Posters

To be displayed during the whole Meeting

Session: Basic Plasma Processes and Numerical Methods

N^o	1^st Author	Title
01	M.C. DE JULI	Electrostatic waves in dusty plasmas with variable charge on dust particles
02	A. ESQUIVEL	MHD turbulent mixing layers
03	H. PEREZ ROJAS	Pressures and energies of vacuum in a magnetic field. Analogies an differences with Casimir effect
04	A. SERBETO	Excitation of strong wakefields by intense neutrino bursts in a magnetized electron-positron plasma
05	R. SILVA JR.	Relativistic H-theorem and nonextensive kinetic theory
06	I. SPASSOVSKA	Soliton and Double Layer Solutions for four component dusty plasmas

Session: Space and Solar Plasmas

N^o	1^st Author	Title
07	M.A. CORSINI	Hydrodynamic 2-D model of coronal mass ejections
08	J. COSTA	Inference of magnetic fields from solar flares
09	G. CRISTIANI	Magnetic reconnection at the origin of submillimeter radiation
10	D. FALCETA-GONÇALVES	The Origin of the magnetic fields divergence in coronal holes
11	N. FARBIASH	How is the diamagnetic effect relevant to stellar surface phenomena?
12	J.L. FERREIRA	Plasma sources for laboratory simulation of space and astrophysical plasma interaction with magnetic fields
13	G. GUERRERO	Exploring solar dynamo models with a bipolytropic density profile and a deep meridional flow
14	R.R. ROSA	Characterization of solar multi-scaling magnetic loop interactions
15	C. SELHORST	Study of active regions temporal evolution at 17 GHz
16	Y. SHIRATORI	Possibilities on radio bursts from extrasolar planets
17	P.J.A. SIMÕES	Microwave solar flare spectra of complex magnetic ambient
18	A. VASQUEZ	Solar Corona Magnetic Structure and Stagnated Wind Outflow

Session: Magnetic Fields in Star Formation and Evolution

N^o	1^st Author	Title
19	S. ALENCAR	Comparing MHD diskwind models and observations of the classical T Tauri star RW Aur
20	S. ALENCAR	Non-stationary magnetospheric accretion in the classical T Tauri star AA Tau
21	N. DRAKE	Magnetic fields and surface chemical abundances in the Ap stars
22	N.R. LANDIN	Theoretical values of the Rossby number for low-mass, rotating pre-main sequence stars
23	G. PINZÓN	Star-disk interaction in classical T Tauri stars
24	G. ROJAS	Magnetic fields in weak and post T Tauri stars
25	A.A. VIDOTTO	Alfvén waves in dusty winds of cool supergiant stars

Session: Compact Objects, Accretion Disks and Outflows

N^o	1^st Author	Title
26	M.P. ALLEN	Accretion Induced Collapses may give origin to magnetars
27	T. ANDREOLLA	Core magnetic fields in ultracompact radio sources
28	C. ARAÚJO	A simple magnetohydrodynamical model for formation of supermassive black holes in QSOs
29	S. BASTRUKOV	Electrodynamics of paramagnetic neutron star
30	C.G. BERNAL	Analytical production and collimation of astrophysical jets
31	B. BORGES	Cyclical period changes in cataclysmic variables: evidence of magnetic activity cycles in the mass-donor star
32	L.C.L. BOTTI	Modeling the radio flaring behavior of 3C273
33	L. BURDERI	Accretion and magneto-dipole emission in fast rotating neutron stars: new spin equilibrium lines
34	S. CABRIT	The importance of magnetic fields in protostellar jet-driven shocks
35	A. CAPRONI	Spin-induced and magnetically driven precession in active galactic nuclei
36	A.H. CERQUEIRA	Three-dimensional numerical simulations of rotating jets
37	G.H.R. DE ARAÚJO LIMA	A MHD model for the stellar disk wind of DR Tau
38	F. DE COLLE	The effect on no-axisymmetrical perturbations on the generation of jets from magnetized accretion disks
39	E.M. DE GOUVEIA DAL PINO	A mechanism for the superluminal ejections in microquasars: a jet/accretion disk symbiosis
40	M. DIAZ	Observations of the emission-line stochastic variability in accretion disks
41	T. DI SALVO	Constraints on the neutron star magnetic field of transient LMXBs from their luminosity in quiescence
42	P.-K. FUNG	Free-electron laser in pulsar magnetosphere
43	R.F. GONZÁLEZ	Numerical simulations of Eta Carina bipolar outflows
44	E LÓPEZ	Pulsar radio emission cutoffs
45	E. LÜDKE	Magnetic fields in the hotspotless jet of 3C200
46	M. MALHEIRO	General relativistic effects of strong magnetic fields on the gravitational force: a driving engine for bursts of gamma-rays in SGRs?
47	H. MOSQUERA CUESTA	Strongest gravitational waves from neutrino oscillations at supernova core bounce
48	A. PEREZ MARTINEZ	Quark matter in stars and quantum-magnetic collapse
49	R. PICANÇO	Charged stars and the anysotropic structure
50	N.R. ROBBA	Simultaneous study of 4U 1728-34 with Chandra and Rossi XTE
51	R. SAITO	Spectral mapping of intermediate polar DQ Herculis
52	R. SAITO	Probing physical conditions in accretion discs with eclipse mapping techniques
53	M.J. VASCONCELOS	Alfvénic heating of vertically isothermal accretion disks
54	C. ZHANG	On the bottom magnetic field and magnetosphere of the accreting neutron star

