Euclid 项目：IC 342、NGC 2403 与 Holmberg II 中的星团
摘要
本文考察了三座靠近星系 IC 342、NGC 2403 和 Holmberg II 中的星团 population，这些星系作为 Euclid Early Release Observations 计划的一部分被观测。我们的主要关注对象是老型星团 (GC)，由于 Euclid 的宽视场和卓越图像质量，相较于以往工作具有显著优势。对于 IC 342 而言，这是首次研究除其核星团之外的恒星星团。根据基于大小和星等标准的选择， followed by visual 检查，我们在 IC 342 中识别出 111 个老型 (> 1 Gyr) GC 候选星团，NGC 2403 中为 50 个 (其中 15 个先前已知)，Holmberg II 中为 7 个。此外，还识别出若干较年轻和/或中间年龄的候选星团。两个较大星系中 GC 候选星团的颜色分布显示出 hints of bimodal，峰值分别位于 IE-HE = 0.36 和 0.79 (IC 342) 和 IE-HE = 0.36 和 0.80 (NGC 2403)，对应金属度 [Fe/H]=-1.5 和 [Fe/H]=-0.5，类似于银河系的金属贫 and 金属富 GC 亚种群。我们 GC 候选星团的光度函数显示出相对典型约为高斯形 GC luminosity function (GCLF) 的较弱对象的 excess。这些 excess 对象可能类似于在其他星系中先前识别出的对象。基于 GCLF 中较亮的一半， IC 342 的经典老型 GC 的 specific frequency 似乎异常低，SN=0.2-0.3。所有三座星系中年轻 and 中间年龄星团的组合光度函数与 power-law 分布一致，dN/dL ~ L^(-2.3+/-0.1)，而 NGC 2403 和 Holmberg II 中亮于 M(IE)=-8 的年轻星团数量，与其 Local Group 对手 (M33 和小银河系) 的数量相当。
引用
@article{arxiv.2503.16637,
title = {Euclid: Star clusters in IC 342, NGC 2403, and Holmberg II},
author = {S. S. Larsen and A. M. N. Ferguson and J. M. Howell and F. Annibali and J. -C. Cuillandre and L. K. Hunt and A. Lançon and T. Saifollahi and D. Massari and M. N. Le and N. Aghanim and B. Altieri and A. Amara and S. Andreon and N. Auricchio and C. Baccigalupi and M. Baldi and A. Balestra and S. Bardelli and P. Battaglia and A. Biviano and E. Branchini and M. Brescia and J. Brinchmann and S. Camera and V. Capobianco and C. Carbone and J. Carretero and S. Casas 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 F. Courbin and H. M. Courtois and M. Cropper and A. Da Silva and H. Degaudenzi and G. De Lucia and H. Dole and M. Douspis and F. Dubath and X. Dupac and S. Dusini and S. Escoffier and M. Fabricius and M. Farina and F. Faustini and S. Ferriol and S. Fotopoulou and M. Frailis and E. Franceschi and S. Galeotta and K. George and B. Gillis and C. Giocoli and P. Gómez-Alvarez and J. Gracia-Carpio and A. Grazian and F. Grupp and S. V. H. Haugan and H. Hoekstra and W. Holmes and F. Hormuth and A. Hornstrup and K. Jahnke and M. Jhabvala and E. Keihänen and S. Kermiche and A. Kiessling and R. Kohley and B. Kubik and K. Kuijken and M. Kümmel and M. Kunz and H. Kurki-Suonio and A. M. C. Le Brun and S. Ligori and P. B. Lilje and V. Lindholm and I. Lloro and D. Maino and E. Maiorano and O. Mansutti and O. Marggraf and K. Markovic and M. Martinelli and N. Martinet and F. Marulli and R. Massey and E. Medinaceli and S. Mei and Y. Mellier and M. Meneghetti and G. Meylan and A. Mora and M. Moresco and L. Moscardini and C. Neissner and S. -M. Niemi and C. Padilla and S. Paltani and F. Pasian and K. Pedersen and W. J. Percival and V. Pettorino and S. Pires and G. Polenta and M. Poncet and L. A. Popa and L. Pozzetti and F. Raison and A. Renzi and J. Rhodes and G. Riccio and E. Romelli and M. Roncarelli and R. Saglia and Z. Sakr and D. Sapone and B. Sartoris and J. A. Schewtschenko and M. Schirmer and P. Schneider and A. Secroun and G. Seidel and M. Seiffert and S. Serrano and P. Simon and C. Sirignano and G. Sirri and J. Skottfelt and L. Stanco and J. Steinwagner and P. Tallada-Crespí and A. N. Taylor and I. Tereno and R. Toledo-Moreo and F. Torradeflot and A. Tsyganov and I. Tutusaus and L. Valenziano and J. Valiviita and T. Vassallo and G. Verdoes Kleijn and A. Veropalumbo and Y. Wang and J. Weller and G. Zamorani and F. M. Zerbi and E. Zucca and J. Martín-Fleitas and V. Scottez},
journal= {arXiv preprint arXiv:2503.16637},
year = {2025}
}
备注
Submitted to A&A following internal review