R. Turolla
A5025652460- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- High-pressure geophysics and materials
- Astrophysics and Cosmic Phenomena
- Geophysics and Sensor Technology
- Geophysics and Gravity Measurements
- Astronomical Observations and Instrumentation
- Solar and Space Plasma Dynamics
- Stellar, planetary, and galactic studies
- Mechanics and Biomechanics Studies
- Cosmology and Gravitation Theories
- Particle Accelerators and Free-Electron Lasers
- Astro and Planetary Science
- Particle Detector Development and Performance
- Astrophysics and Star Formation Studies
- Radio Astronomy Observations and Technology
- Galaxies: Formation, Evolution, Phenomena
- Superconducting Materials and Applications
- Magnetic confinement fusion research
- Fluid Dynamics and Turbulent Flows
- Nuclear Physics and Applications
- Adaptive optics and wavefront sensing
- Atomic and Subatomic Physics Research
- Particle accelerators and beam dynamics
University College London
2015-2024
University of Padua
2015-2024
Institute for Space Astrophysics and Planetology
2014-2024
Marshall Space Flight Center
2011-2024
Roma Tre University
2022
Istituto Nazionale di Fisica Nucleare
2000-2018
American Society for Radiation Oncology
2018
Technical University of Denmark
2016
Istituto Nazionale di Fisica Nucleare, Roma Tor Vergata
2016
University of Geneva
2016
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...
Soft gamma repeaters and anomalous x-ray pulsars form a rapidly increasing group of sources exhibiting sporadic emission short bursts. They are believed to be magnetars, i.e. neutron stars powered by extreme magnetic fields, B~10^{14}-10^{15} Gauss. We report on soft repeater with low field, SGR 0418+5729, recently detected after it emitted bursts similar those magnetars. X-ray observations show that its dipolar field cannot greater than 7.5x10^{12} Gauss, well in the range ordinary radio...
Launched on 2021 December 9, the Imaging X-ray Polarimetry Explorer (IXPE) is a NASA Small Mission in collaboration with Italian Space Agency (ASI). The mission will open new window of investigation—imaging x-ray polarimetry. observatory features three identical telescopes, each consisting mirror module assembly polarization-sensitive imaging detector at focus. A coilable boom, deployed orbit, provides necessary 4-m focal length. utilizes three-axis-stabilized spacecraft, which services such...
XIPE, the X-ray Imaging Polarimetry Explorer, is a mission dedicated to Astronomy. At time of writing XIPE in competitive phase A as fourth medium size ESA (M4). It promises reopen polarimetry window high energy Astrophysics after more than 4 decades thanks detector that efficiently exploits photoelectric effect and optics with large effective area. uniqueness time-spectrally-spatially- resolved breakthrough astrophysics fundamental physics. Indeed payload consists three Gas Pixel Detectors...
Abstract We discovered 2.8 s pulsations in the X-ray emission of ultraluminous source (ULX) M51 ULX-7 within UNSEeN project, which was designed to hunt for new pulsating ULXs (PULXs) with XMM-Newton. The pulse shape is sinusoidal, and large variations its amplitude were observed even single exposures (pulsed fraction from less than 5% 20%). Source variable, generally at an luminosity between 10 39 40 erg −1 , located outskirts spiral galaxy M51a a distance 8.6 Mpc. According our analysis,...
We report on the long term X-ray monitoring with Swift, RXTE, Suzaku, Chandra and XMM-Newton of outburst newly discovered magnetar Swift J1822.3-1606 (SGR 1822-1606), from first observations soon after detection short bursts which led to its discovery, through stages decay (covering time-span July 2011, until end April 2012). also archival ROSAT witnessed source during likely quiescent state, upper limits J1822.3-1606's radio-pulsed optical emission outburst, Green Bank Telescope (GBT) Gran...
The 'Magnificent Seven' (M7) are a group of radio-quiet isolated neutron stars discovered in the soft X-rays through their purely thermal surface emission. Owing to large inferred magnetic fields (B ≈ 1013 G), radiation from these sources is expected be substantially polarized, independently mechanism actually responsible for A observed polarization degree (PD) is, however, only if quantum-electrodynamic (QED) effects present magnetized vacuum around star. detection strong linearly polarized...
We report on the discovery of a new member magnetar class, SGR J1935+2154, and its timing spectral properties measured by an extensive observational campaign carried out between 2014 July 2015 March with Chandra XMM–Newton (11 pointings). discovered spin period J1935+2154 through detection coherent pulsations at about 3.24 s. The is slowing down rate |$\dot{P} = 1.43(1)\times 10^{-11}$| s s−1 decreasing trend due to negative |$\ddot{P}$| −3.5(7) × 10−19 s−2. This implies surface dipolar...
