251 research outputs found
Jet collimation and acceleration in the giant radio galaxy NGC 315
We study the collimation and acceleration of the jets in the nearby giant
radio galaxy NGC 315, using multifrequency Very Long Baseline Array
observations and archival High Sensitivity Array and Very Large Array data. We
find that the jet geometry transitions from a semi-parabolic shape into a
conical/hyperbolic shape at a distance of gravitational radii. We
constrain the frequency-dependent position of the core, from which we locate
the jet base. The jet collimation profile in the parabolic region is in good
agreement with the steady axisymmetric force-free electrodynamic solution for
the outermost poloidal magnetic field line anchored to the black hole event
horizon on the equatorial plane, similar to the nearby radio galaxies M87 and
NGC 6251. The velocity field derived from the asymmetry in brightness between
the jet and counterjet shows gradual acceleration up to the bulk Lorentz factor
of in the region where the jet collimation occurs, confirming
the presence of the jet acceleration and collimation zone. These results
suggest that the jets are collimated by the pressure of the surrounding medium
and accelerated by converting Poynting flux to kinetic energy flux. We discover
limb-brightening of the jet in a limited distance range where the angular
resolution of our data is sufficient to resolve the jet transverse structure.
This indicates that either the jet has a stratified velocity field of
fast-inner and slow-outer layers or the particle acceleration process is more
efficient in the outer layer due to the interaction with the surroundings on
pc-scales.Comment: 32 pages, 18 figures, 5 tables, accepted for publication in Ap
Alkane-degrading bacteria and heavy metals from the Nakhodka oil spill-polluted seashores in the Sea of Japan after five years of bioremediation
Graduate School of Natural Science and Technology, Kanazawa UniversityDepartment of Earth Sciences, Faculty of Science, Kanazawa UniversityDepartment of Earth Sciences, Faculty of Science, Kanazawa UniversityOcean Research Institute, University of TokyoThis paper describes the isolation of alkane-degrading bacteria from the Nakhodka oil spill-polluted seashores in the Sea of Japan. Seven representative strains were identified using 16S rDNA sequence analysis as Bacillus spp., Pseudomonas sp., and Paracoccus spp. All bacterial strains showed their ability to grow well on aliphatic hydrocarbons, but not on aromatic hydrocarbons. In addition, elemental levels in heavy oil showed wide ranges in all the heavy oil samples consisting of Si, S, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Pb. Compounds of Si, S, and Cr were observed at high levels, while those of Ti, Mn, Fe, Co, Ni, Cu, Zn, and Pb were observed at low levels. Of all heavy metals, Co appeared to be toxic for all bacterial growth at concentrations of >1 ppm, while the presence of Ti, Cr, and Cu at 0.01 to 10 ppm were found not to inhibit growth of all bacterial strains. It is suspected that the presence of heavy metals may have a significant effect on the composition of the bacterial community, (i.e., alkane-degrading bacterial isolates), as well as on the biodegradative processes of the Nakhodka oil spill during the 5-year bioremediation
Collimation, Acceleration and Recollimation Shock in the Jet of Gamma-Ray-emitting Radio-Loud Narrow-Line Seyfert 1 Galaxy 1H 0323+342
We investigated the detailed radio structure of the jet of 1H 0323+342 using
high-resolution multi-frequency Very Long Baseline Array observations. This
source is known as the nearest -ray emitting radio-loud narrow-line
Seyfert 1 (NLS1) galaxy. We discovered that the morphology of the inner jet is
well characterized by a parabolic shape, indicating the jet being continuously
collimated near the jet base. On the other hand, we found that the jet expands
more rapidly at larger scales, resulting in a conical-like shape. The location
of the "collimation break" is coincident with a bright quasi-stationary feature
at 7 mas from core (corresponding to a deprojected distance of the order of
100pc), where the jet width locally contracts together with highly
polarized signals, suggesting a recollimation shock. We found that the
collimation region is coincident with the region where the jet speed gradually
accelerates, suggesting the coexistence of the jet acceleration and collimation
zone, ending up with the recollimation shock, which could be a potential site
of high-energy -ray flares detected by the Fermi-LAT. Remarkably, these
observational features of the 1H 0323+342 jet are overall very similar to those
of the nearby radio galaxy M87 and HST-1 as well as some blazars, suggesting
that a common jet formation mechanism might be at work. Based on the similarity
of the jet profile between the two sources, we also briefly discuss the mass of
the central black hole of 1H 0323+342, which is also still highly controversial
on this source and NLS1s in general.Comment: Accepted for publication in ApJ. 15pages, 9 figure
Laparoscopic Hepatectomy for the Patient with Hemophilia A with High Titer Factor VIII Inhibitor
We present the first case of laparoscopic left lateral segmentectomy for hepatocellular carcinoma (HCC) in a patient with hemophilia A, acquired hepatitis C, and high-titer factor VIII inhibitor, which was confirmed by preoperative diagnosis. He underwent laparoscopic left lateral segmentectomy with the administration of recombinant activated factor VII. Surgery could be performed with reduced intraoperative hemorrhage. He experienced postoperative intra-abdominal wall hemorrhage, which was successfully managed with red cell concentrates transfusion and administration of recombinant activated factor VII. Laparoscopic hepatectomy can be applied for hemophilia patients with high titer inhibitors
Parabolic Jets from the Spinning Black Hole in M87
