A MUltiwavelength Study of ELAN Environments (AMUSE²)

Ubiquitous dusty star-forming galaxies associated with enormous Lyα nebulae on megaparsec scales

¹ Department of Physics, Colorado College, 14 E. Cache La Poudre Street, Colorado Springs, CO 80903, USA
² Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan
e-mail: ccchen@asiaa.sinica.edu.tw
³ Max-Planck-Institut fur Astrophysik, Karl-Schwarzschild-Str 1, 85748 Garching bei München, Germany
⁴ Dipartimento di Fisica G. Occhialini, Università degli Studi di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
⁵ Centre for Extragalactic Astronomy, Durham University, South Road, Durham DH1 3LE, UK
⁶ Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE, UK
⁷ Department of Astronomy, Tsinghua University, Beijing 100084, PR China
⁸ Dipartimento di Fisica e Astronomia, Università di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
⁹ INAF – Osservatorio Astrofisico di Arcetri, 50125 Florence, Italy
¹⁰ UCO/Lick Observatory, University of California, 2013 Santa Cruz, Santa Cruz, CA 95064, USA
¹¹ Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), 5-1-5 Kashiwanoha, Kashiwa 277-8583, Japan
¹² Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of Korea

Received: 15 December 2020
Accepted: 25 October 2021

Abstract

We have been undertaking a systematic survey at 850 μm based on a sample of four prototypical z ∼ 2 − 3 enormous Lyα nebulae (ELANe) as well as their megaparsec-scale (Mpc-scale) environments to study the physical connections between ELANe and their coeval dusty submillimeter galaxies (SMGs). By analysing the SCUBA-2 data with self-consistent Monte Carlo simulations to construct the number counts, here, we report on the overabundance of 850 μm-selected submillimeter sources around all the four ELANe, by a factor of 3.6 ± 0.6 (weighted average) compared to the blank fields. This suggests that the excessive number of submillimeter sources are likely to be part of the Mpc-scale environment around the ELANe, corroborating the co-evolution scenario for SMGs and quasars; this is a process which may be more commonly observed in the ELAN fields. If the current form of the underlying count models continues toward the fainter end, our results would suggest an excess of the 850 μm extragalactic background light by a factor of between 2–10, an indication of significant background light fluctuations on the survey scales. Finally, by assuming that all the excessive submillimeter sources are associated with their corresponding ELAN environments, we estimate the SFR densities of each ELAN field, as well as a weighted average of ΣSFR = 1200 ± 300 M_⊙ yr⁻¹ Mpc⁻³, consistent with that found in the vicinity of other quasar systems or proto-clusters at similar redshifts; in addition, it is a factor of about 300 greater than the cosmic mean.