The Next Generation Virgo Cluster Survey. XXXIII. Stellar Population Gradients in the Virgo Cluster Core Globular Cluster System - Aix-Marseille Université Access content directly
Journal Articles Astrophys.J. Year : 2022

The Next Generation Virgo Cluster Survey. XXXIII. Stellar Population Gradients in the Virgo Cluster Core Globular Cluster System

Youkyung Ko
  • Function : Author
Eric W. Peng
  • Function : Author
Patrick Côté
  • Function : Author
Laura Ferrarese
  • Function : Author
Chengze Liu
  • Function : Author
Alessia Longobardi
  • Function : Author
Roberto P. Muñoz
  • Function : Author
Thomas H. Puzia
  • Function : Author
Karla A. Alamo-Martínez
  • Function : Author
Laura V. Sales
  • Function : Author
Felipe Ramos-Almendares
  • Function : Author
Mario G. Abadi
  • Function : Author
Myung Gyoon Lee
  • Function : Author
Ho Seong Hwang
Nelson Caldwell
John P. Blakeslee
  • Function : Author
Susana Eyheramendy
  • Function : Author
Puragra Guhathakurta
  • Function : Author
Stephen Gwyn
Andrés Jordán
  • Function : Author
Sungsoon Lim
Rubén Sánchez-Janssen
Elisa Toloba
  • Function : Author

Abstract

We present a study of the stellar populations of globular clusters (GCs) in the Virgo Cluster core with a homogeneous spectroscopic catalog of 692 GCs within a major-axis distance R $_{maj}$ = 840 kpc from M87. We investigate radial and azimuthal variations in the mean age, total metallicity, Fe/H , and α-element abundance of blue (metal-poor) and red (metal-rich) GCs using their co-added spectra. We find that the blue GCs have a steep radial gradient in Z/H within R $_{maj}$ = 165 kpc, with roughly equal contributions from Fe/H and α/Fe , and flat gradients beyond. By contrast, the red GCs show a much shallower gradient in Z/H , which is entirely driven by Fe/H . We use GC-tagged Illustris simulations to demonstrate an accretion scenario where more massive satellites (with more metal- and α-rich GCs) sink further into the central galaxy than less massive ones, and where the gradient flattening occurs because of the low GC occupation fraction of low-mass dwarfs disrupted at larger distances. The dense environment around M87 may also cause the steep α/Fe gradient of the blue GCs, mirroring what is seen in the dwarf galaxy population. The progenitors of red GCs have a narrower mass range than those of blue GCs, which makes their gradients shallower. We also explore spatial inhomogeneity in GC abundances, finding that the red GCs to the northwest of M87 are slightly more metal-rich. Future observations of GC stellar population gradients will be useful diagnostics of halo merger histories.
Fichier principal
Vignette du fichier
Ko_2022_ApJ_931_120.pdf (2.28 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

hal-03659540 , version 1 (17-03-2023)

Licence

Attribution

Identifiers

Cite

Youkyung Ko, Eric W. Peng, Patrick Côté, Laura Ferrarese, Chengze Liu, et al.. The Next Generation Virgo Cluster Survey. XXXIII. Stellar Population Gradients in the Virgo Cluster Core Globular Cluster System. Astrophys.J., 2022, 931 (2), pp.120. ⟨10.3847/1538-4357/ac63cf⟩. ⟨hal-03659540⟩
46 View
5 Download

Altmetric

Share

Gmail Facebook X LinkedIn More