Optical Luminosity Function of the QSOs Observed with the Sloan Digital Sky Survey Data Release Seven (SDSS DR7)

• 作者: Irom Ablu Meitei Kangujam Yugindro Singh Salam Ajitkumar Singh
• 来源期刊: 天文学与天体物理学国际期刊(英文)
• 学科: 地球科学
• 关键词: Quasi STELLAR Objects (QSOs) LUMINOSITY Function
• 年，卷（期）: 2014,（3）
• 页码范围: 474-478
• 页数: 5页
• 分类号: P1

摘要

We have determined the Optical Luminosity Function (OLF) of a sample of 80946 Quasi Stellar Objects (QSOs) taken from the Sloan Digital Sky Survey Data Release Seven (SDSS DR7) with redshift range??0.3 z Mi < -22.5. The Monte Carlo Technique of numerical integration is used. The sample of QSOs is divided into seven sub-samples with redshift in the ranges: 0.30 z z z < 1.05,?1.05 z z z < 1.80, and 1.80 z < 2.05. Each redshift interval is binned in absolute magnitude with bin width ΔMi = -0.5. A flat universe with cosmological parameters Ωm = 0.3, Ω∧ = 0.7, and Hubble constant Ho = 70.0 km·s-1·Mpc-1 is used. From the optical luminosity function a clear evidence of AGN downsizing is observed, i.e. the number density of the less luminous AGNs peaks at lower redshift than the number density of the more luminous AGNs.