thomas boller max-planck-institut für extraterrestrische physik, garching
DESCRIPTION
AGN Science learned from previous missions: Issues for the coming decade. Thomas Boller Max-Planck-Institut für extraterrestrische Physik, Garching. (i) How to interprete the nature of the soft X-ray emission. (ii) Sharp spectral drops in the HE spectra of NLS1s. - PowerPoint PPT PresentationTRANSCRIPT
Thomas BollerMax-Planck-Institut für extraterrestrische Physik, Garching
AGN Science learned from previous missions:Issues for the coming decade
2 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
(i) How to interprete the nature of the soft X-ray emission
(ii) Sharp spectral drops in the HE spectra of NLS1s
(v) Chemical abundances of the SB component
(vi) Dark Matter determination via chemical abundances
(iii) Single Thermal Comptonization
(iv) Search for gravitativ redshifted X-ray/optical lines in BLR
3 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
(i) How to interprete the nature of the soft X-ray emission
Reflection spectrum interpretation
or
Thermal disc interpretation
4 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Energy [keV]
1H0707-495 Boller 2002,3Tanaka 2004Gallo 2004
Phot
ons
cm-2 s
-1 k
eV-1
Thermal disc interpretation
The high T can be recovered by considering super-Eddington accretion
Rather uniform shape of the soft-excess
a characteristic T of about 120 eV emerges, the spread inT is small, however the L in samples span three orders of mag. This is not simple to understand in terms of any existing accretion disc theories.
Ross & Fabian suggest that the soft-excess is explained by blurred emission lines and bremsstrahlung from the hot disc surface
Benefit of the reflection model is that the bumps in the soft energy band of 1H0707 can be naturally attributed toreflection as a complex Fe-L lines
Energy [keV]
Reflection spectrum interpretation
Fabian 2004
5 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Assuming the Thermal disc interpretation is correct
Physical relevant AGN parameters can be derived:
BH MassEddingtion accretion rate (efficiency of accretion)
Number of associated relations
Eddington accretion rate versus spectral complexityEddington accretion rate versus metallicity
6 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Accretion-rates dependence on Black hole masses
NLS1s
BLS1s
NLS1s
LINERs
BLS1s
LINERs
LINERcaveates:
- separate nuclear emission
-following Hagai´s comment: if SLOAN people are right, LINERs shift up
7 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Spectral complexity obtained via a simple power-law fit
Present in Super-Eddingtonaccretion rate objects
8 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
fit in the 2-10 keV range
LINERS often as a simple power-law
NLS1s more complex - soft excess - spectral curvature - sharp spectral drops
Spectral complexity correlates with accretion rate
9 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Metallicity dependence on the accretion rate
13224 with super-Eddington accretion
Fe overabundance 3-10 required in all NLS1s with sharp spectral drop, even for reflection dominated model
Boller et al. 2003 Netzer et al. 2004
Clear trend of FeII/H with accretion rate for NLS1 and high-z QSO
optical Fe II emission increases withaccretion rate
10 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
(ii) Sharp spectral drops in the HE spectra of NLS1s
The sharpness of the feature - most fundamental discriminator between thermal and reflection models -feature always sharp (<150 eV, resolution of the EPIC pn detector) in case of neutral absorption, whereas it will be broader in the line interpretation
- The measurements can rule out high photoionization,but is still not sufficient to exclude either partial covering or reflection, though it becomes a concerning for reflection
11 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
The sharpness of the feature
1H0707-495 (2000)
12 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
The (time-dependent) energy of the feature
First detection of a sharp spectral drop was in 1H0707 at an energyof 7.1 +-0.1 keV, perhaps coincidently, entirely consistent with the neutral Fe edge
However, it was the last time that an edge was detected at this energy.
The second observation of 1H0707 found the edge at 7.5 keV.
It appears unlikely that the edges are ionised, since there are no traces in the spectra for increased ionisation (e.g. no broading of the edge, no KUTA absorption).This requires a huge mass and energy loss rate in the outflow, it remains uncertain how huge outflows can alter the appearence of theedge.
The edge energy is difficult to explain in terms of reflection. Even inthe most extreme light bending scenarios, it is difficult to achieve sucha sharp feature at high energies of 8.2 keV (found in IRAS 13224).
