The SAMI Galaxy Survey : spatially resolving the main sequence of star formation

We present the ∼800 star formation rate maps for the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey based on H α emission maps, corrected for dust attenuation via the Balmer decrement, that are included in the SAMI Public Data Release 1. We mask out spaxels contaminated by non-stellar emission using the [O iii]/H β, [N ii]/H α, [S ii]/H α, and [O i]/H α line ratios. Using these maps, we examine the global and resolved star-forming main sequences of SAMI galaxies as a function of morphology, environmental density, and stellar mass. Galaxies further below the star-forming main sequence are more likely to have flatter star formation profiles. Early-type galaxies split into two populations with similar stellar masses and central stellar mass surface densities. The main-sequence population has centrally concentrated star formation similar to late-type galaxies, while galaxies >3σ below the main sequence show significantly reduced star formation most strikingly in the nuclear regions. The split populations support a two-step quenching mechanism, wherein halo mass first cuts off the gas supply and remaining gas continues to form stars until the local stellar mass surface density can stabilize the reduced remaining fuel against further star formation. Across all morphologies, galaxies in denser environments show a decreased specific star formation rate from the outside in, supporting an environmental cause for quenching, such as ram-pressure stripping or galaxy interactions.Publisher PDFPeer reviewe

The SAMI Galaxy Survey: spatially resolving the main sequence of star formation

We present the ~800 star formation rate maps for the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey based on Ha emission maps, corrected for dust attenuation via the Balmer decrement, that are included in the SAMI Public Data Release 1. We mask out spaxels contaminated by non-stellar emission using the [O III]/H β, [NII]/H α, [S II]/H α, and [O I]/H α line ratios. Using thesemaps, we examine the global and resolved starforming main sequences of SAMI galaxies as a function of morphology, environmental density, and stellar mass. Galaxies further below the star-forming main sequence are more likely to have flatter star formation profiles. Early-type galaxies split into two populations with similar stellar masses and central stellar mass surface densities. The main-sequence population has centrally concentrated star formation similar to late-type galaxies, while galaxies > 3σ below the main sequence show significantly reduced star formation most strikingly in the nuclear regions. The split populations support a two-step quenching mechanism, wherein halo mass first cuts off the gas supply and remaining gas continues to form stars until the local stellar mass surface density can stabilize the reduced remaining fuel against further star formation. Across all morphologies, galaxies in denser environments show a decreased specific star formation rate from the outside in, supporting an environmental cause for quenching, such as ram-pressure stripping or galaxy interactions

The SAMI Galaxy Survey : data release one with emission-line physics value-added products

SAMI DR1 data products available from http://datacentral.aao.gov.au/asvo/surveys/sami/We present the first major release of data from the SAMI Galaxy Survey. This data release focuses on the emission-line physics of galaxies. Data Release One includes data for 772 galaxies, about 20% of the full survey. Galaxies included have the redshift range 0.004 <  z < 0.092, a large massrange (7.6 < log M∗/M⊙ < 11.6), and star-formation rates of ∼10−4 to ∼101 M⊙yr−1. For each galaxy, we include two spectral cubes and a set of spatially resolved 2D maps: single- and multi-component emission-line fits (with dust extinction corrections for strong lines), local dust extinction and star-formation rate. Calibration of the fibre throughputs, fluxes and differential-atmospheric-refraction has been improved over the Early Data Release. The data have average spatial resolution of 2.16 arcsec (FWHM) over the 15 arcsec diameter field of view and spectral (kinematic) resolution R= 4263 (σ= 30 km s−1) around Hα. The relative flux calibration is better than 5% and absolute flux calibration better than ±0.22 mag, with the latter estimate limited by galaxy photometry. The data are presented online through the Australian Astronomical Observatory’s Data Central.Publisher PDFPeer reviewe

Validity of Estimating Body Fat of Females: Effect of Age and Fitness

The influence of age and fitness factors on the validity of prediction equations for estimating percent body fat (%BF) of females was investigated for 60 females, ages 12 to 78 years. Regression equations specific to age and fitness subgroups were derived from a series of skinfold, girth, and diameter measurements of these subjects. The combination of anthropometric variables in these equations providing the highest multiple correlation coefficient varied according to both the aerobic power and age of the subjects. The validity coefficients and standard errors of estimate from previously published equations also varied from group to group, demonstrating again that equations to estimate %BF from anthropometric measurements are specific to the population from which they were derived. As cross-validation of the equation for young adult females in this study demonstrated, prediction errors are of such magnitude that the use of such equations for research or clinical application is highly questionable

Anthropometric, Spirometric, and Physiologic Comparisons of Migrant Japanese

Anthropometric measurements, pulmonary function, and maximal oxygen uptake determinations were obtained on 45 healthy males. The subjects were assigned to three groups of 15 each, according to racial origin and generation in a particular environment. These groups were Issei (native Japanese), X age = 24.4 years; Sansei (third-generation Japanese-Ameri­cans), X age = 19.9 years; and Caucasian (white Americans), X age = 26.7 years. The stature of Issei and Sansei was smaller than that of Caucasians. There were no differences in calculated percentage of body weight due to fat or estimated caloric intakes. Sansei had larger chest and wrist widths and thigh circumferences than those of the Issei, and smaller than or equal to those of the Caucasians. These structural differences were linked with pulmonary function and maximal oxygen uptake differences between the three groups. Comparison of the obtained data with previous data indicated a maximal average size of the Japanese to be 169 cm, which is genetically controlled. Environmental factors appeared to affect both structural differences and pulmonary dimension differences. When structural differences were considered, the Caucasians were found to be more physically fit than the Sansei, who in turn were fitter than the Issei. These differences can be explained by activity patterns

Anthropometric, Spirometric, and Physiologic Comparisons of Migrant Japanese

Anthropometric measurements, pulmonary function, and maximal oxygen uptake determinations were obtained on 45 healthy males. The subjects were assigned to three groups of 15 each, according to racial origin and generation in a particular environment. These groups were Issei (native Japanese), X age = 24.4 years; Sansei (third-generation Japanese-Ameri­cans), X age = 19.9 years; and Caucasian (white Americans), X age = 26.7 years. The stature of Issei and Sansei was smaller than that of Caucasians. There were no differences in calculated percentage of body weight due to fat or estimated caloric intakes. Sansei had larger chest and wrist widths and thigh circumferences than those of the Issei, and smaller than or equal to those of the Caucasians. These structural differences were linked with pulmonary function and maximal oxygen uptake differences between the three groups. Comparison of the obtained data with previous data indicated a maximal average size of the Japanese to be 169 cm, which is genetically controlled. Environmental factors appeared to affect both structural differences and pulmonary dimension differences. When structural differences were considered, the Caucasians were found to be more physically fit than the Sansei, who in turn were fitter than the Issei. These differences can be explained by activity patterns