On the Energy Spectra of GeV/TeV Cosmic Ray Leptons

Recent observations of cosmic ray electrons from several instruments have revealed various degrees of deviation in the measured electron energy distribution from a simple power-law, in a form of an excess around TeV energies. An even more prominent deviation has been observed in the fraction of cosmic ray positrons around 100 GeV energies. In this paper we show that the observed excesses in the electron spectrum may be easily re-produced without invoking any unusual sources other than the general diffuse Galactic components of cosmic rays. The primary physical effect involved is the Klein-Nishina suppression of the electron cooling rate around TeV energies. With a very reasonable choice of the model parameters characterizing the local interstellar medium, we can reproduce the most recent observations by Fermi and HESS experiments. We also find that high positron fraction increasing with energy, as claimed by the PAMELA experiment, cannot be explained in our model with the conservative set of the model parameters. We are able, however, to reproduce the PAMELA results assuming high values of the starlight and interstellar gas densities, which would be more appropriate for vicinities of supernova remnants. A possible solution to this problem may be that cosmic rays undergo most of their interactions near their sources due to the efficient trapping in the far upstream of supernova shocks by self-generated, cosmic ray-driven turbulence.Comment: 31 pages, accepted for publication in ApJ (abstract abridged for arXiv

Diffuse Gamma Rays: Galactic and Extragalactic Diffuse Emission

"Diffuse" gamma rays consist of several components: truly diffuse emission from the interstellar medium, the extragalactic background, whose origin is not firmly established yet, and the contribution from unresolved and faint Galactic point sources. One approach to unravel these components is to study the diffuse emission from the interstellar medium, which traces the interactions of high energy particles with interstellar gas and radiation fields. Because of its origin such emission is potentially able to reveal much about the sources and propagation of cosmic rays. The extragalactic background, if reliably determined, can be used in cosmological and blazar studies. Studying the derived "average" spectrum of faint Galactic sources may be able to give a clue to the nature of the emitting objects.Comment: 32 pages, 28 figures, kapproc.cls. Chapter to the book "Cosmic Gamma-Ray Sources," to be published by Kluwer ASSL Series, Edited by K. S. Cheng and G. E. Romero. More details can be found at http://www.gamma.mpe-garching.mpg.de/~aws/aws.htm

Dyspnea: Effect of Auricular Acupressure in End Stage Lung Cancer Patients, a Pilot Feasibility Study

Introduction: Dyspnea is a debilitating symptom, common in advanced lung cancer patients, and poorly controlled. The National Institutes of Health has promoted the need for research regarding end of life care symptom control. Purpose: Conduct a feasibility study evaluating auricular acupressure effects on dyspnea in hospice lung cancer patients. Theoretical framework: The UCSF School of Nursing Symptom Management Faculty Group\u27s Model for Symptom Management was used for the conceptual framework. The model includes three dimensions: symptom experience, symptom management strategies, and symptom outcomes. The Human Energy Field Theory provided context for using auricular acupressure. Aim: Conduct a pilot study evaluating feasibility and effects of auricular acupressure on dyspnea. Hypotheses: auricular-acupressure seed adhesive use on appropriate points plus standard care (SC) would be more effective than usual care or usual care plus placebo in (1) reducing dyspnea and (2) increasing oxygen saturation. Methods: Both quantitative and qualitative methods. Sample - 11 hospice patients with lung cancer and dyspnea. Procedure - 8 times (Day 1 baseline and post intervention, Days 2 early-late, 3 early-late, 4 early-late follow-ups) dyspnea was measured by the Cancer Dyspnea Scale and oxygen saturation was measured by pulse-oximeter. Qualitative questions were asked on Days 1 and 4. A trained professional administered the acupressure intervention after baseline assessments. Design -The experimental design included 3 conditions with eight measurement points in time. Patients were randomly assigned to one of three treatment conditions: (1) Standard Care; (2) Standard Care with seed adhesive on inappropriate points (placebo); (3) Standard Care with seed adhesive Auricular acupressure on appropriate points. The results were analyzed using analysis of variance (ANOVA). Results: Both quantitative and qualitative analyses supported the presence of acupressure effects with medium to large effects and a significant effect for dyspnea effort. Conclusions: Although difficult to recruit patients to a trial of alternative therapy in advanced disease, it is possible to test such treatments that potentially can improve symptoms in palliative care. Auricular acupressure may help ameliorate dyspnea. There is a continued need for symptom control at end of the life. The role of nursing is central to end of life care

