Journal article
SDSS IV MaNGA: Metallicity and ionisation parameter in local star-forming galaxies from Bayesian fitting to photoionisation models
Astronomy and astrophysics (Berlin), Vol.636, p.A42
04/01/2020
DOI: 10.1051/0004-6361/201937203
Abstract
We measured gas-phase metallicity, ionisation parameter, and dust extinction for a representative sample of 1795 local star-forming galaxies using integral field spectroscopy from the SDSS-IV MaNGA survey. We self-consistently derive these quantities by comparing observed line fluxes with photoionisation models using a Bayesian framework. We also present the first comprehensive study of the [SIII]lambda lambda 9069,9532 nebular lines, which have long been predicted to be ideal tracers of the ionisation parameter. However, we find that current photoionisation model predictions substantially over-predict the intensity of the [SIII] lines, while broadly reproducing other observed optical line ratios. We discuss how to nonetheless make use of the information provided by the [SIII] lines by setting a prior on the ionisation parameter. Following this approach, we derive spatially resolved maps and radial profiles of metallicity and ionisation parameter. The metallicity radial profiles derived are comparable with previous works, with metallicity declining toward the outer parts and showing a flattening in the central regions. This is in agreement with infall models of galaxy formation, which predict that spiral discs build up through accretion of material, leading to an inside-out growth. On the other hand, ionisation parameter radial profiles are flat for low-mass galaxies, while their slope becomes positive as galaxy mass increases. However, the ionisation parameter maps we obtain are clumpy, especially for low-mass galaxies. The ionisation parameter is tightly correlated with the equivalent width of H alpha [EW(H alpha)], following a nearly universal relation, which we attribute to the change of the spectral shape of ionising sources due to ageing of HII regions. We derive a positive correlation between ionisation parameter and metallicity at fixed EW(H alpha), in disagreement with previous theoretical work that predict an anti-correlation.
Details
- Title: Subtitle
- SDSS IV MaNGA: Metallicity and ionisation parameter in local star-forming galaxies from Bayesian fitting to photoionisation models
- Creators
- M. Mingozzi - University of BolognaF. Belfiore - European Southern ObservatoryG. Cresci - Arcetri Astrophysical ObservatoryK. Bundy - University of California, Santa CruzM. Bershady - University of Wisconsin–MadisonD. Bizyaev - New Mexico State UniversityG. Blanc - University of ChileM. Boquien - University of AntofagastaN. Drory - The University of Texas at AustinH. Fu - University of IowaR. Maiolino - University of CambridgeR. Riffel - Laboratório Interinstitucional de e-AstronomiaA. Schaefer - University of Wisconsin–MadisonT. Storchi-Bergmann - Laboratório Interinstitucional de e-AstronomiaE. Telles - Valongo ObservatoryC. Tremonti - University of Wisconsin–MadisonN. Zakamska - Johns Hopkins UniversityK. Zhang - Lawrence Berkeley National Laboratory
- Resource Type
- Journal article
- Publication Details
- Astronomy and astrophysics (Berlin), Vol.636, p.A42
- Publisher
- Edp Sciences S A
- DOI
- 10.1051/0004-6361/201937203
- ISSN
- 0004-6361
- eISSN
- 1432-0746
- Number of pages
- 26
- Grant note
- University of Notre Dame New York University Universidad Nacional Autonoma de Mexico Max-PlanckInstitut fur Extraterrestrische Physik (MPE) University of Utah Harvard-Smithsonian Center for Astrophysics; Smithsonian Institution Lawrence Berkeley National Laboratory; United States Department of Energy (DOE) Ohio State University Vanderbilt University Center for High-Performance Computing at the University of Utah Max-Planck-Institut fur Astronomie (MPIA Heidelberg) Carnegie Institution for Science National Astronomical Observatories of China Chilean Participation Group U.S. Department of Energy Office of Science; United States Department of Energy (DOE) Alfred P. Sloan Foundation Carnegie Mellon University Max-Planck-Institut fur Astrophysik (MPA Garching) United Kingdom Participation Group University of Washington 1170618 / FONDECYT; Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT); CONICYT FONDECYT Instituto de Astrofisica de Canarias University of Wisconsin Observatorio Nacional/MCTI University of Arizona Yale University New Mexico State University Pennsylvania State University University of Oxford University of Portsmouth Kavli Institute for the Physics and Mathematics of the Universe (IPMU)/University of Tokyo 1.05.01.88.04 / INAF PRINSKA 2017 programme Brazilian Participation Group 695671 / ERC; European Research Council (ERC); European Commission French Participation Group University of Colorado Boulder University of Virginia ST/M001172/1 / STFC; UK Research & Innovation (UKRI); Science & Technology Facilities Council (STFC) AST-1554877 / NSF CAREER Award; National Science Foundation (NSF); NSF - Office of the Director (OD) Leibniz Institut fur Astrophysik Potsdam (AIP) Science and Technology Facilities Council (STFC); UK Research & Innovation (UKRI); Science & Technology Facilities Council (STFC); Science and Technology Development Fund (STDF) Shanghai Astronomical Observatory Korean Participation Group Johns Hopkins University
- Language
- English
- Date published
- 04/01/2020
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984429056202771
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