VHE ?-ray discovery and multi-wavelength study of the blazar 1ES 2322-409
VHE ?-ray discovery and multi-wavelength study of the blazar 1ES 2322-409
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耀变体 1ES 2322-409 的 VHE γ 射线发现和多波长研究
DOI：
10.1093/mnras/sty2686
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发表时间：
2018
影响因子：
4.8
通讯作者：
Collaboration H
中科院分区：
文献类型：
--
作者：
Collaboration H
在与BL Lac天体1 ES 2322-409兼容的位置处的热点偶然地用H.E.S.S.在2004年和2006年对blazar PKS 2316-423进行的观测中，在2011年和2012年获得了1 ES 2322-409的额外数据，导致总生存时间为22.3小时。在1 ES 2322-409位置的一个源中探测到了点状甚高能（VHE; E> 100 GeV）射线发射，在6.0的显著性下有116.7个事件。平均VHE射线谱可以用幂律方程很好地描述，其光子指数和积分通量$\Phi（E> 200 GeV）=（3.11\pm0.71_{\rm stat}\pm0.62_{\rm sys}）\times10^{-12} cm^{-2} s^{-1}$，相当于蟹状星云200 GeV以上通量的1.1倍。Fermi LAT、Swift XRT和UVOT、RXTE PCA、ATOM获得的多波长数据，以及WISE、GROND和卡塔利纳获得的额外数据，也被用来计算1 ES 2322-409的宽带非热发射。多波长的行为表明日尺度的变化。Swift UVOT和XRT数据显示较长尺度下的强烈变异性。一个光谱能量分布（SED）是建立从周围的高状态确定的雨燕数据获得的同期观测。一个建模的SED进行与一个固定的均匀的单区同步自康普顿（SSC）轻子模型。源的红移是未知的，两个合理的值进行了测试的建模。系统扫描的模型参数空间进行，导致在一个良好的约束组合的值提供了一个很好的描述1 ES 2322-409的宽带行为。
A hotspot at a position compatible with the BL Lac object 1ES 2322-409 was serendipitously detected with H.E.S.S. during observations performed in 2004 and 2006 on the blazar PKS 2316-423. Additional data on 1ES 2322-409 were taken in 2011 and 2012, leading to a total live-time of 22.3h. Point-like very-high-energy (VHE; E>100GeV)-ray emission is detected from a source centred on the 1ES 2322-409 position, with an excess of 116.7 events at a significance of 6.0. The average VHE-ray spectrum is well described with a power law with a photon indexand an integral flux $\Phi(E>200GeV) = (3.11\pm0.71_{\rm stat}\pm0.62_{\rm sys})\times10^{-12} cm^{-2} s^{-1}$, which corresponds to 1.1of the Crab nebula flux above 200 GeV. Multi-wavelength data obtained with Fermi LAT, Swift XRT and UVOT, RXTE PCA, ATOM, and additional data from WISE, GROND and Catalina, are also used to characterise the broad-band non-thermal emission of 1ES 2322-409. The multi-wavelength behaviour indicates day-scale variability. Swift UVOT and XRT data show strong variability at longer scales. A spectral energy distribution (SED) is built from contemporaneous observations obtained around a high state identified in Swift data. A modelling of the SED is performed with a stationary homogeneous one-zone synchrotron-self-Compton (SSC) leptonic model. The redshift of the source being unknown, two plausible values were tested for the modelling. A systematic scan of the model parameters space is performed, resulting in a well-constrained combination of values providing a good description of the broad-band behaviour of 1ES 2322-409.