The Redshift of Light Emitted by Nearby and Distant Galaxies in the Observable Universe

 

The Redshift of Light Emitted by Nearby and Distant Galaxies

 in the Observable Universe

Pavle I. Premović,

Laboratory for Geochemistry, Cosmochemistry&Astrochemistry,

University of Niš, pavleipremovic@yahoo.com, Niš, Serbia

                                                                                                   So, we are an observer on a planet traveling in an unknown

                                                                                                     direction at an unknown speed and we are observing galaxies 

                                                                                                  also traveling in unknown directions at unknown speeds and 

                                                                                           still not knowing how fast they are moving away from us. 

                                                                                              The only thing we do know in a few cases their approximate

                                                                                             distance. This is inspired by Andy Bradford, March 7, 2015.

Most cosmologists consider that the expansion of the Universe from the initial Big Bang causes that wavelength of light coming from nearby and distant galaxies[1] to increase or show the cosmological redshift (or more commonly just redshift) z_G. This expansion is caused by the stretching of space (or better space-time) itself. 

However, the ultraviolet surface brightness data of nearby and distant galaxies, over a very wide redshift range imply that the observable Universe is the non-expanding (Euclidean) Universe (NEEU) [1, and references therein]. Moreover, a detailed analysis of the gamma-ray burst sources performed by Sanejouand {2} suggests that this Universe has been Euclidean and static over the last 12 Gy. To explain the redshift, Premović {3} hypothesized that the speed of light emitted by nearby and distant galaxies in NEEU is superluminal. 

In general, we can assume that the measured wavelength, λ_G, of nearby and distant galaxies, comprises two parts: the first one, λ_BB, which results from the Big Bang Universe (hereinafter BBU) expansion and the second one, λ_AC, arises from another cause. So, we write that the measured wavelength

λ_G = λ_BB + λ_AC    … (1).

There are three possible cases: (a) there is no additional cause λ_AC = 0 or its contribution to the measured wavelength λ_G is negligible, then the observable universe is the Big Bang type; (b) a contribution of the BBU expansion λ_BB to the measured wavelength λ_G is negligible or equal zero, then the observable universe is NEEU; and, (c) though the BBU expansion contributes predominantly to the measured wavelength λ_G the wavelength contribution of another cause is not negligible.

Similarly to the above-measured wavelength λ_G, we can assume that this redshift of light coming from nearby and distant galaxies z_G[2] is made of two parts: the first one, z_BB, which results from BBU expansion and the second one, z_AC, derived from another cause

z_G = z_BB + z_AC    … (2).

The three possible cases, which correspond to the above cases for the wavelengths λ_G, λ_BB and λ_AC, can also be derived for z_G, z_BB and z_AC. They are:  (a) there is no additional cause z_AC = 0 or its contribution to the redshift z_G is negligible, the observable Universe is BBU; (b) a contribution of BBU expansion z_BB to the redshift z_G is equal zero or is negligible, then the observable Universe is NEEU; and, (c) though the redshift of BBU expansion, z_BB, is predominant to redshift z_G the redshift contribution of another cause, z_AC, is not negligible.

Since we cannot separate these wavelength or redshift contributions of nearby and distant galaxies to their corresponding total counterparts (λ_G and z_G), we do not know if the observable Universe:   BBU or not. 

Hubble’s law states that a distance D_G from Earth to nearby galaxies in BBU or NEEU is linearly related to its redshift z_G {3}. It can be written as

D_G = z_Gc/H₀    … (3).

where c (≈ 3×10⁸ m sec^-1) is the speed of light and H₀ is the Hubble constant. The value is still uncertain and ranges from 50 km sec^-1 (Mpc)^-1 – 100 km sec^-1 (Mpc)^-1). This law is valid for nearby galaxies. As we noted previously, once z_G becomes ≥ 0.1 and we are dealing with distant galaxies[1], this relationship is no longer linear and becomes dependent on the particular cosmological model.

Combining the equations (2) and (3) we get

                                                                 D_GH₀/c = z_BB + z_AC

Of course, this equation is only valid for nearby galaxies in BBU. If a contribution to the redshift z_G of another cause z_AC is equal to zero then D_GH₀/c ≈ z_BB and the Hubble constant H₀ represent the constant rate of BBU expansion.

 

For convenience, we write the above equation

z_AC = D_GH₀/c – z_BB … (4).

To estimate the contribution other than the contribution of BBU expansion to the measured redshift z_G we have to know the distance of nearby galaxies – D_G. This distance is rather uncertainly known except for a few of these galaxies whose distance is directly measured by the megamaser method [3, and references therein]. However, since the Hubble constant is also quite uncertain, the contribution of another cause z_AC is also quite uncertain.

For example, the galaxy NGC 6264 with z_G = 0.03384, the farthest “megamaser” galaxy, is at a distance 447 Mly {3, and references therein}.  Using eqn. (3) and the Hubble length c/H₀ = 72 km sec^-1 we calculate z_G = D_GH₀/c = 447 Mly/13.65 Gly = 0.03275. The difference is 0.03384 – 0.03275 = 0.00109 or the percentage difference is about 3 %.

 

References

{1} E. J. Lerner, Observations contradict galaxy size and surface brightness predictions that are based on the expanding universe hypothesis. Monthly notices the Royal Astron. Soc. (MNRAS) 477, 3185-3196 (2018).

{2} Y. –H Sanejouand, About some possible empirical evidences in favor of a cosmological time variation of the speed of light. Europhys. Lett., 88, 59002  (2009).

{3} P. I. Premović, Distant galaxies in the non-expanding (Euclidean) Universe: the light speed redshift. The General Science Journal, December 2021. 

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[1] We will define nearby galaxies as those whose redshift z_G is from 0.001 to 0.1 (or 0.001 ≤ z_G ≤ 0.1) and distant galaxies with z_G > 0.1. Of course, there is no sharp boundary between nearby and distant galaxies.

[2] Of course, λ_G and z_G are related to each other.

[3] Contribution of their peculiar motion to the redshift is negligible [3].

 

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