The INTEGRAL mission
INTEGRAL, the International Gamma-Ray Astrophysics Laboratory, to be launched in 2001, is the second medium-size scientific mission (M2) of the ESA long term programme “Horizon 2000”. INTEGRAL addresses the fine spectroscopy and accurate positioning of celestial gamma-ray sources in the energy range 10 keV to 10 MeV. The observational requirements will be met by a payload utilising coded mask imaging in combination with detector pixel arrays (Imaging) and cooled Germanium detectors (Spectroscopy). INTEGRAL is an ESA led mission in collaboration with Russia and USA. Most of the observing time will be made available to the general scientific community.

title: Warm absorber energetics in broad-line radio galaxies
abstract: We review the soft X-ray properties of 3C 390.3, 3C 120, 3C 382 and 3C 445, the only broad-line radio galaxies (BLRGs) for which good quality gratings data are currently available. The XMM–Newton/Reflection Grating Spectrometer data of 3C 390.3 and 3C 120 were re-analysed searching for warm absorbers, already discovered in 3C 382 and 3C 445. We confirm the absence of ionized absorption features in 3C 120, but find signatures of outflowing gas (vout∼ 102 km s−1) in 3C 390.3. Its warm absorber (log ξ∼ 2 erg cm s−1, NH∼ 1020 cm−2), similar to that observed in 3C 382, is probably placed in the narrow-line regions. Its gas content is slower and less dense than the accretion disc wind discovered in 3C 445. Independently from the location of the warm gas, the outflowing masses () of BLRGs are significantly (but improbably) predominant with respect to the accretion masses (), suggesting a clumpy configuration of the warm absorber. However, even assuming overestimated values of , the kinetic luminosity of the outflow () is well below 1 per cent of the kinetic power of the jet (Pjet). Thus, the jet remains the major driver of the radio-loud active galactic nucleus (AGN) feedback at least on a parsec scale and beyond. The warm absorber parameters (NH, ξ) of BLRGs span a similar range of values to type 1 radio-quiet AGNs. However, when the mass outflow rate of BLRGs and Seyfert 1s is plotted as a function of the radio loudness, R = log [νLν(5 GHz)/L(2-10 keV)], the mass outflow rate seems to increase with radio power.

title: An XMM-Newton Survey of Ultra-Luminous Infrared Galaxies
abstract: We present preliminary results of XMM-Newton observations of 5 Ultra-luminous Infrared Galaxies (ULIRGs), part of a mini-survey program dedicated to 10 ULIRGs selected from the bright IRAS sample. For 3 of them (IRAS 20551-4250, IRAS 19254-7245 and Mkn 231) we find strong evidence for the presence of a hidden AGN, while for two others (IRAS 20110-4156 IRAS 22491-1808) the S/N ratio of the data does not allow us to be conclusive. In particular, we have detected a strong Fe-K line in the X-ray spectra of IRAS19254-7245, with an equivalent width (~2 keV) suggestive that most of the energy source in this object is due to a deeply buried AGN.

title: Variable X-ray absorption in the mini-BAL QSO PG 1126-041
abstract: X-ray studies of AGN with powerful nuclear winds are important to constrain the physics of the inner accretion/ejection flow around SMBH, and to understand the impact of such winds on the AGN environment.  Our main scientific goal is to constrain the properties of a va riable outflowing absorber that is thought to be launched nea r the SMBH of the mini-BAL QSO PG 1126-041 using a multi-epoch observational campaign performed with XMM-Newton.  We performed temporally resolved X-ray spectroscopy and simultaneous UV and X-ray photometry on the most complete set of observations and on the deepest X-ray exposure of a mini-BAL QSO to date.  We found complex X-ray spectral variability on time scales of both months and hours, best reproduced by means of variable massive ionized absorbers along the line of sight. As a consequence, the observed optical-to-X-ray spectral index is found to be variable with time. In the highest signal-to-noise observa tion we detected highly ionized X-ray absorbing material outflowing much faster (υX∼ 16 500 km s −1 ) than the UV absorbing one (υuv∼ 5 000 km s −1 ). This highly ionized absorber is found to be variable on very short (a few kiloseconds) time scales.  Our findings are qualitatively consistent with line driven a ccretion disk winds scenarios. Our observations have opened the time-resolved X-ray spectral analysis field for mini-BA L QSOs; only with future deep studies will we be able to map the dynamics of the inner flow and understand the physics of AGN winds and th eir impact on the environment.

title: First Results from a XMM-Newton Survey of a Distance-Limited (D<22 Mpc) Sample of Seyfert Galaxies: I- the Agns
abstract: We report here preliminary results from a survey of nearby Seyfert galaxies using the EPIC CCDs on board XMM-Newton. The total sample consists of 28 Seyfert galaxies, and constitute a well-defined, complete (B 0 deg.) hemisphere. The survey has been initiated in June, 2001, and we report here the results for the 6 objects analyzed so far, namely: NGC3185, NGC3486, NGC3941, NGC4138, NGC4565, and NGC5033. The main goal of this survey is to obtain a better and unbiased understanding of the ``typical'' Seyfert X-ray spectrum (e.g. the distribution of their absorption column density) in the local Universe. This is crucial to verify the predictions and, thus, to validate unified models, and is a fundamental parameter of synthesis models for the X-ray background. A companion poster (paper II: L. Foschini et al., these proceedings) illustrates how this survey will also allow a comprehensive spectral study of the brightest (highest-luminosity) off-nuclear sources in the galaxies.

