Euclid Quick Data Release (Q1). A systematic study of the intracluster light fraction at 0.2 < z < 1.5

@misc{collaboration2026euclid,
  title = {{Euclid Quick Data Release (Q1). A systematic study of the intracluster light fraction at 0.2 < z < 1.5}},
  author = {Euclid Collaboration and H. Gully and N. A. Hatch and H. Gao and S. P. Bamford and J. B. Golden-Marx and A. Fernandez and T. Kolcu and Y. M. Bahé and A. H. Gonzalez and M. Montes and M. Urbano and H. J. Brown and G. Martin and L. Moscardini and F. Durret and S. L. Ahad and J. G. Sorce and B. Altieri and S. Andreon and N. Auricchio and C. Baccigalupi and M. Baldi and S. Bardelli and P. Battaglia and A. Biviano and M. Bolzonella and E. Branchini and M. Brescia and S. Camera and V. Capobianco and C. Carbone and V. F. Cardone and J. Carretero and M. Castellano and G. Castignani and S. Cavuoti and K. C. Chambers and A. Cimatti and C. Colodro-Conde and G. Congedo and C. J. Conselice and L. Conversi and Y. Copin and A. Costille and F. Courbin and H. M. Courtois and M. Cropper and H. Degaudenzi and G. De Lucia and H. Dole and F. Dubath and X. Dupac and A. Ealet and S. Escoffier and M. Farina and R. Farinelli and F. Faustini and S. Ferriol and F. Finelli},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.29684},
  eprint = {2610.29684},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.29684},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Euclid Quick Data Release (Q1). A systematic study of the intracluster light fraction at 0.2 < z < 1.5
AU  - Euclid Collaboration
AU  - H. Gully
AU  - N. A. Hatch
AU  - H. Gao
AU  - S. P. Bamford
AU  - J. B. Golden-Marx
AU  - A. Fernandez
AU  - T. Kolcu
AU  - Y. M. Bahé
AU  - A. H. Gonzalez
AU  - M. Montes
AU  - M. Urbano
AU  - H. J. Brown
AU  - G. Martin
AU  - L. Moscardini
AU  - F. Durret
AU  - S. L. Ahad
AU  - J. G. Sorce
AU  - B. Altieri
AU  - S. Andreon
AU  - N. Auricchio
AU  - C. Baccigalupi
AU  - M. Baldi
AU  - S. Bardelli
AU  - P. Battaglia
AU  - A. Biviano
AU  - M. Bolzonella
AU  - E. Branchini
AU  - M. Brescia
AU  - S. Camera
AU  - V. Capobianco
AU  - C. Carbone
AU  - V. F. Cardone
AU  - J. Carretero
AU  - M. Castellano
AU  - G. Castignani
AU  - S. Cavuoti
AU  - K. C. Chambers
AU  - A. Cimatti
AU  - C. Colodro-Conde
AU  - G. Congedo
AU  - C. J. Conselice
AU  - L. Conversi
AU  - Y. Copin
AU  - A. Costille
AU  - F. Courbin
AU  - H. M. Courtois
AU  - M. Cropper
AU  - H. Degaudenzi
AU  - G. De Lucia
AU  - H. Dole
AU  - F. Dubath
AU  - X. Dupac
AU  - A. Ealet
AU  - S. Escoffier
AU  - M. Farina
AU  - R. Farinelli
AU  - F. Faustini
AU  - S. Ferriol
AU  - F. Finelli
PY  - 2026
DA  - 2026/10/21
PB  - arXiv
DO  - 10.48550/arxiv.2610.29684
UR  - https://arxiv.org/abs/2610.29684
AB  - We present a homogeneous analysis of the intracluster light (ICL) in approximately 300 galaxy clusters spanning 0.2<z<1.5, combining Sunyaev-Zeldovich-selected clusters from the South Pole Telescope and optically selected clusters from Euclid, and comparing results with Hydrangea simulations. We measured the brightest cluster galaxy (BCG) within elliptical isophotes of semi-major axis 50 kpc, and ICL between 50 and 200 kpc. We show that the Euclid Wide Survey can detect ICL in individual massive clusters (M_500 ≳ 10^14.2 M_⊙) out to at least z∼1.5, with detection rates of 70-80%. This indicates that diffuse stellar envelopes are common, although not ubiquitous, in massive clusters throughout this redshift range. Using a uniform methodology, we place improved constraints on ICL fraction evolution. ICL contributes about 40% of the combined BCG and ICL light and 20% of the total cluster stellar light, with both fractions remaining approximately constant across 0.2<z<1.5 at fixed cluster mass. This implies that the relative partitioning of stellar mass between the BCG, ICL, and satellite populations is largely established by z∼1.5. However, the ICL properties of individual clusters may still change as they evolve, since the sample does not represent an evolutionary sequence. This behaviour is consistent with a scenario in which the BCG and ICL are assembled together through the accretion, stripping, and eventual merging of the same population of massive galaxies (>10^10 M_⊙). The inferred ICL fraction also depends systematically on wavelength, while remaining largely insensitive to the adopted outer integration radius of 200-600 kpc. These results highlight the importance of homogeneous ICL analyses and constrain the evolution of diffuse stellar components in clusters.
ER  -