A uniform model of the massive spinning particle in any dimension

The general model of an arbitrary spin massive particle in any dimensional space-time is derived on the basis of Kirillov - Kostant - Souriau approach. It is shown that the model allows consistent coupling to an arbitrary background of electromagnetic and gravitational fields.Comment: Latex, revised version of hep-th/981100

The Circum-Galactic Environment of Bright IRAS Galaxies

This paper studies systematically, for the first time, the circumgalactic environment of bright IRAS galaxies as defined by Soifer et al. (1989). While the role of gravitational interaction for luminous and ultraluminous IRAS galaxies has been well established by various studies, the situation is by far more obscure in the IR luminosity range of the bright IRAS sample, 10^{10}Lsol < Lfir < 10^{11} Lsol. To easily identify nearby companion galaxies, the bright IRAS sample was restricted to 87 objects with redshift range 0.008 < z < 0.018 and galactic latitude > 30^{o}. A control sample, selected from the Center for Astrophysics redshift survey catalogue, includes 90 objects matching the Bright IRAS sample for distribution of isophotal diameter, redshift, and morphological type. From a search of nearby companion galaxies within 250 Kpc on the second-generation Digitized Sky Survey (DSS-II), we found that the circumgalactic environment of the Bright IRAS galaxies contains more large companions than the galaxies in the optically selected control sample, and is similar to that of Seyfert 2 galaxies. We found a weak correlation over a wide range of far IR luminosity (10^9 Lsol < Lfir < 10^{12.5}Lsol) between projected separation and Lfir, which confirms a very close relationship between star formation rate of a galaxy and the strength of gravitational perturbations. We also find that the far IR colors depend on whether a source is isolated or interacting. Finally, we discuss the intrinsic difference and evolution expectations for the bright IRAS galaxies and the control sample, as well as the relationship between starbursting and active galaxies.Comment: 10 pages, 5 figs, 2 tables. Accepted for publication in Ap

The Murmur of the Sleeping Black Hole: Detection of Nuclear Ultraviolet Variability in LINER Galaxies

LINER nuclei, which are present in many nearby galactic bulges, may be the manifestation of low-rate or low-radiative-efficiency accretion onto supermassive central black holes. However, it has been unclear whether the compact UV nuclear sources present in many LINERs are clusters of massive stars, rather than being directly related to the accretion process. We have used HST to monitor the UV variability of a sample of 17 galaxies with LINER nuclei and compact nuclear UV sources. Fifteen of the 17 galaxies were observed more than once, with two to five epochs per galaxy, spanning up to a year. We detect significant variability in most of the sample, with peak-to-peak amplitudes from a few percent to 50%. In most cases, correlated variations are seen in two independent bands (F250W and F330W). Comparison to previous UV measurements indicates, for many objects, long-term variations by factors of a few over decade timescales. Variability is detected in LINERs with and without detected compact radio cores, in LINERs that have broad H-alpha wings detected in their optical spectra (``LINER 1's''), and in those that do not (``LINER 2s''). This variability demonstrates the existence of a non-stellar component in the UV continuum of all types, and sets a lower limit to the luminosity of this component. We note a trend in the UV color (F250W/F330W) with spectral type - LINER 1s tend to be bluer than LINER 2s. This trend may indicate a link between the shape of the nonstellar continuum and the presence or the visibility of a broad-line region. In one target, the post-starburst galaxy NGC 4736, we detect variability in a previously noted UV source that is offset by 2.5" (60 pc in projection) from the nucleus. This may be the nearest example of a binary active nucleus, and of the process leading to black hole merging.Comment: accepted to Ap

The bremsstrahlung equation for the spin motion in LHC

The influence of the bremsstrahlung on the spin motion is expressed by the equation which is the analogue and generalization of the Bargmann-Michel-Telegdi equation. The new constant is involved in this equation. This constant can be immediately determined by the experimental measurement of the spin motion, or it follows from the classical limit of quantum electrodynamics with radiative corrections.Comment: 9 page

Bargmann-Michel-Telegdi equation and one-particle relativistic approach

A reexamination of the semiclassical approach of the relativistic electron indicates a possible variation of its helicity for electric and magnetic static fields applied along its global motion due to zitterbewegung effects, proportional to the anomalous part of the magnetic moment.Comment: 10 pages, LATEX2E, uses amsb

Examining the Seyfert - Starburst Connection with Arcsecond Resolution Radio Continuum Observations

We compare the arcsecond-scale circumnuclear radio continuum properties between five Seyfert and five starburst galaxies, concentrating on the search for any structures that could imply a spatial or causal connection between the nuclear activity and a circumnuclear starburst ring. No evidence is found in the radio emission for a link between the triggering or feeding of nuclear activity and the properties of circumnuclear star formation. Conversely, there is no clear evidence of nuclear outflows or jets triggering activity in the circumnuclear rings of star formation. Interestingly, the difference in the angle between the apparent orientation of the most elongated radio emission and the orientation of the major axis of the galaxy is on average larger in Seyferts than in starburst galaxies, and Seyferts appear to have a larger physical size scale of the circumnuclear radio continuum emission. The concentration, asymmetry, and clumpiness parameters of radio continuum emission in Seyferts and starbursts are comparable, as are the radial profiles of radio continuum and near-infrared line emission. The circumnuclear star formation and supernova rates do not depend on the level of nuclear activity. The radio emission usually traces the near-infrared Br-gamma and H2 1-0 S(1) line emission on large spatial scales, but locally their distributions are different, most likely because of the effects of varying local magnetic fields and dust absorption and scattering.Comment: 21 pages, 10 figures. Accepted for publication in the Astronomical Journa

