Rome, Italy
Rome, Italy

Time filter

Source Type

Giommi P.,ASDC | Giommi P.,Brazilian Center for Research in Physics (CBPF)
Journal of High Energy Astrophysics | Year: 2015

During its first 10 years of orbital operations Swift dedicated approximately 11% of its observing time to blazars, carrying out more than 12,000 observations of ~1600 different objects, for a total exposure time of over 25 million seconds. In this paper I briefly discuss the impact that Swift is having on blazar multi-frequency and time-domain astrophysics, as well as how it is contributing to the opening of the era of multi-messenger astronomy. Finally, I present some preliminary results from a systematic analysis of a very large number of Swift XRT observations of blazars. All the "science ready" data products that are being generated by this project will be publicly released. Specifically, deconvolved X-ray spectra and best fit spectral parameters will be available through the ASDC "SED builder" tool ( and by means of interactive tables ( Innovative data visualisation methods (see e.g. are also being developed at ASDC to better exploit this remarkable and rapidly growing data set. © 2015 Elsevier B.V.

Morselli A.,University of Rome Tor Vergata | Argan A.,National institute for astrophysics | Barbiellini G.,National Institute of Nuclear Physics, Italy | Barbiellini G.,University of Trieste | And 41 more authors.
Nuclear Physics B - Proceedings Supplements | Year: 2013

The energy range between 10 and 50 MeV is an experimentally very difficult range and remained uncovered since the time of COMPTEL. Here we propose a possible mission to cover this energy range. © 2013 Elsevier B.V.

Dirri F.,Istituto di Astrofisica Spaziale e Fisica Cosmica | Dirri F.,University of Rome La Sapienza | Palomba E.,Istituto di Astrofisica Spaziale e Fisica Cosmica | Longobardo A.,Istituto di Astrofisica Spaziale e Fisica Cosmica | And 5 more authors.
Memorie della Societa Astronomica Italiana - Journal of the Italian Astronomical Society | Year: 2014

In this work, we present a new experimental set up to infer the enthalpy of sublimation for a known specie of dicarboxylic acid, i.e. adipic acid. This type of acids, with various concentrations are present in different environments (e.g. marine, rural, urban). The experiment is performed in the framework of the VISTA (Volatile In Situ Thermogravimetry Analyser) project, an instrument currently under study for the ESA Cosmic Vision proposed mission MarcoPolo-R. The enthalpy of sublimation of adipic acid was measured by means of micro-thermogravimetric analysis (μ-TGA), a widely used technique to investigate condensation/sublimation and absorption/desorption processes of volatile compounds. The measurements were performed with a 10 MHz temperature controlled piezoelectric crystal microbalance (PCM), placed in a vacuum chamber (10-6 mbar). The obtained enthalpy of sublimation is (123 ± 16) kJ × mol -1, a value in good agreement with literature within 10%. This result (connected to the deposition rate curve, from 30° to 75°C), demonstrates the capability of our device to perform this kind of measurements. © SAIt 2014.

Dall'Osso S.,National institute for astrophysics | Stratta G.,ASDC | Guetta D.,National institute for astrophysics | Covino S.,National institute for astrophysics | And 4 more authors.
Astronomy and Astrophysics | Year: 2011

Aims. We investigate a model for the shallow decay phases of gamma-ray burst (GRB) afterglows discovered by Swift/XRT in the first hours following a GRB event. In the context of the fireball scenario, we consider the possibility that long-lived energy injection from a millisecond spinning, ultramagnetic neutron star (magnetar) powers afterglow emission during this phase. Methods. We consider the energy evolution in a relativistic shock that is subject to both radiative losses and energy injection from a spinning down magnetar in spherical symmetry. We model the energy injection term through magnetic dipole losses and discuss an approximate treatment for the dynamical evolution of the blastwave. We obtain an analytic solution for the energy evolution in the shock and associated lightcurves. To fully illustrate the potential of our solution we calculate lightcurves for a few selected X-ray afterglows observed by Swift and fit them using our theoretical lightcurves. Results. Our solution naturally describes in a single picture the properties of the shallow decay phase and the transition to the so-called normal decay phase. In particular, we obtain remarkably good fits to X-ray afterglows for plausible parameters of the magnetar. Even though approximate, our treatment provides a step forward with respect to previously adopted approximations and provides additional support of the idea that a millisecond spinning (1-3 ms), ultramagnetic (B ~ 10 14-1015 G) neutron star loosing spin energy through magnetic dipole radiation can explain the luminosity, durations and shapes of X-ray GRB afterglows. © ESO, 2011.

