Chandra Observations of a Non-Thermal Supernova Remnant Candidate AX J1843.8-0352 and its Surroundings

We present the Chandra results of AX J1843.8-0352, a supernova remnant (SNR) recently identified with ASCA. Chandra spatially resolved two components from this SNR: non-thermal and thermal ones. The morphology of the non-thermal component is clumpy and elliptical, elongated from the north to the south with a mean diameter of about 9 arcmin. The spectrum is fitted with a power-law model of photon index 2.1 and the east rim is associated with the non-thermal radio sources C and F (Helfand et al. 1989). Therefore the non-thermal component is probably synchrotron X-rays by energetic electrons accelerated at the shell of the SNR. The thermal component is the brightest clump located within the non-thermal component and shows a spectrum of a thin plasma of about 0.7 keV temperature. Notable discovery is its peculiar morphology; a head of 50 arcsec x 30 arcsec size near the south-east rim of the SNR and a 30 arcsec-long ``jet'' pointing to the southwest. Although this emission is associated with the west part of the radio source F, the absorption is twice larger than that of the non-thermal X-rays, or the bulk of the SNR emission. Therefore, it is unclear whether this peculiar plasma is a thermal component associated with AX J1843.8-0352, a Galactic source located in the far side of our Galaxy, or an extragalactic source.Comment: 19 pages, 5 figures; to appear in Ap

Energy Geo-politics of Russia and the Global Energy Security

The world energy market is undergoing a period of great turbulence, and major challenges to global energy security are emerging. Under the current global economic crisis, the world energy demand is likely to stagnate for a couple of years ahead. But in the long run, world energy demand is expected to rise again (China as a centerpiece), when the global economy recovers from the recession. Taking into account of various problems and constraints with regard to supply side, including difficulties to access to resources, unfavorable environment for investment, geopolitical uncertainties, etc, one of the most important challenges is whether the global supply of energy will keep expanding smoothly in line with energy demand. In this regard, development in Russia, which holds great resource potential, is crucial. For Japan, Russia has an important presence in the field of energy issues. The primary reason is that Japan is dependent on imported energy from the global energy market, and that Russia can significantly influence the stability of that market. The second reason is that there is huge oil and gas potential in areas such as Sakhalin and East Siberia which are geographically close to Japan, and their development will greatly affect the energy market in Asia including Japan. In addition, it is important to note that we have witnessed various significant developments in Russia which affect global energy market stability. In particular, we are very much interested in such emerging issues as resource nationalism and reinforcement of state involvement in energy sectors, the Russia-Ukraine gas dispute and disruption of gas supply, and geopolitical issues with Europe, Central Asia and China regarding energy. With this recognition, this paper will address emerging challenges for global energy security with a special focus on the energy situation and strategy in Russia.Energy, energy security, global demand, global supply

Cosmic Star Formation Activity at z=2.2 Probed by H-alpha Emission Line Galaxies

We present a pilot narrow-band survey of H-alpha emitters at z=2.2 in the Great Observatories Origins Deep Survey North (GOODS-N) field with MOIRCS instrument on the Subaru telescope. The survey reached a 3 sigma limiting magnitude of 23.6 (NB209) which corresponds to a 3 sigma limiting line flux of 2.5 x 10^-17 erg s^-1 cm^-2 over a 56 arcmnin^2 contiguous area (excluding a shallower area). From this survey, we have identified 11 H-alpha emitters and one AGN at z=2.2 on the basis of narrow-band excesses and photometric redshifts. We obtained spectra for seven new objects among them, including one AGN, and an emission line above 3 sigma is detected from all of them. We have estimated star formation rates (SFR) and stellar masses (M_star) for individual galaxies. The average SFR and M_star is 27.8M_solar yr^-1 and 4.0 x 10^10M_solar, respectivly. Their specific star formation rates are inversely correlated with their stellar masses. Fitting to a Schechter function yields the H-alpha luminosity function with log L = 42.82, log phi = -2.78 and alpha = -1.37. The average star formation rate density in the survey volume is estimated to be 0.31M_solar yr^-1Mpc^-3 according to the Kennicutt relation between H-alpha luminosity and star formation rate. We compare our H-alpha emitters at z=2.2 in GOODS-N with narrow-band line emitters in other field and clusters to see their time evolution and environmental dependence. We find that the star formation activity is reduced rapidly from z=2.5 to z=0.8 in the cluster environment, while it is only moderately changed in the field environment. This result suggests that the timescale of galaxy formation is different among different environments, and the star forming activities in high density regions eventually overtake those in lower density regions as a consequence of "galaxy formation bias" at high redshifts.Comment: Accepted for publication in PASJ Subaru Special Issue, 11 pages, 10 figure

Octopamine regulates social behaviors between genetically unrelated ant queens.

In different tasks involving action perception, performance has been found to be facilitated when the presented stimuli were produced by the participants themselves rather than by another participant. These results suggest that the same mental representations are accessed during both production and perception. However, with regard to spoken word perception, evidence also suggests that listeners’ representations for speech reflect the input from their surrounding linguistic community rather than their own idiosyncratic productions. Furthermore, speech perception is heavily influenced by indexical cues that may lead listeners to frame their interpretations of incoming speech signals with regard to speaker identity. In order to determine whether word recognition evinces similar self-advantages as found in action perception, it was necessary to eliminate indexical cues from the speech signal. We therefore asked participants to identify noise-vocoded versions of Dutch words that were based on either their own recordings or those of a statistically average speaker. The majority of participants were more accurate for the average speaker than for themselves, even after taking into account differences in intelligibility. These results suggest that the speech representations accessed during perception of noise-vocoded speech are more reflective of the input of the speech community, and hence that speech perception is not necessarily based on representations of one’s own speech

Principal Sensitivity Analysis

We present a novel algorithm (Principal Sensitivity Analysis; PSA) to analyze the knowledge of the classifier obtained from supervised machine learning techniques. In particular, we define principal sensitivity map (PSM) as the direction on the input space to which the trained classifier is most sensitive, and use analogously defined k-th PSM to define a basis for the input space. We train neural networks with artificial data and real data, and apply the algorithm to the obtained supervised classifiers. We then visualize the PSMs to demonstrate the PSA's ability to decompose the knowledge acquired by the trained classifiers