Resonant Inelastic X-Ray Scattering at the K Edge of Ge

We study the resonant inelastic x-ray scattering (RIXS) at the $K$ edge of Ge. We measure RIXS spectra with systematically varying momenta in the final state. The spectra are a measure of exciting an electron-hole pair. We find a single peak structure (except the elastic peak) as a function of photon energy, which is nearly independent of final-state momenta. We analyze the experimental data by means of the band structure calculation. The calculation reproduces well the experimental shape, clarifying the implication of the spectral shape.Comment: 17 pages,9 figures, Please also see our related paper: cond-mat/040500

Suzaku Reveals Helium-burning Products in the X-ray Emitting Planetary Nebula BD+303639

BD+303639, the brightest planetary nebula at X-ray energies, was observed with Suzaku, an X-ray observatory launched on 2005 July 10. Using the X-ray Imaging Spectrometer, the K-lines from C VI, O VII, and O VIII were resolved for the first time, and C/O, N/O, and Ne/O abundance ratios determined. The C/O and Ne/O abundance ratios exceed the solar value by a factor of at least 30 and 5, respectively. These results indicate that the X-rays are emitted mainly by helium shell-burning products.Comment: 12 pages, 4 figures, accepted for publication in The Astrophysical Journal Letter

Relações entre a intensidade e duração das atividades em partida de basquetebol com as capacidades aeróbica e anaeróbica: estudo pelo lactato sangüíneo

Os esportes com bola se caracterizam pela alternância de períodos de atividades de curta duração e alta intensidade intercalados com períodos de recuperação. Neste tipo de exercício, o metabolismo anaeróbico é considerado predominante, porém, o seu grau de solicitação depende da distribuição dessas atividades ao longo da partida. Com o propósito de caracterizar o perfil da atividade e a relação com o metabolismo predominante em partida, jogadores de uma equipe de basquetebol foram submetidos a teste de campo para avaliação do condicionamento anaeróbico (5 x 30 m em velocidade máxima com 1 minuto de pausa) e aeróbico (limiar de lactato, 4 mM em 3 x 1200 m progressivos). Em três partidas foram determinados o lactato sangüíneo, e através de videotape, a distribuição da duração de atividades de alta e baixa intensidade. Durante as partidas o lactato sangüíneo atingiu valores de 2,68 — 1,30 mM, e foi significativamente correlacionado (p < 0,05) com a duração das atividades de baixa intensidade e longa duração (superior a 3") (63,4 — 3,5 %, r = -0,451), alta intensidade e curta duração (inferior a 3”) (11,2 - 1,4 %, r = 0,477) e alta intensidade e longa duração (10,4 —1,1 %, r = 0,900). Houve correlação significativa também entre o lactato médio em partida com o tempo médio (4,28 — 0,24 s, r = -0,758) e lactato (5,15 - 1,42 mM, r = 0,645) nos tiros de 30 m. Esses resultados indicam que durante a partida de basquetebol há predominância do metabolismo anaeróbico alático e que nos períodos de interrupção do jogo, há possibilidade de remoção do lactato circulanteThe ball games represent intermittent work with frequent interchange of short bursts of physcial effort interspaced with pauses. For this reason they are generally considered anaerobic type activities. However, the extent of anaerobic yield is highly correlated with the effort:relief ratio pattern. The present study was designed in order to investigate the metabolic profile of basketball game, particullary the extent of the anaerobic metabolism, and its relation with the intensity of the activities during a game and the aerobic and anaerobic condition of the player. Basketball players (n =14) were evaluated in a set of field test consisted with: a) anaerobic capacity, 5 x 30 m at maximal running speed, with 1 min rest and b) aerobic capacity expressed as a anaerobic threshold (blood lactate = 4 mM 3 x 1200 m graded field test). Three games were videotaped and the duration of high and low intensity activities were determined. Additionally blood samples were obtained at the end of the game for lactate analysis (YSL 2300, Yellow Spring Co, USA). The blood lactate during the games (2.68 — 1.30 mM) was significantly correlated with the duration of the long term (more than 3 s) low intensity activities (63.4 - 3.5 %, r = - 0.451), the short term (less than 3 s) high intensity activities (11.2 — 1.4 %, r = 0.477) and long term high intensity activities (10.4 — 1.1 %, r = 0.900). Significant correlations were also found between the game blood lactate and the mean running time (4.28 -1 0.24 s, r = - 0.758) and blood lactate (5.15 — 1.42 mM, r = 0.645) in the 30 m dashes. These findings showed that the anaerobic alatacid metabolism is the main energy source for the basketball game. Additionally, the blood lactate are removed during the light activities which interspace the high intensity bursts of effort

