The building up of the disk galaxy M33 and the evolution of the metallicity gradient

Abstract

The evolution of radial gradients of metallicity in disk galaxies and its relation with the disk formation are not well understood. Theoretical models of galactic chemical evolution make contrasting predictions about the time evolution of metallicity gradients. To test chemical evolution models and trace the star formation and accretion history of low luminosity disk galaxies we focus on the Local Group galaxy M33. We analyze O/H and S/H abundances in planetary nebulae, H{\sc ii} regions, and young stars, together with known [Fe/H] abundances in the old stellar population of M33. With a theoretical model, we follow the time evolution of gas (diffuse and condensed in clouds), stars, and chemical abundances in the disk of M33, assuming that the galaxy is accreting gas from an external reservoir. Our model is able to reproduce the available observational constraints on the distribution of gas and stars in M33 and to predict the time evolution of several chemical abundances. In particular, we find that a model characterized by a continuous infall of gas on the disk, at a rate of ${\dot{M}}_{\inf }\approx 1$ $M_{\odot }$ yr${}^{-1}$, almost constant with time, can also account for the relatively high rate of star formation and for the shallow chemical gradients. Supported by a large sample of high resolution observations for this nearby galaxy, we conclude that the metallicity in the disk of M33 has increased with time at all radii, with a continuous flattening of the gradient over the last $\sim 8$ Gyr.

16 pages, 11 figures, A&A accepted

References in corpus (5)

• Planetary Nebula Abundances and Morphology: Probing the Chemical Evolution of the Milky Way
• The stellar halo and outer disk of M33
• New results on the time variation of the radial abundance gradients from planetary nebulae
• Detection of Beat Cepheids in M33 and Their Use as a Probe of the M33 Metallicity Distribution
• Rotating massive stars: Pre-SN models and stellar yields at solar metallicity

Cited by in corpus (27)

• Star formation sustained by gas accretion
• The evolution of the Galactic metallicity gradient from high-resolution spectroscopy of open clusters
• Star formation in M33: multiwavelength signatures across the disk
• Enhanced production of barium in low-mass stars: evidence from open clusters
• Planetary Nebulae in Face-On Spiral Galaxies. I. Planetary Nebula Photometry and Distances
• Dynamical signatures of a LCDM-halo and the distribution of the baryons in M33
• The Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER) I. Ultraviolet to Infrared Photometry of 22 Million Stars in M33
• The Grism Lens-Amplified Survey from Space (GLASS). II. Gas-phase metallicity and radial gradients in an interacting system at z~2
• HST/COS Observations of Ionized Gas Accretion at the Disk-halo Interface of M33
• AGB stars as tracers of metallicity and mean age across M33
• The UK Infrared Telescope M33 monitoring project. V. The star formation history across the galactic disc
• HI clouds in the proximity of M33
• Bar imprints on the inner gas kinematics of M33
• The cluster birthline in M33
• Magnetic-buoyancy-induced mixing in AGB Stars: a theoretical explanation of the non-universal [Y/Mg]-age relation
• The radial metallicity gradient and the history of elemental enrichment in M81 through emission-line probes
• Star Formation Histories of the LEGUS Spiral Galaxies. I. The flocculent spiral NGC 7793
• Triangulum galaxy viewed by Planck
• The dark matter halo density profile, spiral arm morphology and black hole mass of M33
• Keck spectroscopy and Spitzer Space Telescope analysis of the outer disk of the Triangulum Spiral Galaxy M33
• Dust Extinction Law in Nearby Star-Resolved Galaxies. II. M33 Traced by Supergiants
• The color gradients of spiral disks in the Sloan Digital Sky Survey
• Rise and fall of molecular clouds across the M33 disk
• The Origin of Star Formation in Early-type Galaxies Inferred from Spatially Resolved Spectroscopy
• Probing the origins. I. Generalised Additive Model inference of birth radii for Milky Way stars in the solar vicinity
• A comparative study of O, Ne, Cl, and Ar in Hii regions and PNe of the Galactic disk: Temporal evolution of radial gradients?
• The IRAM M33 CO(2-1) Survey - A complete census of the molecular gas out to 7 kpc