Chandra observations of the H2O megamaser galaxy Mrk1210

We present the first Chandra X-ray observations of the H₂O megamaser galaxy Mrk1210 (UGC4203), a Seyfert 2 galaxy at an approximate distance of D ∼ 57.6 Mpc. The Chandra X-ray image, with by far the highest angular resolution (∼1″), displays an unresolved compact core toward the nuclear region of Mrk1210. Comparisons with the previous X-ray observations in the nuclear emission and the spectral shape indicate a fairly stable phase between 2001 (BeppoSAX and XMM-Newton) and 2004 (Chandra) after a dramatic variation since 1995 (ASCA). The best-fit model of Chandra X-ray spectrum consists of two components. The soft scattered component can be best fitted by a moderately absorbed power-law model adding a spectral line at ∼0.9 keV (possibly a Ne-Kα fluorescent line), while the hard nuclear component can be well reproduced by a heavily absorbed power-law model (N _H ∼ 2×10²³ cm⁻²) with an additional line at ∼6.19 keV (close to the Fe-Kα fluorescent line). The derived absorption-corrected X-ray luminosity implies that the dramatic variation of spectral properties is caused by significant changes of the absorbing column density along the line-of-sight, while the intrinsic nuclear X-ray luminosity remains stable. In this case, the absorbers should be anisotropic and its size can be constrained to be less than 0.0013 pc. In addition, we also estimate the mass of central engine, the disk radius and the accretion rate of the accretion disk to be 10^7.12±0.31 M _⊙, ∼1 pc and 0.006, respectively. Supported by the National Natural Science Foundation of China (Grant No. 10633010) and the Natural Science Foundation of Guangdong Province, China (Grant No. 8451009101001047) Recommended by Zhou YouYuan     

Kinematics of the reaction H2O+(H2,H)H3O+

The kinematics of the reaction H₂O⁺(H₂,H)H₃O⁺ were studied in crossed-beam experiments in the low collision-energy range 0.1–2 eV (c.m.). The scattering diagrams, center-of-mass angular distributions, and product relative translational energy distributions obtained show that the reaction proceeds predominantly by the impulsive, stripping mechanism. The translational exoergicity vs. collision energy plot obeys the spectator-stripping prediction.     

Steric effect in O+/H2 and H+/H2O collisions

The positive water and hydronium ions are of interest in a variety of chemical and biological applications. Here we study the steric effect in charge transfer collisions, i.e. the spatial dependence of single electron capture, in collisions mediated by these ions. In particular, the steric effect is demonstrated in the O⁺(²D)/H₂ and H⁺/H₂O charge transfer collisions in the energy range of 100 eV/amu to 10 keV/amu.     

SIMS,EID and flash-filament investigation of O2, H2, (O2 + H2) and H2O interaction with vanadium

Comparative investigations of secondary ion emission, electron induced ion emission and flash filament signals from polycrystalline vanadium surfaces exposed to well-defined O₂, H₂, H₂O and (O₂ + H₂) doses (<500 L) have been carried out. The vanadium target could be heated and bombarded by either electrons (300 eV) or ions (3 keV) under ultra high vacuum conditions (<10^?10 Torr). The investigations were carried out with a computer controlled ultra high vacuum mass spectrometer. The experimental results establish exact reproducible spectra of well defined surface layers. They give detailed insight into the reactions between H₂, O₂ H₂O and vanadium, and some interactions between these species. They further indicate the importance of bulk and surface diffusion as well as the influence of the probing ion and electron bombardment. A clear distinction between bulk oxygen, surface oxides, and adsorbed oxygen for the vanadium-oxygen interaction at room temperature could be established. For the interaction of hydrogen with clean and oxygen covered vanadium surfaces the formation of adsorbed hydrogen, bulk solution of hydrogen, and the formation of OH groups and H₂O could be demonstrated. A detection limit below 10^?5 of one single monolayer for metal bonded hydrogen could be established.     

