$\parbox{150mm}{ {\LARGE\bf Chinese Journal of Astronomy and Astrophysics}\\ }$

Special Issue for Frascati Workshop 2003   (Vol. 3 Supplement)

ABSTRACTS

Multifrequency Astrophysics Today    p.1

F. Giovannelli¹, and L. Sabau-Graziati²

¹ Istituto di Astrofisica Spaziale e Fisica Cosmica, CNR - Sezione di Roma
   Area di Ricerca CNR di Roma-2, Via del Fosso del Cavaliere, 100, I 00133 Roma, Italy; franco@rm.iasf.cnr.it
² Departamento de Ciencias del Espacio y Tecnologías Electrónicas INTA
   Carretera de Ajalvir Km 4 - E 28850 Torrejon de Ardoz, Spain

Abstract
This paper reproduces the introductory talk of the workshop in which we presented several hot points of today astrophysics, which have been discussed in details during the workshop. We would like to demonstrate that the improvement on knowledge of the physics of the Universe is strictly related with multifrequency studies of diffuse and discrete cosmic sources.

Key words:   Multifrequency Astrophysics: cosmology, clusters of galaxies, AGNs, GRBs, radio pulsars, millisecond pulsars, cosmic counterparts of $\gamma$-ray sources

Download full paper in PDF

CP violations in the Universe    p.30

Giulio Auriemma

Universita degli Studi della Basilicata, Potenza, Italy; Giulio.Auriemma@cern.ch

Abstract
The origin of the asymmetry between matter and antimatter that is evident in our part of the Universe is one of the open questions in cosmology, because the CPT symmetry between matter and antimatter seems to be absolutely conserved at microscopic level. We repeat here the classical proofs which exclude the viability of a Universe baryon symmetric on the average, or the observed asymmetry as an initial conditions. The current understanding is that the asymmetry should have been dynamically generated before nucleosynthesis, by B, C, and CP violating processes, acting out of thermodynamical equilibrium, as suggested by Sakharov in the 70's. The physical realizations of these conditions would be possible, in principle, also in the framework of the Standard Model of elementary particles, but the present limits on the mass of the higgs particle exclude this possibility. Finally we present the model of baryogenesis through leptogenesis, which is allowed by a minimal extension of the Standard Model, which has the appeal of being testable in future long-baseline neutrino oscillation experiments.

Key words:   Cosmology: early universe, elementary particles

Download full paper in PDF

Recent results on microlensing    p.43

J-F. Glicenstein

DSM/DAPNIA/SPP
CEA-Saclay, 91191 Gif-sur-Yvette, France; glicens@hep.saclay.cea.fr

Abstract
This paper reviews recent results on Galactic structure obtained by microlensing surveys. The status of searches for compact Galactic halo objects towards the Magellanic Clouds and M31 is given. Recents measurements of the microlensing optical depth towards the Galactic Centre are reported.

Key words:   dark matter - Galaxy: fundamental parameters - Galaxy: halo - gravitational lensing - surveys

Download full paper in PDF

Progress in Understanding the Diffuse UV Background    p.53

Richard Conn Henry

Center for Astrophysical Sciences, The Johns Hopkins University, Baltimore, Maryland 21218, USA; henry@jhu.edu

Abstract
The ultraviolet spectrometers aboard the Voyager spacecraft have been used to delineate, for the first time, the appearance of the diffuse component of the sky at wavelengths about 1000 Å to 1100 Å. To measure the diffuse background requires use of appropriate instrumentation. I explain how difficult it has been to ensure that investigation of the UV diffuse background radiation is carried out with instrumentation that is, in fact, capable of making the necessary measurements successfully.

Key words:  techniques: ultraviolet - background radiation: ultraviolet

Download full paper in PDF

The Hubble Space Telescope: Past, Present, and Future    p.64

Nino Panagia

ESA/Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA: panagia@stsci.edu

Abstract
I present and illustrate some of the most recent  results and the plans for future observations, including the current studies of solar system planets, the extensive imaging of the Helix Nebula, the detection of superluminally expanding light echoes around the newly discovered variable star V838 Mon, the repeated measurements of the collision of SN 1987A ejecta with its inner circumstellar ring, that show a marked increase of high energy interactions, the study of M31 halo stellar populations and the puzzle of their origin, and the plans for the  Ultra-Deep Field observations that will probe the Universe to an unprecedented depth.

Key words:  planets and satellites: individual (Mars, Neptune) -- planetary nebulae: individual (NGC 7293) -- novae, cataclysmic variables -- supernovae: individual (1987A) -- galaxies: halos -- cosmology: early universe

Download full paper in PDF

Muon and Tau Neutrinos Spectra from Solar Flares    p.75

Daniele Fargion and Federica Moscato

Physics Department and Infn, Rome University La Sapienza, P.le A. Moro,2, 00185 Rome, Italy; daniele.fargion@roma1.infn.it

Abstract
Most power-full solar flare as the ones occurred on 23th February 1956, September 29th 1989, 28th October and on 2nd-4th November 2003 are sources of cosmic rays, X, gamma and neutrino bursts. These flares took place both on front or in the edge and in the hidden solar disk. The 4th November event was the most powerful X event in the highest known rank category X28 just at horizons. The observed and estimated total flare energy ( ${E}_{\rm FL} \simeq {10}^{31}\div {10}^{33}$erg) should be a source of a prompt secondary neutrino burst originated, by proton-proton-pion production on the sun itself; a more delayed and spread neutrino flux signal arise by the solar charged flare particles reaching the terrestrial atmosphere. These first earliest prompt solar neutrino burst might be observed, in a few neutrino clustered events, in present or future largest neutrino underground detectors as Super-Kamiokande one, in time correlation with the X-Radio flare. The onset in time correlation has great statistical significance. Our first estimate on the neutrino number events detection at the Super-Kamiokande II Laboratory for horizontal or hidden flare is found to be few events: ${N}_{{\rm eV}_{\bar{\nu}_{e}}}\simeq 0.63{\eta_{e}}(\frac{\langle {E}_{\nu}\rangle}{35 {\rm MeV}}) (\frac{\langle {E}_{\rm FL}\rangle}{{10}^{31} {\rm erg}})$; and ${N}_{{\rm eV}_{\bar{\nu}_{\mu}}} \simeq 3.58(\frac{\langle {E}_{{\nu}_{\mu}}... ...\rm MeV}) (\frac{\langle {E}_{\rm FL}\rangle}{{10}^{31} \rm erg}){\eta_{\mu}}$, where ${\eta}\simeq 1$, ${E}_{{\nu}_{\mu}} > 113$MeV. Our first estimates of neutrino signals in largest underground detectors hint for few events in correlation with X, gamma, radio onser. Our approximated spectra for muons and taus from these rare solar eruption are shown over the most common background. The muon and tau signature is very peculiar and characteristic over electron and anti-electron neutrino fluxes. The rise of muon neutrinos will be detectable above the minimal muon threshold $E_{\nu}$$\simeq 113$MeV energy, or above the pion and $\Delta \degr$ thresholds ( $E_{\nu}\simeq 151$ and 484MeV). Any large neutrino flare event record might also verify the expected neutrino flavour mixing leading to a few as well as a comparable, ${\nu}_{e}$, ${\nu}_{\mu}$, $\bar{\nu}_{e}$, $\bar{\nu}_{\mu}$ energy fluence and spectra. The rarest tau appearence will be possible only for hardest solar neutrino energies above 3.471GeV.

Download full paper in PDF

Cosmology and the physics of our universe    p.87

S. Colafrancesco

INAF - Osservatorio Astronomico di Roma, Monteporzio (Roma) I-00040, Italy; cola@mporzio.astro.it

Abstract
Cosmology is undertaking the character of a precision science. Our hope to understand the details of the cosmological evolution contends with larger and larger data amounts and more and more refined data analysis and theoretical techniques. An approach of thoroughly conscious ignorance is the prelude to every real advance of knowledge in this field.

Key words:  Cosmology

Download full paper in PDF

Keys to Cosmology - Clusters of Galaxies    p.97

Sabine Schindler

Institut für Astrophysik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria; Sabine.Schindler@uibk.ac.at

Abstract
We review several aspects of clusters of galaxies and their application to cosmology. We present first results of numerical simulations of the dynamics of the intra-cluster gas and of different interaction processes between cluster galaxies and the intra-cluster gas. In particular metallicity maps are very useful to determine the importance of the different interaction processes. Also mass determination methods and possible sources for uncertainties in the measurements are shown.

