High Energy Variability Of Synchrotron-Self Compton Emitting Sources: Why One Zone Models Do Not Work And How We Can Fix It

With the anticipated launch of GLAST, the existing X-ray telescopes, and the enhanced capabilities of the new generation of TeV telescopes, developing tools for modeling the variability of high energy sources such as blazars is becoming a high priority. We point out the serious, innate problems one zone synchrotron-self Compton models have in simulating high energy variability. We then present the first steps toward a multi zone model where non-local, time delayed Synchrotron-self Compton electron energy losses are taken into account. By introducing only one additional parameter, the length of the system, our code can simulate variability properly at Compton dominated stages, a situation typical of flaring systems. As a first application, we were able to reproduce variability similar to that observed in the case of the puzzling `orphan' TeV flares that are not accompanied by a corresponding X-ray flare.Comment: to appear in the 1st GLAST symposium proceeding

Witnessing the gradual slow-down of powerful extragalactic jets: The X-ray -- optical -- radio connection

A puzzling feature of the {\it Chandra}--detected quasar jets is that their X-ray emission decreases faster along the jet than their radio emission, resulting to an outward increasing radio to X-ray ratio. In some sources this behavior is so extreme that the radio emission peak is located clearly downstream of that of the X-rays. This is a rather unanticipated behavior given that the inverse Compton nature of the X-rays and the synchrotron radio emission are attributed to roughly the same electrons of the jet's non-thermal electron distribution. In this note we show that this morphological behavior can result from the gradual deceleration of a relativistic flow and that the offsets in peak emission at different wavelengths carry the imprint of this deceleration. This notion is consistent with another recent finding, namely that the jets feeding the terminal hot spots of powerful radio galaxies and quasars are still relativistic with Lorentz factors $\Gamma \sim 2-3$. The picture of the kinematics of powerful jets emerging from these considerations is that they remain relativistic as they gradually decelerate from Kpc scales to the hot spots, where, in a final collision with the intergalactic medium, they slow-down rapidly to the subrelativistic velocities of the hot spot advance speed.Comment: Submitted in ApJ Letters on Jan. 14, 200

A Universal Scaling for the Energetics of Relativistic Jets From Black Hole Systems

Black holes generate collimated, relativistic jets which have been observed in gamma-ray bursts (GRBs), microquasars, and at the center of some galaxies (active galactic nuclei; AGN). How jet physics scales from stellar black holes in GRBs to the supermassive ones in AGNs is still unknown. Here we show that jets produced by AGNs and GRBs exhibit the same correlation between the kinetic power carried by accelerated particles and the gamma-ray luminosity, with AGNs and GRBs lying at the low and high-luminosity ends, respectively, of the correlation. This result implies that the efficiency of energy dissipation in jets produced in black hole systems is similar over 10 orders of magnitude in jet power, establishing a physical analogy between AGN and GRBs.Comment: Published in Science, 338, 1445 (2012), DOI: 10.1126/science.1227416. This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. Corrected typo in equation 4 of the supplementary materia

The Spectacular Radio-Near-IR-X-ray Jet of 3C 111: X-ray Emission Mechanism and Jet Kinematics

Relativistic jets are the most energetic manifestation of the active galactic nucleus (AGN) phenomenon. AGN jets are observed from the radio through gamma-rays and carry copious amounts of matter and energy from the sub-parsec central regions out to the kiloparsec and often megaparsec scale galaxy and cluster environs. While most spatially resolved jets are seen in the radio, an increasing number have been discovered to emit in the optical/near-IR and/or X-ray bands. Here we discuss a spectacular example of this class, the 3C 111 jet, housed in one of the nearest, double-lobed FR II radio galaxies known. We discuss new, deep Chandra and HST observations that reveal both near-IR and X-ray emission from several components of the 3C 111 jet, as well as both the northern and southern hotspots. Important differences are seen between the morphologies in the radio, X-ray and near-IR bands. The long (over 100 kpc on each side), straight nature of this jet makes it an excellent prototype for future, deep observations, as it is one of the longest such features seen in the radio, near-IR/optical and X-ray bands. Several independent lines of evidence, including the X-ray and broadband spectral shape as well as the implied velocity of the approaching hotspot, lead us to strongly disfavor the EC/CMB model and instead favor a two-component synchrotron model to explain the observed X-ray emission for several jet components. Future observations with NuSTAR, HST, and Chandra will allow us to further constrain the emission mechanisms.Comment: 12 pages, 9 figures, ApJ, in pres

Suppression of Anderson localization of light and Brewster anomalies in disordered superlattices containing a dispersive metamaterial

Light propagation through 1D disordered structures composed of alternating layers, with random thicknesses, of air and a dispersive metamaterial is theoretically investigated. Both normal and oblique incidences are considered. By means of numerical simulations and an analytical theory, we have established that Anderson localization of light may be suppressed: (i) in the long wavelength limit, for a finite angle of incidence which depends on the parameters of the dispersive metamaterial; (ii) for isolated frequencies and for specific angles of incidence, corresponding to Brewster anomalies in both positive- and negative-refraction regimes of the dispersive metamaterial. These results suggest that Anderson localization of light could be explored to control and tune light propagation in disordered metamaterials.Comment: 4 two-column pages, 3 figure

Anisotropy and oblique total transmission at a planar negative-index interface

We show that a class of negative index (n) materials has interesting anisotropic optical properties, manifest in the effective refraction index that can be positive, negative, or purely imaginary under different incidence conditions. With dispersion taken into account, reflection at a planar negative-index interface exhibits frequency selective total oblique transmission that is distinct from the Brewster effect. Finite-difference-time-domain simulation of realistic negative-n structures confirms the analytic results based on effective indices.Comment: to appear in Phys. Rev.

A multi-zone model for simulating the high energy variability of TeV blazars

We present a time-dependent multi-zone code for simulating the variability of Synchrotron-Self Compton (SSC) sources. The code adopts a multi-zone pipe geometry for the emission region, appropriate for simulating emission from a standing or propagating shock in a collimated jet. Variations in the injection of relativistic electrons in the inlet propagate along the length of the pipe cooling radiatively. Our code for the first time takes into account the non-local, time-retarded nature of synchrotron self-Compton (SSC) losses that are thought to be dominant in TeV blazars. The observed synchrotron and SSC emission is followed self-consistently taking into account light travel time delays. At any given time, the emitting portion of the pipe depends on the frequency and the nature of the variation followed. Our simulation employs only one additional physical parameter relative to one-zone models, that of the pipe length and is computationally very efficient, using simplified expressions for the SSC processes. The code will be useful for observers modeling GLAST, TeV, and X-ray observations of SSC blazars.Comment: ApJ, accepte

Protein detection by polymer optical fibers sensitized with overlayers of block or random copolymers

In this study a low cost and low complexity optical detection method of proteins is presented by employing a detection scheme based on electrostatic interactions, and implemented by sensitization of a polymer optical fiber (POF) surface by thin overlayer of properly designed sensitive copolymer materials with predesigned charges. This method enables the fast detection of proteins having opposite charge to the overlayer, and also the effective discrimination of differently charged proteins like lysozyme (LYS) and bovine serum albumin (BSA). More specifically, as sensitive materials here was used the block and the random copolymers of the same monomers, namely the block copolymer poly(styrene-b-2vinylpyridine) (PS-b-P2VP) and the corresponding random polymer poly(styrene-r-2-vinylpyridine) (PS-r-P2VP), of similar composition and roughly similar molecular weight. Moreover, this work focused on the comparison of the aforementioned sensitive materials regarding the way in which they can adapt on sensing optical platforms and constitute functional sensing bio-materials