18 research outputs found

    The SAMI Galaxy Survey: The cluster redshift survey, target selection and cluster properties

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    We describe the selection of galaxies targeted in eight low redshift clusters (APMCC0917, A168, A4038, EDCC442, A3880, A2399, A119 and A85; 0.029<z<0.0580.029 < z < 0.058) as part of the Sydney-AAO Multi-Object integral field Spectrograph Galaxy Survey (SAMI-GS). We have conducted a redshift survey of these clusters using the AAOmega multi-object spectrograph on the 3.9m Anglo-Australian Telescope. The redshift survey is used to determine cluster membership and to characterise the dynamical properties of the clusters. In combination with existing data, the survey resulted in 21,257 reliable redshift measurements and 2899 confirmed cluster member galaxies. Our redshift catalogue has a high spectroscopic completeness (94%\sim 94\%) for rpetro19.4r_{\rm petro} \leq 19.4 and clustercentric distances R<2R200R< 2\rm{R}_{200}. We use the confirmed cluster member positions and redshifts to determine cluster velocity dispersion, R200\rm{R}_{200}, virial and caustic masses, as well as cluster structure. The clusters have virial masses 14.25log(M200/M)15.1914.25 \leq {\rm log }({\rm M}_{200}/\rm{M}_{\odot}) \leq 15.19. The cluster sample exhibits a range of dynamical states, from relatively relaxed-appearing systems, to clusters with strong indications of merger-related substructure. Aperture- and PSF-matched photometry are derived from SDSS and VST/ATLAS imaging and used to estimate stellar masses. These estimates, in combination with the redshifts, are used to define the input target catalogue for the cluster portion of the SAMI-GS. The primary SAMI-GS cluster targets have R<R200R< \rm{R}_{200}, velocities vpec<3.5σ200|v_{\rm pec}| < 3.5\sigma_{200} and stellar masses 9.5log(Mapprox/M)129.5 \leq {\rm log(M}^*_{approx}/\rm{M}_{\odot}) \leq 12. Finally, we give an update on the SAMI-GS progress for the cluster regions

    Know Thy Selves: Learning to Understand Oneself Increases the Ability to Understand Others

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    Understanding others’ feelings, intentions, and beliefs is a crucial social skill both for our personal lives and for meeting the challenges of a globalized world. Recent evidence suggests that the ability to represent and infer others’ mental states (Theory of Mind, ToM) can be enhanced by mental training in healthy adults. The present study investigated the role of training-induced understanding of oneself for the enhanced understanding of others. In a large-scale longitudinal study, two independent participant samples (N = 80 and N = 81) received a 3-month contemplative training. This training focused on perspective taking and was inspired by the Internal Family Systems model that conceives the self as being composed of a complex system of inner personality aspects. Specifically, participants practiced perspective taking on their own inner states by learning to identify and classify different inner personality parts. Results revealed that the degree to which participants improved their understanding of themselves—reflected in the number of different inner parts they could identify—predicted their improvements in high-level ToM performance over training. Especially the number of identified parts that were negatively valenced showed a strong relation with enhanced ToM capacities. This finding suggests a close link between getting better in understanding oneself and improvement in social intelligence

    The SAMI Pilot Survey: Stellar kinematics of galaxies in Abell 85, 168 and 2399

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    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
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