Characteristics of mid-infrared PAH emission from star-forming galaxies selected at 250 μm in the North Ecliptic Pole field

PASJ: Publications of the Astronomical Society of Japan

Seo, Hyunjong¹  Varillas, Maria del Carmen Campos²  Pearson, Chris³  Hashimoto, Tetsuya⁴  Jeong, Woong-Seob⁵  Barrufet, Laia⁵  Goto, Tomotsugu⁵  Shim, Hyunjin⁵  Kim, Minjin⁵  Kim, Seong Jin⁶  Chiang, Chia-Ying⁶  Lee, Hyung Mok⁶  Im, Myungshin⁷  Matsuhara, Hideo⁸ 

[1] Astronomy Program, FPRD, Department of Physics and Astronomy, SNU, Kwanak-Gu, Seoul 151-742, Korea;Department of Astronomy and Atmospheric Sciences, Kyungpook National University, Daegu 702-701, Korea;Department of Earth Science Education, Kyungpook National University, Deagu 41566, Korea;Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 229-8510, Japan;Korea Astronomical Space Science Institute, 61-1, Whaam-dong, Yuseong-gu, Deajeon 305-348, Korea;National Tsing Hua University No. 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan;RAL Space, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, UK;The Open University, Milton Keynes, MK7 6AA, UK

关键词: cosmology: observations;    infrared: galaxies;    galaxies: evolution;   

DOI  :  10.1093/pasj/psy121

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

Evolutionary properties of infrared (IR) luminous galaxies are important keys to understand dust-obscured star formation history and galaxy evolution. Based on near- to mid-IR imaging with nine continuous filters of the AKARI space telescope, we present the characteristics of dusty star-forming (SF) galaxies showing polycyclic aromatic hydrocarbon (PAH) features observed by the North Ecliptic Pole (NEP) wide field survey of AKARI and Herschel. All the sample galaxies from the AKARI/NEP-Wide data are selected based both on the Herschel/SPIRE 250 μm detection and optical spectroscopic redshift data. The physical modeling of spectral energy distribution (SED) using all available data points from u* to sub-mm 500 μm band, including WISE and PACS data where available, takes unique advantages of the continuous near- to mid-IR coverage, the reliable constraint on the far-IR peak, and spectroscopically determined accurate redshifts, as well as the energy balance principle by MAGPHYS. This enables us to derive physically meaningful and accurate total infrared luminosity and 8 μm (or PAH) luminosity consistently. Our sample galaxies are in the redshift range |$z$| < 1, and the majority of them appear to be normal SF/spiral populations showing PAH features near 8 μm. These SF galaxies showing PAHs in the mid-IR include various types, from quiescent to starbursts. Some of our sample show shortage of 8 μm luminosity compared to the total IR luminosity and this PAH deficit gets severe in more-luminous IR galaxies, suggesting PAH molecules in these galaxies are destroyed by a strong radiation field from the SF region or a large amount of cold dust in the interstellar medium. The specific SFR of our sample shows mass-dependent time evolution which is consistent with a downsizing evolutionary pattern.

【 授权许可】

CC BY