Dual Stellar Halos in the Standard Elliptical Galaxy M105 and Formation of Massive Early-Type Galaxies

Abstract

M105 is a standard elliptical galaxy, located in the Leo I Group. We present photometry of the resolved stars in its inner region at R ~ 4' ~ 4Reff, obtained from F606W and F814W images in the Hubble Space Telescope archive. We combine this with photometry of the outer region at R ~ 12' ~ 12Reff from archival imaging data. Color-magnitude diagrams of the resolved stars in the inner region show a prominent red giant branch (RGB) with a large color range, while those of the outer region show better a narrow blue RGB. The metallicity distribution function (MDF) of the RGB stars shows the existence of two distinct subpopulations: a dominant metal-rich population (with a peak at [M/H] ~ 0.0) and a much weaker metal-poor population (with a peak at [M/H] ~ -1.1). The radial number density profiles of the metal-rich and metal-poor RGB stars are fit well by a Sersic law with n=2.75+-0.10 and n=6.89+-0.94, and by a single power law, respectively. The MDFs of the inner and outer regions can be described well by accretion gas models of chemical evolution with two components. These provide strong evidence that there are two distinct stellar halos in this galaxy, metal-poor and red metal-rich halos, consistent with the results based on globular cluster systems in bright early-type galaxies (Park & Lee 2013). We discuss the implications of these results with regard to the formation of massive early-type galaxies in the dual halo mode formation scenario.

17 pages, 13 figures, and 7 tables ; Accepted for publication in ApJ

References in corpus (16)

• The Dartmouth Stellar Evolution Database
• The hierarchical formation of the brightest cluster galaxies
• Physical Models of Galaxy Formation in a Cosmological Framework
• HyperLEDA. III. The catalogue of extragalactic distances
• The ACS Virgo Cluster Survey XV. The Formation Efficiencies of Globular Clusters in Early-Type Galaxies: The Effects of Mass and Environment
• The Quenching of the Ultra-Faint Dwarf Galaxies in the Reionization Era
• Formation of In Situ Stellar Haloes in Milky Way-Mass Galaxies
• The stellar accretion origin of stellar population gradients in massive galaxies at large radii
• The Metallicity Distribution of Intracluster Stars in Virgo
• Isochrones for Old (> 5 Gyr) Stars and Stellar Populations. I. Models for $-2.4\le$ [Fe/H] $\le +0.6$, $0.25\le Y\le 0.33$, and $-0.4\le$ [$\alpha$\Fe] $\le +0.4$
• Hiding in plain sight: An abundance of compact massive spheroids in the local Universe
• Tracing the outer halo in a giant elliptical to 25 Reff
• Detection of a distinct metal-poor stellar halo in the early-type galaxy NGC 3115
• Discovery of an Ultra-Faint Dwarf Galaxy in the Intracluster Field of the Virgo Center : A fossil of the First Galaxies?
• NGC 5011C: an overlooked dwarf galaxy in the Centaurus A group
• Red giants in the outer halo of the elliptical galaxy NGC 5128 / Centaurus A

Cited by in corpus (29)

• The Tip of the Red Giant Branch Distances to Type Ia Supernova Host Galaxies. IV. Color Dependence and Zero-Point Calibration
• An old, metal-poor globular cluster in Sextans A and the metallicity floor of globular cluster systems
• The difference in metallicity distribution functions of halo stars and globular clusters as a function of galaxy type: A tracer of globular cluster formation and evolution
• The Survey of Centaurus A's Baryonic Structures (SCABS). II. The Extended Globular Cluster System of NGC5128 and its Nearby Environment
• Astrophysical Distance Scale II. Application of the JAGB Method: A Nearby Galaxy Sample
• NGC 5128 globular cluster candidates out to 150 kpc: a comprehensive catalog from Gaia and ground based data
• Euclid: Early Release Observations -- The intracluster light and intracluster globular clusters of the Perseus cluster
• Tracing the anemic stellar halo of M101
• Evidence for Optically Thick, Eddington-limited Winds Driven by Supercritical Accretion
• The Strikingly Metal-Rich Halo of the Sombrero Galaxy
• Kinematics of the diffuse intragroup and intracluster light in groups and clusters of galaxies in the Local Universe within 100 Mpc distance
• Minor Mergers are not enough: The importance of Major Mergers during Brightest Cluster Galaxy assembly
• Nonlinear Color-Metallicity Relations of Globular Clusters. VIII. Reproducing Color Distributions of Individual Globular Cluster Systems in the Virgo and Fornax Galaxy Clusters
• The halo of M105 and its group environment as traced by planetary nebula populations: I. Wide-field photometric survey of planetary nebulae in the Leo I group
• Scaling relations for globular cluster systems in early-type galaxies. II. Is there an environmental dependence?
• Galaxies with Shells in the Illustris Simulation: Metallicity Signatures
• The halo of M105 and its group environment as traced by planetary nebula populations: II. Using kinematics of single stars to unveil the presence of intragroup light around the Leo I galaxies NGC 3384 and M105
• A Globular Cluster Luminosity Function Distance to NGC 4993 Hosting a Binary Neutron Star Merger GW170817/GRB 170817A
• The Distance and Dynamical History of the Virgo Cluster Ultradiffuse Galaxy VCC 615
• Resolving the Discrepancy of Distance to M60, a Giant Elliptical Galaxy in Virgo
• Mirach's Goblin: Discovery of a dwarf spheroidal galaxy behind the Andromeda galaxy
• Measuring Star Formation Histories, Distances, and Metallicities with Pixel Color-Magnitude Diagrams II: Applications to Nearby Elliptical Galaxies
• Tests of photometry: the case of the NGC 3370 ACS field
• Surface Brightness Fluctuations to constrain secondary stellar populations: Revealing very low-metallicity stars in massive galaxies
• Tracing the Giant Outer Halo of the Mysterious Massive Disk Galaxy M104 I. Photometry of the Extended Globular Cluster Systems
• Nonlinear Color-Metallicity Relations of Globular Clusters. IX. Different Radial Number Density Profiles between Blue and Red Clusters
• Widespread Shocks in the Nucleus of NGC 404 Revealed by Near-infrared Integral Field Spectroscopy
• The pride of lions around Messier 105
• The Metallicity Distribution Function in Outer Halo Fields of Simulated Elliptical Galaxies Compared to Observations of NGC 5128