4 research outputs found
Measurement of the Cosmic Ray e(+)+e(-) Spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope
Designed as a high-sensitivity gamma-ray observatory, the Fermi Large Area Telescope is also an electron detector with a large acceptance exceeding 2 m2 sr at 300 GeV. Building on the gamma-ray analysis, we have developed an efficient electron detection strategy which provides sufficient background rejection for measurement of the steeply falling electron spectrum up to 1 TeV. Our high precision data show that the electron spectrum falls with energy as E-3.0 and does not exhibit prominent spectral features. Interpretations in terms of a conventional diffusive model as well as a potential local extra component are briefly discussed
beta decay of semi-magic Cd-130: Revision and extension of the level scheme of In-130
The beta decay of the semi-magic nucleus Cd-130 has been studied at the
RIBF facility at the RIKEN Nishina Center. The high statistics of the
present experiment allowed for a revision of the established level
scheme of In-130 and the observation of additional beta feeding to high-
lying core-excited states in In-130. The experimental results are
compared to shell-model calculations employing a model space consisting
of the full major N = 50-82 neutron and Z = 28-50 proton shells and the
NA-14 interaction, and good agreement is found
Fermi establishes classical novae as a distinct class of gamma-ray sources
A classical nova results from runaway thermonuclear explosions on the surface of a white dwarf that accretes matter from a low-mass main-sequence stellar companion. In 2012 and 2013, three novae were detected in γ rays and stood in contrast to the first γ-ray-detected nova V407 Cygni 2010, which belongs to a rare class of symbiotic binary systems. Despite likely differences in the compositions and masses of their white dwarf progenitors, the three classical novae are similarly characterized as soft-spectrum transient γ-ray sources detected over 2- to 3-week durations. The γ-ray detections point to unexpected high-energy particle acceleration processes linked to the mass ejection from thermonuclear explosions in an unanticipated class of Galactic γ-ray sources