FERO: Finding Extreme Relativistic Objects

1
FERO Finding Extreme Relativistic
Objects (statistics of relativistic broad Fe K?
lines in AGN)
Anna Lia Longinotti (1), Ignacio de
la Calle (1), Matteo Guainazzi (1)
Stefano Bianchi (2) Michael Dovciak (3,4)

1. ESAC- European Space Astronomy Centre, Madrid,
   Spain
2. Universita degli studi Roma Tre, Italy
3. Astronomical Institute, Prague, Czech Republic
4. Academy of Scinces, Prague, Czech Republic

2
Outline

• Brief introduction on broad Iron lines
• Why are we interested in this work ?
• Description of the method the sample, the
  models, spectral fitting, results on lines
  detections
• Stacked spectra technique, trend of Fe line
  intensity with physical quantities of the sources
  
• Summary and future perspectives

3
Some Physics Fe K emission in AGN
Fe K transitions give rise to prominent
fluorescence lines in AGN spectra
Neutral Fe K? 6.4 keV Fe K?
7.06 keV (Reflection on distant torus) Fe XXV
6.7 keV Fe XXVI 6.97
keV (circumnuclear warm gas)
4
Some more Physics relativistic lines
Receding
approaching
Flux
Energy
If emission in inner disc, relativistic effects
modify line profile
NOT ALWAYS OBSERVED
5
Some History
Streblyanska 05 XMM-Newton Lockman Hole
(faint sources) EW500 eV F10-15-10-13
ergs/s/cm2
ASCA data 39 AGNs (Sy1 QSO) Nandra 97
Guainazzi 06 XMM-Newton 107 pointed AGN Broad
lines detected 25 of the total sample, EW 200
eV, strongest lines in low L sources
Broad lines detected in 38 XMM-Newton PG QSO
lt10 Jimenez-Bailon 05 Similar
results same sample Inoue 07
See talks by Nandra and Corral
6
Relevant Literature on broad lines
Observed in individual sources with XMM-Newton
(type 1) MCG-6-30-15 (Wilms 01, Fabian 02,
03) NGC3516 (Turner 02, 05) Mrk 335
(Longinotti 07) NGC4051 (Pounds
04) IRAS18325-5926 (Iwasawa 04) IRAS133492438
(Longinotti 03) 1H 0707-495 (Fabian 04)
more Sample of bright Seyfert 1 observed with
XMM-Newton and analysed homogeneously
relativistic emission required in 30 of the
sample. Nandra 07
PG1425267 (Miniutti Fabian 06) Q0056-363
(Porquet Reeves 03) PG1402261 (Reeves 04)
4U 1344-60 (Piconcelli 06)
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Why caring ?
Probe of strong gravity and accretion flow in
innermost region of AGN diagnostic of accretion
disc structure (extension, ionisation state),
potentiality to measure black holes spin. Very
common feature in ASCA spectra, not as common in
XMM-Newton and Chandra data

FERO
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FERO Sample description
161Radio-quiet type 1 AGN (NH lt 2-3 1022 cm-2
) observed by XMM-Newton
(MB gt -23)
(MB lt -23)
65 of sources FWHM H? available
Continuing studies on this sample IT effect
(X-ray Baldwin) on narrow Fe K line
Bianchi 07, AA X-ray general properties
(CAIXA project, Catalogue of AGN In
XMM-Newton Archive ) Bianchi in prep.
ltLxgt 1.11044 erg s-1
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Data and Analysis

• Data
• 221 XMM-Newton target observations,
  corresponding to 161 different sources
• obtained as pointed targets by XMM-Newton
  (public up to March 2007)
• Exposures 1- 400 ks (90 of observations lt
  100 ks)
• Only EPIC-pn data has been considered.

• Analysis
• Homogeneous analysis with latest SAS version
  and calibration
• Multiple observations in same observing mode of
  the same source combined
• (22 sources) into a single observation if
  Fx2-10keV and power-law index agree
• within errors . Otherwise, longest exposure
  included.

• Spectral Analysis
• Pre-analysis cut only source spectra with good
  statistic are fitted (gt17 d.o.f).
• Spectra rebinned with 25 background subtracted
  cts/channel, and gt 3 bins.
• Fit done in the 2 10 keV rest frame.
• Same model uniformly applied to the whole sample.

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The model
Primary X-ray power law warm absorbtion
Compton Reflection (cold) 5 narrow Fe K
lines

• X-ray nuclear source
• line of sight ionised gas
• molecular torus,
• circumnuclear material
• Accretion disc

6.4 keV ? Fe I K? 6.7 keV ?
Fe XXV 6.96 keV ? Fe XXVI 7.06 keV
? Fe I K? 6.3 keV ? Compton
Shoulder
Full relativistic treatment of accretion disc
line kyrline (Dovciak 04)

• Torus
• ? Ionised material

See Dovciak talk
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The adopted model

• Disc inclination in kyrline model limited lt 60?
• Reflection fraction and photon index limited
  according to BeppoSAX limits from a sample of
  Sy1 (Dadina 2008)
• Black Hole Spin, 3 test runs with spin0,1,free
  
  final run with spin FREE
• Assumption on Fe K Gaussian lines width
• Fe XXV XXVI width fixed to 1 eV
• Fe I K? width free to vary with upper limit fixed
  to optical FWHM, typically lt 60 eV, if no optical
  lines info available, width assumed to be 1eV

