_version_ 1866912928345620480
author Pearson, James
Dickinson, Hugh
Serjeant, Stephen
Walmsley, Mike
Fortson, Lucy
Kruk, Sandor
Masters, Karen L.
Simmons, Brooke D.
Smethurst, R. J.
Lintott, Chris
Zalesky, Lukas
McPartland, Conor
Weaver, John R.
Toft, Sune
Sanders, Dave
Chartab, Nima
McCracken, Henry Joy
Mobasher, Bahram
Szapudi, Istvan
East, Noah
Turner, Wynne
Malkan, Matthew
Pearson, William J.
Goto, Tomotsugu
Oi, Nagisa
author_facet Pearson, James
Dickinson, Hugh
Serjeant, Stephen
Walmsley, Mike
Fortson, Lucy
Kruk, Sandor
Masters, Karen L.
Simmons, Brooke D.
Smethurst, R. J.
Lintott, Chris
Zalesky, Lukas
McPartland, Conor
Weaver, John R.
Toft, Sune
Sanders, Dave
Chartab, Nima
McCracken, Henry Joy
Mobasher, Bahram
Szapudi, Istvan
East, Noah
Turner, Wynne
Malkan, Matthew
Pearson, William J.
Goto, Tomotsugu
Oi, Nagisa
contents We present morphological classifications of over 41,000 galaxies out to $z_{\rm phot}\sim2.5$ across six square degrees of the Euclid Deep Field North (EDFN) from the Hawaii Twenty Square Degree (H20) survey, a part of the wider Cosmic Dawn survey. Galaxy Zoo citizen scientists play a crucial role in the examination of large astronomical data sets through crowdsourced data mining of extragalactic imaging. This iteration, Galaxy Zoo: Cosmic Dawn (GZCD), saw tens of thousands of volunteers and the deep learning foundation model Zoobot collectively classify objects in ultra-deep multiband Hyper Suprime-Cam (HSC) imaging down to a depth of $m_{HSC-i} = 21.5$. Here, we present the details and general analysis of this iteration, including the use of Zoobot in an active learning cycle to improve both model performance and volunteer experience, as well as the discovery of 51 new gravitational lenses in the EDFN. We also announce the public data release of the classifications for over 45,000 subjects, including more than 41,000 galaxies (median $z_{\rm phot}$ of $0.42\pm0.23$), along with their associated image cutouts. This data set provides a valuable opportunity for follow-up imaging of objects in the EDFN as well as acting as a truth set for training deep learning models for application to ground-based surveys like that of the Ultraviolet Near-Infrared Optical Northern Survey (UNIONS) collaboration and the newly operational Vera C. Rubin Observatory.
format Preprint
id arxiv_https___arxiv_org_abs_2509_22311
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Galaxy Zoo: Cosmic Dawn -- morphological classifications for over 41,000 galaxies in the Euclid Deep Field North from the Hawaii Two-0 Cosmic Dawn survey
Pearson, James
Dickinson, Hugh
Serjeant, Stephen
Walmsley, Mike
Fortson, Lucy
Kruk, Sandor
Masters, Karen L.
Simmons, Brooke D.
Smethurst, R. J.
Lintott, Chris
Zalesky, Lukas
McPartland, Conor
Weaver, John R.
Toft, Sune
Sanders, Dave
Chartab, Nima
McCracken, Henry Joy
Mobasher, Bahram
Szapudi, Istvan
East, Noah
Turner, Wynne
Malkan, Matthew
Pearson, William J.
Goto, Tomotsugu
Oi, Nagisa
Astrophysics of Galaxies
Instrumentation and Methods for Astrophysics
We present morphological classifications of over 41,000 galaxies out to $z_{\rm phot}\sim2.5$ across six square degrees of the Euclid Deep Field North (EDFN) from the Hawaii Twenty Square Degree (H20) survey, a part of the wider Cosmic Dawn survey. Galaxy Zoo citizen scientists play a crucial role in the examination of large astronomical data sets through crowdsourced data mining of extragalactic imaging. This iteration, Galaxy Zoo: Cosmic Dawn (GZCD), saw tens of thousands of volunteers and the deep learning foundation model Zoobot collectively classify objects in ultra-deep multiband Hyper Suprime-Cam (HSC) imaging down to a depth of $m_{HSC-i} = 21.5$. Here, we present the details and general analysis of this iteration, including the use of Zoobot in an active learning cycle to improve both model performance and volunteer experience, as well as the discovery of 51 new gravitational lenses in the EDFN. We also announce the public data release of the classifications for over 45,000 subjects, including more than 41,000 galaxies (median $z_{\rm phot}$ of $0.42\pm0.23$), along with their associated image cutouts. This data set provides a valuable opportunity for follow-up imaging of objects in the EDFN as well as acting as a truth set for training deep learning models for application to ground-based surveys like that of the Ultraviolet Near-Infrared Optical Northern Survey (UNIONS) collaboration and the newly operational Vera C. Rubin Observatory.
title Galaxy Zoo: Cosmic Dawn -- morphological classifications for over 41,000 galaxies in the Euclid Deep Field North from the Hawaii Two-0 Cosmic Dawn survey
topic Astrophysics of Galaxies
Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2509.22311