# An X-ray spectral study of the origin of reflection features in bare Seyfert
1 galaxy ESO 511–G030

Ritesh Ghosh Visva-Bharati University, Santiniketan, Bolpur 731235, West
Bengal, India.  Sibasish Laha Astroparticle physics laboratory, NASA Goddard
Space Flight Center,Greenbelt, MD 20771, USA.  Center for Space Science and
Technology, University of Maryland Baltimore County, 1000 Hilltop Circle,
Baltimore, MD 21250, USA. ritesh ghosh<EMAIL_ADDRESS><EMAIL_ADDRESS>
###### Abstract

The reprocessed X-ray emission from Active Galactic Nuclei (AGN) is an
important diagnostic tool to study the dynamics and geometry of the matter
surrounding the supermassive black holes (SMBHs). We present a broadband
(optical-UV to hard X-ray) spectral study of the bare Seyfert 1 galaxy, ESO
511–G030, using multi-epoch Suzaku and XMM-Newton data from 2012 and 2007
respectively. The broadband spectra of ESO 511–G030 exhibit a UV bump, a
prominent soft-excess below $2\rm\,\,{\rm keV}$, a relatively broad
($\sigma=0.08-0.14\rm\,\,{\rm keV}$) Fe emission line at $6.4\rm\,\,{\rm keV}$
and a weak Compton hump at E$>10\rm\,\,{\rm keV}$. The soft X-ray excess in
ESO 511–G030 can be described either as the thermal Comptonization of disk
seed photons by a warm ($0.40^{+0.02}_{-0.02}\rm\,\,{\rm keV}$), optically
thick ($\tau=12.7^{+0.5}_{-0.4}$) and compact ($<15\rm r_{g}$) corona or as
the blurred reflection from an untruncated and moderate to highly ionized
accretion disk. However, for the blurred reflection, the model requires some
extreme configuration of the disk and corona. Both these models prefer a
rapidly spinning black hole ($a>0.78$) and a compact corona, indicating a
relativistic origin of the broad Fe emission line. We found an inner disk
temperature of $\sim 2-3\,{\rm\,eV}$ that characterises the UV bump and the
SMBH accretes at a sub-Eddington rate ($\lambda_{\rm\,Edd}=0.004-0.008$).

galaxies: Seyfert, X-rays: galaxies, quasars: individual: ESO 511–G030

††journal: ApJ††software: HEAsoft (v6.27.2; HEASARC 2014), SAS (v18.0.0;
Gabriel et al. (2004)), XSPEC (v12.11.0m; Arnaud (1996))

##  1 INTRODUCTION

Active Galactic Nuclei (AGNs) are the most powerful emitters in the Universe.
The accretion of matter onto supermassive black holes (SMBHs) are the main
energy source of this huge emission (Zel’dovich, 1964; Lynden-Bell, 1969). The
accreted matter loses angular momentum and forms a disk-like structure, the
simplest theoretical description of which is an optically thick but
geometrically thin accretion disk (Shakura & Sunyaev, 1973). Thermal emission
from this disk mostly emits in the ultraviolet (UV) band, extending to soft
X-rays. The seed UV photons are Compton upscattered by an optically thin and
hot corona (Shakura & Sunyaev, 1973; Haardt & Maraschi, 1993), around the
central SMBH, and produces a power-law spectrum, that dominates the X-ray
continuum in AGNs. A part of the coronal emission illuminates the accretion
disk and produces reflection features, such as Fe Kα emission around
$6.4\rm\,\,{\rm keV}$ and the Compton hump above $10\rm\,\,{\rm keV}$.
Depending on the ionization state of the accretion disk (Ross & Fabian, 2005;
García & Kallman, 2010) and the proximity of the SMBH, the reflection
component can be blurred and distorted by relativistic effects (Laor, 1991;
Crummy et al., 2006) if originated close to the SMBH; or it can be cold and
neutral if reflected farther from the black hole in the outer part of the disk
and the torus. The presence of broad and/or narrow Fe emission line in the AGN
X-ray spectra generally depicts this idea. In case of Seyfert 1s, apart from
the primary powerlaw component and the Fe emission line, a soft-excess
component (Arnaud et al., 1985; Singh et al., 1985) is also observed below
$2\rm\,\,{\rm keV}$. The origin of this excess is still debated. Current
studies usually tend to favour either the blurred and ionized disk reflection
or the intrinsic disk Comptonization of disk photons. These reflection
features originate within a few gravitational radii from the SMBH and hence
serve as an important probe of the inner extent of the accretion disk and the
black hole spin (Wilkins & Fabian, 2011).

