The origin of HE0107-5240 and the production of O and Na in extremely metal-poor stars

We elaborate the binary scenario for the origin of HE0107-5240, the most metal-poor star yet observed ([Fe/H] = -5.3), using current knowledge of the evolution of extremely metal-poor stars. From the observed C/N value, we estimate the binary separation and period. Nucleosynthesis in a helium convective zone into which hydrogen has been injected allows us to discuss the origin of surface O and Na as well as the abundance distribution of s-process elements. We can explain the observed abundances of 12C, 13C, N, O, and Na and predict future observations to validate the Pop III nature of HE0107-5240.Comment: 4 pages, 3 figures, proceedings of the conference, "Nuclei in the Cosmos VIII", Nuclear Physics A in pres

Interpret Ogoh-ogoh Towards Hindu Contemporary Society

The interpreting of the making ogoh-ogoh based on the perspective of the cultural studies in related to the festival day of the tawur kesanga towards Hindu society in Bali. It recently is an interesting phenomenon to be studied in the academics. Due to the ogoh-ogoh is made as a series for the ceremony of the tawur kesanga lately. It has been a high cost, although, in the literary texts, it does not find the existence of ogoh-ogoh become the completeness of the tawur ceremony itself. Regarding its phenomenon, the author was interested in studying in term of this. The study was intended to interpret the ideology or a truth behind the making of ogoh-ogoh shown of the religious ceremonies. It was conducted applying a qualitative approach included classifying, categorize, understand, and interpret any data or the facts by paraphrase or description, therefore, the conclusion was generally obtained. The results of the analysis were conducted. It can be understood that the making of ogoh-ogoh recently in the Hindu society in Bali, not merely means to cast out of the evil spirits that have been perceived as buta kala by the Hindu society in Bali. However, it was interpreted as a game of the ideology i.e. capitalist ideology. In term of this was evident that the making of ogoh-ogoh lately, no longer using the local materials that can be freely gotten from the surrounding environment, but must be made by lux materials that must be purchased expensive. Thus, it can be concluded that behind the making of ogoh-ogoh related with the ceremony of the tawur kesanga towards Hindu society in Bali lately was initiated by the game of the ideology i.e. capitalist ideology

Explosions inside Ejecta and Most Luminous Supernovae

The extremely luminous supernova SN2006gy is explained in the same way as other SNIIn events: light is produced by a radiative shock propagating in a dense circumstellar envelope formed by a previous weak explosion. The problems in the theory and observations of multiple-explosion SNe IIn are briefly reviewed.Comment: 9 pages, 6 figures, LateX aipproc.cls. A bit more details and color added to Fig.3. The 10th International Symposium on Origin of Matter and Evolution of Galaxies (OMEG07), Sapporo, Japan, December 200

Evolution and nucleosynthesis of extremely metal-poor and metal-free low- and intermediate-mass stars II. s-process nucleosynthesis during the core He flash

Models of primordial and hyper-metal-poor stars with masses similar to the Sun experience an ingestion of protons into the hot core during the core helium flash phase at the end of their red giant branch evolution. This produces a concurrent secondary flash powered by hydrogen burning that gives rise to further nucleosynthesis in the core. We perform post-process nucleosynthesis calculations on a one-dimensional stellar evolution calculation of a star of 1 solar mass and metallicity [Fe/H] = -6.5 that suffers a proton ingestion episode. Our network includes 320 nuclear species and 2,366 reactions and treats mixing and burning simultaneously. The mixing and burning of protons into the hot convective core leads to the production of 13C, which then burns via the 13C(alpha,n)16O reaction releasing a large number of free neutrons. During the first two years of neutron production the neutron poison 14N abundance is low, allowing the prodigious production of heavy elements such as strontium, barium, and lead via slow neutron captures (the s process). These nucleosynthetic products are later mixed to the stellar surface and ejected via stellar winds. We compare our results with observations of the hyper-metal-poor halo star HE 1327-2326, which shows a strong Sr overabundance. Our model provides the possibility of self-consistently explaining the Sr overabundance in HE 1327-2326 together with its C, N, and O overabundances (all within a factor of ~4) if the material were heavily diluted, for example, via mass transfer in a wide binary system. The model produces at least 18 times too much Ba than observed, but this may be within the large modelling uncertainties. In this scenario, binary systems of low mass must have formed in the early Universe. If true then this puts constraints on the primordial initial mass function.Comment: Accepted for publication on Astronomy & Astrophysics Letter

