TY - JOUR
T1 - The SAMI Galaxy Survey
T2 - Spatially resolved metallicity and ionization mapping
AU - Poetrodjojo, Henry
AU - Groves, Brent
AU - Kewley, Lisa J.
AU - Medling, Anne M.
AU - Sweet, Sarah M.
AU - van de Sande, Jess
AU - Sanchez, Sebastian F.
AU - Bland-Hawthorn, Joss
AU - Brough, Sarah
AU - Bryant, Julia J.
AU - Cortese, Luca
AU - Croom, Scott M.
AU - López-Sánchez, Ángel R.
AU - Richards, Samuel N.
AU - Zafar, Tayyaba
AU - Lawrence, Jon S.
AU - Lorente, Nuria P. F.
AU - Owers, Matt S.
AU - Scott, Nicholas
PY - 2018/10/1
Y1 - 2018/10/1
N2 - We present gas-phase metallicity and ionization parameter maps of 25 star-forming face-on spiral galaxies from the SAMI Galaxy Survey Data Release 1. Self-consistent metallicity and ionization parameter maps are calculated simultaneously through an iterative process to account for the interdependence of the strong emission line diagnostics involving ([O II]+[O III])/Hβ (R23) and [O III]/[O II](O32). The maps are created on a spaxel-by-spaxel basis because H II regions are not resolved at the SAMI spatial resolution. We combine the SAMI data with stellar mass, star formation rate (SFR), effective radius (Re), ellipticity, and position angles (PA) from the GAMA survey to analyse their relation to the metallicity and ionization parameter. We find a weak trend of steepening metallicity gradient with galaxy stellar mass, with values ranging from −0.03 to −0.20 dex/Re. Only two galaxies show radial gradients in the ionization parameter. We find that the ionization parameter has no significant correlation with either SFR, sSFR (specific SFR), or metallicity. For several individual galaxies, we find the structure in the ionization parameter maps suggestive of spiral arm features. We find a typical ionization parameter range of 7.0 < log (q) < 7.8 for our galaxy sample with no significant overall structure. An ionization parameter range of this magnitude is large enough to caution the use of metallicity diagnostics that have not considered the effects of a varying ionization parameter distribution.
AB - We present gas-phase metallicity and ionization parameter maps of 25 star-forming face-on spiral galaxies from the SAMI Galaxy Survey Data Release 1. Self-consistent metallicity and ionization parameter maps are calculated simultaneously through an iterative process to account for the interdependence of the strong emission line diagnostics involving ([O II]+[O III])/Hβ (R23) and [O III]/[O II](O32). The maps are created on a spaxel-by-spaxel basis because H II regions are not resolved at the SAMI spatial resolution. We combine the SAMI data with stellar mass, star formation rate (SFR), effective radius (Re), ellipticity, and position angles (PA) from the GAMA survey to analyse their relation to the metallicity and ionization parameter. We find a weak trend of steepening metallicity gradient with galaxy stellar mass, with values ranging from −0.03 to −0.20 dex/Re. Only two galaxies show radial gradients in the ionization parameter. We find that the ionization parameter has no significant correlation with either SFR, sSFR (specific SFR), or metallicity. For several individual galaxies, we find the structure in the ionization parameter maps suggestive of spiral arm features. We find a typical ionization parameter range of 7.0 < log (q) < 7.8 for our galaxy sample with no significant overall structure. An ionization parameter range of this magnitude is large enough to caution the use of metallicity diagnostics that have not considered the effects of a varying ionization parameter distribution.
KW - galaxies: abundances
KW - galaxies: ISM
UR - http://www.scopus.com/inward/record.url?scp=85051496753&partnerID=8YFLogxK
U2 - 10.1093/mnras/sty1782
DO - 10.1093/mnras/sty1782
M3 - Article
VL - 479
SP - 5235
EP - 5265
JO - Monthly Notices of the Royal Astronomical Society: Letters
JF - Monthly Notices of the Royal Astronomical Society: Letters
SN - 1745-3925
IS - 4
ER -