This model was defined after 7 previous test-runs
see I. de la Calles poster for more
details
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Results on individual detections
Classical red wing EW 102 eV
Line mimicking the continuum, fake profiles
After check on d.o.f. 149 sources
?5? detection
? upper limit (90
c.l.)
? above 1ct/s in RXTE Slew
Survey (Revnivtsev 04)
Double peak line EWlt 50 eV
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Detections Line Profiles I
Spectral ratios for detected lines in
well-exposed sources (cts2-10keV gt 1.5
105 cts)
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Detections Line Profiles II
Spectral ratios for detected lines in
under-exposed sources cts2-10keV lt 1.5 105 cts
Fake line profile continuum fit Border-line
source known to have a complex 2-10 keV spectrum,
could be partial covering (Longinotti03)
IIZW177
NGC 985
MR2251-178
PDS 456
IRAS133492438
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List of Detections
1044 erg/s
Source name Type Cts 2-10 keV L 2-10
keV EW (ev) ?
MGC-6-30-15 ? BLQ 13.92e05 0.057 110 12 15.8
NGC3783 ? BLSY 9.4e05 0.113 87 10 13.3
IC4329A ? BLSY 9.1e05 0.564 40 13/-6 10.0
NGC3227 ? BLSY 3.5e05 0.011 66 25/-11 9.8
MRK509 ? BLQ 7.4e05 1.038 133 22 9.7
MGC-5-23-16 ? NCSY 8.8e05 0.142 35 10/-6 9.7
ESO511-G030 ? NCSY 1.7e05 0.224 56 30/-10 8.7
NGC4593 ? BLSY 2.4e05 0.073 65 20/-13 8.1
MRK766 ? NLSY 7.8e05 0.061 180 68/-40 7.2
MR2251-178 ? BLQ 1.0e05 2.177 60 40/-14 6.8
MRK335 ? NLSY 2.0e05 0.275 35 25/-10 5.8
NGC4051 ? NLSY 2.0e05 0.003 260 56/-77 5.5
IRAS133492438 BLQ 0.08e05 0.782 690 215 5.5
NGC985 ? BLSY 0.3e05 0.403 110 22 5.4
AKN564 ? NLSY 1.9e05 0.246 22270 5.2
PDS456 ? NCQ 0.3e05 8.485 80 25 5.2
IIZW177 ? NCSY 0.01e05 0.148 570 2200/-185 5.0
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Disc parameters versus Line EW
Radial dependence for disc emissivity j ? r-?
Spin of the black hole
Disc inclination angle
ltigt2320
lt?gt3.12.3
IC4329A i28 6/-11? NCG3227
i23 4? MCG-5-23-16 i208/-3?
ESO511-G030 i177 ? NGC4593 i1817/-4
? MRK766 i362 ? MRK335
i2410 ? NGC4051 i226 ?
MCG-6-30-15 a 0.530.09/0.06
MCG-6-30-15 ?3.280.10 NGC3783
?2.700.09/-0.15 NGC3227 ?1.870.54
MRK766 ?3.111.66/-0.75 NGC4051
?2.890.35
Only good detections plotted
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EW versus physics any dependence ?
65 of the sample
(all sources)
Fe line EW versus accretion rate
Fe line EW versus X-ray (2-10 keV) Luminosity

Fe line EW versus Black Hole Mass
Only good detections plotted
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Stacked spectra source types
EW402 eV
EW255 eV
EW estimated in 4-7 keV
All Sey
All QSO
EW725 eV
EW353 eV
Broad Line Objects (28 SY32 QSO)
Narrow Line Objects (17 SY13QSO)
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Results on Flux-Limited sample
Within our collection of archival AGN, we are
building a flux-limited sample aiming at
including all sources above 1ct/s (3-8 keV) in
RXTE Slew Survey (Revnivtsev 04) that follow the
criteria of radio-quietness and Nh used to select
the initial database. 33 sources in XSS with
these characteristics 31 are already in XMM
archive (and in our analysis) ?
Detections rate 11/31 (3512 ) Percentage of
EW lt100 eV 64 ltEWgt (weighted mean)644
eV ltEWgt11074 eV
Variability not addressed, but see De Marcos talk
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Pre-conclusion
How often relativistic broadening appears in AGN
spectra?
Is there any relation with disc parameters or
source properties ?
FERO
8 of the full sample 149 sources 35 of the
Flux-Limited sample
No obvious relation found from our analysis
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Conclusions
From analysis of individual sources
Broad Fe line are weak, not ubiquitous. No
observation of extreme relativistic lines

• Full sample 12/149
• Flux Limited sample 11/31
• Mean EW634 eV
• No detection EWgt 250 eV
• No trend with disc parameters

Broad Fe line not related to physical parameters
of the source, although QSO show weaker lines
than Sy Intriguing and possible intrinsic
difference between NL and BL sources need to be
investigated in detail
From stacked spectra analysis

• No evident trend with Lx, BH mass or L/Ledd
  detections concentrated in low luminosity sources
  but photon statistics still not sufficient
• NL objects appear to have broad line EW higher
  than BL sources

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The future

1. Ultimate the analysis of any possible correlation
   of line EW in a more precise way
2. Refine the analysis in stacked spectra,
   particularly on the dichotomy NL/BL sources
3. Try to complete the flux limited sample with
   longer exposures to ensure high photon statistics
   (i.e. XMM proposals)
4. Build XEUS