A Short Review of Relativistic Iron Lines from Stellar-Mass Black Holes
Miller, J M
2006-01-01
In this contribution, I briefly review recent progress in detecting and measuring the properties of relativistic iron lines observed in stellar-mass black hole systems, and the aspects of these lines that are most relevant to studies of similar lines in Seyfert-1 AGN. In particular, the lines observed in stellar-mass black holes are not complicated by complex low-energy absorption or partial-covering of the central engine, and strong lines are largely independent of the model used to fit the underlying broad-band continuum flux. Indeed, relativistic iron lines are the most robust diagnostic of black hole spin that is presently available to observers, with specific advantages over the systematics-plagued disk continuum. If accretion onto stellar-mass black holes simply scales with mass, then the widespread nature of lines in stellar-mass black holes may indicate that lines should be common in Seyfert-1 AGN, though perhaps harder to detect.
Fabian, A C; Parker, M L
2014-01-01
Broad emission lines, particularly broad iron-K lines, are now commonly seen in the X-ray spectra of luminous AGN and Galactic black hole binaries. Sensitive NuSTAR spectra over the energy range of 3-78 keV and high frequency reverberation spectra now confirm that these are relativistic disc lines produced by coronal irradiation of the innermost accretion flow around rapidly spinning black holes. General relativistic effects are essential in explaining the observations. Recent results are briefly reviewed here.
Evidence for a relativistic iron line in GRS 1915+105
Martocchia, A; Karas, V; Belloni, T; Feroci, M
2002-01-01
We report on the discovery of a relativistic iron K\\alpha fluorescent emission line in the BeppoSAX spectrum of the microquasar GRS 1915+105, taken on April 19, 1998, when the line was unusually intense. The feature is broad and skewed, clearly indicating emission from the innermost regions of the accretion disc. The inner emitting orbit is larger than the innermost stable orbit, even in Schwarzschild metric: thus, a non-zero BH spin is not required by these data.
Looking into the inner black hole accretion disc with relativistic models of iron line
Svoboda, Jiri
2010-01-01
We discuss black hole spin measurements employing the relativistic iron line profiles in the X-ray domain. We investigate the iron line band for two representative sources -- MCG -6-30-15 (active galaxy) and GX 339-4 (X-ray binary). We compare two models of the broad iron line, LAOR and KYRLINE. We realise that the spin is currently determined entirely from the position of the marginally stable orbit while the effect of the spin on the overall line shape would be resolvable with higher resolution X-ray missions. We show that the precision of the spin measurements depends on an unknown angular distribution of the disc emission. We study how sensitive the spin determination is to the assumptions about the intrinsic angular distribution of the emitted photons. We find that the uncertainty of the directional emission distribution translates to 20% uncertainty in the determination of the radius of marginally stable orbit. We perform radiation transfer computations of an X-ray irradiated disc atmosphere (NOAR code)...
Reynolds, C S
1997-01-01
The broad iron K$\\alpha$ emission line, commonly seen in the X-ray spectrum of Seyfert nuclei, is thought to originate when the inner accretion disk is illuminated by an active disk-corona. We show that relative motion between the disk and the X-ray emitting material can have an important influence on the observed equivalent width (EW) of this line via special relativistic aberration and Doppler effects. We suggest this may be relevant to understanding why the observed EW often exceeds the prediction of the standard X-ray reflection model. Several observational tests are suggested that could disentangle these special relativistic effects from iron abundance effects.
Relativistic Iron Line Emission from the Neutron Star Low-mass X-ray Binary 4U 1636-536
Pandel, Dirk; Kaaret, Philip; Corbel, Stephane
2008-01-01
We present an analysis of XMM-Newton and RXTE data from three observations of the neutron star LMXB 4U 1636-536. The X-ray spectra show clear evidence of a broad, asymmetric iron emission line extending over the energy range 4-9 keV. The line profile is consistent with relativistically broadened Fe K-alpha emission from the inner accretion disk. The Fe K-alpha line in 4U 1636-536 is considerably broader than the asymmetric iron lines recently found in other neutron star LMXBs, which indicates...
Relativistic iron K X-ray Reverberation in NGC 4151
Zoghbi, A; Reynolds, C S; Cackett, E M
2011-01-01
Recent X-ray observations have enabled the study of reverberation delays in AGN for the first time. All the detections so far are in sources with a strong soft excess, and the measured delay is between the hard (1-3 keV) direct continuum and the soft excess (0.5-1 keV), interpreted as the reflection continuum smeared by relativistic effects. There is however an inherent ambiguity in identifying and studying the details of the lines in the soft excess. Here we report the first detection of reverberation in the iron K band in any AGN. Using XMM-Newton observations of NGC 4151, we find delays of order 2000 s on time-scales of 10e5 s between the 5-6 keV band and 2-3 and 7-8 keV bands, with a broad lag profile resembling a relativistically-broadened iron line. The peak of the lag spectra shifts to lower energies at higher frequencies, consistent with the red wing of the line being emitted at smaller radii, as expected from reflection off the inner accretion disk. This is a first detection of a broad iron line usin...
Miller, J M; Fabian, A C; Homan, J; Nowak, M A; Wijnands, R; Van der Klis, M; Belloni, T; Tomsick, J A; Smith, D M; Charles, P A; Lewin, W H G
2004-01-01
We observed the Galactic black hole GX 339-4 with the Chandra High Energy Transmission Grating Spectrometer (HETGS) for 75 ksec during the decline of its 2002-2003 outburst. The sensitivity of this observation provides an unprecedented glimpse of a Galactic black hole at about a tenth of the luminosity of the outburst peak. The continuum spectrum is well described by a model consisting of multicolor disk blackbody (kT = 0.6 keV) and power-law (Gamma = 2.5) components. X-ray reflection models yield improved fits. A strong, relativistic Fe K-alpha emission line is revealed, indicating that the inner disk extends to the innermost stable circular orbit. The line is not sufficiently broad to strongly require black hole spin. Absorption lines from H-like and He-like O, and He-like Ne and Mg are detected, as well as lines which are likely due to Ne II and Ne III. The measured line properties make it difficult to associate the absorption with the coronal phase of the interstellar medium. A scenario wherein the absorp...
Iron Line Variability of Discoseismic Corrugation Modes
Tsang, David
2013-01-01
Using a fast semi-analytic raytracing code, we study the variability of relativistically broadened iron lines due to discoseismic oscillations concentrated in the inner-most regions of accretion discs around black holes. The corrugation mode, or c-mode, is of particular interest as its natural frequency corresponds well to the ~0.1-15Hz range observed for low-frequency quasi-periodic oscillations (LFQPOs) for lower spins. Comparison of the oscillation phase dependent variability and QPO-phase stacked iron line observations will allow such discoseismic models to be confirmed or ruled out as a source of particular LFQPOs. The spectral range and frequency of the variability of the iron line due to corrugation modes can also potentially be used to constrain the black hole spin if observed with sufficient temporal and spectral resolution.
Müller, A; Mueller, Andreas; Camenzind, Max
2004-01-01
Relativistic emission lines generated by thin accretion disks around rotating black holes are an important diagnostic tool for testing gravity near the horizon. The iron K-line is of special importance for the interpretation of the X-ray emission of Seyfert galaxies, quasars and galactic X-ray binary systems. A generalized kinematic model is presented which includes radial drifts and non-Keplerian rotations for the line emitters. The resulting line profiles are obtained with an object-oriented ray tracer operating in the curved Kerr background metric. The general form of the Doppler factor is presented which includes all kinds of poloidal and toroidal motions near the horizon. The parameters of the model include the spin parameter, the inclination, the truncation and outer radius of the disk, velocity profiles for rotation and radial drift, the emissivity profile and a multi-species line-system. The red wing flux is generally reduced when radial drift is included as compared to the pure Keplerian velocity fie...
Line Emission from Optically Thick RelativisticAccretion Tori
Fuerst, Steven V.; /KIPAC, Menlo Park /Mullard Space Sci. Lab.; Wu, Kinwah; /Mullard Space Sci. Lab.
2007-09-14
We calculate line emission from relativistic accretion tori around Kerr black holes and investigate how the line profiles depend on the viewing inclination, spin of the central black hole, parameters describing the shape of the tori, and spatial distribution of line emissivity on the torus surface. We also compare the lines with those from thin accretion disks. Our calculations show that lines from tori and lines from thin disks share several common features. In particular, at low and moderate viewing inclination angles they both have asymmetric double-peaked profiles with a tall, sharp blue peak and a shorter red peak which has an extensive red wing. At high viewing inclination angles they both have very broad, asymmetric lines which can be roughly considered as single-peaked. Torus and disk lines may show very different red and blue line wings, but the differences are due to the models for relativistic tori and disks having differing inner boundary radii. Self-eclipse and lensing play some role in shaping the torus lines, but they are effective only at high inclination angles. If inner and outer radii of an accretion torus are the same as those of an accretion disk, their line profiles show substantial differences only when inclination angles are close to 90{sup o}, and those differences are manifested mostly at the central regions of the lines instead of the wings.
Broad Iron Lines in AGN and X-ray Binaries
Fabian, A C
2004-01-01
Several AGN and black hole X-ray binaries show a clear very broad iron line which is strong evidence that the black holes are rapidly spinning. Detailed analysis of these objects shows that the emission line is not significantly affected by absorption and that the source variability is principally due to variation in amplitude of a power-law. Underlying this is a much less variable, relativistically-smeared, reflection-dominated, component which carries the imprint of strong gravity at a few gravitational radii. The strong gravitational light bending in these regions then explains the power-law variability as due to changes in height of the primary X-ray source above the disc. The reflection component, in particular its variability and the profile of the iron line, enables us to study the innermost regions around an accreting, spinning, black hole.
49 CFR 192.373 - Service lines: Cast iron and ductile iron.
2010-10-01
... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron... cast iron pipe or ductile iron pipe is installed for use as a service line, the part of the...
Correlation function and electronic spectral line broadening in relativistic plasmas
Douis S.
2013-01-01
Full Text Available The electrons dynamics and the time autocorrelation function Cee(t for the total electric microfield of the electrons on positive charge impurity embedded in a plasma are considered when the relativistic dynamic of the electrons is taken into account. We have, at first, built the effective potential governing the electrons dynamics. This potential obeys a nonlinear integral equation that we have solved numerically. Regarding the electron broadening of the line in plasma, we have found that when the plasma parameters change, the amplitude of the collision operator changes in the same way as the time integral of Cee(t. The electron-impurity interaction is taken at first time as screened Deutsh interaction and at the second time as Kelbg interaction. Comparisons of all interesting quantities are made with respect to the previous interactions as well as between classical and relativistic dynamics of electrons.
49 CFR 192.487 - Remedial measures: Distribution lines other than cast iron or ductile iron lines.
2010-10-01
... cast iron or ductile iron lines. 192.487 Section 192.487 Transportation Other Regulations Relating to... iron or ductile iron lines. (a) General corrosion. Except for cast iron or ductile iron pipe, each... the purpose of this paragraph. (b) Localized corrosion pitting. Except for cast iron or ductile...
Neronov, A
2015-01-01
We show that observation of the time-dependent effect of microlensing of relativistically broadened emission lines (such as e.g. the Fe Kalpha line in X-rays) in strongly lensed quasars could provide data on celestial mechanics of circular orbits in the direct vicinity of the horizon of supermassive black holes. This information can be extracted from the observation of evolution of red / blue edge of the magnified line just before and just after the period of crossing of the innermost stable circular orbit by the microlensing caustic. The functional form of this evolution is insensitive to numerous astrophysical parameters of the accreting black hole and of the microlensing caustics network system (as opposed to the evolution the full line spectrum). Measurement of the temporal evolution of the red / blue edge could provide a precision measurement of the radial dependence of the gravitational redshift and of velocity of the circular orbits, down to the innermost stable circular orbit. These measurements could...
XMM-Newton and Broad Iron Lines
Fabian, A C
2007-01-01
Iron line emission is common in the X-ray spectra of accreting black holes. When the line emission is broad or variable then it is likely to originate from close to the black hole. X-ray irradiation of the accretion flow by the power-law X-ray continuum produces the X-ray 'reflection' spectrum which includes the iron line. The shape and variability of the iron lines and reflection can be used as a diagnostic of the radius, velocity and nature of the flow. The inner radius of the dense flow corresponds to the innermost stable circular orbit and thus can be used to determine the spin of the black hole. Studies of broad iron lines and reflection spectra offer much promise for understanding how the inner parts of accretion flows (and outflows) around black holes operate. There remains great potential for XMM-Newton to continue to make significant progress in this work. The need for high quality spectra and thus for long exposure times is paramount.
Relativistic X-ray Lines from the Inner Accretion Disks Around Black Holes
Miller, J M
2007-01-01
Relativistic X-ray emission lines from the inner accretion disk around black holes are reviewed. Recent observations with the Chandra X-ray Observatory, X-ray Multi-Mirror Mission-Newton, and Suzaku are revealing these lines to be good probes of strong gravitational effects. A number of important observational and theoretical developments are highlighted, including evidence of black hole spin and effects such as gravitational light bending, the detection of relativistic lines in stellar-mass black holes, and evidence of orbital-timescale line flux variability. In addition, the robustness of the relativistic disk lines against absorption, scattering, and continuum effects is discussed. Finally, prospects for improved measures of black hole spin and understanding the spin history of supermassive black holes in the context of black hole-galaxy co-evolution are presented. The best data and most rigorous results strongly suggest that relativistic X-ray disk lines can drive future explorations of General Relativiti...
Iron Line Profiles in Strong Gravity
Beckwith, K; Beckwith, Kris; Done, Chris
2004-01-01
We describe a new code which can accurately calculate the relativistic effects which distort the emission from an accretion disc around a black hole. We compare our results for a disk from 6-20r_g in both Schwarzchild and extreme Kerr spacetimes with the two line profile codes which are on general release in the XSPEC spectral fitting package. These are generally accurate at the 10-20% level for this range of radii, but have some drawbacks in terms of assumptions and/or resolution. In particular we show that the assumed form of the angular emissivity law (limb darkening or brightening) can make significant changes to the derived line profile. Lightbending effects are never negligible at these radii, so the observed line is produced from a range of different emitted angles, and this can affect the derived radial emissivity law. The line profile is not simply determined by the well defined (but numerically difficult) physical effects of strong gravity, but is also dependent on the poorly known astrophysics of t...
Relativistic Iron K Emission and absorption in the Seyfert 1.9 galaxy MCG-5-23-16
Braito, V; Dewangan, G C; George, I; Griffiths, R E; Markowitz, A; Nandra, K; Porquet, D; Ptak, A; Turner, T J; Yaqoob, T; Weaver, K
2007-01-01
We present the results of the simultaneous deep XMM and Chandra observations of the bright Seyfert 1.9 galaxy MCG-5-23-16, which is thought to have one of the best known examples of a relativistically broadened iron K-alpha line. The time averaged spectral analysis shows that the iron K-shell complex is best modeled with an unresolved narrow emission component (FWHM < 5000 km/s, EW ~ 60 eV) plus a broad component. This latter component has FWHM ~ 44000 km/s and EW ~ 50 eV. Its profile is well described by an emission line originating from an accretion disk viewed with an inclination angle ~ 40^\\circ and with the emission arising from within a few tens of gravitational radii of the central black hole. The time-resolved spectral analysis of the XMM EPIC-pn spectrum shows that both the narrow and broad components of the Fe K emission line appear to be constant in time within the errors. We detected a narrow sporadic absorption line at 7.7 keV which appears to be variable on a time-scale of 20 ksec. If associa...
Discovery of Red-Skewed K_alpha iron line in Cyg X-2 with Suzaku
Shaposhnikov, Nikolai; Laurent, Philippe
2009-01-01
We report on the Suzaku observation of neutron star low-mass X-ray binary Cygnus X-2 which reveals a presence of the iron K_alpha emission line. The line profile shows a significant red wing. This discovery increases the number of neutron star sources where red-skewed iron lines were observed and strongly suggests that this phenomenon is common not only in black holes but also in other types of accreting compact objects. We examine the line profile in terms of models which attribute its production to the relativistic effects due to reflection of X-ray radiation from a cold accretion disk and also as a result of the line formation in the extended wind/outflow configuration. Both models are able to adequately represent the observed line profile. We consider the results of line modeling in the context of subsecond variability. While we were unable to conclusively disqualify one of the models, we find that the wind paradigm has several advantages over the relativistic disk reflection model.
Iron and zinc availability in maize lines
Valéria Aparecida Vieira Queiroz
2011-09-01
Full Text Available The aim of this study was to characterize the Zn and Fe availability by phytic acid/Zn and phytic acid/Fe molar ratios, in 22 tropical maize inbred lines with different genetic backgrounds. The Zn and Fe levels were determined by atomic absorption spectrophotometry and the P through colorimetry method. Three screening methods for phytic acid (Phy analysis were tested and one, based on the 2,2'-bipyridine reaction, was select. There was significant variability in the contents of zinc (17.5 to 42 mg.kg-1, iron (12.2 to 36.7 mg.kg-1, phosphorus (230 to 400 mg.100 g-1, phytic acid (484 to 1056 mg.100 g-1, phytic acid P (140 to 293 mg.100 g-1 and available-P (43.5 to 199.5 mg.100 g-1, and in the available-P/total-P ratio (0.14 to 0.50, Phy/Zn (18.0 to 43.5 and Phy/Fe (16.3 to 45.5 molar ratios. Lines 560977, 560978 and 560982 had greater availability of Zn and lines 560975, 560977, 561010 and 5610111 showed better Fe availability. Lines 560975, 560977 and 560978 also showed better available-P/total-P ratio. Thus, the lines 560975, 560977 and 560978 were considered to have the potential for the development of cultivars of maize with high availability of Fe and/or Zn.
Relativistic Fe Kα line study in Seyfert 1 galaxies observed with Suzaku
Mantovani, G.; Nandra, K.; Ponti, G.
2016-06-01
We present an analysis of a sample of Seyfert 1 galaxies observed with Suzaku. The aim of this work is to examine critically the evidence for a relativistic Fe Kα line in the X-ray spectra of these active galactic nuclei. The sample was compiled from those sources in which a relativistic component was missing in at least one XMM-Newton observation. We analysed the Suzaku spectra of these objects in order to have more constraints on the high-energy emission, including the Compton reflection hump. The results show that the relativistic Fe Kα line is detected (at >95 per cent confidence) in all sources observed with high-signal-to-noise ratio (e.g. where the counts in the 5-7 keV energy band are ≳4 × 104). This is in agreement with the idea that relativistic lines are a ubiquitous feature in the spectra of Seyfert galaxies, but are often difficult to detect without very high-quality data. We also investigate the relation between the Fe Kα line and the reflection continuum at high energies. For most of the sample, the strength of the reflection component is consistent with that of the line. There are exceptions in both senses, however i.e. where the reflection continuum is strong but with weak line emission, and vice versa. These observations present a challenge for standard reflection models.
Constraints on Black Hole Spin in a Sample of Broad Iron Line AGN
Brenneman, Laura W.; Reynolds, Christopher S.
2008-01-01
We present a uniform X-ray spectral analysis of nine type-1 active galactic nuclei (AGN) that have been previously found to harbor relativistically broadened iron emission lines. We show that the need for relativistic effects in the spectrum is robust even when one includes continuum "reflection" from the accretion disk. We then proceed to model these relativistic effects in order to constrain the spin of the supermassive black holes in these AGN. Our principal assumption, supported by recent simulations of geometrically-thin accretion disks, is that no iron line emission (or any associated Xray reflection features) can originate from the disk within the innermost stable circular orbit. Under this assumption, which tends to lead to constraints in the form of lower limits on the spin parameter, we obtain non-trivial spin constraints on five AGN. The spin parameters of these sources range from moderate (a approximates 0.6) to high (a > 0.96). Our results allow, for the first time, an observational constraint on the spin distribution function of local supermassive black holes. Parameterizing this as a power-law in dimensionless spin parameter (f(a) varies as absolute value of (a) exp zeta), we present the probability distribution for zeta implied by our results. Our results suggest 90% and 95% confidence limits of zeta > -0.09 and zeta > -0.3 respectively.
49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.
2010-10-01
... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Connections to cast iron or ductile...) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.369 Service lines: Connections to cast iron...
Relativistic Fe K alpha line study in Seyfert 1 galaxies observed with Suzaku
Mantovani, Giulia; Ponti, Gabriele
2016-01-01
We present an analysis of a sample of Seyfert 1 galaxies observed with Suzaku. The aim of this work is to examine critically the evidence for a relativistic Fe K alpha line in the X-ray spectra of these AGN. The sample was compiled from those sources in which a relativistic component was missing in at least one XMM-Newton observation. We analysed the Suzaku spectra of these objects in order to have more constraints on the high energy emission, including the Compton reflection hump. The results show that the relativistic Fe K alpha line is detected (at >95% confidence) in all sources observed with high signal-to-noise ratio (e.g. where the counts in the 5-7 keV energy band are > 4 x 10^4). This is in agreement with the idea that relativistic lines are a ubiquitous feature in the spectra of Seyfert galaxies, but are often difficult to detect without very high quality data. We also investigate the relation between the Fe K alpha line and the reflection continuum at high energies. For most of the sample, the stre...
A study for testing the Kerr metric with AGN iron line eclipses
Cardenas-Avendano, Alejandro; Bambi, Cosimo
2016-01-01
Recently, two of us have studied iron line reverberation mapping to test black hole candidates, showing that the time information in reverberation mapping can better constrain the Kerr metric than the time-integrated approach. Motivated by this finding, here we explore the constraining power of another time-dependent measurement: an AGN iron line eclipse. An obscuring cloud passes between the AGN and the distant observer, covering different parts of the accretion disk at different times. Similar to the reverberation measurement, an eclipse might help to better identify the relativistic effects affecting the X-ray photons. However, this is not what we find. We explain our results pointing out an important difference between reverberation and eclipse measurements.
Svoboda, J; Goosmann, R W; Karas, V
2009-01-01
Spin of an accreting black hole can be determined by spectroscopy of the emission and absorption features produced in the inner regions of an accretion disc. We discuss the method employing the relativistic line profiles of iron in the X-ray domain, where the emergent spectrum is blurred by general relativistic effects. Precision of spectra fitting procedure could be compromised by inappropriate account of the angular distribution of the disc emission. Often a unique profile is assumed, invariable over the entire range of radii in the disc and energy in the spectral band. We study how sensitive the spin determination is to the assumptions about the intrinsic angular distribution of the emitted photons. We find that the uncertainty of the directional emission distribution translates to 20% uncertainty in determination of the marginally stable orbit. By assuming a rotating black hole in the centre of an accretion disc, we perform radiation transfer computations of an X-ray irradiated disc atmosphere to determin...
Unveiling the broad band X-ray continuum and iron line complex in Mkr 841
Petrucci, P O; Matt, G; Longinotti, A L; Malzac, J; Mouchet, M; Boisson, C; Maraschi, L; Nandra, K; Ferrando, P
2007-01-01
Mkr 841 is a bright Seyfert 1 galaxy known to harbor a strong soft excess and a variable K$\\alpha$ iron line. It has been observed during 3 different periods by XMM for a total cumulated exposure time of $\\sim$108 ks. We present in this paper a broad band spectral analysis of the complete EPIC-pn data sets. We were able to test two different models for the soft excess, a relativistically blurred photoionized reflection (\\r model) and a relativistically smeared ionized absorption (\\a model). The continuum is modeled by a simple cut-off power law and we also add a neutral reflection. These observations reveal the extreme and puzzling spectral and temporal behaviors of the soft excess and iron line. The 0.5-3 keV soft X-ray flux decreases by a factor 3 between 2001 and 2005 and the line shape appears to be a mixture of broad and narrow components. We succeed in describing this complex broad-band 0.5-10 keV spectral variability using either \\r or \\a to fit the soft excess. Both models give statistically equivalen...
Broad K$\\alpha$ iron line from accretion disks around traversable wormholes
Bambi, Cosimo
2013-01-01
It has been proposed that the supermassive black hole candidates at the centers of galaxies might be wormholes formed in the early Universe and connecting our Universe with other sister Universes. The analysis of the profile of the relativistic K$\\alpha$ iron line is currently the only available approach to probe the spacetime geometry around these objects. In this paper, I compute the expected K$\\alpha$ iron line in some wormhole spacetimes and I compare the results with the line produced around Kerr black holes. The line produced in accretion disks around non-rotating or very slow-rotating wormholes is relatively similar to the one expected around Kerr black holes with mid or high value of spin parameter and current observations are still marginally compatible with the possibility that the supermassive black hole candidates in galactic nuclei are these objects. For wormholes with spin parameter $a_* \\gtrsim 0.02$, the associated K$\\alpha$ iron line is instead quite different from the one produced around Ker...
Proton rich nuclei at and beyond the proton drip line in the Relativistic Mean Field theory
Geng, L S; Meng, J
2003-01-01
The Relativistic Mean Field theory is applied to the analysis of ground-state properties of deformed proton-rich odd-Z nuclei in the region $55\\le Z \\le 73$ >. The model uses the TMA and NL3 effective interactions in the mean-field Lagrangian, and describes pairing correlations by the density-independent delta-function interaction. The model predicts the location of the proton drip line, the ground-state quadrupole deformation, one-proton separation energy at and beyond the proton drip line, the deformed single-particle orbital occupied by the odd valence proton and the corresponding spectroscopic factor. The results are in good agreement with the available experimental data except for some odd-odd nuclei in which the proton-neutron pairing may become important and are close to those of Relativistic Hartree-Bogoliubov model.
Transmission Line Analogy for Relativistic Poynting-Flux Jets
Lovelace, R V E
2012-01-01
Radio emission, polarization, and Faraday rotation maps of the radio jet of the galaxy 3C 303 have shown that one knot of this jet carries a {\\it galactic}-scale electric current and that it is magnetically dominated. We develop the theory of magnetically dominated or Poynting-flux jets by making an analogy of a Poynting jet with a transmission line or waveguide carrying a net current and having a potential drop across it (from the jet's axis to its radius) and a definite impedance which we derive. Time-dependent but not necessarily small perturbations of a Poynting-flux jet are described by the "telegrapher's equations." These predict the propagation speed of disturbances and the effective wave impedance for forward and backward propagating wave components. A localized disturbance of a Poynting jet gives rise to localized dissipation in the jet which may explain the enhanced synchrotron radiation in the knots of the 3C 303 jet, and also in the apparently stationary knot HST-1 in the jet near the nucleus of t...
Relativistic jets in narrow-line Seyfert 1 galaxies. New discoveries and open questions
D’Ammando F.
2013-12-01
Full Text Available Before the launch of the Fermi satellite only two classes of AGNs were known to produce relativistic jets and thus emit up to the γ-ray energy range: blazars and radio galaxies, both hosted in giant elliptical galaxies. The first four years of observations by the Large Area Telescope on board Fermi confirmed that these two are the most numerous classes of identified sources in the extragalactic γ-ray sky, but the discovery of γ-ray emission from 5 radio-loud narrow-line Seyfert 1 galaxies revealed the presence of a possible emerging third class of AGNs with relativistic jets. Considering that narrow-line Seyfert 1 galaxies seem to be typically hosted in spiral galaxy, this finding poses intriguing questions about the nature of these objects, the onset of production of relativistic jets, and the cosmological evolution of radio-loud AGN. Here, we discuss the radio-to-γ-rays properties of the γ-ray emitting narrow-line Seyfert 1 galaxies, also in comparison with the blazar scenario.
Relativistic jets in narrow-line Seyfert 1 galaxies. New discoveries and open questions
D'Ammando, F; Finke, J; Larsson, J; Giroletti, M
2013-01-01
Before the launch of the Fermi satellite only two classes of AGNs were known to produce relativistic jets and thus emit up to the gamma-ray energy range: blazars and radio galaxies, both hosted in giant elliptical galaxies. The first four years of observations by the Large Area Telescope on board Fermi confirmed that these two are the most numerous classes of identified sources in the extragalactic gamma-ray sky, but the discovery of gamma-ray emission from 5 radio-loud narrow-line Seyfert 1 galaxies revealed the presence of a possible emerging third class of AGNs with relativistic jets. Considering that narrow-line Seyfert 1 galaxies seem to be typically hosted in spiral galaxy, this finding poses intriguing questions about the nature of these objects, the onset of production of relativistic jets, and the cosmological evolution of radio-loud AGN. Here, we discuss the radio-to-gamma-rays properties of the gamma-ray emitting narrow-line Seyfert 1 galaxies, also in comparison with the blazar scenario.
Mondal, Aditya S; Pahari, Mayukh; Misra, Ranjeev; Kembhavi, Ajit K; Raychaudhuri, Biplab
2016-01-01
Broad relativistic iron lines from neutron star X-ray binaries are important probes of the inner accretion disk. The X-ray reflection features can be weakened due to strong magnetic fields or very low iron abundances such as is possible in X-ray binaries with low mass, first generation stars as companions. Here we investigate the reality of the broad iron line detected earlier from the neutron star low mass X-ray binary 4U~1820--30 with a degenerate helium dwarf companion. We perform a comprehensive, systematic broadband spectral study of the atoll source using \\suzaku{} and simultaneous \
Testing the Kerr Nature of Black Hole Candidates using Iron Line Spectra in the CPR Framework
Jiang, Jiachen; Steiner, James F
2015-01-01
The iron K$\\alpha$ line commonly observed in the X-ray spectrum of both stellar-mass and supermassive black hole candidates originates from X-ray fluorescence of the inner accretion disk. Accordingly, it can be used to map the spacetime geometry around these objects. In this paper, we extend previous work using the iron K$\\alpha$ line to test the Kerr black hole hypothesis. We adopt the Cardoso-Pani-Rico parametrization and we test the possibility of constraining possible deviations from the Kerr solution that can be obtained from observations across the range of black hole spins and inclination angles. We confirm previous claims that the iron K$\\alpha$ line is potentially a quite powerful probe for testing the Kerr metric given sufficiently high quality data and with systematics under control, especially in the case of fast-rotating black holes and high inclination angles since both conditions serve to maximize relativistic effects. We find that some geometric perturbations from Kerr geometry manifest more s...
Ways to constrain neutron star equation of state models using relativistic disc lines
Bhattacharyya, Sudip
2011-01-01
Relativistic spectral lines from the accretion disc of a neutron star low-mass X-ray binary can be modelled to infer the disc inner edge radius. A small value of this radius tentatively implies that the disc terminates either at the neutron star hard surface, or at the innermost stable circular orbit (ISCO). Therefore an inferred disc inner edge radius either provides the stellar radius, or can directly constrain stellar equation of state (EoS) models using the theoretically computed ISCO radius for the spacetime of a rapidly spinning neutron star. However, this procedure requires numerical computation of stellar and ISCO radii for various EoS models and neutron star configurations using an appropriate rapidly spinning stellar spacetime. We have fully general relativistically calculated about 16000 stable neutron star structures to explore and establish the above mentioned procedure, and to show that the Kerr spacetime is inadequate for this purpose. Our work systematically studies the methods to constrain Eo...
A quasi-periodic modulation of the iron line centroid energy in the black hole binary H1743-322
Ingram, Adam; van der Klis, Michiel; Middleton, Matthew; Done, Chris; Altamirano, Diego; Heil, Lucy; Uttley, Phil; Axelsson, Magnus
2016-09-01
Accreting stellar-mass black holes often show a `Type-C' quasi-periodic oscillation (QPO) in their X-ray flux and an iron emission line in their X-ray spectrum. The iron line is generated through continuum photons reflecting off the accretion disc, and its shape is distorted by relativistic motion of the orbiting plasma and the gravitational pull of the black hole. The physical origin of the QPO has long been debated, but is often attributed to Lense-Thirring precession, a General Relativistic effect causing the inner flow to precess as the spinning black hole twists up the surrounding space-time. This predicts a characteristic rocking of the iron line between red- and blueshift as the receding and approaching sides of the disc are respectively illuminated. Here we report on XMM-Newton and NuSTAR observations of the black hole binary H1743-322 in which the line energy varies systematically over the ˜4 s QPO cycle (3.70σ significance), as predicted. This provides strong evidence that the QPO is produced by Lense-Thirring precession, constituting the first detection of this effect in the strong gravitation regime. There are however elements of our results harder to explain, with one section of data behaving differently than all the others. Our result enables the future application of tomographic techniques to map the inner regions of black hole accretion discs.
A quasi-periodic modulation of the iron line centroid energy in the black hole binary H 1743-322
Ingram, Adam; Middleton, Matthew; Done, Chris; Altamirano, Diego; Heil, Lucy; Uttley, Phil; Axelsson, Magnus
2016-01-01
Accreting stellar-mass black holes often show a `Type-C' quasi-periodic oscillation (QPO) in their X-ray flux, and an iron emission line in their X-ray spectrum. The iron line is generated through continuum photons reflecting off the accretion disk, and its shape is distorted by relativistic motion of the orbiting plasma and the gravitational pull of the black hole. The physical origin of the QPO has long been debated, but is often attributed to Lense-Thirring precession, a General Relativistic effect causing the inner flow to precess as the spinning black hole twists up the surrounding space-time. This predicts a characteristic rocking of the iron line between red and blue shift as the receding and approaching sides of the disk are respectively illuminated. Here we report on XMM-Newton and NuSTAR observations of the black hole binary H 1743-322 in which the line energy varies systematically over the ~4 s QPO cycle (3.70 sigma significance), as predicted. This provides strong evidence that the QPO is produced...
Broad iron line in the fast spinning neutron-star system 4U 1636-53
Sanna, Andrea; Mendez, Mariano; Altamirano, Diego; Belloni, Tomaso; Linares, Manuel
2013-01-01
We analysed the X-ray spectra of six observations, simultaneously taken with XMM-Newton and Rossi X-ray Timing Explorer (RXTE), of the neutron star low-mass X-ray binary 4U 1636-53. The observations cover several states of the source, and therefore a large range of inferred mass accretion rate. These six observations show a broad emission line in the spectrum at around 6.5 keV, likely due to iron. We fitted this line with a set of phenomenological models of a relativistically broadened line, plus a model that accounts for relativistically smeared and ionised reflection from the accretion disc. The latter model includes the incident emission from both the neutron-star surface or boundary layer and the corona that is responsible for the high-energy emission in these systems. From the fits with the reflection model we found that in four out of the six observations the main contribution to the reflected spectrum comes from the neutron-star surface or boundary layer, whereas in the other two observations the main ...
A Panchromatic View of Relativistic Jets in Narrow-Line Seyfert 1 Galaxies
D'Ammando, F; Finke, J; Larsson, J; Giroletti, M; Raiteri, C M
2016-01-01
The discovery by the Large Area Telescope on board Fermi of variable gamma-ray emission from radio-loud narrow-line Seyfert 1 (NLSy1) galaxies revealed the presence of a possible third class of Active Galactic Nuclei (AGN) with relativistic jets in addition to blazars and radio galaxies. Considering that NLSy1 are usually hosted in spiral galaxies, this finding poses intriguing questions about the nature of these objects and the formation of relativistic jets. We report on a systematic investigation of the gamma-ray properties of a sample of radio-loud NLSy1, including the detection of new objects, using 7 years of Fermi-LAT data with the new Pass 8 event-level analysis. In addition we discuss the radio-to-very-high-energy properties of the gamma-ray emitting NLSy1, their host galaxy, and black hole mass in the context of the blazar scenario and the unification of relativistic jets at different scales.
A Panchromatic View of Relativistic Jets in Narrow-Line Seyfert 1 Galaxies
Filippo D’Ammando
2016-08-01
Full Text Available The discovery by the Large Area Telescope on board Fermi of variable γ-ray emission from radio-loud narrow-line Seyfert 1 (NLSy1 galaxies revealed the presence of a possible third class of Active Galactic Nuclei (AGN with relativistic jets in addition to blazars and radio galaxies. Considering that NLSy1 are usually hosted in spiral galaxies, this finding poses intriguing questions about the nature of these objects and the formation of relativistic jets. We report on a systematic investigation of the γ-ray properties of a sample of radio-loud NLSy1, including the detection of new objects, using 7 years of Fermi-LAT data with the new Pass 8 event-level analysis. In addition we discuss the radio-to-very-high-energy properties of the γ-ray emitting NLSy1, their host galaxy, and black hole mass in the context of the blazar scenario and the unification of relativistic jets at different scales.
Spectral line shifts of alkali atoms in liquid helium: a relativistic density functional approach
Anton, J [Universitaet Kassel, Institut fuer Physik, 34109 Kassel (Germany); Mukherjee, P K [Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700 032 (India); Fricke, B [Universitaet Kassel, Institut fuer Physik, 34109 Kassel (Germany); Fritzsche, S [Universitaet Kassel, Institut fuer Physik, 34109 Kassel (Germany)
2007-06-28
Excitation line shifts of the principal resonance transitions in alkali atoms sodium and cesium embedded inside the liquid helium environment have been calculated using four-component relativistic density functional theory. The effect of the liquid helium environment is assumed to be represented by a cluster of 14 atoms surrounding the central alkali atom. The estimated blue shift of the principal resonance line {sup 2}S {yields}{sup 2}P is 22.8 nm for Na and 16.7 nm for Cs. The result for Cs is in good agreement with the experimental shift of 18.2 nm. In the absence of the experimental data for Na, our result is compared with those of other theoretical estimates.
Nahar, S N; Chen, G X; Pradhan, A K; Nahar, Sultana N.; Eissner, Werner; Chen, Guo-Xin; Pradhan, Anil K.
2003-01-01
An extensive set of fine structure levels and corresponding transition probabilities for allowed and forbidden transitions in Fe XVII is presented. A total of 490 bound energy levels of Fe XVII of total angular momenta 0 <= J <= 7 of even and odd parities with 2 <= n <= 10, 0 <= l <= 8, 0 <= L <= 8, and singlet and triplet multiplicities, are obtained. They translate to over 2.6 x 10^4 allowed (E1) transitions that are of dipole and intercombination type, and about 3000 forbidden transitions that include electric quadrupole (E2), magnetic dipole (M1), electric octopole (E3), and magnetic quadrupole (M2) type representing the most detailed calculations to date for the ion. Oscillator strengths f, line strengths S, and coefficients A of spontaneous emission for the E1 type transitions are obtained in the relativistic Breit-Pauli R-matrix approximation. A valus for the forbidden transitions are obtained from atomic structure calculations using codes SUPERSTRUCTURE and GRASP. The energy le...
An XMM-Newton survey of broad iron lines in AGN
Nandra, K; George, I M; Reeves, J N; Turner, T J
2006-01-01
We report on the iron K-alpha line properties of a sample of Seyfert galaxies observed with the XMM-Newton EPIC pn instrument. Using a systematic and uniform analysis, we find that complexity at iron-K is extremely common in the XMM spectra. Once appropriate soft X-ray absorption, narrow 6.4 keV emission and associated Compton reflection are accounted for, ~75 of the sample show an improvement when a further Gaussian component is introduced. The typical properties of the broad emission are both qualitatively and quantitatively consistent with previous results from ASCA. The complexity is in general very well described by relativistic accretion disk models. In most cases the characteristic emission radius is constrained to be within ~50 R_g, where strong gravitational effects become important. We find in about 1/3 of the sample the accretion disk interpretation is strongly favoured over competing models. In a few objects no broad line is apparent. We find evidence for emission within 6 R_g in only two cases, b...
Fluorescent iron lines as a probe of astrophysical black hole systems
Reynolds, C S; Reynolds, Christopher S.; Nowak, Michael A.
2003-01-01
(abridged) With most physicists and astrophysicists in agreement that black holes do indeed exist, the focus of astrophysical black hole research has shifted to the detailed properties of these systems. Nature has provided us with an extremely useful probe of the region very close to an accreting black hole - X-ray irradiation of relatively cold material in the vicinity of the black hole can imprint characteristic features into the X-ray spectra of black hole systems, most notably the Kalpha fluorescent line of iron. Detailed X-ray spectroscopy of these features can be used to study Doppler and gravitational redshifts, thereby providing key information on the location and kinematics of the cold material. This is a powerful tool that allows us to probe within a few gravitational radii, or less, of the event horizon. Here, we present a comprehensive review of relativistic iron line studies for both accreting stellar mass black holes (i.e., Galactic Black Hole Candidate systems; GBHCs), and accreting supermassiv...
Description of Drip-Line Nuclei within Relativistic Mean-Field Plus BCS Approach
Yadav, H L; Toki, H
2004-01-01
Recently it has been demonstrated, considering Ni and Ca isotopes as prototypes, that the relativistic mean-field plus BCS (RMF+BCS) approach wherein the single particle continuum corresponding to the RMF is replaced by a set of discrete positive energy states for the calculation of pairing energy provides a good approximation to the full relativistic Hartree-Bogoliubov (RHB) description of the ground state properties of the drip-line neutron rich nuclei. The applicability of RMF+BCS is essentially due to the fact that the main contribution to the pairing correlations is provided by the low-lying resonant states. General validity of this approach is demonstrated by the detailed calculations for the ground state properties of the chains of isotopes of O, Ca, Ni, Zr, Sn and Pb nuclei. The TMA and NL-SH force parameter sets have been used for the effective mean-field Lagrangian. Comprehensive results for the two neutron separation energy, rms radii, single particle pairing gaps and pairing energies etc. are pres...
Chandra Detects Relativistic Broad Absorption Lines from APM 08279+5255
Chartas, G; Garmire, G P; Gallagher, S C
2002-01-01
We report the discovery of X-ray broad absorption lines (BALs) from the BALQSO APM 08279+5255 originating from material moving at relativistic velocities with respect to the central source. The large flux magnification by a factor of ~ 100 provided by the gravitational lens effect combined with the large redshift (z = 3.91) of the quasar have facilitated the acquisition of the first high signal-to-noise X-ray spectrum of a quasar containing X-ray BALs. Our analysis of the X-ray spectrum of APM 08279+5255 places the rest-frame energies of the two observed absorption lines at 8.1 and 9.8 keV. The detection of each of these lines is significant at the > 99.9% confidence level based on the F-test. Assuming that the absorption lines are from Fe xxv Kalpha, the implied bulk velocities of the X-ray BALs are ~ 0.2c and ~ 0.4c, respectively. The observed high bulk velocities of the X-ray BALs combined with the relatively short recombination time-scales of the X-ray absorbing gas imply that the absorbers responsible fo...
Hadronization conditions in relativistic nuclear collisions and the QCD pseudo-critical line
Becattini, F; Stock, R; Bleicher, M
2016-01-01
We compare the reconstructed hadronization conditions in relativistic nuclear collisions in the nucleon-nucleon centre-of-mass energy range 4.7-2760 GeV in terms of temperature and baryon-chemical potential with lattice QCD calculations, by using hadronic multiplicities. We obtain hadronization temperatures and baryon chemical potentials with a fit to measured multiplicities by correcting for the effect of post-hadronization rescattering. The post-hadronization modification factors are calculated by means of a coupled hydrodynamical-transport model simulation under the same conditions of isothermal and isochemical decoupling as assumed in the statistical hadronization model fits to the data. The fit quality is considerably better than without rescattering corrections, as already found in previous work. The curvature of the obtained "true" hadronization pseudo-critical line kappa is found to be 0.0048+-0.0026, in agreement with lattice QCD estimates; the pseudo-critical temperature at vanishing mu_B is found t...
Iron line profiles in Suzaku spectra of bare Seyfert galaxies
Patrick, A R; Porquet, D; Markowitz, A G; Lobban, A P; Terashima, Y
2010-01-01
We methodically model the broad-band Suzaku spectra of a small sample of six 'bare' Seyfert galaxies: Ark 120, Fairall 9, MCG-02-14-009, Mrk 335, NGC 7469 and SWIFT J2127.4+5654. The analysis of bare Seyferts allows a consistent and physical modelling of AGN due to a weak amount of any intrinsic warm absorption, removing the degeneracy between the spectral curvature due to warm absorption and the red-wing of the Fe K region. Through effective modelling of the broad-band spectrum and investigating the presence of narrow neutral or ionized emission lines and reflection from distant material, we obtain an accurate and detailed description of the Fe K line region using models such as laor, kerrdisk and kerrconv. Results suggest that ionized emission lines at 6.7 keV and 6.97 keV (particularly Fe XXVI) are relatively common and the inclusion of these lines can greatly affect the parameters obtained with relativistic models i.e. spin, emissivity, inner radius of emission and inclination. Moderately broad components...
Variability of the Fe K line relativistic component in a sample of Seyfert 1 galaxies
De Marco, B L; Dadina, M; Palumbo, G G C
2006-01-01
We present the analysis of X-ray spectral varability made on a sample of 7 Seyfert 1 bright galaxies, using XMM-Newton data. From the "XMM-Newton Science Archive" we selected those bright Seyfert 1 showing one or more prominent flares in their 2-10 keV light curves. For each of them we extracted spectra in 3 different time intervals: before, during and after the flare. We fitted them with a simple power law and then shifted a narrow emission and absorption line template across the 2.5-10 keV data, in order to investigate the presence of line-like features with a confidence level greater than 99%. Some highly significant features were detected in 3 out of 7 sources studied. In particular, the 3 sources, namely PG 1211+143, NGC 4051 and NGC 3783, showed the presence of a variable emission feature in the 4.5-5.8 keV band, characterized by an increase of its intensity after the flare peak. Because of the observed variability pattern, this feature seems to be ascribable to a reverbered redshifted relativistic comp...
Discovery of the Red-Skewed K-alpha Iron Line in Cyg X-2 with Suzaku
Shaposhnikov, Nikolai; Titarchuk, Lev; Laurent, Philippe
2008-01-01
We report on the Suzaku observation of neutron star low-mass X-ray binary Cygnus X-2 which reveals strong iron K-alpha emission line. The line profile shows a prominent red wing extending down to 4 keV. This discovery increases the number of neutron star sources where red-skewed iron lines were observed and strongly suggests that this phenomenon is common not only in black holes but also in other types of compact objects. We examine the line profile by fitting it with the model which attributes its production to the relativistic effects due to disk reflection of X-ray radiation. We also apply an alternative model where the red wing is a result of down-scattering effect of the first order with respect to electron velocity in the wind outflow. Both models describe adequately the observed line profile. However, the X-ray variability in a state similar to that in the Suzaku observation which we establish by analysing RXTE observation favors the wind origin of the line formation.
Hadronization conditions in relativistic nuclear collisions and the QCD pseudo-critical line
Becattini, Francesco; Steinheimer, Jan; Stock, Reinhard; Bleicher, Marcus
2017-01-01
We compare the reconstructed hadronization conditions in relativistic nuclear collisions in the nucleon-nucleon centre-of-mass energy range 4.7-2760 GeV in terms of temperature and baryon-chemical potential with lattice QCD calculations, by using hadronic multiplicities. We obtain hadronization temperatures and baryon chemical potentials with a fit to measured multiplicities by correcting for the effect of post-hadronization rescattering. The post-hadronization modification factors are calculated by means of a coupled hydrodynamical-transport model simulation under the same conditions of approximate isothermal and isochemical decoupling as assumed in the statistical hadronization model fits to the data. The fit quality is considerably better than without rescattering corrections, as already found in previous work. The curvature of the obtained "true" hadronization pseudo-critical line κ is found to be 0.0048 ± 0.0026, in agreement with lattice QCD estimates; the pseudo-critical temperature at vanishing μB is found to be 164.3 ± 1.8 MeV.
Relativistic positioning: errors due to uncertainties in the satellite world lines
Puchades, Neus
2014-01-01
Global navigation satellite systems use appropriate satellite constellations to get the coordinates of an user -close to Earth- in an almost inertial reference system. We have simulated both GPS and GALILEO constellations. Uncertainties in the satellite world lines lead to dominant positioning errors. In this paper, a detailed analysis of these errors is developed inside a great region surrounding Earth. This analysis is performed in the framework of the so-called relativistic positioning systems. Our study is based on the Jacobian, J, of the transformation giving the emission coordinates in terms of the inertial ones. Around points of vanishing J, positioning errors are too large. We show that, for any 4-tuple of satellites, the points with J=0 are located at distances, D, from the Earth centre greater than about 2R/3, where R is the radius of the satellite orbits which are assumed to be circumferences. Our results strongly suggest that, for D-distances greater than 2R/3 and smaller than 100000 km, a rather ...
Variable Iron K-alpha Lines in Seyfert 1 Galaxies
Weaver, K A; Yaqoob, T
2001-01-01
We find that variability of the iron K-alpha line is common in Seyfert 1 galaxies. Using data from the ASCA archive for objects that have been observed more than once during the mission, we study the time-averaged spectra from individual observations, thereby probing variability on timescales that range from days to years. Since the statistics of the data do not warrant searches for line variability in terms of a complex physical model, we use a a simple Gaussian to model the gross shape of the line, and then use the centroid energy, intensity and equivalent width as robust indicators of changes in the line profile. We find that ~70% of Seyfert 1s (ten out of fifteen) show variability in at least one of these parameters: the centroid energy, intensity, and equivalent width vary in six, four, and eight sources respectively. Due to the low S/N, limited sampling and time averaging, we consider these results to represent lower limits to the rate of incidence of variability. In most cases changes in the line do no...
Iron Kα line of Kerr black holes with scalar hair
Ni, Yueying; Zhou, Menglei; Cárdenas-Avendaño, Alejandro; Bambi, Cosimo; Herdeiro, Carlos A. R.; Radu, Eugen
2016-07-01
Recently, a family of hairy black holes in 4-dimensional Einstein gravity minimally coupled to a complex, massive scalar field was discovered [1]. Besides the mass M and spin angular momentum J, these objects are characterized by a Noether charge Q, measuring the amount of scalar hair, which is not associated to a Gauss law and cannot be measured at spatial infinity. Introducing a dimensionless scalar hair parameter q, ranging from 0 to 1, we recover (a subset of) Kerr black holes for q = 0 and a family of rotating boson stars for q = 1. In the present paper, we explore the possibility of measuring q for astrophysical black holes with current and future X-ray missions. We study the iron Kα line expected in the reflection spectrum of such hairy black holes and we simulate observations with Suzaku and eXTP. As a proof of concept, we point out, by analyzing a sample of hairy black holes, that current observations can already constrain the scalar hair parameter q, because black holes with q close to 1 would have iron lines definitively different from those we observe in the available data. We conclude that a detailed scanning of the full space of solutions, together with data from the future X-ray missions, like eXTP, will be able to put relevant constraints on the astrophysical realization of Kerr black holes with scalar hair.
Qin, Y P
2003-01-01
We display by numerical calculation how rest frame spectral lines appear in the observed spectrum of gamma-ray bursts due to the Doppler effect in the fireball framework. The analysis shows that: a) in the spectrum of a relativistically expanding fireball, all rest frame lines would shift to higher energy bands and would be significantly smoothed; b) rest frame weak narrow emission lines as well as narrow absorption lines and absorption line forests would be smoothed and would hardly be detectable; c) the features of rest frame broad emission lines as well as both strong and weak broad absorption lines would remain almost unchanged and therefore would be easier to detect; d) deep gaps caused by rest frame broad absorption lines would be significantly filled; e) a rest frame emission line forest would form a single broad line feature; f) the observed relative width of the rest frame very narrow line would approach $ 0.162$; g) when the Lorentz factor $\\Gamma $ is large enough, the observed line frequency $\
A panchromatic view of relativistic jets in gamma-ray emitting narrow-line Seyfert 1 galaxies
D'Ammando, F; Finke, J; Giroletti, M; Larsson, J
2015-01-01
Before the launch of the Fermi satellite only two classes of Active Galactic Nuclei (AGN) were known to generate relativistic jets and thus to emit up to the gamma-ray energy range: blazars and radio galaxies, both hosted in giant elliptical galaxies. The first four years of observations by the Large Area Telescope (LAT) on board Fermi confirmed that these two populations represent the most numerous identified sources in the extragalactic gamma-ray sky, but the discovery of variable gamma-ray emission from 5 radio-loud Narrow-Line Seyfert 1 (NLSy1) galaxies revealed the presence of a possible emerging third class of AGN with relativistic jets. Considering that NLSy1 are thought to be hosted in spiral galaxies, this finding poses intriguing questions about the nature of these objects, the knowledge of the development of relativistic jets, and the evolution of radio-loud AGN. In this context, the study of the radio-loud NLSy1 from radio to gamma-rays has received increasing attention. Here we discuss the radio-...
Relativistic ab initio spectroscopy study of forbidden lines of singly ionized zinc
Dixit, Gopal; Sahoo, Bijaya K.; Chaudhuri, Rajat K.; Majumder, Sonjoy
2009-01-01
The ab initio calculation has been carried out to study the astrophysically important forbidden electromagnetic transition rates of singly ionized zinc (Zn II). Electron correlations are considered to all orders using coupled-cluster theory in the relativistic framework. Calculated excitation energi
Relativistic ab initio spectroscopy study of forbidden lines of singly ionized zinc
Dixit, Gopal; Sahoo, Bijaya K.; Chaudhuri, Rajat K.; Majumder, Sonjoy
2009-01-01
The ab initio calculation has been carried out to study the astrophysically important forbidden electromagnetic transition rates of singly ionized zinc (Zn II). Electron correlations are considered to all orders using coupled-cluster theory in the relativistic framework. Calculated excitation
Pawar, Pramod; Patil, Madhav; Misra, Ranjeev; Jogadand, Sharada
2016-01-01
We performed time resolved spectroscopy of 1H0707-495 and IRAS 13224-3809 using long XMM-Newton observations. These are strongly variable narrow line Seyfert 1 galaxies and show broad features around 1 keV that has been interpreted as relativistically broad Fe L$\\alpha$ lines. Such features are not clearly observed in other AGN despite sometimes having high iron abundance required by the best fitted blurred reflection models. Given the importance of these lines, we explore the possibility if rapid variability of spectral parameters may introduce broad bumps/dips artificially in the time averaged spectrum, which may then be mistaken as broadened lines. We tested this hypothesis by performing time resolved spectroscopy using long (> 100 ks) XMM-Newton observations and by dividing it into segments with typical exposure of few ks. We extracted spectra from each such segment and modelled using a two component phenomenological model consisting of a power law to represent hard component and a black body to represent...
