7 research outputs found
Multiwavelength Picture of the Blazar S5 0716+714 during Its Brightest Outburst
S5 0716+714 is a well known BL Lac object, and one of the brightest and
most active blazars. The discovery in the Very High Energy band (VHE, E
> 100 GeV) by MAGIC happened in 2008. In January 2015, the source
went through the brightest optical state ever observed, triggering MAGIC
follow-up and a VHE detection with ⌠13Ï significance (ATel âŻ6999 ).
Rich multiwavelength coverage of the flare allowed us to construct the
broad-band spectral energy distribution of S5 0716+714 during its
brightest outburst. In this work, we will present the preliminary
analysis of MAGIC and Fermi-LAT data of the flaring activity in
January and February 2015 for the HE (0.1 < HE < 300 GeV) and VHE
band, together with radio (MetsÀhovi, OVRO, VLBA, Effelsberg),
sub-millimeter (SMA), optical (Tuorla, Perkins, Steward, AZT-8+ST7,
LX-200, Kanata), X-ray and UV (Swift-XRT and UVOT), in the same
time-window and discuss the time variability of the multiwavelength
light curves during this impressive outburst.</p
Correlated neutrino and gamma-ray emission from Active Galactic Nuclei - an estimation
info:eu-repo/semantics/publishe
Multiwavelength Picture of the Blazar S5 0716+714 during Its Brightest Outburst
S5 0716+714 is a well known BL Lac object, and one of the brightest and most active blazars. The discovery in the Very High Energy band (VHE, E > 100 GeV) by MAGIC happened in 2008. In January 2015, the source went through the brightest optical state ever observed, triggering MAGIC follow-up and a VHE detection with ⌠13 Ï significance (ATel ⯠6999 ). Rich multiwavelength coverage of the flare allowed us to construct the broad-band spectral energy distribution of S5 0716+714 during its brightest outburst. In this work, we will present the preliminary analysis of MAGIC and Fermi-LAT data of the flaring activity in January and February 2015 for the HE (0.1 < HE < 300 GeV) and VHE band, together with radio (MetsĂ€hovi, OVRO, VLBA, Effelsberg), sub-millimeter (SMA), optical (Tuorla, Perkins, Steward, AZT-8+ST7, LX-200, Kanata), X-ray and UV (Swift-XRT and UVOT), in the same time-window and discuss the time variability of the multiwavelength light curves during this impressive outburst
Very high energy gamma-ray observation of the peculiar transient event Swift J1644+57 with the MAGIC telescopes and AGILE
Context. On March 28, 2011, the BAT instrument on board the Swift satellite detected a new transient event that in the very beginning was classified as a gamma ray burst (GRB). However, the unusual X-ray flaring activity observed from a few hours up to days after the onset of the event made a different nature seem to be more likely. The long-lasting activity in the X-ray band, followed by a delayed brightening of the source in infrared and radio activity, suggested that it is better interpreted as a tidal disruption event that triggered a dormant black hole in the nucleus of the host galaxy and generated an outflowing jet of relativistic matter. Aims. Detecting a very high energy emission component from such a peculiar object would be enable us to constrain the dynamic of the emission processes and the jet model by providing information on the Doppler factor of the relativistic ejecta. Methods. The MAGIC telescopes observed the peculiar source Swift J1644+57 during the flaring phase, searching for gamma-ray emission at very-high energy (VHE, E > 100 GeV), starting observations nearly 2.5 days after the trigger time. MAGIC collected a total of 28 h of data during 12 nights. The source was observed in wobble mode during dark time at a mean zenith angle of 35 degrees. Data were reduced using a new image-cleaning algorithm, the so-called sum-cleaning, which guarantees a better noise suppression and a lower energy threshold than the standard analysis procedure. Results. No clear evidence for emission above the energy threshold of 100 GeV was found. MAGIC observations permit one to constrain the emission from the source down to 100 GeV, which favors models that explain the observed lower energy variable emission. Data analysis of simultaneous observations from AGILE, Fermi and VERITAS also provide negative detection, which additionally constrain the self-Compton emission component