Key words:   galaxies: clusters: general, interactions, cosmological parameters, dark matter, X-rays: galaxies: clusters, hydrodynamics

Download full paper in PDF

The evolution of the Light Elements, Be and B (also Li), in the Galaxy    p.105

John E. Beckman^1,2 and Emilio Casuso¹

¹ Instituto de Astrofisica de Canarias, 38200, La Laguna, Tenerife, Spain; eca@ll.iac.es
² Consejo Superior de Investigaciones Cientificas, Madrid, Spain

Abstract
We consider the evolution of the light elements, especially beryllium and boron but also lithium, in the Galaxy as derived from observations within 1kpc of the Sun. The interest in Li has much to do with the evaluation of the universal baryon abundance via primordial nucleosynthesis, but the difficulties of interpretation have led to the need to understand Li synthesis within the Galaxy, and this entails understanding many processes, both stellar and interstellar. In the case of Be, and B although measurable abundances produced in the primaeval fireball were predicted in certain models, these are largely (but not totally) discounted observationally. However understanding the evolution of Be and B as tracers of Galactic chemical evolution is important. While most experts in nucleosynthesis have concentrated on the linear relation between B/Be and Fe, (or O) in the Galactic halo, and taken disc evolution rather for granted, we show that it is vital to use a valid chemical evolution model for the disc to explain the observations. We present such a model, and emphasize its implications for the infall of low metallicity gas to the disc as the driving element in star formation during the whole disc lifetime.

Key words:   Galaxy: Disc, Gas accretion, Evolution, Nuclear Reactions, Nucleosynthesis, Abundances

Download full paper in PDF

The Quest for Primordial Stellar Populations and the James Webb Space Telescope    p.115

Nino Panagia

ESA/Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA; panagia@stsci.edu

Abstract
The NASA/ESA/CSA James Webb Space Telescope (JWST) will be the successor to the Hubble Space Telescope and may be launched as early as mid-2011. The key scientific goals for JWST are discovering and understanding the formation of the first stars and galaxies, the evolution of galaxies and the production of elements by stars, and the process of star and planet formation. Within this context, we discuss the expected properties of the first stellar generations in the Universe. We find that it is possible to discern truly primordial populations from the next generation of stars by measuring the metallicity of high-z star forming objects. The very low background of JWST will enable it to image and study first-light sources at very high redshifts, whereas its relatively small collecting area limits its capability in obtaining spectra of $z\sim$10-15 first-light sources to either the bright end of their luminosity function or to strongly lensed sources. With a suitable investment of observing time JWST will be able to detect individual Population III supernovae, thus identifying the very first stars that formed in the Universe.

Key words:  space vehicles: instruments -- early universe -- galaxies: star clusters -- supernovae: general

Download full paper in PDF

The multifrequency astrophysics of galaxy clusters    p.126

S. Colafrancesco

INAF - Osservatorio Astronomico di Roma, Monteporzio (Roma) I-00040, Italy; cola@mporzio.astro.it

Abstract
We discuss the evidence and the physical relevance of the astrophysical phenomena (of thermal and non-thermal origin) occurring in galaxy clusters as obtained from multi-frequency observations, from radio to gamma-rays.

Key words:  Cosmology -- Galaxies: clusters

Download full paper in PDF

AGN Jet Interactions with the Intracluster Medium    p.137

J.H. Beall^1,2,3, John Guillory², D. V. Rose⁴, Sabine Schindler⁵, and S. Colafrancesco⁶

¹ E.O. Hulburt Center for Space Research, Naval Research Laboratory, Washington, DC
² Center for Earth Observing and Space Research, School for Computational Sciences, George Mason University, Fairfax, VA
³ St. John's College, Annapolis, MD
⁴ Mission Research Corporation, Albuquerque, NM
⁵ Institut für Astrophysik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
⁶ INAF - Osservatorio Astronomico di Roma, Monteporzio (Roma), I-00040, Italy; beall@sjca.edu

Abstract
Clusters of galaxies contain large ellipticals near their cores. Elliptical galaxies in the centers of these clusters are often found to be the source of large-scale jets that propagate outward into the intracluster medium. These jets are thought to be produced by accretion-powered processes in the active galactic nuclei (AGN) at the centers of some giant ellipticals. In this paper, we discuss the origin of these jets and the likely consequences of their interactions with the intracluster medium in clusters of galaxies.

Key words:  jets: active galaxies: intracluster medium

Download full paper in PDF

A New Population of Radio Quasars    p.147

Paolo Padovani^1,2, Eric Perlman^1,3, Hermine Landt^1,4, Paolo Giommi⁵, and Matteo Perri^5,6

¹ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA; Paolo.Padovani@eso.org
² ESA Space Telescope Division
³ Joint Center for Astrophysics, University of Maryland, 1000 Hilltop Circle, Baltimore, MD 21250, USA (current address)
⁴ Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg, Germany
⁵ ASI Science Data Center, ASDC, c/o ESRIN, Via G. Galilei, I-00044 Frascati, Italy
⁶ Dipartimento di Fisica, Università la Sapienza, Piazzale A. Moro 2, Roma, Italy

Abstract
We present the discovery of a new population of radio quasars. Unlike previously known sources, whose X-ray emission is due to (flat) inverse Compton radiation, these objects are characterized by (steep) synchrotron emission in the X-ray band, with a broad-band spectral energy distribution similar to that of BL Lacs with high energy synchrotron peaks. We discuss how this new class was discovered, the class properties, and the implications of its existence for our understanding of jet physics and active galactic nuclei in general.

Key words:  BL Lacertae objects: general -- galaxies: active -- quasars: general -- radiation mechanisms: nonthermal -- radio continuum: galaxies -- X-rays: galaxies

Download full paper in PDF

Broad Iron Lines in Active Galactic Nuclei    p.157

J. Wilms¹, E. Kendziorra¹, and C. S. Reynolds²

¹ Institut für Astronomie und Astrophysik, Abt. Astronomie, Sand 1, 72076 Tübingen, Germany; wilms@astro.uni-tuebingen.de
Present address: Department of Physics, University of Warwick, Coventry, CV4 7AL, U.K.
² Department of Astronomy, University of Maryland, College Park, MD 20742, USA

Abstract
The Fe K$\alpha$ lines seen in many Active Galactic Nuclei (AGN) are thought to originate close to the central supermassive black hole. In this review we summarize the physics of the fluorescent line formation and show that Fe K$\alpha$ line profile observations can be used to probe relativistic effects in the vicinity of the black hole, concentrating on recent results from .

Key words:  accretion, accretion physics -- black hole physics

Download full paper in PDF

Observational signatures of the warm-hot intergalactic medium and X-ray absorption lines by the halo of our Galaxy    p.169

Kazuhisa Mitsuda

Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa 229-8510, Japan; mitsuda@astro.isas.jaxa.jp

Abstract
Approximately 30% to 50% of the total baryons of the present universe are considered to take a form of warm/hot intergalactic medium (WHIM) and to have evaded direct detection. The WHIM of T=10⁶-10⁷K is most likely detected through absorption and emission lines of and . The equivalent widths of the absorption lines are typically 0.4eV, which is consistent with the absorption lines having redshifts indistinguishable from zero observed in the spectra of a few bright active galactic nuclei (AGN). However, from the midplane  density estimated from absorption line in the Galactic X-ray source, , we consider that a significant fraction of warm/hot plasma responsible for the AGN absorption lines is located in our Galaxy rather than in the local group. For a systematic study of the WHIM, survey-type observations detecting emission lines are necessary. While the typical surface brightness of and emission lines is below the detection limit of present and proposed future missions, an unambiguous detection will be feasible with a small X-ray mission dedicated for this purpose. Our proposed mission, DIOS (Diffuse Intergalactic Oxygen Surveyor), is sensitive to the WHIM of temperatures T=10⁶-10⁷K and can survey about 0.1sr area to the depth of cosmological redshift z<0.3 in two years.

