Un prédicateur au cachot. Guillaume Adeline et le sabbat.

Résumé: En 1453, le prédicateur et maître en théologie Guillaume Adeline est inculpé par l'évêque d'Évreux et l'inquisition pour son appartenance, depuis la fin des années 1430, à des sectes de sorciers présidées par des démons. Il est accusé également d'avoir prêché que le sabbat n'existe pas réellement et que le vol des sorcières est une illusion produite par le diable dans l'esprit des hommes. Ce faux prédicateur permettrait ainsi à ces sectes de développer. Cette affaire met en lumière le débat du xve siècle relatif au sabbat, réalité ou rêve diabolique. Pour certains démonologues français, à l'instar de Nicolas Jacquier ou Pierre Mamoris, le cas exemplaire d'Adeline tombe à point nommé pour démontrer la gravité des manifestations démoniaques parmi les hommes et dénoncer la prolifération de sectes hétérodoxes, en incitant à la répression judiciaire. Abstract: In 1453, Guillaume Adeline, preacher and master of theology, is arrested by the bishop of Évreux and the inquisition. Since the end of the 1430's, he was accused of belonging to diabolical sects of witches, mainly because he preached the non-existence of the witches'sabbath, and proclaimed that the flight of witches was an illusion instilled in men's spirit by the devil, thus favoring the spread of those sects. This affair shows the importance of the fifteenth century debate about the sabbath, be it a reality or a diabolical dream. Some french demonologues such as Nicolas Jacquier or Pierre Mamoris stress out Adeline's exemplary case as an opportunity for asserting the seriousness of diabolical manifestions among the people, for denouncing the proliferation of heterodox sects, and for inciting judicial proceedings

Itinéraire d'un inquisiteur gâté: Ponce Feugeyron, les juifs et le sabbat des sorciers

Itinerary of a spoiled inquisitor : Ponce Feugeyron, the Jews and the witches' sabbath - A Franciscan living in the first half of the fifteenth century, Ponce Feugeyron was an inquisitor whose activities spread over Jews, heretics and witches. He covered an area wich included nearly all of Southeastern France, from Avigon throught the Dauphiné to the duchy of Savoy. He might also be the author of one of the very first texts mentioning the witches' sabbath, namely Errores gazariorum (errors of the « Gazari »), an anonymous treatise written in the Aosta Valley around 1436.Dans la première moitié du XVe siècle, l'inquisiteur franciscain Ponce Feugeyron est mandaté par le pape Alexandre V pour agir tant contre les juifs et les judaïsants que contre les sectes d'hérétiques et de sorciers. Son rayon d'action couvre tout le Sud-Est de la France, d'Avignon au duché de Savoie en passant par le Dauphiné. On examine ici l'hypothèse qu'il pourrait être l'auteur des Errores gazariorum, l'un des plus anciens textes présentant l'imaginaire du sabbat, écrit dans le val d'Aoste vers 1436.Ostorero Martine. Itinéraire d'un inquisiteur gâté : Ponce Feugeyron, les juifs et le sabbat des sorciers. In: Médiévales, n°43, 2002. Le bain : espaces et pratiques, sous la direction de Didier Boisseuil . pp. 103-117

X-ray Emitting GHz-Peaked Spectrum Galaxies: Testing a Dynamical-Radiative Model with Broad-Band Spectra

In a dynamical-radiative model we recently developed to describe the physics of compact, GHz-Peaked-Spectrum (GPS) sources, the relativistic jets propagate across the inner, kpc-sized region of the host galaxy, while the electron population of the expanding lobes evolves and emits synchrotron and inverse-Compton (IC) radiation. Interstellar-medium gas clouds engulfed by the expanding lobes, and photoionized by the active nucleus, are responsible for the radio spectral turnover through free-free absorption (FFA) of the synchrotron photons. The model provides a description of the evolution of the spectral energy distribution (SED) of GPS sources with their expansion, predicting significant and complex high-energy emission, from the X-ray to the gamma-ray frequency domain. Here, we test this model with the broad-band SEDs of a sample of eleven X-ray emitting GPS galaxies with Compact-Symmetric-Object (CSO) morphology, and show that: (i) the shape of the radio continuum at frequencies lower than the spectral turnover is indeed well accounted for by the FFA mechanism; (ii) the observed X-ray spectra can be interpreted as non-thermal radiation produced via IC scattering of the local radiation fields off the lobe particles, providing a viable alternative to the thermal, accretion-disk dominated scenario. We also show that the relation between the hydrogen column densities derived from the X-ray (N_H) and radio (N_HI) data of the sources is suggestive of a positive correlation, which, if confirmed by future observations, would provide further support to our scenario of high-energy emitting lobes.Comment: 29 pages, 3 figures, 6 tables; to appear in ApJ. A few clarifications included, according to referee's suggestion

