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ASDC Newsletter #14

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The first Gaia data release (Gaia DR1)

The ESA Gaia satellite, lauched in december 2013, is performing an all-sky survey to obtain positions, parallaxes and proper motions to microarcsec precision for more than one billion point-like sources on the sky. The astrometric data are complemented by low-resolution spectrophotometric data in the 330-1050 nm wavelength range and, for the brightest stars (V<16 mag), by radial velocity measurements  in the spectral region centered around the calcium triplet (845-872 nm).

The first Gaia data release (Gaia DR1) is online since September 14, 2016.
The Gaia DR1 data are available at ASDC: the GaiaPortal@ASDC is part of a network of five European-based data centers that distribute the Gaia catalogue released data (starting from DR1). GaiaPortal@ASDC's primary objective is to foster the scientific exploitation of the 10-15 TB of released information (at mission end) by the Italian and international community through data access and dedicated analysis tools (in particular the cross-match with large external surveys).


Gaia DR1 contains:
 • Positions and G magnitude for all sources with acceptable formal standard errors on positions.
 • The five-parameter astrometric solution (positions, parallaxes, and proper motions) for stars in common between the Tycho-2 Catalogue and Gaia. This part of Gaia DR1 is based on the Tycho-Gaia Astrometric Solution (TGAS).
 • Photometric data of selected RR Lyrae and Cepheid variable stars including the objects characterization and time-series.
 • Positions and G magnitudes for 2191 ICRF quasars
 • Cross-matches are provided between Gaia sources and 2MASS PSC, GSC2.3, PPMXL, UCAC4, SDSS DR9, allWISE, and URAT-1 data.

The official cross-match of Gaia data with external surveys was developed and realized in ASDC. It is a many-to-one cross-match based on objects positions, positional errors, proper motions (when available) and local stellar surface density  (ASDC/INAF Gaia team interview, INAF news, ASI newsESA media kit, and read more).

    

   

AMS-02 measurement of antiprotons in cosmic rays

The AMS-02 (Alpha Magnetic Spectrometer) experiment, on the International Space Station, has reported precision measurements of antiprotons in primary cosmic rays at energies never reached before. 
The analysis, based on 3.49 X 105 antiproton events and 2.42 X 109 proton events, uses the first four years of data. This AMS-02 data represent new and unexpected observations of the properties of elementary particles in the cosmos.
Launched in May 2011, AMS-02 is a 7.5 tons detector module that measures the type, energy and direction of particles. The goals of AMS-02 are to use its unique position in space to search for dark matter and antimatter, and to study the origin and propagation of charged cosmic rays: electrons, positrons, protons, antiprotons and nuclei.
With its latest antiproton results, AMS-02 has now simultaneously measured all of the charged-elementary-particle cosmic-ray fluxes and flux ratios. 
Due to the low abundance of antiprotons in space (being outnumbered by protons by a factor 10,000), experimental data on antiprotons was limited. The AMS measurements, which demanded a separation power of approximately 106, provide precise experimental information over an extended energy range in the study of elementary particles travelling through space.
In the absolute-rigidity (the absolute value of the momentum/charge) range 60-500 GV, the antiproton (p), proton (p), and positron (e+) fluxes are found to have nearly identical rigidity dependence, while the electron (e-) flux exhibits a markedly different rigidity dependence. 
In the absolute-rigidity range below 60 GV, the p/p, p/e+ and p/e+ flux ratios each reach a maximum, while in the range 60-500 GV these ratios unexpectedly show no rigidity dependence.
Antiproton flux and flux ratio data, as well as the other published data from AMS-02, Pamela and other cosmic ray mission are available online at the
ASDC-cosmic ray database.

The measured antiproton flux (red, left axis) compared to the proton flux (blue, left axis), the electron flux (purple, right axis), and the positron flux (green, right axis). All the fluxes are multiplied by |R|2.7. The fluxes show different behavior at low rigidities while at |R| above ~60 GV the functional behavior of the antiproton, proton, and positron fluxes are nearly identical and distinctly different from the electron flux. 
The error bars correspond to the quadratic sum of the statistical and systematic errors.  Further reading:
M Aguilar et al. (AMS Collaboration) Phys. Rev. Lett. 117, 2016, 091103.
(read more). 

