E. Lindfors
A5057505705- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Neutrino Physics Research
- Particle Accelerators and Free-Electron Lasers
- Particle Detector Development and Performance
- Pulsars and Gravitational Waves Research
- Astronomical Observations and Instrumentation
- Particle physics theoretical and experimental studies
- Solar and Space Plasma Dynamics
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Gyrotron and Vacuum Electronics Research
- Cosmology and Gravitation Theories
- Particle accelerators and beam dynamics
- Stellar, planetary, and galactic studies
- Adaptive optics and wavefront sensing
- Calibration and Measurement Techniques
- Computational Physics and Python Applications
- Precipitation Measurement and Analysis
- Noncommutative and Quantum Gravity Theories
- Superconducting Materials and Applications
- Nuclear Physics and Applications
University of Turku
2015-2024
Turku Centre for Computer Science
2014-2024
Vaisala (Finland)
2006-2024
Instituto de Astrofísica de Canarias
2017-2024
Universidad de La Laguna
2012-2024
CTA Observatory
2021-2023
Max Planck Institute for Physics
2018-2023
MAGIC Telescopes
2007-2023
Durham University
2023
University of Łódź
2016-2023
The blazar Mrk 501 was observed at energies above 0.10 TeV with the MAGIC Telescope from 2005 May through July. high sensitivity of instrument enabled determination flux and spectrum source on a night-by-night basis. Throughout our observational campaign, found to vary by an order magnitude. Intranight variability flux-doubling times down 2 minutes during two most active nights, namely, June 30 July 9. These are fastest variations ever in 501. ~20 minute long flare 9 showed indication 4 ± 1...
The atmospheric Cherenkov gamma-ray telescope MAGIC, designed for a low-energy threshold, has detected very-high-energy gamma rays from giant flare of the distant Quasi-Stellar Radio Source (in short: radio quasar) 3C 279, at distance more than 5 billion light-years (a redshift 0.536). No quasar been observed previously in radiation, and this is also most object emitting above 50 gigaelectron volts. Because high-energy may be stopped by interacting with diffuse background light universe,...
Microquasars are binary star systems with relativistic radio-emitting jets. They potential sources of cosmic rays and can be used to elucidate the physics We report detection variable gamma-ray emission above 100 gigaelectron volts from microquasar LS I 61 + 303. Six orbital cycles were recorded. Several detections occur at a similar phase, which suggests that is periodic. The strongest not observed when two stars closest one another, implying strong modulation or absorption processes.
Very high energy (VHE) γ-ray emission from the flat spectrum radio quasar (FSRQ) PKS 1222+21 (4C 21.35, z = 0.432) was detected with MAGIC Cherenkov telescopes during a short observation (∼0.5 hr) performed on 2010 June 17. The detection coincides high-energy MeV/GeV activity measured by Large Area Telescope (LAT) board Fermi satellite. VHE extends about 70 GeV up to at least 400 and can be well described power-law dN/dE ∝ E−Γ photon index Γ 3.75 ± 0.27stat 0.2syst. averaged integral flux...
We report about very high energy (VHE) γ-ray observations of the Crab Nebula with MAGIC telescope. The flux from nebula was measured between 60 GeV and 9 TeV. spectrum can be described by a curved power law dF/dE = f0(E/300 GeV)[a+blog10(E/300 GeV)] normalization f0 (6.0 ± 0.2stat) × 10−10 cm−2 s−1 TeV−1, − 2.31 0.06stat, b 0.26 0.07stat. peak in spectral distribution is estimated at 77 35 GeV. Within observation time experimental resolution telescope, emission steady pointlike. emission's...
Abstract A neutrino with energy ∼290 TeV, IceCube-170922A, was detected in coincidence the BL Lac object TXS 0506+056 during enhanced gamma-ray activity, chance being rejected at ∼3 σ level. We monitored very-high-energy (VHE) band Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes for ∼41 hr from 1.3 to 40.4 days after detection. Day-timescale variability is clearly resolved. interpret quasi-simultaneous and broadband electromagnetic observations a novel one-zone...
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 timing of photons observed by MAGIC telescope during a flare active galactic nucleus Mkn 501 for possible correlation with energy, as suggested some models quantum gravity (QG), which predict vacuum refractive index ≃1+(E/MQGn)n, n=1,2. Parametrizing delay between γ-rays different energies Δt=±τlE or Δt=±τqE2, we find τl=(0.030±0.012) s/GeV at 2.5-σ level, and τq=(3.71±2.57)×10−6 s/GeV2, respectively. use these results to establish lower limits MQG1>0.21×1018 GeV...
