Metallicities of Outer Halo M31 Globular Clusters from Integrated Light Calcium-II Triplet Spectroscopy

Abstract

This paper presents [Fe/H] ratios for GCs in the outer halo of the Andromeda Galaxy, M31, based on moderate-resolution, integrated light (IL) spectroscopy of the calcium-II triplet (CaT) lines. The CaT strengths are measured by fitting Voigt profiles to the lines and integrating those profiles; integrations of defined bandpasses are also considered. The [Fe/H] ratios are determined using an empirical calibration with CaT line strength, as derived from another sample of M31 GCs that were previously studied at high-resolution. The [Fe/H] ratios for the new GCs reveal that the outer halo GCs are indeed generally more metal-poor than typical inner halo GCs, though there are several more metal-rich GCs that look to have been accreted from dwarf satellites. The metallicities of these GCs also place important constraints on the nature of the substructure in the outer halo and the dwarf satellites that created this substructure.

arXiv commentAccepted for publication in MNRAS

References in corpus (77)

• Parametric Recovery of Line-of-Sight Velocity Distributions from Absorption-Line Spectra of Galaxies via Penalized Likelihood
• The observed properties of dwarf galaxies in and around the Local Group
• Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
• The remnants of galaxy formation from a panoramic survey of the region around M31
• A giant stream of metal-rich stars in the halo of the galaxy M31
• Evidence for Stellar Substructure in the Halo and Outer Disk of M31
• The Haunted Halos of Andromeda and Triangulum: A panorama of galaxy formation in action
• The Panchromatic Hubble Andromeda Treasury
• Empirical calibration of the near-IR Ca II triplet - I. The stellar library and index definition
• A Catalog of Globular Cluster Systems: What Determines the Size of a Galaxy's Globular Cluster Population?
• A Comparison of Elemental Abundance Ratios in Globular Clusters, Field Stars, and Dwarf Spheroidal Galaxies
• The large-scale structure of the halo of the Andromeda Galaxy Part I: global stellar density, morphology and metallicity properties
• On the accretion origin of a vast extended stellar disk around the Andromeda galaxy
• The NIR Ca II triplet at low metallicity - Searching for extremely low-metallicity stars in classical dwarf galaxies
• Analysis and calibration of CaII triplet spectroscopy of Red Giant Branch stars from VLT/FLAMES observations
• Mayall II = G1 in M31: Giant Globular Cluster or Core of a Dwarf Elliptical Galaxy ?
• Chemistry of the Sagittarius Dwarf Galaxy: a Top-Light IMF, Outflows and the R-Process
• The Metal-Poor Halo of the Andromeda Spiral Galaxy (M31)
• PAndAS' progeny: extending the M31 dwarf galaxy cabal
• The large-scale structure of the halo of the Andromeda galaxy II. Hierarchical structure in the Pan-Andromeda Archaeological Survey
• Evidence for an accretion origin for the outer halo globular cluster system of M31
• Explaining the Color Distributions of Globular Cluster Systems in Elliptical Galaxies
• Star Clusters in M31: II. Old Cluster Metallicities and Ages from Hectospec Data
• Inferring the Andromeda Galaxy's mass from its giant southern stream with Bayesian simulation sampling
• VLT/UVES Spectroscopy of Individual Stars in Three Globular Clusters in the Fornax Dwarf Spheroidal Galaxy
• The E-MOSAICS project: tracing galaxy formation and assembly with the age-metallicity distribution of globular clusters
• A 2-3 billion year old major merger paradigm for the Andromeda galaxy and its outskirts
• Star Clusters in M31: I. A Catalog and a Study of the Young Clusters
• A new population of extended, luminous star clusters in the halo of M31
• The SLUGGS Survey: Calcium Triplet-based Spectroscopic Metallicities for Over 900 Globular Clusters
• The outer halo globular cluster system of M31 - I. The final PAndAS catalogue
• Investigating the Andromeda Stream: II. Orbital Fits and Properties of the Progenitor
• The outer halo globular cluster system of M31 - II. Kinematics
• The Identification of Blue Horizontal Branch Stars in the Integrated Spectra of Globular Clusters
• The Stellar Populations of M31 Halo Substructure
• Panchromatic Hubble Andromeda Treasury XVIII. The High-mass Truncation of the Star Cluster Mass Function
