1. Yuichi Terashima (Ehime U.)
Rare AGN Populations Found in the XMM-Newton Serendipitous Source Sample
Yuichi Terashima (Ehime U.)
``New Type of Obscured AGNs
(K. Noguchi, Y. Ueda)
Obscured AGNs in AKARI Infrared Sources
(Y. Hirata, H. Matsuhara, S. Oyabu)
Variability Selection of IMBH candidates
(N. Kamizasa, H. Awaki)

2. 1. Introduction Various populations must be sampled to understand AGN
unification/evolution.
Many serendipitous X-ray sources in the XMM archives.
Serendipitous source catalogue
~ sources listed
(CR in various bands,
hardness ratios, etc.)
Watson+09

3. Our Targets Obscured AGNs Low-mass Supermassive BHs
``New type’’:
large solid anlge is obscured by geometrically thick absorber
New Obscured AGNs in infrared sources
Low-mass Supermassive BHs
(or Intermediate-mass BHs)

4. 2. ``New Type’’ of Obscured AGNs
C: JAXA
Swift/BAT selected AGN
Suzaku follow up
Swift J0601 Ueda+07
Very weak scattering compont
``New Type’’:
Obscured by geometrically thick torus

5. New Sample of Obscured AGNs
Noguchi, YT+, ApJ, 2009, 2010 3％
0.5％
10％
1024cm-2 NH
f scat
our sample
1023cm-2
2XMM Catalogue
sources
Hardness selection
1-2, 2-4.5, keV
HR HR4
(keV)
Soft PL normalization
Hard PL normalization
32 objects selected
log NH 23-24, fscat <10%
XMM spectra analyzed
fscat =

6. Examples New Type (fscat < 0.5%): 8 objects found
fscat= F(0.5-2) / F(2-10) (absorption corrected)
fscat= 0.1％ fscat= 1% fscat= 10%
Photons/cm2 s keV
(keV)
　　　　　　　　　　　 　（keV）
　 （keV）
New Type (fscat < 0.5%): 8 objects found

7. L[OIII]/L2-10 vs fscat [OIII] optical narrow line:
photoionized gas in the
opening part of absorber
> 1 %
XMM sample
fscat < 1 %
Ueda+07 prediction
Weaker optical lines
expected for ``new type’’
Optically selected
sample
log L[OIII] / L2-10
Optical emission-
line selection:
biased against
objects with
small opening
angle
log L[OIII] / L2-10

8. 3 Obscured AGNs in Infrared Galaxies
Reprocessed IR emission from dust heated by central AGN is expected
IR selection effective to search for hidden AGNs
Spitzer+XMM/Chandra e.g., Poletta+08, Fiore+09, …

9. AKARI All Sky Survey AKARI + XMM catalog A New classification Diagram
Catalog URL:
9, 18, 65, 90, 140, 160 micron
micron
micron
sources
AKARI + XMM catalog
A New classification Diagram
New obscured AGNs
Blue: 9 mm
Green: 18 mm
Red: 90 mm

10. CR – FIR Diagram: Classification of Activity
NH = 0
cm-2
Sample: 272 objects
X-IR separation < 20 arcsec
|b| > 10 deg
18 mm & 90 mm quality flag = 3
Need only ``X-ray CR and IR flux’’
classification possible
w/out distance / spectra
● Seyfert 2
○ Seyfert 1
★HII
■LINER
□ transition
♢ambiguous
△unclassified
* Galactic
Ir units
CR – CR2-4.5
CR CR2-4.5
HR4 =

11. New AGNs PL = 1.8 fixed J0505 J0525 NH = 6.5x1023 cm-2
NH values
J0505
J0525
J0539
J0543
Hirata+, in prep

12. 4. Variability Selection of IMBHs
SMBHs have grown through mass accretion and merger.
Relatively low-mass SMBHs (or IMBHs <2x106Msolar): important class to understand AGN evolution.
X-ray variability time scale --- related to BH mass
Normalized excess variance (NXS):
NXS – MBH correlation
(e.g. Zhou+10, Ponti talk)

13. Selection Criteria Probability that the source is constant < 1×10-5
 718 sources in 2XMMi DR3 Not in SFR, SMC, LMC. Not stellar source Sources w/ Non-AGN type LC/Specta excluded  13 BLS1, 21 NLS1, 5 quasars, 2 unclassified AGN 3 NEW AGNs, Peculiar AGNs?
Probability that the source is constant < 1×10-5
Count rate in keV >= 0.1 counts/sec
Galactic latitude |b| >= 10° .

14. New AGNs: Light Curves and Spectra
Kamizasa+, in prep
MBH = 2.6x105Msolar
MBH = 1.1x106Msolar
MBH = 1.8x106Msolar
PL G = 1.83
BB kT=0.10 keV, PL G = 1.85
BB kT=0.14 keV, PL G = 2.35
Energy (keV)
Energy (keV)
Energy (keV)
BLS1-like
BLS1-like
NLS1-like

15. BH mass and Eddington Ratio40 41 42 43 44 45 46
106
107
108
log L2-10
MBH / M C
■ : Sy1 + Sy2 + QSO
■ : NLSy1
■ : Unclassified AGN
　 : Eddington luminosity
(Bolomtric correction factor 20
assumed)
5 objects: <106 Msolar
8 objects: Super Eddington
Variability selection --- effective to select growing BHs.

16. Peculiar AGN? No signal above 1.7 keV Optical (SDSS) counter part:
Terashima+, in prep
No signal above 1.7 keV
Optical (SDSS) counter part:
Galaxy at photo-z = 0.128
keV
3s uuper limit
(G=2 PL assumed)
MCD 0.21 keV or
compTT
kTe = 0.19 keV
t = 27
Energy (keV) PN
Soft thermal emission ONLY
AGN in High/Soft state?
-> Variability NOT compatible
New state or Extreme soft excess in NLS1?
MOS
Energy (keV)

17. Summary
2XMM catalogue: ``Rare’’ AGN population can be found by applying various selection criteria.
``New type’’ AGNs obscured by geometrically thick absorber found by HR-HR selection.
New X-IR diagram developed to efficiently classify activities.
4 New Obscured AGNs found
We constructed a new sample of IMBH candidates
3 NEW IMBHs and peculiar AGN candidate found.