Extraterrestrial Effects of Cosmic Rays

So far only interactions of cosmic rays with terrestrial matter have been investigated. If cosmic rays are present in interstellar and intergalactic space, they produce physical changes on extraterrestrial objects also. The question therefore arises if such changes are observable. The following considerations make it probable that this question is to be answered in the affirmative

The quantum theory and the behavior of slow electrons in gases

The new quantum theory(1) is based on the consideration that the only observable frequencies of the atoms and molecules are the so-called jump-frequencies given by the equation ε = hv. In fact the experiments have shown that these are responsible for spectrum lines, anomalous dispersion and inelastic impacts. The revolution frequencies of the electrons in the stationary orbits, as given by the Bohr calculations, it is assumed can never be detected, so that Heisenberg(1) eliminated them from the theory intending to operate with observable data only. There are, however some experiments which have not yet been sufficiently discussed in relation to this problem: namely, the beautiful experiments on the behavior of slow electrons in gases. ("Slow" means that the electrons have less energy than corresponds to a resonance potential of the gas under investigation.) These experiments can be divided into two groups. One class deals with the deviations from the rectilinear motion which the electrons undergo in the field of force of the atoms, while the second class investigates the energy transfer. In this paper we give some considerations on the first type of experiments. The question of the energy transfer will be discussed in a following paper

Intrinsic Properties of Light and Corpuscles from Distant Sources

Spectra of distant nebulae, compared with those of neighboring nebulae, are shifted toward the red by amounts which increase with the distance which the light has traveled. This fact indicates that we are confronted with a phenomenon which involves history on a large scale, history either of the universe as a whole, or history of some of its individual parts. Scientifically speaking, history means the change in time of dimensionless ratios of significant physical quantities. Thus, on the relativistic interpretation of the redshift of light from nebulae the dimensionless ratio D/d between two lengths changes (increases) in time. Appropriate choices for these two lengths are Bohr's characteristic length d = h^2/4π^2me^2 as a supposedly fixed terrestrial measuring stick, and D = V^1/3 where V is the volume which on the average contains one extragalactic nebula. However, many other interpretations of the redshift are possible. The assumption that history must be operative clearly suggests the necessity of an investigation of all dimensionless ratios between significant physical quantities. Only after this investigation has been completed will a final understanding of the redshift and other cosmic phenomena be possible. The following discussion will be concerned with the behavior of the most trivial dimensionless ratios only. A more general program may be outlined, but so far essential data for its realization are lacking

On the Physical Characteristics of the Hydra Cluster of Nebulae

A. Observational Data. - In a previous paper [1] counts of the brighter nebulae in the Hydra cluster were communicated. The distance of the Hydra cluster was estimated as 7.3 X 10^6 parsecs and the average apparent velocity of recession to be expected was given as v = 4100 km./sec. No observations of the red shift for nebulae in the Hydra cluster were available at the time. Dr. Hubble subsequently obtained a spectrum plate for NGC 3309 which nebula is a member of the Hydra cluster. He kindly informs me that the apparent velocity of recession for NGC 3309 is of the order of 3950 km./sec., a value which is in good agreement with our original estimate. B. The Radial Distribution of Nebulae in the Hydra Cluster. - As emphasized previously [1] the Hydra cluster exhibits spherical symmetry and is therefore suspected to have reached a statistically stationary state. In order to check this conclusion two additional tests are available. In the first place we may compare the observed radial distribution of nebulae in the Hydra cluster with the distribution derived by Emden [2] for the bounded isothermal gravitational gas sphere and secondly we can verify whether the ratio wr^2/p0 of the square of the dispersion in radial velocities of the cluster nebulae to the central density po of the cluster can be correctly determined from the observed structural length or structural index a of the cluster [3]

Production of Atomic Rays and of Cosmic Rays in Supernovae

A. Supernovae. - Several years ago, Baade and I made the following suggestions [1]: (1) A class of very rare temporary stars exists, some of whose major physical properties are similar to those of common novae, but in a superlative degree. We proposed that the new stars might appropriately be called supernovae. (2) Supernovae are an origin of the cosmic rays. Our first problem obviously was to locate as many active supernovae as possible in order to prove the correctness of assertion (1). Through the discovery of nine supernovae [2] with the Schmidt Telescope on Palomar Mountain, the solution of this problem has now reached a stage of completeness which is sufficient to allow us to turn our attention to assertion (2). We therefore proceed to outline some of the general processes which presumably take place in supernovae and which are capable of producing cosmic rays as well as atomic rays of high energy

A stone's throw into the universe: A memoir

Early goals in experimental astronomy are recalled. Physio-chemical properties of the atmosphere were studied by observing the tracks and point-to-point spectra of fast particles from artificial meteors. Some of these self-luminous pellets were fired from an Aerobee rocket in 1958

On the relationship between MOND and DM

Numerous astrophysical observations have shown that classical Newtonian dynamics fails on galactic scales and beyond, if only visible matter is taken into account. The two most popular theoretical concepts dealing with this problem are Dark Matter (DM) and Modified Newtonian Dynamics (MOND). In the first part of this paper it is demonstrated that a generalized MOND equation can be derived in the framework of Newtonian Dark Matter theory. For systems satisfying a fixed relationship between the gravitational fields caused by DM and visible matter, this generalized MOND equation reduces to the traditional MOND law, first postulated by Milgrom. Therefore, we come to the conclusion that traditional MOND can also be interpreted as special limit case of DM theory. In the second part, a formal derivation of the Tully-Fisher relation is discussed.Comment: 5 pages, accepted for publication in Astrophys. J. Letter

An Ultraviolet Fe II Image of SN 1885 in M31

Ultraviolet imaging of the remnant of Supernova 1885 in M31 with the Hubble Space Telescope using the F255W filter on the WFPC2 reveals a dark spot of Fe II absorption at the remnant's known position in the bulge of M31. The diameter of the absorbing spot is 0"55 +- 0"15, slightly smaller than, but consistent with, the 0"70 +- 0"05 diameter measured in the higher quality WFPC2 Ca II absorption image previously reported by us. The measured ratio of flux inside to outside SNR 1885 in the Fe II image is 0.24 +- 0.17, consistent with the ratio 0.33 +- 0.04 expected on the basis of a model fit to the previously obtained near-UV FOS spectrum. The observed depth of Fe II absorption suggests that Fe II is fully saturated, with an iron mass in the range M_Fe = 0.1-1.0 Msun. Besides Fe, ion species Mg I, Mg II, and Mn I probably make some contribution to the absorption from the SN 1885 remnant in the F255W image.Comment: 7 pages, including 2 embedded PostScript figures, emulateapj.sty, submitted to Ap

Directional detection of Dark Matter

Among the many experimental techniques available, those providing directional information have the potential of yielding an unambiguous observation of WIMPs even in the presence of insidious backgrounds. A measurement of the distribution of arrival direction of WIMPs can also discriminate between Galactic Dark Matter halo models. In this article, I will discuss the motivation for directional detectors and review the experimental techniques used by the various experiments. I will then describe one of them, the DMTPC detector, in more detail.Comment: 17 pages, 11 postscript figures, mini-review submitted to Modern Physics Letters A (MPLA). Submitted to Modern Physics Letters A (MPLA