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Antimatter in the Universe: constraints from gamma-ray astronomy
von Ballmoos, Peter
We review gamma-ray observations that constrain antimatter - both baryonic and leptonic - in the Universe. Antimatter is probed through ordinary matter, with the resulting annihilation gamma-rays providing indirect evidence for its presence. Although it is generally accepted that equal amounts of matter and antimatter have been produced in the Big…
Modeling Active Region Transient Brightenings Observed with X-Ray Telescope as Multi-stranded Loops
McKenzie, David E.; Donachie, Martin; Kobelski, Adam R.
Strong evidence exists that coronal loops as observed in extreme ultraviolet and soft X-rays may not be monolithic isotropic structures, but can often be more accurately modeled as bundles of independent strands. Modeling the observed active region transient brightenings (ARTBs) within this framework allows for the exploration of the energetic ram…
Herschel SPIRE FTS telescope model correction
Valtchanov, Ivan; Hopwood, Rosalind; Lu, Nanyao +8 more
Emission from the Herschel telescope is the dominant source of radiation for the majority of SPIRE Fourier transform spectrometer (FTS) observations, despite the exceptionally low emissivity of the primary and secondary mirrors. Accurate modelling and removal of the telescope contribution is, therefore, an important and challenging aspect of FTS c…
Fe-rich Ejecta in the Supernova Remnant G352.7-0.1 with Suzaku
Sezer, A.; Gök, F.
In this work, we present results from a ~201.6 ks observation of G352.7-0.1 using the X-ray Imaging Spectrometer on board Suzaku X-ray Observatory. The X-ray emission from the remnant is well described by two-temperature thermal models of non-equilibrium ionization with variable abundances with a column density of N H ~ 3.3 × 1022<…
Earth occultation imaging of the low energy gamma-ray sky with GBM
Wilson-Hodge, C. A.; Camero-Arranz, A.; Rodi, J. +5 more
Aims: The Earth Occultation Technique (EOT) has been applied to Fermi's Gamma-ray Burst Monitor (GBM) to perform all-sky monitoring for a predetermined catalog of hard X-ray/soft γ-ray sources. In order to search for sources not in the catalog, thus completing the catalog and reducing a source of systematic error in EOT, an imaging method has…
The Role of Magnetic Fields in Transient Seismic Emission Driven by Atmospheric Heating in Flares
Lindsey, C.; Hudson, H. S.; Donea, A. -C. +1 more
Transient seismic emission in flares remains largely mysterious. Its discoverers proposed that seismic transients are driven by impulsive heating of the flaring chromosphere. Simulations of such heating show strong shocks, but these are damped by heavy radiative losses as they proceed downward. Because compression of the gas the shock enters both …
The orbit of transneptunian binary Manwë and Thorondor and their upcoming mutual events
Grundy, W. M.; Noll, K. S.; Benecchi, S. D. +1 more
A new Hubble Space Telescope observation of the 7:4 resonant transneptunian binary system (385446) Manwë has shown that, of two previously reported solutions for the orbit of its satellite Thorondor, the prograde one is correct. The orbit has a period of 110.18 ± 0.02 days, semimajor axis of 6670 ± 40 km, and an eccentricity of 0.563 ± 0.007. It w…
Eastern Olympus Mons Basal Scarp: Structural and mechanical evidence for large-scale slope instability
Weller, M. B.; McGovern, P. J.; Fournier, T. +1 more
The expression of the Eastern Olympus Mons Basal Scarp (EOMBS) is seemingly unique along the edifice. It exhibits two slope-parallel structures: a nearly 100 km long upslope extensional normal fault system and a downslope contractional wrinkle ridge network, a combination that is found nowhere else on Olympus Mons. Through structural mapping and n…
Disk emission and atmospheric absorption lines in black hole candidate 4U 1630-472
Różańska, A.; Madej, J.; Bagińska, P. +2 more
Context. We analyzed Suzaku data of the black hole candidate 4U 1630-472 when it was in the high/soft state. The source, known for X-ray outbursts and for absorption dips, has an X-ray continuum spectrum that is interpreted correctly as emission from an accretion disk. Additionally, two absorption lines from He and H-like iron have been clearly de…
Early-type Galaxies at Intermediate Redshift Observed with Hubble Space Telescope WFC3: Perspectives on Recent Star Formation
Hathi, Nimish P.; Rutkowski, Michael J.; Windhorst, Rogier A. +7 more
We present an analysis of the stellar populations of 102 visually selected early-type galaxies (ETGs) with spectroscopic redshifts (0.35 lsim z lsim 1.5) from observations in the Early Release Science program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). We fit one- and two-component synthetic stellar models to the ETGs …