Warm absorber, reflection and Fe K line in the X-ray spectrum of IC 4329A

Results from the X-ray spectral analysis of the ASCA PV phase observation of the Seyfert 1 galaxy IC 4329A are presented. We find that the 0.4 - 10 keV spectrum of IC 4329A is best described by the sum of a steep ($\Gamma \sim 1.98$) power-law spectrum passing through a warm absorber plus a strong reflection component and associated Fe K line, confirming recent results (Madejski et al. 1995, Mushotsky et al. 1995). Further cold absorption in excess of the Galactic value and covering the entire source is also required by the data, consistent with the edge-on galactic disk and previous X-ray measurements. The effect of the warm absorber at soft X-ray energies is best parameterized by two absorption edges, one consistent with OVI, OVII or NVII, the other consistent with OVIII. A description of the soft excess in terms of blackbody emission, as observed in some other Seyfert 1 galaxies, is ruled out by the data. A large amount of reflection is detected in both the GIS and SIS detectors, at similar intensities. We find a strong correlation between the amount of reflection and the photon index, but argue that the best solution with the present data is that given by the best statistical fit. The model dependence of the Fe K line parameters is also discussed. Our best fit gives a slightly broad ($\sigma \simeq 0.11 \pm 0.08$ keV) and redshifted (E $\simeq 6.20 \pm 0.07$ keV) Fe K line, with equivalent width $\simeq$ 89 $\pm$ 33 eV. The presence of a weak Fe K line with a strong reflection can be reconciled if one assumes iron underabundances or ionized reflection. We also have modeled the line with a theoretical line profile produced by an accretion disk. This yields results in better agreement with the constraints obtained from the reflection component.Comment: Accepted for publication in The Astrophysical Journal, 10th February 1996 issue; 24 pages and 8 figures + 1 table tared, compressed and uuencoded (with uufiles

Study of the Correlations Between the Highest Energy Cosmic Ray Showers and Gamma Ray Bursts

We examine the correlation between the arrival direction of ultra high energy cosmic ray showers and gamma ray bursts in the third BATSE catalog. We find no correlation between the two data sets. We also find no correlations between a pre-BATSE burst catalog and the Haverah Park Ultra High Energy shower set that cover approximately the same period of time.Comment: 1 uuencoded g-zipped postscript file containing text and figure

A numerical code to study the variability of Blazar emission

We present a numerical code, written in C, which can be used to simulate or to analyze the emission of Blazars over the entire electromagnetic spectrum. Our code can reproduce the following features: synchrotron emission, inverse Compton emission (Thomson Klein-Nishina regime) external Compton emission, accretion disk variability using a Cellular Automata algorithm, temporal evolution of the emitting plasma energy distribution, flaring phenomena, light curves in the rest and in the observer frame (taking account for time crossing effects). In this paper we will show mainly the accretion disk simulation, and the implications in the External Compton scenario.Comment: 4 pages, 2 eps figures. Poster to "The Physics of Relativistic Jets in the CHANDRA and XMM Era" (Bologna CNR). Proceedings to be published in New Astronomy Review

Asymptotic Flatness in Rainbow Gravity

A construction of conformal infinity in null and spatial directions is constructed for the Rainbow-flat space-time corresponding to doubly special relativity. From this construction a definition of asymptotic DSRness is put forward which is compatible with the correspondence principle of Rainbow gravity. Furthermore a result equating asymptotically flat space-times with asymptotically DSR spacetimes is presented.Comment: 11 page

The nature of the highest energy cosmic rays

Ultra high energy gamma rays produce electron--positron pairs in interactions on the geomagnetic field. The pair electrons suffer magnetic bremsstrahlung and the energy of the primary gamma ray is shared by a bunch of lower energy secondaries. These processes reflect the structure of the geomagnetic field and cause experimentally observable effects. The study of these effects with future giant air shower arrays can identify the nature of the highest energy cosmic rays as either gamma-rays or nuclei.Comment: 15 pages of RevTeX plus 6 postscript figures, tarred, gzipped and uuencoded. Subm. to Physical Review

Probing Exotic Physics With Cosmic Neutrinos

Traditionally, collider experiments have been the primary tool used in searching for particle physics beyond the Standard Model. In this talk, I will discuss alternative approaches for exploring exotic physics scenarios using high energy and ultra-high energy cosmic neutrinos. Such neutrinos can be used to study interactions at energies higher, and over baselines longer, than those accessible to colliders. In this way, neutrino astronomy can provide a window into fundamental physics which is highly complementary to collider techniques. I will discuss the role of neutrino astronomy in fundamental physics, considering the use of such techniques in studying several specific scenarios including low scale gravity models, Standard Model electroweak instanton induced interactions, decaying neutrinos and quantum decoherence.Comment: 11 pages, 6 figures; For the proceedings of From Colliders To Cosmic Rays, Prague, Czech Republic, September 7-13, 200