J.Phys. G31 (2005) 255-264 We have argued J. Szabelski et al. (2002) that the well-known `ankle' in
the cosmic ray energy spectrum, at logE (eV) ~ 18.7-19.0, marks the transition
from mainly Galactic ...sources at lower energies to mainly extragalactic above.
Recently, however, there have been claims for lower transitional energies,
specifically from logE (eV) ~ 17.0 G. Thompson et al. (2004) via 17.2-17.8
V.S. Berezinsky et al. (2004) to 18.0 A.M. Hillas (2004). In our model the
ankle arises naturally from the sum of simple power law-spectra with slopes
differing by ~ 1.8; from differential slope -3.8 for Galactic particles (near
logE = 19) to ~ -2.0 for extragalactic sources. In the other models, on the
other hand, the ankle is intrinsic to the extragalactic component alone, and
arises from the shape of the rate of energy loss versus energy for the
(assumed) protons interacting with the cosmic microwave background (CMB).
Our detailed analysis of the world's data on the ultra-high energy spectrum
shows that taken together, or separately, the resulting mean sharpness of the
ankle (second difference of the log(intensity*E^3) with respect to logE) is
consistent with our `mixed' model. For explanation in terms of extragalactic
particles alone, however, the ankle will be at the wrong energy - for
reasonable production models and of insufficient magnitude if, as seems likely,
there is still a significant fraction of heavy nuclei at the ankle energy.
Mon.Not.Roy.Astron.Soc. 360 (2005) 236-252 A detailed search has been made for evidence of foreground contributions to
the Cosmic Microwave Background (CMB) WMAP, such foregrounds being related to
...our Galaxy. We find remarkable results. On the largest angular scales we find
significant differences between the power in the fluctuations for positive and
negative Galactic latitudes and between the four Galactic Quadrants. There are
also differences between the power spectrum at latitudes within 10 deg of the
Plane and at higher latitudes. The `slope' of the power spectrum has similar
variations.
In an effort to find the origin of these Galactic-style effects we have
examined the evidence from Galactic gamma rays, specifically from the EGRET
instrument. A correlation is found between gamma ray intensities and the CMB
and other cosmic ray indicators.
Most of the large scale Galactic asymmetries (eg north, south difference and
Quadrant variations) have analogues in cosmic ray asymmetries and also in some
other Galactic properties, such as the column density of gas. Thus, it is
possible to hypothesise on direct cosmic ray-induced contributions, although it
may be that cosmic rays are simply the indicators of Galactic `conditions'
which are influencing the residual CMB fluctuations.
Irrespective of the actual cause of the correlations we have endeavoured to
extrapolate to the situation where the residual foreground is minimised. The
effect on the usually-derived cosmological properties - universal matter
content, ionization, the tensor contribution, tilt and curvature - is briefly
examined.
It is often claimed that there should be a 'GZK cut-off" in the flux of
extragalactic cosmic rays, arising from interactions between the cosmic rays
and the cosmic micro-wave background photons (e.g. ...1 and 2). Some experiments
(3 and 4) show particles of even higher energy than this value and this has led
to claims for exotic processes (e.g. 5 and 6).
We contend that such claims are unnecessary - there is no predicted cut-off,
rather a continuation of the injection spectrum at reduced intensity. We have
combined the world's data and shown that the prediction for a rather flat
injection spectrum (exponent: 1.9 - 2.2) in the case of universal particle
injection provides a reasonable fit to the data. Conventional forms for the
particle attenuation in the intergalactic medium (e.g. 7 and 8) have been
assumed. Either protons or iron nuclei (or a mixture) will suffice.
Attention is drawn to another aspect, too, that of the losses on the
infra-red radiation which may be intense near to strong sources and for sources
in galaxy clusters. The attendant magnetic fields near the sources leads to
significantly long diffusion times through the strong infra-red fields. Two
'case histories' are considered.
