118669017
HARD X-RAY PHOTON INDEX AS AN INDICATOR OF BOLOMETRIC CORRECTION IN ACTIVE GALACTIC NUCLEI
We propose the rest-frame 2-10 keV photon index, {Gamma}{sub 2-10keV}, acting as an indicator of the bolometric correction, L {sub bol}/L {sub 2-10keV} (where L {sub bol} is the bolometric luminosity and L {sub 2-10keV} is the rest-frame 2-10 keV luminosity), in radio-quiet active galactic nuclei (AGNs). Correlations between {Gamma}{sub 2-10keV} and both bolometric correction and Eddington ratio are presented, based on simultaneous X-ray, UV, and optical observations of reverberation-mapped AGNs. These correlations can be compared with those for high-redshift AGNs to check for any evolutionary effect. Assuming no evolutionary effect in AGNs' spectral properties, together with the independent estimates of L {sub 2-10keV}, the bolometric correction, Eddington ratio, and black hole (BH) mass can all be estimated from these correlations for high-redshift AGNs, with the mean uncertainty of a factor of 2-3. If there are independent estimates of BH masses, {Gamma}{sub 2-10keV} for high-redshift AGNs can be used to determine their true L {sub bol} and L {sub 2-10keV}, and in conjunction with the redshift can be potentially used to place constraints on cosmology by comparison with the rest-frame 2-10 keV flux. We find that the true L {sub 2-10keV} estimated from {Gamma}{sub 2-10keV} for the brightest Type Imore » AGNs with z < 1 in the Lockman Hole is generally in agreement with the observed L {sub 2-10keV}. However, there are still many uncertainties, such as the accurate determination of the intrinsic {Gamma}{sub 2-10keV} for distant AGNs and the large uncertainty in the luminosities obtained, which call for significant further study before 'AGN cosmology' can be considered a viable technique.« less
51813822
Ionization structure and Fe K$\alpha$ energy for irradiated accretion disks
We study the radial ionization structure at the surface of an X-ray illuminated accretion disk. We plot the expected iron K$\alpha$ line energy as a function of the Eddington ratio and of the distance of the emitting matter from the central source, for a non-rotating and a maximally-rotating black hole. We compare the predicted disk line energies with those measured in an archival sample of active galactic nuclei observed with {\it Chandra}, {\it XMM-Newton} and {\it Suzaku}, and discuss whether the line energies are consistent with the radial distances inferred from reverberation studies. We also suggest using rapidly-variable iron K$\alpha$ lines to estimate the viscosity parameter of an accretion disk. There is a forbidden region in the line energy versus Eddington ratio plane, at low Eddington ratios, where an accretion disk cannot produce highly-ionized iron K$\alpha$ lines. If such emission is observed in low-Eddington-ratio sources, it is either coming from a highly-ionized outflow, or is a blue-shifted component from fast-moving neutral matter.
120020411
PROPERTIES OF NUCLEI AND HYPERNUCLEI WITH THE DEFORMED SKYRME HARTREE-FOCK MODEL
The isotope dependence of the deformation in carbon and neon isotopes is studied in deformed Skyrme Hartree–Fock model. We find that the deformations of C and Ne isotopes have a strong isotope dependence as a manisfestation of spontaneous breaking effect in nuclear physics. By extending the deformed Skyrme Hartree–Fock model, we studied the properties of Λ hypernuclei in a broad mass region. The results suggest that the core nuclei and the corresponding hypernuclei have similar deformations with the same sign. Some light single-Λ hypernuclei are substantially deformed and the Λ binding energy is modified by the deformation.
123014665
EFFECT OF TENSOR INTERACTION ON HEAVY AND SUPERHEAVY NUCLEI
The effect of tensor interaction is discussed on the deformation and the shell structure of heavy and superheavy nuclei within the deformed Skyrme Hartree-Fock+BCS model. The importance of the tensor correlations is shown for the single particle spectra of protons in 249Bk. The large shell gaps of superheavy nuclei are found at Z = 114 and Z = 120 for protons and N = 184 for neutrons with the spherical shape irrespective of the tensor correlations. It is also shown that Z = 114 and N = 164 shell gaps are more pronounced by the tensor correlations in the case of SLy5+T interaction.
120706325
Nonrelativistic mean-field description of the deformation of Λ hypernuclei
The deformations of light Λ hypernuclei are studied in an extended nonrelativistic deformed Skyrme-Hartree-Fock approach with realistic modern nucleonic Skyrme forces, pairing correlations, and a microscopical lambda-nucleon interaction derived from Brueckner-Hartree-Fock calculations. Compared to the large effect of an additional Λ particle on nuclear deformation in the light soft nuclei within relativistic mean field method, this effect is much smaller in the nonrelativistic mean-field approximation.
14590623
Nuclear structure of Hf-178 related to the spin-16, 31-year isomer
The projected shell model is used to study the multi-quasiparticle and collective excitations of Hf-178. With an axially symmetric basis, the spin-16 isomer at 2.4 MeV appears to be well separated in energy/spin space from other configurations. However, projected energy surface calculations suggest that Hf-178 has significant softness to axially asymmetric shapes, which can strongly modify the level distribution. The implications for photodeexcitation of the isomer are discussed. (C) 2004 Elsevier B.V. All rights reserved.
123928525
Kaonic nuclei in the Skyrme-Hartree-Fock approach
National Natural Science Foundation of China [10975116, 11275160]; Fundamental Research Funds for the Central Universities [2010121011]