Extragalactic Background Light Inferred from AEGIS Galaxy SED-type Fractions
A. Dominguez, J. R. Primack, D. J. Rosario, F. Prada, R. C. Gilmore, S. M. Faber, D. C. Koo, R. S. Somerville, M. A. Perez-Torres, P. Perez-Gonzalez, J. -S. Hua… 展开作者
A. Dominguez, J. R. Primack, D. J. Rosario, F. Prada, R. C. Gilmore, S. M. Faber, D. C. Koo, R. S. Somerville, M. A. Perez-Torres, P. Perez-Gonzalez, J. -S. Huang, M. Davis, P. Guhathakurta, P. Barmby, C. J. Conselice, J. A. Newman, M. C. Cooper, M. Lozano
备注：
25 pages, 18 figures, 4 tables; accepted for publication in MNRAS on September 3, 2010. Online material available at http://side.iaa.es/EBL
河外背景光（EBL）对于理解星系演化的整个过程和伽马射线天文学都具有重要意义，但在0.1-1000微米之间的EBL光谱从未直接从星系光谱能量分布（SED）观测中确定。不断发展的，整体频谱的EBL是来自这里利用一种新的方法，仅基于观测。这是从观测到的静止坐标系K波段星系光度函数到红移4的演化（Cirasuolo et al. 2010），结合星系SED型分数的确定来实现的。这些都是基于拟合SWIRE模板的多波长样本约6000个星系的红移范围从0.2到1的全波长扩展Groth带国际巡天（AEGIS）。静止的星系，恒星形成的星系，星暴星系和活动星系核星系的红移范围内的变化分数的估计，和两个替代的外推的SED型更高的红移被认为是。这使得计算的光度密度的演变，从紫外线到红外线，不断变化的恒星形成率密度的宇宙，不断变化的贡献，从不同的星系群，包括活动星系核星系和EBL的积累的辐射热EBL。我们的EBL计算进行了比较，从一个半解析模型，从另一个基于观测的模型和观测数据。在我们的建模直接基于数据的EBL的不确定性进行了量化，并讨论了其后果非常高的能量伽马射线的衰减，由于对生产的EBL。它的结论是，EBL很好地限制从紫外到中红外，但独立的努力，从红外和伽马射线天文学，以减少在远红外的不确定性是必要的。
英文摘要：
The extragalactic background light (EBL) is of fundamental importance both for understanding the entire process of galaxy evolution and for gamma-ray astronomy, but the overall spectrum of the EBL between 0.1-1000 microns has never been determined directly from galaxy spectral energy distribution (SED) observations over a wide redshift range. The evolving, overall spectrum of the EBL is derived here utilizing a novel method based on observations only. This is achieved from the observed evolution of the rest-frame K-band galaxy luminosity function up to redshift 4 (Cirasuolo et al. 2010), combined with a determination of galaxy SED-type fractions. These are based on fitting SWIRE templates to a multiwavelength sample of about 6000 galaxies in the redshift range from 0.2 to 1 from the All-wavelength Extended Groth Strip International Survey (AEGIS). The changing fractions of quiescent galaxies, star-forming galaxies, starburst galaxies and AGN galaxies in that redshift range are estimated, and two alternative extrapolations of SED-types to higher redshifts are considered. This allows calculation of the evolution of the luminosity densities from the UV to the IR, the evolving star formation rate density of the universe, the evolving contribution to the bolometric EBL from the different galaxy populations including AGN galaxies and the buildup of the EBL. Our EBL calculations are compared with those from a semi-analytic model, from another observationally-based model and observational data. The EBL uncertainties in our modeling based directly on the data are quantified, and their consequences for attenuation of very high energy gamma-rays due to pair production on the EBL are discussed. It is concluded that the EBL is well constrained from the UV to the mid-IR, but independent efforts from infrared and gamma-ray astronomy are needed in order to reduce the uncertainties in the far-IR.
High-frequency-peaked BL Lacertae objects as spectral candles to measure the Extragalactic Background Light in the Fermi and air Cherenkov telescopes era
Deep Extragalactic VIsible Legacy Survey (DEVILS): First Data Release Covering The D10 (COSMOS) Region
ICRAR, The University of Western Australia（西澳大利亚大学）；Department of Physics & Astronomy, McMaster University（麦克马斯特大学）；Jodrell Bank Centre for Astrophysics, University of Manchester（曼彻斯特大学）；Australian Astronomical Optics, Macquarie University（麦考瑞大学）；School of Physics & Astronomy, Monash University（莫纳什大学）；Sydney Institute for Astronomy, School of Physics, A28, The University of Sydney（悉尼大学）；Astrophysics Group, School of Physics, University of Bristol（布里斯托大学）；Instituto de Astrofísica de Canarias（加那利天体物理研究所）；Departamento de Astrofísica, Universidad de La Laguna (ULL)（拉帕尔马大学）；Research School of Astronomy and Astrophysics, Australian National University（澳大利亚国立大学）
The NuSTAR Extragalactic Survey: A First Sensitive Look at the High-Energy Cosmic X-ray Background Population
We report on the first ten identifications of sources serendipitously detected by the NuSTAR to provide the first sensitive census of the cosmic X-ray background (CXB) source population at >10 keV. We find that these NuSTAR-detected sources are ~100x fainter than those previously detected at >10 keV and have a broad range in redshift and luminosity (z=0.020-2.923 and L_10-40 keV~4x10^{41}-5x10^{45} erg/s); the median redshift and luminosity are z~0.7 and L_10-40 keV~3x10^{44} erg/s, respectively. We characterize these sources on the basis of broad-band ~0.5-32 keV spectroscopy, optical spectro…
