The Galactic globular cluster system as a fossil record of reionization

Abstract

We propose that structural, kinematical, and chemical properties of the Galactic globular clusters (GCs) can contain fossil information of the cosmic reionization history. We first summarize possible observational evidences for the influence of reionization on the Galactic GC formation. We then show how structural properties of the GC system (GCS) in the Galaxy can be influenced by suppression of GC formation due to reionization during the Galaxy formation through hierarchical merging of subgalactic clumps, by using numerical simulations with and without suppression of GC formation by reionization. In particular, we show that if GC formation in dwarf galaxies that are building blocks of the Galaxy and virialized after reionization era ($z_{reion}$) are completely suppressed, the present-day radial distribution of the Galactic GCs depends strongly on $z_{reion}$. Our numerical results imply that if GC formation after $z_{reion}$ $\sim$ 15 is strongly suppressed, the origin of the observed structural properties of the Galactic GCS can be more naturally explained in the framework of the hierarchical clustering scenario.

8 pages 3 figures (1 color jpg) ApJL in press (626, L93)

References in corpus (3)

• Comparing the properties of local globular cluster systems: implications for the formation of the Galactic halo
• Impact of Reionization on the Stellar Populations of Nearby Dwarf Galaxies
• Fossil records of cosmic reionization in galactic stellar halos

Cited by in corpus (19)

• The formation and hierarchical assembly of globular cluster populations
• Dark Matter Halos in Galaxies and Globular Cluster Populations. II: Metallicity and Morphology
• Kinematic Decoupling of Globular Clusters with Extended Horizontal-Branch
• The connection between globular cluster systems and their host galaxy and environment: a case study of the isolated elliptical NGC 821
• Globular Cluster Formation Within The Aquarius Simulation
• VLT-UVES abundance analysis of four giants in NGC 6553
• On spatial distributions of old globular clusters in clusters of galaxies
• Bimodal Galaxies and Bimodality in Globular Cluster Systems
• Globular Clusters Formed within Dark Halos I: present-day abundance, distribution and kinematics
• Formation of intracluster globular clusters
• Evidence for inhomogeneous reionization in the local Universe from metal-poor globular cluster systems
• Primordial pollution of globular clusters within their host dwarfs embedded in dark matter halos at high redshifts
• On the structure of globular cluster systems in elliptical galaxies
• Observational Biases Masquerading as Cosmological Effects? A Cautionary Tale about Blue Tilts and Other Trends in Globular Cluster Systems
• On the Origin of Mass--Metallicity Relations, Blue Tilts, and Scaling Relations for Metal-poor Globular Cluster Systems
• The U-shaped distribution of globular cluster specific frequencies in a biased globular cluster formation scenario
• On a possible origin for the lack of old star clusters in the Small Magellanic Cloud
• The inhomogenous reionization of the inter-galactic medium by metal-poor globular clusters
• On the Origin of the Kinematical Differences Between the Stellar Halo and the Old Globular Cluster System in the Large Magellanic Cloud