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Related papers: Seeking celestial Positronium with an OH-suppresse…

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The Transient Gamma Ray Spectrometer (TGRS) on board the WIND spacecraft has spent most of the interval 1995-1997 in a high-altitude orbit where gamma-ray backgrounds are low. Its high-resolution Ge spectrometer is thus able to detect weak…

Three periastron passages of the PSR B1259$-$63/LS 2883 binary system, consisting of a 48 ms rotation-powered pulsar and a $\sim30$ M$_{\odot}$ Be star, have been observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space…

High Energy Astrophysical Phenomena · Physics 2018-08-15 T. J. Johnson , K. S. Wood , M. Kerr , R. H. D. Corbet , C. C. Cheung , P. S. Ray , N. Omodei

Hydrides represent the first steps of interstellar chemistry. Sulfanylium (SH$^+$), in particular, is a key tracer of energetic processes. We used ALMA and the IRAM 30 m telescope to search for the lowest frequency rotational lines of…

High-resolution optical spectra (UES/WHT) of the extreme metal-poor post-AGB star HR4049 were obtained at four different orbital phases. The spectra cover the wavelength region from 3650ang to 10850ang at a resolution of R=5.2x10^4. These…

We report on novel observations of HAT-P-1 aimed at constraining the optical transmission spectrum of the atmosphere of its transiting Hot-Jupiter exoplanet. Ground-based differential spectrophotometry was performed over two transit windows…

Earth and Planetary Astrophysics · Physics 2015-09-23 M. Montalto , N. Iro , N. C. Santos , S. Desidera , J. H. C. Martins , P. Figueira , R. Alonso , .

We have searched for absorption in several common atomic species due to the atmosphere or exosphere of the transiting extrasolar planet HD 209458b, using high precision optical spectra obtained with the Subaru High Dispersion Spectrograph…

In living organisms the positron-electron annihilation (occurring during the PET imaging) proceeds in about 30% via creation of a metastable ortho-positronium atom. In the tissue, due to the pick-off and conversion processes, over 98% of…

We investigate the limit of X-ray detection at room temperature on rare-earth molecular films using lanthanum and a pyridine-based dicarboxamide organic linker as a model system. Synchrotron X-ray scanning tunneling microscopy is used to…

A precision measurement by AMS-02 of the positron fraction in primary cosmic rays is presented on this proceeding. Over the last two decades, there has been a strong interest in the cosmic ray positron fraction which exhibit an excess of…

High Energy Astrophysical Phenomena · Physics 2017-01-02 Sami Caroff

Highly polarized QSOs discovered in the Two-Micron All Sky Survey (2MASS) have been observed to determine the source(s) of optical polarization in this near-infrared color-selected sample. Broad emission lines are observed in the polarized…

Astrophysics · Physics 2009-11-07 Paul S. Smith , Gary D. Schmidt , Dean C. Hines , Craig B. Foltz

Physics beyond the Standard Model predicts the possible existence of new particles that can be searched at the low energy frontier in the sub-eV range. The OSQAR photon regeneration experiment looks for "Light Shining through a Wall" from…

Positronium is an ideal system for the research of the bound state QED. The hyperfine splitting of positronium (Ps-HFS: about 203 GHz) is sensitive to new physics beyond the Standard Model via a vacuum oscillation between an ortho-Ps and a…

High Energy Physics - Experiment · Physics 2014-11-21 T Suehara , A Miyazaki , A Ishida , T Namba , S Asai , T Kobayashi , H Saito , M Yoshida , T Idehara , I Ogawa , S Kobayashi , Y Urushizaki , S Sabchevski

We report on measurements of visible extinction spectra of semicontinuous silver nanoshells grown on colloidal silica spheres. We find that thin, fractal shells below the percolation threshold exhibit geometrically tunable plasmon…

Optics · Physics 2009-11-11 Charles A. Rohde , Keisuke Hasegawa , Miriam Deutsch

We measure the optical spectrum of the Diffuse Galactic Light (DGL) -- the local Milky Way in reflection -- using 92,000 blank-sky spectra from the Sloan Digital Sky Survey (SDSS). We correlate the SDSS optical intensity in regions of blank…

Astrophysics of Galaxies · Physics 2011-12-23 Timothy D. Brandt , Bruce T. Draine

The James Webb Space Telescope (JWST) has enabled us to uncover faint galaxies and active galactic nuclei (AGNs) in the early universe. Taking advantage of the unique filter combination used in the Cosmic Evolution Early Release Science…

The H$\alpha$ and H$\beta$ line profiles of the symbiotic star AG Peg observed on 1998 September (phase $\phi$ = 10.24), display the top narrow double Gaussian and bottom broad (FWHM of 200 -- 400 kms$^{-1}$) components. The…

Solar and Stellar Astrophysics · Physics 2018-02-02 Seong-Jae Lee , Siek Hyung

Results of Positron Annihilation Lifetime Spectroscopy (PALS) and microscopic studies on simple microorganisms: brewing yeasts are presented. Lifetime of ortho - positronium (o-Ps) were found to change from 2.4 to 2.9 ns (longer lived…

We present orbit-resolved spectroscopic and photometric observations of the polar ST LMi during its recent low and high states. In the low state spectra, we report the presence of blue and red satellites to the H-alpha emission line; the…

Astrophysics · Physics 2008-11-26 S. Kafka , S. B. Howell , R. K. Honeycutt , J. W. Robertson

Nonlinear optical processes of spatially structured light, including optical vortex and vector optical fields, have stimulated a lot of interesting physical effects and found a variety of important applications ranging from optical imaging…