The High Energy Emission of NGC 1365 and 1H 0419-577

The High Energy Emission of

NGC 1365 and 1H 0419-577

Prague: 2010

DOM WALTON

IoA, Cambridge

In collaboration withRubens Reis and Andy Fabian

OVERVIEW

A (really quick) reminder of disc reflection

Describe 'Hard Excesses' and their current interpretations

Present a disc reflection interpretation for SUZAKU observations of NGC 1365 and 1H0419-577

Dom Walton Prague: 2010

DISC REFLECTION


SPOT THE SIMILARITY


Prague: 2010Dom Walton

SPOT THE SIMILARITY

ARABIAN CAMEL


ARABIAN CAMEL

Hump


REFLECTION SPECTRUM


REFLECTION SPECTRUM

Hump


HARD EXCESSES?

Ratio plots to a powerlaw continuum fit to the 2-4 and 7-10 keV energy ranges

Both sources display strong emission above 10 keV

Previous authors (Risaliti, Braito, et al. 2009, Turner et al. 2009) have claimed disc reflection models alone cannot reproduce the high energy emission.


MODELLING NGC 1365

We make use of REFLIONX (Ross & Fabian, 2005) to construct a model based on disc reflection, including:

A powerlaw continuum

Reflection from a partially ionised accretion disc

Neutral absorption local to the source

Neutral reflection from more distant material

Four narrow absorption lines


NGC 1365

χ2υ = 278/268


NGC 1365

This model is physically very similar to that used in Risaliti, Miniutti, et al. 2009.

We obtain similar results, e.g.

Our reflection model reproduces the high energy emission.

This is still consistent with the absorption variability interpretation proposed in Risaliti, Miniutti, et al. 2009.

Iron is over-abundant (~3 times solar) Most of the emission comes from within a few R

G


MODELLING 1H 0419-577

Again, we construct a disc reflection model including:

Following the work of Fabian et al. (2005), we split the disc into an inner and outer region:

The intrinsic powerlaw continuum Reflection from a partially ionised disc


outer

inner

q

q

r

r

r router

inner

outbr

brin

RrR

RrR

- emissivity - ionisation

1H 0419-577

χ2υ = 405/432


Disc Reflection

1H 0419-577

• We find the source to be in a high flux state, following the definitions of Fabian et al. (2005).

• The low reflection fraction of ~0.3 is consistent with their light bending interpretation.

• Most of the emission comes from within a few RG; rotating black hole?

• The high energy emission is reproduced.


SUMMARY

We have constructed disc reflection models for the spectra of NGC 1365 and 1H 0419-577.

They work! Partially covering, Compton thick absorbers are not required.

Our model for NGC 1365 remains consistent with the variable absorption interpretation of Risaliti, Miniutti, et al. 2009.

1H 0419-577 continues to behave as expected in the light bending interpretation of Fabian, et al. 2005.


The High Energy Emission of NGC 1365 and 1H 0419-577

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