A5034427738- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- SAS software applications and methods
- Astronomy and Astrophysical Research
- Pulsars and Gravitational Waves Research
- Radio Astronomy Observations and Technology
- Particle Detector Development and Performance
- Particle Accelerators and Free-Electron Lasers
- Dark Matter and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Mechanics and Biomechanics Studies
- Astro and Planetary Science
- High-pressure geophysics and materials
- Neutrino Physics Research
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Gyrotron and Vacuum Electronics Research
- Nuclear Physics and Applications
- Inertial Sensor and Navigation
- Calibration and Measurement Techniques
- Microbial Metabolites in Food Biotechnology
- Planetary Science and Exploration
Agenzia Spaziale Italiana
2015-2024
Astronomical Observatory of Rome
2015-2024
National Institute for Astrophysics
2015-2024
Institute for Space Astrophysics and Planetology
2023-2024
Geophysical Laboratory
2024
Boston University
2024
Czech Academy of Sciences, Astronomical Institute
2024
Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca
2024
Space (Italy)
2018-2023
University of Pisa
2023
The Nuclear Spectroscopic Telescope Array (NuSTAR) mission, launched on 2012 June 13, is the first focusing high-energy X-ray telescope in orbit. NuSTAR operates band from 3 to 79 keV, extending sensitivity of far beyond ∼10 keV cutoff achieved by all previous satellites. inherently low background associated with concentrating light enables probe hard sky a more than 100-fold improvement over collimated or coded mask instruments that have operated this bandpass. Using its unprecedented...
We present a homogeneous X-ray analysis of all 318 gamma-ray bursts detected by the telescope (XRT) on Swift satellite up to 2008 July 23; this represents largest sample GRB data published date. In Sections 2–3, we detail methods which Swift-XRT team has developed produce enhanced positions, light curves, hardness ratios and spectra presented in paper. Software using these continues create such products for new GRBs observed Swift-XRT. also web-based tools allowing users any object XRT, not...
Context.Swift data are revolutionising our understanding of Gamma Ray Bursts. Since bursts fade rapidly, it is desirable to create and disseminate accurate light curves rapidly.
Gamma-ray burst (GRB) afterglows have provided important clues to the nature of these massive explosive events, providing direct information on nearby environment and indirect central engine that powers burst. We report discovery two bright x-ray flares in GRB afterglows, including a giant flare comparable total energy itself, each peaking minutes after These strong, rapid imply engines bursts long periods activity, with strong internal shocks continuing for hundreds seconds gamma-ray...
Spinning up an extragalactic neutron star Ultraluminous x-ray sources (ULXs) are strange objects in other galaxies that cannot be explained by conventional accretion onto stellar-mass objects. This has led to exotic interpretations, such as the long-sought intermediate-mass black holes. Israel et al. observed a ULX nearby galaxy NGC 5907 and found it is instead star. The spinning accreting material so fast its spin period quickly accelerating. only way can consume enough explain these...
We present a new catalogue of blazars based on multi-frequency surveys and an extensive review the literature. Blazars are classified as BL Lacertae objects, flat spectrum radio quasars or uncertain/transitional type. Each object is identified by root name, coded BZB, BZQ BZU for these three subclasses respectively, its coordinates. This being built tool useful identification extragalactic sources that will be detected future experiments X gamma-ray astronomy, like Swift, AGILE, Fermi-GLAST...
We present the calibration of Nuclear Spectroscopic Telescope Array (NuSTAR) X-ray satellite. used Crab as primary effective area calibrator and constructed a piece-wise linear spline function to modify vignetting response. The achieved residuals for all off-axis angles energies, compared assumed spectrum, are typically better than ±2% up 40 keV 5%–10% above due limited counting statistics. An empirical adjustment theoretical two-dimensional point-spread (PSF) was found using several strong...
