PAH emission from the dust lane of an elliptical galaxy with the Spitzer IRS

Abstract

Spitzer and AKARI observations have found that polycyclic aromatic hydrocarbons (PAHs) are present in nearby elliptical galaxies, but their spatial distributions are still unknown. In order to investigate their distributions, we performed deep spectral mapping observations of the PAH-detected elliptical galaxy NGC4589, a merger remnant with a minor-axis optical dust lane. As a result, we obtain clear evidence that the PAH 11.3 um emission comes predominantly from the dust lane of the galaxy. We also detect molecular hydrogen line emissions from the dust lane. The PAH 17 um emission is distributed differently from the PAH 11.3 um emission, and more similarly to the dust continuum emission. From their distinctive distributions, we suggest that the PAHs responsible for the 11.3 um feature are secondary products through the evolution of the ISM brought in by the merger.

5 pages, 4 figures, accepted for publication in the ApJL

References in corpus (3)

• Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
• Properties of polycyclic aromatic hydrocarbons in local elliptical galaxies revealed by the Infrared Spectrograph on Spitzer
• Early-type galaxies with core collapse supernovae

Cited by in corpus (5)

• The dustier early-type galaxies deviate from late-type galaxies' scaling relations
• Dust and Ionized Gas Association in E/S0 Galaxies with Dust Lanes: Clues to their Origin
• Properties of dust and PAHs in the hot plasma of the elliptical galaxy NGC4125 revealed with AKARI and Spitzer
• Star Clusters in the Elliptical Galaxy NGC 4589 Hosting a Calcium-rich SN Ib (SN 2005CZ)
• Multi-Phase Dusty Gas in the Center of NGC 4278