However, in several cases, these spectral features are modified by the line of
sight absorption due to neutral or ionised clouds. Hence, ‘bare’ AGNs, showing
no signs of absorption, are crucial to study the emission from the spatially
unresolved central region. Notable examples of such sources are Fairall 9
(Gondoin et al., 2001; Schmoll et al., 2009; Emmanoulopoulos et al., 2011),
Ark 120 (Vaughan et al., 2004; Nardini et al., 2011) and Mrk 509 (García et
al., 2019). Previous studies of these sources reveal prominent reflection
features in the observed X-ray spectra in the form of soft excess and Fe line
complex along with the presence of occasional Compton hump. A reflection-based
analysis of a sample of 25 bare AGNs by (Walton et al., 2013) suggests a
general preference for rapidly rotating black holes of bare AGNs. In our work,
we aim to study the broadband X-ray spectra of a bare AGN to rigorously test
the reflection interpretation and subsequently unravel the disk, corona and
the central engine properties.

ESO 511–G030 is a bare AGN as have been found by Tombesi et al. (2010); Winter
et al. (2012); Laha et al. (2014) and a prime candidate for fulfilling this
role due to its prominent reflection features. It is a nearby ($z=0.0224$)
Seyfert 1 galaxy and also one of the X-ray brightest bare Seyferts featured in
the Swift 58 month BAT catalogue (Winter et al., 2012). ESO 511–G030 was
observed only once by the XMM-Newton in 2007 and previous studies revealed the
presence of a soft excess and a Fe emission line around $6.4\rm\,\,{\rm keV}$
(Tombesi et al., 2010; Winter et al., 2012; Laha et al., 2014) in the source
spectra. Tombesi et al. (2010); Laha et al. (2014) found the presence of a
broad Fe K line emission at $6.4\rm\,\,{\rm keV}$ with an equivalent width of
$\sigma=100\pm 15\,{\rm\,eV}$. Using the same observation, a similar study
carried out by Winter et al. (2012), showed the presence of a narrow Fe
emission line ($\sigma=39^{+8}_{-8}$) in the source spectrum. Fukazawa et al.
(2011) studied the source using two Suzaku observations and found the presence
of narrow Fe K emission lines. They studied the Fe line flux variability of a
sample of sources including ESO 511–G030 and suggested that X-ray reflection
by a torus is the main origin of this narrow Fe K emission. Previous studies
of ESO 511-G030 mentioned here have primarily focused on understanding the
details of the warm absorber and high-velocity outflows. In this work we
address the following science questions: 1. The nature and origin of the Fe
line emission in the source spectra 2. Detection or nondetection of the soft
excess and the Compton hump and finally 3. If we do detect a broad Fe line,
can we constrain the black hole spin? We used the multi-epoch broadband
($0.001-50\rm\,\,{\rm keV}$) spectra of ESO 511-G030 using the XMM-Newton and
Suzaku observations. We have also used OM data from XMM-Newton to constrain
the UV bump, necessary to investigate the accretion disk and black hole
properties with physically motivated models. Throughout this paper, we assumed
a cosmology with $H_{0}=71\rm\,\,{\rm km\,s^{-1}}\,{\rm
Mpc}^{-1},\Omega_{\Lambda}=0.73$ and $\Omega_{M}=0.27$. The paper is organised
as follows: Section 2 describes the observation and data reduction techniques.
The steps taken in the spectral analysis are discussed in Section 3. Section 4
discusses the results followed by conclusions in Section 5.

