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ASDC Newsletter #11


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Latest news from the NuSTAR mission

• NuSTAR new major data release
Starting from March 31, 2015 the 6th release of NuSTAR scientific data archive (Data Release 6, DR6) is available at the ASDC and HEASARC. This is by far the largest data release. It contains 679 new data sets observed up to July 31, 2014. All the NuSTAR public data at ASDC are fully integrated in the ASDC Multi-Mission Interactive Archive (MMIA). Through the MMIA the user can perform on-line analysis of all NuSTAR public observations, without the need to download any software, including the extraction of high-level scientific products (cleaned event files, sky images, energy spectra, light-curves, ARFs and RMFs).
 
Fiona Harrison receives the 2015 Bruno Rossi Prize
We are pleased to report that the 2015 Bruno Rossi Prize of the High Energy Astrophysics Division (HEAD) of the American Astronomical Society has been awarded to the NuSTAR Principal Investigator Fiona Harrison for her "groundbreaking work on supernova remnants, neutron stars and black holes enabled by NuSTAR, the first satellite to focus X-rays at energies above 10 kiloelectron volts (keV)." The citation for the Rossi Prize, the top prize in high-energy astrophysics, notes that Harrison's "assembly and leadership of the extraordinary NuSTAR team has opened a new window on the Universe." "The exciting scientific results from NuSTAR are the culmination of close to two decades of work by a talented and dedicated team," said Harrison. "It is a privilege to work with them, and an honor to be recognized through the Rossi Prize." This is the fifth time that a space mission for which the ASDC plays an important role has been awarded a Rossi Prize, after BeppoSAX in 1998, Swift in 2007, Fermi in 2011 and AGILE in 2012.

• The Mission

NuSTAR (Nuclear Spectroscopic Telescope Array) was launched in June 2012 under NASA's Small Explorer program. The primary science objectives are the study of the hottest, densest and most energetic phenomena in the universe, including the physics of massive black holes and collapsed stars, the explosion dynamics and nucleosynthesis in supernovae, and the particle acceleration in relativistic jets in Active Galactic Nuclei. The Italian participation to NuSTAR includes a) the provision of the Malindi ground station (ASI), b) the support of the ASI Science Data Center (ASDC), which has developed and maintains the NuSTARDAS data analysis software package and hosts an official mirror of the NuSTAR scientific data archive, and c) a team of scientists of the Istituto Nazionale di Astrofisica (INAF) and of Italian Universities to collaborate on the primary scientific mission goals.

For more details on NuSTAR see: nustar.asdc.asi.it      www.nustar.caltech.edu      heasarc.gsfc.nasa.gov/docs/nustar/    

 

 

First Gaia BP/RP deblended spectra

Gaia is the ESA’s cornerstone space mission aimed at global astrometry at the microarcsecond level. Gaia was launched on December 19th, 2014, during its 5-year operational lifetime the satellite will observe more than 1 billion of sources. For each source, Gaia provides low resolution spectra through two different prisms: "blue" channel (300-660 nm), and "red" channel (650-1000 nm). The dispersion of the prisms ranges from 3 to 29 nm/pixel for BP and from 7 to 15 nm/pixel for RP. Most of the data are sent to the ground as 1D spectra.
Spectrophotometry will compensate for chromaticity shift of the star’s centroids, and will beused to derive astrophysical parameters ([M/H], T, logg, Av) for a not negligible fraction of the Milky Way stars. Considering the along-scan dispersion, the superimposition of two field of views, and the large stellar density in many regions of the sky, overlapping of stellar spectra will often occur. In order to obtain accurate values for the astrophysical parameters and to compensate for the chromaticity shift, the BP/RP flux extraction of blended transits (i.e. observation of overlapped stellar and non-stellar spectra) is mandatory: an error in the extraction could involve a variation of the spectral morphology and produce large errors in the estimation of parameters and also affect the astrometric performances. 
ASDC, in collaboration with the Astronomical Observatory of Rome (INAF-OAR), is involved in DPAC-CU5, the coordination unit responsible for the analysis of the Gaia spectrophotometric data, in the development of the software for disentangling the blended transits. The deblending software full deployment at the Cambridge Gaia Data Processing Centre (IoA, 
gaia.ac.uk/gaia-uk/ioa-cambridge/dpci) is foreseen at the end of 2015,. Testing on real Gaia data has already started. As a testbed, a set of known bright double stars has been processed. Fig.1 shows the output of the code applied on the BP/RP spectra of the double star "HD 270801", i. e. the first Gaia BP/RP deblended object (read more).
A full and detailed description of the Gaia mission is available at:
gaia.asdc.asi.it ,   www.cosmos.esa.int/web/gaia

  

   

