10,455 research outputs found
Supersymmetric Particle Production at HERA
In the framework of the minimal supersymmetric standard model and the
-parity breaking model, we investigate various production processes of the
supersymmetric partner at HERA energies. Our emphasis is paid upon the scalar
top quark, the partner of top quark, characterized by its lighter mass than the
top quark and other scalar quarks in a model. We propose experimentally
feasible approaches to search for clean signals of the stop from either its
production or decay processes.Comment: 30 pages, LaTeX, 21 figures available upon reques
Technique for microswitch manufacture
A five-step technique for microswitch manufacture is described: (1) A clad board is inlaid with a precious metal and the board is pressed. (2) One end of the fixed contact containing a precious metal inlay section is curved, and this edge of the precious metal inlay section becomes a fixed contact. (3) Inserts are formed in the unit body and terminal strips are placed through the top and bottom of the base and held. (4) The unit body is held by the base and the sequential contact strips are cut off. (5) Movable stripes are attached to the support of the terminal strips on the movable side and movable contacts are placed opposite the fixed contacts
A 1000 AU Scale Molecular Outflow Driven by a Protostar with an age of <4000 Years
To shed light on the early phase of a low-mass protostar formation process,
we conducted interferometric observations towards a protostar GF9-2 using the
CARMA and SMA. The observations have been carried out in the CO J=3-2 line and
in the continuum emission at the wavelengths of 3 mm, 1 mm and 850 micron. All
the continuum images detected a single point-like source with a radius of
250+/-80 AU at the center of the previously known ~3 Msun molecular cloud core.
A compact emission is detected towards the object at the Spitzer MIPS and IRAC
bands as well as the four bands at the WISE. Our spectroscopic imaging of the
CO line revealed that the continuum source is driving a 1000 AU scale molecular
outflow, including a pair of lobes where a collimated "higher" velocity red
lobe exists inside a poorly collimated "lower" velocity red lobe. These lobes
are rather young and the least powerful ones so far detected. A protostellar
mass of M~<0.06 Msun was estimated using an upper limit of the protostellar age
of (4+/-1)x10^3 yrs and an inferred non-spherical steady mass accretion rate of
~10^{-5} Msun/yr. Together with results from an SED analysis, we discuss that
the outflow system is driven by a protostar whose surface temperature
of~3,000K, and that the natal cloud core is being dispersed by the outflow.Comment: 27 pages, 14 figures, accepted for publication in Astrophysical
Journa
The Initial Conditions for Gravitational Collapse of a Core: An Extremely Young Low-Mass Class 0 Protostar GF9-2
We present a study of the natal core harboring the class 0 protostar GF9-2 in
the filamentary dark cloud GF 9 (d = 200 pc). GF9-2 stands unique in the sense
that it shows H2O maser emission, a clear signpost of protostar formation,
whereas it does not have a high-velocity large-scale molecular outflow
evidenced by our deep search for CO wing emission. These facts indicate that
GF9-2 core is early enough after star formation so that it still retains some
information of initial conditions for collapse. Our 350 um dust continuum
emission image revealed the presence of a protostellar envelope in the center
of a molecular core. The mass of the envelope is ~0.6 Msun from the 350 um flux
density, while LTE mass of the core is ~3 Msun from moleuclar line
observations. Combining visibility data from the OVRO mm-array and the 45m
telescope, we found that the core has a radial density profile of
for 0.003 < r/pc < 0.08 region. Molecular line data
analysis revealed that the velocity width of the core gas increases
inward,while the outermost region maintains a velocity dispersion of a few
times of the ambient sound speed. The broadened velocity width can be
interpreted as infall. Thus, the collapse in GF9-2 is likely to be described by
an extension of the Larson-Penston solution for the period after formation of a
central star. We derived the current mass accretion rate of ~3E-05 Msun/year
from infall velocity of ~ 0.3 km/s at r~ 7000 AU. All results suggest that
GF9-2 core has been undergoing gravitational collapse for ~ 5000 years since
the formation of central protostar(s), and that the unstable state initiated
the collapse ~2E+05 years (the free-fall time) ago.Comment: ApJ Accepted. The preprint including figures with the original
quality is available at http://subarutelescope.org/staff/rsf/publication.htm
Rotating dust solutions of Einstein's equations with 3-dimensional symmetry groups, Part 3: All Killing fields linearly independent of u^{\alpha} and w^{\alpha}
This is the third and last part of a series of 3 papers. Using the same
method and the same coordinates as in parts 1 and 2, rotating dust solutions of
Einstein's equations are investigated that possess 3-dimensional symmetry
groups, under the assumption that each of the Killing vectors is linearly
independent of velocity and rotation at every point
of the spacetime region under consideration. The Killing fields are found and
the Killing equations are solved for the components of the metric tensor in
every case that arises. No progress was made with the Einstein equations in any
of the cases, and no previously known solutions were identified. A brief
overview of literature on solutions with rotating sources is given.Comment: One missing piece, signaled after eq. (10.7), is added after (10.21).
List of corrections: In (3.7) wrong subscript in vorticity; In (3.10) wrong
subscript in last term of g_{23}; In (4.23) wrong formulae for g_{12} and
g_{22}; In (7.17) missing factor in velocity; In (7.18) one wrong factor in
g_{22}; In (10.9) factor in vorticity; In (10.15) - (10.20) y_0 = 0; In
(10.20) wrong second term in y. The rewriting typos did not influence result
Phytohaemagglutinin on maternal and umbilical leukocytes
Almost all the umbilical lymphocytes showed more extensive blast cell formation
than that of their mother's lymphocytes with PHA. Pathological conditions of mother in pregnancy and labor such as anemia, gestational toxicosis,
difficult labor and asphyxia of babies, inhibited the normal response of both maternal and umbilical lymphocytes to PHA.</p
Low-Mass Star Forming Cores in the GF9 Filament
We carried out an unbiased mapping survey of dense molecular cloud cores
traced by the NH3 (1,1) and (2,2) inversion lines in the GF9 filament which
contains an extremely young low-mass protostar GF9-2 (Furuya et al. 2006, ApJ,
653, 1369). The survey was conducted using the Nobeyama 45m telescope over a
region of ~1.5 deg with an angular resolution of 73". The large-scale map
revealed that the filament contains at least 7 dense cores, as well as 3
possible ones, located at regular intervals of ~0.9 pc. Our analysis shows that
these cores have kinetic temperatures of 10 K and LTE-masses of 1.8
-- 8.2 Msun, making them typical sites of low-mass star formation. All the
identified cores are likely to be gravitationally unstable because their
LTE-masses are larger than their virial masses. Since the LTE-masses and
separations of the cores are consistent with the Jeans masses and lengths,
respectively, for the low-density ambient gas, we argue that the identified
cores have formed via the gravitational fragmentation of the natal filamentary
cloud.Comment: accepted by pas
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