Kyle Willett edited subsubsection_GZ_multi_wavelength_morphologies__.tex  over 8 years ago

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The Galaxy Zoo project uses crowdsourced visual classifications to generate robust catalogs of detailed galaxy morphology. We present results from a study of how kpc-scale galaxy morphology changes as a function of observed wavelength. This includes classifications of color-composite $gri$ images from the SDSS, as well as individual single-band images of each of the $ugriz$ bands for a sample of 1000 disk galaxies. We supplement these with near-infrared color-composite images from UKIDSS in the $YHK$ bands. The range in observed wavelength isolates the effect of different stellar populations, discrete UV-bright star forming regions, and dust clouds on morphology. We show that the fraction of galactic bars detected peaks in the $i$-band for optical galaxies, although the overall bar fraction is relatively flat for all bands in $griz$ between 41\% and 56\%. Optical $u$-band images show a much higher rate of disks where the bar is undetected, at only 13\%. We show that there is a mild (?) correlation between bar fraction and bar length in optical bands, both as a function of absolute size and as a fraction of the total disk diameter. In near-infrared wavelengths, bars are detected at slightly lower fractions than in optical; the data show that this is frequently driven by misclassification of barred face-on disks as edge-on disks, where the lack of contrast between the bar and the outer edge of the disk in the near-infrared drives the confusion. Overall, the detection of bars in disks is shown not to be a strong function of wavelength over the majority of the stellar blackbody emission between $400-2000$~nm.  \subsubsection*{Galaxy Zoo Hubble: First results of the redshift evolution of disk fraction in the red sequence}  \textit{\textbf{M.A. Galloway et al.}}  [in progress: Sentences of what we already know and why we care]  [this is so vague oh my goodness]  Using images from the Hubble Space Telescope (HST) and morphological classifications from the Galaxy Zoo: Hubble project, we constructed a large sample of disk galaxies spanning   a wide ($0 < z < 1.0$) redshift range. We use this sample to examine the change in the fraction of disks in the red sequence with respect to all disks from the local to early Universe. This result points to possible scenarios of galactic evolution which would explain the observed relation between disk fraction and cosmic time.   \subsubsection*{Melanie's Abstract}