X-ray Temperature and Mass Measurements to the Virial Radius of Abell 1413 with Suzaku

We present X-ray observations of the northern outskirts of the relaxed galaxy cluster A1413 with Suzaku, whose XIS instrument has the low intrinsic background needed to make measurements of these low surface brightness regions. We excise 15 point sources superimposed on the image above a flux of $1\times 10^{-14}$ \fluxunit (2--10keV) using XMM-Newton and Suzaku images of the cluster. We quantify all known systematic errors as part of our analysis, and show our statistical errors encompasses them for the most part. Our results extend previous measurements with Chandra and XMM-Newton, and show a significant temperature drop to about 3keV at the virial radius, $r_{200}$. Our entropy profile in the outer region ($> 0.5 r_{200}$) joins smoothly onto that of XMM-Newton, and shows a flatter slope compared with simple models, similar to a few other clusters observed at the virial radius. The integrated mass of the cluster at the virial radius is approximately $7.5\times10^{14}M_{\odot}$ and varies by about 30% depending on the particular method used to measure it.Comment: 32pages, 9 figures, accepted for publication in PAS

A strong excess in the 20-100 keV emission of NGC 1365

We present a new Suzaku observation of the obscured AGN in NGC 1365, revealing an unexpected excess of X-rays above 20 keV of at least a factor ~2 with respect to the extrapolation of the best-fitting 3-10 keV model. Additional Swift-BAT and Integral-IBIS observations show that the 20-100 keV is concentrated within ~1.5 arcmin from the center of the galaxy, and is not significantly variable on time scales from days to years. A comparison of this component with the 3-10 keV emission, which is characterized by a rapidly variable absorption, suggests a complex structure of the circumnuclear medium, consisting of at least two distinct components with rather different physical properties, one of which covering >80% of the source with a column density NH~3-4x10^24 cm^(-2). An alternative explanation is the presence of a double active nucleus in the center of NGC 1365.Comment: 13 pages, 3 figures. Accepted for publication in ApJ Letter

Precision Fe Kalpha and Fe Kbeta Line Spectroscopy of the Seyfert 1.9 Galaxy NGC 2992 with Suzaku

We present detailed time-averaged X-ray spectroscopy in the 0.5--10 keV band of the Seyfert~1.9 galaxy NGC 2992 with the Suzaku X-ray Imaging Spectrometers (XIS). We model the complex continuum in detail. There is an Fe K line emission complex that we model with broad and narrow lines and we show that the intensities of the two components are decoupled at a confidence level >3sigma. The broad Fe K line has an EW of 118 (+32,-61) eV and could originate in an accretion disk (with inclination angle greater than ~30 degrees). The narrow Fe Kalpha line has an EW of 163 (+47,-26) eV and is unresolved FWHM <4090 km/s) and likely originates in distant matter. The absolute flux in the narrow line implies that the column density out of the line-of-sight could be much higher than measured in the line-of-sight, and that the mean (historically-averaged) continuum luminosity responsible for forming the line could be a factor of several higher than that measured from the data. We also detect the narrow Fe Kbeta line with a high signal-to-noise ratio and describe a new robust method to constrain the ionization state of Fe responsible for the Fe Kalpha and Fe Kbeta lines that does not require any knowledge of possible gravitational and Doppler energy shifts affecting the line energies. For the distant line-emitting matter (e.g. the putative obscuring torus) we deduce that the predominant ionization state is lower than Fe VIII (at 99% confidence), conservatively taking into account residual calibration uncertainties in the XIS energy scale and theoretical and experimental uncertainties in the Fe K fluorescent line energies. From the limits on a possible Compton-reflection continuum it is likely that the narrow Fe Kalpha and Fe Kbeta lines originate in a Compton-thin structure.Comment: Abstract is abridged. Accepted for publication in the Suzaku special issue of PASJ (November 2006). 18 pages, 6 figure

