Uncovering galaxy individuality with multiplexed integral field spectroscopy.

Scott Croom,Julia Bryant 한국천문학회 2017 天文學會報 Vol.42 No.1

The SAMI Galaxy Survey: global stellar populations on the size–mass plane

Scott, Nicholas,Brough, S.,Croom, Scott M.,Davies, Roger L.,van de Sande, Jesse,Allen, J. T.,Bland-Hawthorn, Joss,Bryant, Julia J.,Cortese, Luca,D'Eugenio, Francesco,Federrath, Christoph,Ferreras, Ign Oxford University Press 2017 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.472 No.3

Effect of Genotype on Whole-body and Intestinal Metabolic Response to Monensin in Mice

Fan, Y.K.,Croom, W.J.,Daniel, Linda,McBride, B.W.,Koci, M.,Havenstein, G.B.,Eisen, E.J. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.4

Two lines of mice, M16 selected for rapid growth and a randomly selected control ICR as well as their reciprocal crosses were used to study the effects of genotype on whole-body energetics and intestinal responses to monensin. Six mice, eight weeks of age, from each line or reciprocal cross were assigned to one of two treatments, 1) drinking water containing 20 mmol/L monensin dissolved in 0.5% V/V ethanol, and 2) drinking water containing 0.5% V/V ethanol (control) for two weeks. After 11 days (age of 9 weeks and 4 days), whole-body $O_2$ consumption was measured. At the end of two weeks, jejunal $O_2$ consumption, intestinal tissue composition and histomorphometrics as well as the rate and efficiency of glucose absorption were estimated. In comparison with the control, monensin administration in drinking water resulted in less daily water intake (13.4 vs. 15.5 ml/mouse, p<0.01), less protein to DNA ratio of jejunal mucosa (5.41 vs. 6.01 mg/mg, p<0.05), lower villus width (88 vs. $100{\mu}m$, p<0.05), and less jejunal tissue $O_2$ consumption enhancement by alcohol (7.2 vs. 10.5%, p<0.01) in mice. Other than those changes, monensin had little (p>0.05) effect on variables measured in either line of mice or their reciprocal cross. In contrast, the M16 line, selected for rapid growth, as compared to the ICR controls or the reciprocal crosses, had less initial (pre-monensin treatment) whole-body $O_2$ consumption per gram of body weight (1.68 vs. $2.11-2.34{\mu}mol/min{\cdot}g$ BW, p<0.01) as compared to the ICR and reciprocal crosses. In addition, the M16 mice exhibited greater growth (412 vs. 137-210 mg/d, p<0.05), better feed efficiency (41.7 vs. 19.9-29.3 mg gain/g feed, p<0.05), shorter small intestines adjusted for fasted body weight (1.00 vs. 1.22-1.44 cm/g FBW, p<0.05), wider villi (109 vs. $87-93{\mu}m$, p<0.05), more mature height of enterocytes (28.8 vs. $24.4-25.1{\mu}m$, p<0.05) and a lower rate (91 vs. $133-145{\eta}mol\;glucose/min{\cdot}g$ jejunum, p<0.05) and less energetic efficiency (95 vs. $59-72{\eta}mol$ ATP expended/${\eta}mol$ glucose uptake, p<0.05) of glucose absorption compared to the ICR line and the reciprocal cross. Monensin had little (p>0.05) effect on whole-body $O_2$ consumption and jejunal function, whilst selection for rapid growth resulted in an apparent down-regulation of intestinal function. These data suggest that genetic selection for increased growth does not result in concomitant changes in intestinal function. This asynchrony in the selection for production traits and intestinal function may hinder full phenotypic expression of genotypic growth potential.

Development of a Dynamic System Simulating Pig Gastric Digestion

Chiang, C.-C.,Croom, J.,Chuang, S.-T.,Chiou, P.W.S.,Yu, B. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.10

The objective of this study was to develop a model for simulating gastric digestion in the pig. The model was constructed to include the chemical and physical changes associated with gastric digestion such as enzyme release, digestion product removal and gastric emptying. Digesta was collected from the stomach cannula of pigs to establish system parameters and to document the ability of the model to simulate gastric digestion. The results showed that the average pH of gastric digesta increased significantly from 2.47 to 4.97 after feed consumption and then decreased 140 min postprandial. The model described the decrease in pH within the pigs' stomach as $pH_t=5.182e^{-0.0014t}$, where t represents the postprandial time in minutes. The cumulative distribution function of liquid digesta was $V_t=64.509e^{0.0109t}$. The average pepsin activity in the liquid digesta was 317Anson units/mL. There was significant gastric emptying 220 min after feed consumption. The cybernetic dynamic system of gastric digestion was set according to the above data in order to compare with in vivo changes. The time course of crude protein digestion predicted by the model was highly correlated with observed in vivo digestion (r = 0.97; p = 0.0001), Model prediction for protein digestion was higher than that observed for a traditional static in vitro method (r = 0.89; p = 0.0001).

