Studying the Interstellar Medium and the inner region of NPS/Loop 1 with shadow observations toward MBM36

We analyzed data from a shadow observation of the high density molecular cloud MBM36 (l~4{\deg}, b~35{\deg}) with Suzaku. MBM36 is located in a region that emits relatively weakly in the 3/4~keV band, compared to the surrounding NPS/Loop 1 structure and the Galactic Bulge. The contrast between a high and low density targets in the MBM36 area allows one to separate the local and distant contributors to the Soft Diffuse X-ray Background, providing a much better characterization of the individual components compared to single pointing observations. We identify two non-local thermal components, one at kT~0.12 keV and one at kT~0.29keV. The colder component matches well with models of emission from the higher latitude region of the Galactic Bulge. The emission of the warmer component is in agreement with models predicting that the NPS is due to a hypershell from the center of the Milky Way. Geometrical and pressure calculations rule out a nearby bubble as responsible for the emission associate with the NPS. Any Galactic Halo/CircumGalactic Halo emission, if present, is outshined by the other components. We also report an excess emission around 0.9~keV, likely due to an overabundance of NeIX.Comment: 8 pages, 3 figures, approved for publication on Ap

X-Ray Emission from the Warm Hot Intergalactic Medium

The number of detected baryons in the Universe at z<0.5 is much smaller than predicted by standard big bang nucleosynthesis and by the detailed observation of the Lyman alpha forest at red-shift z=2. Hydrodynamical simulations indicate that a large fraction of the baryons today is expected to be in a ``warm-hot'' (10^5-10^7K) filamentary gas, distributed in the intergalactic medium. This gas, if it exists, should be observable only in the soft X-ray and UV bands. Using the predictions of a particular hydrodynamic model, we simulated the expected X-ray flux as a function of energy in the 0.1-2 keV band due to the Warm-Hot Intergalactic Medium (WHIM), and compared it with the flux from local and high red-shift diffuse components. Our results show that as much as 20% of the total diffuse X-ray background (DXB) in the energy range 0.37-0.925keV could be due to X-ray flux from the WHIM, 70% of which comes from filaments at redshift z between 0.1 and 0.6. Simulations done using a FOV of 3', comparable with that of Suzaku and Constellation-X, show that in more than 20% of the observations we expect the WHIM flux to contribute to more than 20% of the DXB. These simulations also show that in about 10% of all the observations a single bright filament in the FOV accounts, alone, for more than 20% of the DXB flux. Red-shifted oxygen lines should be clearly visible in these observations.Comment: 19 pages, 6 figure

A battery-operated, stabilized, high-energy pulsed electron gun for the production of rare gas excimers

We report on the design of a new type of electron gun to be used for experiments of infrared emission spectroscopy of rare gas excimers. It is based on a filament heated by means of a pack of rechargeable batteries floated atop the high-voltage power supply. The filament current is controlled by a feedback circuit including a superluminescent diode decoupled from the high voltage by means of an optical fiber. Our experiment requires that the charge injection is pulsed and constant and stable in time. This electron gun can deliver several tens of nC per pulse of electrons of energy up to $100\,$keV into the sample cell. This new design eliminates ripples in the emission current and ensures up to 12 hrs of stable performance.Comment: 1o pages, 8 figures, to be submitted to Review of Scientific Instrument

Reconstructing the shape of the correlation function

We develop an estimator for the correlation function which, in the ensemble average, returns the shape of the correlation function, even for signals that have significant correlations on the scale of the survey region. Our estimator is general and works in any number of dimensions. We develop versions of the estimator for both diffuse and discrete signals. As an application, we examine Monte Carlo simulations of X-ray background measurements. These include a realistic, spatially-inhomogeneous population of spurious detector events. We discuss applying the estimator to the averaging of correlation functions evaluated on several small fields, and to other cosmological applications.Comment: 10 pages, 5 figures, submitted to ApJS. Methods and results unchanged but text is expanded and significantly reordered in response to refere

New isogenic wild types in N. crassa

New isogenic wild types in N. crass

An experimental apparatus for measuring the Casimir effect at large distances

An experimental set-up for the measurement of the Casimir effect at separations larger than a few microns is presented. The apparatus is based on a mechanical resonator and uses a homodyne detection technique to sense the Casimir force in the plane-parallel configuration. First measurements in the 3-10 micrometer range show an unexpected large force probably due to patch effects.Comment: Proceedings of the workshop On the 60 Years on Casimir Effec

Observed Limits on Charge Exchange Contributions to the Diffuse X-ray Background

We present a high resolution spectrum of the diffuse X-ray background from 0.1 to 1 keV for a ~1 region of the sky centered at l=90, b=+60 using a 36-pixel array of microcalorimeters flown on a sounding rocket. With an energy resolution of 11 eV FWHM below 1 keV, the spectrum's observed line ratios help separate charge exchange contributions originating within the heliosphere from thermal emission of hot gas in the interstellar medium. The X-ray sensitivity below 1 keV was reduced by about a factor of four from contamination that occurred early in the flight, limiting the significance of the results. The observed centroid of helium-like O VII is 568+2-3 eV at 90% confidence. Since the centroid expected for thermal emission is 568.4 eV while for charge exchange is 564.2 eV, thermal emission appears to dominate for this line complex, consistent with much of the high-latitude O VII emission originating in 2-3 x 10^6 K gas in the Galactic halo. On the other hand, the observed ratio of C VI Ly gamma to Ly alpha is 0.3+-0.2. The expected ratios are 0.04 for thermal emission and 0.24 for charge exchange, indicating that charge exchange must contribute strongly to this line and therefore potentially to the rest of the ROSAT R12 band usually associated with 10^6 K emission from the Local Hot Bubble. The limited statistics of this experiment and systematic uncertainties due to the contamination require only >32% thermal emission for O VII and >20% from charge exchange for C VI at the 90% confidence level. An experimental gold coating on the silicon substrate of the array greatly reduced extraneous signals induced on nearby pixels from cosmic rays passing through the substrate, reducing the triggered event rate by a factor of 15 from a previous flight of the instrument.Comment: 14 pages, 7 figures, to be published in Ap

RetinaNet Object Detector based on Analog-to-Spiking Neural Network Conversion

The paper proposes a method to convert a deep learning object detector into an equivalent spiking neural network. The aim is to provide a conversion framework that is not constrained to shallow network structures and classification problems as in state-of-the-art conversion libraries. The results show that models of higher complexity, such as the RetinaNet object detector, can be converted with limited loss in performance.Comment: 5 pages, submitted to ISCMI 2021 conferenc

Lithium Experiment on Solar Neutrinos to Weight the CNO Cycle

The measurement of the flux of beryllium neutrinos with the accuracy of about 10% and CNO neutrinos with the accuracy 30% will enable to find the flux of pp-neutrinos in the source with the accuracy better than 1% using the luminosity constraint. The future experiments on \nu e- scattering will enable to measure with very good accuracy the flux of beryllium and pp-neutrinos on the Earth. The ratio of the flux of pp-neutrinos on the Earth and in the source will enable to find with very good accuracy a mixing angle theta solar. Lithium detector has high sensitivity to CNO neutrinos and can find the contribution of CNO cycle to the energy generated in the Sun. This will be a stringent test of the theory of stellar evolution and combined with other experiments will provide a precise determination of the flux of pp-neutrinos in the source and a mixing angle theta solar. The work on the development of the technology of lithium experiment is now in progress.Comment: Minor corrections, one reference added, 11 pages, 2 figures, talk given at NANP 2003, Dubna, Russia, June 200