The 3.3 μm Polycyclic Aromatic Hydrocarbon Emission as a Star Formation Rate Indicator
Abstract
Polycyclic aromatic hydrocarbon (PAH) emission features dominate the mid-infrared spectra of star-forming galaxies and can be useful to calibrate star formation rates (SFRs) and diagnose ionized states of grains. However, the PAH 3.3 μm feature has not been studied as much as other PAH features since it is weaker than others and resides outside of Spitzer capability. In order to detect and calibrate the 3.3 μm PAH emission and investigate its potential as an SFR indicator, we carried out an AKARI mission program, AKARI mJy Unbiased Survey of Extragalactic Sources (AMUSES), and compared its sample with various literature samples. We obtained 2-5 μm low-resolution spectra of 20 flux-limited galaxies with mixed spectral energy distribution classes, which yielded the detection of the 3.3 μm PAH emission from 3 out of 20 galaxies. For the combined sample of AMUSES and literature samples, the 3.3 μm PAH luminosities correlate with the infrared luminosities of star-forming galaxies, albeit with a large scatter (1.5 dex). The correlation appears to break down at the domain of ultraluminous infrared galaxies (ULIRGs), and the power of the 3.3 μm PAH luminosity as a proxy for the infrared luminosity is hampered at log[L P_(AH3.3) erg^(–1) s^(–1)] > ~42.0. Possible origins for this deviation in the correlation are discussed, including contributions from active galactic nuclei and strongly obscured young stellar objects, and the destruction of PAH molecules in ULIRGs.
Additional Information
© 2012 American Astronomical Society. Received 2011 December 8; accepted 2012 September 29; published 2012 November 15. The authors sincerely appreciate the anonymous referee's helpful comments and suggestions to improve the quality of this paper. They also thank Yanling Wu for her work leading to this paper. This work was supported by a Korean Research Foundation (KRF) grant funded by the Korean government (MEST), No. 2010–0000712. This research is based on observations with AKARI, a JAXA project with the participation of ESA.Attached Files
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Additional details
- Eprint ID
- 36060
- Resolver ID
- CaltechAUTHORS:20121219-145701379
- National Research Foundation of Korea
- 2010-0000712
- Ministry of Education, Science and Technology (Korea)
- Created
-
2012-12-19Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)