Galactic sources science with AGILE: The case of the Carina Region Sabatini, S.; Tavani, M.; Pian, E. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2011, Letnik:
630, Številka:
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Journal Article
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During its first 2 years of operation, the gamma-ray AGILE satellite accumulated an extensive dataset for the Galactic plane. The data have been monitored for transient sources and several gamma-ray ...sources were detected. Their variability and possible association were studied. In this talk we will focus on the results of extensive observations of the Carina Region during the time period 2007 July–2009 January, for a total livetime of
∼
130
days. The region is extremely complex, hosting massive star formation, with the remarkable colliding wind binary Eta Carinae, massive star clusters and HII regions (e.g. NGC 3324, RCW49, Westerlund II) and a giant molecular cloud extending over 150 pc (between
l=284.7 and 289). The Carina Nebula itself is the largest and IR highest surface brightness nebula of the Southern emisphere. We monitored several gamma ray sources in the Carina Region. In particular we detect a gamma ray source (1AGL J1043-5931) consistent with the position of Eta Carinae and report a remarkable 2-days gamma-ray flaring episode from this source on 2008 October 11–13. If 1AGL J1043-5931 is associated with the Eta Car system, our data provide the long sought first detection above 100
MeV of a colliding wind binary.
Super-massive black holes in active galaxies can accelerate particles to relativistic energies, producing jets with associated g-ray emission. Galactic 'microquasars', which are binary systems ...consisting of a neutron star or stellar-mass black hole accreting gas from a companion star, also produce relativistic jets, generally together with radio flares. Apart from an isolated event detected in CygnusX-1, there has hitherto been no systematic evidence for the acceleration of particles to gigaelectronvolt or higher energies in a microquasar, with the consequence that we are as yet unsure about the mechanism of jet energization. Here we report four g-ray flares with energies above 100MeV from the microquasar CygnusX-3 (an exceptional X-ray binary that sporadically produces radio jets). There is a clear pattern of temporal correlations between the g-ray flares and transitional spectral states of the radio-frequency and X-ray emission. Particle acceleration occurred a few days before radio-jet ejections for two of the four flares, meaning that the process of jet formation implies the production of very energetic particles. In CygnusX-3, particle energies during the flares can be thousands of times higher than during quiescent states.
The 18O(p,α)15N reaction rate has been deduced by means of the Trojan horse method. For the first time the contribution of the 20 keV resonance has been directly evaluated, giving a value about 35% ...larger than the one in the literature. Moreover, the present approach has allowed to improve the accuracy by a factor 8.5, as it is based on the measured strength instead of spectroscopic measurements. The contribution of the 90 keV resonance has been also determined, which turned out to be of negligible importance to astrophysics.
We summarize the inflight performance of JEM–X, the X–ray monitor on the INTEGRAL mission during the initial ten months of operations. The JEM–X instruments have now been tuned to stable operational ...conditions. The performance is found to be close to the pre-launch expectations. The ground calibrations and the inflight calibration data permit to determine the instruments characteristics to fully support the scientific data analysis.
Edizione di un frammento di un testo alchemico in volgare siciliano conservato in un ms. miscellaneo della Biblioteca Nazionale di Firenze (ms. Palatino 945, cc. 145-146). L’esistenza di una ...tradizione alchemica siciliana è desumibile da varie fonti e si possono rintracciare vari testi in lingua latina di probabile ascendenza siciliana, ma sinora non erano mai stati identificati ed editati testi interamente in volgare ; questo frammento in particolare doveva appartenere a un trattato di una certa lunghezza e sistematicità, tipologia non troppo frequente in volgare prima del secolo XVI.
The Sicilian alchemical tradition can be traced back to various sources, allowing for the possibility that some texts in Latin were probably written in Sicily during the Middle Ages. Before the discovery of present text, the subject of this essay’s edition, no works written entirely in Sicilian vernacular were known by literary historians. This fragment, found in the Biblioteca Nazionale in Florence (Palatino 945, cc. 145-146), probably comes from a long and systematic treatise, now lost. This kind of treatise was not very frequent in vernacular languages before the XVIthcentury.
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