119432492
Evolution of deformations in medium-mass nuclei
Evolution of quadrupole deformations in sd- and pf-shell nuclei with mass A=18-56 is studied by using deformed Skyrme Hartree-Fock model with pairing correlations. We point out that the quadrupole deformations of the nuclei with the isospin T=0 and T=1 show strong mass number dependence as a clear manifestation of dynamical evolution of deformation in nuclear many-body systems. The competition between the deformation driving particle-vibration coupling and the closed-shell structure is shown in a systematic study of the ratios between the proton and neutron deformations in nuclei with T=|T{sub z}|=1. Calculated quadrupole and hexadecapole deformations are compared with shell model results and available experimental data. A relation between the skin thickness and the intrinsic Q{sub 2} moments is also discussed.
121212177
Hypernuclei in the deformed Skyrme-Hartree-Fock approach
The properties of Lambda hypernuclei in a broad mass region are studied by using a deformed Hartree-Fock approach using realistic nucleonic Skyrme forces, pairing correlations, and a microscopically determined lambda-nucleon interaction based on Brueckner-Hartree-Fock calculations of hypernuclear matter. The results suggest that the core nuclei and the corresponding hypernuclei have similar deformations with the same sign. Some light single-Lambda hypernuclei are substantially deformed and the Lambda binding energy is modified by the deformation.
118278930
Tensor correlation, pairing interaction, and deformation in Ne isotopes and Ne hypernuclei
We study tensor and pairing effects on the quadruple deformation of neon isotopes based on a deformed Skyrme-Hartree-Fock model with BCS approximation for the pairing channel. We extend the SkyrmeHartree-Fock formalism for the description of single- and d ouble-lambda hypernuclei adopting two different hyperon-nucleon interactions. It is found that the inte rplay of pairing and tensor interactions is crucial to derive the deformations in several neon isotopes. Especi ally, the shapes of 26,30 Ne are studied in details in comparisons with experimentally observed shapes. Furthermore the deformations of the hypernuclei are compared with the corresponding neon isotopic cores in the presence of tensor force. We find the same shapes with somewhat smaller deformations for single Λ-hypernuclei compared with their core deformations. It is also pointed out that the latest version of hyper on interaction, the ESC08b model, having a deeper Λ potential makes smaller deformations for hypernuclei than those of another NSC97f model.
120362009
Effect of tensor force on the shell structure of superheavy nuclei
Conference Name:11th International Conference on Nucleus-Nucleus Collisions, NN 2012. Conference Address: San Antonio, TX, United states. Time:May 27, 2012 - June 1, 2012.
118531588
Protoneutron stars in the Brueckner-Hartree-Fock approach and finite-temperature kaon condensation
National Natural Science Foundation of China [10605018, 10905048, 10975116]; Chinese Academy of Sciences [KJCX3-SYW-N2]; Program for New Century Excellent Talents in University [NCET-07-0730]; European Commission [CN/ASIA-LINK/008(94791)]; European Scienc
120746694
Effect of tensor interaction on deformation and shell structure of medium-heavy and superheavy nuclei
Japanese Ministry of Education, Culture, Sports, Science and Technology [(C (2)) 20 540 277]; National Science Foundation of China [10 975 116]; Program for New Century Excellent Talents in University [NCET-07-0730]; Fundamental Research Funds for the Central Universities [2010 121 011]
118308331
A COMPARISON OF HARD X-RAY PHOTON INDICES AND IRON Kα EMISSION LINES IN X-RAY LUMINOUS NARROW- AND BROAD-LINE SEYFERT 1 GALAXIES
We use publicly available XMM-Newton data to systematically compare the hard X-ray photon indices, Γ2-10 keV , and the iron Kα emission lines of narrow- and broad-line Seyfert 1 (NLS1 and BLS1) galaxies. We compile a flux-limited (f 2-10 keV ≥ 1 × 10–12 erg s–1 cm–2) sample including 114 radio-quiet objects, with the 2-10 keV luminosity ranging from 1041 to 1045 erg s–1. Our main results are: (1) NLS1s and BLS1s show similar luminosity distributions; (2) the weighted means of Γ2-10 keV of NLS1s, BLS1s, and the total sample are 2.04 ± 0.04, 1.74 ± 0.02, and 1.84 ± 0.02, respectively; a significant anti-correlation between Γ2-10 keV and FWHMHβ suggests that Γ2-10 keV > 2.0 may be taken to indicate the X-ray luminous NLS1 type; (3) the 6.4 keV narrow iron Kα lines from NLS1s are generally weaker than that from BLS1s; this would indicate a smaller covering factor of the dusty tori in NLS1s if the line emission originates from the inner boundary region of the dusty torus in an active galactic nucleus; and (4) all the broadened iron Kα lines with intrinsic width σ>0.5 keV correspond to FWHMHβ ≤4000 km s–1.
119274239
HST and LAMOST discover a dual active galactic nucleus in J0038+4128
We report the discovery of a kiloparsec-scale dual active galactic nucleus (AGN) in J0038+4128. From the Hubble Space Telescope (HST) Wide Field Planetary Camera (WFPC2) images, we find two optical nuclei with a projection separation of 4.7 kpc (3.44 arcsec). The southern component (J0038+4128S) is spectroscopically observed with the HST Goddard High Resolution Spectrograph in the UV range and is found to be a Seyfert 1 galaxy with a broad Ly alpha emission line. The northern component (J0038+4128N) is spectroscopically observed during the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (also named the Guoshoujing Telescope) pilot survey in the optical range. The observed line ratios as well as the consistency of redshift of the nucleus emission lines and the host galaxy's absorption lines indicate that J0038+4128N is a Seyfert 2 galaxy with narrow lines only. These results thus confirm that J0038+4128 is a Seyfert 1-Seyfert 2 AGN pair. The HST WFPC2 F336W/U-band image of J0038+4128 also reveals for the first time for a dual AGN system two pairs of bi-symmetric arms, as are expected from the numerical simulations of such system. Being one of a few confirmed kiloparsec-scale dual AGNs exhibiting a clear morphological structure of the host galaxies, J0038+4128 provides an unique opportunity to study the co-evolution of the host galaxies and their central supermassive black holes undergoing a merging process.
123628224
Competing fusion and quasifission reaction mechanisms in the production of superheavy nuclei
Within the framework of a dinuclear system model, a new master equation is constructed and solved, which includes the relative distance of nuclei as a new dynamical variable in addition to the mass asymmetry variable so that the nucleon transfer, which leads to fusion and the evolution of the relative distance, which leads to quasifission (QF) are treated simultaneously in a consistent way. The QF mass yields and evaporation residual cross sections to produce superheavy nuclei are systematically investigated under this framework. The results fit the experimental data well. It is shown that the Kramers formula gives results of QF, which agree with those by our diffusion treatment, only if the QF barrier is high enough. Otherwise some large discrepancies occur.
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
124058283
Dynamical deformation in heavy ion collisions and formation of superheavy nuclei