714 research outputs found
Pionic Atom Spectroscopy in the (d,3He) reaction at finite angles
We study the formation of deeply bound pionic atoms in the (d,3He) reactions
theoretically and show the energy spectra of the emitted 3He at finite angles,
which are expected to be observed experimentally. We find that the different
combinations of the pion-bound and neutron-hole states dominate the spectra at
different scattering angles because of the matching condition of the reaction.
We conclude that the observation of the (d,3He) reaction at finite angles will
provide the systematic information of the pionic bound states in each nucleus
and will help to develop the study of the pion properties and the partial
restoration of chiral symmetry in nuclei.Comment: 7 pages, 4 figures, 1 tabl
The 2006 Radio Outburst of a Microquasar Cyg X-3: Observation and Data
We present the results of the multi-frequency observations of radio outburst
of the microquasar Cyg X-3 in February and March 2006 with the Nobeyama 45-m
telescope, the Nobeyama Millimeter Array, and the Yamaguchi 32-m telescope.
Since the prediction of a flare by RATAN-600, the source has been monitored
from Jan 27 (UT) with these radio telescopes. At the eighteenth day after the
quench of the activity, successive flares exceeding 1 Jy were observed
successfully. The time scale of the variability in the active phase is
presumably shorter in higher frequency bands.
We also present the result of a follow-up VLBI observation at 8.4 GHz with
the Japanese VLBI Network (JVN) 2.6 days after the first rise. The VLBI image
exhibits a single core with a size of <8 mas (80 AU). The observed image was
almost stable, although the core showed rapid variation in flux density. No jet
structure was seen at a sensitivity of K.Comment: 17 pages,6 figures; accepted by PAS
Variations in the gonadal artery with a single common trunk: embryological hypotheses by observation
Background: A gonadal artery originates as a branch of the abdominal aorta and renal artery inferior to the level of origin of the renal arteries. Variations in multiple right testicular arteries (RTAs) arising from the abdominal aorta are common. We aimed to re-evaluate the unusual courses of gonadal arteries with a single common trunk in relation to the inferior vena cava and left renal vein and explain the developmental anatomy. Materials and methods: The observational cross-sectional study was performed on 54 Japanese adult cadavers (29 men and 25 women). We examined the literature and developed embryological hypotheses on the single common trunk of the gonadal artery. Results: The gonadal artery, testicular artery, and ovarian artery arose from the abdominal aorta in 93.1%, 96.3%, and 89.6% of cases, respectively, and from the renal artery in 4.9%, 3.7%, and 6.3% of cases, respectively. We found two rare variations in the RTAs observed during the routine dissection of two male cadavers; in these two cases, a single common trunk of the RTAs originated from the abdominal aorta. A single common trunk was found in 3.7% of cadavers, 2.0% of sides, and 2.0% of arteries in the gonadal artery and in 6.9% of cadavers, 3.8% of sides, and 3.7% of arteries in the testicular artery. All cases of the single common trunk, including those in past reports, were observed only in men. Conclusions: Knowledge of the variations in RTAs has important clinical consequences for invasive and non-invasive arterial procedures. In addition, this variation provides a new interpretation of the embryology of the gonadal artery. Variations similar to our findings have not been previously reported. Therefore, different variations concerning the RTA should be considered during surgical and non-surgical evaluations
The ortho-to-para ratio of ammonia in the L1157 outflow
We have measured the ortho-to-para ratio of ammonia in the blueshifted gas of
the L1157 outflow by observing the six metastable inversion lines from (J, K) =
(1, 1) to (6, 6). The highly excited (5, 5) and (6, 6) lines were first
detected in the low-mass star forming regions. The rotational temperature
derived from the ratio of four transition lines from (3, 3) to (6, 6) is
130-140 K, suggesting that the blueshifted gas is heated by a factor of ~10 as
compared to the quiescent gas. The ortho-to-para ratio of the NH3 molecules in
the blueshifted gas is estimated to be 1.3--1.7, which is higher than the
statistical equilibrium value. This ratio provides us with evidence that the
NH3 molecules have been evaporated from dust grains with the formation
temperature between 18 and 25 K. It is most likely that the NH3 molecules on
dust grains have been released into the gas phase through the passage of strong
shock waves produced by the outflow. Such a scenario is supported by the fact
that the ammonia abundance in the blueshifted gas is enhanced by a factor of ~5
with respect to the dense quiescent gas.Comment: 16 pages, including 3 PS figures. To appear in the ApJ (Letters).
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