D'Urso D.,ASDC | D'Urso D.,National Institute of Nuclear Physics, Italy | Duranti M.,National Institute of Nuclear Physics, Italy | Duranti M.,University of Perugia
Journal of Physics: Conference Series | Year: 2015

Data access and availability is a crucial issue in high energy physics (HEP) experiments, given the huge amount of data produced. We present a flexible and modular data format implementation for HEP applications. It has been designed to modularize data in order to update the minimum amount of event information in case of bug correction, software updates or data format extension, to simplify data distribution and upgrades to the regional data centers, and to reduce the amount of data to be transferred to data members really affected by reprocessing. The proposed design and implementation has been developed as mini-DST data format for the Alpha Magnetic Spectrometer (AMS [1]) experiment on the International Space Station (ISS) and is based on the CERN ROOT [2] toolkit. © Published under licence by IOP Publishing Ltd.

Sapunenko V.,National Institute of Nuclear Physics, Italy | D'Urso D.,ASDC | D'Urso D.,National Institute of Nuclear Physics, Italy | Dell'Agnello L.,National Institute of Nuclear Physics, Italy | And 3 more authors.
Journal of Physics: Conference Series | Year: 2015

Data management constitutes one of the major challenges that a geographically- distributed e-Infrastructure has to face, especially when remote data access is involved. We discuss an integrated solution which enables transparent and efficient access to on-line and near-line data through high latency networks. The solution is based on the joint use of the General Parallel File System (GPFS) and of the Tivoli Storage Manager (TSM). Both products, developed by IBM, are well known and extensively used in the HEP computing community. Owing to a new feature introduced in GPFS 3.5, so-called Active File Management (AFM), the definition of a single, geographically-distributed namespace, characterised by automated data flow management between different locations, becomes possible. As a practical example, we present the implementation of AFM-based remote data access between two data centres located in Bologna and Rome, demonstrating the validity of the solution for the use case of the AMS experiment, an astro-particle experiment supported by the INFN CNAF data centre with the large disk space requirements (more than 1.5 PB).

Gendre B.,ASDC | Atteia J.L.,Toulouse 1 University Capitole | Atteia J.L.,French National Center for Scientific Research | Boer M.,Artemis | And 10 more authors.
Astrophysical Journal | Year: 2012

The Swift burst GRB 110205A was a very bright burst visible in the Northern Hemisphere. GRB 110205A was intrinsically long and very energetic and it occurred in a low-density interstellar medium environment, leading to delayed afterglow emission and a clear temporal separation of the main emitting components: prompt emission, reverse shock, and forward shock. Our observations show several remarkable features of GRB 110205A: the detection of prompt optical emission strongly correlated with the Burst Alert Telescope light curve, with no temporal lag between the two; the absence of correlation of the X-ray emission compared to the optical and high-energy gamma-ray ones during the prompt phase; and a large optical re-brightening after the end of the prompt phase, that we interpret as a signature of the reverse shock. Beyond the pedagogical value offered by the excellent multi-wavelength coverage of a gamma-ray burst with temporally separated radiating components, we discuss several questions raised by our observations: the nature of the prompt optical emission and the spectral evolution of the prompt emission at high energies (from 0.5keV to 150keV); the origin of an X-ray flare at the beginning of the forward shock; and the modeling of the afterglow, including the reverse shock, in the framework of the classical fireball model. © 2012 The American Astronomical Society. All rights reserved.

