| Full text | |
| Author(s): |
Vale Asari, N.
[1, 2]
;
Couto, G. S.
[2, 3]
;
Cid Fernandes, R.
[2]
;
Stasinska, G.
[4]
;
de Amorim, A. L.
[2]
;
Ruschel-Dutra, D.
[2]
;
Werle, A.
[2, 5]
;
Florido, T. Z.
[2]
Total Authors: 8
|
| Affiliation: | [1] Univ St Andrews, Sch Phys & Astron, St Andrews KY16 9SS, Fife - Scotland
[2] Univ Fed Santa Catarina, CFM, Dept Fis, BR-88040900 Florianopolis, SC - Brazil
[3] Univ Antofagasta, Ctr Astron CITEVA, Ave Angamos 601, Antofagasta 02800 - Chile
[4] PSL Univ, Observ Paris, CNRS, LUTH, F-92195 Paris - France
[5] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, R Matao 1226, BR-05508090 Sao Paulo - Brazil
Total Affiliations: 5
|
| Document type: | Journal article |
| Source: | Monthly Notices of the Royal Astronomical Society; v. 489, n. 4, p. 4721-4733, NOV 2019. |
| Web of Science Citations: | 0 |
| Abstract | |
We investigate the impact of the diffuse ionized gas (DIG) on abundance determinations in star-forming (SF) galaxies. The DIG is characterized using the H alpha equivalent width (W-H alpha). From a set of 1 409 SF galaxies from the Mapping Nearby Galaxies at APO (MaNGA) survey, we calculate the fractional contribution of the DIG to several emission lines using high-S/N data from SF spaxels (instead of using noisy emission-lines in DIG-dominated spaxels). Our method is applicable to spectra with observed W-H alpha greater than or similar to 10 angstrom (which are not dominated by DIG emission). Since the DIG contribution depends on galactocentric distance, we provide DIG-correction formulae for both entire galaxies and single aperture spectra. Applying those to a sample of > 90 000 SF galaxies from the Sloan Digital Sky Survey, we find the following. (1) The effect of the DIG on strong-line abundances depends on the index used. It is negligible for the ({[}O III]/H ss)/({[}N II]/H alpha) index, but reaches similar to 0.1 dex at the high-metallicity end for {[}N II]/H alpha. (2) This result is based on the similar to kpc MaNGA resolution, so the real effect of the DIG is likely greater. (3) We revisit the mass-metallicity-star formation rate (SFR) relation by correcting for the DIG contribution in both abundances and SFR. The effect of DIG removal is more prominent at higher stellar masses. Using the {[}N II]/H alpha index, O/H increases with SFR at high stellar mass, contrary to previous claims. (AU) | |
| FAPESP's process: | 19/01768-6 - Large-scale structure in the local universe with the S-PLUS survey |
| Grantee: | Ariel Werle |
| Support Opportunities: | Scholarships in Brazil - Technical Training Program - Technical Training |