X-rays from the radio-quiet quasar PG 1407+265: relativistic jet or accretion disc emission?
X-rays from the radio-quiet quasar PG 1407+265: relativistic jet or accretion disc emission?
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DOI：
10.1111/j.1365-2966.2005.09780.x
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发表时间：
2005-10
影响因子：
4.8
通讯作者：
L. Gallo
中科院分区：
文献类型：
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作者：
L. Gallo
我们提出了两个xmm -牛顿观测到的发光（L x > 10 46 erg s -1），射电安静类星体PG 1407+265，相隔11个月。数据显示了两个不同的状态：一个高度可变的明亮状态（第一历元）；还有一个静止的、低通量的周期（第二周期）。在低通量状态下，光谱符合单一的、未吸收的幂律。然而，在较亮的状态下，统计上需要一个高度可变的陡分量。来自光学监视器的同期紫外线数据允许估计光学- x射线光谱指数（α ox），这在低通量状态下是典型的无线电安静类星体，但在高通量状态下非常平坦。xmm -牛顿的数据可以被描述为起源于射流和吸积盘过程的组合，其中（相对论性）x射线射流只是间歇性地工作。这种情况可以帮助描述PG 1407+265宽带光谱能量分布中的一些复杂性，如弱高电离发射线、强Fe、无光束连续体和相对于光学的弱射电发射。
We present two XMM-Newton observations of the luminous (L x > 10 46 erg s -1 ), radio-quiet quasar PG 1407+265, separated by 11 months. The data indicate two distinct states: a highly variable, bright state (first epoch); and a quiescent, low-flux one (second epoch). During the low-flux state the spectrum is consistent with a single, unabsorbed power law. However, during the brighter state a highly variable, steep component is statistically required. Contemporaneous ultraviolet data from the Optical Monitor allow an estimate of the optical-to-X-ray spectral index (α ox ), which appears typical of radio-quiet quasars during the low-flux state, but extremely flat during the high-flux state. The XMM-Newton data can be described as originating from a combination of jet and accretion disc processes, in which the (relativistic) X-ray jet only works intermittently. The scenario could help to describe some of the complexities seen in the broad-band spectral energy distribution of PG 1407+265, such as weak high-ionization emission lines, strong Fe II, unbeamed continuum and the weak radio emission relative to the optical.