A5042005600- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Neutrino Physics Research
- Pulsars and Gravitational Waves Research
- Dark Matter and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Galaxies: Formation, Evolution, Phenomena
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Mechanics and Biomechanics Studies
- Particle Detector Development and Performance
- Gyrotron and Vacuum Electronics Research
- High-pressure geophysics and materials
- Astronomy and Astrophysical Research
- Cosmology and Gravitation Theories
- Particle accelerators and beam dynamics
- Particle physics theoretical and experimental studies
- Ionosphere and magnetosphere dynamics
- Stellar, planetary, and galactic studies
- Computational Physics and Python Applications
- Geophysics and Gravity Measurements
- Superconducting and THz Device Technology
- Astro and Planetary Science
Instituto de Astrofísica de Andalucía
2015-2024
Universitat de Barcelona
2024
Institute for Space Astrophysics and Planetology
2023-2024
Arcetri Astrophysical Observatory
2023-2024
Institut d'Estudis Espacials de Catalunya
2024
Max Planck Institute for Radio Astronomy
2006-2023
University of Turku
2007-2023
Durham University
2023
Astronomical Observatory of Rome
2021-2023
Turku Centre for Computer Science
2023
(Abridged) We have conducted a detailed investigation of the broad-band spectral properties \gamma-ray selected blazars Fermi LAT Bright AGN Sample (LBAS). By combining our accurately estimated gamma-ray spectra with Swift, radio, infra-red, optical and other hard X-ray/gamma-ray data, collected within three months LBAS data taking period, we were able to assemble high-quality quasi-simultaneous Spectral Energy Distributions (SED) for 48 blazars.The SED these sources is similar that...
The Cherenkov Telescope Array, CTA, will be the major global observatory for very high energy gamma-ray astronomy over next decade and beyond. scientific potential of CTA is extremely broad: from understanding role relativistic cosmic particles to search dark matter. an explorer extreme universe, probing environments immediate neighbourhood black holes voids on largest scales. Covering a huge range in photon 20 GeV 300 TeV, improve all aspects performance with respect current instruments....
We present results from monitoring the multi-waveband flux, linear polarization, and parsec-scale structure of quasar PKS 1510-089, concentrating on eight major gamma-ray flares that occurred during interval 2009.0-2009.5. The peaks were essentially simultaneous with maxima at optical wavelengths, although flux ratio two wavebands varied by an order magnitude. polarization vector rotated 720 degrees a 5-day period encompassing six these flares. This culminated in very bright, roughly 1 day,...
The binary neutron star merger event GW170817 was detected through both electromagnetic radiation and gravitational waves. Its afterglow emission may have been produced by either a narrow relativistic jet or an isotropic outflow. High-spatial-resolution measurements of the source size displacement can discriminate between these scenarios. We present very-long-baseline interferometry observations, performed 207.4 days after using global network 32 radio telescopes. apparent is constrained to...
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...
We provide an updated assessment of the power Cherenkov Telescope Array (CTA) to search for thermally produced dark matter at TeV scale, via associated gamma-ray signal from pair-annihilating particles in region around Galactic centre. find that CTA will open a new window discovery potential, significantly extending range robustly testable models given standard cuspy profile density distribution. Importantly, even cored profile, projected sensitivity be sufficient probe various...
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...
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...
We analyze the parsec-scale jet kinematics from 2007 June to 2018 December of a sample $\gamma$-ray bright blazars monitored roughly monthly with Very Long Baseline Array at 43 GHz under VLBA-BU-BLAZAR program. implement novel piece-wise linear fitting method derive 521 distinct emission knots total 3705 intensity images in 22 quasars, 13 BL Lacertae objects, and 3 radio galaxies. Apparent speeds these components range $0.01c$ $78c$, 18.6\% (other than "core") are quasi-stationary. One-fifth...