Key words:  X-rays: ISM - cosmology: miscellaneous

Download full paper in PDF

High Velocity Gas Outflows from H II regions in Disc Galaxies    p.181

Relaño M. ¹, Beckman J. E.², and Rozas M.³

¹ Instituto de Astrofísica de Canarias, C/Vía Láctea s/n, 38200 La Laguna, Tenerife, Spain; mpastor@ll.iac.es
² Instituto de Astrofísica de Canarias, C/Vía Láctea s/n, 38200 La Laguna Tenerife, Spain
³ Observatorio Astronómico Nacional (UNAM), Apartado Postal 877 Ensenada, B.C., México

Abstract
We analyze the emission line profiles of the region populations in three disc spiral galaxies and find evidence of wing features at 40-90  from the central peak in a significant fraction of regions. We explain the wing features as due to a shell expanding inside the region, quantify the energy involved and present two possible mechanisms to drive the expanding shell.

Key words:   regions - ISM: jets and outflows - stars: mass loss

Download full paper in PDF

An X-ray Perspective on a Gamma-Ray Mission    p.186

Niels Lund

Danish Space Research Institute Juliane Maries Vej 30, DK-2100 Copenhagen Ø, Denmark; nl@dsri.dk

Abstract
The most recent astrophysics mission of ESA is INTEGRAL, a mission dedicated to gamma-ray astronomy (Winkler et al. 2003). INTEGRAL carries two gamma-ray instruments: the imager, IBIS, and the spectrometer, SPI, and in addition an optical monitor, OMC, and an X-ray monitor, JEM-X. INTEGRAL is an observatory mission with 70% of the observation time available to the general astronomical community through a peer-reviewed selection process. This paper describes the INTEGRAL mission primarily as seen from the JEM-X perspective.

Key words:  techniques: Coded mask telescopes - stars: X-ray and gamma-ray sources - stars: individual: Crab Nebula

Download full paper in PDF

X-ray Source Populations in Galaxies    p.193

G. Fabbiano

Harvard-Smithsonian Center for Astrophysics 60 Garden St., Cambridge MA 02138, USA; gfabbiano@cfa.harvard.edu

Abstract
This paper gives a short review of recent studies of the X-ray source populations of nearby galaxies. A more complete review of this subject can be found in Fabbiano & White (2003), from where this talk was partially extracted.

Key words:  X-rays: sources; galaxies: X-rays

Download full paper in PDF

X-Ray Binaries: A Laboratory for Frontier Physics    p.202

F. Giovannelli¹, and L. Sabau-Graziati²

¹ Istituto di Astrofisica Spaziale e Fisica Cosmica, CNR - Sezione di Roma
   Area di Ricerca CNR di Roma-2, Via del Fosso del Cavaliere, 100, I 00133 Roma, Italy; franco@rm.iasf.cnr.it
² Departamento de Ciencias del Espacio y Tecnologías Electrónicas INTA
   Carretera de Ajalvir Km 4 - E 28850 Torrejón de Ardóz, Spain

Abstract
The goal of this paper is to discuss the behaviour of the X-ray binary systems, in order to present to the readers an updated panorama of this important class of X-ray sources. They have in common the binary nature, but rather different characteristics: millisecond pulsations in low mass binary systems, seconds-hundreds seconds pulsations in transient high mass X-ray systems, pulsations limited in a narrow $\sim$6-12s band in the enigmatic class of systems named anomalous X-ray pulsars. However, all these systems are characterized by a neutron star as collapsed object. A few words will be devoted also to those systems having a black hole as collapsed object. Some comments on radio pulsars-SNRs and X-ray pulsars-SNRs associations will be given too.

Key words:  X-ray binary systems: High mass binary systems, Low mass binary systems, Radio pulsars, SNRs/X-ray pulsars association

Download full paper in PDF

X-ray sources in globular clusters    p.225

Frank Verbunt and Cees Bassa

Astronomical Institute University Utrecht, Postbox 80000, 3508 TA Utrecht, the Netherlands; verbunt@astro.uu.nl, bassa@astro.uu.nl

Abstract
The study of X-ray sources in globular clusters is in very rapid progress, thanks to the combined observations of Chandra and XMM X-ray observatories, and the Hubble Space Telescope. In addition to the low-mass X-ray binaries known since the early 1970s, quiescent X-ray binaries, cataclysmic variables, radio pulsars, and magnetically active binaries can now be identified and studied in X-rays and optical. This improves our knowledge of the population of binaries in globular clusters.

Key words:  stars: X-ray sources - globular clusters

Download full paper in PDF

Accretion Flow in Magnetic Cataclysmic Variables    p.235

Kinwah Wu¹, Mark Cropper¹, Gavin Ramsay¹, Curtis Saxton², and Chris Bridge¹

¹ Mullard Space Science Laboratory, University College London, Holmbury St Mary, Surrey, RH5 6NT, United Kingdom; kw@mssl.ucl.ac.uk
² Max-Planck-Institute für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany

Abstract
The standard model of the post-shock accretion flow in mCVs is discussed. We present some results of the current study of two-temperature flows in mCVs. New observations supporting the standard model are presented. Recent developments in the studies of the global properties of the accretion stream are briefly discussed.

Key words:  accretion, accretion disks - stars: binaries - stars: cataclysmic variables - X-rays: binaries

Download full paper in PDF

News from Galactic Black Holes    p.245

Janusz Ziókowski Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warsaw, Poland; jz@camk.edu.pl

Abstract
Present status of the possible black hole microlensing events and the present understanding of high frequency quasi-periodic oscillations in systems containing black hole candidates (BHCs) are briefly discussed. The growing evidence for the presence of the event horizons around some compact objects is reviewed. Finally, the news from four individual objects (SS 433, GX 339-4, CI Cam and Cyg X-3) are presented and the updated list of BHCs, containing 49 objects is given.

Key words:  -- stars: X-ray binaries -- stars: black holes -- stars: individual: SS 433, GX 339-4, CI Cam, Cyg X-3

Download full paper in PDF

X-ray binaries in the Milky Way and other galaxies    p.257

Hans-Jakob Grimm¹, Marat Gilfanov^2,3, and Rashid Sunyaev^2,3

¹ Center for Astrophysics, 60 Garden Street, MS-29, Cambridge 02138, USA; hgrimm@head-cfa.cfa.harvard.edu
² Max-Planck-Institut für Astrophysik Karl-Schwarzschild-Str. 1, 85741 Garching, Germany
³ Space Research Institute of Russian Academy of Sciences, Profsoyuznaya 84/32, 117810 Moscow, Russia

Abstract
We performed a study of the X-ray binary population in the Milky Way. The results of this study, spatial distribution and in particular luminosity function, can be used for comparison with the X-ray binary populations of other galaxies. In the second part we give an example by investigating the connection between the star formation rate and the high mass X-ray binary population in galaxies observed by CHANDRA.

Key words:  X-rays: binaries - Galaxies: Milky Way - Luminosity function

Download full paper in PDF

Magnetic fields of accreting X-ray pulsars    p.270

Rüdiger Staubert

Institut für Astronomie und Astrophysik, Universität Tübingen, Sand 1, D-72076 Tübingen, Germany; staubert@astro.uni-tuebingen.de

Abstract
The status of the knowledge about magnetic fields of neutron stars in accreting X-ray binaries through the measurement of cyclotron lines (Cyclotron Resonance Scattering Features -- CRSF) is reviewed. A systematic search for cyclotron lines through observations with the Rossi X-ray Timing Explorer (RXTE) and a uniform analysis have led to a list of 10 objects showing one or more line feature(s) in phase averaged spectra (Coburn 2001, Coburn et al. 2002a). Another 3 objects are known from observations by Ginga, HEXE and OSSE, but were not observed by RXTE. For 12 further objects upper limits have been set from RXTE observations (Coburn et al. 2002b). Four objects show more than one line, with 4U 0115+63 showing up to five lines. The range of magnetic fields in these objects is $\sim (1\ldots 5) 10^{12}$Gauss. There are a number of significant correlations between parameters describing the line and the continuum spectrum, as well as among the line parameters themselves. The physics of these correlations is not well understood.