• Global Properties of M31's Stellar Halo from the SPLASH Survey: II. Metallicity Profile
• Globular Cluster Abundances from High-Resolution Integrated Light Spectra, I: 47 Tuc
• M31 Globular Cluster Abundances from High-Resolution, Integrated-Light Spectroscopy
• Global Properties of `Ordinary' Early-type Galaxies: photometry and spectroscopy of stars and globular clusters in NGC 4494
• Star Clusters in M31. V. Evidence for Self-Enrichment in Old M31 Clusters from Integrated Spectroscopy
• The Detailed Chemical Properties of M31 Star Clusters I. Fe, Alpha and Light Elements
• Star Clusters in M31: VII. Global Kinematics and Metallicity Subpopulations of the Globular Clusters
• The SLUGGS Survey: Measuring globular cluster ages using both photometry and spectroscopy
• The outer halo globular cluster system of M31 - III. Relationship to the stellar halo
• Fossil stellar streams and their globular cluster populations in the E-MOSAICS simulations
• Young accreted globular clusters in the outer halo of M31
• Predicting accreted satellite galaxy masses and accretion redshifts based on globular cluster orbits in the E-MOSAICS simulations
• Major Substructure in the M31 Outer Halo: Distances and Metallicities along the Giant Stellar Stream
• Integrated Light Chemical Tagging Analyses of Seven M31 Outer Halo Globular Clusters from the Pan-Andromeda Archaeological Survey
• Two major accretion epochs in M31 from two distinct populations of globular clusters
• Keck Spectroscopy of Red Giant Stars in the Vicinity of M31's Massive Globular Cluster G1
• The Ca II triplet in red giant spectra: [Fe/H] determinations and the role of [Ca/Fe]
• Spectrum Syntheses of High Resolution Integrated Light Spectra of Galactic Globular Clusters
• Infrared High-Resolution Integrated Light Spectral Analyses of M31 Globular Clusters from APOGEE
• Star Clusters in M 31. IV. A Comparative Analysis of Absorption Line Indices in Old M 31 and Milky Way Clusters
• Stellar Stream and Halo Structure in the Andromeda Galaxy From a Subaru/Hyper Suprime-Cam Survey
• Formation of the Andromeda Giant Stream: Asymmetric Structure and Disc Progenitor
• The WAGGS project - II. The reliability of the calcium triplet as a metallicity indicator in integrated stellar light
• An extremely metal-deficient globular cluster in the Andromeda Galaxy
• Elemental Abundances in M31: Gradients in the Giant Stellar Stream
• Hubble Space Telescope analysis of stellar populations within the globular cluster G1 (Mayall II) in M31
• Major Substructure in the M31 Outer Halo: the South-West Cloud
• The LAMOST spectroscopic survey of star clusters in M31. II. Metallicities, ages and masses
• The kinematic footprints of five stellar streams in Andromeda's halo
• Optimal Integrated Abundances for Chemical Tagging of Extragalactic Globular Clusters
• Evidence for a chemical enrichment coupling of globular clusters and field stars in the Fornax dSph
• Estimating ages and metallicities of M31 star clusters from LAMOST DR6
• The Integrated Calcium II Triplet as a Metallicity Indicator: Comparisons with High Resolution [Fe/H] in M31 Globular Clusters
• Major Substructure in the M31 Outer Halo: the East Cloud
• The Massive M31 Cluster G1: Detailed Chemical Abundances from Integrated Light Spectroscopy
• Globular Clusters in the Outer Halo of M31
• The nature of the progenitor of the M31 North-western stream: globular clusters as milestones of its orbit
• Hubble Space Telescope imaging of the extremely metal-poor globular cluster EXT8 in Messier 31
• A Dwarf Disrupting -- Andromeda XXVII and the North West Stream
• Modelling of integrated-light spectra from the optical to the near-infrared: the globular cluster G280 in M31
• The nature of the Eastern Extent in the outer halo of M31

Cited by in corpus (5)

• Elemental abundances in M31: Individual and Coadded Spectroscopic [Fe/H] and [α/Fe] throughout the M31 Halo with SPLASH
• Revisiting the near infrared Calcium triplet as metallicity indicator
• On the Use of Field RR Lyrae as Galactic Probes -- VIII. Early Formation of the Galactic Spheroid
• Synthetic stellar spectra to study multiple populations in globular clusters: an extended grid and the effects on the integrated light
• Properties of the Lower Segment of M31's North West Stream