Session: Magnetized ISM

N^o	1^st Author	Title
55	J. ARANEDA	Parametric instabilities of Alfvén waves in interstellar clouds
56	S. BOLDYREV	Radio wave propagation in the non-Gaussian interstellar medium
57	G. HICKEL	The environment and magnetic field of cometary globule CG30
58	P. HILY-BLANT	Coherence and magnetic fields at the parsec scales of diffuse molecular clouds
59	T. KUDOH	Magnetic turbulence in a self-gravitationally stratified cloud
60	F. OLIVEIRA ALVES	A polarimetric study in the region containing the molecular cloud Lupus 1
61	A. PEREYRA	Magnetic fields and dispersion of polarization angles: IRAS Vela Shell
62	J.W. VILAS-BOAS	Polarization properties of condensations in Musca and their relation to star formation

Session: Magnetic Fields in Galaxies, the IGM, and the Early Universe

N^o	1^st Author	Title
63	R. BOHRER-ADORNES	Synchrotron ages in hotspots of CSS quasars and radiogalaxies
64	V. BUENROSTRO-LEITER	The Parker instability in a realistic galactic model
65	M.S. DOS SANTOS	Modeling the spectrum of gravitational waves in the primordial universe
66	E. FLORIDO	Magnetic fields and the dynamics of the outer disk of spiral galaxies
67	B. GAENSLER	Probing cosmic magnetism with the square kilometre array
68	B. GAENSLER	The magnetic field of the magellanic clouds
69	R.F. GONZÁLEZ	An anisotropic thermal conduction model for Dem L316 in the magellanic cloud
70	H. MAKI	Dissipation of magnetic flux in primordial gas clouds
71	H. NISHIKORI	Global three-dimensional MHD simulations of galactic gaseous disks
72	A.L. OLIVEIRA	The "geometric amplification" of the cosmic magnetic induction
73	M. TANAKA	Magnetohydrodynamic simulations of the Wiggle instability in spiral galaxies
74	E. TELLES	The [L-sigma] relation for HII galaxies

Poster Abstracts

Session: Basic Plasma Processes and Numerical Methods

Poster 01

ELECTROSTATIC WAVES IN DUSTY PLASMAS WITH VARIABLE

CHARGE ON DUST PARTICLES

Marcelo C. de Juli (1), Ruth S. Schneider (2), Luiz F. Ziebell (2), Vera Jatenco-Pereira (1)

(1) Instituto de Astronomia, Geofísica e Ciências Atmosféricas da Universidade de São Paulo

(2) Universidade Federal do Rio Grande do Sul-UFRGS

In this work, we present results obtained, using a kinetic approach, for parallel propagation of waves in a magnetized dusty plasma. In this magnetized plasma we consider embedded spherical dust grains with constant radius and variable charge. We consider that the principal process of dust charging is the capture of electrons and ions of the plasma and use a cross-section derived from the orbital motion limited theory to describe this process. We concentrate in electrostatic waves in a homogeneous magnetized dusty plasma. The dispersion relation and damping rates are obtained. We show that the usual resonant denominator, which occurs in plasmas without dust, is modified by the addition of a purely imaginary term which contains the collision frequency of electrons and ions with dust particles. We analyse the different mechanisms of damping, like Landau damping and damping that results from the electric charge variation of the dust particles, and study the competition between them.