Charter Cities And The Aerotropolis In Colombia

Based on its income per capita, Colombia meets the World Bank criteria for classification as an upper middle income country, but it still has many of the earmarks of a developing country, including its high poverty rate (45%), high infant mortality (16 deaths per 1000 live births), and lower life expectancy (74 years) than most developed countries. The capital city, Bogota, contains one-fifth of Colombia’s population, which is typical of the “urban giantism” of developing countries. Colombia’s income inequality is acute, with the lowest decile of households receiving 0.8% of household incomes, while the highest decile receives 45%. This results in a Gini coefficient of 58 - the ninth highest in the world. The paradox is that while Colombia’s per-capita GDP and GNI indicate that it is an upper-middle income country, its poverty, income inequality, infant mortality rate, and other socioeconomic indicators look very much like those of a low-income country. This raises an interesting question: “How can Colombia continue its development, presumably toward becoming a high-income country, while it is addressing its disproportionate poverty levels and income inequality?” This paper investigates the prospects and challenges of implementing two relatively new ideas in economic development. The first is the use of Paul Romer’s idea of charter cities to enhance economic development in Colombia. Charter cities could be used to create more dynamic enterprise zones than now exist in Colombia. Romer advocates that countries set aside currently uninhabited city-size special reform zones to be charter cities. These cities would have a charter or constitution which specifies the governing rules - good rules (or institutions) - which would be supportive of entrepreneurial activity and a robust business climate. Charter cities could presumably be like a “clean slate” without all the developing-country plethora of rules and regulations that hinder development in established cities such as Cairo and Mumbai. Romer cites the example of Hong Kong as an extraordinarily successful early type of charter city which was governed by different rules for 99 years before it was ceded back to the People’s Republic of China by Great Britain in 1997. The second type of development tool for Colombia explored in this paper is John Kasarda’s “aerotropolis.” An aerotropolis is a city built around an airport. Traditional cities sprang up around existing trade routes along navigable waterways or where road and railroads met and crossed. The twenty-first century equivalent of that, according to Kasarda, is where “highways in the sky” interact with productive facilities on the ground at or near airports to be part of an ever-growing global supply chain. In this paper, some possible locations for charter cities and aerotropolises in Colombia are explored and their economic impact is assessed. The paper concludes that both can assist Colombia in reducing poverty and income inequality, but with certain qualifications. It also suggests that a hybrid of the two, an aerotropolis that is also a charter city, can significantly contribute to Colombia’s economic development

A Broadband Study of the Emission from the Composite Supernova Remnant MSH 11-62

MSH 11-62 (G291.1-0.9) is a composite supernova remnant for which radio and X-ray observations have identified the remnant shell as well as its central pulsar wind nebula. The observations suggest a relatively young system expanding into a low density region. Here we present a study of MSH 11-62 using observations with the Chandra, XMM-Newton, and Fermi observatories, along with radio observations from the Australia Telescope Compact Array (ATCA). We identify a compact X-ray source that appears to be the putative pulsar that powers the nebula, and show that the X-ray spectrum of the nebula bears the signature of synchrotron losses as particles diffuse into the outer nebula. Using data from the Fermi LAT, we identify gamma-ray emission originating from MSH 11-62. With density constraints from the new X-ray measurements of the remnant, we model the evolution of the composite system in order to constrain the properties of the underlying pulsar and the origin of the gamma-ray emission.Comment: 12 Pages, 12 figures. Accepted for publication in the Astrophysical Journa