Stratta G.,ASDC | Guetta D.,National institute for astrophysics | D'Elia V.,ASDC | Perri M.,ASDC | And 2 more authors.
AIP Conference Proceedings | Year: 2010

Several studies have addressed the intrinsic properties of the X-ray shallow phase, in particular by testing whether a dependence exists between the intrinsic duration of the shallow phase and the burst energetics. Results obtained so far are discordant, possibly due to the large uncertainties affecting the burst energetics estimates and/or in modeling the X-ray shallow phase and estimating the temporal break between the shallow and the standard phases. In this work we have constructed a GRB sample according to the following selection criteria: i) a 0.3-10 keV XRT lightcurve featuring shallow behavior with temporal index α < 0.8 over a temporal interval greater than 0.5 ks (so that the power-law decay index can be measured accurately); ii) the shallow decay interval should not be dominated by features such as "bumps" or flares that may affect the measurement of the decay index. In addition, we requested well defined GRB prompt spectral properties that enable a secure energy (Eiso) estimate of the burst. Although a much larger sample is needed, our results favor the existence of a dependence of the intrinsic shallow phase duration from Eiso and from the X-ray luminosity at the end of the shallow phase. Considering also those GRBs with excellent XRT data monitoring with no evidence of shallow phase and with decay index consistent on average with the post-plateau phase, we find that these epochs are consistent with the extrapolation of the burst energy and X-ray luminosity anticorrelations found for those GRBs with evidence of a plateau in their X-ray light curves. © 2010 American Institute of Physics.

Stratta G.,ASDC | Capalbi M.,ASDC | Perri M.,ASDC | Giommi P.,Earth Observation Directorate
AIP Conference Proceedings | Year: 2010

We present the Swift/XRT Interactive Archive and the On-line Analysis tool developed at the ASI Science Data Center (ASDC) as part of the Multi Mission Interactive Archive. The On-line Analysis enables to run the Swift/XRT software task "xrtpipeline" on any desired XRT observation present in the Swift data archive maintained at ASDC, directly on the web. On-line imaging (with XIMAGE), spectral (with XSPEC) and timing data analysis (with LCURVE) can be performed. At the same time, spectra, light curves, effective area, exposure map and response matrix are promptly available for download to the user for any off-line analysis. © 2010 American Institute of Physics.

Calzoletti L.,ASDC | Faustini F.,ASDC | Molinari S.,National institute for astrophysics | DiGiorgio A.M.,National institute for astrophysics
Memorie della Societa Astronomica Italiana - Journal of the Italian Astronomical Society | Year: 2012

Herschel is an ESA mission planned as a Space Observatory: it hosts the largest telescope ever launched into space with a 3.5-metres monolithic primary mirror. The mission has been designed to operate in a wide spectral domain that goes from the far infrared up to the sub millimeter and the three scientific instruments on the focal plane (PACS, SPIRE and HIFI) can execute spectroscopy and photometry in the 55-670/m range. Herschel is optimised to observe the coldest regions in the Universe and it is expected to reveal new information about the earliest, most distant stars and galaxies. It will also take a unique look at our own solar system. Half of the Herschel observing time is still allocated to Key Programmes, while the remaining "Open Time" is available for the worldwide scientific community and will be allocated using a standard proposal procedure, through Announcement of Opportunities. The ASI Science Data Center (ASDC) provides a widerange support to the Italian astronomical community interested in the mission opportunities. ASDC provides assistance for the preparation and submission of proposals, for the data processing and for the installation and usage of specific tools dedicated to the scientific analysis. Specific tutorials on the mission characteristics (satellite, instruments) and on the data reduction/analysis methods guarantee an adequate knowledge transfer of the instrumental and data analysis expertise from ASDC personnel to the interested astronomers. © SAIt 2012.

Loading ASDC collaborators
Loading ASDC collaborators