Details

Autor(en) / Beteiligte

• Simons, Raymond C.
• Kassin, Susan A.
• Trump, Jonathan R.
• Weiner, Benjamin J.
• Heckman, Timothy M.
• Barro, Guillermo
• Koo, David C.
• Guo, Yicheng
• Pacifici, Camilla
• Koekemoer, Anton
• Stephens, Andrew W.

Titel

KINEMATIC DOWNSIZING AT z ∼ 2

Ist Teil von

• The Astrophysical journal, 2016-10, Vol.830 (1), p.14

Ort / Verlag

Philadelphia: The American Astronomical Society

Erscheinungsjahr

2016

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• ABSTRACT We present results from a survey of the internal kinematics of 49 star-forming galaxies at in the CANDELS fields with the Keck/MOSFIRE spectrograph, Survey in the near-Infrared of Galaxies with Multiple position Angles (SIGMA). Kinematics (rotation velocity Vrot and gas velocity dispersion ) are measured from nebular emission lines which trace the hot ionized gas surrounding star-forming regions. We find that by , massive star-forming galaxies ( ) have assembled primitive disks: their kinematics are dominated by rotation, they are consistent with a marginally stable disk model, and they form a Tully-Fisher relation. These massive galaxies have values of that are factors of 2-5 lower than local well-ordered galaxies at similar masses. Such results are consistent with findings by other studies. We find that low-mass galaxies ( ) at this epoch are still in the early stages of disk assembly: their kinematics are often dominated by gas velocity dispersion and they fall from the Tully-Fisher relation to significantly low values of Vrot. This "kinematic downsizing" implies that the process(es) responsible for disrupting disks at have a stronger effect and/or are more active in low-mass systems. In conclusion, we find that the period of rapid stellar mass growth at is coincident with the nascent assembly of low-mass disks and the assembly and settling of high-mass disks.