The broadband spectral analysis of 4U 1702-429 using XMM-Newton and BeppoSAX data. (arXiv:1811.10922v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Mazzola_S/0/1/0/all/0/1">S.M. Mazzola</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Iaria_R/0/1/0/all/0/1">R. Iaria</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Salvo_T/0/1/0/all/0/1">T. Di Salvo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Santo_M/0/1/0/all/0/1">M. Del Santo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sanna_A/0/1/0/all/0/1">A. Sanna</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gambino_A/0/1/0/all/0/1">A.F. Gambino</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Riggio_A/0/1/0/all/0/1">A. Riggio</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Segreto_A/0/1/0/all/0/1">A. Segreto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Burderi_L/0/1/0/all/0/1">L. Burderi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Santangelo_A/0/1/0/all/0/1">A. Santangelo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+DAmico_N/0/1/0/all/0/1">N. D'Amico</a>
Most of the X-ray binary systems containing neutron stars classified as Atoll
sources show two different spectral states, called soft and hard. Moreover, a
large number of these systems show a reflection component relativistically
smeared in their spectra, which gives information on the innermost region of
the system. Our aim is to investigate the poorly studied broadband spectrum of
the low mass X-ray binary system 4U 1702-429, which was recently analysed
combining XMM-Newton and INTEGRAL data. The peculiar value of the reflection
fraction brought us to analyse further broadband spectra of 4U 1702-429. We
re-analysed the spectrum of the XMM-Newton/INTEGRAL observation of 4U 1702-429
in the 0.3-60 keV energy range and we extracted three 0.1-100 keV spectra of
the source analysing three observations collected with the BeppoSAX satellite.
We find that the XMM-Newton/INTEGRAL spectrum is well fitted using a model
composed of a disc blackbody plus a Comptonised component and a smeared
reflection component. We used the same spectral model for the BeppoSAX spectra,
finding out that the addition of a smeared reflection component is
statistically significant. The best-fit values of the parameters are compatible
to each other for the BeppoSAX spectra. We find that the reflection fraction is
$0.05^{+0.03}_{-0.01}$ for the XMM-Newton/INTEGRAL spectrum and between 0.15
and 0.4 for BeppoSAX ones. The relative reflection fraction and the ionisation
parameter are incompatible between the XMM-Newton/INTEGRAL and the BeppoSAX
observations and the characteristics of the Comptonising corona suggest that
the source was in a soft state in the former observation and in a hard state in
the latter.
Most of the X-ray binary systems containing neutron stars classified as Atoll
sources show two different spectral states, called soft and hard. Moreover, a
large number of these systems show a reflection component relativistically
smeared in their spectra, which gives information on the innermost region of
the system. Our aim is to investigate the poorly studied broadband spectrum of
the low mass X-ray binary system 4U 1702-429, which was recently analysed
combining XMM-Newton and INTEGRAL data. The peculiar value of the reflection
fraction brought us to analyse further broadband spectra of 4U 1702-429. We
re-analysed the spectrum of the XMM-Newton/INTEGRAL observation of 4U 1702-429
in the 0.3-60 keV energy range and we extracted three 0.1-100 keV spectra of
the source analysing three observations collected with the BeppoSAX satellite.
We find that the XMM-Newton/INTEGRAL spectrum is well fitted using a model
composed of a disc blackbody plus a Comptonised component and a smeared
reflection component. We used the same spectral model for the BeppoSAX spectra,
finding out that the addition of a smeared reflection component is
statistically significant. The best-fit values of the parameters are compatible
to each other for the BeppoSAX spectra. We find that the reflection fraction is
$0.05^{+0.03}_{-0.01}$ for the XMM-Newton/INTEGRAL spectrum and between 0.15
and 0.4 for BeppoSAX ones. The relative reflection fraction and the ionisation
parameter are incompatible between the XMM-Newton/INTEGRAL and the BeppoSAX
observations and the characteristics of the Comptonising corona suggest that
the source was in a soft state in the former observation and in a hard state in
the latter.
http://arxiv.org/icons/sfx.gif