We report on the results from observations in very high energy band (VHE; Eγ ≥ 100 GeV) of black hole X-ray binary (BHXB) Cygnus X-1. The were performed with MAGIC telescope, for a total 40 hr during 26 nights, spanning period between 2006 June and November. Searches steady γ-ray signals yielded no positive result, upper limits to integral flux ranging 1% 2% Crab Nebula flux, depending energy, have been established. also analyzed each observation night independently, obtaining evidence at...
One fundamental question about pulsars concerns the mechanism of their pulsed electromagnetic emission. Measuring high-end region a pulsar's spectrum would shed light on this question. By developing new electronic trigger, we lowered threshold Major Atmospheric gamma-ray Imaging Cherenkov (MAGIC) telescope to 25 GeV. In configuration, detected gamma-rays from Crab pulsar that were greater than GeV, revealing relatively high cutoff energy in phase-averaged spectrum. This indicates emission...
We report the detection of a new source very high energy (VHE; Eγ ≥ 100 GeV) γ-ray emission located close to Galactic plane, MAGIC J0616+225, which is spatially coincident with supernova remnant IC 443. The observations were carried out telescope in periods 2005 December-2006 January and 2006 December-2007 January. Here we present results from this source, leading VHE signal statistical significance 5.7 σ 2006/2007 data measured differential flux consistent power law, described as dNγ/(dA dt...
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...
Recently, the Galactic center has been reported to be a source of very high energy (VHE) γ-rays by CANGAROO, VERITAS, and HESS experiments. The spectra as measured these experiments show substantial differences. In this Letter we present MAGIC observations center, resulting in detection differential γ-ray flux consistent with steady, hard-slope power law, described dNγ/(dA dt dE) = (2.9 ± 0.6) × 10-12(E/TeV)-2.2±0.2 cm-2 s-1 TeV-1. is centered at (R.A., decl.) (17h45m20s, -29°2'). This...
Supermassive black holes with masses of millions to billions solar are commonly found in the centers galaxies. Astronomers seek image jet formation using radio interferometry, but still suffer from insufficient angular resolution. An alternative method resolve small structures is measure time variability their emission. Here, we report on gamma-ray observations galaxy IC 310 obtained MAGIC telescopes revealing doubling scales faster than 4.8 min. Causality constrains size emission region be...
We present simultaneous Planck, Swift, Fermi, and ground-based data for 105 blazars belonging to three samples with flux limits in the soft X-ray, hard gamma-ray bands. Our unique set has allowed us demonstrate that selection method strongly influences results, producing biases cannot be ignored. Almost all BL Lac objects have been detected by Fermi-LAT, whereas ~40% of flat-spectrum radio quasars (FSRQs) radio, X-ray selected are still below detection limit even after integrating 27 months...
We have acquired a deep i-band image of the BL Lacertae object S5 0716+714 while target was in an low optical state. Due to faintness nucleus, we were able detect underlying host galaxy. The galaxy is measured I-band magnitude and effective radius () arcsec. Using as "standard candle", derive (1σ error) for 0716+714. This redshift consistent with determined by spectroscopy 3 galaxies close at would be kpc, which values obtained Lac galaxies. An spectrum during same epoch shows no...
The Perseus galaxy cluster was observed by the MAGIC Cherenkov telescope for a total effective time of 24.4 hr during 2008 November and December. resulting upper limits on gamma-ray emission above 100 GeV are in range 4.6 to 7.5 x 10^{-12} cm^{-2} s^{-1} spectral indices from -1.5 -2.5, thereby constraining produced cosmic rays, dark matter annihilations, central radio NGC1275. Results compatible with cosmological simulations cosmic-ray-induced emission, average ray-to-thermal pressure <4%...
ABSTRACT OJ 287 is a quasi-periodic quasar with roughly 12 year optical cycles. It displays prominent outbursts that are predictable in binary black hole model. The model predicted major outburst 2015 December. We found the did occur within expected time range, peaking on December 5 at magnitude 12.9 R -band. Based Swift /XRT satellite measurements and polarization data, we find it included thermal component. Its timing provides an accurate estimate for spin of primary hole, . present also...
We present the results of stereoscopic observations satellite galaxy Segue 1 with MAGIC Telescopes, carried out between 2011 and 2013. With almost 160 hours good-quality data, this is deepest observational campaign on any dwarf performed so far in very high energy range electromagnetic spectrum. search large data sample for signals dark matter particles mass 100 GeV 20 TeV. For we use full likelihood analysis method, which provides optimal sensitivity to characteristic gamma-ray spectral...
Aims. We investigate the extension of very high-energy spectral tail Crab Pulsar at energies above 400 GeV.