The Local Bubble and Interstellar Material Near the Sun

The properties of interstellar matter (ISM) at the Sun are regulated by our location with respect to the Local Bubble (LB) void in the ISM. The LB is bounded by associations of massive stars and fossil supernovae that have disrupted natal ISM and driven intermediate velocity ISM into the LB interior void. The Sun is located in such a driven ISM parcel. The Local Fluff has a bulk velocity of 19 km/s in the LSR, and an upwind direction towards the center of the gas and dust ring formed by the Loop I supernova remnant interaction with the LB. When the ram pressure of the LIC is included in the total LIC pressure, and if magnetic thermal and cosmic ray pressures are similar, the LIC appears to be in pressure equilibrium with the local hot bubble plasma.Comment: Proceedings of Symposium on the Composition of Matter, honoring Johannes Geiss on the occasion of his 80th birthday. Space Science Reviews (in press

The Magnificent Seven in the dusty prairie

Abstract The Magnificent Seven have all been discovered by their exceptional soft X-ray spectra and high ratios of X-ray to optical flux. They all are considered to be nearby sources. Searching for similar objects with larger distances, one expects larger interstellar absorption resulting in harder X-ray counterparts. Current interstellar absorption treatment depends on chosen abundances and scattering cross-sections of the elements as well as on the 3D distribution of the interstellar medium. After a discussion of these factors we use the comprehensive 3D measurements of the Local Bubble by Lallement et al. (2003) to construct two simple models of the 3D distribution of the hydrogen column density. We test these models by using a set of soft X-ray sources with known distances. Finally, we discuss possible applications for distance estimations and population synthesis studies. Keywords neutron stars · absorption · ISM · X-ray:general

Ultraviolet studies of interacting binaries

Interacting Binaries consist of a variety of stellar objects in different stages of evolution and those containing accreting compact objects still represent a major challenge to our understanding of not only close binary evolution but also of the chemical evolution of the Galaxy. These end-points of binary star evolution are ideal laboratories for the study of accretion and outflow processes, and provide insight on matter under extreme physical conditions. One of the key-questions of fundamental relevance is the nature of SN Ia progenitors. The study of accreting compact binary systems relies on observations over the entire electromagnetic spectrum and we outline here those unresolved questions for which access to the ultraviolet range is vital, as they cannot be addressed by observations in any other spectral region

The involvement of aβ in the neuroinflammatory response

In the same year as Alzheimer described the case of Auguste D. as a peculiar disease of the cerebral cortex, Fischer published his classic paper about miliary plaque formation in a large number of brains from patients with senile dementia [1]. In this paper and a following one from 1910, Fischer stated that plaque formation is the result of the deposition of a peculiar foreign substance in the cortex that induces a regenerative response of the surrounding nerve fibers [2]. He described spindle-shaped thickening of nerve fibers terminating with club forms in the corona of plaques (Fig. 4.1). These altered nerve fibers were considered as axonal sprouting, and the terminal club forms showed a strong similarity with the clubshaped buddings of axons found in developing nerve fibers and after transections of peripheral nerves as described by Cajal some years earlier. According to Fischer, the crucial step of the plaque formation is the deposition of a foreign substance that provokes a local inflammatory response step followed by a regenerative response of the surrounding nerve fibers. However, Fischer could not find morphological characteristics of an inflammatory process around the plaques after extensive histopathological observations including complement binding studies. The only tissue reaction appeared to be an overgrowth of club-formed neurites