Key words:  stars: neutron stars, X-ray binaries - magnetic fields: super strong

Download full paper in PDF

X-ray Emission from Galactic Plane    p.281

Ken Ebisawa^1,2,3, S. Yamauchi⁴, A. Bamba⁵, M. Ueno⁵, and A. Senda ⁵

¹ INTEGRAL Science Data Centre, chemin d'Écogia 16, Versoix, 1290 Switzerland; ebisawa@obs.unige.ch
² Code 662, NASA/GSFC, Greenbelt, MD 20771, USA ³ Universities Space Research Association ⁴ Faculty of Humanities and Social Sciences, Iwate University, Ueda 3-18-34, Morioka, Iwate 020-8550, Japan ⁵ Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan

Abstract
We report several important results obtained from recent Galactic X-ray survey observations, in particular ASCA Galactic center and plane surveys and our Chandra deep survey on the $(l,b) \approx (28\fdg5,0\fdg0)$ region. Strong hard X-ray diffuse components are observed from Galactic ridge, center and bulge, and they have both thermal and non-thermal spectral components. Dozens of discrete and extended sources have been discovered on the Galactic plane, which also indicate thermal and/or non-thermal X-ray energy spectra. They are often associated with radio sources and are considered to be SNR candidates. Most of the hard X-ray point sources in the outer part of the Galactic plane are considered to be background AGNs, while fraction of the Galactic hard X-ray sources (such as quiescent dwarf novae) increases toward the Galactic center. Most of the soft X-ray sources on the Galactic plane are presumably nearby active stars.

Key words:  Galactic Plane - X-rays - Galactic Diffuse Emission - Supernova Remnants - X-ray sources

Download full paper in PDF

Hard X-ray emission from low mass X-ray binaries    p.287

Tiziana Di Salvo^1,2 and Natale R. Robba²

¹ Astronomical Institute ``Anton Pannekoek," University of Amsterdam and Center for High-Energy Astrophysics, Kruislaan 403, NL 1098 SJ Amsterdam, the Netherlands; disalvo@science.uva.nl
² Dipartimento di Scienze Fisiche ed Astronomiche, Università di Palermo, via Archirafi n.36, 90123 Palermo, Italy

Abstract
In this paper we review our current knowledge of the hard X-ray emission properties of old accreting neutron stars in low mass X-ray binaries, with particular attention to recent results obtained for the brightest sources of this class, the so-called Z sources. While less luminous low mass X-ray binaries often show quite hard spectra, sometimes extending up to energies $\ga 100$ keV, the spectra of Z sources are always very soft, dominated by thermal components with characteristic temperatures $\sim 3-6$ keV. However, recent broad band observations revealed the presence of a weak hard (power-law) component that is sometimes present in the spectra of these sources. These observations have strengthened the analogies between the spectral behavior of low mass X-ray binaries hosting neutron stars and binary systems containing black hole candidates. The physical parameters regulating the presence of this hard component are unknown yet. The first parameter may be the mass accretion rate, as indicated by the general anticorrelation between the fraction luminosity in hard X-rays and mass accretion rate apparent over different sources spanning a large range of luminosities as well as individual sources undergoing state changes. However, a second, yet unknown, parameter is probably needed to explain all the phenomenology. The broad high energy coverage and good sensitivity of the INTEGRAL mission can represent an important step forward in the understanding of the origin and properties of high energy components in accreting X-ray binaries.

Key words:   accretion, accretion disks -- stars: neutron -- X-rays: stars -- X-rays: binaries -- X-rays: general

Download full paper in PDF

The ASCA and Chandra Observations of the Galactic center    p.297

Katsuji Koyama¹, Atsushi Senda¹, Hiroshi Murakami², and Yoshitomo Maeda²

¹ Cosmic ray group, Department of Physics, Kyoto University, Sakyo, Kyoto, 606-8502, Japan; koyama@cr.scphys.kyoto-u.ac.jp
² Institute of Space and Astronautical Science, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan

Abstract
This paper reports the new results of the high energy activity found with the X-ray observations of the Galactic center (GC). The Ginga satellite discovered the largely extended hot plasma around the GC, suggesting a violent activity of the GC within 10⁵ year. ASCA found strong 6.4 keV line emissions from the molecular clouds near the GC, which is well explained by the fluorescent caused by strong X-ray irradiations from Sgr A^* of $\sim$ 100-300 years ago. Recent Chandra observations on the GC have confirmed these previous results and moreover, with its unprecedented spatial resolution, have resolved a number of non-thermal/6.4-keV X-ray filaments and jet-like structures possibly caused by Sgr A^*. We infer that these complexities in morphology and spectrum of the GC X-ray are due to coupled actions of recent supernova explosions, a super massive black hole and giant molecular clouds.

Key words:  Galaxy: center -- ISM: clouds -- X-rays: ISM

Download full paper in PDF

The Galactic Center as a Dark Matter $\gamma$-Ray Source    p.305

Alessandro Cesarini

INFN Roma2 and University of Roma ``Tor Vergata", Via della Ricerca Scientifica, 1, 00133 Rome, Italy; alessandro.cesarini@roma2.infn.it

Abstract
The EGRET telescope has found evidence for a $\gamma$-ray source at the Galactic center (GC). We investigate whether the spectral features of this source are compatible with the $\gamma$-ray flux induced by pair annihilations of dark matter weakly interacting massive particles (WIMPs). We show that the discrimination between this interpretation and other viable explanations will be possible with GLAST, the next major $\gamma$-ray telescope in space. On the other hand, we also show that if the data will point to an alternative explanation, there will still be the possibility for GLAST to single out a weaker dark matter source at the GC. The talk is entirely based on Cesarini et al. (19 ).

Key words:  gamma-rays -- dark matter -- supersymmetry -- Galactic center

Download full paper in PDF

On the optical counterpart of SAX J1808.4-3658 during quiescence: evidence for an active radio pulsar?    p.311

L. Burderi¹, T. Di Salvo², F. D'Antona¹, V. Testa¹, R. Iaria², G. Lavagetto², and N. R. Robba²

¹ Osservatorio Astronomico di Roma, via Frascati 33, 00040 Monteporzio Catone (Roma), Italy
² Dipartimento di Scienze Fisiche ed Astronomiche, Università di Palermo, via Archirafi n.36, 90123 Palermo, Italy; burderi@mporzio.astro.it

Abstract
The optical counterpart of the binary millisecond X-ray pulsar SAX J1808.4-3658 during quiescence was detected at V =21.5 mag, inconsistent with intrinsic emission from the faint companion star. We propose that the optical emission from this system during quiescence is due to the reprocessing by the companion star and a remnant accretion disk of the rotational energy released by the fast spinning neutron star, switched on, as magneto-dipole rotator (radio pulsar), during quiescence. In this scenario the companion behaves as a bolometer, reprocessing in optical the intercepted fraction of the power emitted by the pulsar. This reprocessed fraction depends only on known binary parameters. Thus the blackbody temperature of the companion can be predicted and compared with the observations. Our computations indicate that the observed optical magnitudes are fully consistent with this hypothesis. In this case the observed optical luminosity may be the first evidence that a radio pulsar is active in this system during quiescence.

Key words:   accretion, accretion disks - stars: individual: -- stars: neutron -- X-rays: stars -- X-rays: binaries -- X-rays: general

Download full paper in PDF

Understanding Pulsar Wind Nebulae: recent progress and open questions    p.316

Elena Amato

INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5, I-50125, Firenze, Italy; amato@arcetri.astro.it

Abstract
I present a short review of our current understanding of Pulsar Wind Nebulae (PWNe). I will try to highlight the recent progress made towards solving some long standing puzzles concerning the physics of these objects. The main focus will be on the problems related to the dissipation of the pulsar wind energy and to the acceleration of the relativistic particles that produce the non-thermal nebular emission. The kind of observations that will possibly provide, in the near future, important information concerning some of the open problems will also be discussed, together with some possible lines of development of future theoretical work.

Key words:  acceleration of particles - MHD - neutrinos - shock waves - stars: winds, outflows - supernova remnants

Download full paper in PDF

High Resolution X-ray Observations of Supernova Remnants    p.329

F. Bocchino

INAF-Osservatorio Astronomico ``Giuseppe S. Vaiana", Palermo Italy; bocchino@astropa.unipa.it

Abstract
The study of supernova remnants (SNRs) in the X-ray band is greatly benefiting from the availability of the large collecting area, high spatial resolution and good spectral resolution of instruments aboard XMM-Newton and Chandra satellites. The possibility of performing accurate spatially resolved spectra analysis is of course of great importance for the study of extended sources. In this review, I will briefly present a few SNR topics which, on my opinion, have greatly advanced thanks to the current generation X-ray observatories, with the aim to give a general idea on the quality of the data and the kind of research that people are doing with them.