Nowak, Michael A.; Hanke, Manfred; Trowbridge, Sarah N.; Markoff, Sera B.; Wilms, Joern; Pottschmidt, Katja; Coppi, Paolo; Maitra, Dipankar; Davis, Jhn E.; Tramper, Frank
2009-01-01
Using Suzaku and the Rossi X-ray Timing Explorer (RXTE), we have conducted a series of four simultaneous observations of the galactic black hole candidate Cyg X-1 in what were historically faint and spectrally hard "low states". Additionally, all of these observations occurred near superior conjunction with our line of sight to the X-ray source passing through the dense phases of the "focused wind" from the mass donating secondary. One of our observations was also simultaneous with observations by the Chandra-High Energy Transmission Grating (HETG). These latter spectra are crucial for revealing the ionized absorption due to the secondary s focused wind. Such absorption is present and must be accounted for in all four spectra. These simultaneous data give an unprecedented view of the 0.8-300 keV spectrum of Cyg X-1, and hence bear upon both corona and X-ray emitting jet models of black hole hard states. Three models fit the spectra well: coronae with thermal or mixed thermal/non-thermal electron populations, and jets. All three models require a soft component that we fit with a low temperature disk spectrum with an inner radius of only a few tens of GM/c2. All three models also agree that the known spectral break at 10 keV is not solely due to the presence of reflection, but each gives a different underlying explanation for the augmentation of this break. Thus whereas all three models require that there is a relativistically broadened Fe line, the strength and inner radius of such a line is dependent upon the specific model, thus making premature line-based estimates of the black hole spin in the Cyg X-1 system. We look at the relativistic line in detail, accounting for the narrow Fe emission and ionized absorption detected by HETG. Although the specific relativistic parameters of the line are continuum-dependent, none of the broad line fits allow for an inner disk radius that is > 40 GM/c(sup 2).
Young, A J; Fabian, A C
1998-01-01
Reynolds & Begelman (1997) have recently proposed a model in which the broad and extremely redshifted iron line seen during a deep minimum of the light curve of the Seyfert 1 galaxy MCG-6-30-15 originates from matter spiralling into a Schwarzschild black hole, contrary to previous claims that the black hole may be spinning rapidly (Iwasawa et al 1996; Dabrowski et al 1997). Here we calculate in detail the X-ray spectrum produced by their model using the full reflected continuum emission, including absorption features. This calculation takes into account the doppler and relativistic effects. For the range of parameters we consider, we find that the spectrum should show a large photoelectric absorption edge of iron, which is not seen in the data. The absorption edge is a consequence of the line emitting matter within the innermost stable orbit being highly ionized, and is largely independent of the parameters chosen for their model. If we restrict our attention to the 3-10 keV band we may effectively remove...
Iron K$\\alpha$ line of boson stars
Cao, Zheng; Zhou, Menglei; Bambi, Cosimo; Herdeiro, Carlos A R; Radu, Eugen
2016-01-01
The present paper is a sequel to our previous work [Y. Ni et al., JCAP 1607, 049 (2016)] in which we studied the iron K$\\alpha$ line expected in the reflection spectrum of Kerr black holes with scalar hair. These metrics are solutions of Einstein's gravity minimally coupled to a massive, complex scalar field. They form a continuous bridge between a subset of Kerr black holes and a family of rotating boson stars depending on one extra parameter, the dimensionless scalar hair parameter $q$, ranging from 0 (Kerr black holes) to 1 (boson stars). Here we study the limiting case $q=1$, corresponding to rotating boson stars. For comparison, spherical boson stars are also considered. We simulate observations with XIS/Suzaku. Using the fact that current observations are well fit by the Kerr solution and thus requiring that acceptable alternative compact objects must be compatible with a Kerr fit, we find that some boson star solutions are relatively easy to rule out as potential candidates to explain astrophysical bla...
Properties of liquid iron along the melting line up to Earth-core pressures.
Fomin, Yu D; Ryzhov, V N; Brazhkin, V V
2013-07-17
We report a molecular dynamics study of the transport coefficients and the infinite frequency shear modulus of liquid iron at high temperatures and high pressures. We observe a simultaneous rise of both the shear viscosity and the diffusion coefficient along the melting line and estimate whether liquid iron can vitrify under Earth-core conditions. We show that in the conditions of the model studied in our work iron demonstrates a moderate increase of viscosity along the melting line. It is also demonstrated that at the limit of high temperatures and high pressures the liquid iron behaves similarly to the soft sphere system with exponent n ≈ 4.6.
Porquet, D; Uttley, P; Turner, T J
2004-01-01
We present a spectral analysis of the Seyfert 1.8 ESO 113-G010 observed with XMM-Newton for 4 ks. The spectrum shows a soft excess below 0.7 keV and more interestingly a narrow emission Gaussian line at 5.4 keV (in its rest-frame), most probably originating from a redshifted iron Kalpha line. No significant line at or above 6.4 keV is found contrary to other objects showing redshifted lines, ruling out a strong blue-wing to the line profile. The line is detected at 99% confidence, from performing Monte Carlo simulations which fully account for the range of energies where a narrow iron line is likely to occur. The energy of the line could indicate emission from relativistic (0.17 - 0.23 c) ejected matter moving away from the observer, as proposed for Mrk 766 by Turner et al. (2004). Alternatively, the emission from a narrow annulus at the surface of the accretion disk.
Microarray analysis of iron deficiency chlorosis in near-isogenic soybean lines
Cianzio Silvia R
2007-12-01
Full Text Available Abstract Background Iron is one of fourteen mineral elements required for proper plant growth and development of soybean (Glycine max L. Merr.. Soybeans grown on calcareous soils, which are prevalent in the upper Midwest of the United States, often exhibit symptoms indicative of iron deficiency chlorosis (IDC. Yield loss has a positive linear correlation with increasing severity of chlorotic symptoms. As soybean is an important agronomic crop, it is essential to understand the genetics and physiology of traits affecting plant yield. Soybean cultivars vary greatly in their ability to respond successfully to iron deficiency stress. Microarray analyses permit the identification of genes and physiological processes involved in soybean's response to iron stress. Results RNA isolated from the roots of two near isogenic lines, which differ in iron efficiency, PI 548533 (Clark; iron efficient and PI 547430 (IsoClark; iron inefficient, were compared on a spotted microarray slide containing 9,728 cDNAs from root specific EST libraries. A comparison of RNA transcripts isolated from plants grown under iron limiting hydroponic conditions for two weeks revealed 43 genes as differentially expressed. A single linkage clustering analysis of these 43 genes showed 57% of them possessed high sequence similarity to known stress induced genes. A control experiment comparing plants grown under adequate iron hydroponic conditions showed no differences in gene expression between the two near isogenic lines. Expression levels of a subset of the differentially expressed genes were also compared by real time reverse transcriptase PCR (RT-PCR. The RT-PCR experiments confirmed differential expression between the iron efficient and iron inefficient plants for 9 of 10 randomly chosen genes examined. To gain further insight into the iron physiological status of the plants, the root iron reductase activity was measured in both iron efficient and inefficient genotypes for plants
Karbhari Pawar, Pramod; Dewangan, Gulab Chand; Khushalrao Patil, Madhav; Misra, Ranjeev; Keshav Jogadand, Sharada
2016-11-01
We performed time resolved spectroscopy of 1H0707-495 and IRAS 13224-3809 using long XMM-Newton observations. These are strongly variable narrow line Seyfert 1 galaxies and show broad features around 1 keV that have been interpreted as relativistically broad Fe Lα lines. Such features are not clearly observed in other active galactic nuclei despite sometimes having high iron abundance required by the best fitted blurred reflection models. Given the importance of these lines, we explore whether the rapid variability of spectral parameters may introduce broad bumps/dips artificially in the time averaged spectrum, which may then be mistaken as broadened lines. We tested this hypothesis by performing time resolved spectroscopy using long (>100 ks) XMM-Newton observations and by dividing them into segments with typical exposures of a few ks. We extracted spectra from each such segment and modeled them using a two component phenomenological model consisting of a power law to represent the hard component and a black body to represent the soft emission. As expected, both the sources showed variations in the spectral parameters. Using these variation trends, we simulated model spectra for each segment and then co-added to get a combined simulated spectrum. In the simulated spectra, we found no broad features below 1 keV and in particular no deviation near 0.9 keV as seen in the real averaged spectra. This implies that the broad Fe Lα line that is seen in the spectra of these sources is not an artifact of the variation of spectral components and, hence, provides evidence that the line is indeed genuine.
Lyu, Ming; Sanna, Andrea; Homan, Jeroen; Belloni, Tomaso; Hiemstra, Beike
2014-01-01
We used six simultaneous XMM-Newton and Rossi X-ray Timing Explorer plus five Suzaku observations to study the continuum spectrum and the iron emission line in the neutron-star low-mass X-ray binary 4U 1636-53. We modelled the spectra with two thermal components (representing the accretion disc and boundary layer), a Comptonised component (representing a hot corona), and either a Gaussian or a relativistic line component to model an iron emission line at about 6.5 keV. For the relativistic line component we used either the diskline, laor or kyrline model, the latter for three different values of the spin parameter. The fitting results for the continuum are consistent with the standard truncated disc scenario. We also find that the flux and equivalent width of the iron line first increase and then decrease as the flux of the Comptonised component increases. This could be explained either by changes in the ionisation state of the accretion disc where the line is produced by reflection, or by light bending of th...
Selection of common bean lines with high grain yield and high grain calcium and iron concentrations
Nerinéia Dalfollo Ribeiro
2014-02-01
Full Text Available Genetic improvement of common bean nutritional quality has advantages in marketing and can contribute to society as a food source. The objective of this study was to evaluate the genetic variability for grain yield, calcium and iron concentrations in grains of inbred common bean lines obtained by different breeding methods. For this, 136 F7 inbred lines were obtained using the Pedigree method and 136 F7 inbred lines were obtained using the Single-Seed Descent (SSD method. The lines showed genetic variability for grain yield, and concentrations of calcium and iron independently of the method of advancing segregating populations. The Pedigree method allows obtaining a greater number of lines with high grain yield. Selection using the SSD method allows the identification of a larger number of lines with high concentrations of calcium and iron in grains. Weak negative correlations were found between grain yield and calcium concentration (r = -0.0994 and grain yield and iron concentration (r = -0.3926. Several lines show genetic superiority for grain yield and concentrations of calcium and iron in grains and their selection can result in new common bean cultivars with high nutritional quality.
Porquet, D.; Reeves, J. N.; Uttley, P.; Turner, T. J.
2004-11-01
We present a spectral analysis of the Seyfert 1.8 ESO 113-G010 observed with XMM-Newton for 4 ks. The spectrum shows a soft excess below 0.7 keV and more interestingly a narrow emission Gaussian line at 5.4 keV (in its rest-frame), most probably originating from a redshifted iron Kα line. No significant line at or above 6.4 keV is found contrary to other objects showing redshifted lines, ruling out a strong blue-wing to the line profile. The line is detected at 99% confidence, from performing Monte Carlo simulations which fully account for the range of energies where a narrow iron line is likely to occur. The energy of the line could indicate emission from relativistic (0.17-0.23 c) ejected matter moving away from the observer, as proposed for Mrk 766 by Turner et al. (\\cite{Tu04}, ApJ, 603, 62). Alternatively, the emission from a narrow annulus at the surface of the accretion disk is unlikely due to the very small inclination angle (i.e. less than 10°) required to explain the narrow, redshifted line in this intermediate Seyfert galaxy. However emission from a small, localized hot-spot on the disk, occurring within a fraction of a complete disk orbit, could also explain the redshifted line. This scenario would be directly testable in a longer observation, as one would see significant variations in the energy and intensity of the line within an orbital timescale.
Relativistic lines and reflection from the inner accretion disks around neutron stars
Cackett, E.M.; Miller, J.M.; Ballantyne, D.R.; Barret, D.; Bhattacharyya, S.; Boutelier, M.; Miller, M.C.; Strohmayer, T.E.; Wijnands, R.
2010-01-01
A number of neutron star low-mass X-ray binaries (LMXBs) have recently been discovered to show broad, asymmetric Fe K emission lines in their X-ray spectra. These lines are generally thought to be the most prominent part of a reflection spectrum, originating in the inner part of the accretion disk w
Convective shifts of iron lines in the spectrum of the solar photosphere
Sheminova, V A
2010-01-01
The influence of the convective structure of the solar photosphere on the shifts of spectral lines of iron was studied. Line profiles in the visible and infrared spectrum were synthesized with the use of 2-D time-dependent hydrodynamic solar model atmospheres. The dependence of line shifts on excitation potential, wavelength, and line strength was analyzed, along with the depression contribution functions. The line shifts were found to depend on the location of the line formation region in convective cells and the difference between the line depression contributions from granules and intergranular lanes. In visible spectrum the weak and moderate lines are formed deep in the photosphere. Their effective line formation region is located in the central parts of granules, which make the major contribution to the absorption of spatially unresolved lines. The cores of strong lines are formed in upper photospheric layers where is formed reversed granulation due to convection reversal and physical conditions change d...
X-ray spectra of Hercules X-1. I - Iron line fluorescence from a subrelativistic shell
Pravdo, S. H.; Becker, R. H.; Boldt, E. A.; Holt, S. S.; Serlemitsos, P. J.; Swank, J. H.
1977-01-01
The X-ray spectrum of Her X-1 was observed in the energy range from 2 to 24 keV from August 29 to September 3, 1975. Emission features are observed near the K-alpha iron-line energy which exhibit both broadening and a double line structure. The total luminosity in these features is about 4 by 10 to the 35th power ergs/s. Iron line fluorescence from an opaque cool (not exceeding 1 million K) shell of material at the Alfven surface provides the necessary luminosity in this feature. The double line structure and the line energy width can be due to Doppler shifts if the shell is forced to corotate with the pulsar at a radius of at least 800 million cm. Implications of this model regarding physical conditions near Her X-1 are discussed.
Evaluation and Application of Two High-Iron Transgenic Rice Lines Expressing a Pea Ferritin Gene
YE Hong-xai; LI Mei; Guo Ze-jian; Shu Qing-yao; xu Xiao-hui; BAO Jin-song; SHEN Sheng-quan
2008-01-01
A totaI of 105 transgenic rice lines independently transformed with a pea ferritin gene (Fer)were previously obtained.After seven generations of selfing and β-glucuronidase(GUS)assisted selection,82 transgenic lines with stable agronomic traits were got.Among the 82 transgenic lines,two high-iron transgenic rice lines Fer34 and Fer65,with the iron contents in the milled rice being 4.82 and 3.46 times of that of the wild type Xiushui 11,respectively were identified.In the two transgenic lines,the exogenous Fer gene was highly expressed,and inherited as a single locus.The transgene had no negative effect on the agronomic traits of rice plant,other mineral nutritional components,appearance quailty and eating quailty of the milled rice,indicating that these two lines were elite high-iron breeding lines.Furthermore,the practical application and further studies facilitating utilization of the two elite breeding lines were discussed.
Evershed flow observed in neutral and singly ionized iron lines
Khomenko, E; Shchukina, N; Diaz, A
2015-01-01
The amplitudes of the Evershed flow are measured using pairs of carefully selected FeI and FeII spectral lines located close in wavelength and registered simultaneously. A sunspot belonging to the NOAA 11582 group was scanned using the spectrograph of the German Vacuum Tower Telescope (Observatorio del Teide, Tenerife). Velocities were extracted from intensity profiles using the lambda-meter technique. The formation heights of the observed spectral lines were calculated using semi-empirical models of a bright and dark penumbral filament taking into account the sunspot location at the limb. Our objective is to compare azimuthally averaged amplitudes of the Evershed flow extracted from neutral and ion lines. We find measurable differences in the radial component of the flow. All five pairs of lines show the same tendency, with a few hundred m/s larger amplitude of the flow measured from FeI lines compared to FeII lines. This tendency is preserved at all photospheric heights and radial distances in the penumbra....
Evershed flow observed in neutral and singly ionized iron lines
Khomenko, E.; Collados, M.; Shchukina, N.; Díaz, A.
2015-12-01
The amplitudes of the Evershed flow are measured using pairs of carefully selected Fe i and Fe ii spectral lines that are close in wavelength and registered simultaneously. A sunspot belonging to the NOAA 11582 group was scanned using the spectrograph of the German Vacuum Tower Telescope (Observatorio del Teide, Tenerife). Velocities were extracted from intensity profiles using the λ-meter technique. The formation heights of the observed spectral lines were calculated using semi-empirical models of a bright and dark penumbral filament taking into account the sunspot location at the limb. Our objective is to compare azimuthally averaged amplitudes of the Evershed flow extracted from neutral and ion lines. We find measurable differences in the radial component of the flow. All five pairs of lines show the same tendency; the flow measured from the Fe i lines has an amplitude that is a few hundred ms-1 larger than that of the Fe ii lines. This tendency is preserved at all photospheric heights and radial distances in the penumbra. We discuss the possible origin of this effect.
Long term stability analysis of cast iron shaft linings after Coal Mine closure and flooding
Hadj-Hassen, F. [Ecole des Mines de Paris - CGES, 77 - Fontainebleau (France); Bienvenu, Y. [Ecole des Mines de Paris, CM, 91 - Evry (France); Noirel, J.F. [Charbonnages de France, DTN, 57 - Freyming Merlebach (France); Metz, M. [charbonnages de France, ESA, 57 - Freyming Merlebach (France)
2005-07-01
This paper presents the results of a study conducted to analyse the long term stability of the cast iron shaft lining after coal mine closure and flooding. The attention is mainly focused on the behaviour during the critical phase of flooding as well as the phase corresponding to the disappearance of the water pressure and the stabilization of the environment. This pluri-disciplinary study was conducted by a team combining specialists in rock mechanics who identified the main risks and the conditions of stability of the lining and specialists in metallurgy who studied the composition of the cast iron and its corrosion behaviour after exposure to mine water. (authors)
Laboratory grey cast iron continuous casting line with electromagnetic forced convection support
J. Szajnar
2010-07-01
Full Text Available The article describes the construction of a 20 mm diameter grey cast iron ingots continuous casting laboratory line. This line is made ofthree main units: melting unit (induction furnace, casting unit and the pulling unit. In order to improve the homogeneity of themicrostructure of ingots (by applying forced convection of liquid metal during the crystallization process in this case a crystallizer system generating the forced movement of liquid metal based on a system of electrical power windings of the AC specific frequency. Thissolution allowed to obtain a homogeneous microstructure of the continuous casting of cast iron EN-GJL-200 species.
A relativistic mean-ﬁeld study of magic numbers in light nuclei from neutron to proton drip-lines
T K Jha; M S Mehta; S K Patra; B K Raj; Raj K Gupta
2003-09-01
In an axially deformed relativistic mean-ﬁeld calculation of single-particle energy spectra of = 8 (Li–Mg) and = 14, 16 (C–Mg) isotonic chain and the one- and two-neutron separation energies of various isotopes of Li–Mg, new magic numbers are found to exist at = 6 and = 16 and/or = 14, which are in addition to the = 8 and = 20 magic numbers. In neutron-rich nuclei, the shell gap at = 6 is larger than at = 8 and a large gap is observed for = 16 or 14 for the neutron-rich and = 14 for proton-rich nuclei. Large shell gaps are also found to exist at = 14 and 16 or = 16 alone for nuclei near the -stability line. The above results are independent of the parameter sets TM2, NL3 and NL–SH used here. Similarly, new large shell gaps are predicted at = 6, 16 and/or 14 for protons.
Testa, U; Louache, F; Titeux, M; Thomopoulos, P; Rochant, H
1985-07-01
Picolinic acid, a metal chelating molecule, was administered to human erythroleukaemic cell lines (K 562 and HEL) that were grown in serum-containing media. Picolinic acid inhibited both iron uptake and cell growth. Furthermore, picolinic acid was shown to markedly decrease the level of ferritin in the cells. In spite of the inhibition of cell growth, picolinic acid induced a marked increase in the transferrin-binding capacity of the cells. This phenomenon was due to a two-five-fold enhancement of the rate of transferrin receptor biosynthesis. Other iron-chelating compounds, capable of reducing the level of intracellular iron, also elicited a marked enhancement of the transferrin-binding capacity of the cells. However, the addition of iron, as ferric ammonium citrate, in the culture medium elicited a marked increase in the level of ferritin and a strong decrease in the transferrin-binding capacity of the cells. On the basis of these data we propose that a feed-back mechanism is involved in the regulation of transferrin receptors: when the cells accumulate iron they decrease the number of transferrin receptors in order to prevent further accumulation of iron; when no or low iron is available to the cells, the number of transferrin receptors markedly increases as a compensatory mechanism.
Isolation, analytical measurements, and cell line studies of the iron-bryostatin-1 complex.
Plummer, Sydney; Manning, Thomas; Baker, Tess; McGreggor, Tysheon; Patel, Mehulkumar; Wylie, Greg; Phillips, Dennis
2016-05-15
Bryostatin-1 is a marine natural product that has demonstrated medicinal activity in pre-clinical and clinical trials for the treatment of cancer, Alzheimer's disease, effects of stroke, and HIV. In this study, iron-bryostatin-1 was obtained using a pharmaceutical aquaculture technique developed by our lab that cultivates marine bacteria for marine natural product extraction. Analytical measurements (1)H and (13)C NMR, mass spectrometry, and flame atomic absorption were utilized to confirm the presence of an iron-bryostatin-1 complex. The iron-bryostatin-1 complex produced was then tested against the National Cancer Institute's 60 cell line panel. Adding iron to bryostatin-1 lowered the anti-cancer efficacy of the compound. Copyright © 2016 Elsevier Ltd. All rights reserved.
Laboratory grey cast iron continuous casting line with electromagnetic forced convection support
2010-01-01
The article describes the construction of a 20 mm diameter grey cast iron ingots continuous casting laboratory line. This line is made ofthree main units: melting unit (induction furnace), casting unit and the pulling unit. In order to improve the homogeneity of themicrostructure of ingots (by applying forced convection of liquid metal during the crystallization process) in this case a crystallizer system generating the forced movement of liquid metal based on a system of electrical power win...
Discoveries of Diffuse Iron Line Sources from the Sgr B Region
Koyama, K; Hyodo, Y; Matsumoto, H; Tsuru, T G; Maeda, Y; Murakami, H; Yamauchi, S; Kissel, S E; Soong, C Y; Koyama, Katsuji; Inui, Tatsuya; Hyodo, Yoshiaki; Matsumoto, Hironori; Tsuru, Takeshi Go; Maeda, Yoshitomo; Murakami, Hiroshi; Yamauchi, Shigeo; Kissel, Steven E.; Soong, Chan Yang
2006-01-01
The radio complex Sgr B region is observed with the X-Ray Imaging Spectrometers (XIS) on board Suzaku. This region exhibits diffuse iron lines at 6.4, 6.7 and 6.9 keV, which are K$\\alpha$ lines of Fe \\emissiontype{I} (neutral iron), Fe\\emissiontype{XXV} (He-like iron) and Fe\\emissiontype{XXVI} (H-like iron), respectively. The high energy resolving power of the XIS provides the separate maps of the K-shell transition lines from Fe\\emissiontype{I} (6.4 keV) and Fe\\emissiontype{XXV} (6.7 keV). Although the 6.7 keV line is smoothly distributed over the Sgr B region, a local excess is found near at $(l, b) = (\\timeform {0D.61}, \\timeform{0D.01})$, possibly a new SNR. The plasma temperature is \\textit{kT} $\\sim$3 keV and the age is estimated to be around several$\\times10^{3}$ years. The 6.4 keV image is clumpy with local excesses nearby Sgr B2 and at $(l, b) = (\\timeform{0D.74}, -\\timeform{0D.09})$. Like Sgr B2, this excess may be another candidate of an X-ray reflection nebula (XRN).
Pereira, H S; Del Peloso, M J; Bassinello, P Z; Guimarães, C M; Melo, L C; Faria, L C
2014-08-28
The common bean is an important source of iron and zinc in humans. Increases in the contents of these minerals can combat mineral deficiencies, but these contents are influenced by environmental conditions. Thus, the objectives of this study were to investigate the interaction between common bean lines and water availability on iron and zinc contents (CFe and CZn, respectively), identify superior lines with stable CFe and CZn, and test for a genetic relationship between CFe and CZn. Six crop trials were performed using a randomized block design with three replications. The trials were performed during the winter sowing period for three different combinations of year and site in Brazil. For each combination, 53 lines were evaluated across two parallel trials; one trial was irrigated according to the crop requirements, and the other trial operated under a water deficit. Interaction was detected between lines and environments, and between lines and water availability for CFe and CZn. However, some lines exhibited high CFe and CZn in both conditions. Lines G 6492 and G 6490 exhibited high mean values, stability, and adaptability for both minerals. Other lines exhibited high CFe (Xamego) or CZn (Bambuí and Iapar 65). A moderate genetic correlation (0.62) between CFe and CZn was detected. Water availability during the common bean cycle had an effect on CFe and CZn; however, lines with high CFe and CZn in different conditions of water availability and environment were detected.
The Broad Iron K-alpha line of Cygnus X-1 as Seen by XMM-Newton in the EPIC-pn Modified Timing Mode
Duro, Refiz; Dauser, Thomas; Wilms, Jorn; Pottschmidt, Katja; Nowak, Michael A.; Fritz, Sonja; Kendziorra, Eckhard; Kirsch, Marcus G. F.; Reynolds, Christopher S.; Staubert, Rudiger
2011-01-01
We present the analysis of the broadened, flourescent iron K(alpha) line in simultaneous XMM-Newton and RXTE data from the black hole Cygnus X-I. The XMM-Newton data were taken in a modified version of the Timing Mode of the EPIC-pn camera. In this mode the lower energy threshold of the instrument is increased to 2.8 keV to avoid telemetry drop outs due to the brightness of the source, while at the same time preserving the signal to noise ratio in the Fe K(alpha) band. We find that the best-fit spectrum consists of the sum of an exponentially cut-off power-law and relativistically smeared, ionized reflection. The shape of the broadened Fe K(alpha) feature is due to strong Compton broadening combined with relativistic broadening. Assuming a standard, thin accretion disk, the black hole is close to maximally rotating. Key words. X-rays: binaries - black hole physics - gravitation
Nilsen, Gørill
2016-08-01
Seal hunting and whaling have played an important part of people's livelihoods throughout prehistory as evidenced by rock carvings, remains of bones, artifacts from aquatic animals and hunting tools. This paper focuses on one of the more elusive resources relating to such activities: marine mammal blubber. Although marine blubber easily decomposes, the organic material has been documented from the Mesolithic Period onwards. Of particular interest in this article are the many structures in Northern Norway from the Iron Age and in Finland on Kökar, Åland, from both the Bronze and Early Iron Ages in which these periods exhibited traits interpreted as being related to oil rendering from marine mammal blubber. The article discusses methods used in this oil production activity based on historical sources, archaeological investigations and experimental reconstruction of Iron Age slab-lined pits from Northern Norway.
K$\\alpha$ iron line profile from accretion disks around regular and singular exotic compact objects
Bambi, Cosimo
2013-01-01
The nature of the super-massive black hole candidates in galactic nuclei can be tested by analyzing the profile of the K$\\alpha$ iron line observed in their X-ray spectrum. In this paper, we consider the possibility that the spacetime in the immediate vicinity of these objects may be described by some non vacuum exact solutions of Einstein's equations resulting as the end-state of gravitational collapse. The vacuum far away portion of the spacetime is described by the Schwarzschild metric, while the interior part may be either regular or have a naked singularity at the center. The iron line generated around this class of objects has specific features, which can be used to distinguish such objects from Kerr black holes. In particular, their iron line cannot have the characteristic low-energy tail of the line generated from accretion disks around fast-rotating Kerr black holes. We can thus conclude that the super-massive black hole candidates whose spin parameter has been estimated to be close to 1 assuming the...
Iron and Nickel Line Diagnostics for the Galactic Center Diffuse Emission
Koyama, K; Inui, T; Nakajima, H; Matsumoto, H; Tsuru, T G; Takahashi, T; Maeda, Y; Yamazaki, N; Murakami, H; Yamauchi, S; Tsuboi, Y; Senda, A; Kataoka, J; Takahashi, H; Holt, S S; Brown, G V; Koyama, Katsuji; Hyodo, Yoshiaki; Inui, Tatsuya; Nakajima, Hiroshi; Matsumoto, Hironori; Tsuru, Takeshi Go; Takahashi, Tadayuki; Maeda, Yoshitomo; Yamazaki, Noriko; Murakami, Hiroshi; Yamauchi, Shigeo; Tsuboi, Yohko; Senda, Atsushi; Kataoka, Jun; Takahashi, Hiromitsu; Holt, Stephen S; Brown, Gregory V
2006-01-01
We have observed the diffuse X-ray emission from the Galactic center (GC) using the X-ray Imaging Spectrometer (XIS) on Suzaku. The high-energy resolution and the low-background orbit provide excellent spectra of the GC diffuse X-rays (GCDX). The XIS found many emission lines in the GCDX near the energy of K-shell transitions of iron and nickel. The most pronounced features are FeI K alpha at 6.4 keV and K-shell absorption edge at 7.1 keV, which are from neutral and/or low ionization states of iron, and the K-shell lines at 6.7 keV and 6.9 keV from He-like (FeXXV K alpha) and hydrogenic (FeXXVI Ly alpha) ions of iron. In addition, K alpha lines from neutral or low ionization nickel (NiI K alpha) and He-like nickel (NiXXVII K alpha), and FeI K beta, FeXXV K beta, FeXXVI Ly beta, FeXXV K gamma and FeXXVI Ly gamma are detected for the first time. The line center energies and widths of FeXXV K alpha and FeXXVI Ly alpha favor a collisional excitation (CE) plasma for the origin of the GCDX. The electron temperature...
Zhang Lei; Kashiwakura, Shunsuke; Wagatsuma, Kazuaki, E-mail: wagatuma@imr.tohoku.ac.jp
2011-11-15
A Boltzmann plot for many iron atomic lines having excitation energies of 3.3-6.9 eV was investigated in glow discharge plasmas when argon or neon was employed as the plasma gas. The plot did not show a linear relationship over a wide range of the excitation energy, but showed that the emission lines having higher excitation energies largely deviated from a normal Boltzmann distribution whereas those having low excitation energies (3.3-4.3 eV) well followed it. This result would be derived from an overpopulation among the corresponding energy levels. A probable reason for this is that excitations for the high-lying excited levels would be caused predominantly through a Penning-type collision with the metastable atom of argon or neon, followed by recombination with an electron and then stepwise de-excitations which can populate the excited energy levels just below the ionization limit of iron atom. The non-thermal excitation occurred more actively in the argon plasma rather than the neon plasma, because of a difference in the number density between the argon and the neon metastables. The Boltzmann plots yields important information on the reason why lots of Fe I lines assigned to high-lying excited levels can be emitted from glow discharge plasmas. - Highlights: Black-Right-Pointing-Pointer This paper shows the excitation mechanism of Fe I lines from a glow discharge plasma. Black-Right-Pointing-Pointer A Boltzmann distribution is studied among iron lines of various excitation levels. Black-Right-Pointing-Pointer We find an overpopulation of the high-lying energy levels from the normal distribution. Black-Right-Pointing-Pointer It is caused through Penning-type collision of iron atom with argon metastable atom.
Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. Iron is also part of many other proteins and ...
... of iron stored in the body become low, iron deficiency anemia sets in. Red blood cells become smaller and ... from the lungs throughout the body. Symptoms of iron deficiency anemia include tiredness and lack of energy, GI upset, ...
Alejandro Cárdenas-Avendaño
2016-09-01
Full Text Available The recent announcement of the detection of gravitational waves by the LIGO/Virgo Collaboration has opened a new window to test the nature of astrophysical black holes. Konoplya & Zhidenko have shown how the LIGO data of GW 150914 can constrain possible deviations from the Kerr metric. In this letter, we compare their constraints with those that can be obtained from accreting black holes by fitting their X-ray reflection spectrum, the so-called iron line method. We simulate observations with eXTP, a next generation X-ray mission, finding constraints much stronger than those obtained by Konoplya & Zhidenko. Our results can at least show that, contrary to what is quite commonly believed, it is not obvious that gravitational waves are the most powerful approach to test strong gravity. In the presence of high quality data and with the systematics under control, the iron line method may provide competitive constraints.
Cardenas-Avendano, Alejandro; Bambi, Cosimo
2016-01-01
The recent announcement of the detection of gravitational waves by the LIGO/Virgo collaboration has opened a new window to test the nature of astrophysical black holes. Konoplya & Zhidenko have shown how the LIGO data of GW 150914 can constrain possible deviations from the Kerr metric. In this letter, we compare their constraints with those that can be obtained from accreting black holes by fitting their reflected X-ray spectrum, the so-called iron line method. We simulate observations with eXTP, a next generation X-ray mission, finding constraints much stronger than those obtained by Konoplya & Zhidenko. Our results can at least show that, contrary to what is quite commonly believed, it is not obvious that gravitational waves are the most powerful approach to test strong gravity. In the presence of high quality data and with the systematics under control, the iron line method may provide competitive constraints.
Chandra X-ray Observations of NGC 4258: Iron Absorption Lines from the Nucleus
Young, A J
2004-01-01
We report sub-arcsecond resolution X-ray imaging spectroscopy of the low luminosity active galactic nucleus of NGC 4258 and its immediate surroundings with the Chandra X-ray Observatory. NGC 4258 was observed four times, with the first two observations separated by one month, followed over a year later by two consecutive observations. The spectrum of the nucleus is well described by a heavily absorbed, hard X-ray power law of variable luminosity, plus a constant, thermal soft X-ray component. We do not detect an iron K alpha emission line with the upper limit to the equivalent width of a narrow, neutral iron line ranging between 94 and 887 eV (90% confidence) for the different observations. During the second observation on 2000-04-17, two narrow absorption features are seen with >99.5% confidence at ~6.4 keV and ~6.9 keV, which we identify as resonant absorption lines of Fe XVIII - Fe XIX K alpha and Fe XXVI K alpha, respectively. In addition, the 6.9 keV absorption line is probably variable on a timescale of...
Suzaku Monitoring of the Iron K Emission Line in the Type 1 AGN NGC 5548
Liu, Yuan; McHardy, Ian M; Grupe, Dirk; Wilkes, Belinda J; Reeves, James; Brickhouse, Nancy; Krongold, Yair; Mathur, Smita; Minezaki, Takeo; Nicastro, Fabrizio; Yoshii, Yuzuru; Zhang, Shuang Nan
2010-01-01
We present 7 sequential weekly observations of NGC 5548 conducted in 2007 with the \\textit{Suzaku} X-ray Imaging Spectrometer (XIS) in the 0.2-12 keV band and Hard X-ray Detector (HXD) in 10-600 keV band. The iron K$\\alpha$ line is well detected in all seven observations and K$\\beta$ line is also detected in four observations. In this paper, we investigate the origin of the Fe K lines using both the width of the line and the reverberation mapping method. With the co-added XIS and HXD spectra, we identify Fe K$\\alpha$ and K$\\beta$ line at 6.396$_{-0.007}^{+0.009}$ keV and 7.08$_{-0.05}^{+0.05}$ keV, respectively. The width of line obtained from the co-added spectra is 38$_{-18}^{+16}$ eV ($\\textrm{FWHM}=4200_{-2000}^{+1800}$ km/s) which corresponds to a radius of 20$_{-10}^{+50}$ light days, for the virial production of $1.220\\times10^7$ M$_{\\odot}$ in NCG 5548. To quantitatively investigate the origin of the narrow Fe line by the reverberation mapping method, we compare the observed light curves of Fe K$\\alph...
Hansen, Jakob Bondo; Moen, I W; Mandrup-Poulsen, T
2014-01-01
The interest in the role of ferrous iron in diabetes pathophysiology has been revived by recent evidence of iron as an important determinant of pancreatic islet inflammation and as a biomarker of diabetes risk and mortality. The iron metabolism in the β-cell is complex. Excess free iron is toxic......, but at the same time, iron is required for normal β-cell function and thereby glucose homeostasis. In the pathogenesis of diabetes, iron generates reactive oxygen species (ROS) by participating in the Fenton chemistry, which can induce oxidative damage and apoptosis. The aim of this review is to present...... and discuss recent evidence, suggesting that iron is a key pathogenic factor in both type 1 and type 2 diabetes with a focus on inflammatory pathways. Pro-inflammatory cytokine-induced β-cell death is not fully understood, but may include iron-induced ROS formation resulting in dedifferentiation by activation...
Iron K Line Variability in the Low-Luminosity AGN NGC 4579
Terashima, Yuichi; Ho, Luis C.; Ptak, Andrew F.; Yaqoob, Tahir; Kunieda, Hideyo; Misaki, Kazutami; Serlemitsos, Peter J.; White, Nicholas E. (Technical Monitor)
2000-01-01
We present results of new ASCA observations of the low-luminosity AGN (LLAGN) NGC 4579 obtained in 1998 December 18 and 28, and we report on detection of variability of an iron K emission line. The X-ray luminosities in the 2-10 keV band for the two observations are nearly identical, L(sub X) approximately = 2 x 10(exp 4l) ergs/s, but they are approximately 35% larger than that measured in 1995 July by Terashima et al. (1998). An Fe K emission line is detected at 6.39 +/- 0.09 keV (source rest frame) which is lower than the line energy 6.73(sup +0.13, sub -0.12) keV in the 1995 observation. If we fit the Fe lines with a blend of two Gaussians centered at 6.4 keV and 6.73 KeV, the intensity of the 6.7 keV line decreased, while the intensity of the 6.4 keV line increased, within an interval of 3.5 years. This variability rules out thermal plasmas in the host galaxy as the origin of the ionized Fe line in this LLAGN. The detection and variability of the 6.4 keV line suggest that an optically thick standard accretion disk is present and subtends a large solid angle viewed from the nucleus at the Eddington ratio of L(sub Bol)/L(sub Eddington) approximately 2 x 10(exp -3) (Ho 1999). A broad disk-line profile is not clearly seen and the structure of the innermost part of accretion disk remains unclear.
Demianski, Marek
2013-01-01
Relativistic Astrophysics brings together important astronomical discoveries and the significant achievements, as well as the difficulties in the field of relativistic astrophysics. This book is divided into 10 chapters that tackle some aspects of the field, including the gravitational field, stellar equilibrium, black holes, and cosmology. The opening chapters introduce the theories to delineate gravitational field and the elements of relativistic thermodynamics and hydrodynamics. The succeeding chapters deal with the gravitational fields in matter; stellar equilibrium and general relativity
The curious time lags of PG 1244+026: discovery of the iron K reverberation lag
Kara, E.; Cackett, E.M.; Fabian, A.C.; Reynolds, C.; Uttley, P.
2014-01-01
High-frequency iron K reverberation lags, where the red wing of the line responds before the line centroid, are a robust signature of relativistic reflection off the inner accretion disc. In this Letter, we report the discovery of the Fe K lag in PG 1244+026 from ∼120 ks of data (one orbit of the
Broad iron L-line and X-ray reverberation in 1H0707-495
Zoghbi, A; Uttley, P; Miniutti, G; Gallo, L; Reynolds, C; Miller, J; Ponti, G
2009-01-01
A detailed analysis of a long XMM-Newton observation of the Narrow Line Seyfert 1 galaxy 1H0707-495 is presented, including spectral fitting, spectral variability and timing studies. The two main features in the spectrum are the drop at ~ 7 keV and a complex excess below 1 keV. These are well described by two broad, K and L, iron lines. Alternative models based on absorption, although they may fit the high energy drop, cannot account for the 1 keV complexity and the spectrum as a whole. Spectral variability shows that the spectrum is composed of at least two components, which are interpreted as a power-law dominating between 1-4 keV, and a reflection component outside this range. The high count rate at the iron L energies has enabled us to measure a significant soft lag of ~ 30 s between 0.3-1 and 1-4 keV, meaning that the direct hard emission leads the reflected emissions. We interpret the lag as a reverberation signal originating within a few gravitational radii of the black hole.
The effect of frame dragging on the iron K alpha line in X-ray binaries
Ingram, Adam
2012-01-01
The clear characteristic timescale picked out by the low frequency quasi-periodic oscillations (QPOs) seen in many black hole and neutron star binaries has the potential to provide a very powerful diagnostic of the inner regions of the accretion flow. However, this potential cannot be realised without a quantitative model for the QPO. We have recently shown that the same truncated disc/hot inner flow geometry which is used to interpret the spectral transitions can also directly produce the QPO from Lense-Thirring (vertical) precession of the hot inner flow. This correctly predicts both the frequency and spectrum of the QPO, and the tight correlation of these properties with the total spectrum of the source via a changing truncation radius between the disc and hot flow. This model predicts a unique iron line signature as a vertically tilted flow illuminates different azimuths of the disc as it precesses. The iron line arising from this rotating illumination is blue shifted when the flow irradiates the approach...
Testing the Kerr metric with the iron line and the KRZ parametrization
Ni, Yueying; Bambi, Cosimo
2016-01-01
The spacetime geometry around astrophysical black holes is supposed to be well approximated by the Kerr metric, but deviations from the Kerr solution are predicted in a number of scenarios involving new physics. Broad iron K$\\alpha$ lines are commonly observed in the X-ray spectrum of black holes and originate by X-ray fluorescence of the inner accretion disk. The profile of the iron line is sensitively affected by the spacetime geometry in the strong gravity region and can be used to test the Kerr black hole hypothesis. In this paper, we extend previous work in the literature. In particular: i) as test-metric, we employ the parametrization recently proposed by Konoplya, Rezzolla, and Zhidenko, which has a number of subtle advantages with respect to the existing approaches; ii) we perform simulations with specific X-ray missions, and we consider NuSTAR as a prototype of current observational facilities and eXTP as an example of the next generation of X-ray observatories. We find a significant difference betwe...
miR-210 Targets Iron-Sulfur Cluster Scaffold Homologue in Human Trophoblast Cell Lines
Lee, Deug-Chan; Romero, Roberto; Kim, Jung-Sun; Tarca, Adi L.; Montenegro, Daniel; Pineles, Beth L.; Kim, Ernest; Lee, JoonHo; Kim, Sun Young; Draghici, Sorin; Mittal, Pooja; Kusanovic, Juan Pedro; Chaiworapongsa, Tinnakorn; Hassan, Sonia S.; Kim, Chong Jai
2011-01-01
This study was performed to assess the biological significance of miR-210 in preeclampsia and small-for-gestational-age (SGA) pregnancies. Placental miR-210 expression was evaluated by quantitative RT-PCR (RT-qPCR) in the following groups: i) appropriate-for-gestational-age pregnancies (n = 72), ii) preeclampsia (n = 52), iii) SGA (n = 66), and iv)preeclampsia with SGA (n = 31). The effects of hypoxia (1% O2) on miR-210 and iron-sulfur cluster scaffold homologue (ISCU) expressions and miR-210 binding to ISCU 3′ UTR were examined in Swan 71 and BeWo cell lines. Perls' reaction (n = 229) and electron microscopy (n = 3) were conducted to verify siderosis of trophoblasts. miR-210 expression was increased in preeclampsia and SGA cases and was decreased with birth weight and gestational age. In both cell lines, miR-210 was induced by hypoxia, whereas ISCU expression was decreased. The luciferase assay confirmed miR-210 binding to ISCU mRNA 3′ UTR. RNA interference knockdown of ISCU expression in Swan 71, but not in BeWo, cells resulted in autophagosomal and siderosomal iron accumulation and a fourfold decrease of Matrigel invasion (P = 0.004). Placental ISCU expression was decreased in preeclampsia (P = 0.002) and SGA (P = 0.002) cases. Furthermore, hemosiderin-laden trophoblasts were more frequent in the placental bed of preterm preeclampsia and/or SGA births than in control cases (48.7% versus 17.9%; P = 0.004). Siderosis of interstitial trophoblasts is a novel pathological feature of preeclampsia and SGA. The findings herein suggest that ISCU down-regulation by miR-210 perturbing trophoblast iron metabolism is associated with defective placentation. PMID:21801864
Comparative proteomic analysis of drug sodium iron chlorophyllin addition to Hep 3B cell line.
Zhang, Jun; Wang, Wenhai; Yang, Fengying; Zhou, Xinwen; Jin, Hong; Yang, Peng-yuan
2012-09-21
The human hepatoma 3B cell line was chosen as an experimental model for in vitro test of drug screening. The drugs included chlorophyllin and its derivatives such as fluo-chlorophyllin, sodium copper chlorophyllin, and sodium iron chlorophyllin. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) method was used in this study to obtain the primary screening results. The results showed that sodium iron chlorophyllin had the best LC(50) value. Proteomic analysis was then performed for further investigation of the effect of sodium iron chlorophyllin addition to the Hep 3B cell line. The proteins identified from a total protein extract of Hep 3B before and after the drug addition were compared by two-dimensional-gel-electrophoresis. Then 32 three-fold differentially expressed proteins were successfully identified by MALDI-TOF-TOF-MS. There are 29 unique proteins among those identified proteins. These proteins include proliferating cell nuclear antigen (PCNA), T-complex protein, heterogeneous nuclear protein, nucleophosmin, heat shock protein A5 (HspA5) and peroxiredoxin. HspA5 is one of the proteins which are involved in protecting cancer cells against stress-induced apoptosis in cultured cells, protecting them against apoptosis through various mechanisms. Peroxiredoxin has anti-oxidant function and is related to cell proliferation, and signal transduction. It can protect the oxidation of other proteins. Peroxiredoxin has a close relationship with cancer and can eventually become a disease biomarker. This might help to develop a novel treatment method for carcinoma cancer.
Miller, J M; in 't Zand, J J M; Reynolds, C S; Wijnands, R; Nowak, M A; Lewin, W H G
2002-01-01
Broad Fe K-alpha emission lines have recently been reported in a number of Galactic black holes. Such lines are useful accretion flow diagnostics because they may be produced at the inner accretion disk and shaped by relativistic effects, but in general they have only been observed at luminosities of L_X = 10^(37-38) erg/s in soft X-rays. The Galactic microquasar V4641 Sgr -- widely known for its 12.2 Crab (1.5-12 keV) outburst in 1999 September -- displayed low-level activity in 1999 March. BeppoSAX observed the source in this state and Fe K-alpha line emission was found (in 't Zand et al. 2000). In re-analyzing these data, we find strong evidence that the Fe K-alpha line profile is broadened. For the most likely values of the source distance and black hole mass measured by Orosz et al. (2001), our fits to the total spectrum indicate that the source was observed at a luminosity of L_X = 1.9 (+1.0, -0.8) * 10^(36) erg/s (2-10 keV), or L_(2-10)/L_(Eddington) = 1.8 (+0.9, -0.8) * 10^(-3). Advection-dominated ac...
Suzaku Observations of Iron K-lines from the Intracluster Medium of the Coma Cluster
Sato, Takuya; Ota, Naomi; Sato, Kosuke; Nakazawa, Kazuhiro; Sarazin, Craig L
2011-01-01
The Coma cluster was observed with an X-ray Imaging Spectrometer (XIS) onboard Suzaku in six pointings, including the central X-ray peak region, the 14'west offset region, 30'and 34'north-west offset regions, and 44'and 60'south-west offset regions. Owing to its lower background level, Suzaku has better sensitivity to Fe K-alpha lines than other satellites. Using precise Fe line measurements, we studied the temperature structure, possible bulk motions, and iron abundance distributions in the intracluster medium (ICM). The observed spectra were well-represented by a single-temperature model, and two- or three- temperature model did not improve chi-square substantially. The temperature, derived from K-alpha line ratios of H-like and He-like Fe, agree with those derived from the single-temperature model. Because the line ratio is a steep function of temperature, the consistency supports the accuracy of temperature measurements conducted with Suzaku. Within the 34'region, the redshift derived from the central ene...
Deriving precise parameters for cool solar-type stars. Optimizing the iron line list
Tsantaki, M; Adibekyan, V Zh; Santos, N C; Mortier, A; Israelian, G
2013-01-01
Temperature, surface gravity, and metallicitity are basic stellar atmospheric parameters necessary to characterize a star. We aim to improve the description of the spectroscopic temperatures especially for the cooler stars where the differences with the Infrared Flux Method are higher, as presented in previous work. Our spectroscopic analysis is based on the iron excitation and ionization balance, assuming Kurucz model atmospheres in LTE. The abundance analysis is determined using the code MOOG. We optimize the line list using a cool star with high resolution and high signal-to-noise spectrum, as a reference in order to check for weak, isolated lines. We test the quality of the new line list by re-deriving stellar parameters for 451 stars with high resolution and signal-to-noise HARPS spectra, that were analyzed in a previous work with a larger line list. The comparison in temperatures between this work and the latest IRFM shows that the differences for the cooler stars are significantly smaller and more homo...
Deriving precise parameters for cool solar-type stars. Optimizing the iron line list
Tsantaki, M.; Sousa, S. G.; Adibekyan, V. Zh.; Santos, N. C.; Mortier, A.; Israelian, G.
2013-07-01
Context. Temperature, surface gravity, and metallicitity are basic stellar atmospheric parameters necessary to characterize a star. There are several methods to derive these parameters and a comparison of their results often shows considerable discrepancies, even in the restricted group of solar-type FGK dwarfs. Aims: We want to check the differences in temperature between the standard spectroscopic technique based on iron lines and the infrared flux method (IRFM). We aim to improve the description of the spectroscopic temperatures especially for the cooler stars where the differences between the two methods are higher, as presented in a previous work. Methods: Our spectroscopic analysis was based on the iron excitation and ionization balance, assuming Kurucz model atmospheres in LTE. The abundance analysis was determined using the code MOOG. We optimized the line list using a cool star (HD 21749) with high resolution and high signal-to-noise spectrum, as a reference in order to check for weak, isolated lines. Results: We test the quality of the new line list by re-deriving stellar parameters for 451 stars with high resolution and signal-to-noise HARPS spectra, that were analyzed in a previous work with a larger line list. The comparison in temperatures between this work and the latest IRFM for the stars in common shows that the differences for the cooler stars are significantly smaller and more homogeneously distributed than in previous studies for stars with temperatures below 5000 K. Moreover, a comparison is presented between interferometric temperatures with our results that shows good agreement, even though the sample is small and the errors of the mean differences are large. We use the new line list to re-derive parameters for some of the cooler stars that host planets. Finally, we present the impact of the new temperatures on the [Cr i/Cr ii] and [Ti i/Ti ii] abundance ratios that previously showed systematic trends with temperature. We show that the slopes
Biswal, S K
2014-01-01
We study the isoscalar giant monopole resonance for drip-lines and super heavy nuclei in the frame work of a relativistic mean field theory with scaling approach. The well known extended Thomas-Fermi approximation in the non-linear $\\sigma$-$\\omega$ model is used to estimate the giant monopole excitation energy for some selected light spherical nuclei starting from the region of proton to neutron drip-lines. The application is extended to super heavy region for Z=114 and 120, which are predicted by several models as the next proton magic number beyond Z=82. We compared the excitation energy obtained by four successful force parameters NL1, NL3, NL3$^*$ and FSUGold. The monopole energy decreases toward the proton and neutron drip-lines in an isotopic chain for lighter mass nuclei contrary to a monotonous decrease for super heavy isotopes. The maximum and minimum monopole excitation energies are obtained for nuclei with minimum and maximum isospin, respectively in an isotopic chain.
Milisavljevic, D; Parrent, J T; Soderberg, A M; Fesen, R A; Mazzali, P; Maeda, K; Sanders, N E; Cenko, S B; Silverman, J M; Filippenko, A V; Kamble, A; Chakraborti, S; Drout, M R; Kirshner, R P; Pickering, T E; Kawabata, K; Hattori, T; Hsiao, E Y; Stritzinger, M D; Marion, G H; Vinko, J; Wheeler, J C
2014-01-01
We present ultraviolet, optical, and near-infrared observations of SN 2012ap, a broad-lined Type Ic supernova in the galaxy NGC 1729 that produced a relativistic and rapidly decelerating outflow without a gamma-ray burst signature. Photometry and spectroscopy follow the flux evolution from -13 to +272 days past the B-band maximum of -17.4 +/- 0.5 mag. The spectra are dominated by Fe II, O I, and Ca II absorption lines at ejecta velocities of 20,000 km/s that change slowly over time. Other spectral absorption lines are consistent with contributions from photospheric He I, and hydrogen may also be present at higher velocities (> 27,000 km/s). We use these observations to estimate explosion properties and derive a total ejecta mass of 2.7 Msolar, a kinetic energy of 1.0x10^{52} erg, and a 56Ni mass of 0.1-0.2 Msolar. Nebular spectra (t > 200d) exhibit an asymmetric double-peaked [OI] 6300,6364 emission profile that we associate with absorption in the supernova interior, although toroidal ejecta geometry is an al...
Komossa, S; Wang, T; Ajello, M; Ge, J; Greiner, J; Lü, H; Salvato, M; Saxton, R; Shan, H; Xu, D; Yuan, W
2008-01-01
We report the discovery of superstrong, fading, high-ionization iron line emission in the galaxy SDSSJ095209.56+214313.3 (SDSSJ0952+2143 hereafter), which must have been caused by an X-ray outburst of large amplitude. SDSSJ0952+2143 is unique in its strong multiwavelength variability; such a broadband emission-line and continuum response has not been observed before. The strong iron line emission is accompanied by unusual Balmer line emission with a broad base, narrow core and double-peaked narrow horns, and strong HeII emission. These lines, while strong in the SDSS spectrum taken in 2005, have faded away significantly in new spectra taken in December 2007. Comparison of SDSS, 2MASS, GALEX and follow-up GROND photometry reveals variability in the NUV, optical and NIR band. Taken together, these unusual observations can be explained by a giant outburst in the EUV--X-ray band, detected even in the optical and NIR. The intense and variable iron, Helium and Balmer lines represent the ``light echo'' of the flare,...
On the Origin of Broad Iron Lines in Neutron Star Low-mass X-ray Binaries
Chiang, Chia-Ying; Miller, Jon M; Barret, Didier; Fabian, Andy C; D'Ai, Antonino; Parker, Michael L; Bhattacharyya, Sudip; Burderi, Luciano; Di Salvo, Tiziana; Egron, Elise; Homan, Jeroen; Iaria, Rosario; Lin, Dacheng; Miller, M Coleman
2015-01-01
Broad Fe K emission lines have been widely observed in the X-ray spectra of black hole systems, and in neutron star systems as well. The intrinsically narrow Fe K fluorescent line is generally believed to be part of the reflection spectrum originating in an illuminated accretion disk, and broadened by strong relativistic effects. However, the nature of the lines in neutron star LMXBs has been under debate. We therefore obtained the longest, high-resolution X-ray spectrum of a neutron star LMXB to date with a 300 ks Chandra HETGS observation of Serpens X-1. The observation was taken under the "continuous clocking" mode and thus free of photon pile-up effects. We carry out a systematic analysis and find that the blurred reflection model fits the Fe line of Serpens X-1 significantly better than a broad Gaussian component does, implying that the relativistic reflection scenario is much preferred. Chandra HETGS also provides highest spectral resolution view of the Fe K region and we find no strong evidence for add...
Jiang, Jiachen; Bambi, Cosimo; Steiner, James F.