The Gaia-SPSS  Archive at ASDC

Gaia is the ESA’s cornerstone space mission aimed at global astrometry at the microarcsecond level. During its 5-years of operational lifetime, the satellite (launched on December 19th, 2014) will observe more than 1 billion sources. Gaia needs external data to fix the zero-point of the magnitude system and radial velocities, and to calibrate the classification/parametrization algorithms.
Given the complexity of both the Gaia focal plane and observation strategy, the “simple'” problem of calibrating the integrated BP/RP and G-band magnitudes and the low resolution BP/RP spectra flux turns into a very delicate and complex issue. The calibration model (developed by CU5-DU14, as part of the international consortium for Gaia data reduction) requires a carefully selected set of 200 SPSS (Spectro-Photometric Standard Stars) flux tables with a nominal accuracy of a few %, with respect to Vega. The goal of CU5-DU13 is to build the Gaia SPSS grid with accurate flux calibrated energy distributions through ground-based observations and careful data reduction procedures, in order to allow the conversion of Gaia instrumental wide band photometry and spectrophotometry into physical units.
The amount and complexity of SPSS data require a careful data organization: the data must be easily available to both the DPAC unit in charge of the SPSS flux tables production and the entire astronomical community alongside the foreseen Gaia data releases. ASDC, in collaboration with the CU5-DU13 team, is responsible of the management and preservation of these fundamental Gaia Ancillary data. In this framework we are building the Gaia-SPSS archive and database. The SPSS archive and database is already operational at ASDC and daily updated by the CU5-DU13 team. A public version of this archive is foreseen alongside the first Gaia data release (mid-2016).
The Gaia SPSS grid will be a new, unprecedented catalogue of spectrophotometric standard stars characterized by high precision and accuracy, full sky coverage and with stars spanning a wide range of spectral types.
Besides the absolute calibration of Gaia spectrophotometric data, it will be useful also for the absolute calibration of other spectroscopic ground-based surveys like the dark energy surveys that require a high-quality calibration of spectroscopic fluxes (read more). A complete and detailed description of the Gaia mission is available at: 
gaia.asdc.asi.it ,   www.cosmos.esa.int/web/gaia.

 

   

Planck 2015 data release: cosmic reionisation and first stars

On February 5, 2015, the Planck Collaboration released a new set of data products and scientific papers. The new results are based on all data collected throughout the mission, between 2009 and 2013. In addition to intensity maps at all nine frequency bands observed by Planck, polarization maps at four frequencies (30, 44, 70, and 353 GHz) are being released.
Planck polarization data not only provides an independent confirmation of the basic cosmological picture drawn using CMB intensity from both 2013 and 2015 maps. In fact, studying the properties of CMB polarization at large angular scales, Planck scientists concluded that the reionisation of the Universe due to first stars happened 550 million years after the Big Bang, more than 100 million years later than previously thought. So, the Dark Ages of the Universe ended later. This is of fundamental importance because that 100 million years difference is significantly reducing the tension between CMB results and current knowledge of first stars and early galaxies.
Polarization doesn't mean only reionisation. Indeed, by analysing polarized maps at different frequencies, Planck scientists obtained new insights on the properties of the Galactic magnetic field. Planck's new findings include also neutrino physics and dark matter annihilation.
The whole list of Planck scientific results is much longer, as described in the papers that are available on
ESA website. Planck public data products can be accessed through the Planck Legacy Archive. Additional results and products will be released in the forthcoming weeks.
For more information, see: 
ESA press release INAF website (in Italian).
Planck
ERCSC and PCCS source catalogues are available on the ASDC website.

 

 

Second Release of the Swift UVOT image interactive analysis tool

A new version of the ASDC interactive imaging tool dedicated to the Swift Ultra Violet-Optical Telescope (UVOT) images archive has been released in January 2015. The first version of this service was presented in 2012 as one of the ASDC imaging tools to allow UVOT users to preview images in the public archive or of a new observation, and to obtain a flux estimate of a source of interest at a chosen sky position.
UVOT, one of the three instruments on-board the very successful NASA's Swift mission, launched in November 2004, can produce images in 6 optical/UV filters (V, B, U, UVW1, UVM2, UVW2, with central wavelength from about 547 nm to about 193 nm). The ASI Science Data Center hosts one of the official Swift data archive, whose data are all immediately public from the Quick Look Data Archive or the Multi-Mission Interactive Archive web pages: swift.asdc.asi.it/cgi-bin/ql/ql www.asdc.asi.it/mmia/.
The UVOT interactive tool can be accessed by clicking on the "UVOT On-line Analysis" in the output table of the interactive archive. The tool has been adapted to the new interactive window layout developed for AGILE-GRID and applied to the XRT interactive analysis tool in recent years, which includes the managing of more visualization parameters, plot recentering and improved catalog overplot options.
A faster processing procedure has been also developed, together with a new interactive "user defined" analysis, performing an aperture photometry at the position of each detected source. In addition this release comes after two pevious updates in 2013 and 2014, which introduced new magnitude dereddening (Schlafly et al. 2011), the use of an updated calibration version, the possibility to analyze the longest exposure slice only and other features
(read more).

