Euclid: Early Release Observations -- The intracluster light and intracluster globular clusters of the Perseus cluster
Authors: Kluge M. , Hatch N.A. , Montes M. , Golden-Marx J.B. , Gonzalez A.H. , Cuillandre J.-C. , Bolzonella M. , Lançon A. , Laureijs R. , Saifollahi T. , Schirmer M. , Stone C. , Boselli A. , Cantiello M. , Sorce J.G. , Marleau F.R. , Duc P.-A. , Sola E. , Urbano M. , Ahad S.L. , Bahé Y. M. , Bamford S.P. , Bellhouse C. , Buitrago F. , Dimauro P. , Durret F. , Ellien A. , Jimenez-Teja Y. , Slezak E. , Aghanim N. , Altieri B. , Andreon S. , Auricchio N. , Baldi M. , Balestra A. , Bardelli S. , Bender R. , Bonino D. , Branchini E. , Brescia M. , Brinchmann J. , Camera S. , Candini G.P. , Capobianco V. , Carbone C. , Carretero J. , Casas S. , Castellano M. , Cavuoti S. , Cimatti A. , Congedo G. , Conselice C.J. , Conversi L. , Copin Y. , Courbin F. , Courtois H.M. , Cropper M. , Da Silva A. , Degaudenzi H. , Dinis J. , Duncan C.A.J. , Dupac X. , Dusini S. , Farina M. , Farrens S. , Ferriol S. , Fosalba P. , Frailis M. , Franceschi E. , Fumana M. , Galeotta S. , Garilli B. , Gillard W. , Gillis B. , Giocoli C. , Gómez-Alvarez P. , Granett B.R. , Grazian A. , Grupp F. , Guzzo L. , Haugan S.V.H. , Hoar J. , Hoekstra H. , Holmes W. , Hook I. , Hormuth F. , Hornstrup A. , Hudelot P. , Jahnke K. , Keihänen E. , Kermiche S. , Kiessling A. , Kitching T. , Kohley R. , Kubik B. , Kümmel M. , Kunz M. , Kurki-Suonio H. , Lahav O. , Ligori S. , Lilje P.B. , Lindholm V. , Lloro I. , Maiorano E. , Mansutti O. , Marggraf O. , Markovic K. , Martinet N. , Marulli F. , Massey R. , Maurogordato S. , McCracken H.J. , Medinaceli E. , Mei S. , Melchior M. , Mellier Y. , Meneghetti M. , Merlin E. , Meylan G. , Moresco M. , Moscardini L. , Munari E. , Nichol R.C. , Niemi S.-M. , Nightingale J.W. , Padilla C. , Paltani S. , Pasian F. , Pedersen K. , Percival W.J. , Pettorino V. , Pires S. , Polenta G. , Poncet M. , Popa L.A. , Pozzetti L. , Racca G.D. , Raison F. , Rebolo R. , Renzi A. , Rhodes J. , Riccio G. , Rix H.-W. , Romelli E. , Roncarelli M. , Rossetti E. , Saglia R. , Sapone D. , Sartoris B. , Sauvage M. , Scaramella R. , Schneider P. , Schrabback T. , Secroun A. , Seidel G. , Seiffert M. , Serrano S. , Sirignano C. , Sirri G. , Skottfelt J. , Stanco L. , Tallada-Crespí P. , Taylor A.N. , Teplitz H.I. , Tereno I. , Toledo-Moreo R. , Torradeflot F. , Tutusaus I. , Valentijn E.A. , Valenziano L. , Vassallo T. , Verdoes Kleijn G. , Veropalumbo A. , Wang Y. , Weller J. , Williams O.R. , Zamorani G. , Zucca E. , Biviano A. , Burigana C. , De Lucia G. , George K. , Scottez V. , Simon P. , Mora A. , Martín-Fleitas J. , Ruppin F. , Scott D. 
Published: November 2024

We study the intracluster light (ICL) and intracluster globular clusters (ICGCs) in the nearby Perseus cluster of galaxies using Early Release Observations. By modelling the isophotal and iso-density contours, we mapped the distributions and properties of the ICL and ICGCs out to radii of $200$--$600$\,kpc (up to $ $ of the virial radius, depending on the parameter) from the brightest cluster galaxy (BCG).
We find that the central 500\,kpc of the Perseus cluster hosts $70\,000 globular clusters, and $1.7 odot $ of diffuse light from the BCG+ICL in the near-infrared This accounts for $38 of the cluster's total stellar luminosity within this radius. The ICL and ICGCs share a coherent spatial distribution which suggests that they have a common origin or that a common potential governs their distribution. Their contours on the largest scales ($>200$\,kpc) are not centred on the BCG's core, but are instead offset westwards by 60\,kpc towards several luminous cluster galaxies. This offset is opposite to the displacement observed in the gaseous intracluster medium. The radial surface brightness profile of the BCG+ICL is best described by a double S\'ersic model, with $68 of the light contained in the extended, outer component. The transition between these components occurs at approx 60\,kpc, beyond which the isophotes become increasingly elliptical and off-centred. Furthermore, the radial ICGC number density profile closely follows the profile of the BCG+ICL only beyond this 60\,kpc radius, where we find an average of 60--80 globular clusters per $10^9$\,M$_ of diffuse stellar mass. The BCG+ICL colour becomes increasingly blue with radius, consistent with the stellar populations in the ICL having subsolar metallicities Fe/H to $-1.0$. The colour of the ICL, and the specific frequency and luminosity function of the ICGCs suggest that the ICL+ICGCs were tidally stripped from the outskirts of massive satellites with masses of a few $ $\,M$_ with an increasing contribution from dwarf galaxies at large radii.