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Titolo:
Extreme synchrotron BL Lac objects - Stretching the blazar sequence
Autore:
Costamante, L; Ghisellini, G; Giommi, P; Tagliaferri, G; Celotti, A; Chiaberge, M; Fossati, G; Maraschi, L; Tavecchio, F; Treves, A; Wolter, A;
Indirizzi:
Osservatorio Astron Brera, Merate, Italy Osservatorio Astron Brera Merate Italy orio Astron Brera, Merate, Italy Univ Milan, Milan, Italy Univ Milan Milan ItalyUniv Milan, Milan, Italy ESA, ESRIN, ASI, Sci Data Ctr, Frascati, Italy ESA Frascati ItalyESA, ESRIN, ASI, Sci Data Ctr, Frascati, Italy SISSA, ISAS, Trieste, Italy SISSA Trieste ItalySISSA, ISAS, Trieste, Italy Univ Calif San Diego, CASS, La Jolla, CA 92093 USA Univ Calif San Diego La Jolla CA USA 92093 , CASS, La Jolla, CA 92093 USA Osservatorio Astron Brera, Milan, Italy Osservatorio Astron Brera Milan Italy atorio Astron Brera, Milan, Italy Univ Insubria, Como, Italy Univ Insubria Como ItalyUniv Insubria, Como, Italy
Titolo Testata:
ASTRONOMY & ASTROPHYSICS
fascicolo: 2, volume: 371, anno: 2001,
pagine: 512 - 526
SICI:
1432-0746(200105)371:2<512:ESBLO->2.0.ZU;2-N
Fonte:
ISI
Lingua:
ENG
Soggetto:
X-RAY-SPECTRA; ABSORPTION CROSS-SECTIONS; LACERTAE OBJECTS; ENERGY-DISTRIBUTIONS; GAMMA-RAYS; EMISSION; PKS-0548-322; RADIATION; GALAXIES;
Keywords:
BL Lacertae objects : individual : 1ES 0033+595; 1ES 0120+340, PKS 0548-322, GB 1114+203, 1ES 1218+304, 1ES 1426+428, H 2356-309 X-rays : general; TeV : general;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
49
Recensione:
Indirizzi per estratti:
Indirizzo: Costamante, L Osservatorio Astron Brera, Via Bianchi 46, Merate, Italy Osservatorio Astron Brera Via Bianchi 46 Merate Italy taly
Citazione:
L. Costamante et al., "Extreme synchrotron BL Lac objects - Stretching the blazar sequence", ASTRON ASTR, 371(2), 2001, pp. 512-526

Abstract

We performed an observational program with the X-ray satellite BeppoSAX, to study objects with extreme synchrotron peak frequencies (nu (peak) > 1 keV). Of the seven sources observed, five revealed or confirmed their extremenature. Four showed peak frequencies in the range 1-5 keV, while one (1ES 1426+428) displayed a at power law spectrum (alphax = 0.92 +/-0.04) which locates its synchrotron peak at or above 100 keV. This is the third source of this type ever found, after Mkn 501 and 1ES 2344+514. In the context of the whole blazar class, the broad band properties of these objects confirm the scenario of a synchrotron peak smoothly spanning the IR - X-ray range, which explains the multi-frequency properties of the blazar class. Our data also confirm the large nu (peak) variability which seems to characterize this class of sources, compared with lower nu (peak) objects. Given the high synchrotron peak energies, which ag the presence of high energy electrons, these extreme BL Lacs are also good candidates for TeV emission, and therefore good probes of the IR background.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/04/20 alle ore 11:38:27