13 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Details of the deep spectral drop:relevant for high accretion rates
drop energy not always the samefor 1H 0707, it strikingly it shifted from 7.1 to 7.5 keV (>5 )for IRAS 13224 is found even higher at 8.2 keV
PCM: higher ionization (Fe VII-X, Fe XIX-XXIII) unlikely, missing K absorption high outflow v of 0.05 and 0.15 c required
RDM: energy shift due to different
IRAS 13224-3809
8.2 keV
Energy [keV]
1H0707-495
7.1 keV in 2000
7.5 keV in 2002
Energy [keV]
Cou
nts
s-1 k
eV-1
14 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
XMM-Newton cannot disentangle absorption from reflection
Photoelectric absorption
1H0707-495 Boller 2002,3Tanaka 2004Gallo 2004
Energy [keV]
Phot
ons
cm-2 s
-1 k
eV-1
Energy [keV]
Cou
nts
s-1 k
eV-1
X-ray reflection (light bending)
1H0707-495 Fabian 2002Miniutti 2003Fabian 2004
keV
(keV
cm
-2 s
-1 k
eV-1)
Energy [keV]
Cou
nts
s-1 k
eV-1
Energy [keV]
ratio
15 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Drawbacks from the simplified picture
Reflection: when reflection dominates the 1 keV bumps would be most prominent when the source is the low state, and then should diminish as the power-law components emerges however, the 1 keV feature were not al all visible during the low state observations in 2000
According to Fabian 2002 the spectrum was a contrived mixture ofthree separate reflectors, which would result in blending out anydistinct features
The high-flux state (Leighly 2002) is realised by the emergence of thepower-law component and minimasion of the reflection component. However, the soft excess was still dominated over the power-law, andthe 1 keV bumps were still present, both should be significantly suppresed(and statistically insignifanct given the smaller collecting area of Chandra)
16 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Spectral Variability
Significant spectral variability in 1H0707 and IRAS 13224more significant in the 1-5 keV band
Fabian 2004 showed that this can be explained by a variable PL, dominatingthe 1-5 keV band and less variable reflection <1 and > 5 keV
Situation more complicated for the PC scenarioa DOUBLE PC is required to explain the situation
Another point of concern:The amplitude of the variations.In the light bending model the variability should be depressed duringThe reflection dominated low flux state.The opposite is observed in 1H0707!
And:The detection of especially alternating lags, between various energybands in IRAS 13224 is a serious challange for both models
17 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Reflextion model in different flux states
Energy [keV]
flux
low flux state
high flux statepower-lawreflection component
18 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Steepness of the soft and hard X-ray spectra
The steeper continuum slopes in the 0.1-2.4 keV band may be moredifficult to understand if the soft-excess is a reflection componentrather than a thermal one.
In addition:Both reflection and PC flatten the spectrum above, 2 keV, butNLS1s tend to show stepper hard X-ray slopes (Brandt 1997)
19 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Advantages from the simplied picture
Both models, optically thick thermal emission and relativistically blurredemission result in statistically acceptable fits with XMM-Newton
The Fe K line is diminishing when the flux is increasing (reflection adv.)
The column density increases when the flux is decreasing (bbody adv.)
If the soft excess is thermal and the partial covering model is correct,BH Masses and BH Growth rates can be determined, independent ofother methods
20 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Spectral changes in dependence of the flux state
In the high state, Fe K Linie is dimishing
21 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Alternatives to waiting 10 years for XEUS
High-quality XMM-Newton observations of NLS1s in different flux states should distinguish between the models (300 ks), as PC and LBwill lead to quite different spectra
The intrinsic X-ray spectrum is highly absorbed in the PC case, thereforeExtreme variations of _ox could be an indicator of PC
IRAS 13224 and 1H0707 are extreme, but not unique.As such, there shoud be many more similar objects (in progress)
22 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Issues for the coming decadeXEUS simulations
Reflection model fitted with thermal emission from the disc
Thermal model fitted with ionizedreflection from the disc
23 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
(iii) Single Thermal Comptonization
Hot accretion disc e-1 layers produce via inverse Comptonisation power-law spectral distribution
Examples: TonS 180, Mrk 110
Second power-law required as a consequence of inverse Compton scattering of an hot electron layer above the accretion disc
Single thermal comptonization can be well constrained with XMM-Newton, butHybrid thermal/non-thermal electron layers remain unconstrained
24 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Thermal Comptonisation in Mrk 110
Thermal comptonization gives a temperature of 60+-20 keV of the disc layer and the Compton parameter is a function of the Photon index .
