Strongly magnetized pulsars: explosive events and evolution

Well before the radio discovery of pulsars offered the first observational confirmation for their existence (Hewish et al., 1968), it had been suggested that neutron stars might be endowed with very strong magnetic fields of $10^{10}$-$10^{14}$G (Hoyle et al., 1964; Pacini, 1967). It is because of their magnetic fields that these otherwise small ed inert, cooling dead stars emit radio pulses and shine in various part of the electromagnetic spectrum. But the presence of a strong magnetic field has more subtle and sometimes dramatic consequences: In the last decades of observations indeed, evidence mounted that it is likely the magnetic field that makes of an isolated neutron star what it is among the different observational manifestations in which they come. The contribution of the magnetic field to the energy budget of the neutron star can be comparable or even exceed the available kinetic energy. The most magnetised neutron stars in particular, the magnetars, exhibit an amazing assortment of explosive events, underlining the importance of their magnetic field in their lives. In this chapter we review the recent observational and theoretical achievements, which not only confirmed the importance of the magnetic field in the evolution of neutron stars, but also provide a promising unification scheme for the different observational manifestations in which they appear. We focus on the role of their magnetic field as an energy source behind their persistent emission, but also its critical role in explosive events.Comment: Review commissioned for publication in the White Book of "NewCompStar" European COST Action MP1304, 43 pages, 8 figure

X-ray emission from isolated neutron stars

X-ray emission is a common feature of all varieties of isolated neutron stars (INS) and, thanks to the advent of sensitive instruments with good spectroscopic, timing, and imaging capabilities, X-ray observations have become an essential tool in the study of these objects. Non-thermal X-rays from young, energetic radio pulsars have been detected since the beginning of X-ray astronomy, and the long-sought thermal emission from cooling neutron star's surfaces can now be studied in detail in many pulsars spanning different ages, magnetic fields, and, possibly, surface compositions. In addition, other different manifestations of INS have been discovered with X-ray observations. These new classes of high-energy sources, comprising the nearby X-ray Dim Isolated Neutron Stars, the Central Compact Objects in supernova remnants, the Anomalous X-ray Pulsars, and the Soft Gamma-ray Repeaters, now add up to several tens of confirmed members, plus many candidates, and allow us to study a variety of phenomena unobservable in "standard'' radio pulsars.Comment: Chapter to be published in the book of proceedings of the 1st Sant Cugat Forum on Astrophysics, "ICREA Workshop on the high-energy emission from pulsars and their systems", held in April, 201

Reaction rates and transport in neutron stars

Understanding signals from neutron stars requires knowledge about the transport inside the star. We review the transport properties and the underlying reaction rates of dense hadronic and quark matter in the crust and the core of neutron stars and point out open problems and future directions.Comment: 74 pages; commissioned for the book "Physics and Astrophysics of Neutron Stars", NewCompStar COST Action MP1304; version 3: minor changes, references updated, overview graphic added in the introduction, improvements in Sec IV.A.

Using European travellers as an early alert to detect emerging pathogens in countries with limited laboratory resources

BACKGROUND: The volume, extent and speed of travel have dramatically increased in the past decades, providing the potential for an infectious disease to spread through the transportation network. By collecting information on the suspected place of infection, existing surveillance systems in industrialized countries may provide timely information for areas of the world without adequate surveillance currently in place. We present the results of a case study using reported cases of Shigella dysenteriae serotype 1 (Sd1) in European travellers to detect "events" of Sd1, related to either epidemic cases or endemic cases in developing countries. METHODS: We identified papers from a Medline search for reported events of Sd1 from 1940 to 2002. We requested data on shigella infections reported to the responsible surveillance entities in 17 European countries. Reports of Sd1 from the published literature were then compared with Sd1 notified cases among European travellers from 1990 to 2002. RESULTS: Prior to a large epidemic in 1999–2000, no cases of Sd1 had been identified in West Africa. However, if travellers had been used as an early warning, Sd1 could have been identified in this region as earlier as 1992. CONCLUSION: This project demonstrates that tracking diseases in European travellers could be used to detect emerging disease in developing countries. This approach should be further tested with a view to the continuous improvement of national health surveillance systems and existing European networks, and may play a significant role in aiding the international public health community to improve infectious disease control

