TY - JOUR

T1 - Galaxy Zoo

T2 - quantitative visual morphological classifications for 48 000 galaxies from CANDELS

AU - Simmons, B. D.

AU - Lintott, Chris

AU - Willett, Kyle W.

AU - Masters, Karen L.

AU - Kartaltepe, Jeyhan S.

AU - Häußler, Boris

AU - Kaviraj, Sugata

AU - Krawczyk, Coleman

AU - Kruk, S. J.

AU - Mcintosh, Daniel H.

AU - Smethurst, R. J.

AU - Nichol, Robert C.

AU - Scarlata, Claudia

AU - Schawinski, Kevin

AU - Conselice, Christopher J.

AU - Almaini, Omar

AU - Ferguson, Henry C.

AU - Fortson, Lucy

AU - Hartley, William

AU - Kocevski, Dale

AU - Koekemoer, Anton M.

AU - Mortlock, Alice

AU - Newman, Jeffrey A.

AU - Bamford, Steven P.

AU - Grogin, N. A.

AU - Lucas, Ray A.

AU - Hathi, Nimish P.

AU - Mcgrath, Elizabeth

AU - Peth, Michael

AU - Pforr, Janine

AU - Rizer, Zachary

AU - Wuyts, Stijn

AU - Barro, Guillermo

AU - Bell, Eric F.

AU - Castellano, Marco

AU - Dahlen, Tomas

AU - Dekel, Avishai

AU - Ownsworth, Jamie

AU - Faber, Sandra M.

AU - Finkelstein, Steven L.

AU - Fontana, Adriano

AU - Galametz, Audrey

AU - Grützbauch, Ruth

AU - Koo, David

AU - Lotz, Jennifer

AU - Mobasher, Bahram

AU - Mozena, Mark

AU - Salvato, Mara

AU - Wiklind, Tommy

PY - 2017/2/1

Y1 - 2017/2/1

N2 - We present quantified visual morphologies of approximately 48 000 galaxies observed in three Hubble Space Telescope legacy fields by the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) and classified by participants in the Galaxy Zoo project. 90 per cent of galaxies have z ≤ 3 and are observed in rest-frame optical wavelengths by CANDELS. Each galaxy received an average of 40 independent classifications, which we combine into detailed morphological information on galaxy features such as clumpiness, bar instabilities, spiral structure, and merger and tidal signatures. We apply a consensus-based classifier weighting method that preserves classifier independence while effectively down-weighting significantly outlying classifications. After analysing the effect of varying image depth on reported classifications, we also provide depth-corrected classifications which both preserve the information in the deepest observations and also enable the use of classifications at comparable depths across the full survey. Comparing the Galaxy Zoo classifications to previous classifications of the same galaxies shows very good agreement; for some applications, the high number of independent classifications provided by Galaxy Zoo provides an advantage in selecting galaxies with a particular morphological profile, while in others the combination of Galaxy Zoo with other classifications is a more promising approach than using any one method alone. We combine the Galaxy Zoo classifications of ‘smooth’ galaxies with parametric morphologies to select a sample of featureless discs at 1 ≤ z ≤ 3, which may represent a dynamically warmer progenitor population to the settled disc galaxies seen at later epochs.

AB - We present quantified visual morphologies of approximately 48 000 galaxies observed in three Hubble Space Telescope legacy fields by the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) and classified by participants in the Galaxy Zoo project. 90 per cent of galaxies have z ≤ 3 and are observed in rest-frame optical wavelengths by CANDELS. Each galaxy received an average of 40 independent classifications, which we combine into detailed morphological information on galaxy features such as clumpiness, bar instabilities, spiral structure, and merger and tidal signatures. We apply a consensus-based classifier weighting method that preserves classifier independence while effectively down-weighting significantly outlying classifications. After analysing the effect of varying image depth on reported classifications, we also provide depth-corrected classifications which both preserve the information in the deepest observations and also enable the use of classifications at comparable depths across the full survey. Comparing the Galaxy Zoo classifications to previous classifications of the same galaxies shows very good agreement; for some applications, the high number of independent classifications provided by Galaxy Zoo provides an advantage in selecting galaxies with a particular morphological profile, while in others the combination of Galaxy Zoo with other classifications is a more promising approach than using any one method alone. We combine the Galaxy Zoo classifications of ‘smooth’ galaxies with parametric morphologies to select a sample of featureless discs at 1 ≤ z ≤ 3, which may represent a dynamically warmer progenitor population to the settled disc galaxies seen at later epochs.

U2 - 10.1093/mnras/stw2587

DO - 10.1093/mnras/stw2587

M3 - Journal article

VL - 464

SP - 4420

EP - 4447

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 4

ER -