Key words:  supernova remnants -- X-rays: supernova remnants

Download full paper in PDF

Multifrequency study of the very slow nova V723 Cas    p.341

D. Chochol¹, T. Pribulla¹, and A.A. Vittone²

¹ Astronomical Institute of the Slovak Academy of Sciences, 05960 Tatranská Lomnica, Slovak Republic; chochol@ta3.sk
² Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy;

Abstract
Multifrequency behaviour of the very slow nova V723 Cas is reviewed. The long-term photometry of the object revealed the orbital period 0.693265 days of the binary, quasi-periodic oscillations in the envelope of the outbursted white dwarf and 182 days periodicity of activity due to the mass transfer bursts from the red to the white dwarf probably caused by a periastron passage of the third body. The photometry at the maximum of brightness was used to calculate the velocity $v = 210 {\rm km s}^{-1}$ of ejection of an expanding supergiant photosphere -- main inner envelope of the nova. The emission line profiles in nebular stage show multiple peaks formed in an expanding equatorial ring and polar blobs of this envelope. The HeI line profile and radio observations suggest the existence of the outer envelope, shaped and accelerated by the spherical and polar winds, detected as absorption components of the HI and HeI P Cygni type line profiles. Radio observations allowed to determine ejected mass 2.5 x 10^-4M$_{\odot}$ and confirmed the clumpy structure of the ejecta.

Key words:   stars: novae - cataclysmic variables - circumstellar matter: individual: V723 Cas

Download full paper in PDF

ETA CARINAE -- an evolved triple-star system?    p.349

Wolfgang Kundt¹ and Christoph Hillemanns²

¹ Institut für Astrophysik der Universität, Auf dem Hügel 71, D-53121 Bonn
² Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn; now employed at Detecon International GmbH; wkundt@astro.uni-bonn.de

Abstract
From the wealth of data on the source $\eta$ Carinae it is concluded that it consists of two moderately massive (ordinary) stars plus a neutron star, the latter in close orbit around the secondary. As an extreme case among high-mass stars, $\eta$ Car may teach us that stellar masses do not exceed 60$M_{\odot}$. Several of $\eta$ Car's peculiar properties are due to its three interacting wind zones. Its transient super-Eddington outputs -- during the years 1843 and 1887 -- are blamed on the assemblance of a heavy accretion disk around the neutron star (near peri-astron), and the disk's occasional discharging towards it.

Key words:   $\eta$ Carinae - stars: most massive - super-Eddington sources - triple-star system

Download full paper in PDF

Short-period Active Binaries -- Retrospect and Prospects    p.361

T. Pribulla¹, D. Chochol¹ and A.A. Vittone²

¹ Astronomical Institute of the Slovak Academy of Sciences, 05960 Tatranská Lomnica, Slovak Republic; pribulla@ta3.sk
² Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy

Abstract
The most important characteristics and multi-frequency behaviour of the active RS CVn binaries are reviewed. New long-term photometric and spectroscopic observations of several short-period active RS CVn binaries are presented. The results for RT And, XY UMa and preliminary analysis of SV Cam and ER Vul are given. New prospects for research in the field are outlined.

Key words:  techniques: photometric -- stars: variables: RS CVn binaries -- stars: individual: RT And, SV Cam, CG Cyg, XY UMa, ER Vul

Download full paper in PDF

A Preliminary BeppoSAX Study of the (Bright) Atoll Source GX 9+1    p.367

R. Iaria¹, G. Augello¹, T. Di Salvo^1,2, N. R. Robba¹, L. Burderi³ and L. Stella³

¹ Dipartimento di Scienze Fisiche ed Astronomiche, Università di Palermo, Via Archirafi 36, 90123 Palermo, Italy; iaria@gifco.fisica.unipa.it
² Astronomical Institute ``Anton Pannekoek'', University of Amsterdam and Center for High-Energy Astrophysics, Kruislaan 403, NL 1098 SJ Amsterdam, the Netherlands
³ Osservatorio Astronomico di Roma, Via Frascati 33, 00040 Monteporzio Catone (Roma), Italy

Abstract
We report the preliminary results of a 350 ks BeppoSAX observation of the bright atoll source ${\rm GX} 9+1$. In the field of view of the MECS instrument we discovered a X-ray pulsar, designated SAX J1802.7-2017, at an angular distance from GX 9+1 of $\sim 22^{\prime}$. Since the X-ray emission of SAX J1802.7-2017 contaminates the energy spectrum above 10 keV we studied the energy spectrum of ${\rm GX} 9+1$ in the energy band 0.1-10keV. We selected four regions in the color-color diagram and extracted one spectrum from each region. A bump below 1keV is present in the spectra using a model composed by a Comptonized component absorbed by neutral matter having an equivalent hydrogen column of 1.5 x 10²²cm^-2. The bump disappears adding an overabundance of iron and nickel of 7 and 70 with respect to the solar iron abundance and to the solar nickel abundance, moreover the equivalent hydrogen column becames 0.5 x 10²² cm^-2 suggesting a possible distance to the source of 4.5 kpc, implying a luminosity of 4 x 10³⁷ergs^-1 and that the bright atoll source ${\rm GX} 9+1$ is not bright but it is a typical atoll source.

Key words:  accretion discs - stars: individual: GX 9+1 -- stars: neutron stars -- X-ray: stars -- X-ray: spectrum -- X-ray: general

Download full paper in PDF

Jets in Astrophysics: a Review    p.373

J.H. Beall^1,2,3

¹ E. O. Hulburt Center for Space Research, Naval Research Laboratory, Washington, DC 20375; beall@sjca.edu
² Center for Earth Observing and Space Research, School for Computational Sciences, George Mason University, Fairfax, VA 22030
³ St. John's College, Annapolis, MD 21404, USA

Abstract
We discuss observations used to infer the presence of accretion disks in astrophysical sources and the disks' association with evidence for astrophysical jets. We highlight some important results from past and current literature that show parallels between the temporal behavior of an active galaxy (NGC 5128) and a galactic microquasar (GRS 1915+105). In addition, we note the remarkable observations of the time history of SCO X-1 from VLBI data at radio frequencies.

Key words:  accretion; accretion disks; stars:outflows acceleration of particles; black hole physics; radiation mechanisms

Download full paper in PDF

Multifrequency Radiation of Extragalactic Large-Scale Jets    p.383

Lukasz Stawarz Obserwatorium Astronomiczne, Uniwersytet Jagiellonski, ul. Orla 171, 30-244 Kraków, Poland; stawarz@oa.uj.edu.pl

Abstract
Large-scale extragalactic jets, observed to extend from a few to a few hundred kiloparsecs from active galactic nuclei, are now studied over many decades in frequency of electromagnetic spectrum, from radio until (possibly) TeV $\gamma$ rays. For hundreds of known radio jets, only about 30 are observed at optical frequencies. Most of them are relatively short and faint, with only a few exceptions, like 3C 273 or M 87, allowing for detailed spectroscopic and morphological studies. Somewhat surprisingly, the large-scale jets can be very prominent in X-rays. Up to now, about 30 jets were detected within the 1 - 10keV energy range, although the nature of this emission is still under debate. In general, both optical and X-ray jet observations present serious problems for standard radiation models for the considered objects. Recent TeV observations of M 87 suggest the possibility of generating large photon fluxes at these high energies by its extended jet. In this paper we summarize information about multiwavelength emission of the large-scale jets, and we point out several modifications of the standard jet radiation models (connected with relativistic bulk velocities, jet radial stratification and particle energization all the way along the jet), which can possibly explain some of the mentioned puzzling observations. We also comment on $\gamma$-ray emission of the discussed objects.