With the first direct detection of merging black holes in 2015, era gravitational wave (GW) astrophysics began. A complete picture compact object mergers, however, requires an electromagnetic (EM) counterpart. We report ultraviolet (UV) and X-ray observations by Swift Nuclear Spectroscopic Telescope ARray (NuSTAR) EM counterpart binary neutron star merger GW170817. The bright, rapidly fading emission indicates a high mass ($\approx0.03$ solar masses) wind-driven outflow with moderate...
While X-ray Spectroscopy, Timing and Imaging have improved verymuch since 1962, when the first astronomical non-solar source was discovered, especially with launch of Newton/X-ray Multi-Mirror Mission, Rossi/X-ray Explorer Chandra/Advanced Astrophysics Facility, progress polarimetry has been meager. This is in part due to lack sensitive polarization detectors, fate approved missions because celestial sources appeared less polarized than expected. Only one positive measurement available until...
A black hole x-ray binary (XRB) system forms when gas is stripped from a normal star and accretes onto hole, which heats the sufficiently to emit x-rays. We report polarimetric observation of XRB Cygnus X-1 using Imaging Polarimetry Explorer. The electric field position angle aligns with outflowing jet, indicating that jet launched inner emitting region. polarization degree (4.01+-0.20)% at 2 8 kiloelectronvolts, implying accretion disk viewed closer edge-on than orbit. observations reveal...
We report the discovery of unusually bright long-duration gamma-ray burst (GRB), GRB 221009A, as observed by Neil Gehrels Swift Observatory (Swift), Monitor All-sky X-ray Image (MAXI), and Neutron Star Interior Composition Explorer Mission (NICER). This energetic was located relatively nearby (z = 0.151), allowing for sustained observations afterglow. The large luminosity low Galactic latitude (b 4.3 degrees) make 221009A a powerful probe dust in Milky Way. Using echo tomography we map...
Abstract Most of the light from blazars, active galactic nuclei with jets magnetized plasma that point nearly along line sight, is produced by high-energy particles, up to around 1 TeV. Although are known be ultimately powered a supermassive black hole, how particles accelerated such high energies has been an unanswered question. The process must related magnetic field, which can probed observations polarization jets. Measurements radio optical polarization—the only range available until...
ABSTRACT We present an X-ray spectropolarimetric analysis of the bright Seyfert galaxy NGC 4151. The source has been observed with Imaging Polarimetry Explorer (IXPE) for 700 ks, complemented simultaneous XMM–Newton (50 ks) and NuSTAR (100 pointings. A polarization degree Π = 4.9 ± 1.1 per cent angle Ψ 86° 7° east north (68 confidence level) are measured in 2–8 keV energy range. shows that could be entirely due to reflection. Given low reflection flux IXPE band, this requires, however, a...
Abstract We report on an observational campaign the bright black hole (BH) X-ray binary Swift J1727.8–1613 centered around five observations by Imaging Polarimetry Explorer. These track for first time evolution of polarization a BH across hard to soft state transition. The 2–8 keV degree decreased from ∼4% ∼3% observations, but angle remained oriented in north–south direction throughout. Based with Australia Telescope Compact Array, we find that intrinsic 7.25 GHz radio aligns polarization....
We report the results of a new analysis 13 wide band BeppoSAX observations BL Lac object Mkn 421. The data from LECS, MECS and PDS, covering an energy interval 0.1 to over 100 keV, have been used study spectral variability this source. show that distributions in different luminosity states can be fitted very well by log-parabolic law , which provides good estimates flux synchrotron peak SED. In first four short 1997 421 was characterized stable shape, with average values independently source...
We present observations of the early X-ray emission for a sample 40 gamma-ray bursts (GRBs) obtained using Swift satellite which narrow-field instruments were pointed at burst within 10 minutes trigger. Using data from Burst Alert and X-Ray Telescopes, we show that light curve can be well described by an exponential relaxes into power law, often with flares superimposed. The transition time between law provides physically defined timescale duration. In most breaks to shallower decay first...