0000000000471912
AUTHOR
A. Treves
Search for Pulsed Gamma Ray Emission above 50 MeV from NP 0532
OBSERVATIONS of the pulsar NP 0532 in the gamma ray region have yielded evidence of pulsed gamma ray emission for energies up to 10 MeV (refs. 1, 2 and Kurfess, to be published). Above this energy, upper limits between 10 MeV and 150 MeV (refs. 3, 4) and above 50 MeV (ref. 5) are indicated. A result above 70 MeV with phase error of 3 ms with respect to optical signal has been given by a counter experiment6.
The NHXM observatory
Exploration of the X-ray sky has established X-ray astronomy as a fundamental astrophysical discipline. While our knowledge of the sky below 10 keV has increased dramatically (∼8 orders of magnitude) by use of grazing incidence optics, we still await a similar improvement above 10 keV, where to date only collimated instruments have been used. Also ripe for exploration is the field of X-ray polarimetry, an unused fundamental tool to understand the physics and morphology of X-ray sources. Here we present a novel mission, the New Hard X-ray Mission (NHXM) that brings together for the first time simultaneous high-sensitivity, hard-X-ray imaging, broadband spectroscopy and polarimetry. NHXM will…
Multifrequency Studies of the Peculiar Quasar 4C +21.35 during the 2010 Flaring Activity
著者人数: 290名
Multiband variability studies and novel broadband SED modeling of Mrk 501 in 2009
Astronomy and astrophysics 603, A31 (2017). doi:10.1051/0004-6361/201629540
REM near-IR and optical multiband observations of PKS 2155-304 in 2005 : Erratum
Fernandez Soto, Alberto, Alberto.Fernandez@uv.es
First Multi-wavelength Campaign on the Gamma-ray-loud Active Galaxy IC 310
The extragalactic VHE gamma-ray sky is rich in blazars. These are jetted active galactic nuclei viewed at a small angle to the line-of-sight. Only a handful of objects viewed at a larger angle are known so far to emit above 100 GeV. Multi-wavelength studies of such objects up to the highest energies provide new insights into the particle and radiation processes of active galactic nuclei. We report the results from the first multi-wavelength campaign observing the TeV detected nucleus of the active galaxy IC 310, whose jet is observed at a moderate viewing angle of 10 deg - 20 deg. The multi-instrument campaign was conducted between 2012 Nov. and 2013 Jan., and involved observations with MAG…
Possible pulsed gamma ray emission above 50 MeV from the Crab pulsar.
A SEARCH for pulsed gamma ray emission from NP 0532 has been carried out with a balloon-borne experiment using a spark chamber as the central detector. This pulsar, situated in the Crab Nebula, is already known to pulsate in the radio, optical and X-ray range1–5.
Black hole lightning due to particle acceleration at subhorizon scales
Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry, but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here, we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC telescopes revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20\% of the gravitational radius of its central black hole. We suggest that the emission is associated …