J/ApJ/835/104 SAMI Galaxy Survey: rotators classification (van de Sande+, 2017)
The SAMI Galaxy Survey: revisiting Galaxy classification through high-order stellar kinematics. van de Sande J., Bland-Hawthorn J., Fogarty L.M.R., Cortese L., D'Eugenio F., Croom S.M., Scott N., Allen J.T., Brough S., Bryant J.J., Cecil G., Colless M., Couch W.J., Davies R., Elahi P.J., Foster C., Goldstein G., Goodwin M., Groves B., Ho I.-T., Jeong H., Jones D.H., Konstantopoulos I.S., Lawrence J.S., Leslie S.K., Lopez-Sanchez A.R., McDermid R.M., McElroy R., Medling A.M., Oh S., Owers M.S., Richards S.N., Schaefer A.L., Sharp R., Sweet S.M., Taranu D., Tonini C., Walcher C.J., Yi S.K. <Astrophys. J., 835, 104-104 (2017)> =2017ApJ...835..104V (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra ; Surveys ; Redshifts ; Morphology Keywords: cosmology: observations; galaxies: evolution; galaxies: formation; galaxies: kinematics and dynamics; galaxies: stellar content; galaxies: structure Abstract: Recent cosmological hydrodynamical simulations suggest that integral field spectroscopy can connect the high-order stellar kinematic moments h3 (∼skewness) and h4 (∼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 (λRe) and ellipticity (εe) 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 h3 versus V/σ anti-correlation, whereas quasi-regular and non-regular rotators show a more vertical relation in h3 and V/σ. Motivated by recent cosmological simulations, we develop an alternative approach to kinematically classify galaxies from their individual h3 versus V/σ 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 λRe-εe values can show distinctly different h3-V/σ signatures. Class 5 objects are previously unidentified fast rotators that show a weak h3 versus V/σ 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 h3 versus V/σ as evidence for disks in most fast rotators, suggesting a dearth of gas-poor mergers among fast rotators. Description: The SAMI instrument and Galaxy Survey is described in detail in Croom+ (2012MNRAS.421..872C) and Bryant+ (2015MNRAS.447.2857B). SAMI is a multi-object integral field spectrograph on the 3.9m Anglo Australian Telescope (AAT). For the SAMI Galaxy Survey, the 580V grating is used in the blue arm of the spectrograph, which results in a resolution of R∼1700 with wavelength coverage of 3700-5700Å. In the red arm, the higher resolution grating 1000R is used, which gives an R∼4500 over the range 6300-7400Å. We use 24 unsaturated, unblended CuAr arc lines in the blue arm, and 12 lines in the red arm, from 16 frames between 2013 March 05 and 2015 August 17, for all 819 fibers. The survey has four volume-limited galaxy samples derived from cuts in stellar mass in the Galaxy and Mass Assembly (GAMA) G09, G12, and G15 regions (Driver+ 2011, J/MNRAS/413/971). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 85 315 Compilation of all measured quantities table3.dat 36 315 Log-likehood estimates and high-order classification
See also: J/MNRAS/371/703 : MILES library of empirical spectra (Sanchez-Blazquez+, 2006) J/MNRAS/404/1639 : MILES base models & new line index system (Vazdekis+, 2010) J/MNRAS/413/813 : ATLAS3D project. I. (Cappellari+, 2011) J/MNRAS/416/1680 : ATLAS3D project. VII. (Cappellari+, 2011) J/MNRAS/413/971 : Galaxy And Mass Assembly (GAMA) DR1 (Driver+, 2011) J/MNRAS/414/888 : ATLAS3D project. III. (Emsellem+, 2011) J/A+A/556/A55 : Multi-color photom. of star-forming galaxies (Ilbert+, 2013) J/ApJ/777/18 : Stellar mass functions of galaxies to z=4 (Muzzin+, 2013) J/ApJ/771/85 : Dynamical masses of z∼2 quiescent gal. (van de Sande+, 2013) J/MNRAS/446/1567 : SAMI Galaxy Survey: Early Data Release (Allen+, 2015) J/MNRAS/454/2050 : SAMI Pilot Survey (Fogarty+, 2015) J/MNRAS/452/2087 : Galaxy And Mass Assembly (GAMA): DR2 (Liske+, 2015) J/A+A/591/A143 : NGC 3115 MUSE images (Guerou+, 2016) J/MNRAS/456/1299 : SAMI Galaxy Survey: gas streaming (Cecil+, 2016) http://sami-survey.org/ : SAMI Galaxy Survey website http://www.gama-survey.org/ : Galaxy And Mass Assembly (GAMA) home page Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 10 I10 --- ID [8487/9403801368] Catalog ID (CATID) (G1) 12- 17 F6.4 --- zsp [0.01/0.09] Spectroscopic redshift 19- 23 F5.2 [Msun] logM* [10/11.6] Log stellar mass 25- 28 F4.2 mag g-i [0.7/1.4] g-i color index 30- 35 F6.3 kpc Re [0.8/15.8] Effective semi-major axis 37- 41 F5.3 --- ell Ellipticity 43- 47 F5.3 --- rmaxSig [0.3/3.6] Maximum aperture radius velocity dispersion, normalised by Re 49- 53 F5.3 --- rmaxh3 [0.1/1.5] Maximum aperture radius h3, normalised by Re 55- 61 F7.3 --- lamRe [0.03/0.7]?=-99 Spin parameter proxy within one Re 63- 67 F5.3 --- e_lamRe [0.002/0.02]?=0 Error on lamRe 69- 76 F8.4 --- <k5k1Re> [0.007/2]?=-99 Mean kinemetry k5/k1 value within one Re 78- 85 F8.4 --- e_<k5k1Re> [0.002/612]?=0 Error on <k5k1Re>
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 10 I10 --- ID [8487/9403801368] Catalog ID (CATID) (G1) 12- 15 F4.2 --- Sigamaj [0.03/1] Best-fit standard deviation along major axis of high-order data (σmajor) 17- 21 F5.3 --- Sigmbmin [0.02/0.07] Best-fit standard deviation along minor axis of high-order data (σminor) 23- 28 F6.2 --- phi [-45/5] Best-fit angle Φ of high-order data 30- 34 F5.2 --- Corr [-1/0.4] Pearson correlation coefficient of high-order data 36 I1 --- Cl [1/5] High-order stellar kinematic class (1)
Note (1): Class as follows: 1 = galaxies mostly found on the red sequence and dominate at the high-mass end (M*>1011M☉); the range of V/σ is very narrow as compared to the range of h4, with no trend, similar to the h3 signatures (slow rotators; 52 occurrences). 2 = galaxies with a lower mean stellar masses than Class 1, but the bulk resides on the red sequence; broader spread in V/σ as compared to Class 1 (97 occurrences). 3 = heart-shape clear for regular rotator (64 occurrences) 4 = heart-shape clear for regular rotator (57 occurrences) 5 = galaxies which have a large range in both color and stellar mass; rounder distribution in h4 and V/σ (45 occurrences). See text for further explanations.
Global Notes: Note (G1): The galaxies with ID≥9008500007 are from a catalog produced by Dr Matt Owers. General Information on these targets are available in Owers et al. 2017, but unfortunately the catalogs from those papers are not publicly available yet. They will be made available as part of an upcoming SAMI Data Release.
History: From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 11-Aug-2017
|The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line|