论文标题
BL LAC对象的光谱：TEV候选人
Optical spectroscopy of BL Lac objects: TeV candidates
论文作者
论文摘要
我们研究了第三个硬fermi-lat源（3FHL）的第三个目录中检测到的伽马射线源的光谱光学特性，其高于50 GEV，并且作为TEV发射器的良好候选者。我们关注的是由费米团队标记为BL LAC对象（BLL）或不确定类型的Blazar候选者（BCU）的91个来源，它们在北半球，并且具有未知或不确定的红移。我们在此处报告13 BCU和42 BLL的GTC光谱（4100-7750 AA的光谱范围内）。我们能够将观察到的目标分类为BLL，并简要讨论每个源。这些光谱使我们能够根据发射和/或吸收线确定25个物体的红移，发现0.05 <z <0.91。检测到的大多数发射线是由于[O III]和[N II]的禁止过渡。发现观察到的线光度低于类似连续体处的QSO的亮度，如果假定明显的光束因子，则可以与QSO的线 - 凸线亮度关系进行调和。此外，对于5个来源，我们发现了介入的吸收线，可以设置红移的光谱下限。对于光谱无线的其余25个来源，假设宿主星系是巨大的椭圆形，则给出了z的下限。
We investigate the spectroscopic optical properties of gamma-ray sources detected with high significance above 50 GeV in the Third Catalog of Hard Fermi-LAT Sources (3FHL) and that are good candidates as TeV emitters. We focus on the 91 sources that are labelled by the Fermi team as BL Lac objects (BLL) or Blazar candidates of uncertain type (BCU) , that are in the Northern hemisphere, and are with unknown or uncertain redshift. We report here on GTC spectra (in the spectral range 4100 - 7750 AA) of 13 BCU and 42 BLL. We are able to classify the observed targets as BLL and each source is briefly discussed. The spectra allowed us to determine the redshift of 25 objects on the basis of emission and/or absorption lines, finding 0.05 < z < 0.91. Most of the emission lines detected are due to forbidden transition of [O III] and [N II]. The observed line luminosity is found lower than that of QSOs at similar continuum and could be reconciled with the line-continuum luminosity relationship of QSOs if a significant beaming factor is assumed. Moreover for 5 sources we found intervening absorption lines that allows to set a spectroscopic lower limit of the redshift. For the remaining 25 sources, for which the spectra are lineless, a lower limit to z is given, assuming that the host galaxies are giant ellipticals.