Key words:   acceleration of particles -- radiation mechanisms: non-thermal -- galaxies: jets

Download full paper in PDF

Understanding the Chandra Detected X-ray Emission of the Knots and Hot Spots of Powerful Extragalactic Jets    p.404

Markos Georganopoulos    

NASA/GSFC, Laboratory for High Energy Astrophysics, Greenbelt, MD 20771, USA; markos@milkyway.gsfc.nasa.gov

Abstract
I present here a short personal view of our understanding of the Chandra detected knots and hot spots of powerful Fanaroff Rilley (FR) II radio galaxies and quasars in the context of leptonic models. Observations of the knots and hot spots strongly suggest that the jets in these powerful sources retain their relativistic velocities at large scales, all the way to the hot spots. The emission mechanism suggested for the knots of quasars and FR II radio galaxies is external Compton (EC) off the cosmic microwave backgounrd (CMB) from a relativistic flow, while for the hotspots Upstream Compton (UC) scattering from a decelerating relativistic flow.

Key words:  radiation mechanisms: non-thermal - galaxies: quasars

Download full paper in PDF

Accretion Disk Spectra of the Ultra-luminous X-ray Sources in Nearby Spiral Galaxies and Galactic Superluminal Jet Sources    p.415

Ken Ebisawa^1,2,3, Piotr Zycki⁴, Aya Kubota⁵, Tsunefumi Mizuno⁶, and Ken-ya Watarai⁷

¹ INTEGRAL Science Data Centre, chemin d'Écogia 16, Versoix, 1290 Switzerland; ebisawa@obs.unige.ch
² code 662, NASA/GSFC, Greenbelt, MD 20771, USA
³ Universities Space Research Association
⁴ N. Copernicus Astronomical Center, Bartycka 18, 00-716 Warsaw, Poland
⁵ Institute of Space and Astronautical Science, 3-1-1 Yoshinodai, Sagamihara, Kanagawa, 229-8510 Japan
⁶ Stanford Linear Accelerator Center, 2575 Sand Hill Road, M/S 43A, Menlo Park, CA 94025, USA
⁷ Yukawa Institute for Theoretical Physics, Kyoto University, Sakyo-ku, Kyoto, 606-8502 Japan

Abstract
Ultra-luminous Compact X-ray Sources (ULXs) in nearby spiral galaxies and Galactic superluminal jet sources share the common spectral characteristic that they have unusually high disk temperatures which cannot be explained in the framework of the standard optically thick accretion disk in the Schwarzschild metric. On the other hand, the standard accretion disk around the Kerr black hole might explain the observed high disk temperature, as the inner radius of the Kerr disk gets smaller and the disk temperature can be consequently higher. However, we point out that the observable Kerr disk spectra becomes significantly harder than Schwarzschild disk spectra only when the disk is highly inclined. This is because the emission from the innermost part of the accretion disk is Doppler-boosted for an edge-on Kerr disk, while hardly seen for a face-on disk. The Galactic superluminal jet sources are known to be highly inclined systems, thus their energy spectra may be explained with the standard Kerr disk with known black hole masses. For ULXs, on the other hand, the standard Kerr disk model seems implausible, since it is highly unlikely that their accretion disks are preferentially inclined, and, if edge-on Kerr disk model is applied, the black hole mass becomes unreasonably large ( $\geq300 M_\odot$). Instead, the slim disk (advection dominated optically thick disk) model is likely to explain the observed super-Eddington luminosities, hard energy spectra, and spectral variations of ULXs. We suggest that ULXs are accreting black holes with a few tens of solar mass, which is not unexpected from the standard stellar evolution scenario, and that their X-ray emission is from the slim disk shining at super-Eddington luminosities.

Key words:  superluminal jet sources: ultra-luminous X-ray sources - accretion disks, slim disks - Schwarzschild black holes, Kerr black holes

Download full paper in PDF

Cygnus X-3 in the INTEGRAL era ^*        p.425

L. Hjalmarsdotter¹, D. Hannikainen¹, O. Vilhu^1,2, A. A. Zdziarski³, S. Trushkin⁴, M. McCollough⁵, G. Pooley⁶, P. Hakala¹, and A. Paizis^2,7

¹ Observatory, P.O. Box 14, FIN-00014 Helsinki, Finland; nea@astro.helsinki.fi
² INTEGRAL Science Data Center, Chemin d'Écogia 16, CH-1290 Versoix, Switzerland
³ Centrum Astronomiczne im. M. Kopernika, Bartycka 18, 00-716 Warszawa, Poland
⁴ RATAN SAO, RAS, Nizhnij Arkhyz, Karachaevo-Cherkassia 369167, Russia
⁵ SAO, 60 Garden Street, MS 67, Cambridge, MA 02138-1516, USA
⁶ Astrophysics Group, Cavendish Lab. Madingley Road, Cambridge CB3 0HE UK
⁷ CNR-IASF, Sezione di Milano, Via Bassini 15, 20133 Milano, Italy

Abstract
Active throughout the entire electromagnetic spectrum, CygX-3 provides an excellent target for studying the multiwavelength behaviour of an accreting binary system. In this paper we present the results of the first observations of the source in 2002 December, together with simultaneous /PCA-HEXTE observations and radio observations by Ryle and RATAN radio telescopes. The X-ray spectra were fitted with a thermal Comptonization model. The radio spectra from RATAN have the shape of a highly self-absorbed synchrotron spectrum with indications of a minor ejection event coinciding with the peak of an X-ray flare on the days before the observations.

Key words:  gamma rays: observations -- stars: individual: Cyg X-3 -- X-rays: binaries -- X-rays: general -- X-rays: stars

Download full paper in PDF

Cosmic Gamma-Ray Bursts: The Big Picture    p.431

Kevin Hurley UC Berkeley, Space Sciences Laboratory, Berkeley, CA 94720-7450, U.S.A.; khurley@sunspot.ssl.berkeley.edu

Abstract
The observational properties (time histories, energy spectra, and spatial distribution) of cosmic gamma-ray bursts and their multi-wavelength afterglows are reviewed. Although one class of burst (the long bursts) can be attributed to the collapse of massive stars, the origin of another class (the short bursts) is still mysterious. This is only one of several questions which remains to be answered. However, despite our incomplete understanding, it is clear that this phenomenon has finally entered the mainstream of astrophysical research, and has numerous applications to other studies.

Key words:  gamma-rays: bursts

Download full paper in PDF

Gamma Ray Bursts in the Afterglow Era    p.439

Filippo Frontera 

University of Ferrara, Physics Department, Via Paradiso, 12, 44100 Ferrara, Italy; frontera@fe.infn.it
Istituto Astrofisica Spaziale e Fisica Cosmica, INAF, Via P. Gobetti, 101, 44129 Bologna, Italy

Abstract
In this review paper I will summarize some of the relevant results obtained with the Italian satellite on the prompt and afterglow emission of Gamma Ray Bursts. I will also discuss the most relevant open issues on these events.

Key words:  gamma-rays: bursts - gamma-rays: observations

Download full paper in PDF

Gamma-Ray Bursts and Cosmology    p.449

G. Barbiellini and F. Longo

Department of Physics, University of Trieste and INFN, sezione di Trieste, Italy; francesco.longo@ts.infn.it

Abstract
A general review of the study of Gamma Ray Bursts (GRB) in the cosmological context is provided. The GRB, which distance was unknown since a few years ago, are now among the different astrophysical sources the most promising tool for doing cosmology.

Key words:  gamma-rays: bursts - cosmology: observations

Download full paper in PDF

Intrinsic spectra and energetics of cosmological Gamma-Ray Bursts    p.455

L. Amati

Istituto di Astrofisica Spaziale e Fisica Cosmica - Sez. Bologna, CNR, via P. Gobetti 101, I-40129 Bologna, Italy; amati@bo.iasf.cnr.it

Abstract
We extend a previous work on the intrinsic spectral properties and energetics of GRBs with known redshift based on 12 BeppoSAX events by including in the sample a total of 10 more events detected either by BATSE, BeppoSAX or HETE-2. An indication of a trend of the total isotropic equivalent radiated energy, $E_{\rm rad}$, with redshift is found and, remarkably, the previously found relationship between the peak energy of the rest-frame $\nu F \nu$ spectrum, $E_{\rm p}^{\rm rest}$ and $E_{\rm rad}$ is confirmed and its significance increased. The implications of these results are briefly discussed in the framework of standard models for the prompt emission of GRBs.

