Visit ASIAA Homepage Registration Deadline: November 1, 2018 (Taiwan Time)
East-Asia AGN Workshop 2019
January 21(Mon)-23(Wed), 2019
ASIAA Auditorium, 1st Floor AS/NTU Astronomy-Mathematics Building

Poster Presentation

A New Method to Measure Star Formation Rates in Active Galaxies Using Mid-IR Neon Lines

Author(s): Ming-Yang Zhuang (KIAA; PKU) Luis C. Ho (KIAA; PKU)

Presenter: Mingyang Zhuang (KIAA at Peking University)

The star formation rate (SFR) is one of the most fundamental parameters of galaxies, but nearly all of the standard SFR diagnostics are difficult to measure in active galaxies because of contamination from the active galactic nucleus (AGN). Suffering from less extinction, the mid-IR fine-structure lines of [Ne II] 12.81 μm and [Ne III] 15.56 μm have the potential to disentangle the AGN contribution and yield a reliable SFR indicator, provided that their contribution from the AGN narrow-line region can be subtracted. In this paper, we use photoionization calculations with realistic AGN spectral energy distributions and input assumptions to constrain the magnitude of [Ne II] and [Ne III] produced by the narrow-line region for a given strength of [Ne V] 14.32 μm. We demonstrate that AGNs emit a relatively restricted range of [Ne II]/[Ne V] and [Ne III]/[Ne V] ratios. Hence, once [Ne V] is measured, the AGN contribution to the low-ionization Ne lines can be estimated and the SFR can be determined from the strength of [Ne II] and [Ne III]. We use this new technique to estimate the SFRs of AGN host galaxies and compare them to samples of star-forming galaxies, using mid-IR spectra observed with Spitzer.

ASIAA will not contact participants for credit card information. Privacy and Security Policy