2016-06-01
The iron K α line commonly observed in the x-ray spectrum of black hole candidates is produced by x-ray fluorescence of the inner accretion disk. This line can potentially be quite a powerful tool to probe the spacetime geometry around these objects and test the Kerr black hole hypothesis. In a previous paper, we studied the ability to constrain possible deviations from the Kerr solution from the standard time-integrated iron line spectrum within the Cardoso-Pani-Rico framework. In the present work, we expand on that study and consider iron line reverberation mapping in the Cardoso-Pani-Rico framework. That is, we consider the time evolution of the iron line profile in response to fluctuations in the x-ray primary source. Our simulations clearly show that the time information in reverberation mapping can better constrain the background metric than the time-integrated approach, and this is true, notably, for the deformation parameter ɛ3r, which is only weakly informed by a time-integrated observation.
Jiang, Jiachen; Steiner, James F
2016-01-01
The iron K$\\alpha$ line commonly observed in the X-ray spectrum of black hole candidates is produced by X-ray fluorescence of the inner accretion disk. This line can potentially be quite a powerful tool to probe the spacetime geometry around these objects and test the Kerr black hole hypothesis. In a previous paper, we studied the ability to constrain possible deviations from the Kerr solution from the standard time-integrated iron line spectrum within the Cardoso-Pani-Rico framework. In the present work, we expand on that study and consider iron line reverberation mapping in the CPR framework. That is, we consider the time-evolution of the iron line profile in response to fluctuations in the X-ray primary source. Our simulations clearly show that the time information in reverberation mapping can better constrain the background metric than the time-integrated approach, and this is true, notably, for the deformation parameter $\\epsilon^r_3$, which is only weakly informed by a time-integrated observation.
Cyclotron lines in X-ray pulsars as a probe of relativistic plasmas in superstrong magnetic fields
Dal Fiume, D; Masetti, N; Orlandini, M; Palazzi, E; Del Sordo, S; Santangelo, A; Segreto, A; Oosterbroek, T; Parmar, A N; Frontera, Filippo; Masetti, Nicola; Orlandini, Mauro; Palazzi, Eliana; Sordo, Stefano Del; Santangelo, Andrea; Segreto, Alberto; Oosterbroek, Tim; Parmar, Arvind N.
2000-01-01
The systematic search for the presence of cyclotron lines in the spectra ofaccreting X-ray pulsars is being carried on with the BeppoSAX satellite sincethe beginning of the mission. These highly successful observations allowed thedetection of cyclotron lines in many of the accreting X-ray pulsars observed.Some correlations between the different measured parameters were found. Wepresent these correlations and discuss them in the framework of the currenttheoretical scenario for the X-ray emission from these sources.
Milisavljevic, D.; Margutti, R.; Parrent, J. T.; Soderberg, A. M.; Fesen, R. A.; Mazzali, P.; Maeda, K.; Sanders, N. E.; Cenko, S. B.; Silverman, J. M.
2014-01-01
We present ultraviolet, optical, and near-infrared observations of SN2012ap, a broad-lined Type Ic supernova in the galaxy NGC 1729 that produced a relativistic and rapidly decelerating outflow without a gamma-ray burst signature. Photometry and spectroscopy follow the flux evolution from -13 to +272 days past the B-band maximum of -17.4 +/- 0.5 mag. The spectra are dominated by Fe II, O I, and Ca II absorption lines at ejecta velocities of v approx. 20,000 km s(exp. -1) that change slowly over time. Other spectral absorption lines are consistent with contributions from photospheric He I, and hydrogen may also be present at higher velocities (v approx. greater than 27,000 km s(exp. -1)). We use these observations to estimate explosion properties and derive a total ejecta mass of 2.7 Solar mass, a kinetic energy of 1.0×1052 erg, and a (56)Ni mass of 0.1-0.2 Solar mass. Nebular spectra (t > 200 d) exhibit an asymmetric double-peaked [O I] lambda lambda 6300, 6364 emission profile that we associate with absorption in the supernova interior, although toroidal ejecta geometry is an alternative explanation. SN2012ap joins SN2009bb as another exceptional supernova that shows evidence for a central engine (e.g., black-hole accretion or magnetar) capable of launching a non-negligible portion of ejecta to relativistic velocities without a coincident gamma-ray burst detection. Defining attributes of their progenitor systems may be related to notable properties including above-average environmental metallicities of Z approx. greater than Solar Z, moderate to high levels of host-galaxy extinction (E(B -V ) > 0.4 mag), detection of high-velocity helium at early epochs, and a high relative flux ratio of [Ca II]/[O I] > 1 at nebular epochs. These events support the notion that jet activity at various energy scales may be present in a wide range of supernovae.
Milisavljevic, D.; Margutti, R.; Parrent, J. T.; Soderberg, A. M.; Sanders, N. E.; Kamble, A.; Chakraborti, S.; Drout, M. R.; Kirshner, R. P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fesen, R. A. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); Mazzali, P. [Astrophysics Research Institute, Liverpool John Moores University, Liverpool L3 5RF (United Kingdom); Maeda, K. [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Cenko, S. B. [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Silverman, J. M. [University of Texas at Austin, 1 University Station C1400, Austin, TX 78712-0259 (United States); Filippenko, A. V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Pickering, T. E. [Southern African Large Telescope, P.O. Box 9, Observatory 7935, Cape Town (South Africa); Kawabata, K. [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Hattori, T. [Subaru Telescope, National Astronomical Observatory of Japan, Hilo, HI 96720 (United States); Hsiao, E. Y. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Stritzinger, M. D., E-mail: dmilisav@cfa.harvard.edu [Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C (Denmark); and others
2015-01-20
We present ultraviolet, optical, and near-infrared observations of SN 2012ap, a broad-lined Type Ic supernova in the galaxy NGC 1729 that produced a relativistic and rapidly decelerating outflow without a gamma-ray burst signature. Photometry and spectroscopy follow the flux evolution from –13 to +272 days past the B-band maximum of –17.4 ± 0.5 mag. The spectra are dominated by Fe II, O I, and Ca II absorption lines at ejecta velocities of v ≈ 20,000 km s{sup –1} that change slowly over time. Other spectral absorption lines are consistent with contributions from photospheric He I, and hydrogen may also be present at higher velocities (v ≳ 27,000 km s{sup –1}). We use these observations to estimate explosion properties and derive a total ejecta mass of ∼2.7 M {sub ☉}, a kinetic energy of ∼1.0 × 10{sup 52} erg, and a {sup 56}Ni mass of 0.1-0.2 M {sub ☉}. Nebular spectra (t > 200 days) exhibit an asymmetric double-peaked [O I] λλ6300, 6364 emission profile that we associate with absorption in the supernova interior, although toroidal ejecta geometry is an alternative explanation. SN 2012ap joins SN 2009bb as another exceptional supernova that shows evidence for a central engine (e.g., black hole accretion or magnetar) capable of launching a non-negligible portion of ejecta to relativistic velocities without a coincident gamma-ray burst detection. Defining attributes of their progenitor systems may be related to notable observed properties including environmental metallicities of Z ≳ Z {sub ☉}, moderate to high levels of host galaxy extinction (E(B – V) > 0.4 mag), detection of high-velocity helium at early epochs, and a high relative flux ratio of [Ca II]/[O I] >1 at nebular epochs. These events support the notion that jet activity at various energy scales may be present in a wide range of supernovae.
Analysis of high iron rice lines reveals new miRNAs that target iron transporters in roots
Paul, Soumitra; Gayen, Dipak; Datta, Swapan K.; Datta, Karabi
2016-01-01
The present study highlights the molecular regulation of iron transport in soyFER1-overexpressing transgenic rice. Accumulation of iron in three different seed developmental stages, milk, dough, and mature, has been examined. The transgenic seeds of the milk stage showed significant augmentation of iron and zinc levels compared with wild-type seeds, and similar results were observed throughout the dough and mature stages. To investigate the regulation of iron transport, the role of miRNAs was studied in roots of transgenic rice. Sequencing of small RNA libraries revealed 153 known and 41 novel miRNAs in roots. Among them, 59 known and 14 novel miRNAs were found to be significantly expressed. miR166, miR399, and miR408 were identified as playing a vital role in iron uptake in roots of transgenic plants . Most importantly, four putative novel miRNAs, namely miR11, miR26, miR30, and miR31, were found to be down-regulated in roots of transgenic plants. For all these four novel miRNAs, natural resistance-associated macrophage protein 4 (NRAMP4), encoding a metal transporter, was predicted as a target gene. It is hypothesized that the NRAMP4 transporter is activated in roots of transgenic plants due to the lower abundance of its corresponding putative novel miRNAs. The relative transcript level of the NRAMP4 transcript was increased from 0.107 in the wild type to 65.24 and 55.39 in transgenic plants, which demonstrates the elevated amount of iron transport in transgenic plants. In addition, up-regulation of OsYSL15, OsFRO2, and OsIRT1 in roots also facilitates iron loading in transgenic seeds. PMID:27729476
Reeves, J N; Turner, T J
2004-01-01
We report on a short XMM-Newton observation of the radio-quiet Narrow Line Seyfert 1 PG 1402+261. The EPIC X-ray spectrum of PG 1402+261 shows a strong excess of counts between 6-9 keV in the rest frame. This feature can be modeled by an unusually strong (equivalent width 2 keV) and very broad (FWHM velocity of 110000 km/s) iron K-shell emission line. The line centroid energy at 7.3 keV appears blue-shifted with respect to the iron Kalpha emission band between 6.4-6.97 keV, while the blue-wing of the line extends to 9 keV in the quasar rest frame. The line profile can be fitted by reflection from the inner accretion disk, but an inclination angle of >60 deg is required to model the extreme blue-wing of the line. Furthermore the extreme strength of the line requires a geometry whereby the hard X-ray emission from PG 1402+261 above 2 keV is dominated by the pure-reflection component from the disk, while little or none of the direct hard power-law is observed. Alternatively the spectrum above 2 keV may instead b...
Thermal Iron K and Alpha: Line Emission from the X-Ray Binary GX 339-4
Xu, Y. D.; Zhang, S. N.; Zhang, X. L.; Liu, D. B.; Chen, L.; Xu, H. G.; You, J. H.
2003-01-01
The accretion rate of the black hole candidate X-ray binary GX 339-4 in the 'off' state is low, and an advection dominated accretion flow (ADAF) is present. Hydrogen-like and helium-like iron Kbalpha; emission lines at 6.7 and 6.95 keV from hot plasma of ADAF can be produced by recombination-cascade processes with moderately high intensities, which are markedly distinguished from the fluorescent iron Kα line at approximately 6.4 keV. We show that the observational features of GX 339-4 can be explained by the ADAF model, if the iron abundance is more than 10 times the solar value, though the reason for such a high abundance is still unclear. We suggest that the increase of the accretion rate makes GX 339-4 change from off, low, intermediate, to high and very high states, and the line center of iron Kbalpha; will therefore shift from approximately 6.83 to approximately 6.4 keV, i.e. to the fluorescent disc-line, since the disappearance of the ADAF due to its high accretion rate.
Testing the no-hair theorem with the continuum-fitting and the iron line methods: a short review
Bambi, Cosimo; Steiner, James F
2015-01-01
The continuum-fitting and the iron line methods are leading techniques capable of probing the spacetime geometry around astrophysical black hole candidates and testing the no-hair theorem. In the present paper, we review the two approaches, from the astrophysical models and their assumptions, to the constraining power with present and future facilities.
K-shell Emission of Neutral Iron Line from Sgr B2 Excited by Subrelativistic Protons
Dogiel, Vladimir; Koyama, Katsuji; Nobukawa, Masayoshi; Cheng, Kwong-Sang
2011-01-01
We investigated the emission of K$\\alpha$ iron line from the massive molecular clouds in the Galactic center (GC). We assume that at present the total flux of this emission consists of time variable component generated by primary X-ray photons ejected by Sagittarius A$^\\ast$ (Sgr A$^\\ast$) in the past and a relatively weak quasi-stationary component excited by impact of protons which were generated by star accretion onto the central black hole. The level of background emission was estimated from a rise of the 6.4 keV line intensity in the direction of several molecular clouds, that we interpreted as a stage when the X-ray front ejected by Sgr A$^\\ast$ entered into these clouds. The 6.4 keV emission before this intensity jump we interpreted as emission generated by subrelativistic cosmic rays there. The cross-section of K$\\alpha$ vacancies produced by protons differs from that of electrons or X-rays. Therefore, we expect that this processes can be distinguished from the analysis of the equivalent width of the ...
Reeves, J. N.; Porquet, D.; Turner, T. J.
2004-11-01
We report on a short XMM-Newton observation of the radio-quiet narrow-line Seyfert 1 galaxy PG 1402+261. The EPIC X-ray spectrum of PG 1402+261 shows a strong excess of counts between 6 and 9 keV in the rest frame. This feature can be modeled by an unusually strong (equivalent width 2 keV) and very broad (FWHM velocity of 110,000 km s-1) iron K-shell emission line. The line centroid energy at 7.3 keV appears blueshifted with respect to the iron Kα emission band between 6.4 and 6.97 keV, while the blue wing of the line extends to 9 keV in the quasar rest frame. The line profile can be fitted by reflection from the inner accretion disk, but an inclination angle of >60° is required to model the extreme blue wing of the line. Furthermore, the extreme strength of the line requires a geometry whereby the hard X-ray emission from PG 1402+261 above 2 keV is dominated by the pure-reflection component from the disk, while little or none of the direct hard power law is observed. Alternatively, the spectrum above 2 keV may be explained by an ionized absorber, if the column density is sufficiently high (NH>3×1023 cm-2) and if the matter is ionized enough to produce a deep (τ~1) iron K-shell absorption edge at 9 keV. This absorber could originate in a large column density, high-velocity outflow, perhaps similar to those that appear to be observed in several other high accretion rate active galactic nuclei. Further observations, especially at higher spectral resolution, are required to distinguish between the accretion disk reflection and outflow scenarios.
Luciano, Rezzolla
2013-01-01
Relativistic hydrodynamics is a very successful theoretical framework to describe the dynamics of matter from scales as small as those of colliding elementary particles, up to the largest scales in the universe. This book provides an up-to-date, lively, and approachable introduction to the mathematical formalism, numerical techniques, and applications of relativistic hydrodynamics. The topic is typically covered either by very formal or by very phenomenological books, but is instead presented here in a form that will be appreciated both by students and researchers in the field. The topics covered in the book are the results of work carried out over the last 40 years, which can be found in rather technical research articles with dissimilar notations and styles. The book is not just a collection of scattered information, but a well-organized description of relativistic hydrodynamics, from the basic principles of statistical kinetic theory, down to the technical aspects of numerical methods devised for the solut...
Hansen, S. B.; Harding, E. C.; Knapp, P. F.; Gomez, M. R.; Nagayama, T.; Bailey, J. E.
2017-09-01
We present high-resolution spectroscopic data from iron impurities in beryllium liners driven by Sandia's Z machine to temperatures near 10 eV and electron densities near 2 × 1024 cm-3, conditions independently diagnosed from the transmission depth and shape of the iron K-edge. A 12-eV redshift is observed in the Fe Kβ fluorescence line along with few-eV shifts in the Fe Kα lines and Fe K-shell absorption edge. While the measured edge shift disagrees with several common models of ionization potential depression, both line and edge shifts are in good agreement with the predictions of a self-consistent model based on density functional theory.
Theoretical modelling of the AGN iron line vs. continuum time-lags in the lamp-post geometry
Epitropakis, A.; Papadakis, I. E.; Dovčiak, M.; Pecháček, T.; Emmanoulopoulos, D.; Karas, V.; McHardy, I. M.
2016-10-01
Context. Theoretical modelling of time-lags between variations in the Fe Kα emission and the X-ray continuum might shed light on the physics and geometry of the X-ray emitting region in active galaxies (AGN) and X-ray binaries. We here present the results from a systematic analysis of time-lags between variations in two energy bands (5-7 vs. 2-4 keV) for seven X-ray bright and variable AGN. Aims: We estimate time-lags as accurately as possible and fit them with theoretical models in the context of the lamp-post geometry. We also constrain the geometry of the X-ray emitting region in AGN. Methods: We used all available archival XMM-Newton data for the sources in our sample and extracted light curves in the 5-7 and 2-4 keV energy bands. We used these light curves and applied a thoroughly tested (through extensive numerical simulations) recipe to estimate time-lags that have minimal bias, approximately follow a Gaussian distribution, and have known errors. Using traditional χ2 minimisation techniques, we then fitted the observed time-lags with two different models: a phenomenological model where the time-lags have a power-law dependence on frequency, and a physical model, using the reverberation time-lags expected in the lamp-post geometry. The latter were computed assuming a point-like primary X-ray source above a black hole surrounded by a neutral and prograde accretion disc with solar iron abundance. We took all relativistic effects into account for various X-ray source heights, inclination angles, and black hole spin values. Results: Given the available data, time-lags between the two energy bands can only be reliably measured at frequencies between ~5 × 10-5 Hz and ~10-3 Hz. The power-law and reverberation time-lag models can both fit the data well in terms of formal statistical characteristics. When fitting the observed time-lags to the lamp-post reverberation scenario, we can only constrain the height of the X-ray source. The data require, or are consistent
Haba, Z
2009-02-01
We discuss relativistic diffusion in proper time in the approach of Schay (Ph.D. thesis, Princeton University, Princeton, NJ, 1961) and Dudley [Ark. Mat. 6, 241 (1965)]. We derive (Langevin) stochastic differential equations in various coordinates. We show that in some coordinates the stochastic differential equations become linear. We obtain momentum probability distribution in an explicit form. We discuss a relativistic particle diffusing in an external electromagnetic field. We solve the Langevin equations in the case of parallel electric and magnetic fields. We derive a kinetic equation for the evolution of the probability distribution. We discuss drag terms leading to an equilibrium distribution. The relativistic analog of the Ornstein-Uhlenbeck process is not unique. We show that if the drag comes from a diffusion approximation to the master equation then its form is strongly restricted. The drag leading to the Tsallis equilibrium distribution satisfies this restriction whereas the one of the Jüttner distribution does not. We show that any function of the relativistic energy can be the equilibrium distribution for a particle in a static electric field. A preliminary study of the time evolution with friction is presented. It is shown that the problem is equivalent to quantum mechanics of a particle moving on a hyperboloid with a potential determined by the drag. A relation to diffusions appearing in heavy ion collisions is briefly discussed.
Sahoo, Raghunath
2016-01-01
This lecture note covers Relativistic Kinematics, which is very useful for the beginners in the field of high-energy physics. A very practical approach has been taken, which answers "why and how" of the kinematics useful for students working in the related areas.
Veiga, R.G.A., E-mail: rgaveiga@gmail.com [Universite de Lyon, INSA Lyon, Laboratoire MATEIS, UMR CNRS 5510, 25 Avenue Jean Capelle, F69621, Villeurbanne (France); Perez, M. [Universite de Lyon, INSA Lyon, Laboratoire MATEIS, UMR CNRS 5510, 25 Avenue Jean Capelle, F69621, Villeurbanne (France); Becquart, C.S. [Unite Materiaux et Transformations (UMET), Ecole Nationale Superieure de Chimie de Lille, UMR CNRS 8207, Bat. C6, F59655 Villeneuve d' Ascq Cedex (France); Laboratoire commun EDF-CNRS Etude et Modelisation des Microstructures pour le Vieillissement des Materiaux (EM2VM) (France); Clouet, E. [Service de Recherches de Metallurgie Physique, CEA/Saclay, 91191 Gif-sur-Yvette (France); Domain, C. [EDF, Recherche et Developpement, Materiaux et Mecanique des Composants, Les Renardieres, F77250 Moret sur Loing (France); Laboratoire commun EDF-CNRS Etude et Modelisation des Microstructures pour le Vieillissement des Materiaux (EM2VM) (France)
2011-10-15
Energy barriers for carbon migration in the neighborhood of line defects in body-centered cubic iron have been obtained by atomistic simulations. For this purpose, molecular statics with an Fe-C interatomic potential, based on the embedded atom method, has been employed. Results of these simulations have been compared to the predictions of anisotropic elasticity theory. The agreement is better for a carbon atom sitting on an octahedral site (energy minimum) than one on a tetrahedral site (saddle point). Absolute differences in the energy barriers obtained by the two methods are usually below 5 meV at distances larger than 1.5 nm from a screw dislocation and 2 nm (up to 4 nm in the glide plane) from the edge dislocation. Atomistic kinetic Monte Carlo simulations performed at T = 300 K and additional analysis based on the activation energies obtained by both methods show that they are in good qualitative agreement, despite some important quantitative discrepancies due to the large absolute errors found near the dislocation cores.
Strong Variability of Overlapping Iron Broad Absorption Lines in five Radio-selected Quasars
Zhang, Shaohua; Wang, Tinggui; Wang, Huiyuan; Shi, Xiheng; Liu, Bo; Liu, Wenjuan; Li, Zhenzhen; Wang, Shufen
2015-01-01
We present the results of a variability study of broad absorption lines (BALs) in a uniformly radio-selected sample of 28 BAL quasars using the archival data from the first bright quasar survey (FBQS) and the Sloan Digital Sky Survey (SDSS), as well as those obtained by ourselves, covering time scales $\\sim 1-10$ years in the quasar's rest-frame. The variable absorption troughs are detected in 12 BAL quasars. Among them, five cases showed strong spectral variations and are all belong to a special subclass of overlapping iron low ionization BALs (OFeLoBALs). The absorbers of \\ion{Fe}{2} are estimated to be formed by a relative dense (\\mbox{$n\\rm _{e} > 10^6~cm^{-3}$}) gas at a distance from the subparsec scale to the dozens of parsec-scale from the continuum source. They differ from those of invariable non-overlapping FeLoBALs (non-OFeLoBALs), which are the low-density gas and locate at the distance of hundreds to thousands parsecs. OFeLoBALs and non-OFeLoBALs, i.e., FeLoBALs with/without strong BAL variations...
Iron K α line of Kerr black holes with Proca hair
Zhou, Menglei; Bambi, Cosimo; Herdeiro, Carlos A. R.; Radu, Eugen
2017-05-01
We continue our study on the capabilities of present and future x-ray missions to test the nature of astrophysical black hole candidates via x-ray reflection spectroscopy and distinguish Kerr black holes from other solutions of 4-dimensional Einstein's gravity in the presence of a matter field. Here we investigate the case of Kerr black holes with Proca hair [1]. The analysis of a sample of these configurations suggests that even extremely hairy black holes can mimic the iron line profile of the standard Kerr black holes, and, at least for the configurations of our study, we find that current x-ray missions cannot distinguish these objects from Kerr black holes. This contrasts with our previous findings for the case of Kerr black holes with scalar (rather than Proca) hair [2], even though such comparison may be biased by the limited sample. Future x-ray missions can detect the presence of Proca hair, but a theoretical knowledge of the expected intensity profile (currently missing) can be crucial to obtain strong constraints.
Iron K$\\alpha$ line of Kerr black holes with scalar hair
Ni, Yueying; Cardenas-Avendano, Alejandro; Bambi, Cosimo; Herdeiro, Carlos A R; Radu, Eugen
2016-01-01
Recently, a family of hairy black holes in 4-dimensional Einstein gravity minimally coupled to a complex, massive scalar field was discovered (Herdeiro & Radu, 2014). Besides the mass $M$ and spin angular momentum $J$, these objects are characterized by a Noether charge $Q$, measuring the amount of scalar hair, which is not associated to a Gauss law and cannot be measured at spatial infinity. Introducing a dimensionless scalar hair parameter $q$, ranging from 0 to 1, we recover (a subset of) Kerr black holes for $q=0$ and a family of rotating boson stars for $q=1$. In the present paper, we explore the possibility of measuring $q$ for astrophysical black holes with current and future X-ray missions. We study the iron K$\\alpha$ line expected in the reflection spectrum of such hairy black holes and we simulate observations with Suzaku and eXTP. As a proof of concept we show, by analyzing a sample of hairy black holes, that current observations can already rule out a region in the space of solutions, because ...
Safronova, U I; Safronova, A S; Beiersdorfer, P
2007-10-08
Transition rates and line strengths are calculated for electric-multipole (E2 and E3) and magnetic-multipole (M1, M2, and M3) transitions between 3s{sup 2}3p{sup 6}3d{sup 10}, 3s{sup 2}3p{sup 6}3d{sup 9}4l, 3s{sup 2}3p{sup 5}3d{sup 10}4l, and 3s3p{sup 6}3d{sup 10}4l states (with 4l = 4s, 4p, 4d, and 4f) in Ni-like ions with the nuclear charges ranging from Z = 34 to 100. Relativistic many-body perturbation theory (RMBPT), including the Breit interaction, is used to evaluate retarded multipole matrix elements. Transition energies used in the calculation of line strengths and transition rates are from second-order RMBPT. Lifetimes of the 3s{sup 2}3p{sup 6}3d{sup 9}4s levels are given for Z = 34-100. Taking into account that calculations were performed in a very broad range of Z, most of the data are presented in graphs as Z-dependencies. The full set of data is given only for Ni-like W ion. In addition, we also give complete results for the 3d4s{sup 3}D{sub 2}-3d4s {sup 3}D{sub 1} magnetic-dipole transition, as the transition may be observed in future experiments, which measure both transition energies and radiative rates. These atomic data are important in the modeling of radiation spectra from Ni-like multiply-charged ions generated in electron beam ion trap experiments as well as for laboratory plasma diagnostics including fusion research.
On-line monitoring of particulate iron oxides in steam generator feedwater using x-ray fluorescence
Stauffer, C.C.; Connolly, D.J. [Babcock and Wilcox, Alliance, OH (United States). Research and Development Division; Millett, P.J. [Electric Power Research Inst., Palo Alto, CA (United States)
1995-12-01
Corrosion product monitoring is important as power plants strive to minimize corrosion and maximize availability. Current methodology for monitoring corrosion products involves grab sampling and/or collection of integrated samples using membrane filters followed by analysis of the membranes in the laboratory. This technique is labor intensive and provides only average values over lengthy sampling intervals (typically 1--3 days). Recently, a laboratory tool -- x-ray fluorescence (XRF) spectroscopy -- was combined with existing on-line sampling techniques resulting in an on-line XRF monitor capable of measuring iron oxide particulates in a flowing stream at the parts-per-billion (ppb) level and below. After development in the laboratory, the instrument was successfully field tested in two power plants. After testing at the first power plant, modifications to improve instrument performance were incorporated. This paper presents information regarding design and operation of the instrument, improvements made during the first test period, and field data obtained during plant service. Results show that this instrument will provide on-line measurements of iron oxides at the ppb level with minimal operator involvement. Finally, there are wider applications for this on-line XRF monitor. Though the present system is geared toward iron analysis in corrosion products, it could as well be configured for other elements or groups of elements for other applications such lead, sulfur, copper, chromium, or any other element detectable by x-ray fluorescence.
Experimental analysis of flow of ductile cast iron in stream lined gating systems
Skov-Hansen, Søren; Green, Nick; Tiedje, Niels Skat
2008-01-01
Streamlined gating systems have been developed for production of high integrity ductile cast iron parts. Flow of ductile cast iron in streamlined gating systems was studied in glass fronted sand moulds where flow in the gating system and casting was recorded by a digital video camera. These resul...
Suzaku discovery of iron absorption lines in outburst spectra of the X-ray transient 4U 1630-472
Kubota, A; Cottam, J; Kotani, T; Done, C; Ueda, Y; Fabian, A C; Yasuda, T; Takahashi, H; Fukazawa, Y; Yamaoka, K; Makishima, K; Yamada, S; Kohmura, T; Angelini, L; Kubota, Aya; Dotani, Tadayasu; Cottam, Jean; Kotani, Taro; Done, Chris; Ueda, Yoshihiro; Fabian, Andrew C.; Yasuda, Tomonori; Takahashi, Hiromitsu; Fukazawa, Yasushi; Yamaoka, Kazutaka; Makishima, Kazuo; Yamada, Shinya; Kohmura, Takayoshi; Angelini, Lorella
2006-01-01
We present the results of six Suzaku observations of the recurrent black hole transient 4U1630-472 during its decline from outburst from February 8 to March 23 in 2006. All observations show the typical high/soft state spectral shape in the 2-50keV band, roughly described by an optically thick disk spectrum in the soft energy band plus a weak power-law tail that becomes dominant only above \\~20keV. The disk temperature decreases from 1.4keV to 1.2keV as the flux decreases by a factor 2, consistent with a constant radius as expected for disk-dominated spectra. All the observations reveal significant absorption lines from highly ionized (H-like and He-like) iron Ka at 7.0keV and 6.7keV. The brightest datasets also show significant but weaker absorption structures between 7.8keV and 8.2keV, which we identify as a blend of iron Kb and nickel Ka absorption lines. The energies of these absorption lines suggest a blue shift with an outflow velocity of ~1000km/s.. The H-like iron Ka equivalent width remains approxima...
Hakim, Rémi
1994-01-01
Il existe à l'heure actuelle un certain nombre de théories relativistes de la gravitation compatibles avec l'expérience et l'observation. Toutefois, la relativité générale d'Einstein fut historiquement la première à fournir des résultats théoriques corrects en accord précis avec les faits.
Jones, Bernard J. T.; Markovic, Dragoljub
1997-06-01
Preface; Prologue: Conference overview Bernard Carr; Part I. The Universe At Large and Very Large Redshifts: 2. The size and age of the Universe Gustav A. Tammann; 3. Active galaxies at large redshifts Malcolm S. Longair; 4. Observational cosmology with the cosmic microwave background George F. Smoot; 5. Future prospects in measuring the CMB power spectrum Philip M. Lubin; 6. Inflationary cosmology Michael S. Turner; 7. The signature of the Universe Bernard J. T. Jones; 8. Theory of large-scale structure Sergei F. Shandarin; 9. The origin of matter in the universe Lev A. Kofman; 10. New guises for cold-dark matter suspects Edward W. Kolb; Part II. Physics and Astrophysics Of Relativistic Compact Objects: 11. On the unification of gravitational and inertial forces Donald Lynden-Bell; 12. Internal structure of astrophysical black holes Werner Israel; 13. Black hole entropy: external facade and internal reality Valery Frolov; 14. Accretion disks around black holes Marek A. Abramowicz; 15. Black hole X-ray transients J. Craig Wheeler; 16. X-rays and gamma rays from active galactic nuclei Roland Svensson; 17. Gamma-ray bursts: a challenge to relativistic astrophysics Martin Rees; 18. Probing black holes and other exotic objects with gravitational waves Kip Thorne; Epilogue: the past and future of relativistic astrophysics Igor D. Novikov; I. D. Novikov's scientific papers and books.
Microarray analysis of iron deficiency chlorosis in near-isogenic soybean lines
Cianzio Silvia R; Graham Michelle A; Vodkin Lila O; Gonzalez Delkin O; Charlson Dirk V; O'Rourke Jamie A; Grusak Michael A; Shoemaker Randy C
2007-01-01
Abstract Background Iron is one of fourteen mineral elements required for proper plant growth and development of soybean (Glycine max L. Merr.). Soybeans grown on calcareous soils, which are prevalent in the upper Midwest of the United States, often exhibit symptoms indicative of iron deficiency chlorosis (IDC). Yield loss has a positive linear correlation with increasing severity of chlorotic symptoms. As soybean is an important agronomic crop, it is essential to understand the genetics and ...
Sivakumar, P.; Taleh, L.; Markushin, Y. [Optical Science Center for Applied Research and Applications, Department of Physics and Pre-Engineering, Delaware State University, Dover, DE 19901 (United States); Melikechi, N., E-mail: nmelikechi@desu.edu [Optical Science Center for Applied Research and Applications, Department of Physics and Pre-Engineering, Delaware State University, Dover, DE 19901 (United States); Lasue, J. [Université de Toulouse, UPS-OMP, IRAP, 9 Av. Colonel Roche, BP 44346, F-31028 Toulouse Cedex 4 (France); ISR, MS D466, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Lunar and Planetary Institute, 3600 Bay Area Boulevard, Houston, TX 77058 (United States)
2013-04-01
We report on the dependence of the intensities of atomic and ionic lines emitted by a nanosecond laser-induced plasma on the atomic number densities of the constituents of a binary mixture formed of carbon and iron. We show that the packing density of the sample greatly affects the relative standard deviation of the emission lines. Furthermore, we show that the variation of the intensities of the C and Fe emission lines depends in a non-trivial way on the relative C–Fe concentration. The intensities of Fe neutral atomic lines behave differently than those of the ionic ones particularly at and above concentrations of 75%–80% Fe embedded in a carbon matrix. Unlike the emission from neutral Fe, those from ionic Fe yield a very sharp decrease followed by an equally strong increase of the emission lines over a relatively small range of relative concentration of C and Fe. To better investigate this effect, we have compared the results obtained with nanosecond-LIBS to those with femtosecond-LIBS and found that this phenomenon disappears. The physical interpretation of the sharp decrease followed by an equally sharp increase in the emission intensities from Fe ions as the concentration of Fe is increased requires more studies. - Highlights: ► The effects of the size of the particles on the fluctuations of the LIBS signals ► The variation of LIBS signals with the concentrations of Fe embedded in C is nontrivial. ► The intensities of neutral atomic lines can behave differently than those of ions.
NSGIC GIS Inventory (aka Ramona) — This Transmission Lines or Poles, Electric dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2005. It is...
Relativistic and non-relativistic geodesic equations
Giambo' , R.; Mangiarotti, L.; Sardanashvily, G. [Camerino Univ., Camerino, MC (Italy). Dipt. di Matematica e Fisica
1999-07-01
It is shown that any dynamic equation on a configuration space of non-relativistic time-dependent mechanics is associated with connections on its tangent bundle. As a consequence, every non-relativistic dynamic equation can be seen as a geodesic equation with respect to a (non-linear) connection on this tangent bundle. Using this fact, the relationships between relativistic and non-relativistic equations of motion is studied.
Mondal, Aditya S.; Dewangan, G. C.; Pahari, M.; Misra, R.; Kembhavi, A. K.; Raychaudhuri, B.
2016-09-01
Broad relativistic iron lines from neutron star X-ray binaries are important probes of the inner accretion disc. The X-ray reflection features can be weakened due to strong magnetic fields or very low iron abundances such as is possible in X-ray binaries with low mass, first generation stars as companions. Here, we investigate the reality of the broad iron line detected earlier from the neutron-star low-mass X-ray binary 4U 1820-30 with a degenerate helium dwarf companion. We perform a comprehensive, systematic broad-band spectral study of the atoll source using Suzaku and simultaneous NuSTAR and Swift observations. We have used different continuum models involving accretion disc emission, thermal blackbody and thermal Comptonization of either disc or blackbody photons. The Suzaku data show positive and negative residuals in the region of Fe K band. These features are well described by two absorption edges at 7.67 ± 0.14 keV and 6.93 ± 0.07 keV or partial covering photoionized absorption or by blurred reflection. Though, the simultaneous Swift and NuSTAR data do not clearly reveal the emission or absorption features, the data are consistent with the presence of either absorption or emission features. Thus, the absorption based models provide an alternative to the broad iron line or reflection model. The absorption features may arise in winds from the inner accretion disc. The broad-band spectra appear to disfavour continuum models in which the blackbody emission from the neutron-star surface provides the seed photons for thermal Comptonization. Our results suggest emission from a thin accretion disc (kTdisc ˜ 1 keV), Comptonization of disc photons in a boundary layer most likely covering a large fraction of the neutron-star surface and innermost parts of the accretion disc, and blackbody emission (kTbb ˜ 2 keV) from the polar regions.
Cackett, E M; Homan, J; Van der Klis, M; Lewin, W H G; Méndez, M; Raymond, J; Steeghs, D; Wijnands, R
2008-01-01
While iron emission lines are well studied in black hole systems, both in X-ray binaries and Active Galactic Nuclei, there has been less of a focus on these lines in neutron star low-mass X-ray binaries (LMXBs). However, recent observations with Suzaku and XMM-Newton have revealed broad asymmetric iron line profiles in 4 neutron star LMXBs, confirming an inner disk origin for these lines in neutron star systems. Here, we present a search for iron lines in 6 neutron star LMXBs. For each object we have simultaneous Chandra and RXTE observations at 2 separate epochs, allowing for both a high resolution spectrum, as well as broadband spectral coverage. Out of the six objects in the survey, we only find significant iron lines in two of the objects, GX 17+2 and GX 349+2. However, we cannot rule out that there are weak, broad lines present in the other sources. The equivalent width of the line in GX 17+2 is consistent between the 2 epochs, while in GX 349+2 the line equivalent width increases by a factor of ~3 betwe...
Hiemstra, Beike; Done, Chris; Trigo, Maria Diaz; Altamirano, Diego; Casella, Piergiorgio
2010-01-01
We observed the new X-ray transient and black-hole candidate XTE J1652-453 simultaneously with XMM-Newton and the Rossi X-ray Timing Explorer (RXTE). The observation was done during the decay of the 2009 outburst, when XTE J1652-453 was in the hard-intermediate state. The spectrum shows a strong and broad iron emission line with an equivalent width of ~ 450 eV. The profile is consistent with that of a line being produced by reflection off the accretion disk, broadened by relativistic effects close to the black hole. The best-fitting inner radius of the accretion disk is ~ 4 gravitational radii. Assuming that the accretion disk is truncated at the radius of the innermost stable circular orbit, the black hole in XTE J1652-453 has a spin parameter of ~ 0.5. The power spectrum of the RXTE observation has an additional variability component above 50 Hz, which is typical for the hard-intermediate state. No coherent quasi-periodic oscillations at low frequency are apparent in the power spectrum, which may imply that...
Idris, Nasrullah; Lahna, Kurnia; Fadhli; Ramli, Muliadi
2017-05-01
In this work, LIBS technique has been used for detection of heavy metal especially iron, Fe in soil sample. As there are a large number of emission spectral lines due to Fe and other constituents in soil, this study is intended to identify emission spectral lines of Fe and finally to find best fit emission spectral lines for carrying out a qualitative and quantitative analysis. LIBS apparatus used in this work consists of a laser system (Neodymium Yttrium Aluminum Garnet, Nd-YAG: Quanta Ray; LAB SERIES; 1,064 nm; 500 mJ; 8 ns) and an optical multichannel analyzer (OMA) system consisting of a spectrograph (McPherson model 2061; 1,000 mm focal length; f/8.6 Czerny- Turner) and an intensified charge coupled device (ICCD) 1024x256 pixels (Andor I*Star). The soil sample was collected from Banda Aceh city, Aceh, Indonesia. For spectral data acquisition, the soil sample has been prepared by a pressing machine in the form of pellet. The laser beam was focused using a high density lens (f=+150 mm) and irradiated on the surface of the pellet for generating luminous plasma under 1 atmosphere of air surrounding. The plasma emission was collected by an optical fiber and then sent to the optical multichannel analyzer (OMA) system for acquisition of the emission spectra. It was found that there are many Fe emission lines both atomic lines (Fe I) and ionic lines (Fe II) appeared in all detection windows in the wavelength regions, ranging from 200 nm to 1000 nm. The emission lines of Fe with strong intensities occurs together with emission lines due to other atoms such as Mg, Ca, and Si. Thus, the identification of emission lines from Fe is complicated by presence of many other lines due to other major and minor elements in soil. Considering the features of the detected emission lines, several emission spectral lines of Fe I (atomic emission line), especially Fe I 404.58 nm occurring at visible range are potential to be good candidate of analytical lines in relation to detection
Duro, Refiz; Grinberg, Victoria; Miškovičová, Ivica; Rodriguez, Jérôme; Tomsick, John; Hanke, Manfred; Pottschmidt, Katja; Nowak, Michael A; Kreykenbohm, Sonja; Bel, Marion Cadolle; Bodaghee, Arash; Lohfink, Anne; Kendziorra, Eckhard; Kirsch, Marcus G F; Staubert, Rüdiger; Wilms, Jörn
2016-01-01
We report on the analysis of the broad Fe Kalpha line feature of Cygnus X-1 in the spectra of four simultaneous hard intermediate state observations made with the X-ray Multiple Mirror mission (XMM-Newton), the Rossi X-ray Timing Explorer (RXTE), and the International Gamma-Ray Astrophysics Laboratory (INTEGRAL). The high quality of the XMM-Newton data taken in the Modified Timing Mode of the EPIC-pn camera provides a great opportunity to investigate the broadened Fe Kalpha reflection line at 6.4keV with a very high signal to noise ratio. The 4-500keV energy range is used to constrain the underlying continuum and the reflection at higher energies. We first investigate the data by applying a phenomenological model that consists of the sum of an exponentially cutoff power law and relativistically smeared reflection. Additionally, we apply a more physical approach and model the irradiation of the accretion disk directly from the lamp post geometry. All four observations show consistent values for the black hole ...
Duro, Refiz; Dauser, Thomas; Grinberg, Victoria; Miškovičová, Ivica; Rodriguez, Jérôme; Tomsick, John; Hanke, Manfred; Pottschmidt, Katja; Nowak, Michael A.; Kreykenbohm, Sonja; Cadolle Bel, Marion; Bodaghee, Arash; Lohfink, Anne; Reynolds, Christopher S.; Kendziorra, Eckhard; Kirsch, Marcus G. F.; Staubert, Rüdiger; Wilms, Jörn
2016-05-01
We report on the analysis of the broad Fe Kα line feature of Cyg X-1 in the spectra of four simultaneous hard intermediate state observations made with the X-ray Multiple Mirror mission (XMM-Newton), the Rossi X-ray Timing Explorer (RXTE), and the International Gamma-Ray Astrophysics Laboratory (INTEGRAL). The high quality of the XMM-Newton data taken in the Modified Timing Mode of the EPIC-pn camera provides a great opportunity to investigate the broadened Fe Kα reflection line at 6.4 keV with a very high signal to noise ratio. The 4-500 keV energy range is used to constrain the underlying continuum and the reflection at higher energies. We first investigate the data by applying a phenomenological model that consists of the sum of an exponentially cutoff power law and relativistically smeared reflection. Additionally, we apply a more physical approach and model the irradiation of the accretion disk directly from the lamp post geometry. All four observations show consistent values for the black hole parameters with a spin of a ~ 0.9, in agreement with recent measurements from reflection and disk continuum fitting. The inclination is found to be i ~ 30°, consistent with the orbital inclination and different from inclination measurements made during the soft state, which show a higher inclination. We speculate that the difference between the inclination measurements is due to changes in the inner region of the accretion disk.
Relativistic magnetohydrodynamics
Hernandez, Juan; Kovtun, Pavel
2017-05-01
We present the equations of relativistic hydrodynamics coupled to dynamical electromagnetic fields, including the effects of polarization, electric fields, and the derivative expansion. We enumerate the transport coefficients at leading order in derivatives, including electrical conductivities, viscosities, and thermodynamic coefficients. We find the constraints on transport coefficients due to the positivity of entropy production, and derive the corresponding Kubo formulas. For the neutral state in a magnetic field, small fluctuations include Alfvén waves, magnetosonic waves, and the dissipative modes. For the state with a non-zero dynamical charge density in a magnetic field, plasma oscillations gap out all propagating modes, except for Alfvén-like waves with a quadratic dispersion relation. We relate the transport coefficients in the "conventional" magnetohydrodynamics (formulated using Maxwell's equations in matter) to those in the "dual" version of magnetohydrodynamics (formulated using the conserved magnetic flux).
Leardini, Fabrice
2013-01-01
This manuscript presents a problem on special relativity theory (SRT) which embodies an apparent paradox relying on the concept of simultaneity. The problem is represented in the framework of Greek epic poetry and structured in a didactic way. Owing to the characteristic properties of Lorenz transformations, three events which are simultaneous in a given inertial reference system, occur at different times in the other two reference frames. In contrast to the famous twin paradox, in the present case there are three, not two, different inertial observers. This feature provides a better framework to expose some of the main characteristics of SRT, in particular, the concept of velocity and the relativistic rule of addition of velocities.
马振国
2002-01-01
Fe Kα lines are superimposed upon the x-ray continuum in most Seyfert(-like) active galactic nuclei (AGNs).By a data-fitting study, previous authors have claimed that the central black hole (BH) is either rotating ornon-rotating according to the thin disc model. We develop the disc model to the torus model to determine thereal spin of the BH. With formulations of the motion of both torus particles and photons near a BH in Kerrmetric, we simulate iron emission linesfrom a thin luminous torus. It is found that only spinning BH galaxiescan radiate observable profiles. The data-fitting to Fe lines of four AGNs observed by ASCA predicts that thecentral BH is spinning rapidly with the dimensionless specific angular momentum approaching the maximalvalueof 1.
BeppoSAX observations of Narrow-Line Seyfert 1 galaxies II. Ionized iron features in Arakelian 564
Comastri, A; Vignali, C; Brandt, W N; Leighly, K M; Fiore, F; Guainazzi, M; Matt, G; Nicastro, F; Puchnarewicz, E M; Siemiginowska, A L
2000-01-01
The BeppoSAX observations of the bright Narrow-Line Seyfert 1 galaxy Ark 564 are presented along with a high quality optical spectrum taken at the 1.5m telescope at La Silla. The 0.1-10 keV X-ray spectrum is characterized by a strong soft component which is best described by blackbody-like emission with a temperature of about 160 eV. At higher energies a steep (Gamma = 2.4) power-law tail is present. There is evidence of an ionized reflector in the form of an iron line and edge. We do not find significant evidence of soft X-ray features if the spectrum is modelled with a two component continuum. The optical and X-ray spectral properties support the hypothesis of a high accretion rate onto a low mass black hole.
Kolehmainen, M; Trigo, M Diaz
2013-01-01
The inner radius of the accretion disc around a black hole in the low/hard state can be measured in one of two ways. Firstly, via the extent of broadening of the iron emission line, and secondly, from the luminosity and temperature of the weak soft component seen in this state, assuming it is the disc. We use both of these methods on all the low/hard state spectra taken in timing mode of XMM-Newton's EPIC-pn. We find that the two methods are not consistent with each other, and the difference is not always in a single direction. The two methods are neither model independent, nor are they independent of current calibration issues. We find that the remaining small residuals in the EPIC-pn timing mode response at the <3% level can have a dramatic effect on the fit parameters for the reflected spectrum. There is also a mismatch in cross-calibration with RXTE, which makes it difficult to use simultaneous data to extend the bandpass of the spectral fits. Nonetheless, it is clear from the data that the iron line i...
Sanna, Andrea; Altamirano, Diego; Belloni, Tomaso; Hiemstra, Beike; Linares, Manuel
2014-01-01
Both the broad iron (Fe) line and the frequency of the kilohertz quasi-periodic oscillations (kHz QPOs) in neutron star low-mass X-ray binaries (LMXBs) can potentially provide independent measures of the inner radius of the accretion disc. We use XMM-Newton and simultaneous Rossi X-ray Timing Explorer observations of the LMXB 4U 1636-53 to test this hypothesis. We study the properties of the Fe-K emission line as a function of the spectral state of the source and the frequency of the kHz QPOs. We find that the inner radius of the accretion disc deduced from the frequency of the upper kHz QPO varies as a function of the position of the source in the colour-colour diagram, in accordance with previous work and with the standard scenario of accretion disc geometry. On the contrary, the inner disc radius deduced from the profile of the Fe line is not correlated with the spectral state of the source. The values of the inner radius inferred from kHz QPOs and Fe lines, in four observations, do not lead to a consisten...
Investigation of Bond Strength in Centrifugal Lining of Babbitt on Cast Iron
Diouf, Papa; Jones, Alan
2010-03-01
The quality of the bond between Babbitt metal and a cast iron substrate was evaluated for centrifugal casting and static casting using the Chalmers bond strength method and scanning electron microscopy (SEM). The effect of three different centrifugal casting parameters, the speed of revolution, the pouring rate, and the cooling rate, was investigated. The bond strength and the microstructure at the bond interface were predominantly affected by the cooling rate, with a fast cooling rate resulting in better properties. The speed of revolution and the pouring rate only had a small effect on the bond strength, with faster revolution and faster pouring rate resulting in slightly better bonds.
Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line
Cheng, X.; Ding, M. D.
2016-05-01
In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s-1 and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (˜11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.
The iron $K_\\alpha$ lines as a tool for magnetic field estimations in non-flat accretion flows
Zakharov, A F; Bao, Y
2004-01-01
Observations of AGNs and microquasars by ASCA, RXTE, Chandra and XMM-Newton indicate the existence of broad X-ray emission lines of ionized heavy elements in their spectra. Such spectral lines were discovered also in X-ray spectra of neutron stars and X-ray afterglows of GRBs. Recently, Zakharov et al. (MNRAS, 2003, 342, 1325) described a procedure to estimate an upper limit of the magnetic fields in regions from which X-ray photons are emitted. The authors simulated typical profiles of the iron $K_\\alpha$ line in the presence of magnetic field and compared them with observational data in the framework of the widely accepted accretion disk model. Here we further consider typical Zeeman splitting in the framework of a model of non-flat accretion flows, which is a generalization of previous consideration into non-equatorial plane motion of particles emitting X-ray photons. Using perspective facilities of space borne instruments (e.g. Constellation-X mission) a better resolution of the blue peak structure of iro...
X-ray bumps, iron K-alpha lines, and X-ray suppression by obscuring tori in Seyfert galaxies
Krolik, Julian H.; Madau, Piero; Zycki, Piotr T.
1994-01-01
We investigate the X-ray spectral properties of unobscured type 1 and obscured type 2 Seyferts as predicted by the unified Seyfert scheme. We consider the reprocessing of X-ray photons by photoelectric absorption, iron fluorescence, and Compton downscattering in the obscuring tori surrounding these active nuclei, and compute by Monte Carlo methods the reprocessed spectra as a function of the viewing angle. Depending on the optical depth and shape of the torus, and on the viewing angle, the X-ray flux can be suppressed by substantial factors when our line of sight is obscured. We show that an immediate consequence of the existence of an obscuring thick torus is the production in the spectra of type 1 Seyfert galaxies of a bump in the continuum above 10-20 keV and an Fe K-alpha line with significant equivalent width. In those type 2 Seyferts for which the hard X-ray spectrum has been substantially suppressed, the equivalent width of the Fe K-alpha line in the transmitted spectrum can be very large.
Variability of factors that affect availability of iron, manganese and zinc in maize lines
Dragičević Vesna
2013-01-01
Full Text Available Deficiencies of some mineral elements are causing serious health problems, which could be prevented by increase of mineral nutrients in food with supplementation, food fortification or plant breeding. From this point, experiment with 78 maize inbred lines was set up to determine maize lines with improved contents of Fe, Zn and Mn, as well as their relations with phytic acid, inorganic phosphorus and β-carotene, as factors which affect their absorption. Obtained results suggest that investigated maize lines show high variability in concentration of Fe, Mn and Zn, as well as phytic acid (which sustain availability of mineral elements and β-carotene (which enables better absorption of mineral element and minimize negative effect of phytic acid. From this point of view, group of genotypes with phytic P ≤ 3 g kg-1 was interesting. Among them, L2 and L23 are maize lines with relatively high inorganic P, Fe and Zn contents, and together with relatively low ratio between phytic and inorganic P, they could be used as a good source of P, Fe and Zn. On the other hand, L1 and L4 are also maize lines with high inorganic P, β-carotene and Mn, and favourable ratio between phytic acid and Fe and Zn, what could give them advance as source of Mn in breeding programs. The same maize lines could also be candidates with improved ability for Fe and Zn absorption, what is based on high β-carotene content. Maize line L14, with relatively high concentration of all three. [Projekat Ministarstva nauke Republike Srbije, br. TR 31068: Improving the quality of maize and soybean by conventional and molecular breeding
A study of the interaction between irradiation induced-defect and a line dislocation in bcc-iron
Fujita, Satoshi [Department of Quantum Engineering and Systems Science, Graduate School of Engineering, The University of Tokyo, Tokyo (Japan)], E-mail: fujita@n.t.u-tokyo.ac.jp; Okita, Taira; Kuramoto, Eiichi; Sekimura, Naoto [Department of Nuclear Engineering and Management, Graduate School of Engineering, The University of Tokyo, Tokyo (Japan)
2009-04-30
We evaluate the interaction between a line edge dislocation and a self-interstitial atom cluster in {alpha}-iron by the molecular dynamics (MD) calculation. When the distance between the slip plane of the dislocation and the cluster centroid is more than twice as large as the cluster radius and the distance between the slip plane and the nearest part of the cluster is more than 1 nm, the results obtained by MD simulation agree well with that by the dislocation theory. The calculation temperature does not affect the stable position of the cluster near the dislocation. We discuss the difference in MD and the dislocation theory and the limitation of the infinitesimal small cluster approximation.
Bambi, Cosimo
2013-01-01
Extensions of general relativity and theories aiming at unifying gravity with the forces of the Standard Model are usually characterized by new degrees of freedom and violations of the Einstein Equivalence Principle. The search for time and/or space variations of fundamental parameters like the fine structure constant $\\alpha$ tests the assumption of Local Position Invariance. In this letter, I show that the analysis of the K$\\alpha$ iron line observed in the X-ray spectrum of black holes can probe $\\alpha$ in gravitational potentials relative to Earth of $\\Delta \\phi \\approx 0.1$. From the measurements of the black hole in Cygnus X-1 reported in the literature, one obtains $|\\Delta \\alpha / \\alpha| \\lesssim 0.01$.
X-ray illuminated accretion discs: a model for the iron line in NGC 3227
George, I.M.; Fabian, A.C. (Cambridge Univ. (UK). Inst. of Astronomy); Nandra, K. (Leicester Univ. (UK). Dept. of Physics)
1990-01-01
Substantial amounts of optically thick, 'cold' gas close to the central regions of Active Galactic Nuclei reprocess the underlying non-thermal continuum. In the X-ray band, features due to bound-free absorption, fluorescence and electron scattering, as well as thermal re-emission are imprinted on the observed spectrum. Iron K-shell features are particularly evident, and provide a strong diagnostic of the geometry and kinematics of the innermost regions of the accretion flow. Here we consider a specific geometry of the cold material, namely that of a Keplerian accretion disc illuminated by an external X-ray source. The results from Monte Carlo simulations of the composite spectrum are fitted to Ginga data from NGC 3227, a Seyfert galaxy with an established emission feature. We find that the form of the X-ray spectrum of NGC 3227 is consistent with such a model of it is viewed almost face-on. (author).
Cattaneo, Carlo
2011-01-01
This title includes: Pham Mau Quam: Problemes mathematiques en hydrodynamique relativiste; A. Lichnerowicz: Ondes de choc, ondes infinitesimales et rayons en hydrodynamique et magnetohydrodynamique relativistes; A.H. Taub: Variational principles in general relativity; J. Ehlers: General relativistic kinetic theory of gases; K. Marathe: Abstract Minkowski spaces as fibre bundles; and, G. Boillat: Sur la propagation de la chaleur en relativite.
Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line
Cheng, X
2016-01-01
In this Letter, we present Interface Region Imaging Spectrograph Fe XXI 1354.08 A forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of $\\ge$1000 km s$^{-1}$ and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The EUV images at the 131 A and 94 A passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe XXI 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe XXI forbidden line requires a critical temperature ($\\sim$11.5 MK) and dens...
Departure of high temperature iron lines from the equilibrium state in flaring solar plasmas
Kawate, Tomoko; Jess, David B
2016-01-01
The aim of this study is to clarify if the assumption of ionization equilibrium and a Maxwellian electron energy distribution is valid in flaring solar plasmas. We analyze the 2014 December 20 X1.8 flare, in which the \\ion{Fe}{xxi} 187~\\AA, \\ion{Fe}{xxii} 253~\\AA, \\ion{Fe}{xxiii} 263~\\AA\\ and \\ion{Fe}{xxiv} 255~\\AA\\ emission lines were simultaneously observed by the EUV Imaging Spectrometer onboard the Hinode satellite. Intensity ratios among these high temperature Fe lines are compared and departures from isothermal conditions and ionization equilibrium examined. Temperatures derived from intensity ratios involving these four lines show significant discrepancies at the flare footpoints in the impulsive phase, and at the looptop in the gradual phase. Among these, the temperature derived from the \\ion{Fe}{xxii}/\\ion{Fe}{xxiv} intensity ratio is the lowest, which cannot be explained if we assume a Maxwellian electron distribution and ionization equilibrium, even in the case of a multi-thermal structure. This re...
Relativistic radiative transfer in relativistic spherical flows
Fukue, Jun
2017-02-01
Relativistic radiative transfer in relativistic spherical flows is numerically examined under the fully special relativistic treatment. We first derive relativistic formal solutions for the relativistic radiative transfer equation in relativistic spherical flows. We then iteratively solve the relativistic radiative transfer equation, using an impact parameter method/tangent ray method, and obtain specific intensities in the inertial and comoving frames, as well as moment quantities, and the Eddington factor. We consider several cases; a scattering wind with a luminous central core, an isothermal wind without a core, a scattering accretion on to a luminous core, and an adiabatic accretion on to a dark core. In the typical wind case with a luminous core, the emergent intensity is enhanced at the center due to the Doppler boost, while it reduces at the outskirts due to the transverse Doppler effect. In contrast to the plane-parallel case, the behavior of the Eddington factor is rather complicated in each case, since the Eddington factor depends on the optical depth, the flow velocity, and other parameters.
Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line
Cheng, X; Ding, M. D.
2016-01-01
In this Letter, we present Interface Region Imaging Spectrograph Fe XXI 1354.08 A forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of $\\ge$1000 km s$^{-1}$ and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The EUV images at the 131 A and 94 A passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot c...
A focussing iron line crystal spectrometer for Spacelab. [cosmic X-ray detection
Catura, R. C.; Culhane, J. L.; Rapley, C. G.; Gabriel, A. H.; Walker, A. B. C., Jr.; Woodgate, B. E.
1977-01-01
A crystal spectrometer system is described which employs conical focusing of 12 curved LiF crystal panels to minimize the detector size and reduce the background counting rate. The wavelength range from 1.70 to 1.98 A is covered, including the resonance lines of Fe XXV and Fe XXVI as well as the Fe I K-alpha line and absorption edge. Operation of the spectrometer is discussed, noting that diffracted X-rays are registered in one-dimensional position-sensitive detectors and that the arrival position of a photon in a detector is related to its wavelength due to the fixed curvature of the crystal panels in the dispersion plane. Some characteristics of the multianode position-sensitive detectors are reviewed along with the crystal arrangement and mounting. The instrument sensitivity is evaluated in relation to the strengths of 6.7-keV emission features detected by the Ariel 5 and OSO 8 proportional-counter spectrometers.
Relativistic Flows at the Hotspots of Radio Galaxies and Quasars?
Georganopoulos, M; Georganopoulos, Markos; Kazanas, Demosthenes
2003-01-01
We review the broad band properties of X-ray detected hotspots in radio galaxies and quasars. We show that their collective properties can be unified in a framework involving frequency dependent relativistic beaming and varying orientations to the observer's line of sight. The simplest dynamic model consistent with this picture is a slowing-down relativistic flow downstream from the hotspot shock, suggesting that the jet flow remains relativistic to the hotspot distances.
Energy spectra in relativistic electron precipitation events.
Rosenberg, T. J.; Lanzerotti, L. J.; Bailey, D. K.; Pierson, J. D.
1972-01-01
Two events in August 1967, categorized as relativistic electron precipitation (REP) events by their effect on VHF transmissions propagated via the forward-scatter mode, have been examined with regard to the energy spectra of trapped and precipitated electrons. These two substorm-associated events August 11 and August 25 differ with respect to the relativistic, trapped electron population at synchronous altitude; in the August 25 event there was a nonadiabatic enhancement of relativistic (greater than 400 keV) electrons, while in the August 11 event no relativistic electrons were produced. In both events electron spectra deduced from bremsstrahlung measurements (made on a field line close to that of the satellite) had approximately the same e-folding energies as the trapped electron enhancements. However, the spectrum of electrons in the August 25 event was significantly harder than the spectrum in the event of August 11.
Relativistic Remnants of Non-Relativistic Electrons
Kashiwa, Taro
2015-01-01
Electrons obeying the Dirac equation are investigated under the non-relativistic $c \\mapsto \\infty$ limit. General solutions are given by derivatives of the relativistic invariant functions whose forms are different in the time- and the space-like region, yielding the delta function of $(ct)^2 - x^2$. This light-cone singularity does survive to show that the charge and the current density of electrons travel with the speed of light in spite of their massiveness.
Iron Features in the XMM-Newton spectrum of NGC 4151
Schurch, N J; Griffiths, R E; Ptak, A F
2002-01-01
We present a detailed analysis of the hard X-ray (>2.5 keV) EPIC spectra from the first observations of NGC 4151 made by XMM-Newton. We fit the spectra with a model consisting of a power-law continuum modified by line-of-sight absorption (arising in both partially photoionized and neutral gas) plus additional iron-K emission and absorption features. This model provides an excellent overall fit to the EPIC spectra. The iron K-alpha line is well modelled as a narrow Gaussian component. In contrast to several earlier studies based on data from ASCA, a relativistically broadened iron K-alpha emission feature is not required by the XMM-Newton data. The upper limit on the flux contained in any additional broad line is ~8% of that in the narrow line. The measured intrinsic line width (sigma =32+_7 eV) may be ascribed to (i) the doublet nature of the iron K-alpha line and (ii) emission from low ionization states of iron, ranging from neutral up to ~FeXVII. The additional iron absorption edge arises in cool material a...
Relativistic quantum mechanics
Wachter, Armin
2010-01-01
Which problems do arise within relativistic enhancements of the Schrödinger theory, especially if one adheres to the usual one-particle interpretation, and to what extent can these problems be overcome? And what is the physical necessity of quantum field theories? In many books, answers to these fundamental questions are given highly insufficiently by treating the relativistic quantum mechanical one-particle concept very superficially and instead introducing field quantization as soon as possible. By contrast, this monograph emphasizes relativistic quantum mechanics in the narrow sense: it extensively discusses relativistic one-particle concepts and reveals their problems and limitations, therefore motivating the necessity of quantized fields in a physically comprehensible way. The first chapters contain a detailed presentation and comparison of the Klein-Gordon and Dirac theory, always in view of the non-relativistic theory. In the third chapter, we consider relativistic scattering processes and develop the...
Investigation of iron emission lines in the eclipsing high mass X-ray binary pulsar OAO 1657-415
Jaisawal, Gaurava K
2016-01-01
We present the results obtained from timing and spectral studies of high mass X-ray binary pulsar OAO 1657-415 using a Suzaku observations in 2011 September. X-ray pulsations were detected in the light curves up to $\\sim$70 keV. The continuum spectra during the high- and low-flux regions in light curves were well described by high energy cutoff power-law model along with a blackbody component and iron fluorescent lines at 6.4 keV and 7.06 keV. Time resolved spectroscopy was carried out by dividing the entire observations into 18 narrow segments. Presence of additional dense matter at various orbital phases was confirmed as the cause of low-flux regions in the observations. Presence of additional matter at several orbital phases of the pulsar was interpreted as due to the inhomogeneously distributed clumps of matter around the neutron star. Using clumpy wind hypothesis, the physical parameters of the clumps causing the high- and low-flux episodes in the pulsar light curve were estimated. The equivalent width o...
ZHANG Peng-Fei; RUAN Tu-Nan
2001-01-01
A systematic theory on the appropriate spin operators for the relativistic states is developed. For a massive relativistic particle with arbitrary nonzero spin, the spin operator should be replaced with the relativistic one, which is called in this paper as moving spin. Further the concept of moving spin is discussed in the quantum field theory. A new is constructed. It is shown that, in virtue of the two operators, problems in quantum field concerned spin can be neatly settled.
Relativistic Guiding Center Equations
White, R. B. [PPPL; Gobbin, M. [Euratom-ENEA Association
2014-10-01
In toroidal fusion devices it is relatively easy that electrons achieve relativistic velocities, so to simulate runaway electrons and other high energy phenomena a nonrelativistic guiding center formalism is not sufficient. Relativistic guiding center equations including flute mode time dependent field perturbations are derived. The same variables as used in a previous nonrelativistic guiding center code are adopted, so that a straightforward modifications of those equations can produce a relativistic version.
Relativistic Linear Restoring Force
Clark, D.; Franklin, J.; Mann, N.
2012-01-01
We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…
MALFLIET, R
1993-01-01
We discuss the present status of relativistic transport theory. Special emphasis is put on problems of topical interest: hadronic features, thermodynamical consistent approximations and spectral properties.
Barrera, Pablo M. de la; Bossio, Guillermo R.; Garcia, Guillermo O. [Grupo de Electronica Aplicada (GEA), Facultad de Ingenieria, UNRC, Ruta Nacional 36 Km. 601, X5804BYA, Rio Cuarto (Argentina); Solsona, Jorge A. [Instituto de Investigaciones en Ingenieria Electrica ' ' Alfredo Desages' ' , Departamento de Ingenieria Electrica y de Computadoras, UNS, Av. Alem 1253 (8000) Bahia Blanca (Argentina)
2008-10-15
A rotor flux state observer considering iron loss, for an Induction Motor (IM), is proposed. The aim of this proposal is to avoid detuning caused by the IM iron loss on a field-oriented control (FOC). An adaptive scheme for the K{sub Fe}, a parameter that represents the IM iron loss, is also proposed. The main objective of this scheme is to improve the dynamic response of control by compensating the variations of iron losses due to possible variations in the stator core characteristics. Simulation results demonstrated that the observer and the adaptive scheme showed a good performance fulfilling then the objectives. (author)
王蕾; 吴光英
2012-01-01
分析了等温淬火球铁（ADI）等温转变过程及影响因素，介绍了奥一贝球铁等温淬火设备，包括推杆式、立式、箱式等温淬火连续生产线，并对国内外等温淬火生产线进行了对比。%The isothermal transformation of austempered ductile iron and main influence factors were described. The austempered ductile iron continuous production lines, including pusher type, vertical type and box type were introduced, and the ADI production lines at home and abroad were compared.
Relativistic quantum mechanics; Mecanique quantique relativiste
Ollitrault, J.Y. [CEA Saclay, 91 - Gif-sur-Yvette (France). Service de Physique Theorique]|[Universite Pierre et Marie Curie, 75 - Paris (France)
1998-12-01
These notes form an introduction to relativistic quantum mechanics. The mathematical formalism has been reduced to the minimum in order to enable the reader to calculate elementary physical processes. The second quantification and the field theory are the logical followings of this course. The reader is expected to know analytical mechanics (Lagrangian and Hamiltonian), non-relativistic quantum mechanics and some basis of restricted relativity. The purpose of the first 3 chapters is to define the quantum mechanics framework for already known notions about rotation transformations, wave propagation and restricted theory of relativity. The next 3 chapters are devoted to the application of relativistic quantum mechanics to a particle with 0,1/5 and 1 spin value. The last chapter deals with the processes involving several particles, these processes require field theory framework to be thoroughly described. (A.C.) 2 refs.
Towards relativistic quantum geometry
Ridao, Luis Santiago [Instituto de Investigaciones Físicas de Mar del Plata (IFIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata (Argentina); Bellini, Mauricio, E-mail: mbellini@mdp.edu.ar [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, C.P. 7600, Mar del Plata (Argentina); Instituto de Investigaciones Físicas de Mar del Plata (IFIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata (Argentina)
2015-12-17
We obtain a gauge-invariant relativistic quantum geometry by using a Weylian-like manifold with a geometric scalar field which provides a gauge-invariant relativistic quantum theory in which the algebra of the Weylian-like field depends on observers. An example for a Reissner–Nordström black-hole is studied.
Relativistic and Non-relativistic Equations of Motion
Mangiarotti, L
1998-01-01
It is shown that any second order dynamic equation on a configuration space $X$ of non-relativistic time-dependent mechanics can be seen as a geodesic equation with respect to some (non-linear) connection on the tangent bundle $TX\\to X$ of relativistic velocities. Using this fact, the relationship between relativistic and non-relativistic equations of motion is studied.
Development of an X-ray Telescope with a Large Effective Area for the Iron K Line Band
Matsumoto, Hironori; Tachibana, Sasagu; Yoshikawa, Shun; Tamura, Keisuke; Mori, Hideyuki; Mitsuishi, Ikuyuki; Tawara, Yuzuru; Kunieda, Hideyo; Yamashita, Kojun
2015-08-01
X-ray micro-calorimeters such as the Soft X-ray Spectrometer (SXS) on board ASTRO-H will enable precise spectroscopy of iron K lines even for spatially extended objects. To exploit the full power of the high-energy resolution, X-ray telescopes with a large effective area around 6 keV are essentially important. Conventional Wolter-I X-ray telescopes aimed at X-rays below 10 keV have used the principle of total reflection to collect the X-rays. Enlarging the diameter of this type of telescopes is not effective to obtain the large effective area, since the incident angle of X-rays for the outer part of the telescope exceeds the critical angle, and the X-ray reflectivity of the outer part is significantly low. For example, the critical angle of Ir for an X-ray of 6 keV is 0.748 deg. Thus if we assume a focal length of 6 m for a Wolter-I optics using mirrors covered with Ir as a reflector, the mirrors the radial position of which are larger than 34 cm cannot reflect X-rays above 6 keV effectively. If multi-layer mirrors are applied to the outer part of the telescope, however, the X-ray reflectivity can be enhanced significantly by the principle of Bragg reflection. Our objective is to develop a Wolter-I X-ray telescope with an aperture of 110 cm and a focal length of 6 m, and make all mirrors in the telescope can reflect X-rays around 6 keV effectively by utilizing the multi-layer mirrors. The size of the telescope is determined by a boundary condition that can be launched by the epsilon rocket of ISAS/JAXA. The multi-layer is designed to enhance the reflectivity at 6.4 keV, 6.7 keV, or 6.9 keV. Our simulation suggests that the effective area averaged in the 5.7-7.7 keV band could be 2000 cm2, whichis comparable to the effective area of Athena launched in 2028 by ESA. Furthermore, we showed that the Ir/C multi-layers produced by our DC magnetron sputtering machine has a surface roughness of less than 4 angstrom. This value is smaller than the average surface roughness
Relativistic spherical plasma waves
Bulanov, S. S.; Maksimchuk, A.; Schroeder, C. B.; Zhidkov, A. G.; Esarey, E.; Leemans, W. P.
2012-02-01
Tightly focused laser pulses that diverge or converge in underdense plasma can generate wake waves, having local structures that are spherical waves. Here we study theoretically and numerically relativistic spherical wake waves and their properties, including wave breaking.
Relativistic GLONASS and geodesy
Mazurova, E. M.; Kopeikin, S. M.; Karpik, A. P.
2016-12-01
GNSS technology is playing a major role in applications to civil, industrial and scientific areas. Nowadays, there are two fully functional GNSS: American GPS and Russian GLONASS. Their data processing algorithms have been historically based on the Newtonian theory of space and time with only a few relativistic effects taken into account as small corrections preventing the system from degradation on a fairly long time. Continuously growing accuracy of geodetic measurements and atomic clocks suggests reconsidering the overall approach to the GNSS theoretical model based on the Einstein theory of general relativity. This is essentially more challenging but fundamentally consistent theoretical approach to relativistic space geodesy. In this paper, we overview the basic principles of the relativistic GNSS model and explain the advantages of such a system for GLONASS and other positioning systems. Keywords: relativistic GLONASS, Einstein theory of general relativity.
Bliokh, Konstantin Y
2011-01-01
We consider the relativistic deformation of quantum waves and mechanical bodies carrying intrinsic angular momentum (AM). When observed in a moving reference frame, the centroid of the object undergoes an AM-dependent transverse shift. This is the relativistic analogue of the spin Hall effect, which occurs in free space without any external fields. Remarkably, the shifts of the geometric and energy centroids differ by a factor of 2, and both centroids are crucial for the correct Lorentz transformations of the AM tensor. We examine manifestations of the relativistic Hall effect in quantum vortices, mechanical flywheel, and discuss various fundamental aspects of the phenomenon. The perfect agreement of quantum and relativistic approaches allows applications at strikingly different scales: from elementary spinning particles, through classical light, to rotating black-holes.
Minas Bakalchev
2015-10-01
Full Text Available The perception of elements in a system often creates their interdependence, interconditionality, and suppression. The lines from a basic geometrical element have become the model of a reductive world based on isolation according to certain criteria such as function, structure, and social organization. Their traces are experienced in the contemporary world as fragments or ruins of a system of domination of an assumed hierarchical unity. How can one release oneself from such dependence or determinism? How can the lines become less “systematic” and forms more autonomous, and less reductive? How is a form released from modernistic determinism on the new controversial ground? How can these elements or forms of representation become forms of action in the present complex world? In this paper, the meaning of lines through the ideas of Le Corbusier, Leonidov, Picasso, and Hitchcock is presented. Spatial research was made through a series of examples arising from the projects of the architectural studio “Residential Transformations”, which was a backbone for mapping the possibilities ranging from playfulness to exactness, as tactics of transformation in the different contexts of the contemporary world.
Exact Relativistic 'Antigravity' Propulsion
Felber, F S
2006-01-01
The Schwarzschild solution is used to find the exact relativistic motion of a payload in the gravitational field of a mass moving with constant velocity. At radial approach or recession speeds faster than 3^-1/2 times the speed of light, even a small mass gravitationally repels a payload. At relativistic speeds, a suitable mass can quickly propel a heavy payload from rest nearly to the speed of light with negligible stresses on the payload.
Exact Relativistic `Antigravity' Propulsion
Felber, Franklin S.
2006-01-01
The Schwarzschild solution is used to find the exact relativistic motion of a payload in the gravitational field of a mass moving with constant velocity. At radial approach or recession speeds faster than 3-1/2 times the speed of light, even a small mass gravitationally repels a payload. At relativistic speeds, a suitable mass can quickly propel a heavy payload from rest nearly to the speed of light with negligible stresses on the payload.
Relativistic quantum revivals.
Strange, P
2010-03-26
Quantum revivals are now a well-known phenomena within nonrelativistic quantum theory. In this Letter we display the effects of relativity on revivals and quantum carpets. It is generally believed that revivals do not occur within a relativistic regime. Here we show that while this is generally true, it is possible, in principle, to set up wave packets with specific mathematical properties that do exhibit exact revivals within a fully relativistic theory.
Relativistic viscoelastic fluid mechanics.
Fukuma, Masafumi; Sakatani, Yuho
2011-08-01
A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.
A relativistically broadened O VIII Lyalpha line in the ultra-compact X-ray binary 4U 0614+091
Madej, O K; Fabian, A C; Pinto, C; Verbunt, F; de Plaa, J
2010-01-01
Ultra-compact X-ray binaries consist of a neutron star or black hole that accretes material from a white dwarf-donor star. The ultra-compact nature is expressed in very short orbital periods of less than 1 hour. In the case of 4U 0614+091 oxygen-rich material from a CO or ONe white dwarf is flowing to the neutron star. This oxygen-rich disc can reflect X-rays emitted by the neutron star giving a characteristic emission spectrum. We have analyzed high-resolution RGS and broad band EPIC spectra of 4U 0614+091 obtained by the XMM-Newton satellite. We detect a broad emission feature at ~0.7 keV in both instruments, which cannot be explained by unusual abundances of oxygen and neon in the line of sight, as proposed before in the literature. We interpret this feature as O VIII Lyalpha emission caused by reflection of X-rays off highly ionized oxygen, in the strong gravitational field close to the neutron star.
Marinucci, A.; Matt, G.; Bianchi, S.
2015-01-01
We present NuSTAR observations of the bright Seyfert 2 galaxy NGC 2110 obtained in 2012, when the source was at the highest flux level ever observed, and in 2013, when the source was at a more typical flux level. We include archival observations from other X-ray satellites, namely XMM-Newton, Suz......We present NuSTAR observations of the bright Seyfert 2 galaxy NGC 2110 obtained in 2012, when the source was at the highest flux level ever observed, and in 2013, when the source was at a more typical flux level. We include archival observations from other X-ray satellites, namely XMM...... is found and, by using temporal information collected over more than a decade, we investigate variations of the iron Kα line on time-scales of years. The Fe K alpha line is likely the sum of two components: one constant (originating from distant Compton-thick material) and the other one variable...
Single electron relativistic clock interferometer
Bushev, P. A.; Cole, J. H.; Sholokhov, D.; Kukharchyk, N.; Zych, M.
2016-09-01
Although time is one of the fundamental notions in physics, it does not have a unique description. In quantum theory time is a parameter ordering the succession of the probability amplitudes of a quantum system, while according to relativity theory each system experiences in general a different proper time, depending on the system's world line, due to time dilation. It is therefore of fundamental interest to test the notion of time in the regime where both quantum and relativistic effects play a role, for example, when different amplitudes of a single quantum clock experience different magnitudes of time dilation. Here we propose a realization of such an experiment with a single electron in a Penning trap. The clock can be implemented in the electronic spin precession and its time dilation then depends on the radial (cyclotron) state of the electron. We show that coherent manipulation and detection of the electron can be achieved already with present day technology. A single electron in a Penning trap is a technologically ready platform where the notion of time can be probed in a hitherto untested regime, where it requires a relativistic as well as quantum description.
Relativistic theories of materials
Bressan, Aldo
1978-01-01
The theory of relativity was created in 1905 to solve a problem concerning electromagnetic fields. That solution was reached by means of profound changes in fundamental concepts and ideas that considerably affected the whole of physics. Moreover, when Einstein took gravitation into account, he was forced to develop radical changes also in our space-time concepts (1916). Relativistic works on heat, thermodynamics, and elasticity appeared as early as 1911. However, general theories having a thermodynamic basis, including heat conduction and constitutive equations, did not appear in general relativity until about 1955 for fluids and appeared only after 1960 for elastic or more general finitely deformed materials. These theories dealt with materials with memory, and in this connection some relativistic versions of the principle of material indifference were considered. Even more recently, relativistic theories incorporating finite deformations for polarizable and magnetizable materials and those in which couple s...
Relativistic Quantum Communication
Hosler, Dominic
2013-01-01
In this Ph.D. thesis, I investigate the communication abilities of non-inertial observers and the precision to which they can measure parametrized states. I introduce relativistic quantum field theory with field quantisation, and the definition and transformations of mode functions in Minkowski, Schwarzschild and Rindler spaces. I introduce information theory by discussing the nature of information, defining the entropic information measures, and highlighting the differences between classical and quantum information. I review the field of relativistic quantum information. We investigate the communication abilities of an inertial observer to a relativistic observer hovering above a Schwarzschild black hole, using the Rindler approximation. We compare both classical communication and quantum entanglement generation of the state merging protocol, for both the single and dual rail encodings. We find that while classical communication remains finite right up to the horizon, the quantum entanglement generation tend...
Relativistic quantum mechanics
Horwitz, Lawrence P
2015-01-01
This book describes a relativistic quantum theory developed by the author starting from the E.C.G. Stueckelberg approach proposed in the early 40s. In this framework a universal invariant evolution parameter (corresponding to the time originally postulated by Newton) is introduced to describe dynamical evolution. This theory is able to provide solutions for some of the fundamental problems encountered in early attempts to construct a relativistic quantum theory. A relativistically covariant construction is given for which particle spins and angular momenta can be combined through the usual rotation group Clebsch-Gordan coefficients. Solutions are defined for both the classical and quantum two body bound state and scattering problems. The recently developed quantum Lax-Phillips theory of semigroup evolution of resonant states is described. The experiment of Lindner and coworkers on interference in time is discussed showing how the property of coherence in time provides a simple understanding of the results. Th...
Bambi, Cosimo
2013-01-01
Under the assumption that astrophysical black hole candidates are the Kerr black holes of general relativity, the continuum-fitting method and the analysis of the K$\\alpha$ iron line are today the only available techniques capable of providing a relatively reliable estimate of the spin parameter of these objects. If we relax the Kerr black hole hypothesis and we try to test the nature of black hole candidates, we find that there is a strong correlation between the measurement of the spin and possible deviations from the Kerr solution. The properties of the radiation emitted in a Kerr spacetime with spin parameter $a_*$ are indeed very similar, and practically indistinguishable, from the ones of the radiation emitted around a non-Kerr object with different spin. In this paper, I address the question whether measuring the Kerr spin with both the continuum-fitting method and the K$\\alpha$ iron line analysis of the same object can be used to claim the Kerr nature of the black hole candidate in the case of consist...
Handbook of relativistic quantum chemistry
Liu, Wenjian (ed.) [Peking Univ., Beijing (China). Center for Computational Science and Engineering
2017-03-01
This handbook focuses on the foundations of relativistic quantum mechanics and addresses a number of fundamental issues never covered before in a book. For instance: How can many-body theory be combined with quantum electrodynamics? How can quantum electrodynamics be interfaced with relativistic quantum chemistry? What is the most appropriate relativistic many-electron Hamiltonian? How can we achieve relativistic explicit correlation? How can we formulate relativistic properties? - just to name a few. Since relativistic quantum chemistry is an integral component of computational chemistry, this handbook also supplements the ''Handbook of Computational Chemistry''. Generally speaking, it aims to establish the 'big picture' of relativistic molecular quantum mechanics as the union of quantum electrodynamics and relativistic quantum chemistry. Accordingly, it provides an accessible introduction for readers new to the field, presents advanced methodologies for experts, and discusses possible future perspectives, helping readers understand when/how to apply/develop the methodologies.
Relativistic electronic dressing
Attaourti, Y
2002-01-01
We study the effects of the relativistic electronic dressing in laser-assisted electron-hydrogen atom elastic collisions. We begin by considering the case when no radiation is present. This is necessary in order to check the consistency of our calculations and we then carry out the calculations using the relativistic Dirac-Volkov states. It turns out that a simple formal analogy links the analytical expressions of the differential cross section without laser and the differential cross section in presence of a laser field.
Relativistic Rotating Vector Model
Lyutikov, Maxim
2016-01-01
The direction of polarization produced by a moving source rotates with the respect to the rest frame. We show that this effect, induced by pulsar rotation, leads to an important correction to polarization swings within the framework of rotating vector model (RVM); this effect has been missed by previous works. We construct relativistic RVM taking into account finite heights of the emission region that lead to aberration, time-of-travel effects and relativistic rotation of polarization. Polarizations swings at different frequencies can be used, within the assumption of the radius-to-frequency mapping, to infer emission radii and geometry of pulsars.
The special relativistic shock tube
Thompson, Kevin W.
1986-01-01
The shock-tube problem has served as a popular test for numerical hydrodynamics codes. The development of relativistic hydrodynamics codes has created a need for a similar test problem in relativistic hydrodynamics. The analytical solution to the special relativistic shock-tube problem is presented here. The relativistic shock-jump conditions and rarefaction solution which make up the shock tube are derived. The Newtonian limit of the calculations is given throughout.
Bruce, Adam L
2015-01-01
We show the traditional rocket problem, where the ejecta velocity is assumed constant, can be reduced to an integral quadrature of which the completely non-relativistic equation of Tsiolkovsky, as well as the fully relativistic equation derived by Ackeret, are limiting cases. By expanding this quadrature in series, it is shown explicitly how relativistic corrections to the mass ratio equation as the rocket transitions from the Newtonian to the relativistic regime can be represented as products of exponential functions of the rocket velocity, ejecta velocity, and the speed of light. We find that even low order correction products approximate the traditional relativistic equation to a high accuracy in flight regimes up to $0.5c$ while retaining a clear distinction between the non-relativistic base-case and relativistic corrections. We furthermore use the results developed to consider the case where the rocket is not moving relativistically but the ejecta stream is, and where the ejecta stream is massless.
Relativistic cosmology; Cosmologia Relativista
Bastero-Gil, M.
2015-07-01
Relativistic cosmology is nothing but the study of the evolution of our universe expanding from the General Theory of Relativity, which describes the gravitational interaction at any scale and given its character far-reaching is the force that dominate the evolution of the universe. (Author)
Relativistic impulse dynamics.
Swanson, Stanley M
2011-08-01
Classical electrodynamics has some annoying rough edges. The self-energy of charges is infinite without a cutoff. The calculation of relativistic trajectories is difficult because of retardation and an average radiation reaction term. By reconceptuallizing electrodynamics in terms of exchanges of impulses rather than describing it by forces and potentials, we eliminate these problems. A fully relativistic theory using photonlike null impulses is developed. Numerical calculations for a two-body, one-impulse-in-transit model are discussed. A simple relationship between center-of-mass scattering angle and angular momentum was found. It reproduces the Rutherford cross section at low velocities and agrees with the leading term of relativistic distinguishable-particle quantum cross sections (Møller, Mott) when the distance of closest approach is larger than the Compton wavelength of the particle. Magnetism emerges as a consequence of viewing retarded and advanced interactions from the vantage point of an instantaneous radius vector. Radiation reaction becomes the local conservation of energy-momentum between the radiating particle and the emitted impulse. A net action is defined that could be used in developing quantum dynamics without potentials. A reinterpretation of Newton's laws extends them to relativistic motion.
Antippa, Adel F.
2009-01-01
We solve the problem of the relativistic rocket by making use of the relation between Lorentzian and Galilean velocities, as well as the laws of superposition of successive collinear Lorentz boosts in the limit of infinitesimal boosts. The solution is conceptually simple, and technically straightforward, and provides an example of a powerful…
Relativistic length agony continued
Redžić D.V.
2014-01-01
Full Text Available We made an attempt to remedy recent confusing treatments of some basic relativistic concepts and results. Following the argument presented in an earlier paper (Redžić 2008b, we discussed the misconceptions that are recurrent points in the literature devoted to teaching relativity such as: there is no change in the object in Special Relativity, illusory character of relativistic length contraction, stresses and strains induced by Lorentz contraction, and related issues. We gave several examples of the traps of everyday language that lurk in Special Relativity. To remove a possible conceptual and terminological muddle, we made a distinction between the relativistic length reduction and relativistic FitzGerald-Lorentz contraction, corresponding to a passive and an active aspect of length contraction, respectively; we pointed out that both aspects have fundamental dynamical contents. As an illustration of our considerations, we discussed briefly the Dewan-Beran-Bell spaceship paradox and the ‘pole in a barn’ paradox. [Projekat Ministarstva nauke Republike Srbije, br. 171028
Alba, David; Lusanna, Luca
2009-01-01
A new formulation of relativistic quantum mechanics is proposed in the framework of the rest-frame instant form of dynamics with its instantaneous Wigner 3-spaces and with its description of the particle world-lines by means of derived non-canonical predictive coordinates. In it we quantize the frozen Jacobi data of the non-local 4-center of mass and the Wigner-covariant relative variables in an abstract (frame-independent) internal space whose existence is implied by Wigner-covariance. The formalism takes care of the properties of both relativistic bound states and scattering ones. There is a natural solution to the \\textit{relativistic localization problem}. The non-relativistic limit leads to standard quantum mechanics but with a frozen Hamilton-Jacobi description of the center of mass. Due to the \\textit{non-locality} of the Poincar\\'e generators the resulting theory of relativistic entanglement is both \\textit{kinematically non-local and spatially non-separable}: these properties, absent in the non-relat...
Road and Street Centerlines, State Line, Published in 2007, 1:24000 (1in=2000ft) scale, Iron County.
NSGIC GIS Inventory (aka Ramona) — , published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2007. It is described as 'State Line'. The extent of these data...
Hydrography, quichn83-line, Published in 2006, 1:24000 (1in=2000ft) scale, Iron County.
NSGIC GIS Inventory (aka Ramona) — This Hydrography dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2006. It is described as 'quichn83-line'....
Water Distribution Lines, water dist 10, Published in 2003, 1:24000 (1in=2000ft) scale, Iron County.
NSGIC GIS Inventory (aka Ramona) — This Water Distribution Lines dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2003. It is described as...
NSGIC GIS Inventory (aka Ramona) — This Transmission Lines or Poles, Electric dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2005. It is...
Scale heights and equivalent widths of the iron K-shell lines in the Galactic diffuse X-ray emission
Yamauchi, Shigeo; Nobukawa, Masayoshi; Uchiyama, Hideki; Koyama, Katsuji
2016-01-01
This paper reports the analysis of the X-ray spectra of the Galactic diffuse X-ray emission (GDXE) in the Suzaku archive. The fluxes of the Fe I K alpha (6.4 keV), Fe XXV,He alpha (6.7 keV) and Fe XXVI Ly alpha (6.97 keV) lines are separately determined. From the latitude distributions, we confirm that the GDXE is decomposed into the Galactic center (GCXE), the Galactic bulge (GBXE) and the Galactic ridge (GRXE) X-ray emissions. The scale heights (SHs) of the Fe XXV He alpha line of the GCXE, GBXE and GRXE are determined to be ~40, ~310 and ~140 pc, while those of the Fe I K alpha line are ~30, ~160 and ~70 pc, respectively. The mean equivalent widths (EWs) of the sum of the Fe XXV He alpha and Fe XXVI Ly alpha lines are ~750 eV, ~600 eV and ~550 eV, while those of the Fe I K alpha line are ~150~eV, ~60~eV and ~100~eV for the GCXE, GBXE and GRXE, respectively. The origin of the GBXE, GRXE and GCXE is separately discussed based on the new results of the SHs and EWs, in comparison with those of the Cataclysmic ...
Ezzeddine, Rana; Frebel, Anna; Plez, Bertrand
2017-10-01
We present new ultra-metal-poor stars parameters with [Fe/H] up-to-date iron model atom with a new recipe for non-elastic hydrogen collision rates. We study the departures from LTE in their atmospheric parameters and show that they can grow up to ∼1.00 dex in [Fe/H], ∼150 K in {T}{eff} and ∼0.5 dex in log g toward the lowest metallicities. Accurate NLTE atmospheric stellar parameters, in particular [Fe/H] being significantly higher, are the first step to eventually providing full NLTE abundance patterns that can be compared with Population III supernova nucleosynthesis yields to derive properties of the first stars. Overall, this maximizes the potential of these likely second-generation stars to investigate the early universe and how the chemical elements were formed.
Spatial and Temporal Variations of the Diffuse Iron 6.4 keV Line in the Galactic Center Region
Chernyshov, D O; Nobukawa, M; Tsuru, T G; Koyama, K; Uchiyama, H; Matsumoto, H
2011-01-01
We analyze the diffuse Fe I K-alpha line generated in the diffuse interstellar molecular hydrogen by primary photons or subrelativistic protons injected by Sagittarius (Sgr) A*. We showed that unlike emission from compact molecular clouds, this emission can be permanently observed in the directions of the Galactic center. We conclude that the diffuse emission of 6.4 keV line observed at present is probably due to Fe I K-alpha vacancy production by primary photons if the X-ray luminosity of Sgr A* was about Lx ~ 10^39-10^40 erg/s. In principle these data can also be described in the framework of the model when the 6.4 keV line emission is generated by subrelativistic protons generated by accretion onto the central black hole but in this case extreme parameters of this model are necessary.
Relativistic Effects on Reflection X-ray Spectra of AGN
Lee, Khee-Gan; /University Coll. London; Fuerst, Steven V.; /KIPAC, Menlo Park; Brandwardi-Raymond, Graziella; Wu, Kinwah; Crowley, Oliver; /University Coll. London
2007-01-05
We have calculated the reflection component of the X-ray spectra of active galactic nuclei (AGN) and shown that they can be significantly modified by the relativistic motion of the accretion flow and various gravitational effects of the central black hole. The absorption edges in the reflection spectra suffer severe energy shifts and smearing. The degree of distortion depends on the system parameters, and the dependence is stronger for some parameters such as the inner radius of the accretion disk and the disk viewing inclination angles. The relativistic effects are significant and are observable. Improper treatment of the reflection component of the X-ray continuum in spectral fittings will give rise to spurious line-like features, which will mimic the fluorescent emission lines and mask the relativistic signatures of the lines.
Numerical Simulations of Driven Supersonic Relativistic MHD Turbulence
Zrake, Jonathan; 10.1063/1.3621748
2011-01-01
Models for GRB outflows invoke turbulence in relativistically hot magnetized fluids. In order to investigate these conditions we have performed high-resolution three-dimensional numerical simulations of relativistic magneto-hydrodynamical (RMHD) turbulence. We find that magnetic energy is amplified to several percent of the total energy density by turbulent twisting and folding of magnetic field lines. Values of epsilon_B near 1% are thus naturally expected. We study the dependence of saturated magnetic field energy fraction as a function of Mach number and relativistic temperature. We then present power spectra of the turbulent kinetic and magnetic energies. We also present solenoidal (curl-like) and dilatational (divergence-like) power spectra of kinetic energy. We propose that relativistic effects introduce novel couplings between these spectral components. The case we explore in most detail is for equal amounts of thermal and rest mass energy, corresponding to conditions after collisions of shells with re...
Scaling of Magnetic Reconnection in Relativistic Collisionless Pair Plasmas
Liu, Yi-Hsin; Guo, Fan; Daughton, William; Li, Hui; Hesse, Michael
2015-01-01
Using fully kinetic simulations, we study the scaling of the inflow speed of collisionless magnetic reconnection in electron-positron plasmas from the non-relativistic to ultra-relativistic limit. In the anti-parallel configuration, the inflow speed increases with the upstream magnetization parameter sigma and approaches the speed of light when sigma is greater than O(100), leading to an enhanced reconnection rate. In all regimes, the divergence of the pressure tensor is the dominant term responsible for breaking the frozen-in condition at the x-line. The observed scaling agrees well with a simple model that accounts for the Lorentz contraction of the plasma passing through the diffusion region. The results demonstrate that the aspect ratio of the diffusion region, modified by the compression factor of proper density, remains approximately 0.1 in both the non-relativistic and relativistic limits.
Relativistic Hydrodynamics with Wavelets
DeBuhr, Jackson; Anderson, Matthew; Neilsen, David; Hirschmann, Eric W
2015-01-01
Methods to solve the relativistic hydrodynamic equations are a key computational kernel in a large number of astrophysics simulations and are crucial to understanding the electromagnetic signals that originate from the merger of astrophysical compact objects. Because of the many physical length scales present when simulating such mergers, these methods must be highly adaptive and capable of automatically resolving numerous localized features and instabilities that emerge throughout the computational domain across many temporal scales. While this has been historically accomplished with adaptive mesh refinement (AMR) based methods, alternatives based on wavelet bases and the wavelet transformation have recently achieved significant success in adaptive representation for advanced engineering applications. This work presents a new method for the integration of the relativistic hydrodynamic equations using iterated interpolating wavelets and introduces a highly adaptive implementation for multidimensional simulati...
Compton reflection and iron fluorescence in AGN and GBHCs
Reynolds, C S
1998-01-01
Any cold, optically-thick matter in the vicinity of an accreting black hole, such as the accretion disk, can intercept and reprocess some fraction of the hard X-ray continuum emission, thereby imprinting atomic features into the observed spectrum. This process of `X-ray reflection' primarily gives rise to a broad reflection `hump' peaking at 30keV and an iron emission line at 6.4keV. In this review, I briefly describe the physics of this process before reviewing the observations of these features in active galactic nuclei (AGN) and Galactic black hole candidates (GBHCs). In some AGN, Seyfert galaxies in particular, the iron line is found to be very broad and asymmetric. It is believed that such lines arise from the innermost regions of the accretion disk, with mildly-relativistic Doppler shifts and gravitational redshifts combining to produce the line profile. Hence, such lines give us a direct observational probe of the region within several gravitational radii of the black hole. The complications that plagu...
Tomankova K
2015-01-01
Full Text Available Katerina Tomankova,1 Katerina Polakova,2 Klara Pizova,1 Svatopluk Binder,1 Marketa Havrdova,2 Mary Kolarova,2 Eva Kriegova,3 Jana Zapletalova,1 Lukas Malina,1 Jana Horakova,1 Jakub Malohlava,1 Argiris Kolokithas-Ntoukas,4 Aristides Bakandritsos,4 Hana Kolarova,1 Radek Zboril2 1Department of Medical Biophysics, Institute of Translation Medicine, Faculty of Medicine and Dentistry, 2Regional Centre of Advanced Technologies and Materials, Departments of Physical Chemistry and Experimental Physics, Faculty of Science, 3Department of Immunology, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic; 4Department of Materials Science, University of Patras, Patras, Greece Abstract: One of the promising strategies for improvement of cancer treatment is based on magnetic drug delivery systems, thus avoiding side effects of standard chemotherapies. Superparamagnetic iron oxide (SPIO nanoparticles have ideal properties to become a targeted magnetic drug delivery contrast probes, named theranostics. We worked with SPIO condensed colloidal nanocrystal clusters (MagAlg prepared through a new soft biomineralization route in the presence of alginate as the polymeric shell and loaded with doxorubicin (DOX. The aim of this work was to study the in vitro cytotoxicity of these new MagAlg–DOX systems on mouse fibroblast and breast carcinoma cell lines. For proper analysis and understanding of cell behavior after administration of MagAlg–DOX compared with free DOX, a complex set of in vitro tests, including production of reactive oxygen species, comet assay, cell cycle determination, gene expression, and cellular uptake, were utilized. It was found that the cytotoxic effect of MagAlg–DOX system is delayed compared to free DOX in both cell lines. This was attributed to the different mechanism of internalization of DOX and MagAlg–DOX into the cells, together with the fact that the drug is strongly bound on the drug nanocarriers. We
Relativistic heavy ion reactions
Brink, D.M.
1989-08-01
The theory of quantum chromodynamics predicts that if nuclear matter is heated to a sufficiently high temperature then quarks might become deconfined and a quark-gluon plasma could be produced. One of the aims of relativistic heavy ion experiments is to search for this new state of matter. These lectures survey some of the new experimental results and give an introduction to the theories used to interpret them. 48 refs., 4 tabs., 11 figs.
Relativistic spherical plasma waves
Bulanov, S S; Schroeder, C B; Zhidkov, A G; Esarey, E; Leemans, W P
2011-01-01
Tightly focused laser pulses as they diverge or converge in underdense plasma can generate wake waves, having local structures that are spherical waves. Here we report on theoretical study of relativistic spherical wake waves and their properties, including wave breaking. These waves may be suitable as particle injectors or as flying mirrors that both reflect and focus radiation, enabling unique X-ray sources and nonlinear QED phenomena.
Relativistic Quantum Noninvasive Measurements
Bednorz, Adam
2014-01-01
Quantum weak, noninvasive measurements are defined in the framework of relativity. Invariance with respect to reference frame transformations of the results in different models is discussed. Surprisingly, the bare results of noninvasive measurements are invariant for certain class of models, but not the detection error. Consequently, any stationary quantum realism based on noninvasive measurements will break, at least spontaneously, relativistic invariance and correspondence principle at zero temperature.
Relativistic cosmological hydrodynamics
Hwang, J
1997-01-01
We investigate the relativistic cosmological hydrodynamic perturbations. We present the general large scale solutions of the perturbation variables valid for the general sign of three space curvature, the cosmological constant, and generally evolving background equation of state. The large scale evolution is characterized by a conserved gauge invariant quantity which is the same as a perturbed potential (or three-space curvature) in the comoving gauge.
Relativistic gravity gradiometry
Bini, Donato; Mashhoon, Bahram
2016-12-01
In general relativity, relativistic gravity gradiometry involves the measurement of the relativistic tidal matrix, which is theoretically obtained from the projection of the Riemann curvature tensor onto the orthonormal tetrad frame of an observer. The observer's 4-velocity vector defines its local temporal axis and its local spatial frame is defined by a set of three orthonormal nonrotating gyro directions. The general tidal matrix for the timelike geodesics of Kerr spacetime has been calculated by Marck [Proc. R. Soc. A 385, 431 (1983)]. We are interested in the measured components of the curvature tensor along the inclined "circular" geodesic orbit of a test mass about a slowly rotating astronomical object of mass M and angular momentum J . Therefore, we specialize Marck's results to such a "circular" orbit that is tilted with respect to the equatorial plane of the Kerr source. To linear order in J , we recover the gravitomagnetic beating phenomenon [B. Mashhoon and D. S. Theiss, Phys. Rev. Lett. 49, 1542 (1982)], where the beat frequency is the frequency of geodetic precession. The beat effect shows up as a special long-period gravitomagnetic part of the relativistic tidal matrix; moreover, the effect's short-term manifestations are contained in certain post-Newtonian secular terms. The physical interpretation of this effect is briefly discussed.
Gravitationally confined relativistic neutrinos
Vayenas, C. G.; Fokas, A. S.; Grigoriou, D.
2017-09-01
Combining special relativity, the equivalence principle, and Newton’s universal gravitational law with gravitational rather than rest masses, one finds that gravitational interactions between relativistic neutrinos with kinetic energies above 50 MeV are very strong and can lead to the formation of gravitationally confined composite structures with the mass and other properties of hadrons. One may model such structures by considering three neutrinos moving symmetrically on a circular orbit under the influence of their gravitational attraction, and by assuming quantization of their angular momentum, as in the Bohr model of the H atom. The model contains no adjustable parameters and its solution, using a neutrino rest mass of 0.05 eV/c2, leads to composite state radii close to 1 fm and composite state masses close to 1 GeV/c2. Similar models of relativistic rotating electron - neutrino pairs give a mass of 81 GeV/c2, close to that of W bosons. This novel mechanism of generating mass suggests that the Higgs mass generation mechanism can be modeled as a latent gravitational field which gets activated by relativistic neutrinos.
Relativistic Radiation Mediated Shocks
Budnik, Ran; Sagiv, Amir; Waxman, Eli
2010-01-01
The structure of relativistic radiation mediated shocks (RRMS) propagating into a cold electron-proton plasma is calculated and analyzed. A qualitative discussion of the physics of relativistic and non relativistic shocks, including order of magnitude estimates for the relevant temperature and length scales, is presented. Detailed numerical solutions are derived for shock Lorentz factors $\\Gamma_u$ in the range $6\\le\\Gamma_u\\le30$, using a novel iteration technique solving the hydrodynamics and radiation transport equations (the protons, electrons and positrons are argued to be coupled by collective plasma processes and are treated as a fluid). The shock transition (deceleration) region, where the Lorentz factor $ \\Gamma $ drops from $ \\Gamma_u $ to $ \\sim 1 $, is characterized by high plasma temperatures $ T\\sim \\Gamma m_ec^2 $ and highly anisotropic radiation, with characteristic shock-frame energy of upstream and downstream going photons of a few~$\\times\\, m_ec^2$ and $\\sim \\Gamma^2 m_ec^2$, respectively.P...
Parker, Edward
2017-08-01
A nonrelativistic particle released from rest at the edge of a ball of uniform charge density or mass density oscillates with simple harmonic motion. We consider the relativistic generalizations of these situations where the particle can attain speeds arbitrarily close to the speed of light; generalizing the electrostatic and gravitational cases requires special and general relativity, respectively. We find exact closed-form relations between the position, proper time, and coordinate time in both cases, and find that they are no longer harmonic, with oscillation periods that depend on the amplitude. In the highly relativistic limit of both cases, the particle spends almost all of its proper time near the turning points, but almost all of the coordinate time moving through the bulk of the ball. Buchdahl's theorem imposes nontrivial constraints on the general-relativistic case, as a ball of given density can only attain a finite maximum radius before collapsing into a black hole. This article is intended to be pedagogical, and should be accessible to those who have taken an undergraduate course in general relativity.
Lipka, Marko; Wu, Zijun; Escher, Peter; Struck, Ulrich; Dellwig, Olaf; Schafmeister, Maria; Böttcher*, Michael E.
2013-04-01
preferentially desorbed from the aqueous solution. The changes in the stream composition lead to the formation of iron(oxyhyr)oxide precipitates in the stream bed before the waters pass to underground drainage into a subterranean mixing zone with brackish BS waters. These ochrous precipitates act as a sink for dissolved phosphate and minor calcium. P : Fe ratios and Ca : Fe ratios are about 0.08 and 0.2, respectively, which are caused by P adsorption and a mixture with minor CaCO3 and/or Ca-phosphate. The investigation reveals that the surface precipitation on the beach leads to the formation of SGD essentially free of dissolved iron and strongly depleted in phosphate. Similar iron phases may also be an important part of the subterranean estuary supposed at that coast line, where retention of nutrients and heavy metals by iron(oxyhydr)oxides could influence the release of nutrients into the coastal ecosystem. Fe- and P-rich surface precipitates, however, are transported in suspension into the Baltic Sea during wind-driven flood events. Acknowledgements: This work was partly supported by the BONUS+ project AMBER and the Leibniz IOW.
Point form relativistic quantum mechanics and relativistic SU(6)
Klink, W. H.
1993-01-01
The point form is used as a framework for formulating a relativistic quantum mechanics, with the mass operator carrying the interactions of underlying constituents. A symplectic Lie algebra of mass operators is introduced from which a relativistic harmonic oscillator mass operator is formed. Mass splittings within the degenerate harmonic oscillator levels arise from relativistically invariant spin-spin, spin-orbit, and tensor mass operators. Internal flavor (and color) symmetries are introduced which make it possible to formulate a relativistic SU(6) model of baryons (and mesons). Careful attention is paid to the permutation symmetry properties of the hadronic wave functions, which are written as polynomials in Bargmann spaces.
Analysing the Suzaku spectra of the broad-line Seyfert 1 galaxy CBS 126
Chiang, Chia-Ying; Reis, R. C.; Fabian, A. C.; Grupe, D.; Tsuruta, S.
2012-09-01
We analysed new simultaneous Suzaku and Swift data of the broad-line Seyfert 1 (BLS1) galaxy CBS 126. A clear Fe emission line and a strong soft excess are present in the source spectra. We fit the spectra with a relativistic reflection model and find that the model tends to fit the data with a high iron abundance possibly due to the large soft excess present. By checking the difference and the rms spectra, we find that there is likely an absorption edge at ˜0.89 keV, which might be caused by oxygen or neon. We also produced an analysis of the time-resolved spectra in order to examine the existence of the edge. Although high iron abundance is required more in the time-resolved spectra, a model of solar iron abundance together with an absorption edge gives a more physical explanation. Variation of the ionization parameter is an alternative, plausible explanation for the excess seen in the difference spectra. It is difficult to know if there are warm absorbers in this source from the current data. To further investigate the presence of possible warm absorbers, higher signal-to-noise ratio low-energy data are needed. The work presented here tentatively suggests that the spectra of a BLS1 galaxy can be explained by a relativistic reflection model similar to that often seen in their narrow-line cousins.
Stochastic oscillations of general relativistic disks
Harko, Tiberiu
2012-01-01
We analyze the general relativistic oscillations of thin accretion disks around compact astrophysical objects interacting with the surrounding medium through non-gravitational forces. The interaction with the external medium (a thermal bath) is modeled via a friction force, and a random force, respectively. The general equations describing the stochastically perturbed disks are derived by considering the perturbations of trajectories of the test particles in equatorial orbits, assumed to move along the geodesic lines. By taking into account the presence of a viscous dissipation and of a stochastic force we show that the dynamics of the stochastically perturbed disks can be formulated in terms of a general relativistic Langevin equation. The stochastic energy transport equation is also obtained. The vertical oscillations of the disks in the Schwarzschild and Kerr geometries are considered in detail, and they are analyzed by numerically integrating the corresponding Langevin equations. The vertical displacement...
Arpita Ghosh; Somenath Chakrabarty
2011-09-01
Following an extremely interesting idea (Schieber 1984), published long ago, the work function associated with the emission of ultra-relativistic electrons from magnetically deformed metallic crystal (mainly iron) at the outer crust of a magnetar is obtained using relativistic version of Thomas–Fermi type model for electron distribution around the nuclei in this region. In the present scenario, surprisingly, the work function becomes anisotropic; the longitudinal part is an increasing function of magnetic field strength, whereas the transverse part diverges.
Relativistic magnetohydrodynamics in one dimension.
Lyutikov, Maxim; Hadden, Samuel
2012-02-01
We derive a number of solutions for one-dimensional dynamics of relativistic magnetized plasma that can be used as benchmark estimates in relativistic hydrodynamic and magnetohydrodynamic numerical codes. First, we analyze the properties of simple waves of fast modes propagating orthogonally to the magnetic field in relativistically hot plasma. The magnetic and kinetic pressures obey different equations of state, so that the system behaves as a mixture of gases with different polytropic indices. We find the self-similar solutions for the expansion of hot strongly magnetized plasma into vacuum. Second, we derive linear hodograph and Darboux equations for the relativistic Khalatnikov potential, which describe arbitrary one-dimensional isentropic relativistic motion of cold magnetized plasma and find their general and particular solutions. The obtained hodograph and Darboux equations are very powerful: A system of highly nonlinear, relativistic, time-dependent equations describing arbitrary (not necessarily self-similar) dynamics of highly magnetized plasma reduces to a single linear differential equation.
Spurious Shell Closures in the Relativistic Mean Field Model
Geng, L S; Toki, H; Long, W H; Shen, G
2006-01-01
Following a systematic theoretical study of the ground-state properties of over 7000 nuclei from the proton drip line to the neutron drip line in the relativistic mean field model [Prog. Theor. Phys. 113 (2005) 785], which is in fair agreement with existing experimental data, we observe a few spurious shell closures, i.e. proton shell closures at Z=58 and Z=92. These spurious shell closures are found to persist in all the effective forces of the relativistic mean field model, e.g. TMA, NL3, PKDD and DD-ME2.
