BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//ZContent.net//ZapCalLib 1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
DTSTART;TZID=Atlantic/Canary:20140925T103000
DTEND;TZID=Atlantic/Canary:20140925T113000
UID:iactalks-656
X-WR-CALNAME: IAC Talks: Open Astronomy Seminars
X-ORIGINAL-URL: /iactalks/Talks/view/656
CREATED:2014-09-25T10:30:00+01:00
X-WR-CALDESC: IAC Talks upcomming talks
SUMMARY:GALAPAGOS in C - computational study of galaxy morphologies
DESCRIPTION:GALAPAGOS in C - computational study of galaxy morphologies\nMr
 . Andreas Hiemer\n\nModern imaging surveys provide a fundamental tool in o
 rder to study the morphologicalproperties of galaxy populations in the nea
 rby and the distant Universe. In order toprocess a complete set of survey 
 images, we designed GALAPAGOS-C. GALAPAGOS-Cunifies the detection of sourc
 es (via source extractor), postage stamp cutting, objectmask preparation, 
 sky background estimation and complex two-dimensional light profileS&eacut
 e;rsic modeling (via GALFIT) in one automatic program. GALAPAGOS-C is desi
 gnedaround the concept of MPI-parallelization, allowing the processing of 
 large data setsin a quick and efficient manner. Further, GALAPAGOS-C is ca
 pable of fitting multiple-Sérsic profiles to each galaxy, each repr
 esenting distinct galaxy components (e.g. bulge,disc, bar), in addition to
  the option to fit asymmetric distortions with a Fourier modeexpansion to 
 the axis-symmetric single-Sérsic isophotes. The modeling reliabilit
 y of ourcore single-Sérsic fitting capability and the optional Four
 ier mode expansion are testedthoroughly using image simulations.GALAPAGOS-
 C is applied to a sample of 2063 galaxies in the A901/902 galaxy cluster(z
  ∼ 0.165) from the Space Telescope A901/902 Galaxy Evolution Survey (S
 TAGES) andan additional sample of 2876 field galaxies from the Galaxy Evol
 ution From MorphologyAnd SEDs Survey (GEMS). We measure the distribution o
 f Sérsic indices as a function oflocal object density in the A901/9
 02 cluster sample to provide one of the first measuresof the Sérsic
  index–density relation. In addition, we measure the distribution of
  lopsidedgalaxies in the A901/902 cluster sample and quantify the intensit
 y of lopsidedness inthe galaxies in the field since z ∼ 0.9 in order t
 o study the evolution of lopsidedness asa function of redshift. In each ap
 plication, we study the correlations of the measuredparameters with other 
 intrinsic and structural variables, e.g. the stellar mass, the coloror the
  presence or absence of a disk. Our results provide further clues on the e
 volutionof galaxy structure with cosmic time and the dependence on environ
 ment.
END:VEVENT
END:VCALENDAR