Automated detection of merging galaxies at z = 0.25 − 1.0 in the CLAUDS+HSC survey using random forests

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dc.contributor.advisor Sawicki, Marcin, 1969-
dc.creator Thibert, Nathalie C. M.
dc.date.accessioned 2018-09-19T14:13:14Z
dc.date.available 2018-09-19T14:13:14Z
dc.date.issued 2018
dc.identifier.other QB857.5 M47 T48 2018
dc.identifier.uri http://library2.smu.ca/handle/01/27980
dc.description x, 190 leaves : colour illustrations ; 29 cm
dc.description Includes abstract and appendix.
dc.description Includes bibliographical references (leaves 135-142).
dc.description.abstract Using a sample of galaxies (M⋆ &ge; 10<sup>10.5</sup>M<sub>⊙</sub>) covering an effective area of &sim; 20 deg<sup>2</sup> in the CLAUDS+HSC survey, we apply a Random Forest Classifier to automatically identify merger candidates in deep r-band images. We identify a largely pure, &sim; 90% complete sample of mergers which we use to derive the evolution in the merger fraction from 0.25 &le; z<sub>phot</sub> &le; 1.0. We parameterize the merger fraction evolution with a power law of the form f<sub>m</sub> = f<sub>0</sub>(1+z)<sup>m</sup> . Simulating the effects of increasing redshift on the detectability of mergers, we correct our merger fractions for incompleteness to obtain a local merger fraction of f<sub>0</sub> = 1.0%&plusmn;0.2% and power-law index of m = 2.3&plusmn;0.4, which is inconsistent with the mild or non-evolving merger scenario (m &lt; 1.5) with 96.6% confidence. Finally, we estimate 0.3 merging events to occur per massive galaxy since z = 1. en_CA
dc.language.iso en en_CA
dc.publisher Halifax, N.S. : Saint Mary's University
dc.subject.lcc QB857.5.M47
dc.subject.lcsh Galaxy mergers
dc.subject.lcsh Galaxies -- Evolution
dc.title Automated detection of merging galaxies at z = 0.25 − 1.0 in the CLAUDS+HSC survey using random forests en_CA
dc.type Text en_CA
thesis.degree.name Master of Science in Astronomy
thesis.degree.level Masters
thesis.degree.discipline Astronomy and Physics
thesis.degree.grantor Saint Mary's University (Halifax, N.S.)


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