5,003 research outputs found
Luminosity Dependent Evolution of Lyman Break Galaxies from redshift 5 to 3
In this contribution we briefly describe our recent results on the properties
of Lyman break galaxies at z~5 obtained from deep and wide blank field surveys
using Subaru telescope, and through the comparison with samples at lower
redshift ranges we discuss the evolution of star-forming galaxies in the early
universe.Comment: 2 pages, 1 figure, for the proceedings of the IAU Symposium 235,
Galaxies Across the Hubble Time, J. Palous & F. Combes, ed
Lyman Break Galaxies at : Rest-Frame UV Spectra
We report initial results for spectroscopic observations of candidates of
Lyman Break Galaxies (LBGs) at in a region centered on the Hubble Deep
Field-North by using the Faint Object Camera and Spectrograph attached to the
Subaru Telescope. Eight objects with mag, including one AGN, are
confirmed to be at . The rest-frame UV spectra of seven LBGs
commonly show no or weak Lyalpha emission line (rest-frame equivalent width of
0-10\AA) and relatively strong low-ionization interstellar metal absorption
lines of SiII 1260, OI+SiII 1303, and CII 1334 (mean
rest-frame equivalent widths of them are \AA). These
properties are significantly different from those of the mean rest-frame UV
spectrum of LBGs at , but are quite similar to those of subgroups of
LBGs at with no or weak Lyalpha emission. The weakness of Lyalpha
emission and strong low-ionization interstellar metal absorption lines may
indicate that these LBGs at are chemically evolved to some degree and
have a dusty environment. Since the fraction of such LBGs at in our
sample is larger than that at , we may witness some sign of evolution
of LBGs from to , though the present sample size is very
small. It is also possible, however, that the brighter LBGs tend to show no or
weak Lyalpha emission, because our spectroscopic sample is bright (brighter
than ) among LBGs at . More observations are required to
establish spectroscopic nature of LBGs at .Comment: 16 pages, 3 figures, accepted by Ap
Ingredients of nuclear matrix element for two-neutrino double-beta decay of 48Ca
Large-scale shell model calculations including two major shells are carried
out, and the ingredients of nuclear matrix element for two-neutrino double beta
decay are investigated. Based on the comparison between the shell model
calculations accounting only for one major shell (-shell) and those for two
major shells (-shell), the effect due to the excitation across the two
major shells is quantitatively evaluated.Comment: To appear in J. Phys. Soc. Conf. Proc. (ARIS2014); for ver.2, Fig.1
is revise
Ferroan relict minerals in the Tottuki and South Pole micrometeorites.
第2回極域科学シンポジウム/第34回南極隕石シンポジウム 11月17日(木) 国立国語研究所 2階講
Determination of Trace Metals in Biological Samples by PIXE Analysis After Solvent Extraction and Polystyrene-Film Collection
開始ページ、終了ページ: 冊子体のページ付
Singular perturbation near mode-coupling transition
We study the simplest mode-coupling equation which describes the time
correlation function of the spherical p-spin glass model. We formulate a
systematic perturbation theory near the mode-coupling transition point by
introducing multiple time scales. In this formulation, the invariance with
respect to the dilatation of time in a late stage yields an arbitrary constant
in a leading order expression of the solution. The value of this constant is
determined by a solvability condition associated with a linear singular
equation for perturbative corrections in the late stage. The solution thus
constructed provides exactly the alpha-relaxation time.Comment: 15 pages, 4 figure
Pickoff and spin-conversion quenchings of ortho-positronium in oxygen
The quenching processes of the thermalized ortho-positronium(o-Ps) on an
oxygen molecule have been studied by the positron annihilation age-momentum
correlation techinique(AMOC). The Doppler broadening spectrum of the 511 keV
gamma-rays from the 2gamma annihilation of o-Ps in O_2 has been measured as a
function of the o-Ps age. The rate of the quenching, consisting of the pickoff
and the spin-conversion, is estimated from the positron lifetime spectrum. The
ratio of the pickoff quenching rate to the spin-conversion rate is deduced from
the Doppler broadening of the 511 keV gamma-rays from the annihilation of the
o-Ps. The pickoff parameter ^1Z_eff, the effective number of the electrons per
molecule which contribute to the pickoff quenching, for O_2 is determined to be
0.6 +- 0.4. The cross-section for the elastic spin-conversion quenching is
determined to be (1.16 +- 0.01) * 10^{-19} cm^2.Comment: 4 pages with 5 eps figures, LaTeX2e(revtex4
- …