中文

高红移弱线类星体:极高的吸积率还是贫血的宽线区?

宇宙学与河外天体物理 2015-05-19 v1

摘要

我们展示了高红移类星体中具有异常弱静止系紫外发射线的两个代表性成员(WLQs)——红移z=3.55的SDSS J114153.34+021924.3和红移z=3.49的SDSS J123743.08+630144.9——的Gemini-North K波段光谱。在两个源中,我们都探测到异常弱的宽H_beta线,并对其[O III]线的强度设定了严格的上限。基于维里定理和H_beta线的黑洞质量测定表明,这些源的归一化吸积率为L/L_Edd=0.4,这完全在具有相似光度和红移的典型类星体观测范围内。我们还展示了SDSS J114153.34+021924.3的高质量XMM-Newton成像光谱,发现其硬X射线光子指数为Gamma=1.91^{+0.24}_{-0.22},这支持了该源的维里L/L_Edd测定。我们的结果表明,WLQs中宽发射线的弱化并非源于极端连续发射源,而是由于异常的宽发射线区性质。

关键词

引用

@article{arxiv.1009.2091,
  title  = {Weak-Line Quasars at High Redshift: Extremely High Accretion Rates or Anemic Broad-Line Regions?},
  author = {Ohad Shemmer and Benny Trakhtenbrot and Scott F. Anderson and W. N. Brandt and Aleksandar M. Diamond-Stanic and Xiaohui Fan and Paulina Lira and Hagai Netzer and Richard M. Plotkin and Gordon T. Richards and Donald P. Schneider and Michael A. Strauss},
  journal= {arXiv preprint arXiv:1009.2091},
  year   = {2015}
}

备注

5 pages (emulateapj), 3 figures. Accepted for publication in ApJ Letters