The SAMI Galaxy Survey: observing the environmental quenching of star formation in GAMA groups

Schaefer, A L,Croom, S M,Scott, N,Brough, S,Allen, J T,Bekki, K,Bland-Hawthorn, J,Bloom, J V,Bryant, J J,Cortese, L,Davies, L J M,Federrath, C,Fogarty, L M R,Green, A W,Groves, B,Hopkins, A M,Konstant Oxford University Press 2019 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.483 No.3

The SAMI Galaxy Survey: revising the fraction of slow rotators in IFS galaxy surveys

van de Sande, Jesse,Bland-Hawthorn, Joss,Brough, Sarah,Croom, Scott M.,Cortese, Luca,Foster, Caroline,Scott, Nicholas,Bryant, Julia J.,d'Eugenio, Francesco,Tonini, Chiara,Goodwin, Michael,Konstantopou Oxford University Press 2017 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.472 No.2

<P>The fraction of galaxies supported by internal rotation compared to galaxies stabilized by internal pressure provides a strong constraint on galaxy formation models. In integral field spectroscopy surveys, this fraction is biased because survey instruments typically only trace the inner parts of the most massive galaxies. We present aperture corrections for the two most widely used stellar kinematic quantities V/sigma and lambda(R) (spin parameter proxy). Our demonstration involves integral field data from the SAMI (Sydney-AAO Multi-object Integral-field spectrograph) Galaxy Survey and the ATLAS(3D) survey. We find a tight relation for both V/sigma and lambda(R) when measured in different apertures that can be used as a linear transformation as a function of radius, i.e. a first-order aperture correction. In degraded seeing, however, the aperture corrections are more significant as the steeper inner profile is more strongly affected by the point spread function than the outskirts. We find that V/sigma and lambda(R) radial growth curves are well approximated by second-order polynomials. By only fitting the inner profile (0.5R(e)), we successfully recover the profile out to one R-e if a constraint between the linear and quadratic parameter in the fit is applied. However, the aperture corrections for V/sigma and lambda(R) derived by extrapolating the profiles perform as well as applying a first-order correction. With our aperture-corrected lambda(R) measurements, we find that the fraction of slow rotating galaxies increases with stellar mass. For galaxies with log M-*/M-circle dot > 11, the fraction of slow rotators is 35.9 +/- 4.3 per cent, but is underestimated if galaxies without coverage beyond one R-e are not included in the sample (24.2 +/- 5.3 per cent). With measurements out to the largest aperture radius, the slow rotator fraction is similar as compared to using aperture-corrected values (38.3 +/- 4.4 per cent). Thus, aperture effects can significantly bias stellar kinematic integral field spectrograph studies, but this bias can now be removed with the method outlined here.</P>

Merger Induced Kinematic Anomalies in Abell 119

Sree Oh,Hyunjin Jeong,Yun-Kyeong Sheen,Scott Croom,Sukyoung Yi 한국천문학회 2016 天文學會報 Vol.41 No.1

Feeding Value of High-oil Corn for Taiwan Country Chicken

Lin, Min-Jung,Chiou, Peter Wen-Shyg,Chang, Shen-Chang,Croom, Jim,Fan, Yang-Kwang Asian Australasian Association of Animal Productio 2003 Animal Bioscience Vol.16 No.9

The feeding value of high-oil corn fed to Taiwan Country (TC) chicken was examined by measuring apparent metabolizable energy (AME), growth performance, sexual maturity, carcass characteristics, and plasma pigmentation. In a completely randomized design, 870 sex-intermingled one-wk-old chicks were assigned to one of 30 floor pens, 29 birds per pen, and each pen randomly assigned to one of five dietary treatments. The experiment was ended when birds were 16 wk of age. The five dietary treatments varied in main fat sources, which were corn oil (CO), high-oil corn (HOC), lard (LRD), whole soybean (WSB) and yellow corn (YC), respectively. All the diets were formulated isonitrogenously, isocalorically, and of equal lysine and methionine contents except YC, in which equal amounts of YC replaced HOC. The results indicated that feed conversion in HOC was 8% higher (p<0.05) than YC whereas the calculated AME of HOC was only 3.5% to 4.0% higher than that of YC. No significant differences were observed in body weight, body weight gain, feed consumption, feed conversion ratio and ME efficiency for body weight gain among CO, HOC, LRD, and WSB. No significant differences existed in both skin and muscle pigmentation of breast among the five dietary treatments. No significance differences existed in plasma carotenoid content measured at various ages among the five dietary treatments except that birds fed with HOC had less (p<0.05) plasma carotenoids at 16 wk-old. The results indicate that if the price of high-oil corn is no more than 1.05 times that of yellow corn, the dietary cost per kg of body weight gain for TC chickens fed diets containing high-oil corn will be less, although their body weight may be lighter compared to chickens fed diets formulated with other fat sources.