XMM-Newton and Suzaku detection of an X-ray emitting shell around the pulsar wind nebula G54.1+0.3

Recent X-ray observations have proved to be very effective in detecting previously unknown supernova remnant shells around pulsar wind nebulae (PWNe), and in these cases the characteristics of the shell provide further clues on the evolutionary stage of the embedded PWN. However, it is not clear why some PWNe are still "naked". We carried out an X-ray observational campaign targeted at the PWN G54.1+0.3, the "close cousin" of the Crab, with the aim to detect the associated SNR shell. We analyzed an XMM-Newton and Suzaku observations of G54.1+0.3 and we model out the contribution of dust scattering halo. We detected an intrinsic faint diffuse X-ray emission surrounding a hard spectrum, which can be modeled either with a power-law (gamma= 2.9) or with a thermal plasma model (kT=2.0 keV.). If the shell is thermal, we derive an explosion energy E=0.5-1.6x10^51 erg, a pre-shock ISM density of 0.2 cm^-3 and an age of about 2000 yr. Using these results in the MHD model of PWN-SNR evolution, we obtain an excellent agreement between the predicted and observed location of the shell and PWN shock.Comment: Accepted for publication in A&A, 8 pages, 5 figures, full-res version at http://www.astropa.inaf.it/Library/OAPA_preprints/h14298.pd

X-Ray Spectral Variability of the Seyfert Galaxy NGC 4051 Observed with Suzaku

We report results from a Suzaku observation of the narrow-line Seyfert 1 NGC 4051. During our observation, large amplitude rapid variability is seen and the averaged 2--10 keV flux is 8.1x10^-12 erg s^-1 cm^-2, which is several times lower than the historical average. The X-ray spectrum hardens when the source flux becomes lower, confirming the trend of spectral variability known for many Seyfert 1 galaxies. The broad-band averaged spectrum and spectra in high and low flux intervals are analyzed. The spectra are first fitted with a model consisting of a power-law component, a reflection continuum originating in cold matter, a blackbody component, two zones of ionized absorber, and several Gaussian emission lines. The amount of reflection is rather large (R ~ 7, where R=1 corresponds to reflection by an infinite slab), while the equivalent width of the Fe-K line at 6.4 keV is modest (140 eV) for the averaged spectrum. We then model the overall spectra by introducing partial covering for the power-law component and reflection continuum independently. The column density for the former is 1x10^23 cm^-2, while it is fixed at 1x10^24 cm-2 for the latter. By comparing the spectra in different flux states, we identify the causes of spectral variability. (abridged)Comment: 19 pages, 18 figures, accepted for publication in PASJ (Suzaku 3rd special issue

Dzyaloshinskii--Moriya interaction: How to measure its sign in weak ferromagnetics?

Three experimental techniques sensitive to the sign of the Dzyaloshinskii--Moriya interaction are discussed: neutron diffraction, Moessbauer gamma-ray diffraction, and resonant x-ray scattering. Classical examples of hematite (alpha-Fe2O3) and MnCO3 crystals are considered in detailComment: 5 pages, 1 figure; to be published in JETP Letter