Key words:  gamma-rays: observations - gamma-rays: bursts

Download full paper in PDF

Multiwavelength afterglows of Gamma-Ray Bursts    p.461

Elena Pian^1,2 and Jens Hjorth³

¹ INAF, Astronomical Observatory of Trieste, Via G.B. Tiepolo 11, I-34131 Trieste, Italy; pian@ts.astro.it
² CNR-IASF, Via. P. Gobetti 101, I-40129 Bologna, Italy;
³ Niels Bohr Institute, Astronomical Observatory, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø, Denmark

Abstract
Our knowledge of Gamma-Ray Burst (GRB) progenitors is based on three cases at relatively low redshift (between 0.01 and 0.2) in which the association with a supernova (SN) has been firmly established. In a number of higher redshift GRBs the presence of a SN has been suggested, although the properties of the SN could not be precisely determined. However, the study of several tens of multiwavelength afterglows has now provided evidence that GRBs are associated with star formation. The observational results which point to this connection are reviewed, and the high energy properties of afterglows and SNe are compared.

Key words:  Gamma-ray bursts -- Supernovae

Download full paper in PDF

GRBs-SN and SGR-X-Pulsar as blazing Jets    p.472

Daniele Fargion

Physics Department, University of Rome P.le A. Moro, 2, 00185 ROME, ITALY; daniele.fargion@roma1.infn.it

Abstract
Old and recent puzzles of GRBs and SGRs find a solution with a model based on the fast blazing of very collimated thin gamma Jets. Damped oscillating afterglows in GRB 030329 find a natural explanation assuming a very thin Jet - $\frac{\Delta\Omega}{\Omega}\leq 10^{-8}$ - whose persistent activity and different angle of view maybe combined at once with the Supernovæ power and the apparent huge GRBs output: $\dot{E}_{\rm GRBs} \simeq$ $\dot{E}_{\rm SN}$$\frac{\Omega}{\Delta\Omega}$. This leads to a better understanding of the remarkable GRB-Supernovæ connection discovered in the GRB 980425/SN 1998bw and in the most recent GRB 030329/SN 2003dh events. The same thin beaming offer an understanding of the apparent SGR-Pulsar power connection: $\dot{E}_{\rm SGRs} \simeq$ $\dot{E}_{\rm Xpuls}$$\frac{\Omega}{\Delta\Omega}$. A thin collimated precessing Gamma Jet model for both GRBs and SGRs, at their different scaled luminosity ( 10³⁸-10⁴⁴ erg s^-1), explains the existence of few identical energy spectra and time evolution of these sources leading to a unified model. Their similarity with the huge precessing Jets in AGN, QSRs and Radio-Galaxies inspires this smaller scale SGR-GRB model. The spinning-precessing Jet explains the rare ($\approx 6\%$) mysterious X-Ray precursors in GRBs and SGRs events. Any large Gamma Jet off-axis beaming to the observer might lead to the X-Flash events without any GRB signals, as the most recent XRF 030723. Its possible re-brightening would confirm the evidence of the variable pointing of the jet in or off line towards the observer. Indeed a multi-precessing Jet at peak activity in all bands may explain the puzzling X or optical re-brightening bumps found in the GRB 021004, GRB 030329 and the SGR 1900+ 14 on 27 August 1998 and once again on the 18 April 2001. Rarest micro-quasars neutron star in our galaxy as SS433, and Herbig Haro objects and Cir-X-1 describe these thin precessing Jet imprints in the spectacular shapes of their relic nebulae.

Download full paper in PDF

News on multifrequency behaviour of GRBs: polarized emission and optical flashes    p.483

Nicola Masetti

Istituto di Astrofisica Spaziale e Fisica Cosmica, Sezione di Bologna, CNR, via Gobetti, 101 I-40129 Bologna (Italy); masetti@bo.iasf.cnr.it

Abstract
In this presentation the main advances occurred in the past years concerning the observational features of Gamma-Ray Burst (GRB) prompt event and afterglow polarization in the optical, as well as in other bands, are reviewed. Also, the observed cases of an `optical flash' simultaneous with the GRB itself are presented, along with their theoretical interpretation and the description of present and future observational fast-response techniques to chase this emission.

Key words:  gamma rays: bursts -- techniques: polarimetric -- techniques: photometric

Download full paper in PDF

Physical Limits of Different Models of Cosmic Gamma-Ray Bursts    p.489

Gennady S. Bisnovatyi-Kogan^1,2

¹ Space Research Inst. Rus. Acad. Sci, Profsoyuznaya 84/32, Moscow 117997, Russia; gkogan@mx.iki.rssi.ru
² Joint Institute of Nuclear Researches, Dubna, Russia

Abstract
The present common view about GRB origin is related to cosmology, what is based on statistical analysis, and on measurements of the redshifts in the GRB optical afterglows of long GRB. No correlation is found between redshifts, GRB spectrum, and total GRB fluence. Comparison of KONUS and BATSE data about statistics and hard X-ray lines is done, and some differences are noted. Hard gamma-ray afterglows, prompt optical spectra, hard X-ray lines measurements could be important for farther insight into GRB origin. Possible possible connection of short GRB with soft gamma repeaters is discussed.

Key words:  gamma-rays, X-rays, transients

Download full paper in PDF

Gamma-Ray Bursts: explained my way    p.501

Wolfgang Kundt

Institut für Astrophysik der Universität, Auf dem Hügel 71, D-53121 Bonn, Germany; wkundt@astro.uni-bonn.de

Abstract
Ordered historically, I shall update my earlier conviction that a consistent interpretation of all the non-terrestrial gamma-ray bursts can be obtained in terms of nearby Galactic neutron stars, at distances d within 10 $\lesssim d$/pc $\lesssim$ 500.

Key words:  gamma-ray bursts - afterglows - host galaxies - neutron stars: accretion

Download full paper in PDF

The Swift Mission and the Robotic Telescope REM    p.507

Guido Chincarini^1,2 on behalf of the Swift and REM Team

Università degli Studi di Milano Bicocca; guido@merate.mi.astro.it
Osservatorio Astronomico di Brera

Abstract
The Swift satellite and the REM telescope projects are devoted to the study of Gamma-Ray bursts. Both missions are mainly designed to investigate on the prompt GRB emission. In the following, we give a brief outline of GRB science and describe the main technical capabilities of Swift and REM.

Key words:  gamma rays: bursts - space vehicles: instruments - telescopes

Download full paper in PDF

The Gamma-Ray Imaging Detector AGILE: Scientific Goals and Instrument Performance    p.517

Carlotta Pittori on behalf of the AGILE Team

Università di Roma ``Tor Vergata" and INFN Sez. di Roma 2, Via della Ricerca Scientifica 1, 00133 Roma, Italy; carlotta.pittori@roma2.infn.it

Abstract
AGILE is an ASI Small Scientific Mission dedicated to gamma-ray astrophysics, which will detect and image photons in the 30-50and in the 10-40energy ranges. It is planned to be operational during the second half of 2005 and it will be the only mission entirely dedicated to high energy astrophysics above 30during the period 2005-2007. We discuss the expected performance of the AGILE space detector, which scientific program emphasizes a quick response to gamma-ray transients and multiwavelength studies of gamma-ray sources.

Key words:  gamma rays: observations - gamma rays: theory - instrumentation: detectors

Download full paper in PDF

The Gamma Large Area Space Telescope: GLAST    p.523

Aldo Morselli (on the behalf of the GLAST Collaboration)

INFN Roma2 and University of Roma ``Tor Vergata", Via della Ricerca Scientifica 00133 Rome, Italy; aldo.morselli@roma2.infn.it

Abstract
The GLAST mission is a high-energy gamma-ray observatory designed for making observations of celestial gamma-ray sources in the energy band extending from 20 MeV to 300 GeV. Our understanding of the Universe has experienced a revolution in the last several years with breakthrough observations of many new phenomena that have changed our view of the high energy Universe and raised many new questions. The GLAST mission stands poised to open enormous opportunities for answering these questions and advancing knowledge in astrophysics and particle physics.

