ASTRO-H White Papers are meant to provide useful information to scientists who plan observations from the satellite. This short paper introduces the 16 ASTRO-H White Papers in addition to general description of the satellite and its new features.
We evaluate the strangeness-conserving $N N$, $SigmaSigma$, $XiXi$, $LambdaSigma$ and the strangeness-changing $Lambda N$, $Sigma N$, $LambdaXi$, $SigmaXi$ axial charges in lattice QCD with two flavors of dynamical quarks and extend our previous work
on pseudoscalar-meson-octet-baryon coupling constants so as to include $piXiXi$, $KLambdaXi$ and $KSigmaXi$ coupling constants. We find that the axial charges have rather weak quark-mass dependence and the breaking in SU(3)-flavor symmetry is small at each quark-mass point we consider.
We report on the results from Suzaku broadband X-ray observations of the galactic binary source LS5039. The Suzaku data, which have continuous coverage of more than one orbital period, show strong modulation of the X-ray emission at the orbital perio
d of this TeV gamma-ray emitting system.The X-ray emission shows a minimum at orbital phase ~ 0.1, close to the so-called superior conjunction of the compact object, and a maximum at phase ~0.7, very close to the inferior conjunction of the compact object. The X-ray spectral data up to 70 keV are described by a hard power-law with a phase-dependent photon index which varies within Gamma ~1.45 - 1.61. The amplitude of the flux variation is a factor of 2.5, but is significantly less than that of the factor ~8 variation in the TeV flux. Otherwise the two light curves are similar, but not identical. Although periodic X-ray emission has been found from many galactic binary systems, the Suzaku result implies a phenomenon different from the standard origin of X-rays related to the emission of the hot accretion plasma formed around the compact companion object. The X-ray radiation of LS5039is likely to be linked to very-high-energy electrons which are also responsible for the TeV gamma-ray emission. While the gamma-rays are the result of inverse Compton scattering by electrons on optical stellar photons, X-rays are produced via synchrotron radiation. Yet, while the modulation of the TeV gamma-ray signal can be naturally explained by the photon-photon pair production and anisotropic inverse Compton scattering, the observed modulation of synchrotron X-rays requires an additional process, the most natural one being adiabatic expansion in the radiation production region.
We evaluate the $pi N!N$, $piSigmaSigma$, $piLambdaSigma$, $KLambda N$ and $K Sigma N $ coupling constants and the corresponding monopole masses in lattice QCD with two flavors of dynamical quarks. The parameters representing the SU(3)-flavor symmetr
y are computed at the point where the three quark flavors are degenerate at the physical $s$-quark mass. In particular, we obtain $alphaequiv F/(F+D)=0.395(6)$. The quark-mass dependences of the coupling constants are obtained by changing the $u$- and the $d$-quark masses. We find that the SU(3)-flavor parameters have weak quark-mass dependence and thus the SU(3)-flavor symmetry is broken by only a few percent at each quark-mass point we consider.
We perform the first study for the bound states of colored scalar particles $phi$ (scalar quarks) in terms of mass generation with quenched SU(3)$_c$ lattice QCD. We investigate the bound states of $phi$, $phi^daggerphi$ and $phiphiphi$ (scalar-quark
hadrons), as well as the bound states of $phi$ and quarks $psi$, i.e., $phi^daggerpsi$, $psipsiphi$ and $phiphipsi$ (chimera hadrons). All these new-type hadrons including $phi$ have a large mass of several GeV due to large quantum corrections by gluons, even for zero bare scalar-quark mass $m_phi=0$ at $a^{-1}sim 1{rm GeV}$. We find a similar $m_psi$-dependence between $phi^daggerpsi$ and $phiphipsi$, which indicates their similar structure due to the large mass of $phi$. From this study, we conjecture that all colored particles generally acquire a large effective mass due to dressed gluons.
The NeXT (New exploration X-ray Telescope), the new Japanese X-ray Astronomy Satellite following Suzaku, is an international X-ray mission which is currently planed for launch in 2013. NeXT is a combination of wide band X-ray spectroscopy (3 - 80 keV
) provided by multi-layer coating, focusing hard X-ray mirrors and hard X-ray imaging detectors, and high energy-resolution soft X-ray spectroscopy (0.3 - 10 keV) provided by thin-foil X-ray optics and a micro-calorimeter array. The mission will also carry an X-ray CCD camera as a focal plane detector for a soft X-ray telescope and a non-focusing soft gamma-ray detector. With these instruments, NeXT covers very wide energy range from 0.3 keV to 600 keV. The micro-calorimeter system will be developed by international collaboration lead by ISAS/JAXA and NASA. The simultaneous broad bandpass, coupled with high spectral resolution of Delta E ~ 7 eV by the micro-calorimeter will enable a wide variety of important science themes to be pursued.
A Suzaku observation of the nucleus of the radio-loud AGN Centaurus A in 2005 has yielded a broadband spectrum spanning 0.3 to 250 keV. The net exposure times after screening were: 70 ks per X-ray Imaging Spectrometer (XIS) camera, 60.8 ks for the Ha
rd X-ray Detector (HXD) PIN, and 17.1 ks for the HXD-GSO. The hard X-rays are fit by two power-laws of the same slope, absorbed by columns of 1.5 and 7 * 10^{23} cm^{-2} respectively. The spectrum is consistent with previous suggestions that the power-law components are X-ray emission from the sub-pc VLBI jet and from Bondi accretion at the core, but it is also consistent with a partial covering interpretation. The soft band is dominated by thermal emission from the diffuse plasma and is fit well by a two-temperature VAPEC model, plus a third power-law component to account for scattered nuclear emission, jet emission, and emission from X-ray Binaries and other point sources. Narrow fluorescent emission lines from Fe, Si, S, Ar, Ca and Ni are detected. The Fe K alpha line width yields a 200 light-day lower limit on the distance from the black hole to the line-emitting gas. Fe, Ca, and S K-shell absorption edges are detected. Elemental abundances are constrained via absorption edge depths and strengths of the fluorescent and diffuse plasma emission lines. The high metallicity ([Fe/H]=+0.1) of the circumnuclear material suggests that it could not have originated in the relatively metal-poor outer halo unless enrichment by local star formation has occurred. Relative abundances are consistent with enrichment from Type II and Ia supernovae.
