论文标题
新的高红色高速果胶ulas j0816+2134 Z = 7.46
Dense nitrogen-enriched circumnuclear region of the new high-redshift quasar ULAS J0816+2134 at z=7.46
论文作者
论文摘要
我们介绍了新的高还原速度类星体ULAS J081621.47+213442.6的0.85-2.5微米发现谱和多上述光度法，该频谱使用Gemini North的GNIRS光谱仪获得了4-Mukirt Telescopes的近红外宽视野相机。 Ulas J081621.47+213442.6的红移从MGII 2799发射线测量为z = 7.461。类星体的绝对大小为M1450 = -25.33。使用MGII 2799线和Eddington积聚率估计的黑洞质量为〜5x10^8msun和〜0.7。 The spectrum of ULAS J081621.47+213442.6 exhibits strong NIII] 1750 emission line of a rest-frame equivalent width of ~12.5 A. The high abundance of nitrogen suggests that ULAS J081621.47+213442.6 may be at the peak of the nitrogen enrichment of the circumnuclear region by the asymptotic giant branch stars,大部分恒星形成后预期的〜0.25 Gyr。高氮丰度所隐含的Ulas J081621.47+213442.6的Starburst的年龄表明，类星体黑洞的活性相位可能仅持续〜0.25 Gyr，有利于大量的初始黑洞。我们还观察到ULAS J081621.47+213442.6的UV连续体的通量变化是由左右的吸收柱密度变化在〜47 d的静止框架上的变化引起的。负责此变化的气云的估计氢柱密度为N〜10^{23.5} cm^{ - 2}，与大多数是中性的，重力界面的典型柱密度一致。
We present the 0.85-2.5-micron discovery spectrum and multi-epoch photometry of the new high-redshift quasar ULAS J081621.47+213442.6 obtained using the GNIRS spectrograph of the Gemini North and near-infrared wide-field camera of the 4-m UKIRT telescopes. The redshift of ULAS J081621.47+213442.6 measured from the MgII 2799 emission line is z=7.461. The absolute magnitude of the quasar is M1450=-25.33. The black hole mass estimated using the MgII 2799 line and Eddington accretion rate are ~5x10^8Msun and ~0.7. The spectrum of ULAS J081621.47+213442.6 exhibits strong NIII] 1750 emission line of a rest-frame equivalent width of ~12.5 A. The high abundance of nitrogen suggests that ULAS J081621.47+213442.6 may be at the peak of the nitrogen enrichment of the circumnuclear region by the asymptotic giant branch stars, which is expected ~0.25 Gyr after the bulk of star formation. The age of the starburst of ULAS J081621.47+213442.6 implied by the high nitrogen abundance, indicates that the active phase of the black hole growth of the quasar may have lasted only ~0.25 Gyr, favoring a massive initial black hole seed. We also observed the flux variations of the UV continuum of ULAS J081621.47+213442.6 caused by the variation in the line-of-sight absorbing column density on a rest-frame timescale of ~47 d. The estimated hydrogen column density of the gas cloud responsible for this variation is N~10^{23.5} cm^{-2}, consistent with the typical column density of mostly neutral, gravitationally bound clouds of the broad line region of quasars.