    

  

 

ASDC activities for the European Researchers Night 2016 at ASI HQ

Hundreds of visitors, many children with their families among the other, attended to the 11th Edition of the "European Researchers' Night" on 30th September 2016 hosted in Italian Space Agency (ASI) Headquarters in Rome. This event every year promotes the scientific culture and its value for the society and economy and the potentialities that research professions can offer.
As usual, ASDC has been involved, with more than 20 researchers, in this event by proposing experiments, interactive exhibits and lectures.
 
The following experiments (in which ASI/ASDC are involved) have been proposed:
Herschel: guided by the experts people discovered visible and infrared light characteristics by means of thermometers placed along diffracted light (from visible to infrared) and a thermal camera (courtesy of FLIR) looking at them highlighted their infrared appearance.
Gaia mock-up: a laboratory proved optical bench helped in understanding the working principle of the BAM instrument that measures the fluctuations of telescopes base angle due to thermal dilation.
• 
Exoplanet transit method scale models: using common materials (such as also LEGO bricks) with a webcam and a free computer software we illustrated the technique used by the NASA Kepler exoplanet discoverer mission, also introducing the future ESA CHEOPS and PLATO 2.0 missions and the related ASDC contribution.
    
The missions
Planck, Fermi, Pamela, BeppoSAX, AMS-02, Gaia, AGILE, Herschel, Rosetta, Swift, and the CTA project were presented showing spacecraft models or mission/project information brochures and panels and comics
Astrophysics with data from space missions was presented in a public speech together with the description of the on-line data archives and analysis tools offered by ASDC to professional (but also amateur) astronomers.
Furthermore, a live streaming from AMS-02 Control Center at CERN has been broadcasted to show its activities and duties.

More info about the whole ASI event
here and here.   Here a photo gallery and a slideshow (read more and see videos here). 

 

 

 

Latest news from the Swift mission at ASDC

The Swift satellite, optimized to chase GRBs, has scheduling flexibility and response capabilities that have soon transformed the mission in a prime discovery tool for other types of astrophysical sources and research topics in time domain astronomy (TDA), carrying on guest observer and Target of Opportunity (ToO) multiwavelength observations (Gehrels & Cannizzo 2015, JHEAp, 7, 2). Swift is also providing coverage for gravitational wave alerts as well as for cosmic neutrino events. TDA is one of the most active and growing areas of research in astrophysics, being able to shed light on every aspect of this science with a different perspective. It focuses both on transient sources and sky surveys, the first usually involving catastrophic events, and the second involving variability studies an serendipitous discoveries. During the first 10 years of orbital operations Swift detected about 1000 GRBs and performed 6300 ToOs. In particular approximatively 11 percent of its observing time was dedicated to blazars, carrying out more than 12,000 observations of about 1600 different blazar targets (Giommi 2015, JHEAp, 7, 173).
       
The ASDC is involved in the Swift mission since its launch, both on the more technological activities (responsibility of the XRT Data Analysis Software, hosting one of the three official data archives,
on-line XRT and UVOT data analysis tools and quick look data, source catalogs, burst advocate activity, and other activities) and the multiwavelength/multimessenger observing campaigns and researches. As an example, deconvolved Swift XRT X-ray spectra and best fit spectral parameters are now available through the ASDC SED builder tool, while the Swift UVOT interactive analysis pipeline has been updated and a systematic archival phometric processing of all UVOT images including blazar-type sources (representing a further TDA project) is in completion.      
Some
r
ecent examples of Swift observations and studies developed with an important contribution of the ASDC team, both on the analysis and scientific interpretation, are the following.
         
