Approximating function to The Hubble Diagram to Redshift > 6 from 69 Gamma-Ray Bursts
Distance moduli
u as function of redshift z.
u = m - M = 5* log (d_L) + 25,
(d_L in units of megaparsecs),
d_L = luminosity distance,
u = distance moduli,
m = apparent magnitude,
M = absolute magnitude.
I made following approximative function of distance moduli u (magnitudes)
as function of redshift z of 69 GRBs.
GRB data ( 0.17 < z < 6.60 ):
----------------------------
u = 2.5649*ln(z) + 44.159 ,
R^2 = 0.9011 , correlation coefficient for logaritmic approximation.
Quite large error bars of distance moduli are (Table 6 / pp. 69-70)
from minimum +- 0.38 to +- 1.33 magnitudes.
Anyhow comparing my previous article formulae (data from Supernovae Type Ia,
(0 < z < 1.390)
SNIa data 2006 (0 < z < 1.390):
------------------------------
u = 2.3935*ln(z) + 44.172 ,
R^2 = 0.9914 , correlation coefficient for logaritmic approximation.
SNIa dada 2007 uppdated (0 < z < 1.390):
---------------------------------------
u = 2.4175*ln(z) + 44.163 ,
R^2 = 0.9948 , correlation coefficient for logaritmic approximation.
These GRB measurements from reference 1 (even though quite large error bars)
at least give approximately same approximate functions.
References:
1. Schaefer Bradley, 2006.
The Hubble Diagram to Redshift > 6 from 69 Gamma-Ray Bursts.
arXiv:astro-ph/0612285v1 11 Dec 2006.
Table 6, pp. 69-70, pp. 59-88, 88 pages.
2. Riess Adam G. et al. 2007.
New Hubble Space Telescope Discoveries of type Ia Supernovae at z => 1:
Narrowing constraints in the Early Behaviour of Dark Energy.
The Astrophysical Journal 659:98-121, 2007 April 10.
pages 106-111. Table 4 on page 109 (distance normalization is arbitrary,
0 < z < 1.390 ), Figure 6 on page 110.
3. SN Ia 2006 data / SN Ia 2007 updated data mentioned above article
is taken from the reference:
http://braeburn.pha.jhu.edu/~ariess/R06 .
4. Poropudas Hannu, 2016.
Extiction-corrected Distance Modulus u_o as a function of Redshift z of SN Ia data 2006 and 2007.
sci.physics.relativity,
Thu, 14 Jan 2016 01:16:47 -0800 (PST),
Message-ID: <
d08cf609-461c-44a3...@googlegroups.com>.
5. Poropudas Hannu, 2016.
Extinction-corrected Distance Modulus u_0 as a function of Redshift z.
sci.astro.research,
Sat, 16 Jan 2016 19:30:14 -0800 (PST),
Approved:
sci.astro.res...@slimy.greenend.org.uk (jt),
Message-ID: <
74a3be85-d6e1-4ae6...@googlegroups.com>.
(same article as 4.)
Best Regards,
Hannu Poropudas
Kolamäentie 9E,
90900 Kiiminki / Oulu,
Finland