Poster 02

MHD TURBULENT MIXING LAYERS

Alejandro Esquivel (1), Robert A. Benjamin (1-2), Jungyeon Cho (1-3),

Alex Lazarian (1), Samuel N. Leitner (4)

(1) University of Wisconsin-Madison

(2) University of Wisconsin-Whitewater

(3) Canadian Institute for Theoretical Astrophysics

(4) Wesleyan University

Observations of the interstellar medium (ISM) reveal a very complex picture: a highly turbulent medium, very rich in structure, all embedded in a magnetic field. To a large degree the structure of the ISM is controlled by the balance of mechanical heating and radiative cooling. At the interfaces between hot (~ 10⁶ K) and cooler (10²-10⁴) gas, turbulence is believed to play a crucial role by producing exchange of material. Within this so called "turbulent mixing layers" we expect gas at intermediate temperatures, thus facilitating radiative cooling. At the same time, magnetic fields are important because they can help to control or suppress instabilities that result in turbulent mixing. Previous models to diagnose physical parameters in turbulent mixing layers are based on steady-state, one dimensional, unmagnetized models. We present numerical simulations of turbulent mixing layers, obtained with a fully 3D magnetohydrodynamical (MHD) code, including radiative transfer. With our results is possible to predict various column density ratios (C IV/N V, Si IV/C IV, O VI/C IV) that will help interpretation of UV spectra.

Poster 03

PRESSURES AND ENERGIES OF VACUUM IN A MAGNETIC FIELD. ANALOGIES AN DIFFERENCES WITH CASIMIR EFFECT

Hugo Perez Rojas, Elizabeth Rodriguez Querts

Instituto de Cibernetica, Matematica y Fisica (ICIMAF)

We study vacuum pressures and energies for electron-positron vacuum zero point energy in a strong magnetic field B and for photon vacuum in comparison with Casimir effect, by following a common method. Vacuum becomes magnetized, and due to it, the pressure transversal to B is negative, whereas along B an usual positive pressure arises. Similarly, in addition to the usual negative Casimir pressure perpendicular to the plates, the existence of a positive pressure along the plates is predicted. Both vacua bear the property of leading to a negative energy-momentum tensor trace T ¹¹ < 0, which may lead to a repulsive gravity typical of dark energy. By assuming a space distribution of magnetic and/or Casimir domains, some consequences for astrophysics and cosmology are briefly discussed.

Poster 04

EXCITATION OF STRONG WAKEFIELDS BY INTENSE NEUTRINO BURSTS IN A MAGNETIZED ELECTRON-POSITRON PLASMA

A. Serbeto(1), L.A. Rios(1), J.T. Mendonça(2), P.K. Shukla(3), R. Bingham(4)

(1)IF/UFF - Brasil,

(2)GoLP/Instituto Superior Técnico, Portugal,

(3)Institut für Theoretical Physik IV, Ruhr-Universität Bochum, Germany,

(4)Rutherford Appleton Laboratory, England

It is well established that processes involving electron-positron plasmas are of significant importance in a variety of astrophysical environments, , like active galactic nuclei (AGN) and pulsar magnetospheres. Another very important material elements in the astrophysical settings are the neutrinos. The latter are produced by the core of stars and in very high explosive astrophysical situations such as those in supernova explosions and in ultra- relativistic pair plasma jets producing g-ray bursts (GRBs). Here, we are interested in nonlinear interactions of intense neutrino bursts with a relativistic magnetized pair-plasma. A classical fluid description is used to investigate these interactions between an electron-type neutrino burst and a collisionless magnetized electron-positron plasma. It is found that the symmetry between the electron and positron dynamics is broken due to the presence of intense neutrino bursts. The latter can excite strong upper- hybrid wakefields, which can produce unlimited acceleration of pairs across the external magnetic field direction via a surfatron mechanism. Implications of our results to the production of high-energy electrons and positrons in astrophysical environments are discussed.

