A Relation of the PAH 3.3 mu m Feature with Star-forming Activity for Galaxies with a Wide Range of Infrared Luminosity

作者：Yamada Rika^*; Oyabu Shinki; Kaneda Hidehiro; Yamagishi Mitsuyoshi; Ishihara Daisuke; Kim Ji Hoon; Im Myungshin

来源：Publications of the Astronomical Society of Japan, 2013, 65(5): UNSP 103.

DOI：10.1093/pasj/65.5.103

• galaxies: active
• galaxies: starburst
• infrared: galaxies

For star-forming galaxies, we investigated a global relation between the polycyclic aromatic hydrocarbon (PAR) emission luminosity at 3.3 mu m, L-PAH3.3, and the infrared (8-1000 mu m) luminosity, L-IR, to understand how the PAH 3.3 mu m feature relates to star-formation activity. With AKARI, we performed near-infrared (2.5-5 mu m) spectroscopy of 184 galaxies having L-IR similar to 10(8)-10(13) L-circle dot. We classified the samples into infrared galaxies (IRGs: L-IR %26lt; 10(11) L-circle dot), luminous infrared galaxies (LIRGs: L-IR similar to 10(11)-10(12) L-circle dot) and ultra-luminous infrared galaxies (ULIRGs: L-IR %26gt; 10(12) L-circle dot). We excluded sources likely to be contaminated by AGN activity, based on the rest-frame equivalent width of the PAR emission feature (%26lt; 40 nm) and the power-law index, representing the slope of continuum emission (Gamma %26gt; 1; F-nu proportional to lambda(Gamma)). Of these samples, 13 IRGs, 67 LIRGs, and 20 ULIRGs show the PAR emission feature at lambda(rest) = 3.3 mu m in their spectra. We find that the L-PAH3.3/L-IR ratio considerably decreases toward the luminous end. Utilizing the mass and temperature of dust grains as well as the Br alpha emission for the galaxies, we discuss the cause of the relative decrease in the PAH emission with L-IR.

• 出版日期2013-10-25