Manuscript received October 2, 2025; accepted December 7, 2025; published February 5, 2026.
Abstract—We present the work using the high-quality optically-selected quasar catalogue from the Sloan Digital Sky Survey (SDSS) to select a large sample of Weak Emission Line Quasars (WELQs). The Equivalent Widths (EWs) of their emission lines are on the weaker end of the spectrum for Active Galactic Nuclei (AGNs). Yet, their bolometric luminosity distribution is similar to that of Normal Emission Line Quasars (NELQs). By integrating data from multiple wavelength bands, including the ultraviolet data from the Galaxy Evolution Explorer (GALEX), the near-infrared data from the United Kingdom Infrared Telescope Deep Sky Survey (UKIDSS), the mid-infrared data from the Wide-field Infrared Survey Explorer (WISE), and the far-infrared images from the Herschel Space Telescope, we conducted a comprehensive study on the Spectral Energy Distribution (SED) of WELQs across ultraviolet, optical, near-infrared, mid-infrared, and far-infrared bands. Our research indicates that within the redshift range of "1<z<3" , the average far-infrared luminosity of WELQs is approximately 5-10 times higher than that of normal quasars, with no significant evolution with redshift. This suggests that WELQs may be characterised by intense star formation activities in their host galaxies, heating the surrounding dust, and potentially being in an early evolutionary stage of AGNs. The underdeveloped Broad Emission Line Region (BELR) and Narrow Emission Line Region (NELR) might contribute to their weak emission lines. Further data processing and upcoming survey projects are expected to unveil the physical origins of WELQs, enhancing our understanding of the formation and evolution of quasars and AGNs.
Keywords—Weak Emission Line Quasars (WELQs), spectral energy distribution, active galactic nuclei
Cite: Zile Zeng, "Dust Emission and Star Formation Activities of High Redshift Weak Emission Line Quasars," International Journal of Engineering and Technology, vol. 18, no. 1, pp. 1-14, 2026.
Copyright © 2026 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (
CC BY 4.0).