The new model of fitting the spectral energy distributions of Mrk 421 and Mrk 501

The spectral energy distribution (SED) of TeV blazars has a double-humped shape that is usually interpreted as a Synchrotron Self Compton (SSC) model. The one zone SSC model is used broadly but cannot fit the high energy tail of SED very well. It needs a bulk Lorentz factor which is in conflict with the observation. Furthermore, a one zone SSC model cannot explain the entire spectrum. We propose a new model where the high energy emission is produced by the accelerated protons in the blob with a small size and high magnetic field, and the low energy radiation comes from the electrons in the expanded blob. Because the high and low energy photons are not produced at the same time, the requirement of a large Doppler factor from pair production is relaxed. We present the fitting results of the SEDs for Mrk 501 during April 1997 and Mrk 421 during March 2001.

     

Raman Scattering of H2O/D2O Solutions

The stretching vibrations of water are perfect characteristics of the hydrogen bond. Studying their frequency shift, changes of intensities, broadening of the bands and appearence of submaxima we can receive very important structural information about the groups involved in H-bonding and about the bond itself. The observed Raman spectra, however, are rather complicated because the OH and OD stretching bands are always superpositions of several bands due to intra- and intermolecular coupling, effect of Fermi resonance etc. The     

Constraints on composite Dirac neutrinos from observations of galaxy clusters

Recently, to explain the origin of neutrino masses a model based on confining some hidden fermionic bound states into right-handed chiral neutrinos has been proposed. One of the consequences of condensing the hidden sector fields in this model is the presence of sterile composite Dirac neutrinos of keV mass, which can form viable warm dark matter particles. We have analyzed constraints on this model from the observations of satellite based telescopes to detect the sterile neutrinos in clusters of galaxies.     

A study on detonation-diffraction reflection point distances in H2/O2, C2H2/O2, and C2H4/O2 systems

Recently, Kawasaki and Kasahara (2019) reported that reflection point distance, which is a detonation characteristic length relevant to the diffraction process, is a useful measure; i.e., the critical condition for detonation diffraction can be universally expressed in terms of the diffraction point distance, independent of mixture stability. However, their findings were limited to their experimental conditions only. In this study, we performed high-speed visualization of processes of cylindrical (line-symmetric) detonation diffraction around a 90-degree corner for two series of experiments to obtained reflection point distances, l_r, as a novel characteristic length, and examined critical conditions of reinitiation expressed in terms of the reflection point distance. In the first experimental series, stoichiometric C₂H₂/O₂ mixtures with 50% Ar dilution were employed, and the channel width l_c was varied to 5, 10, 15, and 20 mm to investigate the influences of the boundary condition of the flow field. In the second experimental series, H₂/O₂, C₂H₂/O₂, or C₂H₄/O₂ mixtures with different equivalence ratios were employed to investigate influences of the reaction systems. Our results confirmed that the channel width does not affect the reflection point distance or the critical condition. The critical condition was also independent of fuel species and equivalence ratio, and can be uniquely expressed as l_r / l_c = 4.0 ± 0.6 in terms of the reflection point distance.     

Surface complexes between O2, H2O and lithium

The He(I) photoelectron spectra of lithium and its surfaces as a function of exposure to O₂ or to H₂O are reported in this paper. The spectra provide evidence for the formation of a stable complex between H₂O and lithium rather than for formation of a product such as LiOH. The spectral evidence for the H₂O/Li complex is supported by calculations using several ten atom models of binding sites on unreconstructed lithium surfaces bearing H₂O in various conformations.     

Characteristics of thermoradiative destruction of BaS2O6·2H2O

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 55, No. 4, pp. 613–618, October, 1991.     