Global Warming Some Perspectives Erlykin, AD; Wolfendale, A W; Hanna, E
Journal of environmental science and engineering. B,
04/2012, Letnik:
1, Številka:
4
Journal Article
Here the authors critically review the IPCC's claim that global warming is "very likely" caused by human activity: such a description underestimates the likelihood of the warming being due to this ...mechanism. Next examined are known alternative "natural" mechanisms which could give rise to the warming if, despite many claims, the man-made explanation was false because of compensation effects (greenhouse gases versus aerosol effects). Also, a number of difficulties, as yet unresolved, in the human-induced warming explanation are considered.
A detailed search has been made for evidence of foreground contributions to the Cosmic Microwave Background (CMB) WMAP, such foregrounds being related to our Galaxy. We find remarkable results. On ...the largest angular scales we find significant differences between the power in the fluctuations for positive and negative Galactic latitudes and between the four Galactic Quadrants. There are also differences between the power spectrum at latitudes within 10 deg of the Plane and at higher latitudes. The `slope' of the power spectrum has similar variations. In an effort to find the origin of these Galactic-style effects we have examined the evidence from Galactic gamma rays, specifically from the EGRET instrument. A correlation is found between gamma ray intensities and the CMB and other cosmic ray indicators. Most of the large scale Galactic asymmetries (eg north, south difference and Quadrant variations) have analogues in cosmic ray asymmetries and also in some other Galactic properties, such as the column density of gas. Thus, it is possible to hypothesise on direct cosmic ray-induced contributions, although it may be that cosmic rays are simply the indicators of Galactic `conditions' which are influencing the residual CMB fluctuations. Irrespective of the actual cause of the correlations we have endeavoured to extrapolate to the situation where the residual foreground is minimised. The effect on the usually-derived cosmological properties - universal matter content, ionization, the tensor contribution, tilt and curvature - is briefly examined.
We have argued J. Szabelski et al. (2002) that the well-known `ankle' in the cosmic ray energy spectrum, at logE (eV) ~ 18.7-19.0, marks the transition from mainly Galactic sources at lower energies ...to mainly extragalactic above. Recently, however, there have been claims for lower transitional energies, specifically from logE (eV) ~ 17.0 G. Thompson et al. (2004) via 17.2-17.8 V.S. Berezinsky et al. (2004) to 18.0 A.M. Hillas (2004). In our model the ankle arises naturally from the sum of simple power law-spectra with slopes differing by ~ 1.8; from differential slope -3.8 for Galactic particles (near logE = 19) to ~ -2.0 for extragalactic sources. In the other models, on the other hand, the ankle is intrinsic to the extragalactic component alone, and arises from the shape of the rate of energy loss versus energy for the (assumed) protons interacting with the cosmic microwave background (CMB). Our detailed analysis of the world's data on the ultra-high energy spectrum shows that taken together, or separately, the resulting mean sharpness of the ankle (second difference of the log(intensity*E^3) with respect to logE) is consistent with our `mixed' model. For explanation in terms of extragalactic particles alone, however, the ankle will be at the wrong energy - for reasonable production models and of insufficient magnitude if, as seems likely, there is still a significant fraction of heavy nuclei at the ankle energy.
It is often claimed that there should be a 'GZK cut-off" in the flux of extragalactic cosmic rays, arising from interactions between the cosmic rays and the cosmic micro-wave background photons (e.g. ...1 and 2). Some experiments (3 and 4) show particles of even higher energy than this value and this has led to claims for exotic processes (e.g. 5 and 6). We contend that such claims are unnecessary - there is no predicted cut-off, rather a continuation of the injection spectrum at reduced intensity. We have combined the world's data and shown that the prediction for a rather flat injection spectrum (exponent: 1.9 - 2.2) in the case of universal particle injection provides a reasonable fit to the data. Conventional forms for the particle attenuation in the intergalactic medium (e.g. 7 and 8) have been assumed. Either protons or iron nuclei (or a mixture) will suffice. Attention is drawn to another aspect, too, that of the losses on the infra-red radiation which may be intense near to strong sources and for sources in galaxy clusters. The attendant magnetic fields near the sources leads to significantly long diffusion times through the strong infra-red fields. Two 'case histories' are considered.