This means that it is not possible to solve for both the optical depth and kT for the hot electron layer
The model
X-ray emission lines from SB
IC
corona
Energy [keV]
Ph
oto
ns [
cm
-2 s
-1 k
eV
-1]
XMM-Newton spectral fit
Energy [keV]
Cou
nts
[ s
-1 k
eV
-1]
25 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Hybrid thermal/nonthermal electron distribution
Not constrained with the present XMM-Newton statistics
Lorentz factors, soft compactness and non-thermal compactness parameters cannot be uniquiqly determined with the present statistics
XEUS simulation show that kT of the hybrid layer, Lorentz factors,compactness and SB abundances parameters will be constrained
50 ks XEUS simulation
Energy [keV]
Counts
[s-
1 k
eV
-1]
26 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
Broad O VII triplet in Mrk 110 (Boller, Balestra 06)
Oxygen triplet
O VII ( r ) E=(572.5-0.3+0.4) eV O VII ( i ) E=(568.1-0.7+0.4) eVO VII ( f ) E=(561.9-0.4+0.8) eV
Broad component
E = (554.0-3.0+2.0) eV
THE DISPLACEMENT OF THE BROAD LINE WITH RESPECT TO THE MEAN VALUE OF THE 3 OXYGEN LINES IS 566.9-554.0 =12.9 eV CORRESPONDING TO z = 0.0228, FWHM ~9000 km s-1
Opitcal lines from Kollatschny do have smaller FWHM and smaller z
A fit with a relativistic profile gives the same with thefollowing best fit parameters:
E=(531.9+-0.2) eVR_in=(150-50
+150) r_gR_out=(3000-1500
+3000) r_gi=(31-5
+4) dg
Grav. red. X-ray linein the BLR
Similar results obtained byCostantinie (2006)
Consistent with calculations fromA. Müller (XMM talk next week)
(iv) Search for gravitativ redshifted X-ray/optical lines in BLR
27 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
(vi) Chemical abundances of the SB componentExamples: NGC 6240 and Mrk 110Element abundances not constrainedvapec code does not find the abundances values for most of the elements
0.3 1.0 2.0 5.0 10 Energy [keV] (observers frame)
C
ount
s s-1
keV
-1
10-3
10-2
10-1
D
ata /
Mod
el0
1
2
kT = 0.7 keV
kT = 1.4 keV
kT = 5.5 keVFe XXV,XXVI
NH = 1024 cm-2
AGN-Fe Ka in reflection-Highly absorbed PL component
Starburst contribution3 plasma-components
28 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
The power of combining Chandra with XMM-Newton
0.5 1.5 5 10 keV
T-gradient NH-gradient [keV] [cm-2]RED 0.5-1.5 0.2 1022 YELLOW 1.5-5.0 0.4 1022
WHITE 5.0-10.0 4.1 1022
Chandra image binned in energy according to XMM-Newton spectral results
29 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
(vii) Dark Matter determination
In addition to WMAP, eROSITA, SN, cluster measurements and can also be constrained from element abundances ofdistant quasars
> 0.78
Alcaniz et al. 03
Detection of a 2-Gyr-old quasar at z=3.91 (Hasinger et al. 2003) is of particularly interest as it constrains the amount of dark energy
30 Present and future AGN science issues Thomas Boller, MPE Garching
Tokyo workshop 2006
(i) How to interprete the nature of the soft X-ray emission
(ii) Sharp spectral drops in the HE spectra of NLS1s
(v) Chemical abundances of the SB component
(vi) Dark Matter determination via chemical abundances
(iii) Single Thermal Comptonization
(iv) Search for gravitativ redshifted X-ray/optical lines in BLR
THE END - THANKS