2002/08/31 by L. J. Kewley, Lisa J. Kewley, Margaret J. Geller +4 · 8 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Balmer series #Emission spectrum #Extinction (optical mineralogy) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Infrared #Luminous infrared galaxy #Optics #Physics #Spectral line #Star formation #Stellar population #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/344487
published as Astron.J.124:3135,2002 · 23 pages, 5 figures, 1 table. Accepted for publication in the Astronomical Journal. V2: Important changes: IRAS fluxes updated. Only moderate and good quality IRAS FIR fluxes are now used, resulting in slight changes to the equations and figures. The IR and H-alpha SFRs now agree to within ~10%, rather than ~30% as quoted previously
arxiv created 2002/09/14 · openalex publication_date 2002/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We investigate the Hα and infrared star formation rate (SFR) diagnostics for galaxies in the Nearby Field Galaxy Survey (NFGS). For the 81 galaxies in our sample, we derive Hα fluxes (included here) from integrated spectra. There is a strong correlation between the ratio of far-infrared to optical luminosities L (FIR)/ L (Hα) and the extinction E ( B - V ) measured with the Balmer decrement. Before reddening correction, the SFR(IR) and SFR(Hα) are related to each other by a power law: SFR(IR) = (2.7 ± 0.3)SFR(Hα) 1.30±0.06 . Correction of the SFR(Hα) for extinction using the Balmer decrement and a classical reddening curve both reduces the scatter in the SFR(IR)-SFR(Hα) correlation and results in a much closer agreement between the two SFR indicators; SFR(IR) = (0.91 ± 0.04)SFR(Hα corr ) 1.07±0.03 . SFR(IR) and SFR(Hα) agree to ∼10%. This SFR relationship spans 4 orders of magnitude and holds for all Hubble types with IRAS detections in the NFGS. A constant ratio between the SFR(IR) and SFR(Hα) for all Hubble types, including early types (S0–Sab), suggests that the IR emission in all these objects results from a young stellar population.