S. G. Sandomirski
2008-01-01
Full Text Available The methods of correction of rejected limits of automated control line and automated sorting on processibility of unturned nipple castings of malleable cast iron KCh 30-6 on the basis of devices M axi-P is developed and implemented in production of Minsk plant of heating equipment.
Lyu, Ming; Méndez, Mariano; Sanna, Andrea; Homan, Jeroen; Belloni, Tomaso; Hiemstra, Beike
2014-01-01
We used six simultaneous XMM-Newton and Rossi X-ray Timing Explorer plus five Suzaku observations to study the continuum spectrum and the iron emission line in the neutron-star low-mass X-ray binary 4U 1636-53. We modelled the spectra with two thermal components (representing the accretion disc and
Lyu, Ming; Mendez, Mariano; Belloni, Tomaso; Homan, Jeroen; Sanna, Andrea; Hiemstra, Beike
2014-01-01
We used six simultaneous XMM-Newton and Rossi X-ray Timing Explorer plus five Suzaku observations to study the continuum spectrum and the iron emission line in the neutron-star low-mass X-ray binary 4U 1636-53 as a function of the position of the source in the colour-colour diagram. We modelled the
Lyu, Ming; Mendez, Mariano; Belloni, Tomaso; Homan, Jeroen; Sanna, Andrea; Hiemstra, Beike
2014-01-01
We used six simultaneous XMM-Newton and Rossi X-ray Timing Explorer plus five Suzaku observations to study the continuum spectrum and the iron emission line in the neutron-star low-mass X-ray binary 4U 1636-53 as a function of the position of the source in the colour-colour diagram. We modelled the
Bambi, Cosimo
2012-01-01
Astrophysical black hole candidates are thought to be the Kerr black holes predicted by General Relativity, but there is not yet a clear evidence that the geometry of the space-time around these objects is really described by the Kerr metric. In order to confirm the Kerr black hole hypothesis, we have to observe strong gravity features and check they are in agreement with the ones predicted by General Relativity. In this paper, I study what kind of information can be extracted by analyzing the broad K$\\alpha$ iron line, which is often seen in the X-ray spectrum of both stellar-mass and super-massive black hole candidates and whose shape is supposed to be strongly affected by the space-time geometry. I extend previous studies in the literature. It turns out that there is a strong degeneracy between the spin parameter and the deformation parameter; that is, the line emitted around a Kerr black hole with a certain spin can be very similar to the one coming from the space-time around a non-Kerr object with a quit...
Marinucci, A; Bianchi, S; Lu, T N; Arevalo, P; Baloković, M; Ballantyne, D; Bauer, F E; Boggs, S E; Christensen, F E; Craig, W W; Gandhi, P; Hailey, C J; Harrison, F; Puccetti, S; Rivers, E; Walton, D J; Stern, D; Zhang, W
2014-01-01
We present NuSTAR observations of the bright Seyfert 2 galaxy NGC 2110 obtained in 2012, when the source was at the highest flux level ever observed, and in 2013, when the source was at a more typical flux level. We include archival observations from other X-ray satellites, namely XMM-Newton, Suzaku, BeppoSAX, Chandra and Swift. Simultaneous NuSTAR and Swift broad band spectra (in the 3-80 keV range) indicate a cutoff energy $E_{\\rm c}>210$ keV, with no detectable contribution from Compton reflection. NGC 2110 is one of the very few sources where no evidence for distant Compton thick scattering is found and, by using temporal information collected over more than a decade, we investigate variations of the iron K$\\alpha$ line on time scales of years. The Fe K$\\alpha$ line is likely the sum of two components: one constant (originating from distant Compton-thick material) and the other one variable and linearly correlated with the source flux (possibly arising from Compton-thin material much closer to the black h...
Marinucci, A.; Matt, G.; Bianchi, S.; Lu, T. N.; Arevalo, P.; Balokovic, M.; Ballantyne, D.; Bauer, F. E.; Boggs, S. E.; Stern, D.; Zhang, William W.
2014-01-01
We present NuSTAR observations of the bright Seyfert 2 galaxy NGC 2110 obtained in 2012, when the source was at the highest flux level ever observed, and in 2013, when the source was at a more typical flux level. We include archival observations from other X-ray satellites, namely XMM-Newton, Suzaku, BeppoSAX, Chandra and Swift. Simultaneous NuSTAR and Swift broad band spectra (in the 3-80 keV range) indicate a cutoff energy E(sub c) greater than 210 keV, with no detectable contribution from Compton reflection. NGC 2110 is one of the very few sources where no evidence for distant Compton thick scattering is found and, by using temporal information collected over more than a decade, we investigate variations of the iron K(alpha) line on time scales of years. The Fe K alpha line is likely the sum of two components: one constant (originating from distant Compton-thick material) and the other one variable and linearly correlated with the source flux (possibly arising from Compton-thin material much closer to the black hole).
Pérez, F.; Kay, J. J.; Patterson, J. R.; Kane, J.; Villette, B.; Girard, F.; Reverdin, C.; May, M.; Emig, J.; Sorce, C.; Colvin, J.; Gammon, S.; Jaquez, J.; Satcher, J. H.; Fournier, K. B.
2012-08-01
The performance of new iron-based laser-driven x-ray sources has been tested at the OMEGA laser facility for production of x rays in the 6.5–8.5 keV range. Two types of targets were experimentally investigated: low-density iron oxide aerogels (density 6-16 mg/cm36-16 mg/cm3) and stainless steel foil-lined cavity targets (steel thickness 1-5 μm1-5 μm). The targets were irradiated by 40 beams of the OMEGA laser (500 J/beam, 1 ns pulse, wavelength 351 nm). All targets showed good coupling with the laser, with <5%<5% of the incident laser light backscattered by the resulting plasma in all cases (typically <2.5%<2.5%). The aerogel targets produced Te=2Te=2 to 3 keV, ne=0.12-0.2ne=0.12-0.2 critical density plasmas yielding a 40%–60% laser-to-x-ray total conversion efficiency (CE) (1.2%–3% in the Fe K-shell range). The foil cavity targets produced Te~2 keV, T_{e}~2 keV, n_{e}~0.15ne~0.15 critical density plasmas yielding a 60%–75% conversion efficiency (1.6%–2.2% in the Fe K-shell range). Time-resolved images illustrate that the volumetric heating of low-density aerogels allow them to emit a higher K-shell x-ray yield even though they contain fewer Fe atoms. However, their challenging fabrication process leads to a larger shot-to-shot variation than cavity targets.
Recurrence relation for relativistic atomic matrix elements
Martínez y Romero, R P; Salas-Brito, A L
2000-01-01
Recurrence formulae for arbitrary hydrogenic radial matrix elements are obtained in the Dirac form of relativistic quantum mechanics. Our approach is inspired on the relativistic extension of the second hypervirial method that has been succesfully employed to deduce an analogous relationship in non relativistic quantum mechanics. We obtain first the relativistic extension of the second hypervirial and then the relativistic recurrence relation. Furthermore, we use such relation to deduce relativistic versions of the Pasternack-Sternheimer rule and of the virial theorem.
Relativistic twins or sextuplets?
Sheldon, E S
2003-01-01
A recent study of the relativistic twin 'paradox' by Soni in this journal affirmed that 'A simple solution of the twin paradox also shows anomalous behaviour of rigidly connected distant clocks' but entailed a pedagogic hurdle which the present treatment aims to surmount. Two scenarios are presented: the first 'flight-plan' is akin to that depicted by Soni, with constant-velocity segments, while the second portrays an alternative mission undertaken with sustained acceleration and deceleration, illustrated quantitatively for a two-way spacecraft flight from Earth to Polaris (465.9 light years distant) and back.
Numerical Relativistic Quantum Optics
2013-11-08
µm and a = 1. The condition for an atomic spectrum to be non-relativistic is Z α−1 ≈ 137, as follows from elementary Dirac theory. One concludes that...peculiar result that B0 = 1 TG is a weak field. At present, such fields are observed only in connection with astrophysical phenomena [14]. The highest...pulsars. The Astrophysical Journal, 541:367–373, Sep 2000. [15] M. Tatarakis, I. Watts, F.N. Beg, E.L. Clark, A.E. Dangor, A. Gopal, M.G. Haines, P.A
Relativistic quantum information
Mann, R. B.; Ralph, T. C.
2012-11-01
Over the past few years, a new field of high research intensity has emerged that blends together concepts from gravitational physics and quantum computing. Known as relativistic quantum information, or RQI, the field aims to understand the relationship between special and general relativity and quantum information. Since the original discoveries of Hawking radiation and the Unruh effect, it has been known that incorporating the concepts of quantum theory into relativistic settings can produce new and surprising effects. However it is only in recent years that it has become appreciated that the basic concepts involved in quantum information science undergo significant revision in relativistic settings, and that new phenomena arise when quantum entanglement is combined with relativity. A number of examples illustrate that point. Quantum teleportation fidelity is affected between observers in uniform relative acceleration. Entanglement is an observer-dependent property that is degraded from the perspective of accelerated observers moving in flat spacetime. Entanglement can also be extracted from the vacuum of relativistic quantum field theories, and used to distinguish peculiar motion from cosmological expansion. The new quantum information-theoretic framework of quantum channels in terms of completely positive maps and operator algebras now provides powerful tools for studying matters of causality and information flow in quantum field theory in curved spacetimes. This focus issue provides a sample of the state of the art in research in RQI. Some of the articles in this issue review the subject while others provide interesting new results that will stimulate further research. What makes the subject all the more exciting is that it is beginning to enter the stage at which actual experiments can be contemplated, and some of the articles appearing in this issue discuss some of these exciting new developments. The subject of RQI pulls together concepts and ideas from
Corinaldesi, Ernesto
1963-01-01
Geared toward advanced undergraduate and graduate students of physics, this text provides readers with a background in relativistic wave mechanics and prepares them for the study of field theory. The treatment originated as a series of lectures from a course on advanced quantum mechanics that has been further amplified by student contributions.An introductory section related to particles and wave functions precedes the three-part treatment. An examination of particles of spin zero follows, addressing wave equation, Lagrangian formalism, physical quantities as mean values, translation and rotat
Rössler, O E; Matsuno, K
1998-04-01
The two mindsets of absolutism and relativism are juxtaposed, and the relational or relativist stance is vindicated. The only 'absolute' entity which undeniably exists, consciousness has the reality of a dream. The escape hatch from this prison is relational, as Descartes and Levinas found out: Unfalsified relational consistency implies exteriority. Exteriority implies infinite power which in turn makes compassion inevitable. Aside from ethics as a royal way to enlightenment, a new technology called 'deep technology' may be accessible. It changes the whole world in a demonstrable fashion by manipulation of the micro frame--that is, the observer-world interface.
Dopita, Michael A; Sutherland, Ralph S; Vogt, Frédéric P A; Winkler, P Frank; Blair, William P
2016-01-01
We present results of a complete integral field survey of the bright SNR N49 in the LMC, obtained with the WiFeS instrument mounted on the ANU 2.3m telescope at Siding Spring Observatory. From theoretical shock modelling with the new MAPPINGS 5.1 code we have, for the first time, subjected the optical Fe emission line spectrum of a supernova remnant to a detailed abundance and dynamical analysis covering 8 separate stages of ionisation. This allows us to derive the dust depletion factors as a function of ionisation stage. We have shown that there is substantial (30% - 90%) destruction of Fe-bearing dust grains in these fast shocks ($v_s \\sim 250$ km/s), and we have confirmed that the dominant dust destruction is through the non-thermal sputtering and grain-grain collision mechanisms developed in a number of theoretical works.
Dopita, Michael A.; Seitenzahl, Ivo R.; Sutherland, Ralph S.; Vogt, Frédéric P. A.; Winkler, P. Frank; Blair, William P.
2016-08-01
We present the results of a complete integral-field survey of the bright supernova remnant (SNR) N49 in the Large Magellanic Cloud, obtained with the WiFeS instrument mounted on the ANU 2.3 m telescope at Siding Spring Observatory. From theoretical shock modeling with the new MAPPINGS 5.1 code, we have, for the first time, subjected the optical Fe emission line spectrum of an SNR to a detailed abundance and dynamical analysis covering eight separate stages of ionization. This allows us to derive the dust depletion factors as a function of ionization stage. We have shown that there is substantial (30%-90%) destruction of Fe-bearing dust grains in these fast shocks (v s ˜ 250 km s-1), and we have confirmed that the dominant dust destruction occurs through the non-thermal sputtering and grain-grain collision mechanisms developed in a number of theoretical works.
Exotic Non-relativistic String
Casalbuoni, Roberto; Longhi, Giorgio
2007-01-01
We construct a classical non-relativistic string model in 3+1 dimensions. The model contains a spurion tensor field that is responsible for the non-commutative structure of the model. Under double dimensional reduction the model reduces to the exotic non-relativistic particle in 2+1 dimensions.
'Antigravity' Propulsion and Relativistic Hyperdrive
Felber, F S
2006-01-01
Exact payload trajectories in the strong gravitational fields of compact masses moving with constant relativistic velocities are calculated. The strong field of a suitable driver mass at relativistic speeds can quickly propel a heavy payload from rest to a speed significantly faster than the driver, a condition called hyperdrive. Hyperdrive thresholds and maxima are calculated as functions of driver mass and velocity.
A Simple Relativistic Bohr Atom
Terzis, Andreas F.
2008-01-01
A simple concise relativistic modification of the standard Bohr model for hydrogen-like atoms with circular orbits is presented. As the derivation requires basic knowledge of classical and relativistic mechanics, it can be taught in standard courses in modern physics and introductory quantum mechanics. In addition, it can be shown in a class that…
A Simple Relativistic Bohr Atom
Terzis, Andreas F.
2008-01-01
A simple concise relativistic modification of the standard Bohr model for hydrogen-like atoms with circular orbits is presented. As the derivation requires basic knowledge of classical and relativistic mechanics, it can be taught in standard courses in modern physics and introductory quantum mechanics. In addition, it can be shown in a class that…
Barbaro, Daniele; Di Bari, Lorenzo; Gandin, Valentina; Evangelisti, Claudio; Vitulli, Giovanni; Schiavi, Eleonora; Marzano, Cristina; Ferretti, Anna M; Salvadori, Piero
2015-01-01
Iron oxide nanoparticles (IONP) can have a variety of biomedical applications due to their visualization properties through Magnetic Resonance Imaging (MRI) and heating with radio frequency or alternating magnetic fields. In the oncological field, coating IONP with organic compounds to provide specific features and to achieve the ability of binding specific molecular targets appears to be very promising. To take advantage of the high avidity of tumor cells for glucose, we report the development of very small glucose-coated IONP (glc-IONP) by employing an innovative technique, Metal Vapor Synthesis (MVS). Moreover, we tested the internalization of our gl-IONP on a tumor line, BxPC3, over-expressing GLUT 1 transporter. Both glc-IONP and polyvinylpyrrolidone-IONP (PVP-IONP), as control, were prepared with MVS and were tested on BxPC3 at various concentrations. To evaluate the role of GLUT-1 transporter, we also investigated the effect of adding a polyclonal anti-GLUT1 antibody. After proper treatment, the iron value was assessed by atomic absorption spectrometer, reported in mcg/L and expressed in mg of protein. Our IONP prepared with MVS were very small and homogeneously distributed in a narrow range (1.75-3.75 nm) with an average size of 2.7 nm and were super-paramagnetic. Glc-IONP were internalized by BxPC3 cells in a larger amount than PVP-IONP. After 6h of treatment with 50 mcg/mL of IONPs, the content of Fe was 1.5 times higher in glc-IONP-treated cells compared with PVP-IONP-treated cells. After 1h pre-treatment with anti-GLUT1, a reduction of 41% cellular accumulation of glc-IONP was observed. Conversely, the uptake of PVP-IONPs was reduced only by 14% with antibody pretreatment. In conclusion, MVS allowed us to prepare small, homogeneous, super-paramagnetic glc-IONP, which are electively internalized by a tumor line over-expressing GLUT1. Our glc-IONP appear to have many requisites for in vivo use.
Daniele Barbaro
Full Text Available Iron oxide nanoparticles (IONP can have a variety of biomedical applications due to their visualization properties through Magnetic Resonance Imaging (MRI and heating with radio frequency or alternating magnetic fields. In the oncological field, coating IONP with organic compounds to provide specific features and to achieve the ability of binding specific molecular targets appears to be very promising. To take advantage of the high avidity of tumor cells for glucose, we report the development of very small glucose-coated IONP (glc-IONP by employing an innovative technique, Metal Vapor Synthesis (MVS. Moreover, we tested the internalization of our gl-IONP on a tumor line, BxPC3, over-expressing GLUT 1 transporter. Both glc-IONP and polyvinylpyrrolidone-IONP (PVP-IONP, as control, were prepared with MVS and were tested on BxPC3 at various concentrations. To evaluate the role of GLUT-1 transporter, we also investigated the effect of adding a polyclonal anti-GLUT1 antibody. After proper treatment, the iron value was assessed by atomic absorption spectrometer, reported in mcg/L and expressed in mg of protein. Our IONP prepared with MVS were very small and homogeneously distributed in a narrow range (1.75-3.75 nm with an average size of 2.7 nm and were super-paramagnetic. Glc-IONP were internalized by BxPC3 cells in a larger amount than PVP-IONP. After 6h of treatment with 50 mcg/mL of IONPs, the content of Fe was 1.5 times higher in glc-IONP-treated cells compared with PVP-IONP-treated cells. After 1h pre-treatment with anti-GLUT1, a reduction of 41% cellular accumulation of glc-IONP was observed. Conversely, the uptake of PVP-IONPs was reduced only by 14% with antibody pretreatment. In conclusion, MVS allowed us to prepare small, homogeneous, super-paramagnetic glc-IONP, which are electively internalized by a tumor line over-expressing GLUT1. Our glc-IONP appear to have many requisites for in vivo use.
Komissarov, S S; Lyutikov, M
2015-01-01
In this paper we describe a simple numerical approach which allows to study the structure of steady-state axisymmetric relativistic jets using one-dimensional time-dependent simulations. It is based on the fact that for narrow jets with v~c the steady-state equations of relativistic magnetohydrodynamics can be accurately approximated by the one-dimensional time-dependent equations after the substitution z=ct. Since only the time-dependent codes are now publicly available this is a valuable and efficient alternative to the development of a high-specialized code for the time-independent equations. The approach is also much cheaper and more robust compared to the relaxation method. We tested this technique against numerical and analytical solutions found in literature as well as solutions we obtained using the relaxation method and found it sufficiently accurate. In the process, we discovered the reason for the failure of the self-similar analytical model of the jet reconfinement in relatively flat atmospheres a...
Robust relativistic bit commitment
Chakraborty, Kaushik; Chailloux, André; Leverrier, Anthony
2016-12-01
Relativistic cryptography exploits the fact that no information can travel faster than the speed of light in order to obtain security guarantees that cannot be achieved from the laws of quantum mechanics alone. Recently, Lunghi et al. [Phys. Rev. Lett. 115, 030502 (2015), 10.1103/PhysRevLett.115.030502] presented a bit-commitment scheme where each party uses two agents that exchange classical information in a synchronized fashion, and that is both hiding and binding. A caveat is that the commitment time is intrinsically limited by the spatial configuration of the players, and increasing this time requires the agents to exchange messages during the whole duration of the protocol. While such a solution remains computationally attractive, its practicality is severely limited in realistic settings since all communication must remain perfectly synchronized at all times. In this work, we introduce a robust protocol for relativistic bit commitment that tolerates failures of the classical communication network. This is done by adding a third agent to both parties. Our scheme provides a quadratic improvement in terms of expected sustain time compared with the original protocol, while retaining the same level of security.
A relativistic trolley paradox
Matvejev, Vadim N.; Matvejev, Oleg V.; Grøn, Ø.
2016-06-01
We present an apparent paradox within the special theory of relativity, involving a trolley with relativistic velocity and its rolling wheels. Two solutions are given, both making clear the physical reality of the Lorentz contraction, and that the distance on the rails between each time a specific point on the rim touches the rail is not equal to 2 π R , where R is the radius of the wheel, but 2 π R / √{ 1 - R 2 Ω 2 / c 2 } , where Ω is the angular velocity of the wheels. In one solution, the wheel radius is constant as the velocity of the trolley increases, and in the other the wheels contract in the radial direction. We also explain two surprising facts. First that the shape of a rolling wheel is elliptical in spite of the fact that the upper part of the wheel moves faster than the lower part, and thus is more Lorentz contracted, and second that a Lorentz contracted wheel with relativistic velocity rolls out a larger distance between two successive touches of a point of the wheel on the rails than the length of a circle with the same radius as the wheels.
Fractional Dynamics of Relativistic Particle
Tarasov, Vasily E
2011-01-01
Fractional dynamics of relativistic particle is discussed. Derivatives of fractional orders with respect to proper time describe long-term memory effects that correspond to intrinsic dissipative processes. Relativistic particle subjected to a non-potential four-force is considered as a nonholonomic system. The nonholonomic constraint in four-dimensional space-time represents the relativistic invariance by the equation for four-velocity u_{\\mu} u^{\\mu}+c^2=0, where c is a speed of light in vacuum. In the general case, the fractional dynamics of relativistic particle is described as non-Hamiltonian and dissipative. Conditions for fractional relativistic particle to be a Hamiltonian system are considered.
Formation of relativistic jets. Magnetohydrodynamics and synchrotron radiation
Porth, Oliver Joachim Georg
2011-11-09
In this thesis, the formation of relativistic jets is investigated by means of special relativistic magnetohydrodynamic simulations and synchrotron radiative transfer. Our results show that the magnetohydrodynamic jet self-collimation paradigm can also be applied to the relativistic case. In the first part, jets launched from rotating hot accretion disk coronae are explored, leading to well collimated, but only mildly relativistic flows. Beyond the light-cylinder, the electric charge separation force balances the classical trans-field Lorentz force almost entirely, resulting in a decreased efficiency of acceleration and collimation in comparison to non-relativistic disk winds. In the second part, we examine Poynting dominated flows of various electric current distributions. By following the outflow for over 3000 Schwarzschild radii, highly relativistic jets of Lorentz factor Γ>or similar 8 and half-opening angles below 1 are obtained, providing dynamical models for the parsec scale jets of active galactic nuclei. Applying the magnetohydrodynamic structure of the quasi-stationary simulation models, we solve the relativistically beamed synchrotron radiation transport. This yields synthetic radiation maps and polarization patterns that can be used to confront high resolution radio and (sub-) mm observations of nearby active galactic nuclei. Relativistic motion together with the helical magnetic fields of the jet formation site imprint a clear signature on the observed polarization and Faraday rotation. In particular, asymmetries in the polarization direction across the jet can disclose the handedness of the magnetic helix and thus the spin direction of the central engine. Finally, we show first results from fully three-dimensional, high resolution adaptive mesh refinement simulations of jet formation from a rotating magnetosphere and examine the jet stability. Relativistic field-line rotation leads to an electric charge separation force that opposes the magnetic
Dongbo Lin; Chunli Chen; Guangyuaa Hu; Qi Mei; Hong Qiu; Guoxian Long; Guoqing Hu
2011-01-01
An accurate definition of clinical target volume (CTV) is essential for the application of radiotherapy in nasopharvngeai carcinoma (NPC) treatment. A novel epidermal growth factor receptor (EGFR)-targeting contrast agent (C225-USPIO) was designed by conjugating ultrasmail superparamagnetic iron oxide (USPIO) nanoparticles with cetuximab (C225), to non-invasively define the CTV of tumor. The immunobinding activity of C225-USPIO to NPC cell line CNEI was confirmed by flow cytometry and immunofluorescence. The time-dependent accumulation of C225-USPIO in CNE1 cells was evaluated using Prussian blue staining. Targeted internalization and subcellular localization of C225-USPIO was confirmed by transmission electron microscope. The results indicated that C225-USPIO specifically bound to EGFR on the surface of CNEI cells and was taken up into the cell. The uptake of C225-USPIO by CNE1 cells increased significantly with time, when compared with human IgG-USPIO. In addition, 4.7 T magnetic resonance imaging (MRI) revealed that C225-USPIO had a capacity to accumulate in the CNE1 cells, with a resultant marked decrease in MRI T2-weighted signal intensity over time. These findings imply that C225-USPIO has the potential as an MRI contrast agent and can be employed to non-invasively detect early-stage NPC with EGFR overexpression. This provides sufficient theoretical basis for commencing in vivo experiments with the compound.
Magnetic Dissipation in Relativistic Jets
Yosuke Mizuno
2016-10-01
Full Text Available The most promising mechanisms for producing and accelerating relativistic jets, and maintaining collimated structure of relativistic jets involve magnetohydrodynamical (MHD processes. We have investigated the magnetic dissipation mechanism in relativistic jets via relativistic MHD simulations. We found that the relativistic jets involving a helical magnetic field are unstable for the current-driven kink instability, which leads to helically distorted structure in relativistic jets. We identified the regions of high current density in filamentary current sheets, indicative of magnetic reconnection, which are associated to the kink unstable regions and correlated to the converted regions of magnetic to kinetic energies of the jets. We also found that an over-pressured relativistic jet leads to the generation of a series of stationary recollimation shocks and rarefaction structures by the nonlinear interaction of shocks and rarefaction waves. The differences in the recollimation shock structure due to the difference of the magnetic field topologies and strengths may be observable through mm-VLBI observations and space-VLBI mission.
Relativistic Fractal Cosmologies
Ribeiro, Marcelo B
2009-01-01
This article reviews an approach for constructing a simple relativistic fractal cosmology whose main aim is to model the observed inhomogeneities of the distribution of galaxies by means of the Lemaitre-Tolman solution of Einstein's field equations for spherically symmetric dust in comoving coordinates. This model is based on earlier works developed by L. Pietronero and J.R. Wertz on Newtonian cosmology, whose main points are discussed. Observational relations in this spacetime are presented, together with a strategy for finding numerical solutions which approximate an averaged and smoothed out single fractal structure in the past light cone. Such fractal solutions are shown, with one of them being in agreement with some basic observational constraints, including the decay of the average density with the distance as a power law (the de Vaucouleurs' density power law) and the fractal dimension in the range 1 <= D <= 2. The spatially homogeneous Friedmann model is discussed as a special case of the Lemait...
Relativistic Gravothermal Instabilities
Roupas, Zacharias
2014-01-01
The thermodynamic instabilities of the self-gravitating, classical ideal gas are studied in the case of static, spherically symmetric configurations in General Relativity taking into account the Tolman-Ehrenfest effect. One type of instabilities is found at low energies, where thermal energy becomes too weak to halt gravity and another at high energies, where gravitational attraction of thermal pressure overcomes its stabilizing effect. These turning points of stability are found to depend on the total rest mass $\\mathcal{M}$ over the radius $R$. The low energy instability is the relativistic generalization of Antonov instability, which is recovered in the limit $G\\mathcal{M} \\ll R c^2$ and low temperatures, while in the same limit and high temperatures, the high energy instability recovers the instability of the radiation equation of state. In the temperature versus energy diagram of series of equilibria, the two types of gravothermal instabilities make themselves evident as a double spiral! The two energy l...
Lock, Maximilian P E
2016-01-01
The conflict between quantum theory and the theory of relativity is exemplified in their treatment of time. We examine the ways in which their conceptions differ, and describe a semiclassical clock model combining elements of both theories. The results obtained with this clock model in flat spacetime are reviewed, and the problem of generalizing the model to curved spacetime is discussed, before briefly describing an experimental setup which could be used to test of the model. Taking an operationalist view, where time is that which is measured by a clock, we discuss the conclusions that can be drawn from these results, and what clues they contain for a full quantum relativistic theory of time.
Galilean relativistic fluid mechanics
Ván, Péter
2015-01-01
Single component Galilean-relativistic (nonrelativistic) fluids are treated independently of reference frames. The basic fields are given, their balances, thermodynamic relations and the entropy production is calculated. The usual relative basic fields, the mass, momentum and energy densities, the diffusion current density, the pressure tensor and the heat flux are the time- and spacelike components of the third order mass-momentum-energy density tensor according to a velocity field. The transformation rules of the basic fields are derived and prove that the non-equilibrium thermodynamic background theory, that is the Gibbs relation, extensivity condition and the entropy production is absolute, that is independent of the reference frame and also of the fluid velocity. --- Az egykomponensu Galilei-relativisztikus (azaz nemrelativisztikus) disszipativ folyadekokat vonatkoztatasi rendszertol fuggetlenul targyaljuk. Megadjuk az alapmennyisegeket, ezek merlegeit, a termodinamikai osszefuggeseket es kiszamoljuk az ...
Colin Correnti
Full Text Available Siderocalin (also lipocalin 2, NGAL or 24p3 binds iron as complexes with specific siderophores, which are low molecular weight, ferric ion-specific chelators. In innate immunity, siderocalin slows the growth of infecting bacteria by sequestering bacterial ferric siderophores. Siderocalin also binds simple catechols, which can serve as siderophores in the damaged urinary tract. Siderocalin has also been proposed to alter cellular iron trafficking, for instance, driving apoptosis through iron efflux via BOCT. An endogenous siderophore composed of gentisic acid (2,5-dihydroxybenzoic acid substituents was proposed to mediate cellular efflux. However, binding studies reported herein contradict the proposal that gentisic acid forms high-affinity ternary complexes with siderocalin and iron, or that gentisic acid can serve as an endogenous siderophore at neutral pH. We also demonstrate that siderocalin does not induce cellular iron efflux or stimulate apoptosis, questioning the role siderocalin plays in modulating iron metabolism.
Relativistic Runaway Electrons
Breizman, Boris
2014-10-01
This talk covers recent developments in the theory of runaway electrons in a tokamak with an emphasis on highly relativistic electrons produced via the avalanche mechanism. The rapidly growing population of runaway electrons can quickly replace a large part of the initial current carried by the bulk plasma electrons. The magnetic energy associated with this current is typically much greater than the particle kinetic energy. The current of a highly relativistic runaway beam is insensitive to the particle energy, which separates the description of the runaway current evolution from the description of the runaway energy spectrum. A strongly anisotropic distribution of fast electrons is generally prone to high-frequency kinetic instabilities that may cause beneficial enhancement of runaway energy losses. The relevant instabilities are in the frequency range of whistler waves and electron plasma waves. The instability thresholds reported in earlier work have been revised considerably to reflect strong dependence of collisional damping on the wave frequency and the role of plasma non-uniformity, including radial trapping of the excited waves in the plasma. The talk also includes a discussion of enhanced scattering of the runaways as well as the combined effect of enhanced scattering and synchrotron radiation. A noteworthy feature of the avalanche-produced runaway current is a self-sustained regime of marginal criticality: the inductive electric field has to be close to its critical value (representing avalanche threshold) at every location where the runaway current density is finite, and the current density should vanish at any point where the electric field drops below its critical value. This nonlinear Ohm's law enables complete description of the evolving current profile. Work supported by the U.S. Department of Energy Contract No. DEFG02-04ER54742 and by ITER contract ITER-CT-12-4300000273. The views and opinions expressed herein do not necessarily reflect those of
Iron and iron derived radicals
Borg, D.C.; Schaich, K.M.
1987-04-01
We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fastexclamation Think smallexclamation In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab.
What is "Relativistic Canonical Quantization"?
Arbatsky, D. A.
2005-01-01
The purpose of this review is to give the most popular description of the scheme of quantization of relativistic fields that was named relativistic canonical quantization (RCQ). I do not give here the full exact account of this scheme. But with the help of this review any physicist, even not a specialist in the relativistic quantum theory, will be able to get a general view of the content of RCQ, of its connection with other known approaches, of its novelty and of its fruitfulness.
Mitigating the hosing instability in relativistic laser-plasma interactions
Ceurvorst, L.; Ratan, N.; Levy, M. C.; Kasim, M. F.; Sadler, J.; Scott, R. H. H.; Trines, R. M. G. M.; Huang, T. W.; Skramic, M.; Vranic, M.; Silva, L. O.; Norreys, P. A.
2016-05-01
A new physical model of the hosing instability that includes relativistic laser pulses and moderate densities is presented and derives the density dependence of the hosing equation. This is tested against two-dimensional particle-in-cell simulations. These simulations further examine the feasibility of using multiple pulses to mitigate the hosing instability in a Nd:glass-type parameter space. An examination of the effects of planar versus cylindrical exponential density gradients on the hosing instability is also presented. The results show that strongly relativistic pulses and more planar geometries are capable of mitigating the hosing instability which is in line with the predictions of the physical model.
Simulating relativistic binaries with Whisky
Baiotti, L.
We report about our first tests and results in simulating the last phase of the coalescence and the merger of binary relativistic stars. The simulations were performed using our code Whisky and mesh refinement through the Carpet driver.
Relativistic effects in atom gravimeters
Tan, Yu-Jie; Shao, Cheng-Gang; Hu, Zhong-Kun
2017-01-01
Atom interferometry is currently developing rapidly, which is now reaching sufficient precision to motivate laboratory tests of general relativity. Thus, it is extremely significant to develop a general relativistic model for atom interferometers. In this paper, we mainly present an analytical derivation process and first give a complete vectorial expression for the relativistic interferometric phase shift in an atom interferometer. The dynamics of the interferometer are studied, where both the atoms and the light are treated relativistically. Then, an appropriate coordinate transformation for the light is performed crucially to simplify the calculation. In addition, the Bordé A B C D matrix combined with quantum mechanics and the "perturbation" approach are applied to make a methodical calculation for the total phase shift. Finally, we derive the relativistic phase shift kept up to a sensitivity of the acceleration ˜1 0-14 m/s 2 for a 10 -m -long atom interferometer.
Lopez, Anthony; Cacoub, Patrice; Macdougall, Iain C; Peyrin-Biroulet, Laurent
2016-02-27
Anaemia affects roughly a third of the world's population; half the cases are due to iron deficiency. It is a major and global public health problem that affects maternal and child mortality, physical performance, and referral to health-care professionals. Children aged 0-5 years, women of childbearing age, and pregnant women are particularly at risk. Several chronic diseases are frequently associated with iron deficiency anaemia--notably chronic kidney disease, chronic heart failure, cancer, and inflammatory bowel disease. Measurement of serum ferritin, transferrin saturation, serum soluble transferrin receptors, and the serum soluble transferrin receptors-ferritin index are more accurate than classic red cell indices in the diagnosis of iron deficiency anaemia. In addition to the search for and treatment of the cause of iron deficiency, treatment strategies encompass prevention, including food fortification and iron supplementation. Oral iron is usually recommended as first-line therapy, but the most recent intravenous iron formulations, which have been available for nearly a decade, seem to replenish iron stores safely and effectively. Hepcidin has a key role in iron homoeostasis and could be a future diagnostic and therapeutic target. In this Seminar, we discuss the clinical presentation, epidemiology, pathophysiology, diagnosis, and acute management of iron deficiency anaemia, and outstanding research questions for treatment.
Emission vs Fermi coordinates: applications to relativistic positioning systems
Bini, Donato; Ruggiero, Matteo Luca; Tartaglia, Angelo
2008-01-01
A 4-dimensional relativistic positioning system for a general spacetime is constructed by using the so called "emission coordinates". The results apply in a small region around the world line of an accelerated observer carrying a Fermi triad, as described by the Fermi metric. In the case of a Schwarzschild spacetime modeling the gravitational field around the Earth and an observer at rest at a fixed spacetime point, these coordinates realize a relativistic positioning system alternative to the current GPS system. The latter is indeed essentially conceived as Newtonian, so that it necessarily needs taking into account at least the most important relativistic effects through Post-Newtonian corrections to work properly. Previous results concerning emission coordinates in flat spacetime are thus extended to this more general situation. Furthermore, the mapping between spacetime coordinates and emission coordinates is completely determined by means of the world function, which in the case of a Fermi metric can be ...
Relativistic corrections to prompt J/ψ photo- and hadroproduction
He, Zhi-Guo; Kniehl, Bernd A.
2014-07-01
We systematically calculate the relativistic corrections to prompt J/ψ photoproduction and hadroproduction using the factorization formalism of nonrelativistic QCD. Specifically, we include the S31[1] and P3J[1] color-singlet and the S31[8], S10[8], and P3J[8] color-octet channels as well as the effects due to the mixing between the S31[8] and D31[8] channels. We provide all the squared hard-scattering amplitudes in analytic form. Assuming the nonrelativistic-QCD long-distance matrix elements to satisfy the velocity scaling rules, we find the relativistic corrections to be appreciable, except in the S31[1] color-singlet channel of hadroproduction. We also observe significant differences in the line shapes of the relativistic corrections between photoproduction and hadroproduction.
Scattering in Relativistic Particle Mechanics.
de Bievre, Stephan
The problem of direct interaction in relativistic particle mechanics has been extensively studied and a variety of models has been proposed avoiding the conclusions of the so-called no-interaction theorems. In this thesis we study scattering in the relativistic two-body problem. We use our results to analyse gauge invariance in Hamiltonian constraint models and the uniqueness of the symplectic structure in manifestly covariant relativistic particle mechanics. We first present a general geometric framework that underlies approaches to relativistic particle mechanics. This permits a model-independent and geometric definition of the notions of asymptotic completeness and of Moller and scattering operators. Subsequent analysis of these concepts divides into two parts. First, we study the kinematic properties of the scattering transformation, i.e. those properties that arise solely from the invariance of the theory under the Poincare group. We classify all canonical (symplectic) scattering transformations on the relativistic phase space for two free particles in terms of a single function of the two invariants of the theory. We show how this function is determined by the center of mass time delay and scattering angle and vice versa. The second part of our analysis of the relativistic two-body scattering problem is devoted to the dynamical properties of the scattering process. Hence, we turn to two approaches to relativistic particle mechanics: the Hamiltonian constraint models and the manifestly covariant formalism. Using general geometric arguments, we prove "gauge invariance" of the scattering transformation in the Todorov -Komar Hamiltonian constraint model. We conclude that the scattering cross sections of the Todorov-Komar models have the same angular dependence as their non-relativistic counterpart, irrespective of a choice of gauge. This limits the physical relevance of those models. We present a physically non -trivial Hamiltonian constraint model, starting from
Soliton propagation in relativistic hydrodynamics
Fogaça, D A; 10.1016/j.nuclphysa.2007.03.104
2013-01-01
We study the conditions for the formation and propagation of Korteweg-de Vries (KdV) solitons in nuclear matter. In a previous work we have derived a KdV equation from Euler and continuity equations in non-relativistic hydrodynamics. In the present contribution we extend our formalism to relativistic fluids. We present results for a given equation of state, which is based on quantum hadrodynamics (QHD).
Relativistic formulation and reference frame
Klioner, Sergei A.
2004-01-01
After a short review of experimental foundations of metric theories of gravity, the choice of general relativity as a theory to be used for the routine modeling of Gaia observations is justified. General principles of relativistic modeling of astronomical observations are then sketched and compared to the corresponding Newtonian principles. The fundamental reference system -- Barycentric Celestial Reference System, which has been chosen to be the relativistic reference system underlying the f...
Fuerst, Steven V.; /KIPAC, Menlo Park; Mizuno, Yosuke; /USRA, Huntsville; Nishikawa, Ken-Ichi; /USRA, Huntsville /Alabama U., Huntsville; Wu, Kinwah; /Mullard Space Sci.
2007-01-05
We calculate the emission from relativistic flows in black hole systems using a fully general relativistic radiative transfer formulation, with flow structures obtained by general relativistic magneto-hydrodynamic simulations. We consider thermal free-free emission and thermal synchrotron emission. Bright filament-like features protrude (visually) from the accretion disk surface, which are enhancements of synchrotron emission where the magnetic field roughly aligns with the line-of-sight in the co-moving frame. The features move back and forth as the accretion flow evolves, but their visibility and morphology are robust. We propose that variations and drifts of the features produce certain X-ray quasi-periodic oscillations (QPOs) observed in black-hole X-ray binaries.
Non-relativistic twistor theory and Newton--Cartan geometry
Dunajski, Maciej
2015-01-01
We develop a non-relativistic twistor theory, in which Newton--Cartan structures of Newtonian gravity correspond to complex three-manifolds with a four-parameter family of rational curves with normal bundle ${\\mathcal O}\\oplus{\\mathcal O}(2)$. We show that the Newton--Cartan space-times are unstable under the general Kodaira deformation of the twistor complex structure. The Newton--Cartan connections can nevertheless be reconstructed from Merkulov's generalisation of the Kodaira map augmented by a choice of a holomorphic line bundle over the twistor space trivial on twistor lines. The Coriolis force may be incorporated by holomorphic vector bundles, which in general are non--trivial on twistor lines. The resulting geometries agree with non--relativistic limits of anti-self-dual gravitational instantons.
... as: Serum Iron; Serum Fe Formal name: Iron, serum Related tests: Ferritin ; TIBC, UIBC and Transferrin ; Hemoglobin ; Hematocrit ; Complete Blood Count ; Reticulocyte Count ; Zinc Protoporphyrin ; Iron Tests ; Soluble Transferrin Receptor ... I should know? How is it used? Serum iron, total iron-binding capacity (TIBC) , and/or ...
2012-01-01
We have engineered the starchy root crop cassava (Manihot esculenta) to express the Chlamydomonas reinhardtii iron assimilatory protein, FEA1, in roots to enhance its nutritional qualities. Iron levels in mature cassava storage roots were increased from 10 to 36 ppm in the highest iron accumulating transgenic lines. These iron levels are sufficient to meet the minimum daily requirement for iron in a 500 gm meal. Significantly, the expression of the FEA1 protein did not alter iron levels in l...
Refining a relativistic, hydrodynamic solver: Admitting ultra-relativistic flows
Bernstein, J. P.; Hughes, P. A.
2009-09-01
We have undertaken the simulation of hydrodynamic flows with bulk Lorentz factors in the range 102-106. We discuss the application of an existing relativistic, hydrodynamic primitive variable recovery algorithm to a study of pulsar winds, and, in particular, the refinement made to admit such ultra-relativistic flows. We show that an iterative quartic root finder breaks down for Lorentz factors above 102 and employ an analytic root finder as a solution. We find that the former, which is known to be robust for Lorentz factors up to at least 50, offers a 24% speed advantage. We demonstrate the existence of a simple diagnostic allowing for a hybrid primitives recovery algorithm that includes an automatic, real-time toggle between the iterative and analytical methods. We further determine the accuracy of the iterative and hybrid algorithms for a comprehensive selection of input parameters and demonstrate the latter’s capability to elucidate the internal structure of ultra-relativistic plasmas. In particular, we discuss simulations showing that the interaction of a light, ultra-relativistic pulsar wind with a slow, dense ambient medium can give rise to asymmetry reminiscent of the Guitar nebula leading to the formation of a relativistic backflow harboring a series of internal shockwaves. The shockwaves provide thermalized energy that is available for the continued inflation of the PWN bubble. In turn, the bubble enhances the asymmetry, thereby providing positive feedback to the backflow.
[Iron deficiency and iron deficiency anemia are global health problems].
Dahlerup, Jens; Lindgren, Stefan; Moum, Björn
2015-03-10
Iron deficiency and iron deficiency anemia are global health problems leading to deterioration in patients' quality of life and more serious prognosis in patients with chronic diseases. The cause of iron deficiency and anemia is usually a combination of increased loss and decreased intestinal absorption and delivery from iron stores due to inflammation. Oral iron is first line treatment, but often hampered by intolerance. Intravenous iron is safe, and the preferred treatment in patients with chronic inflammation and bowel diseases. The goal of treatment is normalisation of hemoglobin concentration and recovery of iron stores. It is important to follow up treatment to ensure that these objectives are met and also long-term in patients with chronic iron loss and/or inflammation to avoid recurrence of anemia.
Hajikarimi, Zahra; Khoei, Samideh; Khoee, Sepideh; Mahdavi, Seied Rabi
2014-12-01
The purpose of this study was to investigate the uptake and cytotoxic effects of magnetic poly lactic-co-glycolic acid (PLGA)-coated iron oxide nanoparticles as a carrier of 5-fluorouracil (5-FU) and X-ray on the level of proliferation capacity of DU145 prostate carcinoma cell line in monolayer culture. Following monolayer culture, DU 145 cells were treated with different concentrations of 5-FU or 5-FU loaded nanoparticles for 24 h and 2Gy X-ray (6 Mega-voltage (MV)). The rate of nanoparticles penetration was then measured using atomic adsorption spectroscopy (AAS). The cytotoxicity effect of these nanoparticles with/ without X-ray radiation was evaluated using colony formation assay. Spectroscopy results showed that iron content and therefore the cellular uptake of 5-FU loaded nanoparticles increased with increasing nanoparticle concentrations. Further, the proliferation capacity of the cells decreased with the increase of 5-FU and 5- FU loaded nanoparticle concentrations in combination with X-ray radiation. However the extent of reduction in colony number following treatment with 5-FU-loaded nanoparticles in combination with 2Gy of megavoltage X-ray radiation was significantly more than for free 5-FU. Thus, drug-loaded nanoparticles could deliver 5-FU more efficiently into the cells. PLGA coated iron oxide nanoparticles are therefore effective drug delivery vehicles for 5-FU. PLGA coated iron oxide nanoparticles are biocompatible and this coating is an appropriate surface that can penetrate into the cells.
Empirical Foundations of Relativistic Gravity
Ni, W T
2005-01-01
In 1859, Le Verrier discovered the mercury perihelion advance anomaly. This anomaly turned out to be the first relativistic-gravity effect observed. During the 141 years to 2000, the precisions of laboratory and space experiments, and astrophysical and cosmological observations on relativistic gravity have been improved by 3 orders of magnitude. In 1999, we envisaged a 3-6 order improvement in the next 30 years in all directions of tests of relativistic gravity. In 2000, the interferometric gravitational wave detectors began their runs to accumulate data. In 2003, the measurement of relativistic Shapiro time-delay of the Cassini spacecraft determined the relativistic-gravity parameter gammaγ with a 1.5-order improvement. In October 2004, Ciufolini and Pavlis reported a measurement of the Lense-Thirring effect on the LAGEOS and LAGEOS2 satellites to 10 percent of the value predicted by general relativity. In April 2004, Gravity Probe B was launched and has been accumulating science data for more than ...
Relativistic Lagrangians for the Lorentz–Dirac equation
Deguchi, Shinichi, E-mail: deguchi@phys.cst.nihon-u.ac.jp [Institute of Quantum Science, College of Science and Technology, Nihon University, Chiyoda-ku, Tokyo 101-8308 (Japan); Nakano, Kunihiko [Institute of Quantum Science, College of Science and Technology, Nihon University, Chiyoda-ku, Tokyo 101-8308 (Japan); Suzuki, Takafumi [Junior College Funabashi Campus, Nihon University, Narashinodai, Funabashi, Chiba 274-8501 (Japan)
2015-09-15
We present two types of relativistic Lagrangians for the Lorentz–Dirac equation written in terms of an arbitrary world-line parameter. One of the Lagrangians contains an exponential damping function of the proper time and explicitly depends on the world-line parameter. Another Lagrangian includes additional cross-terms consisting of auxiliary dynamical variables and does not depend explicitly on the world-line parameter. We demonstrate that both the Lagrangians actually yield the Lorentz–Dirac equation with a source-like term.
Relativistic causality and clockless circuits
Matherat, Philippe; 10.1145/2043643.2043650
2011-01-01
Time plays a crucial role in the performance of computing systems. The accurate modelling of logical devices, and of their physical implementations, requires an appropriate representation of time and of all properties that depend on this notion. The need for a proper model, particularly acute in the design of clockless delay-insensitive (DI) circuits, leads one to reconsider the classical descriptions of time and of the resulting order and causal relations satisfied by logical operations. This questioning meets the criticisms of classical spacetime formulated by Einstein when founding relativity theory and is answered by relativistic conceptions of time and causality. Applying this approach to clockless circuits and considering the trace formalism, we rewrite Udding's rules which characterize communications between DI components. We exhibit their intrinsic relation with relativistic causality. For that purpose, we introduce relativistic generalizations of traces, called R-traces, which provide a pertinent des...
朱焕立; 刘许亮
2014-01-01
根据凸轮轴的工艺和生产特点,成功设计出凸轮轴铁型覆砂铸造自动化生产线,提高了凸轮轴的生产效率,同时实现高产能、低排放,并为铁型覆砂铸造技术的推广应用奠定了基础.%According to the production process characteristics and the structure characteristics of the camshaft,an automated production line of iron-type coated sand casting process for camshaft castings was successfully designed to improve the efficiency of production camshaft with high productivity and low emissions,which lay the foundation for the popularization and application of iron-type coated sand casting process.
Relativistic RPA in axial symmetry
Arteaga, D Pena; 10.1103/PhysRevC.77.034317
2009-01-01
Covariant density functional theory, in the framework of self-consistent Relativistic Mean Field (RMF) and Relativistic Random Phase approximation (RPA), is for the first time applied to axially deformed nuclei. The fully self-consistent RMF+RRPA equations are posed for the case of axial symmetry and non-linear energy functionals, and solved with the help of a new parallel code. Formal properties of RPA theory are studied and special care is taken in order to validate the proper decoupling of spurious modes and their influence on the physical response. Sample applications to the magnetic and electric dipole transitions in $^{20}$Ne are presented and analyzed.
Multifragmentation calculated with relativistic forces
Feldmeier, H; Papp, G
1995-01-01
A saturating hamiltonian is presented in a relativistically covariant formalism. The interaction is described by scalar and vector mesons, with coupling strengths adjusted to the nuclear matter. No explicit density depe ndence is assumed. The hamiltonian is applied in a QMD calculation to determine the fragment distribution in O + Br collision at different energies (50 -- 200 MeV/u) to test the applicability of the model at low energies. The results are compared with experiment and with previous non-relativistic calculations. PACS: 25.70Mn, 25.75.+r
Relativistic Stern-Gerlach Deflection
Talman, Richard
2016-01-01
Modern advances in polarized beam control should make it possible to accurately measure Stern-Gerlach (S-G) deflection of relativistic beams. Toward this end a relativistically covariant S-G formalism is developed that respects the opposite behavior under inversion of electric and magnetic fields. Not at all radical, or even new, this introduces a distinction between electric and magnetic fields that is not otherwise present in pure Maxwell theory. Experimental configurations (mainly using polarized electron beams passing through magnetic or electric quadrupoles) are described. Electron beam preparation and experimental methods needed to detect the extremely small deflections are discussed.
Special Relativistic Hydrodynamics with Gravitation
Hwang, Jai-chan; Noh, Hyerim
2016-12-01
Special relativistic hydrodynamics with weak gravity has hitherto been unknown in the literature. Whether such an asymmetric combination is possible has been unclear. Here, the hydrodynamic equations with Poisson-type gravity, considering fully relativistic velocity and pressure under the weak gravity and the action-at-a-distance limit, are consistently derived from Einstein’s theory of general relativity. An analysis is made in the maximal slicing, where the Poisson’s equation becomes much simpler than our previous study in the zero-shear gauge. Also presented is the hydrodynamic equations in the first post-Newtonian approximation, now under the general hypersurface condition. Our formulation includes the anisotropic stress.
Special relativistic hydrodynamics with gravitation
Hwang, Jai-chan
2016-01-01
The special relativistic hydrodynamics with weak gravity is hitherto unknown in the literature. Whether such an asymmetric combination is possible was unclear. Here, the hydrodynamic equations with Poisson-type gravity considering fully relativistic velocity and pressure under the weak gravity and the action-at-a-distance limit are consistently derived from Einstein's general relativity. Analysis is made in the maximal slicing where the Poisson's equation becomes much simpler than our previous study in the zero-shear gauge. Also presented is the hydrodynamic equations in the first post-Newtonian approximation, now under the {\\it general} hypersurface condition. Our formulation includes the anisotropic stress.
Vector Theory in Relativistic Thermodynamics
刘泽文
1994-01-01
It is pointed out that five defects occur in Planck-Einstein’s relativistic thermodynamics (P-E theory). A vector theory in relativistic thermodynamics (VTRT) is established. Defining the internal energy as a 4-vector, and supposing the entropy and the number of. particles to be invariants we have derived the transformations of all quantities, and subsequently got the Lagrangian and 4-D forms of thermodynamic laws. In order to test the new theory, several exact solutions with classical limits are given. The VTRT is free from the defects of the P-E theory.
Frontiers in relativistic celestial mechanics
2014-01-01
Relativistic celestial mechanics – investigating the motion celestial bodies under the influence of general relativity – is a major tool of modern experimental gravitational physics. With a wide range of prominent authors from the field, this two-volume series consists of reviews on a multitude of advanced topics in the area of relativistic celestial mechanics – starting from more classical topics such as the regime of asymptotically-flat spacetime, light propagation and celestial ephemerides, but also including its role in cosmology and alternative theories of gravity as well as modern experiments in this area.
Messa, Emanuela; Carturan, Sonia; Maffè, Chiara; Pautasso, Marisa; Bracco, Enrico; Roetto, Antonella; Messa, Francesca; Arruga, Francesca; Defilippi, Ilaria; Rosso, Valentina; Zanone, Chiara; Rotolo, Antonia; Greco, Elisabetta; Pellegrino, Rosa M.; Alberti, Daniele; Saglio, Giuseppe; Cilloni, Daniela
2010-01-01
Background Usefulness of iron chelation therapy in myelodysplastic patients is still under debate but many authors suggest its possible role in improving survival of low-risk myelodysplastic patients. Several reports have described an unexpected effect of iron chelators, such as an improvement in hemoglobin levels, in patients affected by myelodysplastic syndromes. Furthermore, the novel chelator deferasirox induces a similar improvement more rapidly. Nuclear factor-κB is a key regulator of many cellular processes and its impaired activity has been described in different myeloid malignancies including myelodysplastic syndromes. Design and Methods We evaluated deferasirox activity on nuclear factor-κB in myelodysplastic syndromes as a possible mechanism involved in hemoglobin improvement during in vivo treatment. Forty peripheral blood samples collected from myelodysplastic syndrome patients were incubated with 50 μM deferasirox for 18h. Results Nuclear factor-κB activity dramatically decreased in samples showing high basal activity as well as in cell lines, whereas no similar behavior was observed with other iron chelators despite a similar reduction in reactive oxygen species levels. Additionally, ferric hydroxyquinoline incubation did not decrease deferasirox activity in K562 cells suggesting the mechanism of action of the drug is independent from cell iron deprivation by chelation. Finally, incubation with both etoposide and deferasirox induced an increase in K562 apoptotic rate. Conclusions Nuclear factor-κB inhibition by deferasirox is not seen from other chelators and is iron and reactive oxygen species scavenging independent. This could explain the hemoglobin improvement after in vivo treatment, such that our hypothesis needs to be validated in further prospective studies. PMID:20534700
Relativistic Hydrodynamics for Heavy-Ion Collisions
Ollitrault, Jean-Yves
2008-01-01
Relativistic hydrodynamics is essential to our current understanding of nucleus-nucleus collisions at ultrarelativistic energies (current experiments at the Relativistic Heavy Ion Collider, forthcoming experiments at the CERN Large Hadron Collider). This is an introduction to relativistic hydrodynamics for graduate students. It includes a detailed…
Efficient Acceleration of Relativistic Magnetohydrodynamic Jets
Toma, Kenji
2013-01-01
Relativistic jets in active galactic nuclei, galactic microquasars, and gamma-ray bursts are widely considered to be magnetohydrodynamically driven by black hole accretion systems, although conversion mechanism from Poynting into particle kinetic energy flux is still open. Recent detailed numerical and analytical studies of global structures of steady, axisymmetric magnetohydrodynamic (MHD) flows with specific boundary conditions have not reproduced as rapid an energy conversion as required by observations. In order to find more suitable boundary conditions, we focus on the flow along a poloidal magnetic field line just inside the external boundary, without treating transfield force balance in detail. We find some examples of the poloidal field structure and corresponding external pressure profile for an efficient and rapid energy conversion as required by observations, and that the rapid acceleration requires a rapid decrease of the external pressure above the accretion disk. We also clarify the differences ...
