Spatially Resolved Spectroscopic Star Formation Histories of Nearby Disks: Hints of Stellar Migration

Abstract

We use the Mitchell Spectrograph (formerly VIRUS-P) to observe 12 nearby disk galaxies. We successfully measure ages in the outer disk in six systems. In three cases (NGC 2684, NGC 6155, and NGC 7437), we find that a downward break in the disk surface brightness profile corresponds with a change in the dominant stellar population with the interior being dominated by active star formation and the exterior having older stellar populations that are best-fit with star formation histories that decline with time. The observed increase in average stellar ages beyond a profile break is similar to theoretical models that predict surface brightness breaks are caused by stellar migration, with the outer disk being populated from scattered old interior stars. In three more cases (IC 1132, NGC 4904, and NGC 6691), we find no significant change in the stellar population as one crosses the break radius. In these galaxies, both the inner and outer disks are dominated by active star formation and younger stellar populations. While radial migration can contribute to the stellar populations beyond the break, it appears more than one mechanism is required to explain all of our observed stellar profile breaks.

18 pages, 21 figures. Accepted for publication in ApJ

References in corpus (18)

• Riding the Spiral Waves: Implications of Stellar Migration for the Properties of Galactic Disks
• A Search for Extended Ultraviolet Disk (XUV-disk) Galaxies in the Local Universe
• The structure of galactic disks: Studying late-type spiral galaxies using SDSS
• Recovering galaxy star formation and metallicity histories from spectra using VESPA
• Color Profiles of Spiral Galaxies: Clues on Outer-Disk Formation Scenarios
• On the interpretation of age and chemical composition of composite stellar populations determined with line-strength indices
• Stellar Population and Kinematic Profiles in Spiral Bulges & Disks: Population Synthesis of Integrated Spectra
• Antitruncated Stellar Disks via Minor Mergers
• The ACS Nearby Galaxy Survey Treasury V. Radial Star Formation History of NGC 300
• Stellar populations across the NGC4244 truncated galactic disk
• Lick Indices in the Thin and Thick Disks of Edge-On Disk Galaxies
• The ACS Nearby Galaxy Survey Treasury I. The Star Formation History of the M81 Outer Disk
• On The Extended Knotted Disks of Galaxies
• Absorption line-strengths of 18 late-type spiral galaxies observed with SAURON
• The Stellar Populations of M33's Outer Regions III: Star Formation History
• The Stellar Populations of M33's Outer Regions IV: Inflow History and Chemical Evolution
• Disk galaxies with broken luminosity profiles from cosmological simulations
• Bimodality in low luminosity E and S0 galaxies

Cited by in corpus (47)

• The age structure of stellar populations in the solar vicinity. Clues of a two-phase formation history of the Milky Way disk
• Secular Evolution in Disk Galaxies
• Inside Out and Upside Down: Tracing the Assembly of a Simulated Disk Galaxy Using Mono-Age Stellar Populations
• Stellar Population gradients in galaxy discs from the CALIFA survey
• Evolution of Galactic Discs: Multiple Patterns, Radial Migration and Disc Outskirts
• The star formation history of CALIFA galaxies: Radial structures
• Radial Migration in Disk Galaxies I: Transient Spiral Structure and Dynamics
• Signatures of radial migration in barred galaxies: Azimuthal variations in the metallicity distribution of old stars
• Insights into the content and spatial distribution of dust from the integrated spectral properties of galaxies
• The impact of bars on disk breaks as probed by S4G imaging
• SDSS-IV MaNGA: environmental dependence of stellar age and metallicity gradients in nearby galaxies
• LZIFU: an emission-line fitting toolkit for integral field spectroscopy data
• The Rich Are Different: Evidence from the RAVE Survey for Stellar Radial Migration
• Outer-Disk Populations in NGC 7793: Evidence for Stellar Radial Migration
• The ACS LCID project. IX. Imprints of the early Universe in the radial variation of the star formation history of dwarf galaxies
• Fitting Analysis using Differential Evolution Optimization (FADO): Spectral population synthesis through genetic optimization under self-consistency boundary conditions
• The Structure and Stellar Content of the Outer Disks of Galaxies: A New View from the Pan-STARRS1 Medium Deep Survey
• Outer-disk reddening and gas-phase metallicities: The CALIFA connection
• Stellar Populations and Radial Migrations in Virgo Disk Galaxies
• No direct coupling between bending of galaxy disc stellar age and light profiles
• Quantifying radial migration in the Milky Way: Inefficient over short timescales but essential to the very outer disc beyond ~15 kpc
• Galaxy gas flows inferred from a detailed, spatially resolved metal budget
• PPAK Wide field Integral Field Spectroscopy of NGC 628 III. Stellar population properties
• Dissecting galactic bulges in space and time I: the importance of early formation scenarios vs. secular evolution
• Dust emission profiles of DustPedia galaxies
• The ACS Nearby Galaxy Survey Treasury XI. The Remarkably Undisturbed NGC 2403 Disk
• The BaLROG project - II. Quantifying the influence of bars on the stellar populations of nearby galaxies
• Stellar haloes outshine disc truncations in low-inclined spirals
• Influence of galaxy stellar mass and observed wavelength on disc breaks in S${}^4$G, NIRS0S, and SDSS data
• Observational hints for radial migration in disc galaxies from CALIFA
• The imprint of satellite accretion on the chemical and dynamical properties of disc galaxies
• Exponential Disks from Stellar Scattering: III. Stochastic Models
• Mass Metallicity Relationship of SDSS Star Forming Galaxies: Population Synthesis Analysis and Effects of Star Burst Length, Extinction Law, Initial Mass Function and Star Formation Rate
• The Role of Stellar Radial Motions in Shaping Galaxy Surface Brightness Profiles
• Exponential profiles from stellar scattering off interstellar clumps and holes in dwarf galaxy discs
• Star Formation in Two Luminous Spiral Galaxies
• The Gaia-ESO Survey: Separating disk chemical substructures with cluster models
• The Impact of Stellar Migration on Disk Outskirts
• New Constraints on the Origin of Surface Brightness Profile Breaks of Disk Galaxies from MaNGA
• CLUES about M33: the reversed radial stellar age gradient in the outskirts of Triangulum galaxy
• Outskirts of Nearby Disk Galaxies: Star Formation and Stellar Populations
• The Isophotal Structure of Star-forming Galaxies at $0.5<z<1.8$ in CANDELS: Implications for the Evolution of Galaxy Structure
• A study of outer disk stellar populations of face-on star-forming galaxies in SDSS-IV MaNGA: causes of H$\alpha$ deficiency
• Exploring the outskirts of the EAGLE disc galaxies
• The Mitchell Spectrograph: Studying Nearby Galaxies with the VIRUS Prototype
• Comparing radial migration in dark matter and MOND regimes
• Size-Mass Relation Shows Its Colours: Contrasting Physical Imprints of Galaxy Evolution in Rest-Frame UV and Optical