Journal article
Luminous Mid-IR Selected Type-2 Quasars at Cosmic Noon in SDSS Stripe82 I: Selection, Composite Photometry, and Spectral Energy Distributions
Monthly notices of the Royal Astronomical Society, v 539(2), pp 1562-1594
09 Apr 2025
Abstract
We analyze 23 spectroscopically confirmed Type-2 quasars (QSOs) selected from WISE 22$\hbox{$\mu $m}$ band in the SDSS Stripe 82 region, focusing on their multi-band photometry and spectral energy distributions (SEDs). The 24 candidates were selected to be IR-luminous ($\rm flux_{W4} > 5mJy$), optically faint (r > 23) or with red color (r − W4 > 8.38). Gemini/GNIRS and Keck/LRIS observations confirm 23 to be Type-2 QSOs at z = 0.88 − 3.49. Multi-band photometry are used for SED fitting, covering 0.1$\rm \mu$m to 10$\rm \mu$m in the rest frame. The IR emission is dominated by the dust torus, with an average luminosity of $L_{\rm torus} = 10^{46.84} \rm erg\, s^{-1}$. We present three possibilities for the origin of the rest-UV/optical: scattered light, stellar emission, and the reddened accretion disk. Assuming an obscured:unobscured ratio of 1:1, the targets have bolometric luminosities of $L_{\rm bol} = 10^{46.28} - 10^{48.08} \rm erg\, s^{-1}$ and SMBH masses of $\rm 10^{8.18} {\rm M}_{\odot } - 10^{9.98} {\rm M}_{\odot }$, averaging $L_{\rm bol} = 10^{47.04}~{\rm {erg/s}}$ and $M_{\rm BH} = 10^{8.94} \rm {\rm M}_{\odot }$, assuming the Eddington limit. Compared to previous Type-2 AGN SEDs, our targets have a brighter dust torus and redder optical-IR color. By comparing the SED to JWST ‘little red dots’ (LRDs), we find that these IR-selected Type-2 QSOs have similar SED shapes to the LRDs. This survey demonstrates mid-IR selection as an efficient method to find luminous Type-2 QSOs and the composite photometry generated by this sample provide a guide for finding more Type-2 QSOs at higher redshift in the future.
Metrics
3 Record Views
Details
- Title
- Luminous Mid-IR Selected Type-2 Quasars at Cosmic Noon in SDSS Stripe82 I: Selection, Composite Photometry, and Spectral Energy Distributions
- Creators
- Ben Wang (Corresponding Author) - Tsinghua UniversityJoseph F Hennawi - Leiden UniversityZheng Cai - Tsinghua UniversityGordon T Richards - Drexel UniversityJan-Torge SchindlerNadia L Zakamska - Johns Hopkins UniversityYuzo Ishikawa - Johns Hopkins UniversityHollis B Akins - The University of Texas at AustinZechang Sun - Tsinghua University
- Publication Details
- Monthly notices of the Royal Astronomical Society, v 539(2), pp 1562-1594
- Publisher
- Oxford University Press
- Number of pages
- 33
- Grant note
- National Key Research and Development Program of China: 2023YFA1605600 National Key Research and Development Program of China: 12073014 National Science Foundation of China: CMS-CSST-2021-A05 China Manned Space Project: 20223080023 Tsinghua Initiative Scientific Research Program
BW and ZC were supported by the National Key Research and Development Program of China (grant no. 2023YFA1605600), the National Science Foundation of China (grant no. 12073014), the science research grants from the China Manned Space Project with no. CMS-CSST-2021-A05, and Tsinghua Initiative Scientific Research Program (no. 20223080023).
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Physics
- Web of Science ID
- WOS:001473030400001
- Scopus ID
- 2-s2.0-105003692384
- Other Identifier
- 991022048372804721
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Collaboration types
- Domestic collaboration
- International collaboration
- Web of Science research areas
- Astronomy & Astrophysics