XMM-Newton Observations ofNarrow-Line Seyfert 1 Galaxies

Luigi GalloMax-Planck-Institut für extraterrestrisch Physik

Many thanks to my advisors and collaborators: Y. Tanaka, Th. Boller, A. Fabian,

N. Brandt, S. Vaughan, G. Miniutti

Ringberg, 11 Apr. 2005 Luigi Gallo 2

Outline:

1. What are NLS1?2. XMM-Newton discovery of

sharp high-energy spectral drops 3. IZw1: lines and hard X-ray flares4. Flare model for NLS15. Other extreme observations

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Narrow-line Seyfert 1s: What are they?

�FWHM(Hβ) < 2000km/s

�[OIII]λ5007/Hβ < 3

�strong FeII emission

� ~ 15% of optically selected samples (e.g. Williams et al. 2002)� upto 50% of soft X-ray selected samples (e.g Grupe 1996)

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Extreme X-ray behaviourIRAS13224-3809

IRAS13349+2438

PHL 1092

RE J1034+393

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NLS1 are extreme, but not unique!

Gallo, Boller, Voges et al. (2004)Grupe (2004)

Brandt & Boller 1998

NLS1 and BLS1 form a continuous sequence in parameter space.

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XMM-Newton discovery of sharp spectral drops at E > 7 keV

IRAS 13224-3809 1H 0707-495

8.1 keV 7.5 keV

7 keV

Boller et al. (2003) Gallo et al. (2004)

� width is < 160 � 300 eV� no detection of accompanying Fe emission� drop energy changes with time

probably not due to photoionisation

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Several discoveries...IRAS 13349+2438 (Longinotti et al. 2003) NGC4051 (Pounds et al. 04; Uttley et al. 04)

PG1402+261 (Reeves et al. 2004)PG1211+143 (Pounds et al. 2003)

see also Foschini et al. (2004); Grupe et al. (2004)...

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Reflection and Light BendingFabian et al. (2004)

1H0707-495

Reflection dominatedspectrum

Continuumdominatedspectrum

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Partial Covering (eg. Holt et al. 80, Tennant 89, Abrassart & Czerny 00, Tanaka et al. 04)

1H0707-495

Gallo et al. (2004)

IRAS 13224-3809

Boller et al. (2003)

„lumpy accretion“„patchy absorber“

and other formshard

soft

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Partial covering or reflection?1H0707-495

2000

2002

Both models appear to work.Further observations can reveal the correct model!!!!

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XMM-Newton observation of the prototype NLS1 I Zw 1

ratio

ASCA observation of IZw1Very broad, strong, highly ionised iron line present in the ASCA data (Leighly 1999; Reeves & Turner 2000)

Gallo et al. (2004)

XMM-Newton data allow for the existence of multiple narrow iron lines.

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XMM-Newton detection of hard X-ray flaresI Zw 1 NAB 0205+024

Gallo et al. (2004)

Flare model (Galeev, Rosner, Vaiana 1979) seems particularly applicable to NLS1

Thanks to Rene Goosmann for figure

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Hot-spot emission lines?NAB 0205+024

Neutral disc line froman annular emission region?

Gallo et al. (2004)Also in II Zw 177?

Gallo et al. submitted

Reflected component arising from a hard X-ray flare.

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XMM-Newton discovery of other extreme behaviourShort-term variability in IRAS13224-3809

Gallo, Boller, Tanaka et al. (2004)

Hard band lags soft by 450 +/- 175 s

Possibly alternating lags:sometimes hard leads

Flux changes lead spectralvariability (hardness ratio)by 2000 +/- 1500 s

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XMM-Newton discovery of other extreme behaviourShort-term variability in PHL 1092

Gallo, Boller, Brandt et al. (2004)

Impressive X-ray variability.Simultaneous UV variability? Short-term spectral variability

L0.4-10 = 10 erg/s !!!!! 45

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Conclusions

Thank you!

� NLS1 are Seyfert 1 galaxies which show extreme behaviour

� XMM-Newton discovery of sharp spectraldrops at E > 7 keV � partial covering or reflection?

� flare model appears applicable to NLS1

XMM-Newton observations of NLS1 challenge our understanding of AGN, but at the same timeoffer a powerful laboratory for addressing these issues.