Novel Non-equilibrium Phase Transition Caused by Non-linear Hadronic-quark Phase Structure

We consider how the occurrence of first-order phase transitions in non-constant pressure differs from those at constant pressure. The former has shown the non-linear phase structure of mixed matter, which implies a particle number dependence of the binding energies of the two species. If the mixed matter is mixed hadron-quark phase, nucleon outgoing from hadronic phase and ingoing to quark phase probably reduces the system to a non-equilibrium state, in other words, there exists the imbalance of the two phases when deconfinement takes place. This novel non-equilibrium process is very analogous to the nuclear reactions that nuclei emit neutrons and absorb them under appropriate conditions. We present self-consistent thermodynamics in description for the processes and identify the microphysics responsible for the processes. The microphysics is an inevitable consequence of non-linear phase structure instead of the effect of an additional dissipation force. When applying our findings to the neutron star containing mixed hadron-quark matter, it is found that the newly discovered energy release might strongly change the thermal evolution behavior of the star.Comment: 18pages,3figures;to be accepted for publication in Physics Letters

The consistency of estimator under fixed design regression model with NQD errors

In this article, basing on NQD samples, we investigate the fixed design nonparametric regression model, where the errors are pairwise NQD random errors, with fixed design points, and an unknown function. Nonparametric weighted estimator will be introduced and its consistency is studied. As special case, the consistency result for weighted kernel estimators of the model is obtained. This extends the earlier work on independent random and dependent random errors to NQD case

An XMM-Newton study of the mixed-morphology supernova remnant W28 (G6.4-0.1)

We have performed an XMM-Newton imaging and spectroscopic study of supernova remnant (SNR) W28, a prototype mixed-morphology or thermal composite SNR, believed to be interacting with a molecular cloud. The observed hot X-ray emitting plasma is characterized by low metal abundances, showing no evidence of ejecta. The X-rays arising from the deformed northeast shell consist of a thermal component with a temperature of $\sim0.3$ keV plus a hard component of either thermal (temperature $\sim 0.6$ keV) or non-thermal (photon index $=0.9$-2.4) origin. The X-ray emission in the SNR interior is blobby and the corresponding spectra are best described as the emission from a cold ($kT\sim0.4$ keV) plasma in non-equilibrium ionization with an ionization timescale of $\sim4.3\times 10^{11}$ cm$^{-3}$ s plus a hot ($kT \sim 0.8$ keV) gas in collisional ionization equilibrium. Applying the two-temperature model to the smaller central regions, we find non-uniform interstellar absorption, temperature and density distribution, which indicates that the remnant is evolving in a non-uniform environment with denser material in the east and north. The cloudlet evaporation mechanism can essentially explain the properties of the X-ray emission in the center and thermal conduction may also play a role for length scales comparable to the remnant radius. A recombining plasma model with an electron temperature of $\sim 0.6$ keV is also feasible for describing the hot central gas with the recombination age of the gas estimated at $\sim2.9\times 10^4$ yr.Comment: 16 pages, 7 figures, 5 tables, ApJ in pres

Diaqua­(5,5,7,12,12,14-hexa­methyl-1,4,8,11-tetra­azacyclo­tetra­deca­ne)nickel(II) tetra­cyanidonickelate(II)

In the title complex, [Ni(C16H36N4)(H2O)2][Ni(CN)4], the [Ni(teta)(H2O)2]2+ cations (teta = 5,5,7,12,12,14-hexa­methyl-1,4,8,11-tetra­azacyclo­tetra­deca­ne) and [Ni(CN)4]2− anions are arranged in an alternating fashion through electrostatic and N—H⋯N and O—H⋯N hydrogen-bonding inter­actions, forming a two-dimensional layered structure. Adjacent layers are linked through weak van der Waals inter­actions, resulting in a three-dimensional supra­molecular network

A Study of Fermi-LAT GeV gamma-ray Emission towards the Magnetar-harboring Supernova Remnant Kesteven 73 and Its Molecular Environment

We report our independent GeV gamma-ray study of the young shell-type supernova remnant (SNR) Kes 73 which harbors a central magnetar, and CO-line millimeter observations toward the SNR. Using 7.6 years of Fermi-LAT observation data, we detected an extended gamma-ray source ("source A") with the centroid on the west of the SNR, with a significance of 21.6 sigma in 0.1-300 GeV and an error circle of 5.4 arcminute in angular radius. The gamma-ray spectrum cannot be reproduced by a pure leptonic emission or a pure emission from the magnetar, and thus a hadronic emission component is needed. The CO-line observations reveal a molecular cloud (MC) at V_LSR~90 km/s, which demonstrates morphological correspondence with the western boundary of the SNR brightened in multiwavelength. The 12CO (J=2-1)/12CO (J=1-0) ratio in the left (blue) wing 85-88 km/s is prominently elevated to ~1.1 along the northwestern boundary, providing kinematic evidence of the SNR-MC interaction. This SNR-MC association yields a kinematic distance 9 kpc to Kes 73. The MC is shown to be capable of accounting for the hadronic gamma-ray emission component. The gamma-ray spectrum can be interpreted with a pure hadronic emission or a magnetar+hadronic hybrid emission. In the case of pure hadronic emission, the spectral index of the protons is 2.4, very similar to that of the radio-emitting electrons, essentially consistent with the diffusive shock acceleration theory. In the case of magnetar+hadronic hybrid emission, a magnetic field decay rate >= 10^36 erg/s is needed to power the magnetar's curvature radiation.Comment: 7 figures, published in Ap

7-Chloro-5-(2-ethoxy­phen­yl)-1-methyl-3-propyl-2,6-dihydro-1H-pyrazolo[4,3-d]pyrimidine

In the title compound, C17H21ClN4O, the benzene ring is oriented at dihedral angles of 1.59 (3) and 1.27 (3)° with respect to the pyrimidine and pyrazole rings, while the dihedral angle between the pyrimidine and pyrazole rings is 0.83 (3)°. An intra­molecular N—H⋯O hydrogen bond results in the formation of a planar (r.m.s. deviation 0.004 Å) six-membered ring