POWERFUL HIGH-ENERGY EMISSION OF THE REMARKABLE BL Lac OBJECT S5 0716+714

Journal Article · Tue Dec 01 00:00:00 EST 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/706/2/1433· OSTI ID:21378094

Vittorini, V; Chen, A W; Ferrari, A ^[1]; Tavani, M; D'Ammando, F; Donnarumma, I; Pacciani, L; Pucella, G ^[2]; Paggi, A; Cavaliere, A ^[3]; Bulgarelli, A ^[4]; Giuliani, A; Vercellone, S ^[5]; Longo, F ^[6]; Colafrancesco, S; Giommi, P ^[7]

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1. CIFS-Torino, Viale Settimio Severo 3, I-10133, Torino (Italy)
2. INAF/IASF-Roma, Via del Fosso del Cavaliere 100, I-00133 Roma (Italy)
3. University of Rome, 'Tor Vergata', Via della Ricerca Scientifica 1, I-00133 Roma (Italy)
4. INAF/IASF-Bologna, Via Gobetti 101, I-40129 Bologna (Italy)
5. INAF/IASF-Milano, Via E. Bassini 15, I-20133 Milano (Italy)
6. INFN-Trieste, Via Valerio 2, I-34127 Trieste (Italy)
7. ASDC c/o ESRIN, Via G. Galilei snc, I-00044 Frascati, Roma (Italy)

BL Lac objects of the intermediate subclass (IBLs) are known to emit a substantial fraction of their power in the energy range 0.1-10 GeV. Detecting gamma-ray emission from such sources provides therefore a direct probe of the emission mechanisms and of the underlying powerhouse. The gamma-ray satellite, AGILE, detected the remarkable IBL S5 0716+714 (z approx = 0.3) during a high state in the period from 2007 September-October, marked by two very intense flares reaching peak fluxes of 200 x 10{sup -8} photons cm{sup -2} s{sup -1} above 100 MeV, with simultaneous optical and X-ray observations. We present here a theoretical model for the two major flares and discuss the overall energetics of the source. We conclude that 0716+714 is among the brightest BL Lac's ever detected at gamma-ray energies. Because of its high power and lack of signs for ongoing accretion or surrounding gas, the source is an ideal candidate to test the maximal power extractable from a rotating supermassive black hole via the pure Blandford-Znajek (BZ) mechanism. We find that during the 2007 gamma-ray flares 0716+714 approached or just exceeded the upper limit set by BZ for a black hole of mass 10{sup 9} M{sub sun}.

• OSTI ID: 21378094
• Journal Information: Astrophysical Journal, Vol. 706, Issue 2; Other Information: DOI: 10.1088/0004-637X/706/2/1433; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
BL LACERTAE OBJECTS
BLACK HOLES
GAMMA RADIATION
GEV RANGE 01-10
MASS
MEV RANGE 100-1000
PHOTON EMISSION
PHOTONS
SATELLITES
X RADIATION
BOSONS
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
EMISSION
ENERGY RANGE
GEV RANGE
IONIZING RADIATIONS
MASSLESS PARTICLES
MEV RANGE
RADIATIONS