The monitoring system for the aerogel Cherenkov counter of the BELLE detector

We report on a design and performances of a monitoring system developed for the aerogel Cherenkov counters (ACC) of the BELLE detector. The system consists of blue LEDs, a diffuser box, and optical distributors which distribute the LED light to the ACC modules. The employed LED (NSPB series) has been observed to have high reliability on the long term stability and the temprature dependence. The diffuser box is employed to reduce the intrinsic non-uniformity of the LED light intensity. The overall performances of the present monitoring system on uniformity and intensity of the light output have been found to satisfy all the requirements for the monitoring.Comment: 24 pages, LaTeX, 13 eps figures, to be published in Nucl. Instrum. and Meth. A. Postscript file (4.5 MB) is available at http://www-hep.phys.saga-u.ac.jp/~murakami/paper/xxx_accmon.p

Measurement of the 6Li(e,e'p) reaction cross sections at low momentum transfer

The triple differential cross sections for the 6Li(e,e'p) reaction have been measured in the excitation energy region from 27 to 46 MeV in a search for evidence of the giant dipole resonance (GDR) in 6Li. The cross sections have no distinct structures in this energy region, and decrease smoothly with the energy transfer. Angular distributions are different from those expected with the GDR. Protons are emitted strongly in the momentum-transfer direction. The data are well reproduced by a DWIA calculation assuming a direct proton knockout process.Comment: 19 pages, 7 figures, revised text, to be published in Nucl. Phys.

Study of a Threshold Cherenkov Counter Based on Silica Aerogels with Low Refractive Indices

To identify $\pi^{\pm}$ and $K^{\pm}$ in the region of $1.0\sim 2.5$ GeV/c, a threshold Cherenkov counter equipped with silica aerogels has been investigated. Silica aerogels with a low refractive index of 1.013 have been successfully produced using a new technique. By making use of these aerogels as radiators, we have constructed a Cherenkov counter and have checked its properties in a test beam. The obtained results have demonstrated that our aerogel was transparent enough to make up for loss of the Cherenkov photon yield due to a low refractive index. Various configurations for the photon collection system and some types of photomultipliers, such as the fine-mesh type, for a read out were also tested. From these studies, our design of a Cherenkov counter dedicated to $\pi / K$ separation up to a few GeV/c %in the momentum range of $1.0 \sim 2.5$ GeV/c with an efficiency greater than $90$ \% was considered.Comment: 21 pages, latex format (article), figures included, to be published in Nucl. Instrm. Meth.

Recruitment, augmentation and apoptosis of rat osteoclasts in 1,25-(OH)2D3 response to short-term treatment with 1,25-dihydroxyvitamin D3in vivo

Background Although much is known about the regulation of osteoclast (OC) formation and activity, little is known about OC senescence. In particular, the fate of of OC seen after 1,25-(OH)2D3 administration in vivo is unclear. There is evidence that the normal fate of OC is to undergo apoptosis (programmed cell death). We have investigated the effect of short-term application of high dose 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on OC apoptosis in an experimental rat model. Methods OC recruitment, augmentation and apoptosis was visualised and quantitated by staining histochemically for tartrate resistant acid phosphatase (TRAP), double staining for TRAP/ED1 or TRAP/DAPI, in situ DNA fragmentation end labelling and histomorphometric analysis. Results Short-term treatment with high-dose 1,25-(OH)2D3 increased the recruitment of OC precursors in the bone marrow resulting in a short-lived increase in OC numbers. This was rapidly followed by an increase in the number of apoptotic OC and their subsequent removal. The response of OC to 1,25-(OH)2D3 treatment was dose and site dependent; higher doses producing stronger, more rapid responses and the response in the tibiae being consistently stronger and more rapid than in the vertebrae. Conclusions This study demonstrates that (1) after recruitment, OC are removed from the resorption site by apoptosis (2) the combined use of TRAP and ED1 can be used to identify OC and their precursors in vivo (3) double staining for TRAP and DAPI or in situ DNA fragmentation end labelling can be used to identify apoptotic OC in vivo