HST Photometry for the Halo Stars in the Leo Elliptical NGC 3377

Abstract

We have used the ACS camera on HST to obtain (V,I) photometry for 57,000 red-giant stars in the halo of the Leo elliptical NGC 3377. We use this sample of stars to derive the metallicity distribution function (MDF) for its halo field stars, and comment on its chemical evolution history compared with both larger and smaller E galaxies. Our ACS/WFC field spans a radial range extending from 4 to 18 kpc projected distance from the center of NGC 3377 and thus covers a significant portion of this galaxy's halo. We find that the MDF is broad, reaching a peak at [m/H] ~ -0.6$,butcontainingvirtuallynostarsmoremetal-poorthanlog[m/H]=-1.5$. It may, in addition, have relatively few stars more metal-rich than [m/H] = -0.3$, although interpretation of the high-metallicity end of the MDF is limited by photometric completeness that affects the detection of the reddest, most metal-rich stars. NGC 3377 appears to have an enrichment history intermediate between those of normal dwarf ellipticals and the much larger giants. As yet, we find no clear evidence that the halo of NGC 3377 contains a significant population of ``young'' (< 3 Gy) stars.

40 pages, 17 figures

References in corpus (13)

• The Photometric Performance and Calibration of the HST Advanced Camera For Surveys
• Feedback and metal enrichment in cosmological SPH simulations I. A model for chemical enrichment
• Complexity on Small Scales: The Metallicity Distribution of the Carina Dwarf Spheroidal Galaxy
• The Predicted Metallicity Distribution of Stars in Dwarf Spheroidal Galaxies
• A simple model for the evolution of disc galaxies: The Milky Way
• The calibration of the RGB Tip as a Standard Candle: Extension to Near Infrared colors and higher metallicity
• Deep ACS Imaging of the Halo of NGC 5128: Reaching the Horizontal Branch
• Metallicities, relative ages and kinematics of stellar populations in omega Centauri
• Homogeneous Photometry IV: On the Standard Sequence in the Globular Cluster NGC2419
• M31's Heavy Element Distribution and Outer Disk
• Virgo's Intracluster Globular Clusters as Seen by the Advanced Camera for Surveys
• Formation and evolution of late-type dwarf galaxies. I. NGC 1705 and NGC 1569
• Stochastic processes, galactic star formation, and chemical evolution. Effects of accretion, stripping, and collisions in multiphase multi-zone models

Cited by in corpus (34)

• The Distance to NGC 5128 (Centaurus A)
• The Auriga Stellar Haloes: Connecting stellar population properties with accretion and merging history
• Diverse Stellar Haloes in Nearby Milky Way-Mass Disc Galaxies
• The Inner Halo of M87: A First Direct View of the Red-Giant Population
• Chemical evolution of galaxies. I. A composition-dependent SPH model for chemical evolution and cooling
• The SLUGGS survey: Exploring the metallicity gradients of nearby early-type galaxies to large radii
• The Leo Elliptical NGC 3379: A Metal-Poor Halo Emerges
• The ACS Nearby Galaxy Survey Treasury I. The Star Formation History of the M81 Outer Disk
• How old are the stars in the halo of NGC 5128 (Centaurus A)?
• Infrared Tip of the Red Giant Branch and Distances to the Maffei/IC 342 Group
• Introducing the LBT Imaging of Galactic Halos and Tidal Structures (LIGHTS) survey. A preview of the low surface brightness Universe to be unveiled by LSST
• The Globular Cluster Systems around NGC 3311 and NGC 3309
• Testing galaxy formation models with the GHOSTS survey: The color profile of M81's stellar halo
• Nonlinear Color-Metallicity Relations of Globular Clusters. III. On the Discrepancy in Metallicity between Globular Cluster Systems and their Parent Elliptical Galaxies
• 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
• Dual Stellar Halos in the Standard Elliptical Galaxy M105 and Formation of Massive Early-Type Galaxies
• Detection of a distinct metal-poor stellar halo in the early-type galaxy NGC 3115
• Deep HST/ACS Photometry of the M81 Halo
• The Mass-Metallicity Relation of Globular Clusters in the Context of Nonlinear Color-Metallicty Relations
• The Outer Halo of the Nearest Giant Elliptical: A VLT/VIMOS Survey of the Resolved Stellar Populations in Centaurus A to 85 kpc
• Globular Cluster Systems of Early-type Galaxies in Low-density Environments
• UCD Candidates in the Hydra Cluster
• The Tip of the Red Giant Branch Distances to Type Ia Supernova Host Galaxies. III. NGC 4038/39 and NGC 5584
• New insights into the star formation histories of candidate intermediate-age early-type galaxies from K'-band imaging of globular clusters
• The Strikingly Metal-Rich Halo of the Sombrero Galaxy
• The ACS Nearby Galaxy Survey Treasury VI. The Ancient Star Forming disk of NGC 404
• The Tip of the Red Giant Branch Distances to Type Ia Supernova Host Galaxies. II. M66 and M96 in the Leo I Group
• The outermost stellar halo of NGC 5128 (Centaurus A): Radial structure
• 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
• 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
• Red giants in the outer halo of the elliptical galaxy NGC 5128 / Centaurus A
• Resolved Stellar Populations as Tracers of Outskirts
• A Glimpse into the Past: The Recent Evolution of Globular Clusters
• The Metallicity Distribution Function in Outer Halo Fields of Simulated Elliptical Galaxies Compared to Observations of NGC 5128