The long-term optical spectral variability of BL Lacertae

We present the results from a study of the long-term optical spectral variations of BL Lacertae, using the long and well-sampled B and R-band light curves of the Whole Earth Blazar Telescope (WEBT) collaboration, binned on time intervals of 1 day. The relation between spectral slope and flux (the spectrum gets bluer as the source flux increases) is well described by a power-law model, although there is significant scatter around the best-fitting model line. To some extent, this is due to the spectral evolution of the source (along well-defined loop-like structures) during low-amplitude events, which are superimposed on the major optical flares, and evolve on time scales of a few days. The "bluer-when-brighter" mild chromatism of the long-term variations of the source can be explained if the flux increases/decreases faster in the B than in the R band. The B and R-band variations are well correlated, with no significant, measurable delays larger than a few days. On the other hand, we find that the spectral variations lead those in the flux light curves by ~ 4 days. Our results can be explained in terms of Doppler factor variations due to changes in the viewing angle of a curved and inhomogeneous emitting jet.Comment: 7 pages, 5 figures, accepted for publication in A&

The nature of optical and near-infrared variability of BL Lacertae

Since 1997, BL Lacertae has undergone a phase of high optical activity, with the occurrence of several prominent outbursts. Starting from 1999, the Whole Earth Blazar Telescope (WEBT) consortium has organized various multifrequency campaigns on this blazar, collecting tens of thousands of data points. One of the main issues in the analysis of this huge dataset has been the study of colour variability. The massive amount of optical and near-infrared data collected during the campaigns enables us to perform a deep analysis of multiband data, with the aim of understanding the flux variability mechanisms. We use a new approach for the analysis of these data, focusing on the source spectral evolution. We show that the overall behaviour of the BL Lacertae light and colour curves can be explained in terms of changing viewing angle of a moving, discrete emitting region, which causes variable Doppler boosting of the corresponding radiation. A fractal helical structure is suggested to be at the origin of the different time scales of variability.Comment: 6 pages, 8 figures, accepted by A&

Mid-Infrared Diagnostics of the Circumnuclear Environments of the Youngest Radio Galaxies

We present a systematic analysis of the mid-infrared (MIR) properties of the youngest radio galaxies, based on low-resolution data provided by the {\it WISE} and {\it IRAS} satellites. We restrict our analysis to sources with available X-ray data that constitute the earliest phase of radio galaxy evolution, i.e. those classified as Gigahertz Peaked Spectrum (GPS) and/or Compact Symmetric Objects (CSOs). In our sample of 29 objects, we find that the host galaxies are predominantly red/yellow ellipticals, with some of them displaying distorted morphology. We find a variety of MIR colors, and observe that the sources in which the MIR emission is dominated by the ISM component uniformly populate the region occupied by galaxies with a wide range of pronounced ($\geq 0.5 M_{\odot}$\,yr$^{-1}$) star formation activity. We compare the MIR color distribution in our sample to that in the general population of local AGN, in the population of evolved FR\,II radio galaxies, and also in the population of radio galaxies with recurrent jet activity. We conclude that the triggering of radio jets in AGN does not differentiate between elliptical hosts with substantially different fractions of young stars; instead there is a relationship between the jet duty cycle and the ongoing star formation. The distribution of the sub-sample of our sources with $z<0.4$ on the low-resolution MIR vs. absorption-corrected X-ray luminosity plane is consistent with the distribution of a sample of local AGN. Finally, we comment on the star formation rates of the two $\gamma$-ray detected sources in our sample, 1146+596 \& 1718--649.Comment: Revised version, accepted by the Astrophysical Journa