title: BeppoSAX uncovers the hidden Seyfert 1 nucleus in the Seyfert 2 galaxy NGC 2110
abstract: The Seyfert 2 galaxy NGC 2110 has been observed with BeppoSAX between 0.5 and 150 keV. The high energy instrument onboard, PDS, has succeeded in measuring for the first time the spectrum of this source in the 13-150 keV range. The PDS spectrum, having a photon index Gamma~1.86 is fully compatible with that expected from a Seyfert 1 nucleus. In the framework of unified models, the harder (Gamma~1.67) 2-10 keV spectrum is well explained assuming the presence of a complex partial + total absorber (Nh~30x10^22 cm^-2 x25% + Nh~4x10^22 cm^-2 x100%). The high column density of this complex absorber is consistent both with the FeK_alpha line strength and with the detection of an absorption edge at E~7.1 keV in the power-law spectrum.

title: A crucial hypothesis for Inflation
abstract: As is well known there are many different inflationary models that can explain the accelerated expansion occurred in the early Universe. It is possible that there exists a fundamental property of this period that could provide the corresponding field theory. Our hypothesis is that the Ricci scalar should assume a positive constant value during Inflation. Considering a single scalar field that drives the inflationary phase, we obtain uniquely the scalar potential and the coupling term between the scalar field and spacetime geometry. For this potential, that is well known in the inflationary scenario, the theoretical prediction of the spectral index ns is in perfect agreement with the experimental data. Interestingly in two dimensions, our model is equivalent to Liouville gravity.

title: Non-Abelian Chern-Simons Theory from a Hubbard-like Model
abstract: Here, we provide a simple Hubbard-like model of spin-1/2 fermions that gives rise to the SU(2)-symmetric Thirring model that is equivalent, in the low-energy limit, to the Yang-Mills-Chern-Simons model. First, we identify the regime that simulates the SU(2) Yang-Mills theory. Then, we suitably extend this model so that it gives rise to the SU(2) Chern-Simons theory with level k≥2 that can support non-Abelian anyons. This is achieved by introducing multiple fermionic species and modifying the Thirring interactions, while preserving the SU(2) symmetry. Our proposal provides the means to theoretically and experimentally probe non-Abelian SU(2) level k topological phases.

title: Abelian Chern-Simons-Maxwell theory from a tight-binding model of spinless fermions.
abstract: Abelian Chern-Simons-Maxwell theory can emerge from the bosonization of the (2+1)-dimensional Thirring model that describes interacting Dirac fermions. Here we show how the Thirring model manifests itself in the low energy limit of a two-dimensional tight-binding model of spinless fermions. To establish that, we employ a modification of Haldane's model, where the "doubling" of fermions is rectified by adiabatic elimination. Subsequently, fermionic interactions are introduced that lead to the analytically tractable Thirring model. By local density measurements of the lattice fermions we can establish that for specific values of the couplings the model exhibits the confining (2+1)-dimensional QED phase or a topological ordered phase that corresponds to the Chern-Simons theory. The implementation of the model as well as the measurement protocol are accessible with the current technology of cold atoms in optical lattices.

title: Topological effective field theories for Dirac fermions from index theorem
abstract: Dirac fermions have a central role in high energy physics but it is well known that they emerge also as quasiparticles in several condensed matter systems supporting topological order. We present a general method for deriving the topological effective actions of (3+1) massless Dirac fermions living on general backgrounds and coupled with vector and axial-vector gauge fields. The first step of our strategy is standard (in the Hermitian case) and consists in connecting the determinants of Dirac operators with the corresponding analytical indices through the zeta-function regularization. Then, we introduce a suitable splitting of the heat kernel that naturally selects the purely topological part of the determinant (i.e. the topological effective action). This topological effective action is expressed in terms of gauge fields using the Atiyah-Singer index theorem which computes the analytical index in topological terms. The main new result of this paper is to provide a consistent extension of this method to the non Hermitian case where a well-defined determinant does not exist. Quantum systems supporting relativistic fermions can thus be topologically classified on the basis of their response to the presence of (external or emergent) gauge fields through the corresponding topological effective field theories.

title: Gravitational Behaviour of an Effective Topological Field Theory
abstract: Effective topological field theories describe the properties of Dirac fermions in the low-energy regime. In this work, we introduce a new emergent gravity model by considering Dirac fermions invariant under local de Sitter transformations in four-dimensional open manifolds. In the context of Cartan geometry, fermions couple to spacetime through a $Spin(5)$ Cartan connection that can be decomposed in spin connection and tetrads. In presence of a gravitational instanton background, we show that the corresponding effective topological field theory becomes equivalent to a dynamical gravitational theory with positive cosmological constant and Barbero-Immirzi parameter. At classical level and in absence of matter, this theory is compatible with general relativity.