The center of our Galaxy hosts a supermassive black hole, Sagittarius (Sgr) A*. Young, massive stars within 0.5 pc Sgr A* are evidence an episode intense star formation near the hole few million years ago, which might have left behind young neutron traveling deep into A*'s gravitational potential. On 2013 April 25, short X-ray burst was observed from direction Galactic center. With series observations with Chandra and Swift satellites, we pinpoint associated magnetar at angular distance 2.4...
Abstract Particle acceleration mechanisms in supermassive black hole jets, such as shock acceleration, magnetic reconnection, and turbulence, are expected to have observable signatures the multiwavelength polarization properties of blazars. The recent launch Imaging X-Ray Polarimetry Explorer (IXPE) enables us, for first time, use X-ray band (2–8 keV) probe jet synchrotron emission high-synchrotron-peaked BL Lac objects (HSPs). We report discovery linear (degree Π x = 15% ± 2% electric...
We report on the first detection of linearly polarized x-ray emission from an ultra-magnetized neutron star with Imaging X-ray Polarimetry Explorer (IXPE). The IXPE 35 observations anomalous pulsar 4U 0142+61 reveal a linear polarization degree $(12\pm 1)\%$ throughout 2--8 keV band. detect substantial variation energy: is $(14\pm at 2--4 and $(41\pm 7)\%$ 5.5--8 keV, while it drops below instrumental sensitivity around 4--5 where angle swings by $\sim 90^\circ$. give us completely new...
We report on a comprehensive analysis of simultaneous X-ray polarimetric and spectral data the bright atoll source GX 9+9 with Imaging Polarimetry Explorer (IXPE) NuSTAR. The is significantly polarized in 4--8 keV band, degree $2.2\% \pm 0.5\%$ (uncertainty at 68% confidence level). NuSTAR broad-band spectrum clearly shows an iron line, well described by model including thermal disk emission, Comptonized component, reflection. From spectro-polarimetric fit, we obtain upper limit to...
Abstract The launch of the Imaging X-ray Polarimetry Explorer (IXPE) on 2021 December 9 has opened a new window in astronomy. We report here results first IXPE observation weakly magnetized neutron star, GS 1826−238, performed 2022 March 29–31 when source was high soft state. An upper limit (99.73% confidence level) 1.3% for linear polarization degree is obtained over 2–8 keV energy range. Coordinated INTEGRAL and NICER observations were carried out simultaneously with IXPE. spectral...
Abstract We present the first X-ray polarimetric study of dipping accreting neutron star 4U 1624−49 with Imaging Polarimetry Explorer. report a detection polarization in nondip time intervals confidence level 99.99%. find an average degree (PD) 3.1% ± 0.7% and angle 81° 6° east north 2–8 keV band. upper limit on PD 22% during dips 95% confidence. The increases energy, reaching from 3.0% 0.9% 4–6 band to 6% 2% 6–8 This indicates likely arises Comptonization. high observed is unlikely be...
The anomalous X-ray pulsars and soft gamma-repeaters are peculiar high-energy sources believed to host a magnetar, i.e. an ultra-magnetized neutron star. Their persistent, emission (~1-10 keV)is usually modeled by the superposition of blackbody power-law tail. It has been suggested that this spectrum forms as thermal photons emitted star surface traverse magnetosphere. Magnetar magnetospheres likely different from those ordinary radio-pulsars, since external magnetic field may acquire...
We present a systematic fit of model resonant cyclotron scattering (RCS) to the X-ray data 10 magnetars, including canonical and transient anomalous pulsars (AXPs) soft gamma repeaters (SGRs). In this scenario, nonthermal magnetar spectra in X-rays (i.e., below ~10 keV) result from thermal surface emission by hot magnetospheric plasma. find that can successfully account for while using same number free parameters as commonly used empirical blackbody plus power-law model. However, RCS alone...
On 2009 January 22 numerous strong bursts were detected from the anomalous X-ray pulsar 1E 1547.0-5408. Swift/XRT and XMM-Newton/EPIC observations carried out in following two weeks led to discovery of three rings centered on this source. The ring radii increased with time expansion law expected for a short impulse X-rays scattered by dust clouds. Assuming different models composition grain size distribution, we fit intensity decay each as function at energies, obtaining tight constrains...