Harrison baryon inhomogeneity postulate of galactic evolution critically analyzed for universality of cosmic ray

Noerdlinger, P. D.

English

NASA Technical Reports Server

https://ntrs.nasa.gov/search.jsp?R=19680023945 2020-03-12T06:28:57+00:00Z
i 
Universal Cosmic Rays and 
Harrison's Inhomogeneity Postulate* 
by 
Peter D. Noerdlinger 
Department of Physics and Astronomy 
University of Iowa 
Iowa City, Iowa 52240 
,August 1968 
-. 3 ~ 
, " 
-/&p Oa/ - 0 0 2  
36 * This work supported in part by the National Aeronautics and 
Space Administration grant NASAC_NsG 233-62) 
1 
ABSTRACT 
Cosmologies of the type suggested by Harrison, in which 
initial baryon inhomogeneity leads to the formation of galaxies, 
are shown to preclude the possibility that cosmic rays are universal. 
The postulate has recently been introduced by Harrison’ 
that the distribution of baryon number density i n  the universe was 
primordially inhomogeneous over regions suff ic ient ly  large that 
when the temperature f e l l  suff ic ient ly  t o  favor annihilation, locdl 
excesses of baryons (or anti-baryons) remained of sufficient s i ze  
t o  condense in to  galaxies under the influence of gravitation. 
Harrison se t s  no expl ic i t  upper l i m i t  t o  the  s i z e  region he wishes 
t o  develop in to  an all-baryon or all-anti-baryon region, but h i s  
model seems t o  lead t o  regions not much larger i n  mass than a 
galaxy, fo r  two reasons. On one hand, it i s  necessary t o  assume t h e  
inhomogeneity, rather than derive it, and the assumption seems more 
radical  the larger  the  region. 
gravitational contraction of a typical region lead t o  formation of 
a galaxy. 
On the  other hand, it i s  intended tha t  
In fac t ,  Harrison expl ic i t ly  refers2 t o  the possible 
existence of condensations or blobs of anti-matter within matter 
galaxies, and conversely. The postulate tha t  baryon inhomogeneity leads 
t o  galactic formation seems at t ract ive,  because it requires less by 
way of assumed i n i t i a l  inhomogeneity amplitude than theories based on 
primordial density inhomogeneity. W e  therefore explore the conse- 
quences of the theory in the realm of cosmic rays. 
3 7 4  
It i s  an open question as t o  whether cosmic rays are galactic 
or universal, Evidence as t o  the abundance of heavy elements i n  the 
6, 6 
dlstant past 
matter, but the presently available evidence is  insufficient.  It 
could well be crucial  i n  reaching a decision on t h i s  
i s  possible t o  show, however, t ha t  universal cosmic rays are ruled 
out i n  Harrison's cosmology. Under the universal cosmic ray 
hypothesis, it must be assumed tha t  a negligable fraction7 come 
from nomal galaxies. Therefore the majority of cosmic rays i n  our 
galaxy would have come from other sources, and have diff'used in to  
the  galaxy. 
as 5x 10 y a f te r6  the  primordial f i reba l l .  
The t i m e  of generation could w e l l  have been as early 
The ea r l i e r  the time 8 
of generation, the more chance cosmic rays from anti-matter regions have 
have had t o  diffise t o  us. 
negligable source i n  a universal cosmic ray theory, it i s  unavoidable 
that cosmic rays must have diff'used in to  o w  galaxy from sources 
But since our own galaxy must be a 
at  l e a s t  as dis tant  as the f e w  nearest galaxies, - 0.5 Mpc. Now, 
whatever t he  sources of cosmic rays, i n  Harrison's cosmology they 
must produce roughly equal number of par t ic les  and anti-particles,  
-
when averaged over a few galaxies. But It has been shown experi- 
mentally tha t  cosmic rays contain less than 0.1% antiprotons' and 
that the  r a t i o  of anti-nuclei t o  nuclei for  Z > 2 i s  less than 
0.19. 
galact ic  origin. 
Therefore, i f  Harrison's postulate holds, cosmic rays are of 
The author i s  indebted t o  the  National Aeronautics and Space 
d v c : X - 1 6 - 8 ~ / - ~ 0 L  
Administration for  support under grant NAS@sG 2 3 - 6 3  
FOOTNWES 
1. 
2. 
3. 
4, 
5. 
6. 
7. 
8. 
9. 
E. R. Harrison, Phys. Rev. 
E. R. Harrison, Phys. Today L 21, 31 (1968). 
R. J. Gould, Am. J. Phys. 35, 376 (1967). 
-.II 167, 11.70 (1968). 
V. L. Ginzburg and S. I. Syrovatskii, The Origin of Cosmic Rays, 
The M a c m i l l a n  Co., New York, 1964. See e spec iz ly  p. 282 - - - -  
and the note on p: 277. 
mid,  p. 259. 
P, B. Price, R. S. Rajan, and A. S. Tamhane, Astrophys. J. 
(Letters) - 151, LlOg (1968), and other references c i ted  
therein. 
Ref. 4, p. 264. 
H. Aizu, Y. Fujkoto,  S. Hasegawa, M. Koshiba, I. Mito, J. 
Nishimura, K. Yokoi, and M. Schein, Phys. Rev. - 121, 1206 
(1961) 
N. L. Grigorev, D. A. Zhuravlev, M. A. Kondrateva, 1. D. 
Rappaport, and I. A. Savenko, Zh. Ezperim. i Teor. Fiz .  - 9  45 
394 (1964) [English transl . :  Soviet Phys. -- JETP -9 18 
272 (1964),1 


Universal cosmic rays and Harrison's inhomogeneity postulate

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server