Poster 05

RELATIVISTIC H-THEOREM AND NONEXTENSIVE KINETIC THEORY

Raimundo Silva (1), José Ademir Sales de Lima (2)

(1) Universidade do Estado do Rio Grande do Norte - UERN

(2) Instituto de Astronomia, Geofísica e Ciências Atmosféricas da Universidade de São Paulo

A proof of the relativistic H-theorem by including non-extensive effects is given. As it happens in the nonrelativistic limit, the molecular chaos hypothesis first considered by Boltzmann does not remain valid, and the second law of thermodynamics combined with a duality transformation implies that the q-parameter lies on the interval 0<q<2. It is also proved that the collisional equilibrium states (null entropy source term) are described by the relativistic q-power law extension of the exponential Juttner distribution, and as should be expected, in the limit v << c the Tsallis power law function is also recovered. As an illustration, we deduce the relativistic nonextensive equilibrium distribution for a dilute charged gas under the action of an electromagnetic field F^mn. All these results reduce to the standard ones in the extensive limit q ®1.

Poster 06

SOLITON AND DOUBLE LAYER SOLUTIONS FOR FOUR COMPONENT

DUSTY PLASMAS

Iglika Spassovska(1), Paulo Sakanaka(1), Padma Shukla(2)

(1) Instituto de Física "Gleb Wataghin", UNICAMP, Campinas, SP, Brazil.

(2) Institute für Theoretische Physik IV, Ruhr-Universität Bochum, D-44780 Bochum, Germany

In dusty plasmas with warm electrons, warm positive ions, and negative and positively charged cold dust grains which are simultaneously present, it is shown that stationary solutions of the fluid equations combined with Poisson's equation can be expressed in terms of the energy integral of a classical particle with a modified Sagdeev potential.We found that in four component dusty plasma there are changes in the nonlinear properties of the DAW. Compressive dust-acoustic solitons exist only when there is at least a trace of positively charged dust grains. The four fluid dusty plasma system, with both the negatively and positively charged dust grains, provides the ambient to excite double layers, Sakanaka et al. [1]. The latter is analyzed both analytically and numerically. The parametric regions of solitons, cavitons and double layers are given, and their profiles are displayed graphically. In particular, we have applied the theory in the laboratory plasma reported by Oohara et al. [2], and we can predict that a double layer might be possible to be launched if small quantity of ions was introduced in their experiment.

[1] P.H. Sakanaka and P.K. Shukla, Phys. Scripta, Vol T84, p.181 (2000). [2] W. Oohara, N. Tomioka, T. Hirata, R. Hatakeyama, and N. Sato, Proceedings of the 2000 International Congress on Plasma Physics, Quebec. Vol 1, p.116 (2000).

Session: Space and Solar Plasmas

Poster 07

HYDRODYNAMIC 2-D MODEL OF CORONAL MASS EJECTIONS

Marco A. Corsini (1,2), Adriana V.R. Silva (2)

(1) INPE - Instituto Nacional de Pesquisas Espaciais (2) CRAAM/Mackenzie - Centro de Radio Astronomia e Astrofísica Mackenzie

