Calibration-based abundances in the interstellar gas of galaxies from slit and IFU spectra

¹ Institute of Theoretical Physics and Astronomy, Vilnius University, Sauletekio av. 3, 10257 Vilnius, Lithuania
e-mail: pil620a@gmail.com
² Main Astronomical Observatory, National Academy of Sciences of Ukraine, 27 Akademika Zabolotnoho St, 03680 Kiev, Ukraine
³ Departamento de Física de la Tierra y Astrofísica, Universidad Complutense de Madrid, 28040 Madrid, Spain
⁴ Instituto de Física de Partículas y del Cosmos IPARCOS, Fac. de Ciencias Físicas, Univ. Complutense de Madrid, 28040 Madrid, Spain
⁵ Instituto de Astrofísica de Andalucía, CSIC, Apdo 3004, 18080 Granada, Spain
⁶ Département de Physique, de Génie Physique et d’Optique, Université Laval, et Centre de Recherche en Astrophysique du Québec (CRAQ), Québec, QC G1V 0A6, Canada
⁷ Faculty of Physics, Ludwig-Maximilians-Universität, Scheinerstr. 1, 81679 Munich, Germany
⁸ Universidade do Vale do Paraíba, Av. Shishima Hifumi, 2911, 12244-000 São José dos Campos, SP, Brazil

Received: 9 June 2022
Accepted: 27 September 2022

Abstract

In this work, we make use of available integral field unit (IFU) spectroscopy and slit spectra of several nearby galaxies. The pre-existing empirical R and S calibrations for abundance determinations are constructed using a sample of H II regions with high-quality slit spectra. In this paper, we test the applicability of those calibrations to the IFU spectra. We estimate the calibration-based abundances obtained using both the IFU and the slit spectroscopy for eight nearby galaxies. The median values of the slit and IFU spectra-based abundances in bins of 0.1 in fractional radius R_g (normalised to the optical radius R₂₅) of a galaxy are determined and compared. We find that the IFU and the slit spectra-based abundances obtained through the R calibration are close to each other; the mean value of the differences of abundances is 0.005 dex, and the scatter in the differences is 0.037 dex for 38 datapoints. The S calibration can produce systematically underestimated values of the IFU spectra-based abundances at high metallicities (12 + log(O/H) ≳8.55); the mean value of the differences is −0.059 dex for 21 datapoints, while at lower metallicities the mean value of the differences is −0.018 dex and the scatter is 0.045 dex for 36 data points. This provides evidence that the R calibration produces more consistent abundance estimations between the slit and the IFU spectra than the S calibration. We find that the same calibration can produce close estimations of the abundances using IFU spectra obtained with different spatial resolution and different spatial samplings. This is in line with the recent finding that the contribution of the diffuse ionised gas to the large-aperture spectra of H II regions has a secondary effect.