Optical principles of beam transport for relativistic electron cooling
A. Burov
2000-09-01
Full Text Available In conventional low energy electron coolers, the electron beam is immersed in a continuous solenoid, which provides a calm and tightly focused beam in a cooling section. While suitable for low energies, the continuity of the accompanying magnetic field is hardly realizable at relativistic energies. We consider the possibility of using an extended solenoid in the gun and the cooling section only, applying lumped focusing for the rest of the electron transport line.
L-shell Auger and Coster-Kronig spectra from relativistic theory
Chen, M. H.; Crasemann, B.; Aoyagi, M.; Mark, H.
1979-01-01
The intensities of L-shell Auger and Coster-Kronig transitions in heavy atoms have been calculated relativistically. A detailed comparison is made with measured Auger spectra of Pt and U. The pertinent transition energies were computed from relativistic wave functions with inclusion of the Breit interaction, self-energy, a vacuum-polarization correction, and complete atomic relaxation. Multiplet splitting is found to distribute Auger electrons from certain transitions among several lines. The analysis leads to reassignment of a number of lines in the measured spectra. Lines originally identified as L2-L3Ni in the U spectrum are shown to arise from M4,5 Auger transitions instead.
Microscopic Processes in Relativistic Jets
Nishikawa, K.-I.; Hardee, P.; Mizuno, Y.; Medvedev, M.; Zhang, B.; Nordlund, A.; Fredricksen, J.; Sol, H.; Niemiec, J.; Lyubarsky, Y.;
2008-01-01
Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., gamma-ray bursts (GRBs), active galactic nuclei (AGNs), and Galactic microquasar systems usually have power-law emission spectra. Recent PIC simulations of relativistic electron-ion (electro-positron) jets injected into a stationary medium show that particle acceleration occurs within the downstream jet. In the collisionless relativistic shock particle acceleration is due to plasma waves and their associated instabilities (e.g., the Buneman instability, other two-streaming instability, and the Weibel (filamentation) instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The 'jitter' radiation from deflected electrons has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.
The Highest Redshift Relativistic Jets
Cheung, C.C.; Stawarz, L.; Siemiginowska, A.; Harris, D.E; Schwartz, D.A.; Wardle, J.F.C.; Gobeille, D.; Lee, N.P.
2007-12-18
We describe our efforts to understand large-scale (10's-100's kpc) relativistic jet systems through observations of the highest-redshift quasars. Results from a VLA survey search for radio jets in {approx} 30 z > 3.4 quasars are described along with new Chandra observations of 4 selected targets.
Circular polarization in relativistic jets
Macquart, JP
2003-01-01
Circular polarization is observed in some relativistic jet sources at radio wavelengths. It is largely associated with activity in the cores of the radio sources, is highly variable, and is strongest during ejection episodes. VLBI imaging and interstellar scintillation arguments show that the degree
Particle Acceleration in Relativistic Magnetized Collisionless Electron-Ion Shocks
Sironi, Lorenzo
2010-01-01
We investigate shock structure and particle acceleration in relativistic magnetized collisionless electron-ion shocks by means of 2.5D particle-in-cell simulations with ion-to-electron mass ratios (m_i/m_e) ranging from 16 to 1000. We explore a range of inclination angles between the pre-shock magnetic field and the shock normal. In "subluminal" shocks, where relativistic particles can escape ahead of the shock along the magnetic field lines, ions are efficiently accelerated via a Fermi-like mechanism. The downstream ion spectrum consists of a relativistic Maxwellian and a high-energy power-law tail, which contains ~5% of ions and ~30% of ion energy. Its slope is -2.1. Upstream electrons enter the shock with lower energy than ions, so they are more strongly tied to the field. As a result, only ~1% of the incoming electrons are Fermi-accelerated at the shock before being advected downstream, where they populate a steep power-law tail (with slope -3.5). For "superluminal" shocks, where relativistic particles ca...
Fast lattice Boltzmann solver for relativistic hydrodynamics.
Mendoza, M; Boghosian, B M; Herrmann, H J; Succi, S
2010-07-01
A lattice Boltzmann formulation for relativistic fluids is presented and numerically validated through quantitative comparison with recent hydrodynamic simulations of relativistic fluids. In order to illustrate its capability to handle complex geometries, the scheme is also applied to the case of a three-dimensional relativistic shock wave, generated by a supernova explosion, impacting on a massive interstellar cloud. This formulation opens up the possibility of exporting the proven advantages of lattice Boltzmann methods, namely, computational efficiency and easy handling of complex geometries, to the context of (mildly) relativistic fluid dynamics at large, from quark-gluon plasmas up to supernovae with relativistic outflows.
Miller, J.M.; Raymond, J.; Fabian, A.C.; Homan, J.; Nowak, M.A.; Wijnands, R.A.D.; van der Klis, M.; Belloni, T.; Tomsick, J.A.; Smith, D.M.; Charles, P.A.; Lewin, W.H.G.
2004-01-01
We observed the Galactic black hole GX 339-4 with the Chandra High Energy Transmission Grating Spectrometer (HETGS) for 75 ks during the decline of its 2002-2003 outburst. The sensitivity of this observation provides an unprecedented glimpse of a Galactic black hole at about a tenth of the luminosit
Relativistic Cosmology Revisited
Crothers S. J.
2007-04-01
Full Text Available In a previous paper the writer treated of particular classes of cosmological solutions for certain Einstein spaces and claimed that no such solutions exist in relation thereto. In that paper the assumption that the proper radius is zero when the line-element is singular was generally applied. This general assumption is unjustified and must be dropped. Consequently, solutions do exist in relation to the aforementioned types, and are explored herein. The concept of the Big Bang cosmology is found to be inconsistent with General Relativity
Scrimshaw, N S
1991-10-01
The world's leading nutritional problem is iron deficiency. 66% of children and women aged 15-44 years in developing countries have it. Further, 10-20% of women of childbearing age in developed countries are anemic. Iron deficiency is identified with often irreversible impairment of a child's learning ability. It is also associated with low capacity for adults to work which reduces productivity. In addition, it impairs the immune system which reduces the body's ability to fight infection. Iron deficiency also lowers the metabolic rate and the body temperature when exposed to cold. Hemoglobin contains nearly 73% of the body's iron. This iron is always being recycled as more red blood cells are made. The rest of the needed iron does important tasks for the body, such as binds to molecules that are reservoirs of oxygen for muscle cells. This iron comes from our diet, especially meat. Even though some plants, such as spinach, are high in iron, the body can only absorb 1.4-7% of the iron in plants whereas it can absorb 20% of the iron in red meat. In many developing countries, the common vegetarian diets contribute to high rates of iron deficiency. Parasitic diseases and abnormal uterine bleeding also promote iron deficiency. Iron therapy in anemic children can often, but not always, improve behavior and cognitive performance. Iron deficiency during pregnancy often contributes to maternal and perinatal mortality. Yet treatment, if given to a child in time, can lead to normal growth and hinder infections. However, excess iron can be damaging. Too much supplemental iron in a malnourished child promotes fatal infections since the excess iron is available for the pathogens use. Many countries do not have an effective system for diagnosing, treating, and preventing iron deficiency. Therefore a concerted international effort is needed to eliminate iron deficiency in the world.
General relativistic modelling of the negative reverberation X-ray time delays in AGN
Emmanoulopoulos, D; Dovciak, M; McHardy, I M
2014-01-01
We present the first systematic physical modelling of the time-lag spectra between the soft (0.3-1 keV) and the hard (1.5-4 keV) X-ray energy bands, as a function of Fourier frequency, in a sample of 12 active galactic nuclei which have been observed by XMM-Newton. We concentrate particularly on the negative X-ray time-lags (typically seen above $10^{-4}$ Hz) i.e. soft band variations lag the hard band variations, and we assume that they are produced by reprocessing and reflection by the accretion disc within a lamp-post X-ray source geometry. We also assume that the response of the accretion disc, in the soft X-ray bands, is adequately described by the response in the neutral iron line (Fe k$\\alpha$) at 6.4 keV for which we use fully general relativistic ray-tracing simulations to determine its time evolution. These response functions, and thus the corresponding time-lag spectra, yield much more realistic results than the commonly-used, but erroneous, top-hat models. Additionally we parametrize the positive ...
Maximum stellar iron core mass
F W Giacobbe
2003-03-01
An analytical method of estimating the mass of a stellar iron core, just prior to core collapse, is described in this paper. The method employed depends, in part, upon an estimate of the true relativistic mass increase experienced by electrons within a highly compressed iron core, just prior to core collapse, and is signiﬁcantly different from a more typical Chandrasekhar mass limit approach. This technique produced a maximum stellar iron core mass value of 2.69 × 1030 kg (1.35 solar masses). This mass value is very near to the typical mass values found for neutron stars in a recent survey of actual neutron star masses. Although slightly lower and higher neutron star masses may also be found, lower mass neutron stars are believed to be formed as a result of enhanced iron core compression due to the weight of non-ferrous matter overlying the iron cores within large stars. And, higher mass neutron stars are likely to be formed as a result of fallback or accretion of additional matter after an initial collapse event involving an iron core having a mass no greater than 2.69 × 1030 kg.
Covariant electromagnetic field lines
Hadad, Y.; Cohen, E.; Kaminer, I.; Elitzur, A. C.
2017-08-01
Faraday introduced electric field lines as a powerful tool for understanding the electric force, and these field lines are still used today in classrooms and textbooks teaching the basics of electromagnetism within the electrostatic limit. However, despite attempts at generalizing this concept beyond the electrostatic limit, such a fully relativistic field line theory still appears to be missing. In this work, we propose such a theory and define covariant electromagnetic field lines that naturally extend electric field lines to relativistic systems and general electromagnetic fields. We derive a closed-form formula for the field lines curvature in the vicinity of a charge, and show that it is related to the world line of the charge. This demonstrates how the kinematics of a charge can be derived from the geometry of the electromagnetic field lines. Such a theory may also provide new tools in modeling and analyzing electromagnetic phenomena, and may entail new insights regarding long-standing problems such as radiation-reaction and self-force. In particular, the electromagnetic field lines curvature has the attractive property of being non-singular everywhere, thus eliminating all self-field singularities without using renormalization techniques.
A String Motivated Approach to the Relativistic Point Particle
Tuite, M P; Tuite, Michael; Sen, Siddhartha
2003-01-01
Using concepts developed in string theory, Cohen, Moore, Nelson and Polchinski calculated the propagator for a relativistic point particle. Following these authors we extend the technique to include the case of closed world lines. The partition function found corresponds to the Feynmann and Schwinger proper time formalism. We also explicitly verify that the partition function is equivalent to the usual path length action partition function. As an example of a sum over closed world lines, we compute the Euler-Heisenberg effective Lagrangian in a novel way.
Khoshgard, Karim; Kiani, Parvaneh; Haghparast, Abbas; Hosseinzadeh, Leila; Eivazi, Mohammad Taghi
2017-08-01
The aim of radiotherapy is to deliver lethal damage to cancerous tissue while preserving adjacent normal tissues. Radiation absorbed dose of the tumoral cells can increase when high atomic nanoparticles are present in them during irradiation. Also, the dose rate is an important aspect in radiation effects that determines the biological results of a given dose. This in vitro study investigated the dose-rate effect on the induced radiosensitivity by dextran-coated iron oxide in cancer cells. HeLa and MCF-7 cells were cultured in vitro and incubated with different concentrations of dextran-coated iron oxide nanoparticles. They were then irradiated with 6 MV photons at dose rates of 43, 185 and 370 cGy/min. The MTT test was used to obtain the cells' survival after 48 h of irradiations. Incubating the cells with the nanoparticles at concentrations of 10, 40 and 80 μg/ml showed no significant cytotoxicity effect. Dextran-coated iron oxide nanoparticles showed more radiosensitivity effect by increasing the dose rate and nanoparticles concentration. Radiosensitization enhancement factors of MCF-7 and HeLa cells at a dose-rate of 370 cGy/min and nanoparticles' concentration of 80 μg/ml were 1.21 ± 0.06 and 1.19 ± 0.04, respectively. Increasing the dose rate of 6 MV photons irradiation in MCF-7 and HeLa cells increases the radiosensitization induced by the dextran-coated iron nanoparticles in these cells.
Relativistic electron beams above thunderclouds
Füellekrug, M.; Roussel-Dupre, R.; Symbalisty, E. M. D.;
2011-01-01
Non-luminous relativistic electron beams above thunderclouds have been detected by the radio signals of low frequency similar to 40-400 kHz which they radiate. The electron beams occur similar to 2-9 ms after positive cloud-to-ground lightning discharges at heights between similar to 22-72 km above...... thunderclouds. Intense positive lightning discharges can also cause sprites which occur either above or prior to the electron beam. One electron beam was detected without any luminous sprite which suggests that electron beams may also occur independently of sprites. Numerical simulations show that beams...... of electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of similar to 7MeV to transport a total charge of similar to-10mC upwards. The impulsive current similar to 3 x 10(-3) Am-2 associated with relativistic electron beams above thunderclouds...
Relativistic electron beams above thunderclouds
M. Füllekrug
2011-05-01
Full Text Available Non-luminous relativistic electron beams above thunderclouds are detected by radio remote sensing with low frequency radio signals from 40–400 kHz. The electron beams occur 2–9 ms after positive cloud-to-ground lightning discharges at heights between 22–72 km above thunderclouds. The positive lightning discharges also cause sprites which occur either above or before the electron beam. One electron beam was detected without any luminous sprite occurrence which suggests that electron beams may also occur independently. Numerical simulations show that the beamed electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of 7 MeV to transport a total charge of 10 mC upwards. The impulsive current associated with relativistic electron beams above thunderclouds is directed downwards and needs to be considered as a novel element of the global atmospheric electric circuit.
Volatility smile as relativistic effect
Kakushadze, Zura
2017-06-01
We give an explicit formula for the probability distribution based on a relativistic extension of Brownian motion. The distribution (1) is properly normalized and (2) obeys the tower law (semigroup property), so we can construct martingales and self-financing hedging strategies and price claims (options). This model is a 1-constant-parameter extension of the Black-Scholes-Merton model. The new parameter is the analog of the speed of light in Special Relativity. However, in the financial context there is no ;speed limit; and the new parameter has the meaning of a characteristic diffusion speed at which relativistic effects become important and lead to a much softer asymptotic behavior, i.e., fat tails, giving rise to volatility smiles. We argue that a nonlocal stochastic description of such (Lévy) processes is inadequate and discuss a local description from physics. The presentation is intended to be pedagogical.
Double Relativistic Electron Accelerating Mirror
Saltanat Sadykova
2013-02-01
Full Text Available In the present paper, the possibility of generation of thin dense relativistic electron layers is shown using the analytical and numerical modeling of laser pulse interaction with ultra-thin layers. It was shown that the maximum electron energy can be gained by optimal tuning between the target width, intensity and laser pulse duration. The optimal parameters were obtained from a self-consistent system of Maxwell equations and the equation of motion of electron layer. For thin relativistic electron layers, the gaining of maximum electron energies requires a second additional overdense plasma layer, thus cutting the laser radiation off the plasma screen at the instant of gaining the maximum energy (DREAM-schema.
Relativistic stars in bigravity theory
Aoki, Katsuki; Tanabe, Makoto
2016-01-01
Assuming static and spherically symmetric spacetimes in the ghost-free bigravity theory, we find a relativistic star solution, which is very close to that in general relativity. The coupling constants are classified into two classes: Class [I] and Class [II]. Although the Vainshtein screening mechanism is found in the weak gravitational field for both classes, we find that there is no regular solution beyond the critical value of the compactness in Class [I]. This implies that the maximum mass of a neutron star in Class [I] becomes much smaller than that in GR. On the other hand, for the solution in Class [II], the Vainshtein screening mechanism works well even in a relativistic star and the result in GR is recovered.
Relativistic Hydrodynamics on Graphic Cards
Gerhard, Jochen; Bleicher, Marcus
2012-01-01
We show how to accelerate relativistic hydrodynamics simulations using graphic cards (graphic processing units, GPUs). These improvements are of highest relevance e.g. to the field of high-energetic nucleus-nucleus collisions at RHIC and LHC where (ideal and dissipative) relativistic hydrodynamics is used to calculate the evolution of hot and dense QCD matter. The results reported here are based on the Sharp And Smooth Transport Algorithm (SHASTA), which is employed in many hydrodynamical models and hybrid simulation packages, e.g. the Ultrarelativistic Quantum Molecular Dynamics model (UrQMD). We have redesigned the SHASTA using the OpenCL computing framework to work on accelerators like graphic processing units (GPUs) as well as on multi-core processors. With the redesign of the algorithm the hydrodynamic calculations have been accelerated by a factor 160 allowing for event-by-event calculations and better statistics in hybrid calculations.
A relativistic symmetry in nuclei
Ginocchio, J N [MS B283, Theoretical Division, Los Alamos National Laboratory Los Alamos, New Mexico 87545 (Mexico)
2007-11-15
We review some of the empirical and theoretical evidence supporting pseudospin symmetry in nuclei as a relativistic symmetry. We review the case that the eigenfunctions of realistic relativistic nuclear mean fields approximately conserve pseudospin symmetry in nuclei. We discuss the implications of pseudospin symmetry for magnetic dipole transitions and Gamow-Teller transitions between states in pseudospin doublets. We explore a more fundamental rationale for pseudospin symmetry in terms of quantum chromodynamics (QCD), the basic theory of the strong interactions. We show that pseudospin symmetry in nuclei implies spin symmetry for an anti-nucleon in a nuclear environment. We also discuss the future and what role pseudospin symmetry may be expected to play in an effective field theory of nucleons.
Fluctuations in Relativistic Causal Hydrodynamics
Kumar, Avdhesh; Mishra, Ananta P
2013-01-01
The formalism to calculate the hydrodynamics fluctuation using the quasi-stationary fluctuation theory of Onsager to the relativistic Navier-Stokes hydrodynamics is already known. In this work we calculate hydrodynamic fluctuations in relativistic causal theory of Muller, Israel and Stewart and other related causal hydrodynamic theories. We show that expressions for the Onsager coefficients and the correlation functions have form similar to the ones obtained by using Navier-Stokes equation. However, temporal evolution of the correlation functions obtained using MIS and the other causal theories can be significantly different than the correlation functions obtained using the Navier-Stokes equation. Finally, as an illustrative example, we explicitly plot the correlation functions obtained using the causal-hydrodynamics theories and compare them with correlation functions obtained by earlier authors using the expanding boost-invariant (Bjorken) flows.
Brooks, Charles Kent
2015-01-01
, a situation unique in the Solar System. In such a world, iron metal is unstable and, as we all know, oxidizes to the ferric iron compounds we call 'rust'. If we require iron metal it must be produced at high temperatures by reacting iron ore, usually a mixture of ferrous (Fe2+) and ferric (Fe3+) oxides (Fe2O3......, hematite, or FeO.Fe2O3, magnetite), with carbon in the form of coke. This is carried out in a blast furnace. Although the Earth's core consists of metallic iron, which may also be present in parts of the mantle, this is inaccessible to us, so we must make our own. In West Greenland, however, some almost...... unique examples of iron metal, otherwise called 'native iron' or 'telluric iron', occur naturally....
Thermodynamic and relativistic uncertainty relations
Artamonov, A. A.; Plotnikov, E. M.
2017-01-01
Thermodynamic uncertainty relation (UR) was verified experimentally. The experiments have shown the validity of the quantum analogue of the zeroth law of stochastic thermodynamics in the form of the saturated Schrödinger UR. We have also proposed a new type of UR for the relativistic mechanics. These relations allow us to consider macroscopic phenomena within the limits of the ratio of the uncertainty relations for different physical quantities.
Pythagoras Theorem and Relativistic Kinematics
Mulaj, Zenun; Dhoqina, Polikron
2010-01-01
In two inertial frames that move in a particular direction, may be registered a light signal that propagates in an angle with this direction. Applying Pythagoras theorem and principles of STR in both systems, we can derive all relativistic kinematics relations like the relativity of simultaneity of events, of the time interval, of the length of objects, of the velocity of the material point, Lorentz transformations, Doppler effect and stellar aberration.
Relativistic Binaries in Globular Clusters
Benacquista Matthew J.
2006-02-01
Full Text Available The galactic population of globular clusters are old, dense star systems, with a typical cluster containing 10^4 - 10^7 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss the theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution which lead to relativistic binaries, and current and possible future observational evidence for this population. Globular cluster evolution will focus on the properties that boost the production of hard binary systems and on the tidal interactions of the galaxy with the cluster, which tend to alter the structure of the globular cluster with time. The interaction of the components of hard binary systems alters the evolution of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker-Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.
Relativistic Binaries in Globular Clusters
Benacquista Matthew
2002-01-01
Full Text Available The galactic population of globular clusters are old, dense star systems, with a typical cluster containing $10^4 - 10^6$ stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss the theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution which lead to relativistic binaries, and current and possible future observational evidence for this population. Globular cluster evolution will focus on the properties that boost the production of hard binary systems and on the tidal interactions of the galaxy with the cluster, which tend to alter the structure of the globular cluster with time. The interaction of the components of hard binary systems alters the evolution of both bodies and can lead to exotic objects. Direct $N$-body integrations and Fokker--Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.
Relativistic Binaries in Globular Clusters
Matthew J. Benacquista
2013-03-01
Full Text Available Galactic globular clusters are old, dense star systems typically containing 10^4 – 10^6 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution that leads to relativistic binaries, and current and possible future observational evidence for this population. Our discussion of globular cluster evolution will focus on the processes that boost the production of tight binary systems and the subsequent interaction of these binaries that can alter the properties of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker–Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.
Relativistic Tennis Using Flying Mirror
Pirozhkov, A. S.; Kando, M.; Esirkepov, T. Zh.; Ma, J.; Fukuda, Y.; Chen, L.-M.; Daito, I.; Ogura, K.; Homma, T.; Hayashi, Y.; Kotaki, H.; Sagisaka, A.; Mori, M.; Koga, J. K.; Kawachi, T.; Daido, H.; Bulanov, S. V.; Kimura, T.; Kato, Y.; Tajima, T.
2008-06-01
Upon reflection from a relativistic mirror, the electromagnetic pulse frequency is upshifted and the duration is shortened by the factor proportional to the relativistic gamma-factor squared due to the double Doppler effect. We present the results of the proof-of-principle experiment for frequency upshifting of the laser pulse reflected from the relativistic "flying mirror", which is a wake wave near the breaking threshold created by a strong driver pulse propagating in underdense plasma. Experimentally, the wake wave is created by a 2 TW, 76 fs Ti:S laser pulse from the JLITE-X laser system in helium plasma with the electron density of ≈4-6×1019 cm-3. The reflected signal is observed with a grazing-incidence spectrograph in 24 shots. The wavelength of the reflected radiation ranges from 7 to 14 nm, the corresponding frequency upshifting factors are ˜55-115, and the gamma-factors are y = 4-6. The reflected signal contains at least 3×107 photons/sr. This effect can be used to generate coherent high-frequency ultrashort pulses that inherit temporal shape and polarization from the original (low-frequency) ones. Apart from this, the reflected radiation contains important information about the wake wave itself, e.g. location, size, phase velocity, etc.
Magnetohydrodynamics of Chiral Relativistic Fluids
Boyarsky, Alexey; Ruchayskiy, Oleg
2015-01-01
We study the dynamics of a plasma of charged relativistic fermions at very high temperature $T\\gg m$, where $m$ is the fermion mass, coupled to the electromagnetic field. In particular, we derive a magneto-hydrodynamical description of the evolution of such a plasma. We show that, as compared to conventional MHD for a plasma of non-relativistic particles, the hydrodynamical description of the relativistic plasma involves new degrees of freedom described by a pseudo-scalar field originating in a local asymmetry in the densities of left-handed and right-handed fermions. This field can be interpreted as an effective axion field. Taking into account the chiral anomaly we present dynamical equations for the evolution of this field, as well as of other fields appearing in the MHD description of the plasma. Due to its non-linear coupling to helical magnetic fields, the axion field significantly affects the dynamics of a magnetized plasma and can give rise to a novel type of inverse cascade.
Kim, Yongbae; Olivi, Luisa; Cheong, Jae Hoon; Maertens, Alex; Joseph P Bressler
2007-01-01
Aluminum and other trivalent metals were shown to stimulate uptake of transferrin bound iron and nontransferrin bound iron in erytholeukemia and hepatoma cells. Because of the association between aluminum and Alzheimer’s Disease, and findings of higher levels of iron in Alzheimer’s disease brains, the effects of aluminum on iron homeostasis were examined in a human glial cell line. Aluminum stimulated dose- and time-dependent uptake of nontransferrin bound iron and iron bound to transferrin. ...
The ‘twin paradox’ in relativistic rigid motion
Ben-Ya'acov, Uri
2016-09-01
Relativistic rigid motion suggests a new version for the so-called ‘twin paradox’, comparing the ages of two astronauts on a very long spaceship. Although there is always an instantaneous inertial frame in which the whole spaceship, being rigid, is simultaneously at rest, the twins’ ages, measured as the proper-times along their individual world lines, are different when they are located at remote parts of the spaceship. The age, or proper-time, difference depends on the distance at rest between the astronauts and the rapidity difference between start to end. The relation of the age difference with the relative Doppler shift of light signals transmitted between the astronauts and implications for the possibility to assign a common age (proper-time) to complex, spatially extended, relativistic systems are also discussed.
On Magnetic Self-Collimation of Relativistic Jets
Globus, N.; Cayatte, V.; Sauty, C.
We present a semi-analytical model using the equations of general relativistic magnetohydrodynamics (GRMHD) for jets emitted by a rotating black hole. We assume steady axisymmetric outflows of a relativistic ideal fluid in Kerr metrics. We express the conservation equations in the frame of the FIDucial Observer (FIDO or ZAMO) using a 3+1 space-time splitting. Calculating the total energy variation between a non-polar field line and the polar axis, we extend to the Kerr metric the simple criterion for the magnetic collimation of jets obtained for a nonrotating black hole by Meliani et al.10 We show that the black role rotation induced a more efficient magnetic collimation of the jet.
Iron Homeostasis and Nutritional Iron Deficiency123
2011-01-01
Nonheme food ferritin (FTN) iron minerals, nonheme iron complexes, and heme iron contribute to the balance between food iron absorption and body iron homeostasis. Iron absorption depends on membrane transporter proteins DMT1, PCP/HCP1, ferroportin (FPN), TRF2, and matriptase 2. Mutations in DMT1 and matriptase-2 cause iron deficiency; mutations in FPN, HFE, and TRF2 cause iron excess. Intracellular iron homeostasis depends on coordinated regulation of iron trafficking and storage proteins enc...
Relativistic effects in Lyman-alpha forest
Iršič, Vid; Viel, Matteo
2015-01-01
We present the calculation of the Lyman-alpha (Lyman-$\\alpha$) transmitted flux fluctuations with full relativistic corrections to the first order. Even though several studies exist on relativistic effects in galaxy clustering, this is the first study to extend the formalism to a different tracer of underlying matter at unique redshift range ($z = 2 - 5$). Furthermore, we show a comprehensive application of our calculations to the Quasar- Lyman-$\\alpha$ cross-correlation function. Our results indicate that the signal of relativistic effects can be as large as 30% at Baryonic Acoustic Oscillation (BAO) scale, which is much larger than anticipated and mainly due to the large differences in density bias factors of our tracers. We construct an observable, the anti-symmetric part of the cross- correlation function, that is dominated by the relativistic signal and offers a new way to measure the relativistic terms at relatively small scales. The analysis shows that relativistic effects are important when considerin...
Transverse relativistic effects in paraxial wave interference
Bliokh, Konstantin Y; Nori, Franco
2013-01-01
We consider relativistic deformations of interfering paraxial waves moving in the transverse direction. Owing to superluminal transverse phase velocities, noticeable deformations of the interference patterns arise when the waves move with respect to each other with non-relativistic velocities. Similar distortions also appear on a mutual tilt of the interfering waves, which causes a phase delay analogous to the relativistic time delay. We illustrate these observations by the interference between a vortex wave beam and a plane wave, which exhibits a pronounced deformation of the radial fringes into a fork-like pattern (relativistic Hall effect). Furthermore, we describe an additional relativistic motion of the interference fringes (a counter-rotation in the vortex case), which become noticeable at the same non-relativistic velocities.
Entropy current for non-relativistic fluid
Banerjee, Nabamita; Jain, Akash; Roychowdhury, Dibakar
2014-01-01
We study transport properties of a parity-odd, non-relativistic charged fluid in presence of background electric and magnetic fields. To obtain stress tensor and charged current for the non-relativistic system we start with the most generic relativistic fluid, living in one higher dimension and reduce the constituent equations along the light-cone direction. We also reduce the equation satisfied by the entropy current of the relativistic theory and obtain a consistent entropy current for the non-relativistic system (we call it "canonical form" of the entropy current). Demanding that the non-relativistic fluid satisfies the second law of thermodynamics we impose constraints on various first order transport coefficients. For parity even fluid, this is straight forward; it tells us positive definiteness of different transport coefficients like viscosity, thermal conductivity, electric conductivity etc. However for parity-odd fluid, canonical form of the entropy current fails to confirm the second law of thermody...
Non-Relativistic Spacetimes with Cosmological Constant
Aldrovandi, R.; Barbosa, A. L.; Crispino, L.C.B.; Pereira, J. G.
1998-01-01
Recent data on supernovae favor high values of the cosmological constant. Spacetimes with a cosmological constant have non-relativistic kinematics quite different from Galilean kinematics. De Sitter spacetimes, vacuum solutions of Einstein's equations with a cosmological constant, reduce in the non-relativistic limit to Newton-Hooke spacetimes, which are non-metric homogeneous spacetimes with non-vanishing curvature. The whole non-relativistic kinematics would then be modified, with possible ...
Relativistic non-equilibrium thermodynamics revisited
García-Colin, L S
2006-01-01
Relativistic irreversible thermodynamics is reformulated following the conventional approach proposed by Meixner in the non-relativistic case. Clear separation between mechanical and non-mechanical energy fluxes is made. The resulting equations for the entropy production and the local internal energy have the same structure as the non-relativistic ones. Assuming linear constitutive laws, it is shown that consistency is obtained both with the laws of thermodynamics and causality.
Analogy betwen dislocation creep and relativistic cosmology
J.A. Montemayor-Aldrete; J.D. Muñoz-Andrade; Mendoza-Allende, A.; Montemayor-Varela, A.
2005-01-01
A formal, physical analogy between plastic deformation, mainly dislocation creep, and Relativistic Cosmology is presented. The physical analogy between eight expressions for dislocation creep and Relativistic Cosmology have been obtained. By comparing the mathematical expressions and by using a physical analysis, two new equations have been obtained for dislocation creep. Also, four new expressions have been obtained for Relativistic Cosmology. From these four new equations, one may determine...
A relativistic correction to semiclassical charmonium
Weiss, J.
1995-09-01
It is shown that the relativistic linear potentials, introduced by the author within the particle à la Wheeler-Feynman direct-interaction (AAD) theory, applied to the semiclassically quantized charmonium, yield energy spectrum comparable to that of some known models. Using the expansion of the relativistic linear AAD potentials in powers ofc -1, the charmonium spectrum, given as a rule by Bohr-Sommerfeld quantization of circular orbits, is extended up to the second order of relativistic corrections.
Generalized One-Dimensional Point Interaction in Relativistic and Non-relativistic Quantum Mechanics
Shigehara, T; Mishima, T; Cheon, T; Cheon, Taksu
1999-01-01
We first give the solution for the local approximation of a four parameter family of generalized one-dimensional point interactions within the framework of non-relativistic model with three neighboring $\\delta$ functions. We also discuss the problem within relativistic (Dirac) framework and give the solution for a three parameter family. It gives a physical interpretation for so-called high energy substantially differ between non-relativistic and relativistic cases.
Relativistic Cyclotron Instability in Anisotropic Plasmas
López, Rodrigo A.; Moya, Pablo S.; Navarro, Roberto E.; Araneda, Jaime A.; Muñoz, Víctor; Viñas, Adolfo F.; Alejandro Valdivia, J.
2016-11-01
A sufficiently large temperature anisotropy can sometimes drive various types of electromagnetic plasma micro-instabilities, which can play an important role in the dynamics of relativistic pair plasmas in space, astrophysics, and laboratory environments. Here, we provide a detailed description of the cyclotron instability of parallel propagating electromagnetic waves in relativistic pair plasmas on the basis of a relativistic anisotropic distribution function. Using plasma kinetic theory and particle-in-cell simulations, we study the influence of the relativistic temperature and the temperature anisotropy on the collective and noncollective modes of these plasmas. Growth rates and dispersion curves from the linear theory show a good agreement with simulations results.
Do non-relativistic neutrinos oscillate?
Akhmedov, Evgeny
2017-07-01
We study the question of whether oscillations between non-relativistic neutrinos or between relativistic and non-relativistic neutrinos are possible. The issues of neutrino production and propagation coherence and their impact on the above question are discussed in detail. It is demonstrated that no neutrino oscillations can occur when neutrinos that are non-relativistic in the laboratory frame are involved, except in a strongly mass-degenerate case. We also discuss how this analysis depends on the choice of the Lorentz frame. Our results are for the most part in agreement with Hinchliffe's rule.
Geometric Models of the Relativistic Harmonic Oscillator
Cotaescu, I I
1997-01-01
A family of relativistic geometric models is defined as a generalization of the actual anti-de Sitter (1+1) model of the relativistic harmonic oscillator. It is shown that all these models lead to the usual harmonic oscillator in the non-relativistic limit, even though their relativistic behavior is quite different. Among quantum models we find a set of models with countable energy spectra, and another one having only a finite number of energy levels and in addition a continuous spectrum.
Relativistic and non-relativistic solitons in plasmas
Barman, Satyendra Nath
This thesis entitled as "Relativistic and Non-relativistic Solitons in Plasmas" is the embodiment of a number of investigations related to the formation of ion-acoustic solitary waves in plasmas under various physical situations. The whole work of the thesis is devoted to the studies of solitary waves in cold and warm collisionless magnetized or unmagnetized plasmas with or without relativistic effect. To analyze the formation of solitary waves in all our models of plasmas, we have employed two established methods namely - reductive perturbation method to deduce the Korteweg-de Vries (KdV) equation, the solutions of which represent the important but near exact characteristic concepts of soliton-physics. Next, the pseudopotential method to deduce the energy integral with total nonlinearity in the coupling process for exact characteristic results of solitons has been incorporated. In Chapter 1, a brief description of plasma in nature and laboratory and its generation are outlined elegantly. The nonlinear differential equations to characterize solitary waves and the relevant but important methods of solutions have been mentioned in this chapter. The formation of solitary waves in unmagnetized and magnetized plasmas, and in relativistic plasmas has been described through mathematical entity. Applications of plasmas in different fields are also put forwarded briefly showing its importance. The study of plasmas as they naturally occur in the universe encompasses number of topics including sun's corona, solar wind, planetary magnetospheres, ionospheres, auroras, cosmic rays and radiation. The study of space weather to understand the universe, communications and the activities of weather satellites are some useful areas of space plasma physics. The surface cleaning, sterilization of food and medical appliances, killing of bacteria on various surfaces, destroying of viruses, fungi, spores and plasma coating in industrial instruments ( like computers) are some of the fields
潘彩娟
2009-01-01
假设位于黑洞赤道面上做圆形轨道运动的吸积盘是几何薄、光学厚的.利用光子追踪法计算在Kerr度规下的光子运动轨迹,通过数值计算研究薄吸积盘的相对论谱线轮廓及成像.在大角度观测时,吸积盘下表面的光子对谱线轮廓及成像的影响是显著的.%In the paper, it is programmed to get relativistic iron lines profile and flux images of accretion disks. The simplest case of a geometrically thin, optically thick accretion disk around a Kerr(spinning) black hole is focused.Ray tracing method is used in the trajectory of the photon in the Kerr metric, by numerical calculation to model theoretical emission line profiles and disk images. We get relativistic iron lines profile which is about flux varies as frequency varies and images of accretion disks. Viewing at large inclinations,because of contribution of the photons under the surface of the disk,the line profile appear double-peaked profile and the images are significantly changed.
Relativistic Corrections to the Bohr Model of the Atom
Kraft, David W.
1974-01-01
Presents a simple means for extending the Bohr model to include relativistic corrections using a derivation similar to that for the non-relativistic case, except that the relativistic expressions for mass and kinetic energy are employed. (Author/GS)
Autoionization resonances in the photoabsorption spectra of Fe{sup n+} iron ions
Konovalov, A. V., E-mail: alkonvit@yandex.ru; Ipatov, A. N., E-mail: andrei-ipatov@mail.ru [Peter the Great St. Petersburg State Polytechnic University (Russian Federation)
2016-11-15
The photoabsorption cross sections of a neutral iron atom, as well as positive Fe{sup +} and Fe{sup 2+} ions, are calculated in the relativistic random-phase approximation with exchange in the energy range 20–160 eV. The wavefunctions of the ground and excited states are calculated in the single-configuration Hartree–Fock–Dirac approximation. The resultant photoabsorption spectra are compared with experimental data and with the results of calculations based on the nonrelativistic spin-polarized version of the random-phase approximation with exchange. Series of autoionization resonance peaks, as well as giant autoionization resonance lines corresponding to discrete transitions 3p → 3d, are clearly observed in the photoabsorption cross sections. The conformity of the positions of calculated peaks of giant autoionization resonances with experimental data is substantially improved by taking into account additionally the correlation electron–electron interaction based on the model of the dynamic polarization potential.
Magnetogenesis through Relativistic Velocity Shear
Miller, Evan
Magnetic fields at all scales are prevalent in our universe. However, current cosmological models predict that initially the universe was bereft of large-scale fields. Standard magnetohydrodynamics (MHD) does not permit magnetogenesis; in the MHD Faraday's law, the change in magnetic field B depends on B itself. Thus if B is initially zero, it will remain zero for all time. A more accurate physical model is needed to explain the origins of the galactic-scale magnetic fields observed today. In this thesis, I explore two velocity-driven mechanisms for magnetogenesis in 2-fluid plasma. The first is a novel kinematic 'battery' arising from convection of vorticity. A coupling between thermal and plasma oscillations, this non-relativistic mechanism can operate in flows that are incompressible, quasi-neutral and barotropic. The second mechanism results from inclusion of thermal effects in relativistic shear flow instabilities. In such flows, parallel perturbations are ubiquitously unstable at small scales, with growth rates of order with the plasma frequency over a defined range of parameter-space. Of these two processes, instabilities seem far more likely to account for galactic magnetic fields. Stable kinematic effects will, at best, be comparable to an ideal Biermann battery, which is suspected to be orders of magnitude too weak to produce the observed galactic fields. On the other hand, instabilities grow until saturation is reached, a topic that has yet to be explored in detail on cosmological scales. In addition to investigating these magnetogenesis sources, I derive a general dispersion relation for three dimensional, warm, two species plasma with discontinuous shear flow. The mathematics of relativistic plasma, sheared-flow instability and the Biermann battery are also discussed.
Relativistic Plasma Polarizer: Impact of Temperature Anisotropy on Relativistic Transparency
Hazeltine, R. D.; Stark, David J.; Bhattacharjee, Chinmoy; Arefiev, Alexey V.; Toncian, Toma; Mahajan, S. M.
2015-11-01
3D particle-in-cell simulations demonstrate that the enhanced transparency of a relativistically hot plasma is sensitive to how the energy is partitioned between different degrees of freedom. We consider here the simplest problem: the propagation of a low amplitude pulse through a preformed relativistically hot anisotropic electron plasma to explore its intrinsic dielectric properties. We find that: 1) the critical density for propagation depends strongly on the pulse polarization, 2) two plasmas with the same density and average energy per electron can exhibit profoundly different responses to electromagnetic pulses, 3) the anisotropy-driven Weibel instability develops as expected; the timescales of the growth and back reaction (on anisotropy), however, are long enough that sufficient anisotropy persists for the entire duration of the simulation. This plasma can then function as a polarizer or a wave plate to dramatically alter the pulse polarization. This work was supported by the U.S. DOE Contract Nos. DE-FG02-04ER54742 and DE-AC05-06OR23100 (D. J. S.) and NNSA Contract No. DE-FC52-08NA28512.
On the relativistic anisotropic configurations
Shojai, F. [University of Tehran, Department of Physics, Tehran (Iran, Islamic Republic of); Institute for Research in Fundamental Sciences (IPM), Foundations of Physics Group, School of Physics, Tehran (Iran, Islamic Republic of); Kohandel, M. [Alzahra University, Department of Physics and Chemistry, Tehran (Iran, Islamic Republic of); Stepanian, A. [University of Tehran, Department of Physics, Tehran (Iran, Islamic Republic of)
2016-06-15
In this paper we study anisotropic spherical polytropes within the framework of general relativity. Using the anisotropic Tolman-Oppenheimer-Volkov equations, we explore the relativistic anisotropic Lane-Emden equations. We find how the anisotropic pressure affects the boundary conditions of these equations. Also we argue that the behavior of physical quantities near the center of star changes in the presence of anisotropy. For constant density, a class of exact solution is derived with the aid of a new ansatz and its physical properties are discussed. (orig.)
Simple waves in relativistic fluids.
Lyutikov, Maxim
2010-11-01
We consider the Riemann problem for relativistic flows of polytropic fluids and find relations for the flow characteristics. Evolution of physical quantities takes especially simple form for the case of cold magnetized plasmas. We find exact explicit analytical solutions for one-dimensional expansion of magnetized plasma into vacuum, valid for arbitrary magnetization. We also consider expansion into cold unmagnetized external medium both for stationary initial conditions and for initially moving plasma, as well as reflection of rarefaction wave from a wall. We also find self-similar structure of three-dimensional magnetized outflows into vacuum, valid close to the plasma-vacuum interface.
Observation of relativistic antihydrogen atoms
Blanford, Glenn Delfosse, Jr.
1997-09-01
An observation of relativistic antihydrogen atoms is reported in this dissertation. Experiment 862 at Fermi National Accelerator Laboratory observed antihydrogen atoms produced by the interaction of a circulating beam of high momentum (3 production is outlined within. The cross section corresponds to the process where a high momentum antiproton causes e+e/sp- pair creation near a nucleus with the e+ being captured by the antiproton. Antihydrogen is the first atom made exclusively of antimatter to be detected. The observation experiment's results are the first step towards an antihydrogen spectroscopy experiment which would measure the n = 2 Lamb shift and fine structure.
Einstein Toolkit for Relativistic Astrophysics
Collaborative Effort
2011-02-01
The Einstein Toolkit is a collection of software components and tools for simulating and analyzing general relativistic astrophysical systems. Such systems include gravitational wave space-times, collisions of compact objects such as black holes or neutron stars, accretion onto compact objects, core collapse supernovae and Gamma-Ray Bursts. The Einstein Toolkit builds on numerous software efforts in the numerical relativity community including CactusEinstein, Whisky, and Carpet. The Einstein Toolkit currently uses the Cactus Framework as the underlying computational infrastructure that provides large-scale parallelization, general computational components, and a model for collaborative, portable code development.
Density perturbations with relativistic thermodynamics
Maartens, R
1997-01-01
We investigate cosmological density perturbations in a covariant and gauge- invariant formalism, incorporating relativistic causal thermodynamics to give a self-consistent description. The gradient of density inhomogeneities splits covariantly into a scalar part, a rotational vector part that is determined by the vorticity, and a tensor part that describes the shape. We give the evolution equations for these parts in the general dissipative case. Causal thermodynamics gives evolution equations for viswcous stress and heat flux, which are coupled to the density perturbation equation and to the entropy and temperature perturbation equations. We give the full coupled system in the general dissipative case, and simplify the system in certain cases.
Thermodynamics of polarized relativistic matter
Kovtun, Pavel
2016-07-01
We give the free energy of equilibrium relativistic matter subject to external gravitational and electromagnetic fields, to one-derivative order in the gradients of the external fields. The free energy allows for a straightforward derivation of bound currents and bound momenta in equilibrium. At leading order, the energy-momentum tensor admits a simple expression in terms of the polarization tensor. Beyond the leading order, electric and magnetic polarization vectors are intrinsically ambiguous. The physical effects of polarization, such as the correlation between the magneto-vortically induced surface charge and the electro-vortically induced surface current, are not ambiguous.
Thermodynamics of polarized relativistic matter
Kovtun, Pavel
2016-01-01
We give the free energy of equilibrium relativistic matter subject to external gravitational and electromagnetic fields, to one-derivative order in the gradients of the external fields. The free energy allows for a straightforward derivation of bound currents and bound momenta in equilibrium. At leading order, the energy-momentum tensor admits a simple expression in terms of the polarization tensor. Beyond the leading order, electric and magnetic polarization vectors are intrinsically ambiguous. The physical effects of polarization, such as the correlation between the magneto-vortically induced surface charge and the electro-vortically induced surface current, are not ambiguous.
Relativistic solitons and superluminal signals
Maccari, Attilio [Technical Institute ' G. Cardano' , Piazza della Resistenza 1, Monterotondo, Rome 00015 (Italy)]. E-mail: solitone@yahoo.it
2005-02-01
Envelope solitons in the weakly nonlinear Klein-Gordon equation in 1 + 1 dimensions are investigated by the asymptotic perturbation (AP) method. Two different types of solitons are possible according to the properties of the dispersion relation. In the first case, solitons propagate with the group velocity (less than the light speed) of the carrier wave, on the contrary in the second case solitons always move with the group velocity of the carrier wave, but now this velocity is greater than the light speed. Superluminal signals are then possible in classical relativistic nonlinear field equations.
Margutti, R.; Milisavljevic, D.; Soderberg, A. M.; Sanders, N.; Chakraborti, S.; Kamble, A.; Drout, M.; Parrent, J.; Zauderer, A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Guidorzi, C. [Department of Physics and Earth Sciences, University of Ferrara, via Saragat 1, I-44122 Ferrara (Italy); Morsony, B. J. [Department of Astronomy, University of Wisconsin-Madison, 2535 Sterling Hall, 475 North Charter Street, Madison, WI 53706-1582 (United States); Ray, A. [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005 (India); Chomiuk, L. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)
2014-12-20
Deep, late-time X-ray observations of the relativistic, engine-driven, type Ic SN 2012ap allow us to probe the nearby environment of the explosion and reveal the unique properties of relativistic supernova explosions (SNe). We find that on a local scale of ∼0.01 pc the environment was shaped directly by the evolution of the progenitor star with a pre-explosion mass-loss rate of M-dot <5×10{sup −6} M{sub ⊙} yr{sup −1}, in line with gamma-ray bursts (GRBs) and the other relativistic SN 2009bb. Like sub-energetic GRBs, SN 2012ap is characterized by a bright radio emission and evidence for mildly relativistic ejecta. However, its late-time (δt ≈ 20 days) X-ray emission is ∼100 times fainter than the faintest sub-energetic GRB at the same epoch, with no evidence for late-time central engine activity. These results support theoretical proposals that link relativistic SNe like 2009bb and 2012ap with the weakest observed engine-driven explosions, where the jet barely fails to break out. Furthermore, our observations demonstrate that the difference between relativistic SNe and sub-energetic GRBs is intrinsic and not due to line-of-sight effects. This phenomenology can either be due to an intrinsically shorter-lived engine or to a more extended progenitor in relativistic SNe.
Theoretical Study of Spin Crossover in 30 Iron Complexes
Kepp, Kasper Planeta
2016-01-01
Spin crossover was studied in 30 iron complexes using density functional theory to quantify the direction and magnitude of dispersion, relativistic effects, zero-point energies, and vibrational entropy. Remarkably consistent entropy−enthalpy compensation was identified. Zero-point energies favor ...
Relativistic suppression of wave packet spreading.
Su, Q; Smetanko, B; Grobe, R
1998-03-30
We investigate numerically the solution of Dirac equation and analytically the Klein-Gordon equation and discuss the relativistic motion of an electron wave packet in the presence of an intense static electric field. In contrast to the predictions of the (non-relativistic) Schroedinger theory, the spreading rate in the field's polarization direction as well as in the transverse directions is reduced.
Magnetism and rotation in relativistic field theory
Mameda, Kazuya; Yamamoto, Arata
2016-09-01
We investigate the analogy between magnetism and rotation in relativistic theory. In nonrelativistic theory, the exact correspondence between magnetism and rotation is established in the presence of an external trapping potential. Based on this, we analyze relativistic rotation under external trapping potentials. A Landau-like quantization is obtained by considering an energy-dependent potential.
Relativistic heavy-ion physics: Experimental overview
Itzhak Tserruya
2003-04-01
The ﬁeld of relativistic heavy-ion physics is reviewed with emphasis on new results and highlights from the ﬁrst run of the relativistic heavy-ion collider at BNL and the 15 year research programme at the super proton synchrotron (SPS) at CERN and the AGS at BNL.
Physico-mathematical foundations of relativistic cosmology
Soares, Domingos
2013-01-01
I briefly present the foundations of relativistic cosmology, which are, General Relativity Theory and the Cosmological Principle. I discuss some relativistic models, namely, "Einstein static universe" and "Friedmann universes". The classical bibliographic references for the relevant tensorial demonstrations are indicated whenever necessary, although the calculations themselves are not shown.
Einstein Never Approved of Relativistic Mass
Hecht, Eugene
2009-01-01
During much of the 20th century it was widely believed that one of the significant insights of special relativity was "relativistic mass." Today there are two schools on that issue: the traditional view that embraces speed-dependent "relativistic mass," and the more modern position that rejects it, maintaining that there is only one mass and it's…
General relativistic Boltzmann equation, I: Covariant treatment
Debbasch, F.; van Leeuwen, W.A.
2009-01-01
This series of two articles aims at dissipating the rather dense haze existing in the present literature around the General Relativistic Boltzmann equation. In this first article, the general relativistic one-particle distribution function in phase space is defined as an average of delta functions.
Critique of Conventional Relativistic Quantum Mechanics.
Fanchi, John R.
1981-01-01
Following an historical sketch of the development of relativistic quantum mechanics, a discussion of the still unresolved difficulties of the currently accepted theories is presented. This review is designed to complement and update the discussion of relativistic quantum mechanics presented in many texts used in college physics courses. (Author/SK)
Lattice Boltzmann equation for relativistic quantum mechanics.
Succi, Sauro
2002-03-15
Relativistic versions of the quantum lattice Boltzmann equation are discussed. It is shown that the inclusion of nonlinear interactions requires the standard collision operator to be replaced by a pair of dynamic fields coupling to the relativistic wave function in a way which can be described by a multicomponent complex lattice Boltzmann equation.
Relativistic corrections to molecular dynamic dipole polarizabilities
Kirpekar, Sheela; Oddershede, Jens; Jensen, Hans Jørgen Aagaard
1995-01-01
Using response function methods we report calculations of the dynamic isotropic polarizability of SnH4 and PbH4 and of the relativistic corrections to it in the random phase approximation and at the correlated multiconfigurational linear response level of approximation. All relativistic corrections...
Probing relativistic effects in the central engine of AGN
Sanfrutos, M.; Miniutti, G.
2017-03-01
Active Galactic Nuclei (AGN) are perfect laboratories to check General Relativity (GR) effects by using Broad Line Region (BLR) clouds eclipses to probe the innermost regions of the accretion disk. A new relativistic X–ray spectral model for X–ray eclipses is introduced. First we present the different observables that are involved in X–ray eclipses, including the X–ray emitting regions size, the emissivity index, the cloud's column density, ionization, size and velocity, the black hole spin, and the system's inclination. Then we highlight some theoretical predictions on the observables by using XMM–Newton simulations, finding that absorption varies depending on the photons' energy range, being maximum when the approaching side of the X–ray–emitting region is covered. Finally, we fit our relativistic model to actual XMM–Newton data from a long observation of the NLS1 galaxy SWIFT J2127.4+5654, and compare our results with a previous work, in which we addressed the BLR cloud eclipse from a non–relativistic prespective.
Dynamic transition in supercritical iron.
Fomin, Yu D; Ryzhov, V N; Tsiok, E N; Brazhkin, V V; Trachenko, K
2014-11-26
Recent advance in understanding the supercritical state posits the existence of a new line above the critical point separating two physically distinct states of matter: rigid liquid and non-rigid gas-like fluid. The location of this line, the Frenkel line, remains unknown for important real systems. Here, we map the Frenkel line on the phase diagram of supercritical iron using molecular dynamics simulations. On the basis of our data, we propose a general recipe to locate the Frenkel line for any system, the recipe that importantly does not involve system-specific detailed calculations and relies on the knowledge of the melting line only. We further discuss the relationship between the Frenkel line and the metal-insulator transition in supercritical liquid metals. Our results enable predicting the state of supercritical iron in several conditions of interest. In particular, we predict that liquid iron in the Jupiter core is in the "rigid liquid" state and is highly conducting. We finally analyse the evolution of iron conductivity in the core of smaller planets such as Earth and Venus as well as exoplanets: as planets cool off, the supercritical core undergoes the transition to the rigid-liquid conducting state at the Frenkel line.