Key words:  gamma-rays -- dark matter -- gamma-rays experiment

Download full paper in PDF

The MAGIC telescope for gamma-ray astronomy above 30 GeV    p.531

A. Moralejo¹, C. Baixeras², D. Bastieri¹, W. Bednarek¹³, and C. Bigongiari¹, A. Biland⁴, O. Blanch⁵, R. Böck⁶, T. Bretz⁷, A. Chilingarian⁸, J. A. Coarasa⁶, E. Colombo⁷, S. Commichau⁴, J. L. Contreras⁹, J. Cortina⁵, A. De Angelis³, R. De los Reyes⁹, B. De Lotto³, C. Domingo², E. Domingo⁵, D. Dorner⁷, D. Ferenc¹¹, E. Fernández⁵, J. Flix⁵, V. Fonseca⁹, L. Font², N. Galante¹², M. Gaug⁵, M. Garczarczyk⁶, J. Gebauer⁶, R. Giannitrapani³, M. Giller¹³, F. Goebel⁶, T. Hengstebeck¹⁴, P. Jacon¹³, O. C. de Jager¹⁰, O. Kalekin^14,16, M. Kestel⁷, K-S. Kim⁴, T. Kneiske⁷, M. Laatiaoui⁶ A. Laille¹¹, E. Lindfors¹⁵, F. Longo³, M. López⁹, J. López⁵, E. Lorenz⁶, F. Lucarelli⁹, K. Mannheim⁷, M. Mariotti¹, M. Martínez⁵, K. Mase⁶, M. Merck⁷, M. Meucci¹², R. Mirzoyan⁶, S. Mizobuchi⁶, A. Moralejo¹, E. Oña-Wilhelmi^9,10, R. Orduña², D. Paneque⁶, R. Paoletti¹², M. Pasanen¹⁵, D. Pascoli¹, F. Pauss⁴, N. Pavel¹⁴, R. Pegna¹², L. Peruzzo¹, A. Piccioli¹², M. Pin³, A. Robert², A. Saggion¹, A. Sánchez², P. Sartori¹, V. Scalzotto¹, K. Shinozaki⁶, A. Sillanpaa¹⁵, D. Sobczynska¹³, A. Stamerra¹³, L. S. Stark⁴, A. Stepanian¹⁶, R. Stiehler¹⁴, L. Takalo¹⁵, M. Teshima⁶, N. Tonello⁶, A. Torres², N. Turini¹², G. Viertel⁴, V. Vitale⁶, S. Volkov¹⁴, R. Wagner⁶, T. Wibig¹³, and W. Wittek⁶

¹ Dipartimento di Fisica ``Galileo Galilei'', Università di Padova e Istituto Nazionale di Fisica Nucleare, Sezione di Padova. Via Marzolo, 8, 35131 Padova, Italia.
² Universitat Autònoma de Barcelona
³ Dipartimento di Fisica dell'Università di Udine e INFN Udine/Trieste
⁴ Institute for Particle Physics, Swiss Federal Institute of Technology (ETH) Zurich
⁵ Institut de Fisica d'Altes Energies, Barcelona
⁶ Max-Planck-Institut für Physik, München
⁷ Universität Würzburg
⁸ Yerevan Physics Institute, Cosmic Ray Division, Yerevan
⁹ Facultad de Ciencias Físicas, Universidad Complutense, Madrid
¹⁰ Space Research Unit, Potchefstroom University
¹¹ University of California, Davis
¹² Dipartimento di Fisica, Università di Siena & INFN sez. Pisa
¹³ Division of Experimental Physics, University of Lodz
¹⁴ Fachbereich Physik, Universität-GH Siegen
¹⁵ Tuorla Observatory, Pikkiö
¹⁶ Crimean Astrophysical Observatory; moralejo@pd.infn.it

Abstract
The MAGIC telescope, presently at its commissioning phase, will become fully operative by the end of 2003. Placed at the Roque de los Muchachos Observatory (ORM) on the island of La Palma, MAGIC is the largest among new generation ground-based gamma ray telescopes, and will reach an energy threshold as low as 30 GeV. The range of the electromagnetic spectrum between 10 and 250 GeV remains to date mostly unexplored. Observations in this energy region are expected to provide key data for the understanding of a wide variety of astrophysical phenomena belonging to the so-called ``non thermal Universe'', like the processes in the nuclei of active galaxies, the radiation mechanisms of pulsars and supernova remnants, and the enigmatic gamma-ray bursts. An overview of the telescope and its physics goals is presented.

Key words:  instrumentation: detectors - techniques: miscellaneous

Download full paper in PDF

Multiwavelengths Observations with the MAGIC Telescope    p.539

T. M. Kneiske and K. Mannheim

Lehrstuhl fuer Astronomie, Universitaet Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany; kneiske@astro.uni-wuerzburg.de

Abstract
This paper reports the observability of distant gamma-sources using groundbased imaging air-Cherenkov telescopes with low energy thresholds like the MAGIC telescope. In particular we focus on extragalactic sources at low and high redshift which are emitting gamma photons up to very high energies. AGN for example are one of the most promising candidates for multiwavelength observations. The presented calculation is easy to apply on any extragalctic source emitting gamma-rays in the GeV/TeV energy range e.g. gamma-ray bursts (GRB). The data taken with a gamma-telescope (groundbased or airborne), have to be corrected for extragalactic absorption due to the metagalactic radiation field (MRF). The multiwavelength compain of the MAGIC telescope is breavely discribed.

Key words:  AGN: Blazars Spectra - Metagalactic Radiation Fields: UV-IR - Imaging Cherenkov Telescopes: MAGIC

Download full paper in PDF

TUNGUSKA 1908    p.545

Wolfgang Kundt

Institut für Astrophysik der Universität, Auf dem Hügel 71, D-53121 Bonn; wkundt@astro.uni-bonn.de

Abstract
In the literature, the Siberian forest destruction of 30 June 1908 - north of the Stony Tunguska river - is almost unanimously explained by the impact of some huge meteorite even though no trace of it has ever been found, and even though some 20 facts argue in favour of a tectonic event. An in-depth discussion plus a comparison with smaller, more recent events suggest that we deal with the - first recorded - present-day formation of a kimberlite.

Key words:  Tunguska - catastrophe - outburst - kimberlite - impact - NEOs

Download full paper in PDF

Concluding Remarks I    p.555

Gennady S. Bisnovatyi-Kogan^1,2

¹ Space Research Inst. Rus. Acad. Sci, Profsoyuznaya 84/32, Moscow 117997, Russia; gkogan@mx.iki.rssi.ru
² Joint Institute of Nuclear Researches, Dubna, Russia

Abstract
Some interesting topics presented in the Workshop are discussed.

Download full paper in PDF

Concluding Remarks II    p.558

Janusz Ziókowski

Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warsaw, Poland; jz@camk.edu.pl

Abstract
The program of the conference was prepared so well (thanks to the organizers) that we got complete and competent reviews in all important fields of high energy cosmic sources. It is not easy to select just a few topics and any choice will be, necessarily, arbitrary. I decided to make brief comments on cosmology, on gamma ray bursts and on X-ray flashes. My personal nomination for the hit of the conference goes this year to the ``Rosetta stone" of gamma ray bursts (term used by Elena Pian): GRB030329 = SN 2003dh

Download full paper in PDF

Concluding Address    p.561

Franco Giovannelli

Istituto di Astrofisica Spaziale e Fisica Cosmica, CNR - Sezione di Roma
Area di Ricerca CNR di Roma-2, Via del Fosso del Cavaliere, 100, I 00133 Roma, Italy; franco@rm.iasf.cnr.it

Abstract
Before to conclude officially this workshop - far from me the idea to attempt some concluding remarks already well done by Guennadi Bisnovatyi-Kogan and Janusz Ziokowski - I would like to comment few highlights coming out from our fruitful week of discussions on multifrequency astrophysics, without any pretension of completeness.

Key words:  Multifrequency Astrophysics

Download full paper in PDF

Chinese Journal Astronomy Astrophysics  Special Issue for Frascati Workshop 2003 

The Chinese Journal of Astronomy and Astrophysics (ChJAA, ISSN 1009-9271) 

is a bimonthly English-language international journal that publishes original research papers in astronomy and astrophysics. It is the principal journal of the Chinese astronomical community. It was started in 2001 and is a continuation of Acta Astrophysica Sinica (from 1981, ISSN 0253-2379).


2001-2005 (C) ChJAA

This page created by Aiying Zhou, 2005-05-02.