[FeII] as a tracer of supernova rate in nearby starburst galaxies

Abstract

Context. Supernovae play an integral role in the feedback of processed material into the ISM of galaxies making them responsible for much of the chemical enrichment of the universe. The rate of supernovae can also reveal star formation histories. These rates are usually measured through the nonthermal radio continuum luminosity; however, a correlation between near-infrared [FeII] emission and supernova remnants has also been noted. Aims. We aim to find a quantitative relationship between the [FeII] at 1.26 μm ([FeII] 1.26 ) luminosity and the supernova rate in a sample of 11 nearby starburst galaxy centers. Methods. We performed a pixel-pixel analysis of this correlation on SINFONI data cubes. Using Brγ equivalent width and luminosity as the only observational inputs into the Starburst 99 model, we derived the supernova rate at each pixel and have thus created maps of supernova rates. We then compared these morphologically and quantitatively to the [FeII] 1.26 luminosity. Results. We have found that a strong linear and morphological correlation exists between supernova rate and [FeII] 1.26 on a pixel-topixel basis. This relation is valid for normal star-forming galaxies but breaks down for extreme ultraluminous galaxies. Conclusions. The supernova rates derived from the Starburst 99 model are in good agreement with the radio derived supernova rates, which underlines the strength of using [FeII] emission as a tracer of supernova rate. With the strong correlation found in this sample of galaxies, we conclude that [FeII] 1.26 emission can generally be used to derive accurate supernova rates on either a pixel-pixel or integrated galactic basis.

Alma Observations of Warm Dense Gas in NGC 1614—breaking of the Star Formation Law in the Central Kiloparsec

“…The dustattenuated Pa-α emission map was obtained from the F190N narrow-band line+continuum image after the subtraction of the adjacent continuum emission obtained with the F187N filter. In order to correct the Pa-α map for the significant extinction (e.g., Neff et al 1990;Alonso-Herrero et al 2001;Kotilainen et al 2001;Rosenberg et al 2012), we used the EW map of the emission line plus two broadband NIR continuum images obtained at 1.6 and 2.2 um.…”

Nonthermal particles and photons in starburst regions and superbubbles

“…The authors suggested that the [Fe II] lines may be produced by an SNR population of ages up 10 4 years, while radio SNRs are a younger population of a few hundred years old. Rosenberg et al (2012) found a nearly linear relationship between the 1.26 µm [Fe II] luminosity and the supernova rate in a sample of 11 nearby starburst galaxy centers. This relationship is valid for normal SF galaxies but does not hold for extreme ultraluminous galaxies.…”

ALMA-backed NIR high resolution integral field spectroscopy of the NUGA galaxy NGC 1433

“…If the central Brγ excitation is assumed to be originating from stars only, i.e., no excitation by AGN radiation, the luminosity of Brγ in this region can be used to determine a star formation rate (SFR; Panuzzo et al 2003;Valencia-S. et al 2012). We derive an upper limit for the SFR within a 1 radius around the nucleus of 1.4 × 10 Rosenberg et al 2012;Esquej et al 2014, and references therein) compared to other non-starburst galaxies, particularly with regard to the assumption that all of the central Brγ and [Fe ] emission is attributed to star formation, which is an unlikely scenario in a Seyfert like galaxy.…”