Radio observational constraints on Galactic 3D-emission models

(Abridged) We constrain simulated all-sky maps in total intensity, linear polarization, and rotation measure (RM) by observations. We test a number of large-scale magnetic field configurations and take the properties of the warm interstellar medium into account. From a comparison of simulated and observed maps we are able to constrain the regular large-scale Galactic magnetic field in the disk and the halo of the Galaxy. The local regular field is 2 microG and the average random field is about 3 microG. The known local excess of synchrotron emission originating either from enhanced CR electrons or random magnetic fields is able to explain the observed high-latitude synchrotron emission. The thermal electron model (NE2001) in conjunction with a proper filling factor accounts for the observed optically thin thermal emission and low frequency absorption by optically thick emission. A coupling factor between thermal electrons and the random magnetic field component is proposed, which in addition to the small filling factor of thermal electrons increases small-scale RM fluctuations and thus accounts for the observed depolarization at 1.4 GHz. We conclude that an axisymmetric magnetic disk field configuration with reversals inside the solar circle fits available observations best. Out of the plane a strong toroidal magnetic field with different signs above and below the plane is needed to account for the observed high-latitude RMs. Our preferred 3D-model fits the observations better than other models over a wide frequency range.Comment: 20 pages, 19 figures, accepted for publication in A&A, for full resolution version see ftp://ftp.mpifr-bonn.mpg.de/outgoing/p098wre/sun-etal.pd

Galactic Magnetic Turbulence from Radio data

Fluctuations in the Galactic synchrotron emission can be traced by the angular power spectrum of radio maps at low multipoles. At frequencies below few GHz, large-scale anisotropies are mainly induced by magnetic field turbulence. By performing an analysis of five radio maps, we extract constraints on turbulence spectral index and halo scale. Results favour a power spectrum significantly flatter than for 3D Kolmogorov-like turbulence, and a thin halo. This can be interpreted as an indication supporting non-conventional models of propagation of cosmic-ray particles in the Galaxy, or as a suggestion of a spectral-index break in the observed magnetic turbulence power spectrum.Comment: 15 pages, 3 figures. v2: discussions and references improved, to appear in Astropart.Phys.

From 10 Kelvin to 10 TeraKelvin: Insights on the Interaction Between Cosmic Rays and Gas in Starbursts

Recent work has both illuminated and mystified our attempts to understand cosmic rays (CRs) in starburst galaxies. I discuss my new research exploring how CRs interact with the ISM in starbursts. Molecular clouds provide targets for CR protons to produce pionic gamma rays and ionization, but those same losses may shield the cloud interiors. In the densest molecular clouds, gamma rays and Al-26 decay can provide ionization, at rates up to those in Milky Way molecular clouds. I then consider the free-free absorption of low frequency radio emission from starbursts, which I argue arises from many small, discrete H II regions rather than from a "uniform slab" of ionized gas, whereas synchrotron emission arises outside them. Finally, noting that the hot superwind gas phase fills most of the volume of starbursts, I suggest that it has turbulent-driven magnetic fields powered by supernovae, and that this phase is where most synchrotron emission arises. I show how such a scenario could explain the far-infrared radio correlation, in context of my previous work. A big issue is that radio and gamma-ray observations imply CRs also must interact with dense gas. Understanding how this happens requires a more advanced understanding of turbulence and CR propagation.Comment: Conference proceedings for "Cosmic-ray induced phenomenology in star-forming environments: Proceedings of the 2nd Session of the Sant Cugat Forum of Astrophysics" (April 16-19, 2012). 16 pages, 5 figure

The seasonal oscillation in sea level

On the basis of all available tide gauge records, bathythermograma, and Nansen bottle casts, we have compiled, on a global scale, monthly departures of recorded and steric sea levels from their annual means. The steric fluctuation is defined in terms of the seasonal fluctuation in specific volume. The results are given in the appendices and in three charts, together with error estimates. In general, the departures are comfortably above the uncertainties introduced by year to year variations and by the effects of local topography...