A spectroscopic study of blue supergiant stars in the Sculptor galaxy NGC 55: chemical evolution and distance

Abstract

Low resolution (4.5 to 5 Angstroem) spectra of 58 blue supergiant stars distributed over the disk of the Magellanic spiral galaxy NGC 55 in the Sculptor group are analyzed by means of non-LTE techniques to determine stellar temperatures, gravities and metallicities (from iron peak and alpha-elements). A metallicity gradient of -0.22 +/- 0.06$ dex/R_25 is detected. The central metallicity on a logarithmic scale relative to the Sun is [Z] = -0.37 +\- 0.03. A chemical evolution model using the observed distribution of stellar and interstellar medium gas mass column densities reproduces the observed metallicity distribution well and reveals a recent history of strong galactic mass accretion and wind outflows with accretion and mass-loss rates of the order of the star formation rate. There is an indication of spatial inhomogeneity in metallicity. In addition, the relatively high central metallicity of the disk confirms that two extra-planar metal poor HII regions detected in previous work 1.13 to 2.22 kpc above the galactic plane are ionized by massive stars formed in-situ outside the disk. For a sub-sample of supergiants, for which Hubble Space Telescope photometry is available, the flux-weighted gravity--luminosity relationship is used to determine a distance modulus of 26.85 +\- 0.10 mag.

Accepted by ApJ, 29 pages, 13 figures, 4 tables

References in corpus (15)

• The ACS Nearby Galaxy Survey Treasury
• The Universal Relation of Galactic Chemical Evolution: The Origin of the Mass-Metallicity Relation
• Extragalactic chemical abundances: do HII regions and young stars tell the same story? The case of the spiral galaxy NGC 300
• A Turnover in the Galaxy Main Sequence of Star Formation at $M_{\ast }\sim 10^{10}{M}_{\odot }$ for Redshifts $z<1.3$
• The Abundance Properties of Nearby Late-Type Galaxies.I. The Data
• Quantitative Spectroscopy of 24 A supergiants in the Sculptor galaxy NGC 300: Flux weighted gravity luminosity relationship, metallicity and metallicity gradient
• The spectroscopic Hertzsprung-Russell diagram
• The Araucaria Project: the Local Group Galaxy WLM--Distance and metallicity from quantitative spectroscopy of blue Supergiants
• The chemical evolution of local star forming galaxies: Radial profiles of ISM metallicity, gas mass, and stellar mass and constraints on galactic accretion and winds
• Red Supergiants as Cosmic Abundance Probes: The Sculptor Galaxy NGC 300
• Stellar Metallicity of the Extended Disk and Distance of the Spiral Galaxy NGC 3621
• Quantitative spectroscopy of Galactic BA-type supergiants. I. Atmospheric parameters
• The Araucaria Project: VLT-spectroscopy of blue massive stars in NGC 55
• The Araucaria Project. Near-Infrared Photometry of Cepheid Variables in the Sculptor Galaxy NGC 55
• The Araucaria Project. The Distance to the Sculptor Group Galaxy NGC 55 from a Newly Discovered Abundant Cepheid Population

Cited by in corpus (31)

• The Mass-Metallicity and the Fundamental Metallicity Relation revisited on a fully Te-based abundance scale for galaxies
• Stellar Absorption Line Analysis of Local Star-Forming Galaxies: The Relation Between Stellar Mass, Metallicity, Dust Attenuation and Star Formation Rate
• Stellar labels for hot stars from low-resolution spectra - I. the HotPayne method and results for 330,000 stars from LAMOST DR6
• The Chemical Evolution Carousel of Spiral Galaxies: Azimuthal Variations of Oxygen Abundance in NGC1365
• A Catalogue of OB Stars from LAMOST Spectroscopic Survey
• A Characteristic Mass Scale in the Mass-Metallicity Relation of Galaxies
• L-GALAXIES 2020: The evolution of radial metallicity profiles and global metallicities in disc galaxies
• Red Supergiants as Cosmic Abundance Probes: massive star clusters in M83, and the mass-metallicity relation of nearby galaxies
• The stellar mass versus stellar metallicity relation of star-forming galaxies at $1.6\le z\le 3.0$ and implications for the evolution of the $\alpha$-enhancement
• The mass-metallicity relation at z~1-2 and its dependence on star formation rate
• Observational properties of massive black hole binary progenitors
• The metallicity and distance of NGC 2403 from blue supergiants
• The First Metallicity Study of M83 using the integrated UV light of Star Clusters
• Quantitative spectroscopy of B-type supergiants
• A spectroscopic study of blue supergiant stars in Local Group spiral galaxies: Andromeda and Triangulum
• Galaxy Lookback Evolution Models -- a Comparison with Magneticum Cosmological Simulations and Observations
• 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
• Gas-phase Fe/O and Fe/N abundances in Star-Forming Regions. Relations between nucleosynthesis, metallicity and dust
• Metallicities of Young Massive Clusters in NGC 5236 (M83)
• Trading oxygen for iron I: the [O/Fe] -- specific star formation rate relation of galaxies
• SDSS-IV MaNGA: The MaNGA Dwarf Galaxy Sample
• Extraplanar HII Regions in the edge-on Spiral Galaxies NGC 3628 and NGC 4522
• Modified Gravity and the Flux-weighted Gravity-Luminosity Relationship of Blue Supergiant Stars
• A Simple Unified Spectroscopic Indicator of Stellar Luminosity: the Extended Flux Weighted Gravity-Luminosity Relationship
• Spectral energy distributions of classical cepheids in the Magellanic Clouds
• The flux-weighted gravity-luminosity relation of Galactic classical Cepheids
• pop-cosmos: Insights from generative modeling of a deep, infrared-selected galaxy population
• Runaway BN supergiant star HD 93840: Progenitor of an imminent core-collapse supernova above the Galactic plane
• MUSE crowded field 3D spectroscopy in NGC 300 II. Quantitative spectroscopy of BA-type supergiants
• HR-pyPopStar II: high spectral resolution evolutionary synthesis models low metallicity expansion and the properties of the stellar populations of dwarf galaxies
• Extra-galactic distances with massive stars: the role of stellar variability in the case of M33