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 combine time-dependent multi-waveband flux and linear polarization observations with sub-milliarcsecond-scale polarimetric images at lambda=7mm of the BL Lacertae-type blazar OJ287 to locate gamma-ray emission in prominent flares jet source >14pc from central engine. demonstrate a highly significant correlation between strongest millimeter-wave through Monte-Carlo simulations. The two reported peaks occurred near beginning major mm-wave outbursts, each which is associated maximum...
We analyze the behavior of parsec-scale jet quasar 3C 454.3 during pronounced flaring in 2005–2008. Three major disturbances propagated down along different trajectories with Lorentz factors Γ > 10. The show a clear connection millimeter-wave outbursts, 2005 May/June, 2007 July, and December. High-amplitude optical events R-band light curve precede peaks outbursts by 15–50 days. Each outburst is accompanied an increase X-ray activity. associate propagation superluminal knots derive location...
We present time-resolved broad-band observations of the quasar 3C 279 obtained from multi-wavelength campaigns conducted during first two years Fermi Gamma-ray Space Telescope mission. While investigating previously reported gamma-ray/optical flare accompanied by a change in optical polarization, we found that emission appears delayed with respect to gamma-ray about 10 days. X-ray reveal pair `isolated' flares separated ~90 days, only weak counterparts. The spectral structure measured...
We analyze the multifrequency behavior of quasar 3C 454.3 during three prominent \gamma-ray outbursts: 2009 Autumn, 2010 Spring, and Autumn. The data reveal a repeating pattern, including triple flare structure, in properties each outburst, which implies similar mechanism(s) location for all events. multi-frequency indicates that lower frequency events are co-spatial with outbursts, although emission varies on shortest timescales. determine variability from UV to IR wavelengths an outburst...
We analyze the parsec-scale jet kinematics from 2007 June to 2013 January of a sample $\gamma$-ray bright blazars monitored roughly monthly with Very Long Baseline Array at 43~GHz. In total 1929 images, we measure apparent speeds 252 emission knots in 21 quasars, 12 BL~Lacertae objects (BLLacs), and 3 radio galaxies, ranging 0.02$c$ 78$c$; 21\% are quasi-stationary. Approximately 1/3 moving execute non-ballistic motions, quasars exhibiting acceleration along within 5~pc (projected) core,...
We present observations of a major outburst at centimeter, millimeter, optical, X-ray, and γ-ray wavelengths the BL Lacertae object AO 0235+164. analyze timing multi-waveband variations in flux linear polarization, as well changes Very Long Baseline Array images λ = 7 mm with ∼0.15 milliarcsec resolution. The association events different wavebands is confirmed high statistical significance by probability arguments Monte Carlo simulations. A series sharp peaks optical pronounced maximum...
Since the launch of Fermi satellite, BL Lacertae has been moderately active at gamma-rays and optical frequencies until May 2011, when source started a series strong flares. The exceptional sampling achieved by GLAST-AGILE Support Program (GASP) Whole Earth Blazar Telescope (WEBT) in collaboration with Steward Observatory allows us to perform detailed comparison daily gamma-ray observations Fermi. Discrete correlation analysis between emission reveals time lag 0 +- 1 d, which suggests...
The All-sky Medium Energy Gamma-ray Observatory (AMEGO) is a probe class mission concept that will provide essential contributions to multimessenger astrophysics in the late 2020s and beyond. AMEGO combines high sensitivity 200 keV 10 GeV energy range with wide field of view, good spectral resolution, polarization sensitivity. Therefore, key study astrophysical objects have unique signatures gamma-ray regime, such as neutron star mergers, supernovae, flaring active galactic nuclei....
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...
Extended and delayed emission around distant TeV sources induced by the effects of propagation gamma rays through intergalactic medium can be used for measurement magnetic field (IGMF). We search GeV from hard-spectrum blazar 1ES 0229+200 with goal to detect or constrain IGMF-dependent secondary flux generated during medium. analyze most recent MAGIC observations over a 5 year time span complement them historic data H.E.S.S. VERITAS telescopes along 12-year long exposure Fermi/LAT telescope....
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...