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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 (https://tools.asdc.asi.it/SED) and by means of interactive tables (http://www.asdc.asi.it/xrtspectra). Innovative data visualisation methods (see e.g. http://youtu.be/nAZYcXcUGW8) are also being developed at ASDC to better exploit this remarkable and rapidly growing data set. © 2015 Elsevier B.V.

Santangelo G.,Osservatorio Astrofisico di Arcetri | Santangelo G.,National institute for astrophysics | Antoniucci S.,National institute for astrophysics | Nisini B.,National institute for astrophysics | And 13 more authors.
Astronomy and Astrophysics | Year: 2014

Methods: We present new high spectral resolution observations of H0-0 S(4), 0-0 S(9), and 1-0 S(1) towards HH 54, a bright nearby shock region in the southern sky. In addition, new Herschel/HIFI H (2- 1 observations at 1670 GHz are presented.Herschel observations suggest that the H distribution in outflows from low-mass stars resembles the Hemission. It is still unclear which of the different excitation components that characterise the mid- and near-IR Hdistribution is associated with H.Aims: The aim is to spectrally resolve the different excitation components observed in the Hemission. This will allow us to identify the Hcounterpart associated with H and finally derive directly an H abundance estimate with respect to HResults: Our observations show for the first time a clear separation in velocity of the different Hlines: the 0-0 S(4) line at the lowest excitation peaks at -7 km s-1, while the more excited 0-0 S(9) and 1-0 S(1) lines peak at -15 km s-1. H and high-J CO appear to be associated with the H0-0 S(4) emission, which traces a gas component with a temperature of 700-1000 K. The H abundance with respect to H0-0 S(4) is estimated to be X(H) < 1.4 10-5 in the shocked gas over an area of 13''.Conclusions: We resolve two distinct gas components associated with the HH 54 shock region at different velocities and excitations. This allows us to constrain the temperature of the H emitting gas (≤1000 K) and to derive correct estimates of H abundance in the shocked gas, which is lower than what is expected from shock model predictions.

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.

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).

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.

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