Analysis of the Interaction Effects in the Southern Galaxy Pair Tol1238-364 and ESO381-G009

In the context of the connection among galaxy-galaxy interaction, starbursts and nuclear activity, we present and discuss a quantitative morphological analysis based on BVR images and a detailed spectroscopic investigation of two interacting galaxies, the Seyfert 2 Tol1238-364 (IC 3639) and its companion ESO381-G009, forming a triple system with ESO381-G006. Broad-band optical photometry is complemented by Halpha imaging, which provides information about the distribution of star forming regions across the galaxies. Long-slit spectroscopic data obtained at different position angles of the slit are employed to determine the physical conditions of circumnuclear and extranuclear regions. A mixture of thermal and non-thermal ionizing radiation is found in the surroundings of the nucleus of Tol1238-364 and the energy budget supports the presence of a circumnuclear starburst.Several regions in both the galaxies show anomalous line ratios: additional ionization by shock-heating and low ionization of some extranuclear HII regions are suggested as possible explanations. An analysis of the emission-line profiles reveals the presence of a broad Halpha component in the nuclear region of Tol1238-364. Independent estimates of the star formation rates (SFR) were obtained through flux-calibrated Halpha-images and FIR emission in the four IRAS bands. Overall SFR densities have been compared with the SFR densities derived from Halpha emission in the individual regions of the galaxies sampled by long-slit spectra. In both galaxies an enhancement of the star formation activity with respect to isolated galaxies is revealed. The prevalence of starburst or nuclear activity has been examined through FIR color indices. The interaction scenario is discussed on the basis of the observed galaxy properties.Comment: Tentatively scheduled for publication in ApJS, v184 n2 October 2003 issue. A version with full resolution figures is available as unedited preprint at http://www.journals.uchicago.edu/ApJ/future.htm

On the Origin of Broad Fe K alpha and Hi H alpha Lines in AGN

We examine the properties of the Fe emission lines that arise near 6.4 keV in the ASCA spectra of AGN. Our emphasis is on the Seyfert 1 galaxies where broad and apparently complex Fe K alpha emission is observed. We consider various origins for the line but focus on the pros and cons for line emitting accretion disk models. We develop a simple model of an illuminated disk capable of producing both X-ray and optical lines from a disk. The model is able to reproduce the observed Fe K alpha FWHM ratio as well as the radii of maximum emissivity implied by the profile redshifts. The overall profile shapes however do not fit well the predictions of our disk illumination model nor do we derive always consistent disk inclinations for the two lines. We conclude that the evidence for and against an accretion disk origin for the Fe K alpha emission is equal at best. The bulk of the data requires a very disparate set of line fits which shed little light on a coherent physical model. We briefly consider alternatives to disk emission models and show that a simple bicone model can reproduce the FE line profiles equally well.Comment: 29 pages, 6 tables, 6 figures. Submitted for publication in the Astrophysical Journal part

Sex dependent risk factors for mortality after myocardial infarction : individual patient data meta-analysis

Background. Although a number of risk factors are known to predict mortality within the first years after myocardial infarction, little is known about interactions between risk factors, whereas these could contribute to accurate differentiation of patients with higher and lower risk for mortality. This study explored the effect of interactions of risk factors on all-cause mortality in patients with myocardial infarction based on individual patient data meta-analysis. Methods. Prospective data for 10,512 patients hospitalized for myocardial infarction were derived from 16 observational studies (MINDMAPS). Baseline measures included a broad set of risk factors for mortality such as age, sex, heart failure, diabetes, depression, and smoking. All two-way and three-way interactions of these risk factors were included in Lasso regression analyses to predict time-to-event related all-cause mortality. The effect of selected interactions was investigated with multilevel Cox regression models. Results. Lasso regression selected five two-way interactions, of which four included sex. The addition of these interactions to multilevel Cox models suggested differential risk patterns for males and females. Younger women (ag

Swift X-Ray Observations of Classical Novae. II. The Super Soft Source sample

The Swift GRB satellite is an excellent facility for studying novae. Its rapid response time and sensitive X-ray detector provides an unparalleled opportunity to investigate the previously poorly sampled evolution of novae in the X-ray regime. This paper presents Swift observations of 52 Galactic/Magellanic Cloud novae. We included the XRT (0.3-10 keV) X-ray instrument count rates and the UVOT (1700-8000 Angstroms) filter photometry. Also included in the analysis are the publicly available pointed observations of 10 additional novae the X-ray archives. This is the largest X-ray sample of Galactic/Magellanic Cloud novae yet assembled and consists of 26 novae with super soft X-ray emission, 19 from Swift observations. The data set shows that the faster novae have an early hard X-ray phase that is usually missing in slower novae. The Super Soft X-ray phase occurs earlier and does not last as long in fast novae compared to slower novae. All the Swift novae with sufficient observations show that novae are highly variable with rapid variability and different periodicities. In the majority of cases, nuclear burning ceases less than 3 years after the outburst begins. Previous relationships, such as the nuclear burning duration vs. t_2 or the expansion velocity of the eject and nuclear burning duration vs. the orbital period, are shown to be poorly correlated with the full sample indicating that additional factors beyond the white dwarf mass and binary separation play important roles in the evolution of a nova outburst. Finally, we confirm two optical phenomena that are correlated with strong, soft X-ray emission which can be used to further increase the efficiency of X-ray campaigns.Comment: Accepted to ApJ Supplements. Full data for Table 2 and Figure 17 available in the electronic edition. New version of the previously posted paper since the earlier version was all set in landscape mod