your ID: 0302 
First Name: Anabela 
Last Name: Gon?alves 
Affiliation: Paris Observatory & Lisbon Observatory 

1. (preferred communication: oral) 
========================================== 
Title: New X-ray plasma diagnostics for photoionized 
media in pressure equilibrium 
Authors: A. C. Gon?alves et al. 
Topic:  4 Winds, outflows, absorbers 

Abstract:
Thick ionized media in pressure equilibrium display 
multiple zones of different density, temperature, 
and ionization; such stratified media can be used 
in the modelling of the Warm Absorber in Active 
Galactic Nuclei, X-ray binaries, or Ultraluminous 
X-ray sources. Despite their multiple applications, 
such models are seldon used, mainly because they 
require very sensitive and time-consuming computations. 
The photoionization code TITAN, developed by our team, 
allows for the treatment of the ionized gas in constant 
gas pressure, or total (gas+radiation) pressure. It 
computes the full transfer for the continuum and the 
lines, and accounts for the thermal instabilities in 
pressure equilibrium media, providing throughout 
calculations for the hot and cold stable solutions. 

Bearing in mind the case of thick, stratified media 
in pressure equilibrium, we have used the TITAN code 
to compute a set of photoionization models covering 
a wide range of parameters. We have conducted a systematic 
study of the influence of these parameters on the 
X-ray plasma diagnostics based on H- and He-like species, 
and compared their behaviour with the currently available 
diagnostics, designed for the more restricted case of 
constant density media. Here, we present our main 
conclusions, as well as the new X-ray plasma diagnostics 
for ionized media in pressure equilibrium. 

2. (preferred communication: oral) 
========================================== 
Title: ULXs and IMBHs: the answer is blowing in 
the wind 
Authors: A. C. Gon?alves & R. Soria 
Topic: 1 Black holes 

Abstract:
It was suggested that phenomenological power-law plus 
cool disc-blackbody models represent the simplest, most 
robust interpretation of the X-ray spectra of bright 
ultraluminous X-ray sources (ULXs); this has been taken 
as evidence for the presence of intermediate-mass black 
holes (IMBHs) in those sources. We assess this claim by 
comparing the cool disc-blackbody model with a range 
of other models. 

Using the XMM-Newton/EPIC spectra of two ULXs in 
Holmberg II and NGC 4559 as examples, we show that 
ULX spectra can be fitted equally well by alternative 
models, turning a soft excess into a soft deficit. 
We thus propose a more complex physical model, based 
on a power-law component slightly modified at various 
energies by smeared emission and absorption lines 
from highly-ionized, fast-moving gas. We conclude 
that the presence of a soft excess or a soft deficit depends 
on the energy range over which we choose to fit the "true" 
power-law continuum, and that the observed deviations from 
such a continuum (usually modelled by disc-blackbody components) 
should not be taken as evidence for accretion disc emission, 
nor used to infer BH masses. Finally, we speculate that bright 
ULXs could be in a spectral state similar to, or an extension 
of the steep-power-law state of Galactic Black Hole candidates, 
in which the disc is completely comptonized and not directly 
detectable, and the power-law emission may be modified by the 
surrounding, fast-moving, ionized gas.