DFT理论研究焦磷酸与水的分子间相互作用

在PBEPBE/6-311++G**水平上,对H4P2O7 单体及H4P2O7…H2O氢键复合物的可能构型进行优化,频率验证,找到复合物的稳定结构,并分析其结构参数,在同样的水平下计算了复合物的结合能,同时进行了振动频率分析。结果表明,H4P2O7 单体稳定构型具有C2对称性,对于H4P2O7…H2O复合物,得到三个稳定构型,其中最稳定复合物的结合能为-18.784kcal/mol,水与H4P2O7作用位置在连接两个相邻磷酸基的分子内氢键上,形成含有两个较强氢键的多元环状复合物。     

Raman spectroscopic study of the arsenite mineral vajdakite [(Mo6+O2)2(H2O)2As3+2O5]·H2O

Raman spectra of vajdakite, [(Mo⁶⁺O₂)₂(H₂O)₂As O₅]·H₂O, were studied and interpreted in terms of the structure of the mineral. The Raman spectra were compared with the published infrared spectrum of vajdakite. The presence of dimolybdenyl and diarsenite units and of hydrogen bonded water molecules was inferred from the Raman spectra which supported the known and published crystal structure of vajdakite. Mo O and O H···O bond lengths were calculated from the Raman spectra. Copyright © 2009 John Wiley & Sons, Ltd.     

Polarisation resistance of the O2, Au/O2− and H2-H2O, Au/O2− electrode systems

Gold electrodes with known contact geometries were studied using impedance spectroscopy. From these data it was possible to determine the specific polarisation conductivity per unit length of three-phase boundary (TPB). The values were found to be (3÷22)×10⁻⁴ S·cm⁻¹ dependent on the electrode history in pure oxygen at 977 °C and 2×10⁻⁶ S·cm⁻¹ at 977 °C in “pure” hydrogen (P_O2=10⁻²⁰ atm at 1001 °C). The results are compared with previous data obtained for platinum electrodes.     

C_8H_8O_7H_2O单晶的振动光谱

Ｃ８Ｈ８Ｏ７Ｈ２Ｏ单晶的振动光谱李丽霞（山东大学环境工程系济南２５０１００）ＴｈｅＶｉｂｒａｔｉｏｎａｌＳｐｅｃｔｒｕｍｏｆＣ８Ｈ８Ｏ７Ｈ２ＯＣｒｙｓｔａｌＬｉＬｉＸｉａ（ＥｎｖｉｒｏｎｍｅｎｔａｌＥｎｇｉｎｅｒｉｎｇＤｅｐａｒｔｍｅｎｔ，Ｓｈａｎｄ...     

Angular distribution of the photoelectron spectrum of CO2, COS,CS2, N2O,H2O,and H2S

The photoelectron spectra of the triatomic molecules CO₂, COS, CS₂, N₂O, H₂O, and H₂S have been measured as a function of the angle θ between the direction of the incoming photon and outgoing photoelectron. The photoelectron spectra have been measured with a double-focusing electrostatic electron spectrometer to which has been attached a chamber containing a gas discharge lamp that can be freely rotated. (The photon source used was the 21.22 eV He I resonance line). From the dependence of intensity as a function of θ the angular parameter β was determined for each ionization band observed in the photoelectron spectra. A correlation was noted between the values of β and the molecular orbitals relative to the contributions of oxygen and sulfur atomic orbitals. Individual β values were also obtained for most of the vibrational bands seen in the photoelectron spectra. In most cases the vibrational structure showed little or no change in the angular parameter for a given electronic state. In certain cases, however, such as the fourth ionization band in CS₂, CO₂, and COS, rather sizeable changes in β were observed for the different vibrational bands.     

ESR of Gamma Irradiated C2H204.2H2O Single Crystal

The gamma-irradiated samples of vacuumed powder and single crystal of C₂H₂O₄.2H₂O have been investigated by ESR method. the spectra of these single crystal and unvacuumed powder are attributed to R C HOH radical, but the peaks belonging to this radical in the gamma irradiated powder sample are not observed in the spectrum after having been vacuumed. After a and g tensor values of this radical have been calculated, it was observed to be anisotropic. At low temperature, a considerable change in the spectrum has not been observed.