TY - JOUR
T1 - Euclid Quick Data Release (Q1): VIII. Exploring galaxy morphology across cosmic time through Sérsic fits
AU - Euclid Collaboration
AU - Quilley, L.
AU - Damjanov, I.
AU - de Lapparent, V.
AU - Paulino-Afonso, A.
AU - Domínguez Sánchez, H.
AU - Ferré-Mateu, A.
AU - Huertas-Company, M.
AU - Kümmel, M.
AU - Delley, D.
AU - Spiniello, C.
AU - Baes, M.
AU - Wang, L.
AU - Kuchner, U.
AU - Tarsitano, F.
AU - Ragusa, R.
AU - Siudek, M.
AU - Tortora, C.
AU - Aghanim, N.
AU - Altieri, B.
AU - Amara, A.
AU - Andreon, S.
AU - Auricchio, N.
AU - Aussel, H.
AU - Baccigalupi, C.
AU - Baldi, M.
AU - Balestra, A.
AU - Bardelli, S.
AU - Battaglia, P.
AU - Bender, R.
AU - Biviano, A.
AU - Bonchi, A.
AU - Bonino, D.
AU - Branchini, E.
AU - Brescia, M.
AU - Brinchmann, J.
AU - Camera, S.
AU - Cañas-Herrera, G.
AU - Capobianco, V.
AU - Carbone, C.
AU - Carretero, J.
AU - Casas, S.
AU - Castander, F. J.
AU - Castellano, M.
AU - Castignani, G.
AU - Cavuoti, S.
AU - Chambers, K. C.
AU - Percival, W. J.
AU - Schewtschenko, J. A.
AU - Gaztanaga, E.
AU - Naidoo, K.
N1 - Publisher Copyright:
© The Authors 2026. Open Access article, https://www.edpsciences.org, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This article is published in open access under the https://www.aanda.org/subscribe-to-open-faqs. mailto:[email protected] to support open access publication.
PY - 2026/7/1
Y1 - 2026/7/1
N2 - We present the results of the single-component Sérsic profile fitting for the magnitude-limited sample of IE < 23 galaxies within the 63.1 deg2 area of the Euclid Quick Data Release (Q1). The associated morphological catalogue includes two sets of structural parameters fitted using SourceXtractor++: one for VIS IE images and one for a combination of three NISP images in YE, JE, and HE bands. We compared the resulting Sérsic parameters to other morphological measurements provided in the Q1 data release and to the equivalent parameters based on higher-resolution Hubble Space Telescope imaging. These comparisons confirmed the consistency and the reliability of the fits to Q1 data. Our analysis of colour gradients shows that NISP profiles systematically have smaller effective radii (Re) and larger Sérsic indices (n) than in VIS. In addition, we highlight trends in NISP-to-VIS parameter ratios with both magnitude and nVIS. From the 2D bimodality of the (u − r) colour-log(n) plane, we defined a (u − r)lim(n) that separates early- and late-type galaxies (ETGs and LTGs). We used the two sub-populations to examine the variations of n across well-known scaling relations at z < 1. The ETGs display a steeper size–stellar mass relation than the LTGs, indicating a difference in the main drivers of their mass assembly. Similarly, LTGs and ETGs occupy different parts of the stellar mass–star-formation rate plane, with ETGs at higher masses than LTGs and further below the main sequence of star-forming galaxies. This clear separation highlights the link known between the shutdown of star formation and morphological transformations in the Euclid imaging data set. In conclusion, our analysis demonstrates both the robustness of the Sérsic fits available in the Q1 morphological catalogue and the wealth of information they provide for studies of galaxy evolution with Euclid.
AB - We present the results of the single-component Sérsic profile fitting for the magnitude-limited sample of IE < 23 galaxies within the 63.1 deg2 area of the Euclid Quick Data Release (Q1). The associated morphological catalogue includes two sets of structural parameters fitted using SourceXtractor++: one for VIS IE images and one for a combination of three NISP images in YE, JE, and HE bands. We compared the resulting Sérsic parameters to other morphological measurements provided in the Q1 data release and to the equivalent parameters based on higher-resolution Hubble Space Telescope imaging. These comparisons confirmed the consistency and the reliability of the fits to Q1 data. Our analysis of colour gradients shows that NISP profiles systematically have smaller effective radii (Re) and larger Sérsic indices (n) than in VIS. In addition, we highlight trends in NISP-to-VIS parameter ratios with both magnitude and nVIS. From the 2D bimodality of the (u − r) colour-log(n) plane, we defined a (u − r)lim(n) that separates early- and late-type galaxies (ETGs and LTGs). We used the two sub-populations to examine the variations of n across well-known scaling relations at z < 1. The ETGs display a steeper size–stellar mass relation than the LTGs, indicating a difference in the main drivers of their mass assembly. Similarly, LTGs and ETGs occupy different parts of the stellar mass–star-formation rate plane, with ETGs at higher masses than LTGs and further below the main sequence of star-forming galaxies. This clear separation highlights the link known between the shutdown of star formation and morphological transformations in the Euclid imaging data set. In conclusion, our analysis demonstrates both the robustness of the Sérsic fits available in the Q1 morphological catalogue and the wealth of information they provide for studies of galaxy evolution with Euclid.
KW - galaxies: evolution
KW - galaxies: statistics
KW - galaxies: structure
UR - https://www.scopus.com/pages/publications/105043553475
U2 - 10.1051/0004-6361/202554585
DO - 10.1051/0004-6361/202554585
M3 - Article
AN - SCOPUS:105043553475
SN - 0004-6361
VL - 711
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A8
ER -