TY - JOUR
T1 - The SAMI Pilot Survey
T2 - stellar kinematics of galaxies in Abell 85, 168 and 2399
AU - Fogarty, Lisa M R
AU - Scott, N.
AU - Owers, Matt S.
AU - Croom, Scott Martin
AU - Bekki, K
AU - Houghton, Ryan C W
AU - van de Sande, J.
AU - D'Eugenio, F.
AU - Cecil, Gerald N
AU - Colless, Matthew Malcolm
AU - Bland-Hawthorn, Joss
AU - Brough, Sarah
AU - Cortese, Luca
AU - Davies, R. L.
AU - Jones, D. H.
AU - Pracy, Michael B
AU - Allen, J. T.
AU - Bryant, J. J.
AU - Goodwin, M.
AU - Green, A. W.
AU - Konstantopoulos, Iraklis S
AU - Lawrence, J. S.
AU - Lorente, N. P.F.
AU - Richards, S.
AU - Sharp, Robert G
PY - 2015
Y1 - 2015
N2 - We present the SAMI Pilot Survey, consisting of integral field spectroscopy of 106 galaxies across three galaxy clusters, Abell 85, Abell 168 and Abell 2399. The galaxies were selected by absolute magnitude to have Mr < -20.25 mag. The survey, using the Sydney-AAO Multi-object Integral field spectrograph (SAMI), comprises observations of galaxies of all morphological types with 75 per cent of the sample being early-type galaxies (ETGs) and 25 per cent being late-type galaxies (LTGs). Stellar velocity and velocity dispersion maps are derived for all 106 galaxies in the sample. The λR parameter, a proxy for the specific stellar angular momentum, is calculated for each galaxy in the sample. We find a trend between λR and galaxy concentration such that LTGs are less concentrated higher angular momentum systems, with the fast-rotating ETGs (FRs) more concentrated and lower in angular momentum. This suggests that some dynamical processes are involved in transforming LTGs to FRs, though a significant overlap between the λR distributions of these classes of galaxies implies that this is just one piece of a more complicated picture. We measure the kinematic misalignment angle, ψ, for the ETGs in the sample, to probe the intrinsic shapes of the galaxies. We find the majority of FRs (83 per cent) to be aligned, consistent with them being oblate spheroids (i.e. discs). The slow rotating ETGs (SRs), on the other hand, are significantly more likely to show kinematic misalignment (only 38 per cent are aligned). This confirms previous results that SRs are likely to be mildly triaxial systems.
AB - We present the SAMI Pilot Survey, consisting of integral field spectroscopy of 106 galaxies across three galaxy clusters, Abell 85, Abell 168 and Abell 2399. The galaxies were selected by absolute magnitude to have Mr < -20.25 mag. The survey, using the Sydney-AAO Multi-object Integral field spectrograph (SAMI), comprises observations of galaxies of all morphological types with 75 per cent of the sample being early-type galaxies (ETGs) and 25 per cent being late-type galaxies (LTGs). Stellar velocity and velocity dispersion maps are derived for all 106 galaxies in the sample. The λR parameter, a proxy for the specific stellar angular momentum, is calculated for each galaxy in the sample. We find a trend between λR and galaxy concentration such that LTGs are less concentrated higher angular momentum systems, with the fast-rotating ETGs (FRs) more concentrated and lower in angular momentum. This suggests that some dynamical processes are involved in transforming LTGs to FRs, though a significant overlap between the λR distributions of these classes of galaxies implies that this is just one piece of a more complicated picture. We measure the kinematic misalignment angle, ψ, for the ETGs in the sample, to probe the intrinsic shapes of the galaxies. We find the majority of FRs (83 per cent) to be aligned, consistent with them being oblate spheroids (i.e. discs). The slow rotating ETGs (SRs), on the other hand, are significantly more likely to show kinematic misalignment (only 38 per cent are aligned). This confirms previous results that SRs are likely to be mildly triaxial systems.
KW - Galaxies: kinematics and dynamics
KW - Techniques: imaging spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=84975686855&partnerID=8YFLogxK
U2 - 10.1093/mnras/stv2060
DO - 10.1093/mnras/stv2060
M3 - Article
AN - SCOPUS:84975686855
SN - 0035-8711
VL - 454
SP - 2050
EP - 2066
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 2
ER -