The role of complex ionized absorber in the soft X-ray spectra of Intermediate Polars. (arXiv:2107.05636v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Islam_N/0/1/0/all/0/1">Nazma Islam</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mukai_K/0/1/0/all/0/1">Koji Mukai</a>
In magnetic Cataclysmic Variables (mCVs), X-ray radiation originates from the
shock heated multi-temperature plasma in the post-shock region near the white
dwarf surface. These X-rays are modified by a complex distribution of absorbers
in the pre-shock region. The presence of photo-ionized lines and warm absorber
features in the soft X-ray spectra of these mCVs suggests that these absorbers
are ionized. We developed the ionized complex absorber model zxipab, which is
represented by a power-law distribution of ionized absorbers in the pre-shock
flow. Using the ionized absorber model zxipab along with a cooling flow model
and a reflection component, we model the broadband Chandra/HETG and NuSTAR
spectra of two IPs: NY Lup and V1223 Sgr. We find that this model describes
well many of the H and He like emission lines from medium Z elements, which
arises from the collisionally excited plasma. However the model fails to
account for some of the He like triplets from medium Z elements, which points
towards its photo-ionization origin. We do not find a compelling evidence for a
blackbody component to model the soft excess seen in the residuals of the
Chandra/HETG spectra, which could be due to the uncertainties in estimation of
the interstellar absorption of these sources using Chandra/HETG data and/or
excess fluxes seen in some photo-ionized emission lines which are not accounted
by the cooling flow model. We describe the implications of this model with
respect to the geometry of the pre-shock region in these two IPs.
In magnetic Cataclysmic Variables (mCVs), X-ray radiation originates from the
shock heated multi-temperature plasma in the post-shock region near the white
dwarf surface. These X-rays are modified by a complex distribution of absorbers
in the pre-shock region. The presence of photo-ionized lines and warm absorber
features in the soft X-ray spectra of these mCVs suggests that these absorbers
are ionized. We developed the ionized complex absorber model zxipab, which is
represented by a power-law distribution of ionized absorbers in the pre-shock
flow. Using the ionized absorber model zxipab along with a cooling flow model
and a reflection component, we model the broadband Chandra/HETG and NuSTAR
spectra of two IPs: NY Lup and V1223 Sgr. We find that this model describes
well many of the H and He like emission lines from medium Z elements, which
arises from the collisionally excited plasma. However the model fails to
account for some of the He like triplets from medium Z elements, which points
towards its photo-ionization origin. We do not find a compelling evidence for a
blackbody component to model the soft excess seen in the residuals of the
Chandra/HETG spectra, which could be due to the uncertainties in estimation of
the interstellar absorption of these sources using Chandra/HETG data and/or
excess fluxes seen in some photo-ionized emission lines which are not accounted
by the cooling flow model. We describe the implications of this model with
respect to the geometry of the pre-shock region in these two IPs.
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