천문학논총 (Publications of The Korean Astronomical Society)

  • 제27권4호
  • /
  • Pages.265-270
  • /
  • 2012
  • /
  • 1225-1534(pISSN)
  • /
  • 2287-6936(eISSN)
한국천문학회 (The Korean Astronomical Society)
권호 표지
DOI QR코드

DOI QR Code

SURVEY OF DUSTY ACTIVE GALACTIC NUCLEI BASED ON THE MID-INFRARED ALL-SKY SURVEY CATALOG

  • Oyabu, S. (Graduate School of Science, Nagoya University) ;
  • Ishihara, D. (Graduate School of Science, Nagoya University) ;
  • Yamada, R. (Graduate School of Science, Nagoya University) ;
  • Kaneda, H. (Graduate School of Science, Nagoya University) ;
  • Yamagishi, M. (Graduate School of Science, Nagoya University) ;
  • Toba, Y. (Instituted of Space and Astronautical Science, Japan Aerospace Exploration Agency) ;
  • Matsuhara, H. (Instituted of Space and Astronautical Science, Japan Aerospace Exploration Agency) ;
  • Nakagawa, T. (Instituted of Space and Astronautical Science, Japan Aerospace Exploration Agency) ;
  • Malkan, M. (Department of Physics and Astronomy, University of California) ;
  • Shirahata, M. (Instituted of Space and Astronautical Science, Japan Aerospace Exploration Agency)
  • 투고 : 2012.07.01
  • 심사 : 2012.08.20
  • 발행 : 2012.09.16
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

Many observations have found evidence of the presence of a large number of heavily obscured Active Galactic Nuclei (AGNs). However, the nature of this population is only poorly understood because heavy obscuration by dust prevents one from finding them at optical wavelengths. Mid-infrared AGN searches can overcome this obstacle by penetrating through dust and by detecting direct emission from the dust torus. Thus, we can identify most of the AGN population, including type-2 and buried AGNs. Using the AKARI mid-infrared all-sky survey, we performed an AGN search in the nearby universe. Utilizing the 2MASS photometry, we selected mid-infrared-excess sources and carried out near-infrared spectroscopic observations in the AKARI Phase 3. During these follow-up observations, we have found three galaxies that show strong near-infrared red continuum from hot dust with a temperature of about 500 K, but do not show any AGN features in other wavelengths. The most suitable explanation of near-infrared continuum is the presence of central AGNs. Therefore, we conclude that they are AGNs obscured by dust. We performed X-ray observations of the two galaxies with SUZAKU. No detections in the 0.4-10 keV suggest that the column density may be much higher than $N_H=10^{23.5}cm^{-2}$. Comparing the masses of the host galaxies with those of the SDSS AGNs, we find that the host galaxies of the dusty AGNs discovered with AKARI are less massive populations than those of optically selected AGNs.

키워드

참고문헌

  1. Cowie, L., Songaila, A., Hu, E. M., & Cohen, J. G., 1996, New Insight on Galaxy Formation and Evolution From Keck Spectroscopy of the Hawaii Deep Fields, AJ, 112, 839 https://doi.org/10.1086/118058
  2. Cutri, R. M., Nelson, B. O., Francis, P. J., & Smith, P. S., 2002, The 2MASS Red AGN Survey, ASPC, 284, 127
  3. Ferrarese, L. & Merritt, D., 2000, A Fundamental Relation between Supermassive Black Holes and Their Host Galaxies, ApJL, 539, 9 https://doi.org/10.1086/312838
  4. Heckman, T. M., et al., 2004, Present-Day Growth of Black Holes and Bulges: The Sloan Digital Sky Survey Perspective, ApJ, 613, 109 https://doi.org/10.1086/422872
  5. Imanishi, M., et al., 2008, Systematic Infrared 2.5-5 m Spectroscopy of Nearby Ultraluminous Infrared Galaxies with AKARI, 60, 489
  6. Ishihara, D., et al., 2010, The AKARI/IRC Mid- Infrared All-Sky Survey, 2010, A&A, 514, 1
  7. Jones, D. H., et al., 2009, The 6dF Galaxy Survey: Final Redshift Release (DR3) and Southern Large- Scale Structures, MNRAS, 399, 683 https://doi.org/10.1111/j.1365-2966.2009.15338.x
  8. Kauffman, G., et al., 2003, The Host Galaxies of Active Galactic Nuclei, MNRAS, 346, 1055 https://doi.org/10.1111/j.1365-2966.2003.07154.x
  9. Kormendy, J. & Richstone, D., 1995, Inward Bound- The Search For Supermassive Black Holes In Galactic Nuclei, ARA&A, 33, 581 https://doi.org/10.1146/annurev.aa.33.090195.003053
  10. Gahndi, P., et al., 2009, Resolving the Mid-Infrared Cores of local Seyferts, A&A, 502, 457 https://doi.org/10.1051/0004-6361/200811368
  11. Glikman, E., et al., 2004, FIRST-2Mass Sources below the APM Detection Threshold: A Population of Highly Reddened Quasars, ApJ, 607, 60 https://doi.org/10.1086/383305
  12. Haas, M., et al., 2003, The ISO View of Palomar- Green Quasars, A&A, 402, 87 https://doi.org/10.1051/0004-6361:20030110
  13. Leipski, C., et al., 2005, The ISO-2MASS AGN Survey: on the Type-1 Sources, A&A, 440L, 5
  14. Low, F. J., Cutri, R. M., Huchra, J. P., & Kleinmann, S. G., 1988, Infrared Color-Selected Quasars and Seyfert 1 Galaxies, ApJL, 327, 41 https://doi.org/10.1086/185136
  15. Maiolino, R., et al., 1998, Heavy Obscuration in X-ray Weak AGNs, A&A, 338, 781
  16. Oyabu, S., et al., 2011, AKARI Detections of Hot Dust in Luminous Infrared Galaxies. Search for Dusty Active Galactic Nuclei, A&A, 529, 1220
  17. Polletta, M., et al., 2007, Spectral Energy Distributions of Hard X-Ray Selected Active Galactic Nuclei in the XMM-Newton Medium Deep Survey, ApJ, 663, 81 https://doi.org/10.1086/518113
  18. Rush, B., Malkan, M. A., & Spinoglio, L., 1993, The Extended 12 Micron Galaxy Sample, ApJS, 89, 1 https://doi.org/10.1086/191837
  19. Sanders, D. B., Soifer, B. T., Elias, J. H., Neugebauer, G., & Matthew, K., 1988, Warm Ultraluminous Galaxies in the IRAS Survey - the Transition from Galaxy to Quasar?, ApJ, 328, 35 https://doi.org/10.1086/185155
  20. Sanders, D. B. & Mirabel, I., 1996, Luminous Infrared Galaxies, ARA&A, 34, 749 https://doi.org/10.1146/annurev.astro.34.1.749
  21. Ueda, Y., Akiyama, M., Ohta, K., & Miyaji, T., 2003, Cosmological Evolution of the Hard X-Ray Active Galactic Nucleus Luminosity Function and the Origin of the Hard X-Ray Background, ApJ, 598, 886 https://doi.org/10.1086/378940
  22. Voges, W., et al., 2000, ROSAT All-Sky Survey Faint Source Catalogue, IAU Circ, 7432, 3