911 research outputs found
GeV Analysis of Mixed Morphology Supernova Remnants Interacting with Molecular Clouds
The first remnants detected by the Fermi Gamma-ray Space Telescope were of
the type of mixed-morphology supernova remnants interacting with molecular
clouds. In this paper we are presenting preliminary results of the gamma-ray
analysis of 4 selected mixed morphology remnants, G359.1-0.5, G337.8-0.1,
G001.0-0.1, and G346.6-0.2, as well as G349.7+0.2, in the 0.2 - 300 GeV energy
range from the data collected by Fermi Gamma-ray Space Telescope for 3 years.
G359.1-0.5, G337.8-0.1, and G349.7+0.2 were all detected with significances
above 5 sigma. The excess distribution of G359.1-0.5 shows extended gamma-ray
emission, which coincides with the TeV gamma-ray source HESS J1745-303.
G337.8-0.1 also shows an extended nature.Comment: High Energy Gamma-Ray Astronomy: 5th International Meeting on High
Energy Gamma-Ray Astronom
Pervasive Displays Research: What's Next?
Reports on the 7th ACM International Symposium on Pervasive Displays that took place from June 6-8 in Munich, Germany
Origin of gamma-ray emission in the shell of Cassiopeia A
Non-thermal X-ray emission from the shell of Cassiopeia A (Cas A) has been an
interesting subject of study, as it provides information about relativistic
electrons and their acceleration mechanisms in the shocks. Chandra X-ray
observatory revealed the detailed spectral and spatial structure of this SNR in
X-rays. The spectral analysis of Chandra X-ray data of Cas A shows unequal flux
levels for different regions of the shell, which can be attributed to different
magnetic fields in those regions. Additionally, the GeV gamma-ray emission
observed by Large Area Telescope on board Fermi Gamma Ray Space Telescope
showed that the hadronic processes are dominating in Cas A, a clear signature
of acceleration of protons. In this paper we aim to explain the GeV-TeV
gamma-ray data in the context of both leptonic and hadronic scenario. We
modeled the multi-wavelength spectrum of Cas A. We use synchrotron emission
process to explain the observed non-thermal X-ray fluxes from different regions
of the shell. These result in estimation of the model parameters, which are
then used to explain TeV gamma-ray emission spectrum. We also use hadronic
scenario to explain both GeV and TeV fluxes simultaneously. We show that a
leptonic model alone cannot explain the GeV-TeV data. Therefore, we need to
invoke a hadronic model to explain the observed GeV-TeV fluxes. We found that
although pure hadronic model is able to explain the GeV-TeV data, a
lepto-hadronic model provides the best fit to the data.Comment: Accepted in A&
Searching for Overionized Plasma in the Gamma-ray Emitting Supernova Remnant G349.70.2
G349.70.2 is a supernova remnant (SNR) expanding in a dense medium of
molecular clouds and interacting with clumps of molecular material emitting
gamma rays. We analyzed the gamma-ray data of Large Area Telescope on board
Fermi Gamma Ray Space Telescope and detected G349.70.2 in the energy range
of 0.2300 GeV with a significance of 13 showing no extended
morphology. Modeling of the gamma-ray spectrum revealed that the GeV gamma-ray
emission dominantly originates from the decay of neutral pions, where the
protons follow a broken power-law distribution with a spectral break at
12 GeV. To search for features of radiative recombination continua in the
eastern and western regions of the remnant, we analyzed the Suzaku data of
G349.70.2 and found no evidence for overionized plasma. In this paper we
discuss possible scenarios to explain the hadronic gamma-ray emission in
G349.70.2 and the mixed morphology nature of this SNR.Comment: 10 pages, 7 figures; accepted by ApJ. arXiv admin note: text overlap
with arXiv:1406.217
Flowing bodies: Exploring the micro and macro scales of bodily interactions with urban media installations
In this paper we investigate human interactions with urban media installations by adopting two scales of analysis: the body scale (micro) and the city scale (macro). This twofold approach allows us to better understand the relationships between the design properties of outdoor installations and the urban spatial layout around them. We conducted in-the-wild studies of two urban media installations, one consisting of fixed components, and the other of movable components, which were deployed in different places and encouraged different types of whole-body interaction. We provide a detailed account of the micro and macro levels of interactions, based on observational and qualitative explorations. Our studies reveal that the urban spatial layout is a key element in defining the interactions and encounters around outdoor interfaces, and therefore it needs to inform the design process from the outset
Recombining Plasma in the Gamma-ray Emitting Mixed-Morphology Supernova Remnant 3C 391
A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs)
interacting with molecular clouds (MC) has been discovered as strong GeV
gamma-ray emitters by Large Area Telescope on board Fermi Gamma Ray Space
Telescope (Fermi-LAT). The recent observations of the Suzaku X-ray satellite
have revealed that some of these interacting gamma-ray emitting SNRs, such as
IC443, W49B, W44, and G359.1-0.5, have overionized plasmas. 3C 391 (G31.9+0.0)
is another Galactic MM SNR interacting with MC. It was observed in GeV gamma
rays by Fermi-LAT as well as in the 0.3 10.0 keV X-ray band by Suzaku. In
this work, 3C 391 was detected in GeV gamma rays with a significance of
18 and we showed that the GeV emission is point-like in nature. The
GeV gamma-ray spectrum was shown to be best explained by the decay of neutral
pions assuming that the protons follow a broken power-law distribution. We
revealed radiative recombination structures of silicon and sulfur from 3C 391
using Suzaku data. In this paper we discuss the possible origin of this type of
radiative plasma and hadronic gamma rays.Comment: 10 pages, 7 figures; accepted by Ap
Holography in 4D (Super) Higher Spin Theories and a Test via Cubic Scalar Couplings
The correspondences proposed previously between higher spin gauge theories
and free singleton field theories were recently extended into a more complete
picture by Klebanov and Polyakov in the case of the minimal bosonic theory in
D=4 to include the strongly coupled fixed point of the 3d O(N) vector model.
Here we propose an N=1 supersymmetric version of this picture. We also
elaborate on the role of parity in constraining the bulk interactions, and in
distinguishing two minimal bosonic models obtained as two different consistent
truncations of the minimal N=1 model that retain the scalar or the
pseudo-scalar field. We refer to these models as the Type A and Type B models,
respectively, and conjecture that the latter is holographically dual to the 3d
Gross-Neveu model. In the case of the Type A model, we show the vanishing of
the three-scalar amplitude with regular boundary conditions. This agrees with
the O(N) vector model computation of Petkou, thereby providing a non-trivial
test of the Klebanov-Polyakov conjecture.Comment: 30p
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