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Schlagworte
- gamma rays: galaxies (11)
- BL Lacertae objects: general (9)
- gamma rays: general (8)
- galaxies: active (6)
- acceleration of particles (4)
- astroparticle physics (4)
- binaries: general (4)
- gamma rays: stars (3)
- gamma-rays: general (3)
- radiation mechanisms: non-thermal (3)
- BL Lacertae objects: individual (B2 1215+30, VER J1217+301) (2)
- BL Lacertae objects: individual: Mrk 421 (2)
- BL Lacertae objects: individual: Mrk 501 (2)
- Galaxy: center (2)
- ISM: supernova remnants (2)
- X-rays: binaries (2)
- diffuse radiation (2)
- galaxies: jets (2)
- galaxies: nuclei (2)
- magnetic fields (2)
- methods: data analysis (2)
- pulsars: general (2)
- relativistic processes (2)
- BL Lacertae objects: individual (1ES 0229+200, VER J0232+202) (1)
- BL Lacertae objects: individual (1ES 1959+650) (1)
- BL Lacertae objects: individual (1ES 1959+650=VER J1959+651) (1)
- BL Lacertae objects: individual (1ES1218+30.4) (1)
- BL Lacertae objects: individual (PKS 1424+240)-cosmic background radiation (1)
- BL Lacertae objects: individual (VER J0521+211) (1)
- BL Lacertae objects: individual: 1ES 2344+514=VERJ2347+517 (1)
- BL Lacertae objects: individual: Markarian 501 (1)
- IACT (1)
- ISM: individual objects (Crab Nebula) (1)
- Instrumentation (1)
- Moonlight (1)
- Observing methods (1)
- VERITAS (1)
- X-rays: galaxies (1)
- X-rays: individual (Cygnus X-3) (1)
- astrobiology (1)
- binaries: close (1)
- black hole physics (1)
- cosmic background radiation (1)
- cosmic rays (1)
- data behind figure (1)
- extraterrestrial intelligence (1)
- galaxies: Seyfert (1)
- galaxies: active-galaxies: individual: PMN J0948+0022 (1)
- galaxies: individual (Markarian 501) (1)
- galaxies: individual (RGB J2243+203) (1)
- galaxies: individual: 1ES 1741+196=VER J1744+195 (1)
- gamma rays : stars (1)
- gamma rays: general(HESS J0632+057, VER J0633+057) (1)
- gamma-ray burst: individual (GRB 130427A) (1)
- gamma-ray burst: individual (MGRO J1908+06, VER J1907+062) (1)
- gamma-rays: galaxies (1)
- material (1)
- methods: observational (1)
- pulsars : individual (PSR J2021+3651) (1)
- pulsars: individual (PSR J0633+1746, Geminga) (1)
- pulsars: individual (PSR J1023+0038) (1)
- pulsars: individual (PSR J1907+0602) (1)
- pulsars: individual (PSR J2032+4127) (1)
- stars: individual ( KIC 8462852) (1)
- stars: individual (LS I+61 degrees 303, VER J0240+612) (1)
- supernovae : individual (CTB 87) (1)
- supernovae: individual (G0.9+0.1) (1)
- techniques: photometric (1)
Institut
We report the discovery of an unidentified, extended source of very-high-energy gamma-ray emission, VER J2019+407, within the radio shell of the supernova remnant SNR G78.2+2.1, using 21.4 hr of data taken by the VERITAS gamma-ray observatory in 2009. These data confirm the preliminary indications of gamma-ray emission previously seen in a two-year (2007-2009) blind survey of the Cygnus region by VERITAS. VER J2019+407, which is detected at a post-trials significance of 7.5 standard deviations in the 2009 data, is localized to the northwestern rim of the remnant in a region of enhanced radio and X-ray emission. It has an intrinsic extent of 0 degrees.23 +/- 0 degrees.03(stat-0 degrees.02sys)(+0 degrees.04) and its spectrum is well-characterized by a differential power law (dN/dE = N-0 x (E/TeV)-Gamma) with a photon index of Gamma = 2.37 +/- 0.14(stat) +/- 0.20(sys) and a flux normalization of N-0 = 1.5 +/- 0.2(stat) +/- 0.4(sys) x 10(-12) photon TeV-1 cm(-2) s(-1). This yields an integral flux of 5.2 +/- 0.8(stat) +/- 1.4(sys) x 10(-12) photon cm(-2) s(-1) above 320 GeV, corresponding to 3.7% of the Crab Nebula flux. We consider the relationship of the TeV gamma-ray emission with the GeV gamma-ray emission seen from SNR G78.2+2.1 as well as that seen from a nearby cocoon of freshly accelerated cosmic rays. Multiple scenarios are considered as possible origins for the TeV gamma-ray emission, including hadronic particle acceleration at the SNR shock.