dark Energy •  • Perlmutter, Smith and Riess have got the Nobel Price for Physics in 2011

14. §IIStandard Candle of SNIais rejected by Recent progress of researches on SNIa

15. Recent progress of researches on SNIa • The Progenitor of SN Ia Tych(1572) has not been found up to now. 2. The total mass of the remnant of SNIa Tych(1572) mSNR >1.8 mSun rather than mSNR <1.4 mSun (Chandrashkar critical mass ) → “Standard Picture of SNIa Explosion” is rejected. → The physical basis of both Philips relation and advanced Philips way are lost. The Standard candle of SNIa is only an assumption on theory without physical basis . i.e. No physics.

16. Asymmetry explosion of SNIa It is shown that material distribution in some remnant of SNIa are obviously asymmetry in space direction by observation. (Kasen D., 2010, Nature, 466,37-38).It is also confirmed by simulation: (Maeda K. et al., 2010, Nature, 466, 82-85) It is shown that the visual brightness of SNIa depends on the direction of observer. Then the Phillips’ (and advanced Phillips’) mathord is unphysical.

17. §IIIQuery on Accelerating expansion of the Universe byError analyses

18. Query on the error analyzing both Philips relation and advanced Philips way are Assumptions or they are mathematic models without physical basis only. The Set of SNIa after deal with by SALT2(software) is just a set of “modeling SNIa” , rather than real set of SNIa. There are some serious flaws in the error statistics for all previous researches:

19. Some flaws in the error analysis of SNIa observation However, the based assumption of standard candle power of SNIa has been negated by progress of researches on SNIa recent years. Besides, Some serious flaws are in the error analysis of those papers: • Error of absolute magnitude at maximum luminance (for SNIa ) caused by the advanced Phillips’ way has not been included. 2 The set of modeling SNIa in their papers (Amanullah, R., et al.(2010) (including685 SNIa) is really noGaussian distribution . it is incorrect to find the intrinsic error of SNIa by 2 check test method.

20. 1. NoGaussian distribution for the set of modeling SNIa

21. 2. Errors of the absolute magnitude for SNIa

22. The Statistic distribution of the absolute magnitude at maximum luminosity for SNIa Complete date（interval per 0.2mag）

24. Averaged total observational error of the distance modulus

25. Redo the statistics

26. Varies of (average) The observational error of the distance modulus with redshift of SNIa (our methord)

27. The residual error for the distance modulus of SNIa.

28. Conclusion

29. Conclusion

30. Problem on Period-luminosity relationof Cepheid variables

31. Thanks