Dust and Cold Gas Properties of Starburst HyLIRG Quasars at z ∼ 2.5
Artikel i vetenskaplig tidskrift, 2024

Some high-z active galactic nuclei (AGNs) are found to reside in extreme star-forming galaxies, such as hyperluminous infrared galaxies (HyLIRGs), with AGN-removed L IR of >1013 L ⊙. In this paper, we report NOEMA observations of six apparent starburst HyLIRGs associated with optical quasars at z ∼ 2-3 in the Stripe 82 field, to study their dust and molecular CO properties. Five out of the six candidates are detected with CO(4-3) or CO(5-4) emission, and four in the 2 mm dust continuum. Based on the linewidth- L CO ( 1 − 0 ) ′ diagnostics, we find that four galaxies are likely unlensed or weakly lensed sources. The molecular gas mass is in the range of μ M H 2 ∼ 0.8 - 9.7 × 10 10 M ⊙ (with α = 0.8 M ⊙ K km s − 1 pc 2 − 1 , where μ is the unknown possible gravitational magnification factor). We fit their spectral energy distributions, after including the observed 2 mm fluxes and upper limits, and estimate their apparent (uncorrected for possible lensing effects) star formation rates (μSFRs) to be ∼400-2500 M ⊙ yr−1, with a depletion time of ∼20-110 Myr. We notice interesting offsets, of ∼10-40 kpc spatially or ∼1000-2000 km s−1 spectroscopically, between the optical quasar and the millimeter continuum or CO emissions. The observed velocity shift is likely related to the blueshifted broad-emission-line region of quasars, though mergers or recoiling black holes are also possible causes, which can explain the spatial offsets and the high intrinsic star formation rates in the HyLIRG quasar systems.

Författare

Feng Yuan Liu

Chinese Academy of Sciences

University of Edinburgh

Y. Sophia Dai

Chinese Academy of Sciences

A.A. Omont

Institut d 'Astrophysique de Paris

Daizhong Liu

Max-Planck-Gesellschaft

P. Cox

Institut d 'Astrophysique de Paris

R. Neri

Institut de Radioastronomie Millimétrique (IRAM)

M. Krips

Institut de Radioastronomie Millimétrique (IRAM)

Chentao Yang

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

Xue Bing Wu

Beijing University of Technology

Jia Sheng Huang

Chinese Academy of Sciences

Harvard-Smithsonian Center for Astrophysics

Astrophysical Journal

0004-637X (ISSN) 1538-4357 (eISSN)

Vol. 964 2 136

Exploring the Hidden Dusty Nuclei of Galaxies (HIDDeN)

Europeiska forskningsrådet (ERC) (789410), 2018-10-01 -- 2023-09-30.

Ämneskategorier

Astronomi, astrofysik och kosmologi

DOI

10.3847/1538-4357/ad24fe

Mer information

Senast uppdaterat

2024-04-08