Galaxy And Mass Assembly (GAMA): end of survey report and data release 2

117

131

Section: Datamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Galaxy And Mass Assembly (GAMA): $\mathcal {M_\star }\text{--}R_{\rm e}$ relations ofz= 0 bulges, discs and spheroids

Lange

Moffett

Driver

et al. 2016

117

131

“…GAMA provides a high level of spectroscopic completeness (98.5% in the regions from which SAMI targets were drawn; Liske et al 2015), providing spectroscopy of targets 2 magnitudes deeper than the SDSS. Within the GAMA survey regions there is a large volume of complementary multi-wavelength data available, including radio continuum (NVSS; Condon et al 1998, FIRST;Becker, White, & Helfand 1995) and emission line data (HIPASS; Barnes et al 2001), infrared (UKIDSS; Lawrence et al 2007) and ultraviolet (GALEX ;Liske et al 2015) photometry, in addition to the SDSS and GAMA optical imaging, photometry and spectroscopy. The SAMI targets were selected from a number of pseudo volume-limited samples, with each volume based on a spectroscopic redshift corrected for local flow effects (Tonry et al 2000) and galaxy stellar mass estimates of Taylor et al (2011).…”

Section: Target Selectionmentioning

confidence: 99%

The SAMI Galaxy Survey: spatially resolving the environmental quenching of star formation in GAMA galaxies

Schaefer

Croom

Allen

et al. 2016

Self Cite

We use data from the Sydney-AAO Multi-Object Integral Field Spectrograph (SAMI) Galaxy Survey and the Galaxy And Mass Assembly (GAMA) survey to investigate the spatially-resolved signatures of the environmental quenching of star formation in galaxies. Using dust-corrected measurements of the distribution of Hα emission we measure the radial profiles of star formation in a sample of 201 star-forming galaxies covering three orders of magnitude in stellar mass (M * ; 10 8.1 -10 10.95 M ) and in 5 th nearest neighbour local environment density (Σ 5 ; 10 −1.3 -10 2.1 Mpc −2 ). We show that star formation rate gradients in galaxies are steeper in dense (log 10 (Σ 5 /Mpc 2 ) > 0.5) environments by 0.58 ± 0.29 dex r e −1 in galaxies with stellar masses in the range 10 10 < M * /M < 10 11 and that this steepening is accompanied by a reduction in the integrated star formation rate. However, for any given stellar mass or environment density the star-formation morphology of galaxies shows large scatter. We also measure the degree to which the star formation is centrally concentrated using the unitless scaleradius ratio (r 50,Hα /r 50,cont ), which compares the extent of ongoing star formation to previous star formation. With this metric we find that the fraction of galaxies with centrally concentrated star formation increases with environment density, from ∼ 5 ± 4% in low-density environments (log 10 (Σ 5 /Mpc 2 ) < 0.0) to 30 ± 15% in the highest density environments (log 10 (Σ 5 /Mpc 2 ) > 1.0). These lines of evidence strongly suggest that with increasing local environment density the star formation in galaxies is suppressed, and that this starts in their outskirts such that quenching occurs in an outside-in fashion in dense environments and is not instantaneous.

“…GAMA is 98 per cent spectroscopically complete down to m r = 19.8 even in the most crowded regions (Baldry et al 2010;Driver et al 2011;Liske et al 2015). Here, we use data over three different regions on the sky, centred at right ascensions 9 h , 12 h and 15 h (the G09, G12 and G15 fields), which overlap with SDSS data.…”

mentioning

confidence: 99%

The masses of satellites in GAMA galaxy groups from 100 square degrees of KiDS weak lensing data

Sifón¹,

Cacciato²,

Hoekstra³

et al. 2015

We use the first 100 deg 2 of overlap between the Kilo-Degree Survey (KiDS) and the Galaxy And Mass Assembly (GAMA) survey to determine the galaxy halo mass of ∼10,000 spectroscopically-confirmed satellite galaxies in massive (M > 10 13 h −1 M ) galaxy groups. Separating the sample as a function of projected distance to the group centre, we jointly model the satellites and their host groups with Navarro-Frenk-White (NFW) density profiles, fully accounting for the data covariance. The probed satellite galaxies in these groups have total masses log M sub /(h −1 M ) ≈ 11.7 − 12.2 consistent across group-centric distance within the errorbars. Given their typical stellar masses, log M ,sat /(h −2 M ) ∼ 10.5, such total masses imply stellar mass fractions of M ,sat /M sub ≈ 0.04 h −1 . The average subhalo hosting these satellite galaxies has a mass M sub ∼ 0.015M host independent of host halo mass, in broad agreement with the expectations of structure formation in a ΛCDM universe.