Space-borne Bose-Einstein condensation for precision interferometry

Space offers virtually unlimited free-fall in gravity. Bose-Einstein condensation (BEC) enables ineffable low kinetic energies corresponding to pico- or even femtokelvins. The combination of both features makes atom interferometers with unprecedented sensitivity for inertial forces possible and opens a new era for quantum gas experiments. On January 23, 2017, we created Bose-Einstein condensates in space on the sounding rocket mission MAIUS-1 and conducted 110 experiments central to matter-wave interferometry. In particular, we have explored laser cooling and trapping in the presence of large accelerations as experienced during launch, and have studied the evolution, manipulation and interferometry employing Bragg scattering of BECs during the six-minute space flight. In this letter, we focus on the phase transition and the collective dynamics of BECs, whose impact is magnified by the extended free-fall time. Our experiments demonstrate a high reproducibility of the manipulation of BECs on the atom chip reflecting the exquisite control features and the robustness of our experiment. These properties are crucial to novel protocols for creating quantum matter with designed collective excitations at the lowest kinetic energy scales close to femtokelvins.Comment: 6 pages, 4 figure

Genome-Wide Distribution of RNA-DNA Hybrids Identifies RNase H Targets in tRNA Genes, Retrotransposons and Mitochondria

During transcription, the nascent RNA can invade the DNA template, forming extended RNA-DNA duplexes (R-loops). Here we employ ChIP-seq in strains expressing or lacking RNase H to map targets of RNase H activity throughout the budding yeast genome. In wild-type strains, R-loops were readily detected over the 35S rDNA region, transcribed by Pol I, and over the 5S rDNA, transcribed by Pol III. In strains lacking RNase H activity, R-loops were elevated over other Pol III genes, notably tRNAs, SCR1 and U6 snRNA, and were also associated with the cDNAs of endogenous TY1 retrotransposons, which showed increased rates of mobility to the 5'-flanking regions of tRNA genes. Unexpectedly, R-loops were also associated with mitochondrial genes in the absence of RNase H1, but not of RNase H2. Finally, R-loops were detected on actively transcribed protein-coding genes in the wild-type, particularly over the second exon of spliced ribosomal protein genes

The International Maritime Organization and Oil Pollution in the Mediterranean Sea

Maritime transportation has diametric personalities. The advancement in global maritime transportation of oil products has resulted in commercial advantages. This advancement has simultaneously led to environmental disadvantages, sporadically leaving the marine environment in a detrimental position. “Commercial advantages” and “environmental disadvantages” are apparently two central issues that emanate from maritime transportation. Although the disadvantages cannot concretely outweigh the advantages, the “pollution” aspect has coastal states, environmentalists, marine biologists, and international organizations worrying whether economic gain is worth destroying the pristine environment. However, some environmentalists are optimistic and state that the marine environment has a form of resistance-capacity and time may heal the human-initiated damage leading to the point where nature will reinstate itself to its original status. However, what has changed today is that with the advancement in global maritime transportation, the impacts on the marine environment are no longer small, localized, and reversible. Incidents both accidental and operational in nature have raised serious environmental concerns. The Mediterranean Sea is no exception to this concern. Data reveals that maritime activities in the Mediterranean have increased since the late 1900s and this “increase” will reach a higher plateau by 2018. While no major accidents have been recorded so far, the ubiquity, abundance, and broadness of detected operational spills in the Mediterranean have caught the attention of the International Maritime Organization (IMO). Hence, the Mediterranean Sea is distinguished as a “special area” and the need to control oil transportation has become a dire need in order to save the region from anthropogenic impacts. Similar to many anthropogenic impacts on natural systems, oil pollution is one that, despite widespread recognition of the problem, is still growing and even if stopped immediately will persist in the marine environment for years to come. Scientists have proven that polycyclic aromatic hydrocarbons, a high molecular weight component (compound) of crude oil, are extremely difficult to clean due to its complex structure. The main problem associated with this component is that they cannot be absolutely degraded by bioremediation efforts. Since the rise in the number of maritime transportation is inevitable, to eradicate problems associated with illegal oil discharge, the Mediterranean Sea area has been designated as a “special area.” The question is whether the initiatives of the IMO to establish a “zero discharge policy” are sufficient to control oil pollution in the Mediterranean Sea? This chapter will endeavor to answer that question.https://commons.wmu.se/mer_chapters/1003/thumbnail.jp