6,195 research outputs found
A Neutrino-Factory Muon Storage Ring to Provide Beams for Multiple Detectors Around the World
We briefly discuss the physics motivation for a neutrino factory with varying
baseline distances of about 1000 to 9000 km. We describe the amount of non
planarity of the storage ring required to service three or four detectors at
once. A novel bowtie storage ring is described that could in part provide these
beams; a preliminary lattice design is given. We give the space angles between
the various detector locations and possible sites for neutrino factories.
Finally we describe detectors at the Gran Sasso Laboratory and at a new
laboratory near Carlsbad, NM to observe the neutrino interactions with wrong
sign leptons.Comment: 8 pages. Presented at the 5th Int. Conf. sponsored by UCLA on the
Physics Potential and Develoment of mu^+mu^- Colliders (San Francisco,
December 15-17, 1999) and to be published in the Proceedings by AI
An Unbiased Survey for Molecular Clouds in the Southern Galactic Warp
We have made an unbiased survey for molecular clouds in the Galactic Warp.
This survey, covering an area of 56 square degrees at l = 252 deg to 266 deg
and b = -5 deg to -1 deg, has revealed 70 molecular clouds, while only 6 clouds
were previously known in the region. The number of molecular clouds is, then,
an order of magnitude greater than previously known in this sector at R > 14.5
kpc. The mass of the clouds is in a range from 7.8x10(2) Mo to 8.4x10(4) Mo,
significantly less than the most massive giant molecular clouds in the inner
disk, ~10(6) Mo, while the cloud mass spectrum characterized by a power law is
basically similar to other parts of the Galaxy. The X factor, N(H2)/Wco(12CO),
derived from the molecular clouds in the Warp is estimated to be 3.5(+/-1.8)
times larger than that in the inner disk. The total molecular mass in the Warp
is estimated as 7.3x10(5) Mo, and total mass in the far-outer Galaxy (R > 14.5
kpc) can be estimated as 2x10(7) Mo. The spatial correlation between the CO and
HI distribution appears fairly good, and the mass of the molecular gas is about
1% of that of the atomic gas in the far-outer Galaxy. This ratio is similar to
that in the interarm but is ten times smaller than those of the spiral arms.
Only 6 of the 70 Warp clouds show signs of star formation at the IRAS
sensitivity and star formation efficiency for high-mass stars in the Warp is
found to be smaller than those in other molecular clouds in the Galaxy.Comment: 29 pages, including 12 (pages of) figures, accepted for PASJ, and
will be published in PASJ Vol.57, No.6. Tables and color-figures are
available on-line:
http://www.a.phys.nagoya-u.ac.jp/~masa/study/nakagawa_etal2005_warp.pd
Recombining Plasma & Gamma-ray Emission in the Mixed-morphology Supernova Remnant 3C 400.2
3C 400.2 belongs to the mixed morphology supernova remnant class, showing
center-filled X-ray and shell-like radio morphology. We present a study of 3C
400.2 with archival Suzaku and Fermi-LAT observations. We find recombining
plasma (RP) in the Suzaku spectra of north-east and south-east regions. The
spectra of these regions are well described by two-component thermal plasma
models: The hard component is in RP, while the soft component is in collisional
ionization equilibrium (CIE) conditions. The RP has enhanced abundances
indicating that the X-ray emission has an ejecta origin, while the CIE has
solar abundances associated with the interstellar material. The X-ray spectra
of north-west and south-west regions are best fitted by a two-component thermal
plasma model: an ionizing and a CIE plasma. We have detected GeV gamma-ray
emission from 3C 400.2 at the level of 5 assuming a point-like
source model with a power-law (PL) type spectrum. We have also detected a new
GeV source at the level of 13 assuming a Gaussian extension model
with a PL type spectrum in the neighborhood of the SNR. We report the analysis
results of 3C 400.2 and the new extended gamma-ray source and discuss the
nature of gamma-ray emission of 3C 400.2 in the context of existing NANTEN CO
data, DRAO HI data, and the Suzaku X-ray analysis results.Comment: Accepted to be published in the Astrophysical Journa
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