Immacolata Donnarumma

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We present optical, X-ray, high energy (30 GeV) and very high energy (100 GeV; VHE) observations of the high-frequency peaked blazar Mrk 421 taken between 2008 May 24 and June 23. A high energy γ-ray signal was detected by AGILE with √ T S = 4.5 on June 9–15, with F (E > 100 MeV) = 42 +14 −12 × 10 −8 photons cm −2 s −1. This flaring state is brighter than(More)
We use a deep K AB ≤ 25 galaxy sample in the Hubble Deep Field South to trace the evolution of the cosmological stellar mass density from z ≃ 0.5 to z ≃ 3. We find clear evidence for a decrease of the average stellar mass density at high redshift, 2 ≤ z ≤ 3.2, that is 15 +25 −5 % of the local value, two times higher than what observed in the Hubble Deep(More)
We present a detailed analysis of the stellar mass content of galaxies up to z = 2.5 as obtained from the K20 spectrophotometric galaxy sample. We have applied and compared two different methods to estimate the stellar mass M * from broad–band photometry: a Maximal Age approach, where we maximize the age of the stellar population to obtain the maximal mass(More)
SuperAGILE is a coded mask experiment based on silicon microstrip detectors. It operates in the 15-45 keV nominal energy range, providing crossed one-dimensional images of the X-ray sky with an on-axis angular resolution of 6 arcmin, over a field of view in excess of 1 steradian. It was designed as the hard X-ray monitor of the AGILE space mission, a small(More)
The well-known Crab Nebula is at the center of the SN1054 supernova remnant. It consists of a rotationally powered pulsar interacting with a surrounding nebula through a relativistic particle wind. The emissions originating from the pulsar and nebula have been considered to be essentially stable. Here, we report the detection of strong gamma-ray (100(More)
High-time-resolution X-ray observations of compact objects provide direct access to strong-field gravity, to the equation of state of ultra-dense matter and to black hole masses and spins. A 10 m 2-class instrument in combination with good spectral resolution is required to exploit the relevant diagnostics and answer two of the fundamental questions of the(More)
  • A W Chen, F D 'ammando, M Villata, C M Raiteri, M Tavani, V Vittorini +26 others
  • 2008
Aims. We report the γ-ray activity from the intermediate BL Lac S5 0716+714 during observations acquired by the AGILE satellite in September and October 2007. These detections of activity were contemporaneous with a period of intense optical activity, which was monitored by GASP–WEBT. This simultaneous optical and γ-ray coverage allows us to study in detail(More)
The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final downselection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the(More)
Pulsars are known to power winds of relativistic particles that can produce bright nebulae by interacting with the surrounding medium. These pulsar wind nebulae are observed by their radio, optical, and x-ray emissions, and in some cases also at TeV (teraelectron volt) energies, but the lack of information in the gamma-ray band precludes drawing a(More)
  • F D 'ammando, G Pucella, C M Raiteri, M Villata, V Vittorini, S Vercellone +43 others
  • 2009
Context. We report the detection by the AGILE satellite of a rapid γ-ray flare from the source 1AGL J1511−0908, associated with the powerful γ-ray quasar PKS 1510−089, during a pointing centered on the Galactic Center region from 1 March to 30 March 2008. This source has been con-tinuosly monitored in the radio-to-optical bands by the GLAST-AGILE Support(More)