Anna Maria Di Giorgio

Gamma-Light: High-Energy Astrophysics above 10 MeV

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.

SAFARI new and improved: extending the capabilities of SPICA's imaging spectrometer

The Japanese SPace Infrared telescope for Cosmology and Astrophysics, SPICA, aims to provide astronomers with a truly new window on the universe. With a large -3 meter class- cold -6K- telescope, the mission provides a unique low background environment optimally suited for highly sensitive instruments limited only by the cosmic background itself. SAFARI, the SpicA FAR infrared Instrument SAFARI, is a Fourier Transform imaging spectrometer designed to fully exploit this extremely low far infrared background environment. The SAFARI consortium, comprised of European and Canadian institutes, has established an instrument reference design based on a Mach-Zehnder interferometer stage with outputs directed to three extremely sensitive Transition Edge Sensor arrays covering the 35 to 210 μm domain. The baseline instrument provides R > 1000 spectroscopic imaging capabilities over a 2’ by 2’ field of view. A number of modifications to the instrument to extend its capabilities are under investigation. With the reference design SAFARI’s sensitivity for many objects is limited not only by the detector NEP but also by the level of broad band background radiation – the zodiacal light for the shorter wavelengths and satellite baffle structures for the longer wavelengths. Options to reduce this background are dedicated masks or dispersive elements which can be inserted in the optics as required. The resulting increase in sensitivity can directly enhance the prime science goals of SAFARI; with the expected enhanced sensitivity astronomers would be in a better position to study thousands of galaxies out to redshift 3 and even many hundreds out to redshifts of 5 or 6. Possibilities to increase the wavelength resolution, at least for the shorter wavelength bands, are investigated as this would significantly enhance SAFARI’s capabilities to study star and planet formation in our own galaxy.

The European contribution to the SPICA mission

The Japanese led Space Infrared telescope for Cosmology and Astrophysics (SPICA) will observe the universe over the 5 to 210 micron band with unprecedented sensitivity owing to its cold (~5 K) 3.5m telescope. The scientific case for a European involvement in the SPICA mission has been accepted by the ESA advisory structure and a European contribution to SPICA is undergoing an assessment study as a Mission of Opportunity within the ESA Cosmic Vision 1015-2015 science mission programme. In this paper we describe the elements that are being studied for provision by Europe for the SPICA mission. These entail ESA directly providing the cryogenic telescope and ground segment support and a consortium of European insitutes providing a Far Infrared focal plane instrument. In this paper we describe the status of the ESA study and the design status of the FIR focal plane instrument.

C 3, A Command-line Catalog Cross-match Tool for Large Astrophysical Catalogs

Modern Astrophysics is based on multi-wavelength data organized into large and heterogeneous catalogs. Hence, the need for efficient, reliable and scalable catalog cross-matching methods plays a crucial role in the era of the petabyte scale. Furthermore, multi-band data have often very different angular resolution, requiring the highest generality of cross-matching features, mainly in terms of region shape and resolution. In this work we present C 3 (Command-line Catalog Cross-match), a multi-platform application designed to efficiently cross-match massive catalogs. It is based on a multi-core parallel processing paradigm and conceived to be executed as a stand-alone command-line process or integrated within any generic data reduction/analysis pipeline, providing the maximum flexibility to the end-user, in terms of portability, parameter configuration, catalog formats, angular resolution, region shapes, coordinate units and cross-matching types. Using real data, extracted from public surveys, we discuss the cross-matching capabilities and computing time efficiency also through a direct comparison with some publicly available tools, chosen among the most used within the community, and representative of different interface paradigms. We verified that the C 3 tool has excellent capabilities to perform an efficient and reliable cross-matching between large data sets. Although the elliptical cross-match and the parametric handling of angular orientation and offset are known concepts in the astrophysical context, their availability in the presented command-line tool makes C 3 competitive in the context of public astronomical tools.

Machine Learning Based Data Mining for Milky Way Filamentary Structures Reconstruction

We present an innovative method called FilExSeC (Filaments Extraction, Selection and Classification), a data mining tool developed to investigate the possibility to refine and optimize the shape reconstruction of filamentary structures detected with a consolidated method based on the flux derivative analysis, through the column-density maps computed from Herschel infrared Galactic Plane Survey (Hi-GAL) observations of the Galactic plane. The present methodology is based on a feature extraction module followed by a machine learning model (Random Forest) dedicated to select features and to classify the pixels of the input images. From tests on both simulations and real observations the method appears reliable and robust with respect to the variability of shape and distribution of filaments. In the cases of highly defined filament structures, the presented method is able to bridge the gaps among the detected fragments, thus improving their shape reconstruction. From a preliminary a posteriori analysis of derived filament physical parameters, the method appears potentially able to add a sufficient contribution to complete and refine the filament reconstruction.

Large-scale latitude distortions of the inner Milky Way disk from the Herschel/Hi-GAL Survey