The M87 jet is extensively examined by utilizing general relativistic
magnetohydrodynamic (GRMHD) simulations as well as the steady axisymmetric
force-free electrodynamic (FFE) solution. Quasi-steady funnel jets are obtained
in GRMHD simulations up to the scale of gravitational radius
() for various black hole (BH) spins. As is known, the funnel edge
is approximately determined by the following equipartitions; i) the magnetic
and rest-mass energy densities and ii) the gas and magnetic pressures. Our
numerical results give an additional factor that they follow the outermost
parabolic streamline of the FFE solution, which is anchored to the event
horizon on the equatorial plane. We also identify the matter dominated,
non-relativistic corona/wind play a dynamical role in shaping the funnel jet
into the parabolic geometry. We confirm a quantitative overlap between the
outermost parabolic streamline of the FFE jet and the edge of jet sheath in
VLBI observations at -, suggesting that the
M87 jet is likely powered by the spinning BH. Our GRMHD simulations also
indicate a lateral stratification of the bulk acceleration (i.e., the
spine-sheath structure) as well as an emergence of knotty superluminal
features. The spin characterizes the location of the jet stagnation surface
inside the funnel. We suggest that the limb-brightened feature could be
associated with the nature of the BH-driven jet, if the Doppler beaming is a
dominant factor. Our findings can be examined with (sub-)mm VLBI observations,
giving a clue for the origin of the M87 jet.Comment: 29 pages, 23 figures, accepted for publication in Ap
Clinical significance of CADM1/TSLC1/IgSF4 expression in Adult-T cell leukemia/lymphoma (ATLL): identification of various types of ATLL cells
Parabolic Jets from the Spinning Black Hole in M87
The M87 jet is extensively examined by utilizing general relativistic magnetohydrodynamic (GRMHD) simulations, as well as the steady axisymmetric force-free electrodynamic (FFE) solution. Quasi-steady funnel jets are obtained in GRMHD simulations up to the scale of ~100 gravitational radii (r(sub g)) for various black hole (BH) spins. As is known, the funnel edge is approximately determined by the following equipartitions: (i) the magnetic and rest-mass energy densities and (ii) the gas and magnetic pressures. Our numerical results give an additional factor that they follow the outermost parabolic streamline of the FFE solution, which is anchored to the event horizon on the equatorial plane. We also show that the matter-dominated, nonrelativistic corona/wind plays a dynamical role in shaping the funnel jet into the parabolic geometry. We confirm a quantitative overlap between the outermost parabolic streamline of the FFE jet and the edge of the jet sheath in very long baseline interferometry (VLBI) observations at ~(10(exp 1)10(exp 5))r(sub g), suggesting that the M87 jet is likely powered by the spinning BH. Our GRMHD simulations also indicate a lateral stratification of the bulk acceleration (i.e., the spine-sheath structure), as well as an emergence of knotty superluminal features. The spin characterizes the location of the jet stagnation surface inside the funnel. We suggest that the limb-brightened feature could be associated with the nature of the BH-driven jet, if the Doppler beaming is a dominant factor. Our findings can be examined with (sub)millimeter VLBI observations, giving a clue for the origin of the M87 jet
Coincidence analysis to search for inspiraling compact binaries using TAMA300 and LISM data
Japanese laser interferometric gravitational wave detectors, TAMA300 and
LISM, performed a coincident observation during 2001. We perform a coincidence
analysis to search for inspiraling compact binaries. The length of data used
for the coincidence analysis is 275 hours when both TAMA300 and LISM detectors
are operated simultaneously. TAMA300 and LISM data are analyzed by matched
filtering, and candidates for gravitational wave events are obtained. If there
is a true gravitational wave signal, it should appear in both data of detectors
with consistent waveforms characterized by masses of stars, amplitude of the
signal, the coalescence time and so on. We introduce a set of coincidence
conditions of the parameters, and search for coincident events. This procedure
reduces the number of fake events considerably, by a factor
compared with the number of fake events in single detector analysis. We find
that the number of events after imposing the coincidence conditions is
consistent with the number of accidental coincidences produced purely by noise.
We thus find no evidence of gravitational wave signals. We obtain an upper
limit of 0.046 /hours (CL ) to the Galactic event rate within 1kpc from
the Earth. The method used in this paper can be applied straightforwardly to
the case of coincidence observations with more than two detectors with
arbitrary arm directions.Comment: 28 pages, 17 figures, Replaced with the version to be published in
Physical Review
Results of the search for inspiraling compact star binaries from TAMA300's observation in 2000-2004
We analyze the data of TAMA300 detector to search for gravitational waves
from inspiraling compact star binaries with masses of the component stars in
the range 1-3Msolar. In this analysis, 2705 hours of data, taken during the
years 2000-2004, are used for the event search. We combine the results of
different observation runs, and obtained a single upper limit on the rate of
the coalescence of compact binaries in our Galaxy of 20 per year at a 90%
confidence level. In this upper limit, the effect of various systematic errors
such like the uncertainty of the background estimation and the calibration of
the detector's sensitivity are included.Comment: 8 pages, 4 Postscript figures, uses revtex4.sty The author list was
correcte
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