The SAMI Galaxy Survey: Mass as the Driver of the Kinematic Morphology-Density Relation in Clusters

Brough, Sarah,van de Sande, Jesse,Owers, Matt S.,d’Eugenio, Francesco,Sharp, Rob,Cortese, Luca,Scott, Nicholas,Croom, Scott M.,Bassett, Rob,Bekki, Kenji,Bland-Hawthorn, Joss,Bryant, Julia J.,Davies, R American Astronomical Society 2017 The Astrophysical journal Vol.844 No.1

<P>We examine the kinematic morphology of early-type galaxies (ETGs) in eight galaxy clusters in the Sydney-AAO Multi-object Integral-field spectrograph Galaxy Survey. The clusters cover a mass range of 14.2 < log(M-200/M-circle dot) < 15.2 and we measure spatially resolved stellar kinematics for 315 member galaxies with stellar masses 10.0 < log(M-*/M-circle dot) <= 11.7 within 1 R-200 of the cluster centers. We calculate the spin parameter, lambda(R), and use this to classify the kinematic morphology of the galaxies as fast or slow rotators (SRs). The total fraction of SRs in the ETG population is F-SR = 0.14 +/- 0.02 and does not depend on host cluster mass. Across the eight clusters, the fraction of SRs increases with increasing local overdensity. We also find that the slow-rotator fraction increases at small clustercentric radii (R-cl < 0.3 R-200), and note that there is also an increase in the slow-rotator fraction at R-cl similar to 0.6 R-200. The SRs at these larger radii reside in the cluster substructure. We find that the strongest increase in the slow-rotator fraction occurs with increasing stellar mass. After accounting for the strong correlation with stellar mass, we find no significant relationship between spin parameter and local overdensity in the cluster environment. We conclude that the primary driver for the kinematic morphology-density relationship in galaxy clusters is the changing distribution of galaxy stellar mass with the local environment. The presence of SRs in the substructure suggests that the cluster kinematic morphology-density relationship is a result of mass segregation of slow-rotating galaxies forming in groups that later merge with clusters and sink to the cluster center via dynamical friction.</P>

THE SAMI GALAXY SURVEY: REVISITING GALAXY CLASSIFICATION THROUGH HIGH-ORDER STELLAR KINEMATICS

Sande, Jesse van de,Bland-Hawthorn, Joss,Fogarty, Lisa M. R.,Cortese, Luca,d’Eugenio, Francesco,Croom, Scott M.,Scott, Nicholas,Allen, James T.,Brough, Sarah,Bryant, Julia J.,Cecil, Gerald,Colless, Ma American Astronomical Society 2017 The Astrophysical journal Vol.835 No.1

<P>Recent cosmological hydrodynamical simulations suggest that integral field spectroscopy can connect the high-order stellar kinematic moments h(3) (similar to skewness) and h(4) (similar to kurtosis) in galaxies to their cosmological assembly history. Here, we assess these results by measuring the stellar kinematics on a sample of 315 galaxies, without a morphological selection, using two-dimensional integral field data from the SAMI Galaxy Survey. Proxies for the spin parameter (lambda(Re)) and ellipticity (epsilon(e)) are used to separate fast and slow rotators; there exists a good correspondence to regular and non-regular rotators, respectively, as also seen in earlier studies. We confirm that regular rotators show a strong h(3) versus V/sigma s anti-correlation, whereas quasi-regular and non-regular rotators show a more vertical relation in h(3) and V/sigma. Motivated by recent cosmological simulations, we develop an alternative approach to kinematically classify galaxies from their individual h(3) versus V/sigma signatures. Within the SAMI Galaxy Survey, we identify five classes of high-order stellar kinematic signatures using Gaussian mixture models. Class 1 corresponds to slow rotators, whereas Classes 2-5 correspond to fast rotators. We find that galaxies with similar lambda(Re)-epsilon(e) -values can show distinctly different h(3)-V/sigma signatures. Class 5 objects are previously unidentified fast rotators that show a weak h(3) versus V/sigma anti-correlation. From simulations, these objects are predicted to be disk-less galaxies formed by gas-poor mergers. From morphological examination, however, there is evidence for large stellar disks. Instead, Class 5 objects are more likely disturbed galaxies, have counter-rotating bulges, or bars in edge-on galaxies. Finally, we interpret the strong anti-correlation in h(3) versus V/sigma as evidence for disks in most fast rotators, suggesting a dearth of gas-poor mergers among fast rotators.</P>