 

 

Four-year Fermi-LAT source (3FGL) and AGN (3LAC) catalogs: interactive tables and data products at ASDC

The third Fermi Large Area Telescope (LAT) source catalog (3FGL, including 3033 sources above 4 sigma significance in the 100MeV-300GeV energy range) has been published based on the first four years of science data from the Fermi Gamma-ray Space Telescope mission. The 3FGL source catalog is the deepest yet in this energy range and incorporates twice as much data with respect to the 2FGL catalog as well as a number of analysis improvements. These include improved calibration at the event reconstruction level, an updated model for Galactic diffuse gamma-ray emission, a refined procedure for source detection, and improved methods for associating LAT sources with potential counterparts at other wavelengths. The Fermi Team of ASDC participated to comparison analysis and review of the 3FGL catalog with respect to the previous LAT catalogs.
The third catalog of active galactic nuclei (AGNs) detected by the Fermi LAT (the Third LAT AGN Catalog, 3LAC) has also been prepared with the co-leadership of the Fermi Team at ASDC. The 3LAC includes 1591 blazars and other AGNs located at high Galactic latitudes (|b|>10deg). Additional 182 associations with blazars are reported at (|b|<10 deg). About half of the newly detected gamma-ray blazars are of unknown type, i.e., they lack spectroscopic information of sufficient quality to determine the strength their emission lines. Based on their gamma-ray spectral properties, the classified sources are evenly split between Flat-Spectrum Radio Quasars (FSRQs) and BL Lac objects. The 3LAC catalog benefits of source-association software, multifrequency SED tools, and software for source classification and population studies that helped in build the catalog and in give a multifrequency characterization of each source. This has made possible thanks also to the capabilities of the ASDC SED Builder tool, through an international cooperative effort which saw the participation of 20 scientists and students (read more).

Interactive tables for the 3FGL and 3LAC catalogs are available at: 
www.asdc.asi.it/fermi3fgl/www.asdc.asi.it/fermi3lac/fermi.gsfc.nasa.gov/ssc/data/access/lat/4yr_catalog/ .

  

     

Latest news from the AGILE Data Center

On January 19, 2015 at 05:49:25 UTC the AGILE satellite successfully completed its 40.000th pass over the ASI Malindi Ground Station.
Launched April 23, 2007 in low Earth orbit, AGILE is working nominally after almost 8 years of orbital operations. The Italian satellite continues its exploration of the high-energy Universe, also giving a crucial contribution to the study of extreme Terrestrial atmospheric events (TGFs).
All AGILE data are regularly received and processed at the AGILE Data Center at ASDC, where the public archive now contains all observations from December 1, 2007 up to November 30, 2013 (from Cycle-1 to Cycle-6). The data are available from the ASDC Multimission Archive webpage for the AGILE Mission.
A successful test of a new on-board AGILE software configuration was recently completed. With the new configuration, AGILE observations of high-energy phenomena of Terrestrial origin at sub-millisecond timescales will be greatly enhanced during the coming months of operations.

 

      

The ASDC Bibliography Tool

The ASDC developed and operates a digital archive of literature produced by its staff.  This archive, and the associated software, is available to all ASDC users from the Center main website. It contains scientific and technical papers (refereed and non-refereed), which are associated to space missions or specific projects, or simply produced in collaboration with colleagues of other institutions or organizations. This tool is for public utility, and it is committed to all those who are interested in ASDC publications produced from its establishment in November 2000 to today. The tool can be accessed from the main ASDC website by clicking on the "ASDC Bibliography tool" icon or directly by following this URL: publications.asdc.asi.it/overview
A number of pages dedicated to statistics are available and can be viewed as a dashboard to explore the bibliographic information. All the charts are navigable, and users can interact with the charts through refined selections. The tool offers statistics sections dedicated to Journals, Missions and Authors (read more).

 

  

 

10 years of Swift conference in Rome

A meeting celebrating the 10 years of Swift mission (launched on November 20, 2004) and successes in the knowledge of the high-energy transient Universe was held in Rome in December 2014. Swift has unveiled many of the secrets of long and short GRBs and has observed and contributed significantly to our understanding of AGNs, supernovae, pulsars, microquasars, novae, variable stars, comets, and much more, taking advantage of its multi-wavelength instrumentation and fast scheduling capabilities, making it the most versatile high-energy mission ever flown.
The future prospects of time domain astrophysics, which could be addressed in the extended Swift mission were also reviewed during this conference, in addition to new approaches and ideas for non-conventional uses of the spacecraft. The conference has seen the participation of about 240 scientists, with a program containing 84 oral talks and 110 posters. The Swift mission
has a 2 more years of guaranteed full funding plus a possible extension to 2017 and 2018. More bursts, explosions, flashes, eruptions, mergers, glitches, flares, ejections, burps, breakouts, precursors and collisions observed by Swift are expected (read more).