A Diverse Population of z ∼ 2 ULIRGs Revealed by JWST Imaging

Autor: J.-S. Huang, Zi-Jian Li, Cheng Cheng, Meicun Hou, Haojing Yan, S. P. Willner, Y.-S. Dai, X. Z. Zheng, J. Pan, D. Rigopoulou, T. Wang, Zhiyuan Li, Piaoran Liang, A. Esamdin, G. G. Fazio
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: The Astrophysical Journal, Vol 949, Iss 2, p 83 (2023)
Druh dokumentu: article
ISSN: 1538-4357
DOI: 10.3847/1538-4357/acc9c3
Popis: Four ultraluminous infrared galaxies (ULIRGs) observed with JWST/NIRcam in the Cosmos Evolution Early Release Science program offer an unbiased preview of the z ∼ 2 ULIRG population. The objects were originally selected at 24 μ m and have strong polycyclic aromatic hydrocarbon emission features observed with Spitzer/Infrared Spectrometer. The four objects have similar stellar masses of ∼10 ^11 M _⊙ but otherwise are quite diverse. One is an isolated disk galaxy, but it has an active nucleus as shown by X-ray observations and by a bright point-source nucleus. Two others are merging pairs with mass ratios of 6–7:1. One has active nuclei in both components, while the other has only one active nucleus: the one in the less-massive neighbor, not the ULIRG. The fourth object is clumpy and irregular and is probably a merger, but there is no sign of an active nucleus. The intrinsic spectral energy distributions for the four active galactic nuclei in these systems are typical of type-2 QSOs. This study is consistent with the idea that even if internal processes can produce large luminosities at z ∼ 2, galaxy merging may still be necessary for the most luminous objects. The diversity of these four initial examples suggests that large samples will be needed to understand the z ∼ 2 ULIRG population.
Databáze: Directory of Open Access Journals