Euclid: Early Release Observations -- Deep anatomy of nearby galaxies
Abstract
Euclid is poised to make significant advances in the study of nearby galaxies in the local Universe. Here we present a first look at 6 galaxies observed for the Nearby Galaxy Showcase as part of the Euclid Early Release Observations acquired between August and November, 2023. These targets, 3 dwarf galaxies (HolmbergII, IC10, NGC6822) and 3 spirals (IC342, NGC2403, NGC6744), range in distance from about 0.5 Mpc to 8.8 Mpc. Our assessment of the surface brightness depths in the stacked Euclid images confirms previous estimates in 100 arcsec^2 regions of 1sigma=30.5 mag/arcsec^2 for VIS, but slightly deeper than previous estimates for NISP with 1sigma=29.2-29.4 mag/arcsec^2. By combining Euclid HE, YE, and IE into RGB images, we illustrate the large field-of-view covered by a single Reference Observing Sequence, together with exquisite detail on parsec scales in these nearby galaxies. Radial surface brightness and color profiles demonstrate galaxy colors in agreement with stellar population synthesis models. Standard stellar photometry selection techniques find approximately 1.3 million stars across the 6 galaxy fields. Euclid's resolved stellar photometry allows us to constrain the star-formation histories of these galaxies, by disentangling the distributions of young stars, as well as asymptotic giant branch and red giant branch stellar populations. We finally examine 2 galaxies individually for surrounding satellite systems. Our analysis of the ensemble of dwarf satellites around NGC6744 reveals a new galaxy, EDwC1, a nucleated dwarf spheroidal at the end of a spiral arm. Our new census of the globular clusters around NGC2403 yields 9 new star-cluster candidates, 8 of which with colors indicative of evolved stellar populations. In summary, our investigation of the 6 Showcase galaxies demonstrates that Euclid is a powerful probe of the anatomy of nearby galaxies [abridged].
Keywords
Cite
@article{arxiv.2405.13499,
title = {Euclid: Early Release Observations -- Deep anatomy of nearby galaxies},
author = {L. K. Hunt and F. Annibali and J. -C. Cuillandre and A. M. N. Ferguson and P. Jablonka and S. S. Larsen and F. R. Marleau and E. Schinnerer and M. Schirmer and C. Stone and C. Tortora and T. Saifollahi and A. Lançon and M. Bolzonella and S. Gwyn and M. Kluge and R. Laureijs and D. Carollo and M. L. M. Collins and P. Dimauro and P. -A. Duc and D. Erkal and J. M. Howell and C. Nally and E. Saremi and R. Scaramella and V. Belokurov and C. J. Conselice and J. H. Knapen and A. W. McConnachie and I. McDonald and J. Miro Carretero and J. Roman and M. Sauvage and E. Sola and N. Aghanim and B. Altieri and S. Andreon and N. Auricchio and S. Awan and R. Azzollini and M. Baldi and A. Balestra and S. Bardelli and A. Basset and R. Bender and D. Bonino and E. Branchini and M. Brescia and J. Brinchmann and S. Camera and G. P. Candini and V. Capobianco and C. Carbone and J. Carretero and S. Casas and M. Castellano and S. Cavuoti and A. Cimatti and G. Congedo and L. Conversi and Y. Copin and L. Corcione and F. Courbin and H. M. Courtois and M. Cropper and A. Da Silva and H. Degaudenzi and A. M. Di Giorgio and J. Dinis and F. Dubath and X. Dupac and S. Dusini and M. Farina and S. Farrens and S. Ferriol and P. Fosalba and M. Frailis and E. Franceschi and M. Fumana and S. Galeotta and B. Garilli and W. Gillard and B. Gillis and C. Giocoli and P. Gómez-Alvarez and B. R. Granett and A. Grazian and F. Grupp and L. Guzzo and S. V. H. Haugan and J. Hoar and H. Hoekstra and M. S. Holliman and W. Holmes and I. Hook and F. Hormuth and A. Hornstrup and P. Hudelot and K. Jahnke and E. Keihänen and S. Kermiche and A. Kiessling and M. Kilbinger and T. Kitching and R. Kohley and B. Kubik and K. Kuijken and M. Kümmel and M. Kunz and H. Kurki-Suonio and O. Lahav and D. Le Mignant and P. B. Lilje and V. Lindholm and I. Lloro and E. Maiorano and O. Mansutti and O. Marggraf and K. Markovic and N. Martinet and F. Marulli and R. Massey and S. Maurogordato and H. J. McCracken and E. Medinaceli and S. Mei and Y. Mellier and M. Meneghetti and E. Merlin and G. Meylan and M. Moresco and L. Moscardini and E. Munari and R. Nakajima and R. C. Nichol and S. -M. Niemi and J. W. Nightingale 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 G. D. Racca and F. Raison and R. Rebolo and A. Refregier and A. Renzi and J. Rhodes and G. Riccio and E. Romelli and M. Roncarelli and E. Rossetti and R. Saglia and D. Sapone and B. Sartoris and P. Schneider and T. Schrabback and M. Scodeggio and A. Secroun and G. Seidel and S. Serrano and C. Sirignano and G. Sirri and J. Skottfelt and L. Stanco and P. Tallada-Crespí and D. Tavagnacco and A. N. Taylor and H. I. Teplitz and I. Tereno and R. Toledo-Moreo and F. Torradeflot and I. Tutusaus and E. A. Valentijn and L. Valenziano and T. Vassallo and G. Verdoes Kleijn and A. Veropalumbo and Y. Wang and J. Weller and O. R. Williams and G. Zamorani and E. Zucca and C. Burigana and G. De Lucia and K. George and V. Scottez and M. Miluzio and P. Simon and A. Mora and J. Martín-Fleitas and D. Scott},
journal= {arXiv preprint arXiv:2405.13499},
year = {2025}
}
Comments
36 pages; 20 figures in main text; 4 Appendices. Submitted to A&A, as part of the A&A special issue `Euclid on Sky', which contains Euclid key reference papers and first results from the Euclid Early Release Observations