The curious time lags of PG 1244+026: Discovery of the iron K reverberation lag
Kara, E; Fabian, A C; Reynolds, C; Uttley, P
2013-01-01
High-frequency iron K reverberation lags, where the red wing of the line responds before the line centroid, are a robust signature of relativistic reflection off the inner accretion disc. In this letter, we report the discovery of the Fe K lag in PG 1244+026 from ~120 ks of data (1 orbit of the XMM-Newton telescope). The amplitude of the lag with respect to the continuum is 1000 s at a frequency of ~1e-4 Hz. We also find a possible frequency-dependence of the line: as we probe higher frequencies (i.e. shorter timescales from a smaller emitting region) the Fe K lag peaks at the red wing of the line, while at lower frequencies (from a larger emitting region) we see the dominant reflection lag from the rest frame line centroid. The mean energy spectrum shows a strong soft excess, though interestingly, there is no indication of a soft lag. Given that this source has radio emission and it has little reported correlated variability between the soft excess and the hard band, we explore one possible explanation in wh...
Filippo Cassarà
2013-03-01
Full Text Available Recent research addressed the main role of hepcidin in the regulation of iron metabolism. However, while this mechanism could be relevant in causing iron load in Thalassemia Intermedia and Sickle-Cell Anemia, its role in Thalassemia Major (TM is marginal. This is mainly due to the high impact of transfusional requirement into the severe increase of body iron. Moreover, the damage of iron load may be worsened by infections, as HCV hepatitis, or liver and endocrinological damage. One of the most relevant associations was found between splenectomy and increase of risk for mortality due,probably, to more severe iron load. These issues suggest as morbidity and mortality of this group of patients they do not depend only by our ability in controlling heart damage but even in preventing or treating particular infections and complications. This finding is supported by the impairment of survival curves in patients with complications different from heart damage. However, because, during recent years different direct and indirect methods to detect iron overload in patients affected by secondary hemochromatosis have been implemented, our ability to maintain under control iron load is significantly improved. Anyway, the future in iron load management remains to be able to have an iron load map of our body for targeting chelation and other medical treatment according to the single organ damage.
Relativistic electron beams above thunderclouds
M. Füllekrug
2011-08-01
Full Text Available Non-luminous relativistic electron beams above thunderclouds have been detected by the radio signals of low frequency ∼40–400 kHz which they radiate. The electron beams occur ∼2–9 ms after positive cloud-to-ground lightning discharges at heights between ∼22–72 km above thunderclouds. Intense positive lightning discharges can also cause sprites which occur either above or prior to the electron beam. One electron beam was detected without any luminous sprite which suggests that electron beams may also occur independently of sprites. Numerical simulations show that beams of electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of ∼7 MeV to transport a total charge of ∼−10 mC upwards. The impulsive current ∼3 × 10^{−3} Am^{−2} associated with relativistic electron beams above thunderclouds is directed downwards and needs to be considered as a novel element of the global atmospheric electric circuit.
Ponderomotive Acceleration by Relativistic Waves
Lau, Calvin; Yeh, Po-Chun; Luk, Onnie; McClenaghan, Joseph; Ebisuzaki, Toshikazu; Tajima, Toshiki
2014-01-01
In the extreme high intensity regime of electromagnetic (EM) waves in plasma, the acceleration process is found to be dominated by the ponderomotive acceleration (PA). While the wakefields driven by the ponderomotive force of the relativistic intensity EM waves are important, they may be overtaken by the PA itself in the extreme high intensity regime when the dimensionless vector potential $a_0$ of the EM waves far exceeds unity. The energy gain by this regime (in 1D) is shown to be (approximately) proportional to $a_0^2$. Before reaching this extreme regime, the coexistence of the PA and the wakefield acceleration (WA) is observed where the wave structures driven by the wakefields show the phenomenon of multiple and folded wave-breakings. Investigated are various signatures of the acceleration processes such as the dependence on the mass ratio for the energy gain as well as the energy spectral features. The relevance to high energy cosmic ray acceleration and to the relativistic laser acceleration is conside...
24-Hour Relativistic Bit Commitment
Verbanis, Ephanielle; Martin, Anthony; Houlmann, Raphaël; Boso, Gianluca; Bussières, Félix; Zbinden, Hugo
2016-09-01
Bit commitment is a fundamental cryptographic primitive in which a party wishes to commit a secret bit to another party. Perfect security between mistrustful parties is unfortunately impossible to achieve through the asynchronous exchange of classical and quantum messages. Perfect security can nonetheless be achieved if each party splits into two agents exchanging classical information at times and locations satisfying strict relativistic constraints. A relativistic multiround protocol to achieve this was previously proposed and used to implement a 2-millisecond commitment time. Much longer durations were initially thought to be insecure, but recent theoretical progress showed that this is not so. In this Letter, we report on the implementation of a 24-hour bit commitment solely based on timed high-speed optical communication and fast data processing, with all agents located within the city of Geneva. This duration is more than 6 orders of magnitude longer than before, and we argue that it could be extended to one year and allow much more flexibility on the locations of the agents. Our implementation offers a practical and viable solution for use in applications such as digital signatures, secure voting and honesty-preserving auctions.
Chaos and Maps in Relativistic Dynamical Systems
Horwitz, L P
1999-01-01
The basic work of Zaslavskii et al showed that the classical non-relativistic electromagnetically kicked oscillator can be cast into the form of an iterative map on the phase space; the resulting evolution contains a stochastic flow to unbounded energy. Subsequent studies have formulated the problem in terms of a relativistic charged particle in interaction with the electromagnetic field. We review the structure of the covariant Lorentz force used to study this problem. We show that the Lorentz force equation can be derived as well from the manifestly covariant mechanics of Stueckelberg in the presence of a standard Maxwell field, establishing a connection between these equations and mass shell constraints. We argue that these relativistic generalizations of the problem are intrinsically inaccurate due to an inconsistency in the structure of the relativistic Lorentz force, and show that a reformulation of the relativistic problem, permitting variations (classically) in both the particle mass and the effective...
Relativistic Particles in Clusters of Galaxies
Ensslin, T A
2002-01-01
A brief overview on the theory and observations of relativistic particle populations in clusters of galaxies is given. The following topics are addressed: (i) the diffuse relativistic electron population within the intra-cluster medium (ICM) as seen in the cluster wide radio halos and possibly also seen in the high energy X-ray and extreme ultraviolet excess emissions of some clusters, (ii) the observed confined relativistic electrons within fresh and old radio plasma and their connection to cluster radio relics at cluster merger shock waves, (iii) the relativistic proton population within the ICM, and its observable consequences (if it exists), and (iv) the confined relativistic proton population (if it exists) within radio plasma. The importance of upcoming, sensitive gamma-ray telescopes for this research area is highlighted.
Relativistic gas in a Schwarzschild metric
Kremer, Gilberto M
2013-01-01
A relativistic gas in a Schwarzschild metric is studied within the framework of a relativistic Boltzmann equation in the presence of gravitational fields, where Marle's model for the collision operator of the Boltzmann equation is employed. The transport coefficients of bulk and shear viscosities and thermal conductivity are determined from the Chapman-Enskog method. It is shown that the transport coefficients depend on the gravitational potential. Expressions for the transport coefficients in the presence of weak gravitational fields in the non-relativistic (low temperatures) and ultra-relativistic (high temperatures) limiting cases are given. Apart from the temperature gradient the heat flux has two relativistic terms. The first one, proposed by Eckart, is due to the inertia of energy and represents an isothermal heat flux when matter is accelerated. The other, suggested by Tolman, is proportional to the gravitational potential gradient and indicates that -- in the absence of an acceleration field -- a stat...
Relativistic recursion relations for transition matrix elements
Martínez y Romero, R P; Salas-Brito, A L
2004-01-01
We review some recent results on recursion relations which help evaluating arbitrary non-diagonal, radial hydrogenic matrix elements of $r^\\lambda$ and of $\\beta r^\\lambda$ ($\\beta$ a Dirac matrix) derived in the context of Dirac relativistic quantum mechanics. Similar recursion relations were derived some years ago by Blanchard in the non relativistic limit. Our approach is based on a generalization of the second hypervirial method previously employed in the non-relativistic Schr\\"odinger case. An extension of the relations to the case of two potentials in the so-called unshifted case, but using an arbitrary radial function instead of a power one, is also given. Several important results are obtained as special instances of our recurrence relations, such as a generalization to the relativistic case of the Pasternack-Sternheimer rule. Our results are useful in any atomic or molecular calculation which take into account relativistic corrections.
FERO (Finding Extreme Relativistic Objects: statistics of relativistic broad Fe K lines in AGN
A. L. Longinotti
2008-01-01
Full Text Available Las propiedades de las líneas de emisión Fe Kα ensanchadas relativísticamente en núcleos activos de galaxias (AGN son aún materia de debate en la comunidad. Los trabajos recientes parecen excluir que la línea ancha de Fe es un rasgo común en los AGN. Se presenta el análisis de una gran muestra de 157 observaciones de archivo del XMM-Newton de AGN radio callados. Este trabajo en curso es lo desarrollado desde lo reportado en Guainazzi et al. (2006.
Lattice Boltzmann model for resistive relativistic magnetohydrodynamics.
Mohseni, F; Mendoza, M; Succi, S; Herrmann, H J
2015-08-01
In this paper, we develop a lattice Boltzmann model for relativistic magnetohydrodynamics (MHD). Even though the model is derived for resistive MHD, it is shown that it is numerically robust even in the high conductivity (ideal MHD) limit. In order to validate the numerical method, test simulations are carried out for both ideal and resistive limits, namely the propagation of Alfvén waves in the ideal MHD and the evolution of current sheets in the resistive regime, where very good agreement is observed comparing to the analytical results. Additionally, two-dimensional magnetic reconnection driven by Kelvin-Helmholtz instability is studied and the effects of different parameters on the reconnection rate are investigated. It is shown that the density ratio has a negligible effect on the magnetic reconnection rate, while an increase in shear velocity decreases the reconnection rate. Additionally, it is found that the reconnection rate is proportional to σ-1/2, σ being the conductivity, which is in agreement with the scaling law of the Sweet-Parker model. Finally, the numerical model is used to study the magnetic reconnection in a stellar flare. Three-dimensional simulation suggests that the reconnection between the background and flux rope magnetic lines in a stellar flare can take place as a result of a shear velocity in the photosphere.
La relativeca tempo -- II / The relativistic time -- II
Paiva, F M
2011-01-01
The theory of relativity showed that several Newtonian ideas about spacetime are imperfect. We present here some relativistic concepts related to these ideas: simultaneity of events and synchronization of clocks (both along a line in the space frame), gravitational Doppler effect, and time travel. --------- La relativeca teorio montris ke pluraj Newtonaj ideoj pri la spacotempo estas malperfektaj. Tie cxi ni prezentas kelkajn relativecajn konceptojn iel rilatajn al tiuj ideoj: samtempecon de eventoj kaj sinkronon de horlogxoj (ambaux laux linio en la spaca reto), gravitan Doppleran efikon, kaj vojagxon kun reveno al estinto.
Iron refractory iron deficiency anemia
De Falco, Luigia; Sanchez, Mayka; Silvestri, Laura; Kannengiesser, Caroline; Muckenthaler, Martina U; Iolascon, Achille; Gouya, Laurent; Camaschella, Clara; Beaumont, Carole
2013-01-01
Iron refractory iron deficiency anemia is a hereditary recessive anemia due to a defect in the TMPRSS6 gene encoding Matriptase-2. This protein is a transmembrane serine protease that plays an essential role in down-regulating hepcidin, the key regulator of iron homeostasis. Hallmarks of this disease are microcytic hypochromic anemia, low transferrin saturation and normal/high serum hepcidin values. The anemia appears in the post-natal period, although in some cases it is only diagnosed in ad...
Carvalho, FS; de Medeiros, IA; Antunes, H.
2017-01-01
Iron deficiency is the most common cause of anemia in children with inflammatory bowel disease, although the real prevalence is unknown. Intravenous iron is suggested as the first line treatment. This study aims to determine the prevalence of iron deficiency anemia in children with inflammatory bowel disease followed in a Pediatric Gastroenterology Unit of a tertiary center and to evaluate this unit's experience with intravenous iron. info:eu-repo/semantics/publishedVersion
Sulaiman, Ghassan M; Tawfeeq, Amer T; Naji, Amal S
2017-08-21
Magnetic iron oxide nanoparticles (MNPs) were synthesized using Albizia adianthifolia leaf extract as reducing and protecting agent. Colour changing, UV-Vis spectrum, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) confirmed the biosynthesis and characterization of MNPs. The XRD pattern revealed that MNPs are crystalline in nature. FT-IR spectral analysis showed that MNPs was capped with plant constituents. From SEM analysis, the MNPs were generally found to be spherical in shape and the size was ranged 32-100 nm. Free radical scavenging potentials of the MNPs against DPPH were confirmed based on its stable anti-oxidant effects. The synthesized MNPs were used to capture Staphylococcus aureus under the magnetic field effect. Further, it was observed that the MNPs are able to exert cytotoxic effect towards human breast (AMJ-13) and (MCF-7) cancer cells. The anti-proliferative effect of this treatment is due to cell death and inducing apoptosis. Mitochondrial membrane potential, acridine orange-propidium iodide staining assays as well as single cell and DNA gel electrophoresis analyses indicated that MNPs induce cell death only by apoptosis. The findings of present study suggest that the MNPs might be used for medicinal applications particularly for cancer therapeutics.
Ahmad Gholami
2015-01-01
Full Text Available Superparamagnetic iron oxide nanoparticles (SPION have been widely used in medicine for magnetic resonance imaging, hyperthermia, and drug delivery applications. The effect of SPION on animal cells has been a controversial issue on which there are many contradictions. This study focused on preparation of SPION with novel biocompatible coatings, their characterization, and cytotoxicity evaluation. An amino acid (glycine and two novel lipo-amino acids (2 amino-hexanoic acid and 2 amino-hexadecanoic acid coated magnetic nanoparticles were characterized by various physicochemical means such as X-ray diffraction (XRD, transmission electron microscopy (TEM, vibrating sample magnetometry (VSM, differential scanning calorimetry (DSC, and infrared spectroscopy (FT-IR. The cytotoxicity profile of the synthesized nanoparticles on Hep-G2 cells as measured by MTT assay showed the nanoparticles are nontoxic and the cell growth is promoted by SPION. Moreover, lipoamino acid coating SPION appear more beneficial than the other ones. By increasing concentration of SPION, growth enhancing impact will attenuate and toxicity will appear. Although the aggregation of SPION can affect the results, the gradual delivery of ferric/ferrous ions into cells is the main cause of this growth promotion effect. Conclusively, this study shows that lipoamino acid coating SPION can be used for various biomedical purposes.
1996-01-01
Cast iron offers the design engineer a low-cost, high-strength material that can be easily melted and poured into a wide variety of useful, and sometimes complex, shapes. This latest handbook from ASM covers the entire spectrum of one of the most widely used and versatile of all engineered materials. The reader will find the basic, but vital, information on metallurgy, solidification characteristics, and properties. Extensive reviews are presented on the low-alloy gray, ductile, compacted graphite, and malleable irons. New and expanded material has been added covering high-alloy white irons used for abrasion resistance and high-alloy graphitic irons for heat and corrosion resistance. Also discussed are melting furnaces and foundry practices such as melting, inoculation, alloying, pouring, gating and rising, and molding. Heat treating practices including stress relieving, annealing, normalizing, hardening and tempering, autempering (of ductile irons), and surface-hardening treatments are covered, too. ASM Spec...
张俊平
2011-01-01
In the construction of the iron tower foundation power transmission lines,the paper indicates some features,including the weak geological conditions in the foundation,the tough tasks for the pier construction,and the long construction period,the paper introduces the difficulties and features of the crossing pier foundation construction of the power transmission lines,and adopts the effective measures in the cooling cycle water pipe,the temperature checking,and the surface maintenance of the concrete internal apparatus,and achieves satisfactory effects.%针对输电线路铁塔基础施工中,大量基础存在地质条件差、承台基础施工方量大、施工周期长等特点,详细介绍了输电线路大跨越大承台基础施工的难点、特点,在混凝土内部设置冷却循环水管及温度检测、表面养护等技术方面采取了有效的措施,并取得了满意的效果。
Relativistic Electrons in Electric Discharges
Cinar, Deniz
discharges as the source. The “Atmosphere-Space Interactions Monitor” (ASIM) for the International Space Station in 2016, led by DTU Space, and the French microsatellite TARANIS, also with launch in 2016, will identify with certainty the source of TGFs. In preparation for the missions, the Ph.D. project has...... developed a Monte Carlo module of a simulation code to model the formation of avalanches of electrons accelerated to relativistic energies, and the generation of bremsstrahlung through interactions with the neutral atmosphere. The code will be used in the analysis of data from the two space missions. We...... scattering. However, we only explored the properties of the complete number of photons reaching space, not the distribution at speci_c locations as in the case of a satellite. With this reservation we conclude that it is not possible to deduce much information from a satellite measurement of the photons...
Real vs. simulated relativistic jets
Gómez, J L; Agudo, I; Marscher, A P; Jorstad, S G; Aloy, M A
2005-01-01
Intensive VLBI monitoring programs of jets in AGN are showing the existence of intricate emission patterns, such as upstream motions or slow moving and quasi-stationary componentes trailing superluminal features. Relativistic hydrodynamic and emission simulations of jets are in very good agreement with these observations, proving as a powerful tool for the understanding of the physical processes taking place in the jets of AGN, microquasars and GRBs. These simulations show that the variability of the jet emission is the result of a complex combination of phase motions, viewing angle selection effects, and non-linear interactions between perturbations and the underlying jet and/or ambient medium. Both observations and simulations suggest that shock-in-jet models may be an overly simplistic idealization when interpreting the emission structure observed in actual jets.
Causal categories: relativistically interacting processes
Coecke, Bob
2011-01-01
A symmetric monoidal category naturally arises as the mathematical structure that organizes physical systems, processes, and composition thereof, both sequentially and in parallel. This structure admits a purely graphical calculus. This paper is concerned with the encoding of a fixed causal structure within a symmetric monoidal category: causal dependencies will correspond to topological connectedness in the graphical language. We show that correlations, either classical or quantum, force terminality of the tensor unit. We also show that well-definedness of the concept of a global state forces the monoidal product to be only partially defined, which in turn results in a relativistic covariance theorem. Except for these assumptions, at no stage do we assume anything more than purely compositional symmetric-monoidal categorical structure. We cast these two structural results in terms of a mathematical entity, which we call a `causal category'. We provide methods of constructing causal categories, and we study t...
Relativistic effects and quasipotential equations
Ramalho, G; Peña, M T
2002-01-01
We compare the scattering amplitude resulting from the several quasipotential equations for scalar particles. We consider the Blankenbecler-Sugar, Spectator, Thompson, Erkelenz-Holinde and Equal-Time equations, which were solved numerically without decomposition into partial waves. We analyze both negative-energy state components of the propagators and retardation effects. We found that the scattering solutions of the Spectator and the Equal-Time equations are very close to the nonrelativistic solution even at high energies. The overall relativistic effect increases with the energy. The width of the band for the relative uncertainty in the real part of the scattering $T$ matrix, due to different dynamical equations, is largest for backward-scattering angles where it can be as large as 40%.
Relativistic heavy-ion collisions
Bhalerao, Rajeev S
2014-01-01
The field of relativistic heavy-ion collisions is introduced to the high-energy physics students with no prior knowledge in this area. The emphasis is on the two most important observables, namely the azimuthal collective flow and jet quenching, and on the role fluid dynamics plays in the interpretation of the data. Other important observables described briefly are constituent quark number scaling, ratios of particle abundances, strangeness enhancement, and sequential melting of heavy quarkonia. Comparison is made of some of the basic heavy-ion results obtained at LHC with those obtained at RHIC. Initial findings at LHC which seem to be in apparent conflict with the accumulated RHIC data are highlighted.
General relativity and relativistic astrophysics
Mukhopadhyay, Banibrata
2016-01-01
Einstein established the theory of general relativity and the corresponding field equation in 1915 and its vacuum solutions were obtained by Schwarzschild and Kerr for, respectively, static and rotating black holes, in 1916 and 1963, respectively. They are, however, still playing an indispensable role, even after 100 years of their original discovery, to explain high energy astrophysical phenomena. Application of the solutions of Einstein's equation to resolve astrophysical phenomena has formed an important branch, namely relativistic astrophysics. I devote this article to enlightening some of the current astrophysical problems based on general relativity. However, there seem to be some issues with regard to explaining certain astrophysical phenomena based on Einstein's theory alone. I show that Einstein's theory and its modified form, both are necessary to explain modern astrophysical processes, in particular, those related to compact objects.
In search of relativistic time
Lachieze-Rey, Marc
2013-01-01
This paper explores the status of some notions which are usually associated to time, like datations, chronology, durations, causality, cosmic time and time functions in the Einsteinian relativistic theories. It shows how, even if some of these notions do exist in the theory or for some particular solution of it, they appear usually in mutual conflict: they cannot be synthesized coherently, and this is interpreted as the impossibility to construct a common entity which could be called time. This contrasts with the case in Newtonian physics where such a synthesis precisely constitutes Newtonian time. After an illustration by comparing the status of time in Einsteinian physics with that of the vertical direction in Newtonian physics, I will conclude that there is no pertinent notion of time in Einsteinian theories.
Playing relativistic billiards beyond graphene
Sadurni, E [Institut fuer Quantenphysik, Ulm Universitaet, Albert-Einstein Allee 11, 89081 Ulm (Germany); Seligman, T H [Centro Internacional de Ciencias A.C., Apartado Postal 6-101 C.P. 62131 Cuernavaca, Mor. (Mexico); Mortessagne, F, E-mail: esadurni@uni-ulm.d, E-mail: seligman@fis.unam.m, E-mail: fabrice.mortessagne@unice.f [Laboratoire de Physique de la Matiere Condensee, Universite de Nice-Sophia Antipolis, CNRS, UMR 6622 Parc Valrose, 06108 Nice cedex 2 (France)
2010-05-15
The possibility of using hexagonal structures in general, and graphene in particular, to emulate the Dirac equation is the topic under consideration here. We show that Dirac oscillators with or without rest mass can be emulated by distorting a tight-binding model on a hexagonal structure. In the quest to make a toy model for such relativistic equations, we first show that a hexagonal lattice of attractive potential wells would be a good candidate. Firstly, we consider the corresponding one-dimensional (1D) model giving rise to a 1D Dirac oscillator and then construct explicitly the deformations needed in the 2D case. Finally, we discuss how such a model can be implemented as an electromagnetic billiard using arrays of dielectric resonators between two conducting plates that ensure evanescent modes outside the resonators for transversal electric modes, and we describe a feasible experimental setup.
Playing relativistic billiards beyond graphene
Sadurní, E.; Seligman, T. H.; Mortessagne, F.
2010-05-01
The possibility of using hexagonal structures in general, and graphene in particular, to emulate the Dirac equation is the topic under consideration here. We show that Dirac oscillators with or without rest mass can be emulated by distorting a tight-binding model on a hexagonal structure. In the quest to make a toy model for such relativistic equations, we first show that a hexagonal lattice of attractive potential wells would be a good candidate. Firstly, we consider the corresponding one-dimensional (1D) model giving rise to a 1D Dirac oscillator and then construct explicitly the deformations needed in the 2D case. Finally, we discuss how such a model can be implemented as an electromagnetic billiard using arrays of dielectric resonators between two conducting plates that ensure evanescent modes outside the resonators for transversal electric modes, and we describe a feasible experimental setup.
Playing relativistic billiards beyond graphene
Sadurni, Emerson; Mortessagne, Fabrice
2010-01-01
The possibility of using hexagonal structures in general and graphene in particular to emulate the Dirac equation is the basis of our considerations. We show that Dirac oscillators with or without restmass can be emulated by distorting a tight binding model on a hexagonal structure. In a quest to make a toy model for such relativistic equations we first show that a hexagonal lattice of attractive potential wells would be a good candidate. First we consider the corresponding one-dimensional model giving rise to a one-dimensional Dirac oscillator, and then construct explicitly the deformations needed in the two-dimensional case. Finally we discuss, how such a model can be implemented as an electromagnetic billiard using arrays of dielectric resonators between two conducting plates that ensure evanescent modes outside the resonators for transversal electric modes, and describe an appropriate experimental setup.
Relativistic Kinetic Theory: An Introduction
Sarbach, Olivier
2013-01-01
We present a brief introduction to the relativistic kinetic theory of gases with emphasis on the underlying geometric and Hamiltonian structure of the theory. Our formalism starts with a discussion on the tangent bundle of a Lorentzian manifold of arbitrary dimension. Next, we introduce the Poincare one-form on this bundle, from which the symplectic form and a volume form are constructed. Then, we define an appropriate Hamiltonian on the bundle which, together with the symplectic form yields the Liouville vector field. The corresponding flow, when projected onto the base manifold, generates geodesic motion. Whenever the flow is restricted to energy surfaces corresponding to a negative value of the Hamiltonian, its projection describes a family of future-directed timelike geodesics. A collisionless gas is described by a distribution function on such an energy surface, satisfying the Liouville equation. Fibre integrals of the distribution function determine the particle current density and the stress-energy ten...
Some Surprises in Relativistic Gravity
Santos, N O
2016-01-01
General Relativity has had tremendous success both on the theoretical and the experimental fronts for over a century now. However, the contents of the theory are far from exhausted. Only very recently, with the detection of gravitational waves from colliding black holes, we have started probing the behavior of gravity in the strongly non-linear regime. Even today, the studies of black holes keep revealing more and more paradoxes and bizarre results. In this paper, inspired by David Hilbert's startling observation, we show that, contrary to the conventional wisdom, a freely falling test particle feels gravitational repulsion by a black hole as seen by the asymptotic observer. We dig deeper into this surprising behavior of relativistic gravity and offer some explanations.
Thermodynamic Laws and Equipartition Theorem in Relativistic Brownian Motion
Koide, T.; Kodama, T.
2011-01-01
We extend the stochastic energetics to a relativistic system. The thermodynamic laws and equipartition theorem are discussed for a relativistic Brownian particle and the first and the second law of thermodynamics in this formalism are derived. The relation between the relativistic equipartition relation and the rate of heat transfer is discussed in the relativistic case together with the nature of the noise term.
Thermodynamic laws and equipartition theorem in relativistic Brownian motion.
Koide, T; Kodama, T
2011-06-01
We extend the stochastic energetics to a relativistic system. The thermodynamic laws and equipartition theorem are discussed for a relativistic Brownian particle and the first and the second law of thermodynamics in this formalism are derived. The relation between the relativistic equipartition relation and the rate of heat transfer is discussed in the relativistic case together with the nature of the noise term.
A Long Look at MCG-5-23-16 with NuSTAR. I. Relativistic Reflection and Coronal Properties
Zoghbi, Abderahmen; Matt, G.; Miller, J. M.; Lohfink, A. M.; Walton, D. J.; Ballantyne, D. R.; Garcia, J. A.; Stern, D.; Koss, M. J.; Farrah, D.;
2017-01-01
MCG-5-23-16 was targeted in early 2015 with a half mega-second observing campaign using NuSTAR. Here we present the spectral analysis of these data sets along with an earlier observation and study the relativistic reflection and the primary coronal source. The data show strong reflection features in the form of both narrow and broad iron lines plus a Compton reflection hump. A cutoff energy is significantly detected in all exposures. The shape of the reflection spectrum does not change in the two years spanned by the observations, suggesting a stable geometry. A strong positive correlation is found between the cutoff energy and both the hard X-ray flux and spectral index. The measurements imply that the coronal plasma is not at the runaway electron-positron pair limit, and instead contains mostly electrons. The observed variability in the coronal properties is driven by a variable optical depth. A constant heating-to-cooling ratio is measured, implying that there is a feedback mechanism in which a significant fraction of the photons cooling the corona are due to reprocessed hard X-rays.
Magnetic study of iron sorbitol
Lazaro, F.J. E-mail: osoro@posta.unizar.es; Larrea, A.; Abadia, A.R.; Romero, M.S
2002-09-01
A magnetic study of iron sorbitol, an iron-containing drug to treat the iron deficiency anemia is presented. Transmission electron microscopy reveals that the system contains nanometric particles with an average diameter of 3 nm whose composition is close to two-line ferrihydrite. The characterisation by magnetisation and AC susceptibility measurements indicates superparamagnetic behaviour with progressive magnetic blocking starting at 8 K. The quantitative analysis of the magnetic results indicates that the system consists of an assembly of very small magnetic moments, presumably originated by spin uncompensation of the antiferromagnetic nanoparticles, with Arrhenius type magnetic dynamics.
Holographic Aspects of a Relativistic Nonconformal Theory
Chanyong Park
2013-01-01
Full Text Available We study a general D-dimensional Schwarzschild-type black brane solution of the Einstein-dilaton theory and derive, by using the holographic renormalization, its thermodynamics consistent with the geometric results. Using the membrane paradigm, we calculate the several hydrodynamic transport coefficients and compare them with the results obtained by the Kubo formula, which shows the self-consistency of the gauge/gravity duality in the relativistic nonconformal theory. In order to understand more about the relativistic non-conformal theory, we further investigate the binding energy, drag force, and holographic entanglement entropy of the relativistic non-conformal theory.
Relativistic MHD with Adaptive Mesh Refinement
Anderson, M; Liebling, S L; Neilsen, D; Anderson, Matthew; Hirschmann, Eric; Liebling, Steven L.; Neilsen, David
2006-01-01
We solve the relativistic magnetohydrodynamics (MHD) equations using a finite difference Convex ENO method (CENO) in 3+1 dimensions within a distributed parallel adaptive mesh refinement (AMR) infrastructure. In flat space we examine a Balsara blast wave problem along with a spherical blast wave and a relativistic rotor test both with unigrid and AMR simulations. The AMR simulations substantially improve performance while reproducing the resolution equivalent unigrid simulation results. We also investigate the impact of hyperbolic divergence cleaning for the spherical blast wave and relativistic rotor. We include unigrid and mesh refinement parallel performance measurements for the spherical blast wave.
Relativistic Electron Experiment for the Undergraduate Laboratory
Marvel, Robert E
2011-01-01
We have developed an undergraduate laboratory experiment to make independent measurements of the momentum and kinetic energy of relativistic electrons from a \\beta -source. The momentum measurements are made with a magnetic spectrometer and a silicon surface-barrier detector is used to measure the kinetic energy. A plot of the kinetic energy as a function of momentum compared to the classical and relativistic predictions clearly shows the relativistic nature of the electrons. Accurate values for the rest mass of the electron and the speed of light are also extracted from the data.
DYNAMICS OF RELATIVISTIC FLUID FOR COMPRESSIBLE GAS
无
2011-01-01
In this paper the relativistic fluid dynamics for compressible gas is studied.We show that the strict convexity of the negative thermodynamical entropy preserves invariant under the Lorentz transformation if and only if the local speed of sound in this gas is strictly less than that of light in the vacuum.A symmetric form for the equations of relativistic hydrodynamics is presented,and thus the local classical solutions to these equations can be deduced.At last,the non-relativistic limits of these local cla...
Pireaux, S
2008-01-01
The Relativistic Motion Integrator (RMI) consists in integrating numerically the EXACT relativistic equations of motion, with respect to the appropriate gravitational metric, instead of Newtonian equations plus relativistic corrections. The aim of the present paper is to validate the method, and to illustrate how RMI can be used for space missions to produce relativistic ephemerides of satellites. Indeed, nowadays, relativistic effects have to be taken into account, and comparing a RMI ephemeris with a classical keplerian one helps to quantify such effects. LISA is a relevant example to use RMI. This mission is an interferometer formed by three spacecraft which aims at the detection of gravitational waves. Precise ephemerides of LISA spacecraft are needed not only for the sake of the orbitography but also to compute the photon flight time in laser links between spacecraft, required in LISA data pre-processing in order to reach the gravitational wave detection level. Relativistic effects in LISA orbitography n...
Shtykovsky, A. E.; Lutovinov, A. A.; Arefiev, V. A.; Molkov, S. V.; Tsygankov, S. S.; Revnivtsev, M. G.
2017-03-01
We present the results of the spectral and timing analysis of the X-ray pulsar LMC X-4 based on data from the NuSTAR observatory in the broad X-ray energy range 3-79 keV. Along with a detailed analysis of the source's averaged spectrum, high-precision spectra corresponding to different phases of the neutron star spin cycle have been obtained for the first time. The Comptonization model is shown to describe best the source's spectrum, and the evolution of its parameters as a function of the pulse phase has been traced. For all spectra (the averaged and phase-resolved ones) in the energy range 5-55 keV we have searched for the cyclotron absorption line. The derived upper limit on the optical depth of the cyclotron line τ 0.15 (3 σ) points to the absence of this feature in the given energy range, which provides a constraint on the magnetic field of the neutron star: B 6.5 × 1012 G. The latter constraint is consistent with the magnetic field estimate obtained by analyzing the pulsar's power spectrum, B ≅ 3 × 1013 G. Based on our analysis of the phase-resolved spectra, we have determined the delay between the emission peaks and the equivalent width of the fluorescent iron line. This delay depends on the orbital phase and is apparently associated with the travel time of photons between the emitting regions in the vicinity of the neutron star and the region where the flux is reflected (presumably in the inflowing stream or at the place of interaction between the stream and the outer edge of the accretion disk).
Radiation of Relativistic Particles in a Quasi-Homogeneous Magnetic Field
Epp, V
2016-01-01
Spectrum of radiation of a relativistic particle moving in a nonhomogeneous magnetic field is considered. The spectrum depends on the pitch-angle $\\alpha$ between the velocity direction and a line tangent to the field line. In case of very small $\\alpha$ the particle generates so-called curvature radiation, in an intermediate case undulator-kind radiation is produced. In this paper we present the calculations of radiation properties in a case when both curvature and undulator radiation is observed.
谢文玲; 周顺勇
2015-01-01
The characteristic point, characteristic curves and phase region in the iron-carbon alloy phase diagram were classified into three, three allotropic transformation, three horizontal lines and three solubility curve group by classification method. On this basis, phase diagram analysis was easy. First of all finding Fe3 C and marking out the L phase, then marking δ phase, a phase and γ phase according the iron’s allotropic transformation, finally, using the method of " left phase and right phase", the two-phase region can be rapidly annotated. This method makes the phase diagram more rational in teaching and learning and it has better auxiliary function for the analysis of the crystallization process of the iron carbon alloy.%采用归类法，将铁碳合金相图中的特性点和特性线分为同素异构转变、三条水平线和三条溶解度曲线三组综合分析，相区分析建立在特性点和特性线的基础上，首先找到Fe3 C相并标注出L相，再根据纯铁的同素异构转变标注出δ相、γ相和a相后，采用“左侧相+右侧相”的方法就可迅速标注出双相。该方法使相图在教与学中更具条理性，对于后面铁碳合金结晶过程分析起到较好的辅助作用。
Ahmad, D.; Park, I.; Kim, G.C.; Lee, J.H. [Department of Physics, Pusan National University, Busan 609-735 (Korea, Republic of); Ren, Z.-A. [National Laboratory for Superconductivity, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190 (China); Kim, Y.C., E-mail: yckim@pusan.ac.k [Department of Physics, Pusan National University, Busan 609-735 (Korea, Republic of)
2009-10-15
The irreversibility line and flux pinning properties of high-T{sub c} superconductor SmFeAsO{sub 0.85} were studied using DC magnetization data. Polycrystalline SmFeAsO{sub 0.85} was prepared in a high pressure synthesis apparatus under the pressure of 6 GPa. The results of DC susceptibility showed the superconducting transition at about 55 K. A critical current density J{sub c}(B) was calculated using Bean's critical state model. At low temperatures (<=20 K), J{sub c}(B) showed a relatively high value with weak dependence on an applied magnetic field. At higher temperatures, a stronger dependence of the magnetic field was observed, which resulted from decrease in a critical current density probably due to the flux creep effect. The irreversibility line (IL) agreed well with the flux creep theory of Matsushita et al. A comparison of normalized pinning force density with the theoretical models showed that the irreversible behavior in SmFeAsO{sub 0.85} is dominated mainly by normal point pinning (deltaT{sub c}) and surface pinning mechanisms.
Mashonkina, L; Shi, J -R; Korn, A J; Grupp, F
2011-01-01
A comprehensive model atom for Fe with more than 3000 energy levels is presented. As a test and first application of this model atom, Fe abundances are determined for the Sun and five stars with well determined stellar parameters and high-quality observed spectra. Non-LTE leads to systematically depleted total absorption in the Fe I lines and to positive abundance corrections in agreement with the previous studies, however, the magnitude of non-LTE effect is smaller compared to the earlier results. Non-LTE corrections do not exceed 0.1 dex for the solar metallicity and mildly metal-deficient stars, and they vary within 0.21 dex and 0.35 dex in the very metal-poor stars HD 84937 and HD 122563, respectively, depending on the assumed efficiency of collisions with hydrogen atoms. Based on the analysis of the Fe I/Fe II ionization equilibrium in these two stars, we recommend to apply the Drawin formalism in non-LTE studies of Fe with a scaling factor of 0.1. For the Fe II lines, non-LTE corrections do not exceed 0...
Relativistic elastic differential cross sections for equal mass nuclei
C.M. Werneth
2015-10-01
Full Text Available The effects of relativistic kinematics are studied for nuclear collisions of equal mass nuclei. It is found that the relativistic and non-relativistic elastic scattering amplitudes are nearly indistinguishable, and, hence, the relativistic and non-relativistic differential cross sections become indistinguishable. These results are explained by analyzing the Lippmann–Schwinger equation with the first order optical potential that was employed in the calculation.
Relativistic elastic differential cross sections for equal mass nuclei
Werneth, C.M., E-mail: charles.m.werneth@nasa.gov [NASA Langley Research Center, 2 West Reid Street, Hampton, VA 23681 (United States); Maung, K.M.; Ford, W.P. [The University of Southern Mississippi, 118 College Drive, Box 5046, Hattiesburg, MS 39406 (United States)
2015-10-07
The effects of relativistic kinematics are studied for nuclear collisions of equal mass nuclei. It is found that the relativistic and non-relativistic elastic scattering amplitudes are nearly indistinguishable, and, hence, the relativistic and non-relativistic differential cross sections become indistinguishable. These results are explained by analyzing the Lippmann–Schwinger equation with the first order optical potential that was employed in the calculation.
Artru, X. [Inst. de Physique Nucleaire, Lyon-1 Univ., 69 - Villeurbanne (France); Collaboration: IPN-Lyon, IRMM (Gell), LURE (Orsay); Collaboration: IPN-Lyon, LAL and IEF (Orsay), HIP (Helsinki), INFN (Frascati, Milan)
1998-12-31
We have studied different effects related to electromagnetic interaction of relativistic electrons in matter and investigated their use in beam profile measurements. (authors) 4 refs. Short communication
Plasmoids in relativistic reconnection, from birth to adulthood: first they grow, then they go
Sironi, Lorenzo; Giannios, Dimitrios; Petropoulou, Maria
2016-10-01
Blobs, or quasi-spherical emission regions containing relativistic particles and magnetic fields, are often assumed ad hoc in emission models of relativistic astrophysical jets, yet their physical origin is still not well understood. Here, we employ a suite of large-scale 2D particle-in-cell simulations in electron-positron plasmas to demonstrate that relativistic magnetic reconnection can naturally account for the formation of quasi-spherical plasmoids filled with high-energy particles and magnetic fields. Our simulations extend to unprecedentedly long temporal and spatial scales, so we can capture the asymptotic physics independently of the initial setup. We characterize the properties of the plasmoids, continuously generated as a self-consistent by-product of the reconnection process: they are in rough energy equipartition between particles and magnetic fields; the upper energy cutoff of the plasmoid particle spectrum is proportional to the plasmoid width w, corresponding to a Larmor radius ˜0.2 w; the plasmoids grow in size at ˜0.1 of the speed of light, with most of the growth happening while they are still non-relativistic (`first they grow'); their growth is suppressed once they get accelerated to relativistic speeds by the field line tension, up to the Alfvén speed (`then they go'). The largest plasmoids reach a width wmax ˜ 0.2 L independently of the system length L, they have nearly isotropic particle distributions and contain the highest energy particles, whose Larmor radius is ˜0.03 L. The latter can be regarded as the Hillas criterion for relativistic reconnection. We briefly discuss the implications of our results for the high-energy emission from relativistic jets and pulsar winds.
Clumps in large scale relativistic jets
Tavecchio, F; Celotti, A
2003-01-01
The relatively intense X-ray emission from large scale (tens to hundreds kpc) jets discovered with Chandra likely implies that jets (at least in powerful quasars) are still relativistic at that distances from the active nucleus. In this case the emission is due to Compton scattering off seed photons provided by the Cosmic Microwave Background, and this on one hand permits to have magnetic fields close to equipartition with the emitting particles, and on the other hand minimizes the requirements about the total power carried by the jet. The emission comes from compact (kpc scale) knots, and we here investigate what we can predict about the possible emission between the bright knots. This is motivated by the fact that bulk relativistic motion makes Compton scattering off the CMB photons efficient even when electrons are cold or mildly relativistic in the comoving frame. This implies relatively long cooling times, dominated by adiabatic losses. Therefore the relativistically moving plasma can emit, by Compton sc...
General relativistic corrections and non-Gaussianity
Villa, Eleonora; Matarrese, Sabino
2014-01-01
General relativistic cosmology cannot be reduced to linear relativistic perturbations superposed on an isotropic and homogeneous (Friedmann-Robertson-Walker) background, even though such a simple scheme has been successfully applied to analyse a large variety of phenomena (such as Cosmic Microwave Background primary anisotropies, matter clustering on large scales, weak gravitational lensing, etc.). The general idea of going beyond this simple paradigm is what characterises most of the efforts made in recent years: the study of second and higher-order cosmological perturbations including all general relativistic contributions -- also in connection with primordial non-Gaussianities -- the idea of defining large-scale structure observables directly from a general relativistic perspective, the various attempts to go beyond the Newtonian approximation in the study of non-linear gravitational dynamics, by using e.g., Post-Newtonian treatments, are all examples of this general trend. Here we summarise some of these ...
Relativistic Thermodynamics: A Modern 4-Vector Approach
J. Güémez
2011-01-01
Full Text Available Using the Minkowski relativistic 4-vector formalism, based on Einstein's equation, and the relativistic thermodynamics asynchronous formulation (Grøn (1973, the isothermal compression of an ideal gas is analyzed, considering an electromagnetic origin for forces applied to it. This treatment is similar to the description previously developed by Van Kampen (van Kampen (1969 and Hamity (Hamity (1969. In this relativistic framework Mechanics and Thermodynamics merge in the first law of relativistic thermodynamics expressed, using 4-vector notation, such as ΔUμ = Wμ + Qμ, in Lorentz covariant formulation, which, with the covariant formalism for electromagnetic forces, constitutes a complete Lorentz covariant formulation for classical physics.
Relativistic effect of spin and pseudospin symmetries
Chen, Shou-Wan
2012-01-01
Dirac Hamiltonian is scaled in the atomic units $\\hbar =m=1$, which allows us to take the non-relativistic limit by setting the Compton wavelength $% \\lambda \\rightarrow 0 $. The evolutions of the spin and pseudospin symmetries towards the non-relativistic limit are investigated by solving the Dirac equation with the parameter $\\lambda$. With $\\lambda$ transformation from the original Compton wavelength to 0, the spin splittings decrease monotonously in all spin doublets, and the pseudospin splittings increase in several pseudospin doublets, no change, or even reduce in several other pseudospin doublets. The various energy splitting behaviors of both the spin and pseudospin doublets with $\\lambda$ are well explained by the perturbation calculations of Dirac Hamiltonian in the present units. It indicates that the origin of spin symmetry is entirely due to the relativistic effect, while the origin of pseudospin symmetry cannot be uniquely attributed to the relativistic effect.
Relativistic calculations of coalescing binary neutron stars
Joshua Faber; Phillippe Grandclément; Frederic Rasio
2004-10-01
We have designed and tested a new relativistic Lagrangian hydrodynamics code, which treats gravity in the conformally flat approximation to general relativity. We have tested the resulting code extensively, finding that it performs well for calculations of equilibrium single-star models, collapsing relativistic dust clouds, and quasi-circular orbits of equilibrium solutions. By adding a radiation reaction treatment, we compute the full evolution of a coalescing binary neutron star system. We find that the amount of mass ejected from the system, much less than a per cent, is greatly reduced by the inclusion of relativistic gravitation. The gravity wave energy spectrum shows a clear divergence away from the Newtonian point-mass form, consistent with the form derived from relativistic quasi-equilibrium fluid sequences.
Non-Newtonian Properties of Relativistic Fluids
Koide, Tomoi
2010-01-01
We show that relativistic fluids behave as non-Newtonian fluids. First, we discuss the problem of acausal propagation in the diffusion equation and introduce the modified Maxwell-Cattaneo-Vernotte (MCV) equation. By using the modified MCV equation, we obtain the causal dissipative relativistic (CDR) fluid dynamics, where unphysical propagation with infinite velocity does not exist. We further show that the problems of the violation of causality and instability are intimately related, and the relativistic Navier-Stokes equation is inadequate as the theory of relativistic fluids. Finally, the new microscopic formula to calculate the transport coefficients of the CDR fluid dynamics is discussed. The result of the microscopic formula is consistent with that of the Boltzmann equation, i.e., Grad's moment method.
Relativistic Effects at the Freshman Level.
Banna, M. Salim
1985-01-01
Summarizes the content of a lecture in which relativistic effects in chemistry are introduced through a calculation that illustrates these effects on the s and p electrons and that can be verified by photoelectron spectroscopy data. (JN)
Star Products for Relativistic Quantum Mechanics
Henselder, P.
2007-01-01
The star product formalism has proved to be an alternative formulation for nonrelativistic quantum mechanics. We want introduce here a covariant star product in order to extend the star product formalism to relativistic quantum mechanics in the proper time formulation.
Relabeling symmetry in relativistic fluids and plasmas
Kawazura, Yohei; Fukumoto, Yasuhide
2014-01-01
The conservation of the recently formulated relativistic canonical helicity [Yoshida Z, Kawazura Y, and Yokoyama T 2014 J. Math. Phys. 55 043101] is derived from Noether's theorem by constructing an action principle on the relativistic Lagrangian coordinates (we obtain general cross helicities that include the helicity of the canonical vorticity). The conservation law is, then, explained by the relabeling symmetry pertinent to the Lagrangian label of fluid elements. Upon Eulerianizing the Noether current, the purely spatial volume integral on the Lagrangian coordinates is mapped to a space-time mixed three-dimensional integral on the four-dimensional Eulerian coordinates. The relativistic conservation law in the Eulerian coordinates is no longer represented by any divergence-free current; hence, it is not adequate to regard the relativistic helicity (represented by the Eulerian variables) as a Noether charge, and this stands the reason why the "conventional helicity" is no longer a constant of motion. We have...
Relativistic diffusion equation from stochastic quantization
Kazinski, P O
2007-01-01
The new scheme of stochastic quantization is proposed. This quantization procedure is equivalent to the deformation of an algebra of observables in the manner of deformation quantization with an imaginary deformation parameter (the Planck constant). We apply this method to the models of nonrelativistic and relativistic particles interacting with an electromagnetic field. In the first case we establish the equivalence of such a quantization to the Fokker-Planck equation with a special force. The application of the proposed quantization procedure to the model of a relativistic particle results in a relativistic generalization of the Fokker-Planck equation in the coordinate space, which in the absence of the electromagnetic field reduces to the relativistic diffusion (heat) equation. The stationary probability distribution functions for a stochastically quantized particle diffusing under a barrier and a particle in the potential of a harmonic oscillator are derived.
Relativistic Langevin equation for runaway electrons
Mier, J. A.; Martin-Solis, J. R.; Sanchez, R.
2016-10-01
The Langevin approach to the kinetics of a collisional plasma is developed for relativistic electrons such as runaway electrons in tokamak plasmas. In this work, we consider Coulomb collisions between very fast, relativistic electrons and a relatively cool, thermal background plasma. The model is developed using the stochastic equivalence of the Fokker-Planck and Langevin equations. The resulting Langevin model equation for relativistic electrons is an stochastic differential equation, amenable to numerical simulations by means of Monte-Carlo type codes. Results of the simulations will be presented and compared with the non-relativistic Langevin equation for RE electrons used in the past. Supported by MINECO (Spain), Projects ENE2012-31753, ENE2015-66444-R.
Solutions of relativistic radial quasipotential equations
Minh, V.X.; Kadyshevskii, V.G.; Zhidkov, E.P.
1985-11-01
A systematic approach to the investigation of relativistic radial quasipotential equations is developed. The quasipotential equations can be interpreted either as linear equations in finite differences of fourth and second orders, respectively, or as differential equations of infinite order.
Spin, localization and uncertainty of relativistic fermions
Céleri, Lucas C; Terno, Daniel R
2016-01-01
We describe relations between several relativistic spin observables and derive a Lorentz-invariant characteristic of a reduced spin density matrix. A relativistic position operator that satisfies all the properties of its non-relativistic analogue does not exist. Instead we propose two causality-preserving positive operator-valued measures (POVM) that are based on projections onto one-particle and antiparticle spaces, and on the normalized energy density. They predict identical expectation values for position. The variances differ by less than a quarter of the squared de Broglie wavelength and coincide in the non-relativistic limit. Since the resulting statistical moment operators are not canonical conjugates of momentum, the Heisenberg uncertainty relations need not hold. Indeed, the energy density POVM leads to a lower uncertainty. We reformulate the standard equations of the spin dynamics by explicitly considering the charge-independent acceleration, allowing a consistent treatment of backreaction and incl...
Relativistic Model for two-band Superconductivity
Ohsaku, Tadafumi
2003-01-01
To understand the superconductivity in MgB2, several two-band models of superconductivity were proposed. In this paper, by using the relativistic fermion model, we clearize the effect of the lower band in the superconductivity.
Test of Relativistic Gravity for Propulsion at the Large Hadron Collider
Felber, Franklin
2010-01-01
A design is presented of a laboratory experiment that could test the suitability of relativistic gravity for propulsion of spacecraft to relativistic speeds. An exact time-dependent solution of Einstein's gravitational field equation confirms that even the weak field of a mass moving at relativistic speeds could serve as a driver to accelerate a much lighter payload from rest to a good fraction of the speed of light. The time-dependent field of ultrarelativistic particles in a collider ring is calculated. An experiment is proposed as the first test of the predictions of general relativity in the ultrarelativistic limit by measuring the repulsive gravitational field of bunches of protons in the Large Hadron Collider (LHC). The estimated `antigravity beam' signal strength at a resonant detector of each proton bunch is 3 nm/s2 for 2 ns during each revolution of the LHC. This experiment can be performed off-line, without interfering with the normal operations of the LHC.
牛哲辉; 赵尊练; 巩振辉; 杜磊
2009-01-01
To study the effects of iron on line pepper resistance to virus, the line pepper cultivar Shan-jiao 2006 was employed in this research, and cultured with different iron nutrition levels (i. e. iron 1, iron 2, iron 3, and iron 4). After seedling infected with TMV by means of artificial inoculation, the activity of POD, CAT and the content of MDA in line peppers was determined every other day, and on the 20th day the dry and fresh weight of seedling over and under ground were determined. The result showed: under all Fe~(2+) nutrition levels, compared with the control group, the activity of POD, CAT and the content of MDA in infected TMV treatment were increased. In all treatment, the seeding treated with the level 3 of iron, the activity of POD and CAT of iron 3 treatment was the highest, and the content of MDA was the lowest. In all treatments, the dry weight, fresh weight of overground part and under-ground part in iron 3 treatment were the highest whether control or infected TMV group.%为了探讨铁元素对线辣椒抗(耐)病毒病的影响,本研究选用线辣椒品种"陕椒2006",利用不同的Fe~(2-)离子浓度进行水培并人工接种TMV(烟草花叶病毒),然后每隔1 d测定POD(过氧化物酶)、CAT(过氧化氢酶)活性和MDA(丙二醛)含量,第20天测定地上、地下部干质量和鲜质量.结果表明:陕椒2006在不同Fe2+浓度水培条件下,和对照相比,接种TMV的POD、CAT活性及MDA含量均有所升高.其中,铁3处理的幼苗在接种TMV后POD、CAT活性升高最明显,MDA含量最低.同时,铁3处理无论是对照还是接种TMV处理,其地上、地下部干质量、鲜质量均最高.
李固成
2013-01-01
针对钢铁企业高炉布料溜槽衬板所处的恶劣作业环境,研究开发出具有一定耐高温、耐腐蚀性的Cr26MoWVTiRE高铬合金铸铁材料.在经1 020,～1 050℃淬火+320～520℃回火,材料的硬度达到HRC 60～62,冲击韧度ak＞5 J/cm2.Mo、W合金和V、Ti等强碳化物元素的复合加入,提高了溜槽衬板的硬韧性、红硬性和高耐磨性,衬板实际使用寿命超过18个月.与镶铸硬质合金溜槽衬板相比,该衬板具有生产工艺简单、成本低、性价比高等特点,有一定推广应用价值.%Aiming at the bad working environment of distributing chute for iron and steel enterprises furnace,Cr26MoWVTiRE high chromium alloy cast iron material was developed,which has high temperature resistance,corrosion resistance.After 1 020-1 050 ℃ quenching and 320-520 ℃ tempering,the material hardness reached HRC 60-62,and impact toughness ak 5 J/cm2.The hardness and toughness,red hardness,high-wearing feature were improved by composite addition ofMo,W alloy and V,Ti and other strong carbide elements,and the service life of lining plate was more than 18 months.Compared to the cast-in hard alloy chute lining plate,it has the advantages such as simple production process,low cost,high performance/cast ratio,and deserves popularization.
On Lorentz invariants in relativistic magnetic reconnection
Yang, Shu-Di; Wang, Xiao-Gang
2016-08-01
Lorentz invariants whose nonrelativistic correspondences play important roles in magnetic reconnection are discussed in this paper. Particularly, the relativistic invariant of the magnetic reconnection rate is defined and investigated in a covariant two-fluid model. Certain Lorentz covariant representations for energy conversion and magnetic structures in reconnection processes are also investigated. Furthermore, relativistic measures for topological features of reconnection sites, particularly magnetic nulls and separatrices, are analyzed.
On the convexity of Relativistic Hydrodynamics
Ibáñez, José María; Martí, José María; Miralles, Juan Antonio; 10.1088/0264-9381/30/5/057002
2013-01-01
The relativistic hydrodynamic system of equations for a perfect fluid obeying a causal equation of state is hyperbolic (Anile 1989 {\\it Relativistic Fluids and Magneto-Fluids} (Cambridge: Cambridge University Press)). In this report, we derive the conditions for this system to be convex in terms of the fundamental derivative of the equation of state (Menikoff and Plohr 1989 {\\it Rev. Mod. Phys.} {\\bf 61} 75). The classical limit is recovered.
