The red blazar PMN J2345-1555 becomes blue
The red blazar PMN J2345-1555 becomes blue
复制标题
DOI：
10.1093/mnrasl/slt041
复制
发表时间：
2013-02
影响因子：
4.8
通讯作者：
G. Ghisellini;F. Tavecchio;L. Foschini;G. Bonnoli;G. Tagliaferri
中科院分区：
文献类型：
--
作者：
G. Ghisellini;F. Tavecchio;L. Foschini;G. Bonnoli;G. Tagliaferri
平谱射电类星体PMN J2345-1555是一个明亮的伽马射线源，最近经历了红外，紫外和伽马射线波段的耀斑事件。通量在不同的频率下准同时变化，这表明它是由单个发射粒子群产生的，因此是由射流的单个和局部区域产生的。虽然耀斑前的光谱能量分布（SED）是典型的强大耀变体（即两个宽峰分别在远红外和低于100 MeV波段），在耀斑期间，峰值移动到光学紫外和能量大于1 GeV，类似于低功率BL Lac天体，即使观测到的热光度增加了一个以上的数量级。我们解释这种行为是由于在射流中的发射区域的位置的变化，从宽线区域内，就在外面。在喷流的同动坐标系中，辐射能量密度的相应降低使得相对论电子被加速到更高的能量，从而产生“更蓝”的SED。
The Flat Spectrum Radio Quasar PMN J2345-1555 is a bright gamma-ray source, that recently underwent a flaring episode in the IR, UV and gamma-ray bands. The flux changed quasi simultaneously at different frequencies, suggesting that it was produced by a single population of emitting particles, hence by a single and well localized region of the jet. While the overall Spectral Energy Distribution (SED) before the flare was typical of powerful blazars (namely two broad humps peaking in the far IR and below 100 MeV bands, respectively), during the flare the peaks moved to the optical-UV and to energies larger than 1 GeV, to resemble low power BL Lac objects, even if the observed bolometric luminosity increased by more than one order of magnitude. We interpret this behavior as due to a change of the location of the emission region in the jet, from within the broad line region, to just outside. The corresponding decrease of the radiation energy density as seen in the comoving frame of the jet allowed the relativistic electrons to be accelerated to higher energies, and thus produce a "bluer" SED.