Coronal Mass Ejections (CME) are a large amounts of plasma expelled from the solar atmosphere. CMEs are threaded by magnetic fields and travel through the interplanetary space at supersonic velocities. As the ejection reaches Earth, it may interact with our magnetosphere and cause many undesired effects, such as damage to power transformers, satellites, navigation instruments, interference with long distance communications, lethal radiation to unprotected astronauts, among other problems. Since the physics of CMEs are yet not well understood, numerical models are used to study this phenomenon. Some numerical models of CMEs simulate the evolution of these structures in the interplanetary medium in order to predict their physical characteristics close to the Earth's magnetosphere. A hydrodynamic (HD) two-dimensional code, based on a method of finite differences called Modified Lax-Wendroff, was build to simulate CMEs in the interplanetary medium. This method solves the set of hydrodynamic differential equations in time and space; to increase numerical precision, it creates a new grid in an intermediate time calculating the new data in two steps. The initial condition is taken from the solution of the stationary radial HD equations using the Runge-Kutta method, which is the solar wind. The CME is then simulated as a pulse in the interplanetary medium in the initial condition. The boundary conditions are free, except for the first line (that contains the Sun) where the variables are kept constant and equal the initial solar wind values. The numerical results show the temporal and spatial evolution of a CME by the variation of its density, pressure, velocity. Comparison with observations from the LASCO experiment shows a good agreement with our numerical results.

Poster 08

INFERENCE OF MAGNETIC FIELDS FROM SOLAR FLARES

Joaquim Costa, (1) Antonio Rosal (2)

(1) INPE

(2) CRAAM-Mackenzie

The magnetic field induction present in the flare region can be inferred from the observed spectrum peak by the gyro synchrotron theory. For homogeneous magnetic field the spectrum peak is well defined and may be used for the inference of the field induction whenever we know the other important source parameters. However, the magnetic induction is the strongest dependence of the peak frequency and has been widely inferred from these spectra peak in solar flare analysis. The non homogeneous magnetic field may modify the spectrum width and peak mainly due to changes in the optically thick spectral index. Thus, for non homogeneous magnetic field the inferred induction may be interpreted as an effective value when the observation is fit, for example, by the four parameter fit-function given by most of solar flare analysis in the literature. Simple formulas are given for the gyro-synchrotron spectra peak in the literature where the peak is derived for the opacity equal one. This simplification causes the peak to be uncertain mostly for the cases where the optically thin spectral index is low. Besides, these simple equations are not applicable for spectra peak occurring below the tenth harmonic number of the electron gyro-frequency which excludes most of the observed flares. We present a simple expression for the magnetic induction in a self-absorbed gyro-synchrotron emission to infer it from the spectrum peak frequency as given by the spectrum least square fit instead of opacity equal one. Our equation is valid for a large range of parameters generally accepted for solar flare conditions including peak frequency below the tenth harmonic of the gyro-frequency.

Poster 09

MAGNETIC RECONNECTION AT THE ORIGIN OF SUBMILLIMETER RADIATION

G. Cristiani¹, G. Martínez¹, C.H. Mandrini¹, C.G. Giménez de Castro², A.V.R. Silva², E. Correia⁵, P. Kaufmann^2,3, M. Rovira¹, H. Levato⁴

1: Instituto de Astronomía y Física del Espacio, Buenos Aires, Argentina

2: Centro de Radio Astronomia e Astrofísica Mackenzie, Univ. Presbiteriana Mackenzie, Brazil.

3: Part time at CCS, Universidade Estadual de Campinas, Campinas, Brazil

4: Complejo Astronómico El Leoncito, San Juan, Argentina.

5: Centro de Radio Astronomia e Astrofísica Mackenzie, Instituto Nacional de Pesquisas Espaciais

During the 1B/M6.9 burst ocurred on November 28, 2001 at 1634 UT in NOAA AR 9715, radio radiation was observed up to 212 GHz almost simultaneously with a chromospheric mass ejection (surge) observed at Ha wavelength. Using MDI magnetograms we could derive the magnetic field under the linear force-free field assumption. A detailed analysis of the time evolution conectivity of the magnetic field gave us clues over the energy release and thus, the origin of the impulsive phenomena observed at submillimeter and optical wavelengths. We conclude that energy has been released at very low atmospheric heights, where densities are higher. We relate these reconnections with the impulsive radio burst, and also, with the fast pulses observed at submillimeter wavelengths. A Halo CME observed in LASCO images could be a byproduct of the surge.