Benedicks effect in a relativistic simple fluid
Garcia-Perciante, A L; Garcia-Colin, L S
2013-01-01
According to standard thermophysical theories, cross effects are mostly present in multicomponent systems. In this paper we show that for relativistic fluids an electric field generates a heat flux even in the single component case. In the non-relativistic limit the effect vanishes and Fourier's law is recovered. This result is novel and may have applications in the transport properties of very hot plasmas.
New Developments in Relativistic Viscous Hydrodynamics
Romatschke, Paul
2009-01-01
Starting with a brief introduction into the basics of relativistic fluid dynamics, I discuss our current knowledge of a relativistic theory of fluid dynamics in the presence of (mostly shear) viscosity. Derivations based on the generalized second law of thermodynamics, kinetic theory, and a complete second-order gradient expansion are reviewed. The resulting fluid dynamic equations are shown to be consistent for all these derivations, when properly accounting for the respective region of appl...
Limits and Signatures of Relativistic Spaceflight
Yurtsever, Ulvi
2015-01-01
While special relativity imposes an absolute speed limit at the speed of light, our Universe is not empty Minkowski spacetime. The constituents that fill the interstellar/intergalactic vacuum, including the cosmic microwave background photons, impose a lower speed limit on any object travelling at relativistic velocities. Scattering of cosmic microwave phtotons from an ultra-relativistic object may create radiation with a characteristic signature allowing the detection of such objects at large distances.
Chiral quark model with relativistic kinematics
Garcilazo, H
2003-01-01
The non-strange baryon spectrum is studied within a three-body model that incorporates relativistic kinematics. We found that the combined effect of relativistic kinematics together with the pion exchange between quarks is able to reverse the order of the first positive- and negative-parity nucleon excited states as observed experimentally. Including the chiral partner of the pion (the $\\sigma$ meson) leads to an overall good description of the spectrum.
Relativistic diffusive motion in random electromagnetic fields
Haba, Z, E-mail: zhab@ift.uni.wroc.pl [Institute of Theoretical Physics, University of Wroclaw, 50-204 Wroclaw, Plac Maxa Borna 9 (Poland)
2011-08-19
We show that the relativistic dynamics in a Gaussian random electromagnetic field can be approximated by the relativistic diffusion of Schay and Dudley. Lorentz invariant dynamics in the proper time leads to the diffusion in the proper time. The dynamics in the laboratory time gives the diffusive transport equation corresponding to the Juettner equilibrium at the inverse temperature {beta}{sup -1} = mc{sup 2}. The diffusion constant is expressed by the field strength correlation function (Kubo's formula).
R. Nanthini; K. R. Mamatha; Geetha Shivamurthy; Kavitha, R.
2015-01-01
Background: Prevalence of iron deficiency anemia (IDA) is 58% among pregnant women in India. Oral iron therapy is recommended as first-line therapy in mild anemia. Moderate anemia in pregnancy results in high maternal morbidity and mortality. In India, women become pregnant with low iron stores, where oral iron therapy cannot meet the requirement and need parenteral iron therapy. This study was undertaken to evaluate the efficacy and safety of iron sucrose complex (ISC) in pregnant women with...
Convexity and symmetrization in relativistic theories
Ruggeri, T.
1990-09-01
There is a strong motivation for the desire to have symmetric hyperbolic field equations in thermodynamics, because they guarantee well-posedness of Cauchy problems. A generic quasi-linear first order system of balance laws — in the non-relativistic case — can be shown to be symmetric hyperbolic, if the entropy density is concave with respect to the variables. In relativistic thermodynamics this is not so. This paper shows that there exists a scalar quantity in relativistic thermodynamics whose concavity guarantees a symmetric hyperbolic system. But that quantity — we call it —bar h — is not the entropy, although it is closely related to it. It is formed by contracting the entropy flux vector — ha with a privileged time-like congruencebar ξ _α . It is also shown that the convexity of h plus the requirement that all speeds be smaller than the speed of light c provide symmetric hyperbolic field equations for all choices of the direction of time. At this level of generality the physical meaning of —h is unknown. However, in many circumstances it is equal to the entropy. This is so, of course, in the non-relativistic limit but also in the non-dissipative relativistic fluid and even in relativistic extended thermodynamics for a non-degenerate gas.
The relativistic geoid: redshift and acceleration potential
Philipp, Dennis; Lämmerzahl, Claus; Puetzfeld, Dirk; Hackmann, Eva; Perlick, Volker
2017-04-01
We construct a relativistic geoid based on a time-independent redshift potential, which foliates the spacetime into isochronometric surfaces. This relativistic potential coincides with the acceleration potential for isometric congruences. We show that the a- and u- geoid, defined in a post-Newtonian framework, coincide also in a more general setup. Known Newtonian and post-Newtonian results are recovered in the respective limits. Our approach offers a relativistic definition of the Earth's geoid as well as a description of the Earth itself (or observers on its surface) in terms of an isometric congruence. Being fully relativistic, this notion of a geoid can also be applied to other compact objects such as neutron stars. By definition, this relativistic geoid can be determined by a congruence of Killing observers equipped with standard clocks by comparing their frequencies as well as by measuring accelerations of objects that follow the congruence. The redshift potential gives the correct result also for frequency comparison through optical fiber links as long as the fiber is at rest w.r.t. the congruence. We give explicit expressions for the relativistic geoid in the Kerr spacetime and the Weyl class of spacetimes. To investigate the influence of higher order mass multipole moments we compare the results for the Schwarzschild case to those obtained for the Erez-Rosen and q-metric spacetimes.
Relativistic Measurements from Timing the Binary Pulsar PSR B1913+16
Weisberg, Joel M
2016-01-01
We present relativistic analyses of 9257 measurements of times-of-arrival from the first binary pulsar, PSR B1913+16, acquired over the last thirty-five years. The determination of the 'Keplerian' orbital elements plus two relativistic terms completely characterizes the binary system, aside from an unknown rotation about the line of sight; leading to a determination of the masses of the pulsar and its companion: 1.438 $\\pm$ 0.001 solar masses and 1.390 $\\pm$ 0.001 solar masses, respectively. In addition, the complete system characterization allows the creation of tests of relativistic gravitation by comparing measured and predicted sizes of various relativistic phenomena. We find that the ratio of observed orbital period decrease due to gravitational wave damping (corrected by a kinematic term) to the general relativistic prediction, is 0.9983 pm 0.0016; thereby confirming the existence and strength of gravitational radiation as predicted by general relativity. For the first time in this system, we have also ...
Relativistic baryonic jets from an ultraluminous supersoft X-ray source
Liu, Ji-Feng; Wang, Song; Justham, Stephen; Lu, You-Jun; Gu, Wei-Min; Liu, Qing-Zhong; Di Stefano, Rosanne; Guo, Jin-Cheng; Cabrera-Lavers, Antonio; Alvarez, Pedro; Cao, Yi; Kulkarni, Shri
2015-01-01
The formation of relativistic jets by an accreting compact object is one of the fundamental mysteries of astrophysics. While the theory is poorly understood, observations of relativistic jets from systems known as microquasars\\cite{Mirabel98,Paredes03} have led to a well-established phenomenology\\cite{Fender04,Migliari06}. Relativistic jets are not expected from sources with soft or supersoft X-ray spectra, although two such systems are known to produce relatively low-velocity bipolar outflows\\cite{Southwell96,Becker98}. Here we report optical spectra of an ultraluminous supersoft X-ray source (ULS\\cite{DiStefano03,Swartz02}) in the nearby galaxy M81 (M81 ULS-1\\cite{Liu08a,Liu08b}) showing blueshifted broad H\\alpha\\ emission lines, characteristic of baryonic jets with relativistic speeds. The time variable jets have projected velocities ~17 per cent of the speed of light, and seem similar to those in the prototype microquasar SS 433\\cite{Margon84,Blundell07}. Such relativistic jets are not expected to be laun...
Discovery of Relativistic Outflow in the Seyfert Galaxy Ark 564
Gupta, A; Krongold, Y; Nicastro, F
2013-01-01
We present Chandra high energy transmission grating spectra of the narrow-line Seyfert-1 galaxy Ark 564. The spectrum shows numerous absorption lines which are well modeled with low velocity outflow components usually observed in Seyfert galaxies (Gupta et al. 2013). There are, however, some residual absorption lines which are not accounted for by low-velocity outflows. Here we present identifications of the strongest lines as K{\\alpha} transitions of OVII(two lines) and OVI at outflow velocities of ~0.1c. These lines are detected at 6.9{\\sigma}, 6.2{\\sigma}, and 4.7{\\sigma} respectively and cannot be due to chance statistical fluctuations. Photoionization models with ultra-high velocity components improves the spectral fit significantly, providing further support for the presence of relativistic outflow in this source. Without knowing the location of the absorber, its mass and energy outflow rates cannot be well constrained; we find E$\\dot{E}(outflow)/L_{bo}$ ranging from < 0.001% to 60% using different a...
Relativistic Precessing Jets and Cosmological $\\gamma$ Ray Bursts
Blackman, E G; Field, G B; Blackman, Eric G.; Yi, Insu; Field, George B.
1996-01-01
We discuss the possibility that gamma-ray bursts may result from cosmological relativistic blob emitting neutron star jets that precess past the line of sight. Beaming reduces the energy requirements, so that the jet emission can last longer than the observed burst duration. One precession mode maintains a short duration time scale, while a second keeps the beam from returning to the line of sight, consistent with the paucity of repeaters. The long life of these objects reduces the number required for production as compared to short lived jets. Blobs can account for the time structure of the bursts. Here we focus largely on kinematic and time scale considerations of beaming, precession, and blobs--issues which are reasonably independent of the acceleration and jet collimation mechanisms. We do suggest that large amplitude electro-magnetic waves could be a source of blob acceleration.
Spontaneous radiation from relativistic electrons in a tapered undulator
Bosco, P.; Colson, W. B.
1983-01-01
The spectrum, angular distribution, polarization, and coherence properties of the radiation emitted by relativistic electrons undulating through a quasiperiodic tapered magnetic field are studied. Tapering the wavelength and/or field strength along the undulator's axis has the effect of spreading the spectral line to higher frequencies; interference over this broader spectral range results in a more complex line shape. The angular dependence, on the other hand, is not affected by the amount of taper. The polarization of the radiation in the forward direction is determined by the transverse polarization of the undulator, but the polarization changes off axis. The radiation patterns predicted here are distinct from those of untapered undulators and their detection is now feasible. They will provide useful diagnostics of electron trajectories and threshold behavior in free-electron-laser oscillators using tapered undulators.
Saito, Hiroshi
2014-01-01
ABSTRACT Remarkable progress was recently achieved in the studies on molecular regulators of iron metabolism. Among the main regulators, storage iron, iron absorption, erythropoiesis and hepcidin interact in keeping iron homeostasis. Diseases with gene-mutations resulting in iron overload, iron deficiency, and local iron deposition have been introduced in relation to the regulators of storage iron metabolism. On the other hand, the research on storage iron metabolism has not advanced since th...
The Relativistic Heavy Ion Collider control system
Clifford, T.S.; Barton, D.S.; Oerter, B.R.
1997-12-01
The Relativistic Heavy Ion Collider control system has been used in the commissioning of the AGS to RHIC transfer line and in the first RHIC sextant test. Much of the controls infrastructure for networks and links has been installed throughout the collider. All of the controls hardware modules needed to be built for early RHIC operations have been designed and tested. Many of these VME modules are already being used in normal AGS operations. Over 150 VME based front end computers and device controllers will be installed by the Summer of 1998 in order to be ready for Fall of 1998. A few features are being added to the front end computer core software. The bulk of the Accelerator Device Objects (ADOs) which are instantiated in the FECs, have been written and tested in the early commissioning. A configuration database has been designed. Generic control and display of ADO parameters via a spreadsheet like program on the console level computers was provided early on in the control system development. User interface tools that were developed for the AGS control system have been used in RHIC applications. Some of the basic operations programs, like alarm display and save/restore, that are used in the AGS operations have been or will be expanded to support RHIC operations. A model for application programs which involves a console level manager servicing ADOs have been verified with a few RHIC applications. More applications need to be written for the Fall of 1998 commissioning effort. A sequencer for automatic control of the fill is being written with the expectation that it will be useful in early commissioning.
... allergic to iron dextran injection; any other iron injections such as ferric carboxymaltose (Injectafer), ferumoxytol (Feraheme), iron sucrose (Venofer), or sodium ferric gluconate (Ferrlecit);any other ...
Investigation of relativistic runaway electrons
Jaspers, R.; Lopes Cardozo, N.J.; Schueller, F.C. [FOM-Instituut voor Plasmafysica, Rijnhuizen (Netherlands); Finken, K.H.; Mank, G.; Hoenen, F. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Plasmaphysik; Boedo, J. [California Univ., Los Angeles, CA (United States). Inst. of Plasma and Fusion Research
1993-12-31
The runaway generation during disruptions is regarded as a serious problem in future tokamak devices. The number and the high energy of these runaways can lead to considerable damage of wall components. In the TEXTOR tokamak (R{sub 0}=1.75 m, a=0.46 m; I{sub p}=350 kA, B{sub t}=2.25T, flat top time {approx_equal}2 s), low density discharges (n{sub e} < 1x10{sup 19} m{sup -3}) are analyzed to study the creation mechanism and the energy increase of the runaways. This is mainly done by the synchrotron radiation emitted by highly relativistic runaways (> 20 MeV). The general features of this synchrotron radiation will be described in Sect.2. In Sect.3 the creation rate of runaways is derived from this radiation. An intriguing observation made at the end of low density ohmic discharges is a fast increase in the pitch angle (i.e. the ratio of perpendicular to parallel velocity) from the runaways on a time scale of less than 65 {mu}s. This phenomenon is discussed in Sect.4. Finally some conclusions will be drawn on the implications these results have for future tokamak operation. (author) 4 refs., 3 figs.
Causal Categories: Relativistically Interacting Processes
Coecke, Bob; Lal, Raymond
2013-04-01
A symmetric monoidal category naturally arises as the mathematical structure that organizes physical systems, processes, and composition thereof, both sequentially and in parallel. This structure admits a purely graphical calculus. This paper is concerned with the encoding of a fixed causal structure within a symmetric monoidal category: causal dependencies will correspond to topological connectedness in the graphical language. We show that correlations, either classical or quantum, force terminality of the tensor unit. We also show that well-definedness of the concept of a global state forces the monoidal product to be only partially defined, which in turn results in a relativistic covariance theorem. Except for these assumptions, at no stage do we assume anything more than purely compositional symmetric-monoidal categorical structure. We cast these two structural results in terms of a mathematical entity, which we call a causal category. We provide methods of constructing causal categories, and we study the consequences of these methods for the general framework of categorical quantum mechanics.
Observation of relativistic antihydrogen atoms
Blanford, Glenn DelFosse
1998-01-01
An observation of relativistic antihydrogen atoms is reported in this dissertation. Experiment 862 at Fermi National Accelerator Laboratory observed antihydrogen atoms produced by the interaction of a circulating beam of high momentum (3 < p < 9 GeV/c) antiprotons and a jet of molecular hydrogen gas. Since the neutral antihydrogen does not bend in the antiproton source magnets, the detectors could be located far from the interaction point on a beamline tangent to the storage ring. The detection of the antihydrogen is accomplished by ionizing the atoms far from the interaction point. The positron is deflected by a magnetic spectrometer and detected, as are the back to back photons resulting from its annihilation. The antiproton travels a distance long enough for its momentum and time of flight to be measured accurately. A statistically significant sample of 101 antihydrogen atoms has been observed. A measurement of the cross section for {bar H}{sup 0} production is outlined within. The cross section corresponds to the process where a high momentum antiproton causes e{sup +} e{sup -} pair creation near a nucleus with the e{sup +} being captured by the antiproton. Antihydrogen is the first atom made exclusively of antimatter to be detected. The observation experiment's results are the first step towards an antihydrogen spectroscopy experiment which would measure the n = 2 Lamb shift and fine structure.
The Relativistic Heavy Ion Collider
Fischer, Wolfram
The Relativistic Heavy Ion Collider (RHIC), shown in Fig. 1, was build to study the interactions of quarks and gluons at high energies [Harrison, Ludlam and Ozaki (2003)]. The theory of Quantum Chromodynamics (QCD) describes these interactions. One of the main goals for the RHIC experiments was the creation and study of the Quark-Gluon Plasma (QGP), which was expected to be formed after the collision of heavy ions at a temperature of approximately 2 trillion kelvin (or equivalently an energy of 150 MeV). The QGP is the substance which existed only a few microseconds after the Big Bang. The QGP was anticipated to be weakly interacting like a gas but turned out to be strongly interacting and more like a liquid. Among its unusual properties is its extremely low viscosity [Auerbach and Schlomo (2009)], which makes the QGP the substance closest to a perfect liquid known to date. The QGP is opaque to moderate energy quarks and gluons leading to a phenomenon called jet quenching, where of a jet and its recoil jet only one is observable and the other suppressed after traversing and interacting with the QGP [Jacak and Müller (2012)]...
BIRKHOFF'S EQUATIONS AND GEOMETRICAL THEORY OF ROTATIONAL RELATIVISTIC SYSTEM
LUO SHAO-KAI; CHEN XIANG-WEI; FU JING-LI
2001-01-01
The Birkhoffian and Birkhoff's functions of a rotational relativistic system are constructed, the Pfaff action of rotational relativistic system is defined, the Pfaff-Birkhoff principle of a rotational relativistic system is given, and the Pfaff-Birkhoff-D'Alembert principles and Birkhoff's equations of rotational relativistic system are constructed. The geometrical description of a rotational relativistic system is studied, and the exact properties of Birkhoff's equations and their forms onR × T*M for a rotational relativistic system are obtained. The global analysis of Birkhoff's equations for a rotational relativistic system is studied, the global properties of autonomous, semi-autonomous and non-autonomous rotational relativistic Birkhoff's equations, and the geometrical properties of energy change for rotational relativistic Birkhoff's equations are given.
Jeong, Seulki [Seoul Center, Korea Basic Science Institute, 6-7, Inchon-ro 22-gil, Seongbuk-gu, Seoul 02855 (Korea, Republic of); Yang, Kyung [Division of Public Infrastructure Assessment, Environmental Assessment Group, Korea Environmental Institute, Sejong 30147 (Korea, Republic of); Jho, Eun Hea [Department of Environmental Science, Hankuk University of Foreign Studies, 81 Oedae-ro, Mohyeonmyeon, Cheoin-gu, Yongin-si, Gyeonggi-do 17035 (Korea, Republic of); Nam, Kyoungphile, E-mail: kpnam@snu.ac.kr [Department of Civil and Environmental Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826 (Korea, Republic of)
2017-05-15
Highlights: • Arsenic (As)-adsorbed and As-coprecipiated two-line ferrihydrites were synthesized. • Bioaccessibility was closely related to chemical binding type of As in Fe oxide. • Chemical binding type needs to be considered to characterize the risk of As in soil. - Abstract: Bioaccessible concentrations of As associated with Fe oxide as different chemical binding types were determined in soils using the in vitro Physiologically Based Extraction Test (PBET). When compared to the five-step sequential extraction data, most of the As extracted by in vitro PBET originated from the amorphous Fe oxide-bound fraction, and more importantly, the bioaccessibility of As ranged from 0 to 58.8% in 24 soil samples. Two batches of ferrihydrite were synthesized separately. For one batch, As was adsorbed onto the ferrihydrite after synthesis; for the other one, As was added while synthesizing ferrihydrite to co-precipitate. The bioaccessible concentration of As determined by in vitro PBET of the former was 415 mg of As/kg of ferrihydrite and that of the latter was 67 mg of As/kg of ferrihydrite. X-ray photoelectron spectra (XPS) analysis indicated that As–O–Fe bonds were evident in As-associated ferrihydrite sample and especially, As was found within the Fe oxide lattice in the co-precipitated sample. Our data suggest that binding type between As and Fe oxide should be considered when determining the bioaccessibility of As in soil, which, in turn, greatly influences the realistic risk of As present in soil.
2012-01-01
We have engineered the tropical root crop cassava (Manihot esculenta) to express the Chlamydomonas reinhardtii iron assimilatory gene, FEA1, in its storage roots with the objective of enhancing the root nutritional qualities. Iron levels in mature cassava storage roots were increased from 10 to 36 ppm in the highest iron accumulating transgenic lines. These iron levels are sufficient to meet the minimum daily requirement for iron in a 500 g meal. Significantly, the expression of the FEA1 gene...
Dennis, Brian R.; Dan, Chau; Jain, Rajmal; Schwartz, Richard A.; Tolbert, Anne K.
2008-01-01
The equivalent width of the iron-line complex at 6.7 keV seen in flare X-ray spectra suggests that the iron abundance of the hottest plasma at temperatures >approx.10 MK may sometimes be significantly lower than the nominal coronal abundance of four times the photospheric value that is commonly assumed. This conclusion is based on X-ray spectral observations of several flares seen in common with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Solar X-ray Spectrometer (SOXS) on the second Indian geostationary satellite, GSAT-2. The implications of this will be discussed as it relates to the origin of the hot flare plasma - either plasma already in the corona that is directly heated during the flare energy release process or chromospheric plasma that is heated by flare-accelerated particles and driven up into the corona. Other possible explanations of lower-than-expected equivalent widths of the iron-line complex will also be discussed.
Relativistic Hotspots in FR II Radio Sources
Chartrand, Alex M.; Miller, B. P.; Brandt, W. N.; Gawronski, M. P.; Cederbloom, S. E.
2011-01-01
We present a list of six FR II radio sources that are candidates to possess hotspots with modestly relativistic (v/c > 0.2) bulk velocities, in contrast to the vast majority of FR II radio sources that possess non-relativistic hotspot bulk velocities (e.g., v/c = 0.03+/- 0.02 from Scheuer 1995). These objects display arm- length and flux-ratio asymmetries between lobes that self-consistently indicate relativistic motion. The candidates are selected from the FIRST 1.4 GHz survey (including but not limited to the catalog of FR II quasars of de Vries et al. 2006) with the requirement that the radio core have a spectroscopic SDSS counterpart. We find no significant difference in the number of neighboring sources within 300 projected kpc of the candidate sources and randomly selected nearby regions. The deprojected and light travel-time corrected lobe distances are not abnormal for FR II sources, and neither are the core-to-lobe flux ratios after correcting for lobe beaming. We briefly consider four possibilities for these type of objects: (i) environmental interactions randomly mimicking relativistic effects, (ii) a restarted jet causing the near hotspot to brighten while the far hotspot still appears faint, (iii) observation during a short interval common to FR II lifetimes during which the hotspot decelerates from relativistic to non-relativistic velocities, and (iv) innately unusual characteristics (e.g., a mass-loaded jet) driving relativistic bulk velocities in the hotspots of a small fraction (< 1%) of FR II objects. We favor the last interpretation but cannot rule out the alternatives. We also comment on the useful external constraints such objects provide to the evaluation of hotspot X-ray emission mechanisms.
A systematic sequence of relativistic approximations.
Dyall, Kenneth G
2002-06-01
An approach to the development of a systematic sequence of relativistic approximations is reviewed. The approach depends on the atomically localized nature of relativistic effects, and is based on the normalized elimination of the small component in the matrix modified Dirac equation. Errors in the approximations are assessed relative to four-component Dirac-Hartree-Fock calculations or other reference points. Projection onto the positive energy states of the isolated atoms provides an approximation in which the energy-dependent parts of the matrices can be evaluated in separate atomic calculations and implemented in terms of two sets of contraction coefficients. The errors in this approximation are extremely small, of the order of 0.001 pm in bond lengths and tens of microhartrees in absolute energies. From this approximation it is possible to partition the atoms into relativistic and nonrelativistic groups and to treat the latter with the standard operators of nonrelativistic quantum mechanics. This partitioning is shared with the relativistic effective core potential approximation. For atoms in the second period, errors in the approximation are of the order of a few hundredths of a picometer in bond lengths and less than 1 kJ mol(-1) in dissociation energies; for atoms in the third period, errors are a few tenths of a picometer and a few kilojoule/mole, respectively. A third approximation for scalar relativistic effects replaces the relativistic two-electron integrals with the nonrelativistic integrals evaluated with the atomic Foldy-Wouthuysen coefficients as contraction coefficients. It is similar to the Douglas-Kroll-Hess approximation, and is accurate to about 0.1 pm and a few tenths of a kilojoule/mole. The integrals in all the approximations are no more complicated than the integrals in the full relativistic methods, and their derivatives are correspondingly easy to formulate and evaluate.
Linearization of Schwarzschild's line element - Application to the clock paradox.
Broucke, R.
1971-01-01
This article studies the relativistic theory of the motion of a particle in the presence of a uniform acceleration field. The problem is introduced as a linearization of the fundamental line element of general relativity. The linearized line element is a solution of Einstein's field equations. The equations of geodesics corresponding to this line element are solved and applied to the clock paradox problem.-
Post-Newtonian reference ellipsoid for relativistic geodesy
Kopeikin, Sergei; Han, Wenbiao; Mazurova, Elena
2016-02-01
We apply general relativity to construct the post-Newtonian background manifold that serves as a reference spacetime in relativistic geodesy for conducting a relativistic calculation of the geoid's undulation and the deflection of the plumb line from the vertical. We chose an axisymmetric ellipsoidal body made up of a perfect homogeneous fluid uniformly rotating around a fixed axis, as a source generating the reference geometry of the background manifold through Einstein's equations. We then reformulate and extend hydrodynamic calculations of rotating fluids done by a number of previous researchers for astrophysical applications to the realm of relativistic geodesy to set up algebraic equations defining the shape of the post-Newtonian reference ellipsoid. To complete this task, we explicitly perform all integrals characterizing gravitational field potentials inside the fluid body and represent them in terms of the elementary functions depending on the eccentricity of the ellipsoid. We fully explore the coordinate (gauge) freedom of the equations describing the post-Newtonian ellipsoid and demonstrate that the fractional deviation of the post-Newtonian level surface from the Maclaurin ellipsoid can be made much smaller than the previously anticipated estimate based on the astrophysical application of the coordinate gauge advocated by Bardeen and Chandrasekhar. We also derive the gauge-invariant relations of the post-Newtonian mass and the constant angular velocity of the rotating fluid with the parameters characterizing the shape of the post-Newtonian ellipsoid including its eccentricity, a semiminor axis, and a semimajor axis. We formulate the post-Newtonian theorems of Pizzetti and Clairaut that are used in geodesy to connect the geometric parameters of the reference ellipsoid to the physically measurable force of gravity at the pole and equator of the ellipsoid. Finally, we expand the post-Newtonian geodetic equations describing the post-Newtonian ellipsoid to
RAM: a Relativistic Adaptive Mesh Refinement Hydrodynamics Code
Zhang, Wei-Qun; /KIPAC, Menlo Park; MacFadyen, Andrew I.; /Princeton, Inst. Advanced Study
2005-06-06
The authors have developed a new computer code, RAM, to solve the conservative equations of special relativistic hydrodynamics (SRHD) using adaptive mesh refinement (AMR) on parallel computers. They have implemented a characteristic-wise, finite difference, weighted essentially non-oscillatory (WENO) scheme using the full characteristic decomposition of the SRHD equations to achieve fifth-order accuracy in space. For time integration they use the method of lines with a third-order total variation diminishing (TVD) Runge-Kutta scheme. They have also implemented fourth and fifth order Runge-Kutta time integration schemes for comparison. The implementation of AMR and parallelization is based on the FLASH code. RAM is modular and includes the capability to easily swap hydrodynamics solvers, reconstruction methods and physics modules. In addition to WENO they have implemented a finite volume module with the piecewise parabolic method (PPM) for reconstruction and the modified Marquina approximate Riemann solver to work with TVD Runge-Kutta time integration. They examine the difficulty of accurately simulating shear flows in numerical relativistic hydrodynamics codes. They show that under-resolved simulations of simple test problems with transverse velocity components produce incorrect results and demonstrate the ability of RAM to correctly solve these problems. RAM has been tested in one, two and three dimensions and in Cartesian, cylindrical and spherical coordinates. they have demonstrated fifth-order accuracy for WENO in one and two dimensions and performed detailed comparison with other schemes for which they show significantly lower convergence rates. Extensive testing is presented demonstrating the ability of RAM to address challenging open questions in relativistic astrophysics.
Iron sucrose injection is used treat iron-deficiency anemia (a lower than normal number of red blood cells due ... and may cause the kidneys to stop working). Iron sucrose injection is in a class of medications called iron ...
Full Text Available ... enough iron, your body starts using the iron it has stored. Soon, the stored iron gets used ... fewer red blood cells. The red blood cells it does make have less hemoglobin than normal. Iron- ...
RELATIVISTIC HEAVY ION COLLISIONS: EXPERIMENT
Friedlander, Erwin M.; Heckman, Harry H.
1982-04-01
Relativistic heavy ion physics began as a 'no man's land' between particle and nuclear physics, with both sides frowning upon it as 'unclean', because on one hand, hadronic interactions and particle production cloud nuclear structure effects, while on the other, the baryonic environment complicates the interpretation of production experiments. They have attempted to review here the experimental evidence on RHI collisions from the point of view that it represents a new endeavor in the understanding of strong interaction physics. Such an approach appears increasingly justified; first, by the accumulation of data and observations of new features of hadronic interactions that could not have been detected outside a baryonic environment; second, by the maturation of the field owing to the advances made over the past several years in experimental inquiries on particle production by RHI, including pions, kaons, hyperons, and searches for antiprotons; and third, by the steady and progressive increase in the energy and mass ranges of light nuclear beams that have become available to the experiment; indeed the energy range has widened from the {approx} 0.2 to 2 AGeV at the Bevalac to {approx}4 AGeV at Dubna and recently, to the quantum jump in energies to {approx} 1000 equivalent AGeV at the CERN PS-ISR. Accompanying these expansions in the energy frontier are the immediate prospects for very heavy ion beams at the Bevalac up to, and including, 1 AGeV {sup 238}U, thereby extending the 'mass frontier' to its ultimate extent.
Applying Relativistic Reconnection to Blazar Jets
Nalewajko, Krzysztof
2016-01-01
Rapid and luminous flares of non-thermal radiation observed in blazars require an efficient mechanism of energy dissipation and particle acceleration in relativistic active galactic nuclei (AGN) jets. Particle acceleration in relativistic magnetic reconnection is being actively studied by kinetic numerical simulations. Relativistic reconnection produces hard power-law electron energy distributions N(gamma) = N_0 gamma^(-p) exp(-gamma/gamma_max) with index p -> 1 and exponential cut-off Lorentz factor gamma_max ~ sigma in the limit of magnetization sigma = B^2/(4 pi w) >> 1 (where w is the relativistic enthalpy density). Reconnection in electron-proton plasma can additionally boost gamma_max by the mass ratio m_p/m_e. Hence, in order to accelerate particles to gamma_max ~ 10^6 in the case of BL Lacs, reconnection should proceed in plasma of very high magnetization sigma_max >~ 10^3. On the other hand, moderate mean jet magnetization values are required for magnetic bulk acceleration of relativistic jets, sigma...
Relativistic mixtures of charged and uncharged particles
Kremer, Gilberto M. [Departamento de Física, Universidade Federal do Paraná, Curitiba (Brazil)
2014-01-14
Mixtures of relativistic gases within the framework of Boltzmann equation are analyzed. Three systems are considered. The first one refers to a mixture of uncharged particles by using Grad’s moment method, where the relativistic mixture is characterized by the moments of the distribution functions: particle four-flows, energy-momentum tensors, and third-order moment tensors. In the second Fick’s law for a mixture of relativistic gases of non-disparate rest masses in a Schwarzschild metric are derived from an extension of Marle and McCormack model equations applied to a relativistic truncated Grad’s distribution function, where it is shown the dependence of the diffusion coefficient on the gravitational potential. The third one consists in the derivation of the relativistic laws of Ohm and Fourier for a binary mixtures of electrons with protons and electrons with photons subjected to external electromagnetic fields and in presence of gravitational fields by using the Anderson and Witting model of the Boltzmann equation.
General relativistic observables of the GRAIL mission
Turyshev, Slava G; Sazhin, Mikhail V
2012-01-01
We present a realization of astronomical relativistic reference frames in the solar system and its application to the GRAIL mission. We model the necessary spacetime coordinate transformations for light-trip time computations and address some practical aspects of the implementation of the resulting model. We develop all the relevant relativistic coordinate transformations that are needed to describe the motion of the GRAIL spacecraft and to compute all observable quantities. We take into account major relativistic effects contributing to the dual one-way range observable, which is derived from one-way signal travel times between the two GRAIL spacecraft. We develop a general relativistic model for this fundamental observable of GRAIL, accurate to 1 $\\mu$m. We develop and present a relativistic model for another key observable of this experiment, the dual one-way range-rate, accurate to 1 $\\mu$m/s. The presented formulation justifies the basic assumptions behind the design of the GRAIL mission. It may also be ...
Chaos and maps in relativistic rynamical systems
L. P. Horwitz
2000-01-01
Full Text Available The basic work of Zaslavskii et al showed that the classical non-relativistic electromagnetically kicked oscillator can be cast into the form of an iterative map on the phase space; the resulting evolution contains a stochastic flow to unbounded energy. Subsequent studies have formulated the problem in terms of a relativistic charged particle in interaction with the electromagnetic field. We review the structure of the covariant Lorentz force used to study this problem. We show that the Lorentz force equation can be derived as well from the manifestly covariant mechanics of Stueckelberg in the presence of a standard Maxwell field, establishing a connection between these equations and mass shell constraints. We argue that these relativistic generalizations of the problem are intrinsically inaccurate due to an inconsistency in the structure of the relativistic Lorentz force, and show that a reformulation of the relativistic problem, permitting variations (classically in both the particle mass and the effective “mass” of the interacting electromagnetic field, provides a consistent system of classical equations for describing such processes.
Schou, Morten; Bosselmann, Helle; Gaborit, Freja
2015-01-01
BACKGROUND: Both iron deficiency (ID) and cardiovascular biomarkers are associated with a poor outcome in heart failure (HF). The relationship between different cardiovascular biomarkers and ID is unknown, and the true prevalence of ID in an outpatient HF clinic is probably overlooked. OBJECTIVES.......043). CONCLUSION: ID is frequent in an outpatient HF clinic. ID is not associated with cardiovascular biomarkers after adjustment for traditional confounders. Inflammation, but not neurohormonal activation is associated with ID in systolic HF. Further studies are needed to understand iron metabolism in elderly HF...
Solved and unsolved problems in relativistic quantum chemistry
Kutzelnigg, Werner, E-mail: werner.kutzelnigg@rub.de [Lehrstuhl fuer Theoretische Chemie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)
2012-02-20
Graphical abstract: The graphical abstract represents the Dirac-Coulomb Hamiltonian in Fock space in a diagrammatic notation. A line (vertical or slanted) with an upgoing arrow represents an eletron, with a downgoing arrow a positron. A cross in the first line means the potential created by a nucleus, a broken line represents the Coulomb interaction between electrons and positrons. Highlights: Black-Right-Pointing-Pointer Relativistic many-electron theory needs a Fock space and a field-dependent vacuum. Black-Right-Pointing-Pointer A good starting point is QED in Coulomb gauge without transversal photons. Black-Right-Pointing-Pointer The Dirac underworld picture is obsolete. Black-Right-Pointing-Pointer A kinetically balanced even-tempered Gaussian basis is complete. Black-Right-Pointing-Pointer 'Quantum chemistry in Fock space is preferable over QED. - Abstract: A hierarchy of approximations in relativistic many-electron theory is discussed that starts with the Dirac equation and its expansion in a kinetically balanced basis, via a formulation of non-interacting electrons in Fock space (which is the only consistent way to deal with negative-energy states). The most straightforward approximate Hamiltonian for interacting electrons is derived from quantum electrodynamics (QED) in Coulomb gauge with the neglect of transversal photons. This allows an exact (non-perturbative) decoupling of the electromagnetic field from the fermionic field. The electric interaction of the fermions is non-retarded and non-quantized. The quantization of the fermionic field leads to a polarizable vacuum. The simplest (but somewhat problematic) approximation is a no-pair projected theory with external-field projectors. The Dirac-Coulomb operator in configuration space (first quantization) is not acceptable, even if the Brown-Ravenhall disease is much less virulent than often claimed. Effects of transversal photons, such as the Breit interaction and renormalized self-interaction can be
Relativistic Beaming and Orientation Effects in BL Lacertae Objects
F. C. Odo; A. A. Ubachukwu; A. E. Chukwude
2012-09-01
We use the correlation between the core-to-lobe radio luminosity ratio () and the linear size () of a sample of BL Lacertae objects to investigate the relativistic beaming and radio source orientation paradigm for high peaked and low-peaked BL Lacs (X-ray and radio selected BL Lacs respectively) and to constrain relativistic beaming model for this extreme class of active galactic nuclei. We show that the - distributions of the BL Lac populations contradict blazar orientation sequence, with the X-ray selected BL Lacs (XBLs) being more consistent with the beaming and orientation model. On the premise that Fanaroff-Riley Type I radio galaxies are the unbeamed parent population of these objects, we derive the bulk Lorentz factor of the jets, ∼ 7-20 corresponding to a critical cone angle for optimum boosting, c of ∼ 1° - 4°, while on average, these objects are inclined at 5° - 12° to the line-of-sight. The implications of these results for the blazar unification sequence are discussed.
Relativistic ion collisions as the source of hypernuclei
Botvina, A.S. [J.W. Goethe University, Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Russian Academy of Sciences, Institute for Nuclear Research, Moscow (Russian Federation); Bleicher, M.; Steinheimer, J. [J.W. Goethe University, Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Pochodzalla, J. [J. Gutenberg-Universitaet, Helmholtz-Institut Mainz, Mainz (Germany); J. Gutenberg-Universitaet Mainz, Institut fuer Kernphysik and PRISMA Cluster of Excellence, Mainz (Germany)
2016-08-15
We shortly review the theory of hypernuclei production in relativistic ion collisions, that is adequate to future experiments at BM rate at N, NICA, and FAIR. Within a hybrid approach we use transport, coalescence and statistical models to describe the whole process. We demonstrate that the origin of hypernuclei can be explained by typical baryon interactions, that is similar to the production of conventional nuclei. In particular, heavy hypernuclei are coming mostly from projectile and target residues, whereas light hypernuclei can be produced at all rapidities. The yields of hypernuclei increase considerably above the energy threshold for Λ hyperon production, and there is a tendency to saturation of yields of hypernuclei with increasing the beam energy up to few TeV. There are unique opportunities in relativistic ion collisions which are difficult to realize in traditional hypernuclear experiments: The produced hypernuclei have a broad distribution in masses and isospin. They can even reach beyond the neutron and proton drip-lines and that opens a chance to investigate properties of exotic hypernuclei. One finds also the abundant production of multi-strange nuclei, of bound and unbound hypernuclear states with new decay modes. In addition, we can directly get an information on the hypermatter both at high and low temperatures. (orig.)
Relativistic ion collisions as the source of hypernuclei
Botvina, A. S.; Bleicher, M.; Pochodzalla, J.; Steinheimer, J.
2016-08-01
We shortly review the theory of hypernuclei production in relativistic ion collisions, that is adequate to future experiments at BM@N, NICA, and FAIR. Within a hybrid approach we use transport, coalescence and statistical models to describe the whole process. We demonstrate that the origin of hypernuclei can be explained by typical baryon interactions, that is similar to the production of conventional nuclei. In particular, heavy hypernuclei are coming mostly from projectile and target residues, whereas light hypernuclei can be produced at all rapidities. The yields of hypernuclei increase considerably above the energy threshold for Λ hyperon production, and there is a tendency to saturation of yields of hypernuclei with increasing the beam energy up to few TeV. There are unique opportunities in relativistic ion collisions which are difficult to realize in traditional hypernuclear experiments: The produced hypernuclei have a broad distribution in masses and isospin. They can even reach beyond the neutron and proton drip-lines and that opens a chance to investigate properties of exotic hypernuclei. One finds also the abundant production of multi-strange nuclei, of bound and unbound hypernuclear states with new decay modes. In addition, we can directly get an information on the hypermatter both at high and low temperatures.
Particle acceleration in ultra-relativistic parallel shock waves
Meli, A
2003-01-01
Monte-Carlo computations for highly relativistic parallel shock particle acceleration are presented for upstream flow gamma factors, $\\Gamma=(1-V_{1}^{2}/c^{2})^{-0.5}$ with values between 5 and $10^{3}$. The results show that the spectral shape at the shock depends on whether or not the particle scattering is small angle with $\\delta \\theta 2r_{g} \\Gamma^{2}$ where $\\lambda$ is the scattering mean free path along the field line and $r_{g}$ the gyroradius, these quantities being measured in the plasma flow frame. The large angle scattering case exhibits distinctive structure superimposed on the basic power-law spectrum, largely absent in the pitch angle case. Also, both cases yield an acceleration rate faster than estimated by the conventional, non-relativistic expression, $t_{acc}=[c/(V_{1}-V_{2})] [\\lambda_{1}/V_{1}+\\lambda_{2}/V_{2}]$ where '1' and '2' refer to upstream and downstream and $\\lambda$ is the mean free path. A $\\Gamma^{2}$ energy enhancement factor in the first shock crossing cycle and a sign...
Particle Acceleration and Nonthermal Emission in Relativistic Astrophysical Shocks
Sironi, Lorenzo
The common observational feature of Pulsar Wind Nebulae (PWNe), gamma-ray bursts (GRBs), and AGN jets is a broad nonthermal spectrum of synchrotron and inverse Compton radiation. It is usually assumed that the emitting electrons are accelerated to a power-law distribution at relativistic shocks, via the so-called Fermi mechanism. Despite decades of research, the Fermi acceleration process is still not understood from first principles. An assessment of the micro-physics of particle acceleration in relativistic shocks is of paramount importance to unveil the properties of astrophysical nonthermal sources, and it is the subject of this dissertation. In the first part of this thesis, I explore by means of fully-kinetic first-principle particle-in-cell (PIC) simulations the properties of relativistic shocks that propagate in electron-positron and electron-proton plasmas carrying uniform magnetic fields. I find that nonthermal particle acceleration only occurs if the upstream magnetization is weak (sigma0.01) and quasi-perpendicular, yet they need to be efficient particle accelerators, in order to explain the prominent nonthermal signatures of these sources. Motivated by this discrepancy, I then relax the assumption of uniform pre-shock fields, and investigate the acceleration efficiency of perpendicular shocks that propagate in high-sigma flows with alternating magnetic fields. This is the geometry expected at the termination shock of pulsar winds, but it could also be relevant for Poynting-dominated jets in GRBs and AGNs. I show by means of PIC simulations that compression of the flow at the shock will force annihilation of nearby field lines, a process known as shock-driven reconnection. Magnetic reconnection can efficiently transfer the energy of alternating fields to the particles, generating flat power-law tails containing most of the particles. Finally, I directly relate the results of my PIC simulations to observations of nonthermal sources, by presenting a
Relativistic Consistent Angular-Momentum Projected Shell-Model:Relativistic Mean Field
LI Yan-Song; LONG Gui-Lu
2004-01-01
We develop a relativistic nuclear structure model, relativistic consistent angular-momentum projected shellmodel (RECAPS), which combines the relativistic mean-field theory with the angular-momentum projection method.In this new model, nuclear ground-state properties are first calculated consistently using relativistic mean-field (RMF)theory. Then angular momentum projection method is used to project out states with good angular momentum from a few important configurations. By diagonalizing the hamiltonian, the energy levels and wave functions are obtained.This model is a new attempt for the understanding of nuclear structure of normal nuclei and for the prediction of nuclear properties of nuclei far from stability. In this paper, we will describe the treatment of the relativistic mean field. A computer code, RECAPS-RMF, is developed. It solves the relativistic mean field with axial-symmetric deformation in the spherical harmonic oscillator basis. Comparisons between our calculations and existing relativistic mean-field calculations are made to test the model. These include the ground-state properties of spherical nuclei 16O and 208Pb,the deformed nucleus 20Ne. Good agreement is obtained.
Resistive Magnetohydrodynamic Simulations of Relativistic Magnetic Reconnection
Zenitani, Seiji; Hesse, Michael; Klimas, Alex
2010-01-01
Resistive relativistic magnetohydrodynamic (RRMHD) simulations are applied to investigate the system evolution of relativistic magnetic reconnection. A time-split Harten-Lan-van Leer method is employed. Under a localized resistivity, the system exhibits a fast reconnection jet with an Alfv enic Lorentz factor inside a narrow Petschek-type exhaust. Various shock structures are resolved in and around the plasmoid such as the post-plasmoid vertical shocks and the "diamond-chain" structure due to multiple shock reflections. Under a uniform resistivity, Sweet-Parker-type reconnection slowly evolves. Under a current-dependent resistivity, plasmoids are repeatedly formed in an elongated current sheet. It is concluded that the resistivity model is of critical importance for RRMHD modeling of relativistic magnetic reconnection.
On the convexity of Relativistic Ideal Magnetohydrodynamics
Ibáñez, José-María; Aloy, Miguel-Ángel; Martí, José-María; Miralles, Juan-Antonio
2015-01-01
We analyze the influence of the magnetic field in the convexity properties of the relativistic magnetohydrodynamics system of equations. To this purpose we use the approach of Lax, based on the analysis of the linearly degenerate/genuinely non-linear nature of the characteristic fields. Degenerate and non-degenerate states are discussed separately and the non-relativistic, unmagnetized limits are properly recovered. The characteristic fields corresponding to the material and Alfv\\'en waves are linearly degenerate and, then, not affected by the convexity issue. The analysis of the characteristic fields associated with the magnetosonic waves reveals, however, a dependence of the convexity condition on the magnetic field. The result is expressed in the form of a generalized fundamental derivative written as the sum of two terms. The first one is the generalized fundamental derivative in the case of purely hydrodynamical (relativistic) flow. The second one contains the effects of the magnetic field. The analysis ...
Relativistic dynamics, Green function and pseudodifferential operators
Cirilo-Lombardo, Diego Julio
2016-01-01
The central role played by pseudodifferential operators in relativistic dynamics is very well know. In this work, operators as the Schrodinger one (e.g: square root) are treated from the point of view of the non-local pseudodifferential Green functions. Starting from the explicit construction of the Green (semigroup) theoretical kernel, a theorem linking the integrability conditions and their dependence on the spacetime dimensions is given. Relativistic wave equations with arbitrary spin and the causality problem are discussed with the algebraic interpretation of the radical operator and their relation with coherent and squeezed states. Also we perform by mean of pure theoretical procedures (based in physical concepts and symmetry) the relativistic position operator which satisfies the conditions of integrability : it is non-local, Lorentz invariant and does not have the same problems as the "local"position operator proposed by Newton and Wigner. Physical examples, as Zitterbewegung and rogue waves, are prese...
General relativistic observables for the ACES experiment
Turyshev, Slava G; Toth, Viktor T
2015-01-01
We develop a high-precision model for relativistic observables of the Atomic Clock Ensemble in Space (ACES) experiment on the International Space Station (ISS). We develop all relativistic coordinate transformations that are needed to describe the motion of ACES in Earth orbit and to compute observable quantities. We analyze the accuracy of the required model as it applies to the proper-to-coordinate time transformations, light time equation, and spacecraft equations of motion. We consider various sources of nongravitational noise and their effects on ACES. We estimate the accuracy of orbit reconstruction that is needed to satisfy the ACES science objectives. Based on our analysis, we derive models for the relativistic observables of ACES, which also account for the contribution of atmospheric drag on the clock rate. We include the Earth's oblateness coefficient $J_2$ and the effects of major nongravitational forces on the orbit of the ISS. We demonstrate that the ACES reference frame is pseudo-inertial at th...
Relativistic mirrors in laser plasmas (analytical methods)
Bulanov, S. V.; Esirkepov, T. Zh; Kando, M.; Koga, J.
2016-10-01
Relativistic flying mirrors in plasmas are realized as thin dense electron (or electron-ion) layers accelerated by high-intensity electromagnetic waves to velocities close to the speed of light in vacuum. The reflection of an electromagnetic wave from the relativistic mirror results in its energy and frequency changing. In a counter-propagation configuration, the frequency of the reflected wave is multiplied by the factor proportional to the Lorentz factor squared. This scientific area promises the development of sources of ultrashort x-ray pulses in the attosecond range. The expected intensity will reach the level at which the effects predicted by nonlinear quantum electrodynamics start to play a key role. We present an overview of theoretical methods used to describe relativistic flying, accelerating, oscillating mirrors emerging in intense laser-plasma interactions.
Exact quantisation of the relativistic Hopfield model
Belgiorno, F., E-mail: francesco.belgiorno@polimi.it [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo 32, IT-20133 Milano (Italy); INdAM-GNFM (Italy); Cacciatori, S.L., E-mail: sergio.cacciatori@uninsubria.it [Department of Science and High Technology, Università dell’Insubria, Via Valleggio 11, IT-22100 Como (Italy); INFN sezione di Milano, via Celoria 16, IT-20133 Milano (Italy); Dalla Piazza, F., E-mail: f.dallapiazza@gmail.com [Università “La Sapienza”, Dipartimento di Matematica, Piazzale A. Moro 2, I-00185, Roma (Italy); Doronzo, M., E-mail: m.doronzo@uninsubria.it [Department of Science and High Technology, Università dell’Insubria, Via Valleggio 11, IT-22100 Como (Italy)
2016-11-15
We investigate the quantisation in the Heisenberg representation of a relativistically covariant version of the Hopfield model for dielectric media, which entails the interaction of the quantum electromagnetic field with the matter dipole fields, represented by a mesoscopic polarisation field. A full quantisation of the model is provided in a covariant gauge, with the aim of maintaining explicit relativistic covariance. Breaking of the Lorentz invariance due to the intrinsic presence in the model of a preferred reference frame is also taken into account. Relativistic covariance forces us to deal with the unphysical (scalar and longitudinal) components of the fields, furthermore it introduces, in a more tricky form, the well-known dipole ghost of standard QED in a covariant gauge. In order to correctly dispose of this contribution, we implement a generalised Lautrup trick. Furthermore, causality and the relation of the model with the Wightman axioms are also discussed.
Resistive Magnetohydrodynamic Simulations of Relativistic Magnetic Reconnection
Zenitani, Seiji; Klimas, Alex
2010-01-01
Resistive relativistic magnetohydrodynamic (RRMHD) simulations are applied to investigate the system evolution of relativistic magnetic reconnection. A time-split Harten--Lan--van Leer (HLL) method is employed. Under a localized resistivity, the system exhibits a fast reconnection jet with an Alfv\\'{e}nic Lorentz factor inside a narrow Petschek-type exhaust. Various shock structures are resolved in and around the plasmoid such as the post-plasmoid vertical shocks and the "diamond--chain" structure due to multiple shock reflections. Under a uniform resistivity, Sweet--Parker-type reconnection slowly evolves. Under a current-dependent resistivity, plasmoids are repeatedly formed in an elongated current sheet. It is concluded that the resistivity model is of critical importance for RRMHD modeling of relativistic magnetic reconnection.
INTRACLUSTER MEDIUM REHEATING BY RELATIVISTIC JETS
Perucho, Manel; Quilis, Vicent; Marti, Jose-Maria [Departament d' Astronomia i Astrofisica, Universitat de Valencia, c/Dr. Moliner 50, E-46100 Burjassot (Valencia) (Spain)
2011-12-10
Galactic jets are powerful energy sources reheating the intracluster medium in galaxy clusters. Their crucial role in the cosmic puzzle, motivated by observations, has been established by a great number of numerical simulations excluding the relativistic nature of these jets. We present the first relativistic simulations of the very long-term evolution of realistic galactic jets. Unexpectedly, our results show no buoyant bubbles, but large cocoon regions compatible with the observed X-ray cavities. The reheating is more efficient and faster than in previous scenarios, and it is produced by the shock wave driven by the jet, that survives for several hundreds of Myr. Therefore, the X-ray cavities in clusters produced by powerful relativistic jets would remain confined by weak shocks for extremely long periods and their detection could be an observational challenge.
The relativistic virial theorem and scale invariance
Gaite, Jose
2013-01-01
The virial theorem is related to the dilatation properties of bound states. This is realized, in particular, by the Landau-Lifshitz formulation of the relativistic virial theorem, in terms of the trace of the energy-momentum tensor. We construct a Hamiltonian formulation of dilatations in which the relativistic virial theorem naturally arises as the condition of stability against dilatations. A bound state becomes scale invariant in the ultrarelativistic limit, in which its energy vanishes. However, for very relativistic bound states, scale invariance is broken by quantum effects and the virial theorem must include the energy-momentum tensor trace anomaly. This quantum field theory virial theorem is directly related to the Callan-Symanzik equations. The virial theorem is applied to QED and then to QCD, focusing on the bag model of hadrons. In massless QCD, according to the virial theorem, 3/4 of a hadron mass corresponds to quarks and gluons and 1/4 to the trace anomaly.
Relativistic Scott correction for atoms and molecules
Solovej, Jan Philip; Sørensen, Thomas Østergaard; Spitzer, Wolfgang Ludwig
2010-01-01
We prove the first correction to the leading Thomas-Fermi energy for the ground state energy of atoms and molecules in a model where the kinetic energy of the electrons is treated relativistically. The leading Thomas-Fermi energy, established in [25], as well as the correction given here, are of ......We prove the first correction to the leading Thomas-Fermi energy for the ground state energy of atoms and molecules in a model where the kinetic energy of the electrons is treated relativistically. The leading Thomas-Fermi energy, established in [25], as well as the correction given here......, are of semiclassical nature. Our result on atoms and molecules is proved from a general semiclassical estimate for relativistic operators with potentials with Coulomb-like singularities. This semiclassical estimate is obtained using the coherent state calculus introduced in [36]. The paper contains a unified treatment...
Exact quantisation of the relativistic Hopfield model
Belgiorno, F; Piazza, F Dalla; Doronzo, M
2016-01-01
We investigate the quantisation in the Heisenberg representation of a relativistically covariant version of the Hopfield model for dielectric media, which entails the interaction of the quantum electromagnetic field with the matter dipole fields. The matter fields are represented by a mesoscopic polarization field. A full quantisation of the model is provided in a covariant gauge, with the aim of maintaining explicit relativistic covariance. Breaking of the Lorentz invariance due to the intrinsic presence in the model of a preferred reference frame is also taken into account. Relativistic covariance forces us to deal with the unphysical (scalar and longitudinal) components of the fields, furthermore it introduces, in a more tricky form, the well-known dipole ghost of standard QED in a covariant gauge. In order to correctly dispose of this contribution, we implement a generalized Lautrup trick. Furthermore, causality and the relation of the model with the Wightman axioms are also discussed.