scholarly journals GAMMA-RAY EMISSION FROM THE VELA PULSAR MODELED WITH THE ANNULAR GAP AND THE CORE GAP

2011 ◽  
Vol 731 (1) ◽  
pp. 2 ◽  
Author(s):  
Y. J. Du ◽  
J. L. Han ◽  
G. J. Qiao ◽  
C. K. Chou
Science ◽  
2009 ◽  
Vol 327 (5966) ◽  
pp. 663-665 ◽  
Author(s):  
A. Pellizzoni ◽  
A. Trois ◽  
M. Tavani ◽  
M. Pilia ◽  
A. Giuliani ◽  
...  

2014 ◽  
Vol 28 ◽  
pp. 1460182
Author(s):  
NAREK SAHAKYAN ◽  
FRANK M. RIEGER ◽  
FELIX AHARONIAN ◽  
RUIZHI YANG ◽  
EMMA DE ONA-WILHELMI

We summarize recent results based on an analysis of Fermi-LAT data for the lobes and the core of the nearby radio galaxy Centaurus A (Cen A). In the case of the core, high-energy (HE; > 100 MeV) γ-rays up to 50 GeV have been detected with a detection significance of about 44σ. The average gamma-ray spectrum of the core reveals interesting evidence for a possible deviation from a simple power-law. A likelihood analysis with a broken power-law model shows that the photon index becomes substantially harder above Eb ≃ 4 GeV, changing from Γ1 = 2.74 ± 0.03 below to Γ2 = 2.09 ± 0.20 above. It seems possible that this hardening marks the contribution of an additional high-energy component beyond the common synchrotron-self Compton jet emission. In the case of the lobes, the high-energy gamma-ray emission extends up to 6 GeV, with a significance of more than 10 and 20 σ for the north and the south lobe, respectively. Based on a detailed spatial analysis and comparison with the associated radio lobes, a substantial extension of the HE γ-ray emission beyond the WMAP radio image for the northern lobe of Cen A is found. We provide a short discussion of the lobe's spectral energy distribution (SED) in the context of hadronic and time-dependent leptonic scenarios.


2019 ◽  
Author(s):  
Juan Carlos Rodriguez-Ramirez ◽  
Elisabete Maria de Gouveia Dal Pino ◽  
Rafael Alves Batista

1998 ◽  
Vol 502 (1) ◽  
pp. 428-436 ◽  
Author(s):  
Igor V. Moskalenko ◽  
Werner Collmar ◽  
Volker Schonfelder

2021 ◽  
pp. 109559
Author(s):  
R.F.P. Simões ◽  
C.J. da Silva ◽  
R.L. da Silva ◽  
L.V. de Sá ◽  
R. Poledna ◽  
...  

2018 ◽  
Vol 614 ◽  
pp. L1 ◽  
Author(s):  
A. Lähteenmäki ◽  
E. Järvelä ◽  
V. Ramakrishnan ◽  
M. Tornikoski ◽  
J. Tammi ◽  
...  

We have detected six narrow-line Seyfert 1 (NLS1) galaxies at 37 GHz that were previously classified as radio silent and two that were classified as radio quiet. These detections reveal the presumption that NLS1 galaxies labelled radio quiet or radio silent and hosted by spiral galaxies are unable to launch jets to be incorrect. The detections are a plausible indicator of the presence of a powerful, most likely relativistic jet because this intensity of emission at 37 GHz cannot be explained by, for example, radiation from supernova remnants. Additionally, one of the detected NLS1 galaxies is a newly discovered source of gamma rays and three others are candidates for future detections.


2017 ◽  
Author(s):  
S. V. Bogovalov ◽  
F. Aharonian ◽  
D. Khangulyan

2017 ◽  
Vol 12 (04) ◽  
pp. E04001-E04001
Author(s):  
G Petringa ◽  
G.A.P Cirrone ◽  
C Caliri ◽  
G Cuttone ◽  
L Giuffrida ◽  
...  

2010 ◽  
Vol 712 (1) ◽  
pp. L10-L15 ◽  
Author(s):  
S. Sabatini ◽  
M. Tavani ◽  
E. Striani ◽  
A. Bulgarelli ◽  
V. Vittorini ◽  
...  
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