 
• The NuSTAR-Swift and multiwavelength campaign on the nearby GeV-TeV blazar Mkn 421 (Balokovic et al. 2016, ApJ, 819, 156; and Aleksic et al. 2015, A&A, 576, A126), with 33 dedicated observations by UVOT and XRT in the period January-March 2013 and complementing the rich multiwavelenght data and the detailed NuSTAR time-domain observations yielded in the 3-79 keV band.
        

 • The Swift monitor observations of the peculiar blazar OJ 287 performed in the frame of a winter-2015/2016 multiwavelength campaign. This Swift TDA experiment led by S. Ciprini (ASDC/INFN) provided detailed UVOT and XRT data able to corroborate or disagree with the debated scenario of optical quasi-periodicity driven by a binary system of two inspiralling supermassive black holes (SMBHs) with <0.1pc separation. Optical outbursts are predictable using Post-Newtonian theory and numerical computations and the light curve clocking can be used to test General Relativity features and model system parameters (Valtonen et al. 2016, ApJ, 819, L37; and ASI newsINAF newsAAS news). The Swift data analysis was managed by M. Perri (ASDC/INAF) and F. Verrecchia (ASDC/INAF).
              
 • The Fermi-Swift and multiwavelength analysis of the possible long-term oscillation in the GeV-TeV blazar PG 1553+113 (
Ackermann et al. 2015, ApJ, 813, L41; and ASDC news, ASI news, INAF newsNASA news). The data analysis and scientific research were led by S. Cutini (ASDC/INFN) and S. Ciprini (ASDC/INFN) in the frame of the Fermi mission. The Swift XRT and UVOT analysis of all the available data was managed by M. Perri (ASDC/INAF). A regular long-term monitor of the source with Swift is currently ongoing from the end of 2015 in the frame of a MAGIC monitor campaign. 
      
 
Swift contribution to the multiwavelength campaign on the new GeV-TeV blazar H 1722+119 (
Ahnen et al. 2016, MNRAS, 459, 3271
). The three Swift observations on 2008 and 2013 show an interesting break in the optical-UV energy band of the SED that also prevents a smooth connection with the X-ray band. In this case the UVOT data requested a particularly careful analysis that  was managed by F. Verrecchia (ASDC/INAF).
      
 • The Swift localization observations and mutiwavelength follow-up of the gravitational-wave burst GW150914 (Evans et al. 2016, MNRAS, 462, 1591; and Abbott et al. 2016, ApJ, 826, L13).  (read more). 

  

   

Open Universe


“Open Universe” is an initiative proposed by Italy  and approved in June 2016 by the United Nations Committee On the Peaceful Uses of Outer Space (COPUOS) at its 59th meeting in Vienna. The main objective of “Open Universe” is to stimulate a dramatic increase in the usability of space science data, extending the potential of scientific discovery to new participants in all parts of the world and empowering global educational services.
This will be achieved by ensuring that space science data gradually becomes more “transparent” to the citizens, that is openly available and usable by the widest possible community, from professional space scientists (several thousands of individuals) to citizen scientists (of the order of millions) to the common citizens generally interested in space science (potentially hundreds of millions).

  
The level of services delivered by the current generation of space science data archives is very heterogeneous, ranging from basic services to a restricted number of researchers, to open access web-based services offering “science-ready” products, that is high-level calibrated data that can be used in a publication without further analysis by scientists with suitable knowledge.
“Open Universe” will implement a method of measuring the transparency of the data available from current space science data archives, and urge the data producers to increase their present efforts so as to extend the usability of space science data to the non-professional community. The extra cost of reaching the level of adequate transparency (“web-ready” data products) is almost certainly a very small fraction (likely less than 1%) of the funding level necessary to produce and archive space science data. The benefits of such a cultural step are potentially enormous.
The first public event within the “Open Universe” Initiative is a workshop, to be co-organized by the Italian Space Agency (ASI) and the United Nations Office of Outer Space Affairs (UNOOSA), to bring together the various components of the community potentially interested in space science data.  

More information is available in the following documents:
Open Universe presentation
Open Universe initiative document    (read more).