Survey of dusty AGNs based on the mid-infrared all-sky survey catalog Shinki Oyabu (Nagoya University) & MSAGN team
Search for Active Galactic Nuclei Purpose 1 The MIR selection can minimize wavelength-dependent selection effects. The UV and optical emission is easily affected by dust extinction. The radio emission shows big variety. Thus, we can make the unbiased statistical studies. How much are the space densities of Seyfert 1 and Seyfert 2? Are all Seyfert 2 really explained to be miss-aligned Seyfert 1? What kind of galaxies are the hosts of AGNs? Spinoglio et al. 1995 2011/12/16 AKARI Extragalacitc Science Workshop 2
According to synthesis models of the X-ray background (XRB; e.g. Ueda et al. 2003), much of the peak intensity of the XRB at 30 kev should be produced by AGNs subject to absorption with a line-of-site hydrogen column density lognh (cm^-2)> 23.5. Purpose 2 The number density of such AGNs is a key parameter in understanding the accretion history of the universe. Ueda et al. 2003 2011/12/16 AKARI Extragalacitc Science Workshop 3
Purpose 3 Using all-sky survey with new sensitivity, we can collect missing population from current catalogs. We can extend the faint end of nearby AGN luminosity functions using new sensitivity as well as the bright end of the distant AGNs using the survey area. How many AGNs do we miss to collect? IRAS discovered highly reddened and buried AGNs. (e.g. Beichman et al. 1986) Beichman et al. 1986 2011/12/16 AKARI Extragalacitc Science Workshop 4
2011/12/16 AKARI Extragalacitc Science Workshop 5 Mid-infrared search for AGNs If we use MIR bands, we can detect thermal emission from dusty torus of AGNs if they are buried or not. Elvis et al. 1995 IRAS 12micron follow-up (Rush et al. 1993) IRAS ~300mJy at 12μm AKARI 50mJy at 9μm ISOCAM parallel mode survey (Haas et al. 2003, Leipski et al. 2005) was deeper than AKARI all-sky survey, but a survey area was only 10 square degrees.. Spitzer
AKARI MIR All-Sky Survey Zodiacal light was removed with a simple way in this map. The star atlas was made by Nagoya City Museum using Stellar Navigator (Astro. Arts Co.). 9 ミクロン Table 1 Performance summary Channel S9W L18W Wave coverage 6-12um 14-26um Detection limit (5σ) 50 mjy 90 mjy Saturation (80% linearity) < 300 Jy Spatial resolution < 9.4 2011/12/16 6 Ishihara et al. 2010
2011/12/16 AKARI Extragalacitc Science Workshop 7 Target Selection Elvis et al. 1995 AKARI mid-infrared all-sky survey catalog b <30, LMC, and SMC regions are excluded. Identified with 2MASS Normal Galaxies Criteria of MIR excess F(9μm)/F(Ks)>2 QSO template ~1500 Candidates Famous objects are also included. Blackbody
2011/12/16 AKARI Extragalacitc Science Workshop 8 There is a problem.. We suffer from the contamination of PAH strong galaxies like M82. We need AKARI Phase 3 spectroscopy. AKARI Phase3(Post Helium mission) Mid-infrared Search for AGN (MSAGN;PI S.Oyabu) IRC NG(R~100)spectroscopy AKARI NG spectroscopy M82 z=0 z=0.3 QSO z=3 z=1 z=0.5 Ks S9W L18W
Result In MSAGN, we took 94 spectra. AGN like AGN-like 42 PAH galaxy 38 red stars 9 Galaxies without features 5 PAH galaxy like We also performed optical spectroscopy from the ground. 2011/12/16 9
Dusty AGNs from AKARI all-sky survey Oyabu et al. (2011) AKARI NIR spectra Optical spectra from Lick LEDA 84274 IRAS 01250+2832 Only AKARI found the evidence of AGN on these galaxies at z=0.04. vlv(l_sun) IRCS/AO188 images 1 10 100um 1 10 100um J K M 4000 6000 8000AA 4000 6000 8000AA
2011/12/16 AKARI Extragalacitc Science Workshop 11 Situations (Cartoons) 1pc 1pc Much bigger AGN Dust 500K surface OB stars OB starts that produce more than 10^10 Lsun in 1 cubic persec is quite unreasonable. Crossing and relaxation times are 10000yr and 1Myr, respectively. If the situation is 1000 ~ 10000 massive star forming regions with 500k dust, we can explain our 500k dust detection. This is reliable?????
The properties of dusty AGNs 10 12 LEDA 84274 IRAS 01250+2832 75K 10 12 500K vlv(l_sun) 10 10 600K vlv(l_sun) 10 10 85K 1 10 100um 1 10 100um Host galaxy type Late-type Early-type Dust mass (β=1) 1x10 6 M_sun 3x10 5 M_sun SFR 25M_sun yr -1 No evidence
2011/12/16 13 AGNs and the host galaxies LEDA 84274 Dn(4000)=1.1 Galaxy mass: 6x10^9 M_sun IRAS 01250+2832 Dn(4000)=1.6 Galaxy mass: 4x10^9 M_sun Kauffmann et al. 03
We found two more candidates. Dusty AGN candidates 10 12 10 12 vlv(l_sun) 10 10 6dF Spectrum z=0.019 SDSS Spectrum z=0.05 vlv(l_sun) 10 10 2.5 um 5.0um 2.5 um 5.0um
2011/12/16 15 AGNs and the host galaxies LEDA 84274 Dn(4000)=1.1 Galaxy mass: 6x10^9 M_sun IRAS 01250+2832 Dn(4000)=1.6 Galaxy mass: 4x10^9 M_sun MSAGN 1920074 Galaxy mass: 3x10^9 M_sun Kauffmann et al. 03
2011/12/16 AKARI Extragalacitc Science Workshop 16 Summary We are performing AGN search with AKARI MIR All-Sky Survey and AKARI NIR spectroscopy. We detected red continuum radiated from hot dust in infrared galaxies. The suitable explanation is the existence of AGNs. But, the galaxies do not have any evidences of AGNs in other wavelengths.