Aims. We use the Herschel Hi-GAL survey data to study the spatial distribution in Galactic longitude and latitude of the interstellar medium and of dense, star-forming clumps in the inner Galaxy. Methods. We assemble a complete mosaic of the inner Galaxy between l = 70 and +68 in the far-infrared continuum from HiGAL. The peak position and width of the latitude distribution of the dust column density is analysed by fitting a polynomial function to the di use IR surface brightness in 1 longitude bins and the result is compared to MIPSGAL 24- m data. The latitude distribution of number density of compact sources from the band-merged Hi-GAL photometric catalogues is also analysed as a function of longitude. Results. The width of the di use dust column density traced by the Hi-GAL 500- m emission varies across the inner Galaxy, with a mean value of 1 .2 1 .3, similar to that of the distribution of MIPSGAL 24- m sources and of Hi-GAL sources with a 250- m counterpart. Hi-GAL sources with a 70- m counterpart define a much thinner disk, with a mean FWHM 0 .75, in excess of the result obtained by the ATLASGAL submillimetre survey. The discrepancy with the 250- m source distribution can be explained by relatively higher confusion in the Herschel data in the midplane region. The peak of the average latitude distribution of Hi-GAL sources is at b 0 .06, coincident with the results from ATLASGAL. The detailed latitude distribution as a function of longitude shows clear modulations, both for the di use emission and for the compact sources. The displacements are mostly toward negative latitudes, with excursions of 0 .2 below the midplane at l +40 , +12 , 25 and 40 . The only positive bend peaks at l 5 . No such modulations can be found in the MIPSGAL 24 m or WISE 22 m data when the entire source samples are considered; modulations in part similar to the ones exhibited by the Herschel sources appear when the mid-infrared catalogues are filtered according to criteria that preferentially select YSOs. Conclusions. The distortions of the Galactic inner disk revealed by Herschel confirm previous findings from CO surveys and HII/OB source counts but with much greater statistical significance and are interpreted as large-scale bending modes of the Plane. The lack of similar distortions in tracers of more evolved YSOs or stars rules out gravitational instabilities or satellite-induced perturbations, as they should act on both the di use and stellar disk components. We propose that the observed bends are caused by incoming flows of extra-planar gas from the Galactic fountain or the Galactic halo interacting with the gaseous disk. Stars, having a much lower cross-section, decouple from the gaseous ISM and relax into the stellar disk potential. The timescale required for the disappearance of the distortions from the di use ISM to the relatively evolved YSO stages are compatible with star-formation timescales.

The Command and Data processing Unit of the Euclid Visible Imager: impact of the data compression needs on the unit design

The Command and Data Processing Unit (CDPU) of the Euclid Visible Imager is one of the two warm electronics units of the instrument. It implements on one side the digital interface to the satellite, for telecommands acquisition and telemetry downloading, and on the other side the interface to the focal plane CCDs readout electronics, for science data acquisition and compression. The CDPU main functionalities include the instrument commanding, control and health monitoring. The baseline unit architecture is presented, reporting the results of the phase B1 study and of the trade-off activity carried out to check the performances of the SW implementation of two different lossless compression algorithms on the baseline target processor (LEON3-FT) and on a HW compressor.

The data handling unit of the Euclid imaging channels: from the observational requirements to the unit architecture

The Euclid Imaging Channels Instrument of the Euclid mission is designed to study the weak gravitational lensing cosmological probe. The combined Visible and Near Infrared imaging channels will be controlled by a common data handling unit (PDHU), implementing onboard the instrument digital interfaces to the satellite. The PDHU main functionalities include the scientific data acquisition and compression, the instrument commanding and control and the instrument health monitoring. Given the high data rate and the compression needs, an innovative architecture, based on the use of several computing and interface modules, considered as building blocks of a modular design will be presented.

The design of the instrument control unit and its role within the data processing system of the ESA PLATO Mission

PLATO1 is an M-class mission of the European Space Agency’s Cosmic Vision program, whose launch is foreseen by 2026. PLAnetary Transits and Oscillations of stars aims to characterize exoplanets and exoplanetary systems by detecting planetary transits and conducting asteroseismology of their parent stars. PLATO is the next generation planetary transit space experiment, as it will fly after CoRoT, Kepler, TESS and CHEOPS; its objective is to characterize exoplanets and their host stars in the solar neighbors. While it is built on the heritage from previous missions, the major breakthrough to be achieved by PLATO will come from its strong focus on bright targets, typically with mv≤11. The PLATO targets will also include a large number of very bright and nearby stars, with mv≤8. The prime science goals characterizing and distinguishing PLATO from the previous missions are: the detection and characterization of exoplanetary systems of all kinds, including both the planets and their host stars, reaching down to small, terrestrial planets in the habitable zone; the identification of suitable targets for future, more detailed characterization, including a spectroscopic search for biomarkers in nearby habitable exoplanets (e.g. ARIEL Mission scientific case, E-ELT observations from Ground); a full characterization of the planet host stars, via asteroseismic analysis: this will provide the Community with the masses, radii and ages of the host stars, from which masses, radii and ages of the detected planets will be determined.

Milky way analysis through a Science Gateway: workflows and resource monitoring

This paper presents the latest developments on the VIALACTEA Science Gateway in the context of the FP7 VIALACTEA project. This science gateway operates as a central workbench for the VIALACTEA community in order to allow astronomers to process the new-generation (from Infrared to Radio) surveys of the Galactic Plane to build and deliver a quantitative 3D model of our Milky Way Galaxy. The final model will be used as a template for external galaxies to study star formation across the cosmic time. The adopted AGILE software development process allowed to fulfill the community needs in terms of required workflows and underlying resources monitoring. The scientific requirements arose during the process highlighted the needs for easy parameter setting, fully embarrassingly parallel computations and large-scale input dataset processing. Therefore the science gateway based on the WS-PGRADE/gUSE framework has been able to fulfill the requirements mainly exploiting the parameter sweep paradigm and parallel jobs execution of the workflow management system. Moving from the development to the production environment an efficient resource monitoring system has been implemented to easily analyse and debug sources of failure due to workflows computations. The results of the resource monitoring system are exploitable not only for IT experts administrators and workflow developers but also for the final users of the gateway. The affiliation to the STARnet Gateway Federation ensures the sustainability of the presented products after the end of the project, allowing the usage of VIALACTEA Science Gateway to all the stakeholders and not only to the community members. Keywords—Workflow Systems; Science Gateways; Collaborative Environments; Astrophysics; DCIs; Milky Way Analysis; Infrastructure Tests; Monitoring