crta
Hrvatska znanstvena Sekcija img
bibliografija
3 gif
 Naslovna
 O projektu
 FAQ
 Kontakt
4 gif
Pregledavanje radova
Jednostavno pretraživanje
Napredno pretraživanje
Skupni podaci
Upis novih radova
Upute
Ispravci prijavljenih radova
Ostale bibliografije
Slični projekti
 Bibliografske baze podataka

Pregled bibliografske jedinice broj: 817228

Časopis

Autori: Ahnen, Max Ludwig; ...; Babić, Ana; ...; Dominis Prester, Dijana; ...; Godinović, Nikola; ...; Hrupec, Dario; ...; Lelas, Damir; ...; Manganaro, Marina; ...; Puljak, Ivica; ...; Šnidarić, Iva; ...; Terzić, Tomislav; ...; Zanin, Roberta
Naslov: MAGIC observations of the February 2014 flare of 1ES 1011+496 and ensuing constraint of the EBL density
Izvornik: Astronomy & astrophysics (0004-6361) 590 (2016);
Vrsta rada: članak
Ključne riječi: BL Lacertae objects ; general ; intergalactic medium ; cosmic background radiation
Sažetak:
During February–March 2014, the MAGIC telescopes observed the high-frequency peaked BL Lac 1ES 1011+496 (z = 0.212) in flaring state at very-high energy (VHE, E> 100 GeV). The flux reached a level of more than ten times higher than any previously recorded flaring state of the source. To describe the characteristics of the flare presenting the light curve and the spectral parameters of the night-wise spectra and the average spectrum of the whole period. From these data we aim to detect the imprint of the extragalactic background light (EBL) in the VHE spectrum of the source, to constrain its intensity in the optical band. We analyzed the gamma-ray data from the MAGIC telescopes using the standard MAGIC software for the production of the light curve and the spectra. To constrain the EBL, we implement the method developed by the H.E.S.S. collaboration, in which the intrinsic energy spectrum of the source is modeled with a simple function (≤4 parameters), and the EBL-induced optical depth is calculated using a template EBL model. The likelihood of the observed spectrum is then maximized, including a normalization factor for the EBL opacity among the free parameters. The collected data allowed us to describe the night-wise flux changes and also to produce differential energy spectra for all nights in the observed period. The estimated intrinsic spectra of all the nights could be fitted by power-law functions. Evaluating the changes in the fit parameters, we conclude that the spectral shape for most of the nights were compatible, regardless of the flux level, which enabled us to produce an average spectrum from which the EBL imprint could be constrained. The likelihood ratio test shows that the model with an EBL density 1.07 (–0.20, +0.24)stat+sys, relative to the one in the tested EBL template, is preferred at the 4.6σ level to the no-EBL hypothesis, with the assumption that the intrinsic source spectrum can be modeled as a log-parabola. This would translate into a constraint of the EBL density in the wavelength range [0.24 μm, 4.25 μm], with a peak value at 1.4 μm of λFλ = 12.27-2.29+2.75 nW m-2 sr-1, including systematics.
Izvorni jezik: ENG
Rad je indeksiran u
bazama podataka:
Current Contents Connect (CCC)
Scopus
SCI-EXP, SSCI i/ili A&HCI
Science Citation Index Expanded (SCI-EXP) (sastavni dio Web of Science Core Collectiona)
Kategorija: Znanstveni
Znanstvena područja:
Fizika
URL Internet adrese: http://www.aanda.org/articles/aa/abs/2016/06/aa27256-15/aa27256-15.html
http://arxiv.org/abs/1602.05239v2
Broj citata:
Altmetric:
DOI: 10.1051/0004-6361/201527256
URL cjelovitog teksta:
Google Scholar: MAGIC observations of the February 2014 flare of 1ES 1011+496 and ensuing constraint of the EBL density
Upisao u CROSBI: Tomislav Terzić (tterzic@phy.uniri.hr), 20. Svi. 2016. u 14:22 sati



  Verzija za printanje   za tiskati


upomoc
foot_4