A Comparison of Star Formation Rates by Different Tracers in Nearby Galaxies

Abstract We utilize a large sample of ∼113,000 galaxies ( z &lt; 0.3) from the Sloan Digital Sky Survey with high-quality data to compare star formation rates (SFRs) across multiple diagnostic methods and examine their connection to the strength of active galactic nuclei (AGNs), indicated by Eddington ratio. Our sample encompassed star-forming, composite, Seyfert, and LINER galaxies. Our analysis utilizes various SFR indicators, including observed infrared flux (SFR FIR ) from AKARI/Herschel (∼4100 sources), the MPA-JHU catalog ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>SFR</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">D</mml:mi> <mml:mi>n</mml:mi> <mml:mn>4000</mml:mn> </mml:mrow> </mml:msub> </mml:math> ), the artificial neural network​​​​​​ (ANN) catalog (SFR ANN ), the GSWLC catalog (SFR SED and SFR MIR ), as well as [O ii ] and H α emission lines (SFR [O II] and SFR H α ). Within star-forming galaxies, SFR measurements from different tracers exhibited differences, with offsets and scatter below 0.26 and 0.29 dex, respectively. Moreover, non-star-forming galaxies (composite, Seyfert, and LINER) displayed discrepancies among SFR tracers, particularly for LINER galaxies, with offsets below 0.86 dex and a scatter of 0.57 dex. Additionally, our findings revealed robust correlations between SFRs and specific SFRs (sSFRs) with Eddington ratios. The Eddington ratio exhibited gradual transitions in the (s)SFRs–stellar mass diagrams. Galaxies with high Eddington ratios displayed high star formation activity, similar to blue star-forming galaxies. Furthermore, we observed decreasing sSFR trends from star-forming galaxies to composite, Seyfert, and LINER galaxies. Our results may provide insight into our understanding of (s)SFRs traced by different approaches and their connection to AGN activities.