MOSEL Survey: Tracking the Growth of Massive Galaxies at 2 < z < 4 Using Kinematics and the IllustrisTNG Simulation Academic Article uri icon

abstract

  • Abstract We use K-band spectroscopic data from the Multi-Object Spectroscopic Emission Line survey to analyze the kinematic properties of galaxies at z>3. Our sample consists of 34 galaxies at 3.0<z spec<3.8 between 9.0< <11.0. We find that galaxies with >10.2 at z>3 have 5621 km s1 lower integrated velocity dispersion compared to galaxies at z2 of similar stellar mass. Massive galaxies at z>3 have either a flat or declining star formation history (SFH), whereas similar stellar mass galaxies at z2.0 exhibit a slight peak in the past 500 Myr. Comparing with the IllustrisTNG cosmological simulation, we find that (i) the dynamical mass of massive galaxies in simulations ( > 10.0) increases by 0.1 dex at a fixed stellar mass between z=2.03.0, and (ii) dynamical mass growth is coupled with a rapid rise in the ex situ stellar mass fraction (stars accreted from other galaxies) for massive galaxies at z<3.5. We speculate that the rising contribution of ex situ stellar mass to the total stellar mass growth of massive galaxies is driving the higher integrated velocity dispersion and rising SFHs of massive galaxies at z2.0 compared to galaxies of similar stellar masses at z>3.

published proceedings

  • ASTROPHYSICAL JOURNAL

altmetric score

  • 218.516

author list (cited authors)

  • Gupta, A., Tran, K., Cohn, J., Alcorn, L. Y., Yuan, T., Rodriguez-Gomez, V., ... Cowley, M.

citation count

  • 4

complete list of authors

  • Gupta, Anshu||Tran, Kim-Vy||Cohn, Jonathan||Alcorn, Leo Y||Yuan, Tiantian||Rodriguez-Gomez, Vicente||Harshan, Anishya||Forrest, Ben||Kewley, Lisa J||Glazebrook, Karl||Straatman, Caroline M||Kacprzak, Glenn G||Nanayakkara, Themiya||Labbe, Ivo||Papovich, Casey||Cowley, Michael

publication date

  • April 2020