A Quasar Shedding Its Dust Cocoon at Redshift 2

Weimin Yi, W. N. Brandt, Q. Ni, Luis C. Ho, Bin Luo, Wei Yan, D. P. Schneider, Jeremiah D. Paul, Richard M. Plotkin, Jinyi Yang, Feige Wang, Zhicheng He, Chen Chen, Xue Bing Wu, Jin Ming Bai

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4 Scopus citations


We present the first near-IR spectroscopy and joint analyses of multiwavelength observations for SDSS J082747.14+425241.1, a dust-reddened, weak broad emission-line quasar (WLQ) undergoing a remarkable broad-absorption line (BAL) transformation. The systemic redshift is more precisely measured to be z = 2.070 ± 0.001 using Hβ compared to z = 2.040 ± 0.003 using Mg ii from the literature, signifying an extreme Mg ii blueshift of 2140 ± 530 km s-1 relative to Hβ. Using the Hβ-based single-epoch scaling relation with a systematic uncertainty of 0.3 dex, its black hole (BH) mass and Eddington ratio are estimated to be M BH ∼6.1 × 108 M ⊙ and λ Edd ∼0.71, indicative of being in a rapidly accreting phase. Our investigations confirm the WLQ nature and the LoBAL → HiBAL transformation, along with a factor of 2 increase in the Mg ii+Fe ii emission strength and a decrease of 0.1 in E(B - V) over two decades. The kinetic power of this LoBAL wind at R ∼15 pc from its BH is estimated to be 1/443% of the Eddington luminosity, sufficient for quasar feedback upon its host galaxy albeit with an order-of-magnitude uncertainty. This quasar provides a clear example of the long-sought scenario where LoBAL quasars are surrounded by dust cocoons, and wide-angle nuclear winds play a key role in the transition of red quasars evolving into the commonly seen blue quasars.

Original languageEnglish (US)
Article number5
JournalAstrophysical Journal
Issue number1
StatePublished - May 1 2022

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


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