Analysis of GeV-band gamma-ray emission from SNR RX J1713.7-3946

RX J1713.7-3946 is the brightest shell-type Supernova remnant (SNR) of the TeV gamma-ray sky. Earlier Fermi-LAT results on low-energy gamma-ray emission suggested that, despite large uncertainties in the background determination, the spectrum is inconsistent with a hadronic origin. We update the GeV-band spectra using improved estimates for the diffuse galactic gamma-ray emission and more than doubled data volume. We further investigate the viability of hadronic emission models for RX J1713.7-3946. We produced a high-resolution map of the diffuse Galactic gamma-ray background corrected for HI self-absorption and used it in the analysis of more than 5~years worth of Fermi-LAT data. We used hydrodynamic scaling relations and a kinetic transport equation to calculate the acceleration and propagation of cosmic-rays in SNR. We then determined spectra of hadronic gamma-ray emission from RX J1713.7-3946, separately for the SNR interior and the cosmic-ray precursor region of the forward shock, and computed flux variations that would allow to test the model with observations. We find that RX J1713.7-3946 is now detected by Fermi-LAT with very high statistical significance, and the source morphology is best described by that seen in the TeV band. The measured spectrum of RX J1713.7-3946 is hard with index gamma=1.53 +/- 0.07, and the integral flux above 500 MeV is F = (5.5 +/- 1.1)e-9 photons/cm^2/s. We demonstrate that scenarios based on hadronic emission from the cosmic-ray precursor region are acceptable for RX J1713.7-3946, and we predict a secular flux increase at a few hundred GeV at the level of around 15% over 10 years, which may be detectable with the upcoming CTA observatory.Comment: 9 pages, accepted for publication in Astronomy & Astrophysic

Strong coupling of a qubit to shot noise

We perform a nonperturbative analysis of a charge qubit in a double quantum dot structure coupled to its detector. We show that strong detector-dot interaction tends to slow down and halt coherent oscillations. The transitions to a classical and a low-temperature quantum overdamping (Zeno) regime are studied. In the latter, the physics of the dissipative phase transition competes with the effective shot noise.Comment: 5 pages, 4 figure

Aktivnost kolinesteraza krvi u radnika eksponiranih antikolinesterazama. Rezultati desetgodišnjeg praćenja

The surveillance of workers exposed to anticholinesterase insecticides during their formulation has shown that the use of protective devices at work and observation of the hygienic and sanitary regulations provide a satisfactory protection and reduce significantly the absorption of anticholinesterase insecticides. Our study has confirmed that a beweekly measurement of cholinesterase activity during a period of intense production is the only practicable method for determining the degree of absorption. With this method one can learn in time whether there are workers at risk, and thus prevent the danger of further ab-sorption. Without exception, the workers showing cho1inergic symptoms had their blood cholinesterase inhibited 50% or more. However, complaints from workers were not always related to cholinesterase inhibition. In agricultural workers exposed to insecticides cholinesterase inhibition rarely exceeded ten per cent. In several individuals who showed inhibition up to 40% subjective complaints were present. It appears that long-term exposure to anticholinesterases had no effect on peripheral blood as revealed by blood cell counts.Kontrola radnika zaposlenih u formulaciji antikolinesteraznih insekticida pokazuje da upotreba propisanih zaštitnih sredstava pri radu i pridržavanje higijenskih i sanitarnih odredaba omogućuje zadovoljavajući stupanj zaštite i značajno smanjuje apsorpciju antikolinesteraznih insekticida. Naša proučavanja potvrđuju da mjerenje aktivnosti kolinesteraze svakog drugog tjedna za vrijeme trajanja intenzivne produkcije pruža jedinu praktičnu mjeru za određivanje stupnja apsorpcije. Na taj način može se na vrijeme uočiti potencijalna opasnost za svakog pojedinog radnika i tako spriječiti opasnost od daljnje apsorpcije. Bez iznimaka, radnici u kojih su se pojavili kohinergični simptomi otrovanja imali su kolinesterazu pune krvi inhibiranu oko ili više od 50%. Međutim. pritužbe radnika nisu uvijek bile u skladu s inhibicijom kolinesteraze. U poljoprivrednih radnika eksponiranih insekticidima u pravilu inhibicija kolinesteraze nije premašila deset posto. U nekoliko osoba kojima je inhibicija kolinesteraze premašila 40% bile su prisutne i subjektivne smetnje. Čini se da dugotrajna ekspozicija antikolinesteraznim spojevima nema učinka na broj krvnih stanica u perifernoj krvi

On neutron number dependence of B(E1;0+ --> 1-) reduced transition probability

A neutron number dependence of the E1 0+ --> 1- reduced transition probability in spherical even--even nuclei is analysed within the Q--phonon approach in the fermionic space to describe the structure of collective states. Microscopic calculations of the E1 0+ --> 1- transition matrix elements are carried out for the Xe isotopes based on the RPA for the ground state wave function. A satisfactory description of the experimental data is obtained.Comment: 8 pages, 4 figure