Poster 10

THE ORIGIN OF THE MAGNETIC FIELDS DIVERGENCE IN CORONAL HOLES

Diego Falceta-Gonçalves & Vera Jatenco-Pereira

Instituto de Astronomia, Geofísica e Ciências Atmosféricas da Universidade de São Paulo

The solar atmosphere presents complexes magnetic structures, like loops and coronal holes, which are intrinsically bounded to the solar wind acceleration and driven mechanism. UVCS/SOHO and ground observations gave a new insight on the problem. Using H I Lyman alpha and O VI line intensity distributions it is possible to identify the coronal holes boundaries, showing a super-radial geometry with diverging factor f_max ranging from 6.0 to 7.5. It is not clear yet if other stars present such structures. However, the diverging magnetic fields play an important role in the stellar winds. In this work we develop a method for determining the magnetic divergence based on its tension generated by an increase in gas pressure at the wind basis.

Poster 11

HOW IS THE DIAMAGNETIC EFFECT RELEVANT TO STELLAR SURFACE PHENOMENA?

Netzach Farbiash, Raphael Steinitz

Ben-Gurion University, Beer-Sheva, Israel 84105

Charged particles at the surface of stars interact with diverging magnetic field structures. Together with gravity, a host of phenomena can occur. Closed magnetic structures can be the source of thermal as well as chemical abundance spots. High temperature coronal structures can also be present, even in stars without surface convection. Diverging open magnetic fields can result in stellar winds. Separation of charged and neutral particles in combination with dielectronic recombination can simulate chemically peculiar abundance effects. Further subtle effects such as T\_bot>T_| are observed in the fast solar wind close to the sun. Our sun, as the closest star, exhibits many of these effects and can thus be examined in detail.

Poster 12

PLASMA SOURCES FOR LABORATORY SIMULATION OF SPACE AND ASTROPHYSICAL PLASMA INTERACTION WITH MAGNETIC FIELDS

Jose Leonardo Ferreira, Israel da Silveira Rego, Guilherme Morais de Carvalho

Instituto de Física Universidade de Brasília

In this work we describe experiments that are been carried out at the Plasma Laboratory of UNB. The aim of these experiments is to investigate several plasma phenomena with relevance to space and astrpphysical plasmas using laboratory sources of low density and low temperature plasmas. In order to perform these studies we have constructed many types of gas ionization chambers to simulate on laboratory scales of ionospheric and magnetospheric plasmas. Density and temperature conditions of D , E and F layers are produced by cold electron plasmas. These plasmas are generated in a thermionic discharge inside a magnetic cage. The quiescent warm plasma drifts to a vacuum chamber where the cold plasma is formed. In order to simulate stellar winds we are developing Kaufmann type ion souce that can generate electrons and ions in the KeV range and a Hall plasma source that can generate low density and fast flowing plasma with ion energy of 500 eV. We are also performing studies to determine the importance of the Hall effect on the coronal mass ejection. These studies are relevant to space weather forecast. We also use a magnetized plasma source, where the plasma is produced by electron cyclotron ressonance in magnetic mirror throats. By using this experimental arragement it is possible to investigate plasma diffusion in magnetic fields geometries relevant to auroral arc formation and star accreation disks. The basic plasma diagnostic is made with probes and grid energy analysers and non pertubative mesurements of the ion dynamics in the mirror throat was carried out with spectroscopy technics. We are also using data processing techniques with computers that can be relevant for on board instrumentation control of satellites. In conclusion we have developed plasma devices that can be possibly used in laboratory simulation studies of space and astrophysical plasma phenomena and/or on the calibration plasma diagnostics for the next generation of scientific satellites of INPE (Brazillian Institute for Space Research).

Poster 13

EXPLORING SOLAR DYNAMO MODELS WITH A BIPOLYTROPIC DENSITY PROFILE FOR A DEEP MERIDIONAL FLOW

Gustavo Guerrero(1), Jose D. Munoz(2), Elisabete M. De Gouveia Dal Pino (1)

(1) Instituto de Astronomia, Geofísica e Ciências Atmosféricas da Universidade de São Paulo

(2) Depto. de fisica, Universidad Nacional de Colombia

Circulation-dominated solar dynamo models, which employ an helioseismically rotation profile and a fixed meridional flow, give a good approximation to the large scale solar magnetic phenomena: the 11-year cycle or the so called Hale`s law of polarities. Neverthless, the larger amplitude of the radial sh