Conveners
Direct hard-X-ray and γ-ray measurements
- John Tomsick (Space Sciences Laboratory / University of California, Berkeley)
Direct hard-X-ray and γ-ray measurements
- Sara Cutini (INFN sezione Perugia)
Direct hard-X-ray and γ-ray measurements
- Enrico Costa
Direct hard-X-ray and γ-ray measurements
- Elisabetta Cavazzuti
The Imaging X-ray Polarimetry Explorer is a NASA-ASI Small Explorer (SMEX) mission launched on 9$^{th}$ December 2021. It is equipped with three telescopes consisting on three light X-ray mirrors and three Detector Units at their focus. They host the polarization sensitive detectors designed, developed, tested and calibrated by the INAF and INFN teams. At the present time IXPE measured...
The enhanced X-ray Timing and Polarimetry mission (eXTP) is a flagship observatory for X-ray timing, spectroscopy and polarimetry developed by an International Consortium led by the Chinese Academy of Science, with a large participation of European institutions.
Thanks to its very large collecting area, good spectral resolution and unprecedented polarimetry capabilities, eXTP will explore...
In the Soft/Medium energy X-Ray band photoelectric focal plane polarimetry resulted, with IXPE, in a break-through increase of sensitivity. Both data and models advocate for an extension to the hard X ray range. At higher energies where gas based detectors are transparent scattering polarimetry is in practice the only viable method. I discuss the difference between collimated and focal plane...
X-rays are normally detected as single-hit energy deposits at their absorption point. A different technique, combining high efficiency photon to charge converters and fine-pitch, highly granular readout matrices of low-noise pixels with integrated smart amplifiers, can effectively track the low energy electrons resulting from the photon interaction, thus revealing details of the Compton...
The present generation of space-borne gamma-ray detectors have greatly improved our understanding of many astrophysical phenomena and have opened new opportunities for the investigation of the Universe. Data from the Fermi mission have demonstrated that the extreme processes that produce gravitational waves and accelerate neutrinos and cosmic rays also produce gamma rays. Multimessenger...
The Compton Spectrometer and Imager (COSI) is a NASA Small Explorer (SMEX) satellite mission in development with a planned launch in 2027. COSI operates as a Compton telescope in the 0.2-5 MeV gamma-ray bandpass, it has an instantaneous field of view of >25%-sky, and it obtains coverage the entire sky every day. COSI provides imaging, spectroscopy, and polarimetry of astrophysical sources,...
The ability to observe transient events with good angular and energy resolutions is currently lacking in MeV gamma-ray astrophysics.
The Galactic Explorer with a Coded Aperture Mask Compton Telescope (“GECCO”) will provide these capabilities thanks to the innovative use of a deployable coded aperture mask in combination with a Compton telescope mode.
For effective observation of transient...
The radiation produced by gamma-ray bursts (GRBs) is generated in highly relativistic jets. The nature of the central engines producing these jets, their physical composition, and the processes of energy dissipation and radiation in them, are still poorly understood, more than 50 years after the discovery of GRBs. Gamma-ray polarimetry is a powerful diagnostic of the high-energy physics...
The High Energy cosmic-Radiation Detection (HERD) facility has been proposed as one of the main experiments on board the China Space Station. Herd is scheduled to be installed around 2027, and to operate for at least 10 years. Its main stated scientific goals are the study of the cosmic ray spectrum and composition up to the ~PeV energy range, indirect dark matter detection, and all-sky...
HERMES (High Energy Rapid Modular Ensemble of Satellites) Pathfinder is a space-borne mission based on a constellation of six nano-satellites flying in a low-Earth orbit (LEO). The 3U CubeSats, to be launched mid-2024, host miniaturized instruments with a hybrid Silicon Drift Detector/GAGG:Ce scintillator photodetector system, sensitive to X-rays and gamma-rays in a large energy band (~3 keV...
Crystal Eye is a new concept of space-based telescope for the observation of 0.1-10 MeV
photons exploiting a new detection technique, which foresees enhanced localization
capability with respect to current instruments.
This is now possible thanks to the use of new materials and sensors.
The primary scientific goal is the detection of the electromagnetic signal of extreme
phenomena in the...
Serendipitously discovered by the BATSE mission in the nineties, Terrestrial Gamma-ray Flashes (TGFs) represent the most intense and energetic natural emission of gamma rays form our planet. TGFs consist of sub-millisecond bursts of gamma rays (energy up to one hundred MeV) generated during powerful thunderstorms by lightenings (average ignition altitude of about 10 km) and are in general...
We describe the design and the expected performances of the X/Gamma-ray Imaging Spectrometer (XGIS) which is a GRBs and transients monitor developed and studied for the THESEUS mission now in Phase 0 evaluation for the selection of ESA M7. XGIS is capable of covering an unprecedented wide energy band (2 keV - 10 MeV), with imaging capabilities and location accuracy <15 arcmin up to 150 keV...
We are going to present the prospects of the Xray-CMOS project (recently funded as Progetto di Ricerca di Rilevante Interesse Nazionale PRIN 2020), for the development of a TPC for large field of view X-ray polarimetry, in which no requirement is imposed to the orientation of the incoming X-ray with respect to the drift field. This could open a new window of observation on the Universe through...
When a beam of electrons/photons is aligned with the crystalline axes or planes in an oriented crystal, the probability of bremsstrahlung/pair production is strongly enhanced. This results in a shortening of the radiation length, X0, and thereby of the electromagnetic shower extent, as experimentally demonstrated recently by our team for tungsten [1] and high-Z scintillator (PWO) crystals [2]....
Future high-sensitivity observations of possible dark matter annihilation signals from dwarf galaxies will benefit from large-area (10-100 m$^2$ or greater) and high-angular resolution (~mrad) gamma ray observation. The angular resolution is necessary to further improve the signal-to-background for faint gamma signals. Large areas will allow for significant gains in candidate gamma events...
We present our study on the reconstruction of photo-electron (PE) tracks in Gas Pixel Detectors (GPDs) used for astrophysical X-ray polarimetry. The GPD exploits photo-electric effect to measure the polarization state of incident photons by reconstructing the properties of the track of emitted photo-electrons. The standard state-of-the-art algorithm developed by Imaging X-ray Polarimetry...
The Antarctic Demonstrator for the Advanced Particle-astrophysics Telescope (ADAPT) is a project to build a prototype telescope to detect low energy astrophysical gamma rays in the MeV energy range. The instrument will consist of four layers of a scintillating fiber tracker plus an active converter tracker made of CsI scintillating crystals read out by wavelength shifting (WLS) fibers. Both...
Terrestrial Gamma-ray Flashes (TGFs) are intense bursts of gamma rays that originate from the mid to upper levels of thunderstorms on Earth's atmosphere. Gamma-Flash is an Italian project supported by ASI devoted to the detection of such events and to the study of their correlation with lightning and with the emission of pulses of neutrons produced by photonuclear reactions in the atmosphere...
