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arXiv · 0708.0835

Rest-Frame Ultraviolet to Near Infrared Observations of an Interacting Lyman Break Galaxy at z = 4.42

Joshua D. Younger·Jia-Sheng Huang·Giovanni G. Fazio·Thomas J. Cox·Kamson Lai·Philip F. Hopkins·Lars Hernquist·Casey J. Papovich·Luc Simard·Lihwai Lin·Yi-Wen Cheng·Haojin Yan·Dusan Keres·Alice E. Shapley
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Abstract

We present the rest-frame ultraviolet through near infrared spectral energy distribution for an interacting Lyman break galaxy at a redshift z=4.42, the highest redshift merging system known with clearly resolved tidal features. The two objects in this system - HDF-G4 and its previously unidentified companion - are both B_{435} band dropouts, have similar V_{606}-i_{775} and i_{775}-z_{850} colors, and are separated by 1", which at z=4.42 corresponds to 7 kpc projected nuclear separation; all indicative of an interacting system. Fits to stellar population models indicate a stellar mass of M_\star = 2.6\times 10^{10} M_\odot, age of \tau_\star = 720 My, and exponential star formation history with an e-folding time \tau_0 = 440 My. Using these derived stellar populations as constraints, we model the HDF-G4 system using hydrodynamical simulations, and find that it will likely evolve into a quasar by z\sim3.5, and a quiescent, compact spheroid by z\sim 2.5 similar to those observed at z > 2. And, the existence of such an object supports galaxy formation models in which major mergers drive the high redshift buildup of spheroids and black holes.

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Joshua D. Younger, Jia-Sheng Huang, Giovanni G. Fazio, Thomas J. Cox, Kamson Lai, Philip F. Hopkins, Lars Hernquist, Casey J. Papovich, Luc Simard, Lihwai Lin, Yi-Wen Cheng, Haojin Yan, Dusan Keres, Alice E. Shapley. 2007-08-07. Rest-Frame Ultraviolet to Near Infrared Observations of an Interacting Lyman Break Galaxy at z = 4.42. https://doi.org/10.1086/522773

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