Full description
We present stellar specific angular momentum j* measurements of two z ˜ 1.5 galaxies in the KGES sample and 12 DYNAMO z ˜ 0.1 analogues of high-redshift galaxies. We combine natural seeing integral field spectroscopic data to trace line emission out to high multiples of effective radius re, with adaptive optics assisted Keck/OSIRIS observations to trace the rapid rise in rotation curve in the inner regions. Our spaxel-wise integration method gives results that are on average within measurement uncertainty of the traditional rotation curve model method. At z ˜ 0, combining GMOS and OSIRIS data sets improves the measurement uncertainty in j* from 13 per cent (GMOS only) or 16 per cent (OSIRIS only) to 10 per cent. At z ˜ 1.5, systematics allow for at best 20 per cent uncertainty on j*. DYNAMO analogues of high-z galaxies have low j* for their stellar mass M*, and low bulge-to-total light ratio β for their j*/M*. The high-z galaxy COSMOS 127977 has j*/M* consistent with normal local disc galaxies, while UDS 78317 is consistent with local analogues. However, our high-resolution OSIRIS data reveal that UDS 78317 may be a merging system. We report a relationship between distance to the β-j*/M* plane and the ratio of velocity dispersion to rotational velocity σ/vmax, where galaxies that deviate more from the plane are more dispersion-dominated due to turbulence. Much of the scatter in M*-j* that is not explained by variations in the bulge-to-total ratio or evolution with redshift may be driven by increased turbulence due to star formation, or by treating mergers as rotating discs.Notes
External OrganisationsSwinburne University of Technology; ARC Centre of Excellence for All-sky Astrophysics; ARC Centre of Excellence for Astrophysics in Three Dimensions (ASTRO3D); Durham University; Max Planck Institute for Radio Astronomy
Associated Persons
Sarah M. Sweet (Creator); Deanne B. Fisher (Creator); Giulia Savorgnan (Creator); Karl Glazebrook (Creator); Steven Gillman (Creator); A. Mark Swinbank (Creator); Richard G. Bower (Creator); Ray M. Sharples (Creator)
Sarah M. Sweet (Creator); Deanne B. Fisher (Creator); Giulia Savorgnan (Creator); Karl Glazebrook (Creator); Steven Gillman (Creator); A. Mark Swinbank (Creator); Richard G. Bower (Creator); Ray M. Sharples (Creator)
Created: 2019-03-14 to 2019-03-14
Issued: 2019-06
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Identifiers
- DOI : 10.1093/MNRAS/STZ750
- global : f3656acb-2cb9-41f1-b6f3-23975e94a17f