The molecular-gas properties in the gravitationally lensed merger HATLAS J142935.3-002836

Messias, Hugo; Nagar, Neil; Zhang, Zhi-Yu; Oteo, Iv�n; Dye, Simon; Ibar, Eduardo; Timmons, Nicholas; Van Der Werf, Paul; Riechers, Dominik; Eales, Stephen; Ivison, Rob; Maresca, Jacob; Michalowski, J.; Yang, Chentao

Abstract

Follow-up observations of (sub-)mm-selected gravitationally-lensed systems have allowed a more detailed study of the dust-enshrouded phase of star-formation up to very early cosmic times. Here, the case of the gravitationally lensed merger in HATLAS J142935.3-002836 (also known as H1429-0028; z_lens=0.218, z_bkg=1.027) is revisited following recent developments in the literature and new APEX observations targeting two carbon monoxide (CO) rotational transitions J_up=3 and 6. We show that the line-profiles comprise three distinct velocity components, where the fainter high-velocity one is less magnified and more compact. The modelling of the observed spectral line energy distribution of CO J_up=2 to 6 and [CI]3P_1-3P_0 assumes a large velocity gradient scenario, where the analysis is based on four statistical approaches. Since the detected gas and dust emission comes exclusively from only one of the two merging components (the one oriented North-South, NS), we are only able to determine upper-limits for the companion. The molecular gas in the NS component in H1429-0028 is found to have a temperature of ~70K, a volume density of log(n[/cm3])~3.7, to be expanding at ~10km/s/pc, and amounts to M_H2=4(-2,+3)*1e9 Msun. The CO to H2 conversion factor is estimated to be alpha_CO=0.4(-0.2,+0.3) Msun/(K.km/s.pc2). The NS galaxy is expected to have a factor of >10x more gas than its companion (M_H2

Citation

Messias, H., Nagar, N., Zhang, Z.-Y., Oteo, I., Dye, S., Ibar, E., Timmons, N., Van Der Werf, P., Riechers, D., Eales, S., Ivison, R., Maresca, J., Michalowski, J., & Yang, C. (2019). The molecular-gas properties in the gravitationally lensed merger HATLAS J142935.3-002836. Monthly Notices of the Royal Astronomical Society, 486(2), 2366-2378. https://doi.org/10.1093/mnras/stz945

• Journal Article Type: Article
• Acceptance Date: Mar 28, 2019
• Online Publication Date: Apr 18, 2019
• Publication Date: 2019-06
• Deposit Date: Apr 18, 2019
• Publicly Available Date: Apr 25, 2019
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 486
• Issue: 2
• Pages: 2366-2378
• DOI: https://doi.org/10.1093/mnras/stz945
• Keywords: Gravitational lensing: strong; Galaxies: interactions; Submillimeter: galaxies; Submillimeter: ISM; Abundances
• Public URL: https://nottingham-repository.worktribe.com/output/1829658
• Publisher URL: https://academic.oup.com/mnras/article/486/2/2366/5475133
• Additional Information: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2019 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved
• Contract Date: Apr 25, 2019