##  2 Observation and data reduction

ESO 511–G030 was observed only once by XMM-Newton in 2007 August 5 and twice
by Suzaku in 2012 July 22 and in 2012 August 17. The details of the
observations and the short notation of the observation ids are mentioned in
Table 1. We processed the EPIC-pn and OM data using V18.0.0 of the Science
Analysis Software (SAS) (Gabriel et al., 2004) with the task epchain and
omichain respectively and filtered them using the standard filtering
criterion. We used the latest calibration database available at that time. The
EPIC-pn data was preferred due to its higher signal to noise ratio compared to
MOS. We checked the background rate above $10\rm\,\,{\rm keV}$ for any flaring
particle background and used a rate cutoff of $<1\,\rm cts^{-1}$ to create the
good time intervals. To extract the source spectrum and light curve, we
selected a circular region of 40 arcsec, centred on the centroid of the
source. For the background spectrum and light curve, we chose nearby circular
regions, located on the same CCD, that are free of any sources. The EVSELECT
task was used to select single and double events for EPIC-pn ($PATTERN<=4$,
$FLAG==0$) source event lists. We created the time-averaged source +
background, the background spectra and the corresponding response matrix
function (RMF) and auxiliary response function (ARF) for each observation
using the xmmselect command in SAS. We checked for pile up in the XMM-Newton
source spectra using the command epatplot and found that observation (obs1
from now on) is not piled up. The XMM-Newton spectra were grouped by a minimum
of 50 counts per channel and a maximum of three resolution elements using the
command specgroup. For the OM data, we obtained the count rates in four active
filters (B, UVW1, UVM2 and UVW2) by specifying the RA and Dec of the source in
the source list file obtained by the omichain task. The om2pha task was used
to produce the necessary files for OM photometric data to be analysed
simultaneously with EPIC-pn in XSPEC.

ESO 511–G030 was observed twice by Suzaku on 22nd July and 17th August 2012
(See Table 1). The three X-ray Imaging Spectrometer (XIS) (Koyama et al.,
2007) along with the Hard X-ray Detector (HXD) (Takahashi et al., 2007) cover
the broad energy band of $0.2-50\rm\,\,{\rm keV}$. In both observations (from
now on obs2 and obs3 respectively), all the data were obtained in standard XIS
($3\times 3$ and $5\times 5$) and HXD data modes. The data reduction technique
of XIS and HXD-PIN is the same as Ghosh et al. (2018), following the standard
Suzaku data reduction. We used HEASOFT(v6.27.2; HEASARC 2014), software and
the recent calibration files to reprocess the Suzaku data. For the non-imaging
HXD/PIN data, we used the appropriate tuned background files provided by the
Suzaku team and available at the HEASARC website. The XIS front-illuminated
spectra were coadded to enhance the signal to noise ratio. We grouped the XIS
spectral data off to a minimum of 200 and 100 counts in each energy bin for
obs1 and obs2 respectively. We also grouped the PIN data using the command
grppha in the HEASOFT software to produce $\sim 30$ energy bins with more than
20 counts per bin in the source spectra.

##  3 Data Analysis and spectral fitting

We used XSPEC (Arnaud, 1996) version 12.11.0m to analyse all the data sets and
all errors quoted on the fitted parameters reflect the 90 per cent confidence
interval corresponding to $\,\Delta\chi^{2}=2.7$ (Lampton et al., 1976). We
excluded the XIS data in the $1.7-2.3\rm\,\,{\rm keV}$ from our spectral
analysis due to calibration uncertainties. We used tbabs model to estimate the
effect of Galactic absorption and set the scattering cross-section to Verns
and abundances to Wilms values. In all our spectral fitting, we adopted the
Galactic column density value of $\rm N_{H}=4.34\times 10^{20}\rm cm^{-2}$
(Dickey & Lockman, 1990).

We started our analysis with a preliminary look at the spectra of the source.
We used an absorbed power-law model in the $4-5\rm\,\,{\rm keV}$ energy band
and when extrapolated to the rest of the X-ray band revealed a prominent soft
excess (below $2\rm\,\,{\rm keV}$), a Fe line complex at $6-7\rm\,\,{\rm keV}$
for all three observations. We did not find any significant excess above
$10\rm\,\,{\rm keV}$ in any of the two Suzaku HXD-PIN data sets (See Fig. 1).
To address our science goals, we organize the spectral analysis of multi-epoch
broadband data, into three parts: above $3\rm\,\,{\rm keV}$, the full X-ray
band and the joint X-ray and UV. Here, the detailed analysis of the above
$3\rm\,\,{\rm keV}$ energy band will help us reveal the true nature of the Fe
emission line. On the other hand, the study of full X-ray and joint X-ray plus
UV data of ESO 511–G030, with physically motivated models, will help us
investigate the nature of accretion disk and black hole properties and the
role they play in the origin of the soft excess. The latest XSPEC version used
here provides us with the best-fit statistics of individual data sets during
simultaneous model fitting. Hence, a simultaneous multi-epoch spectral fit of
XMM-Newton and Suzaku spectra was carried out in all three cases.

###  3.1 Investigating the Fe emission line

To investigate the excess emission in the $6-7\rm\,\,{\rm keV}$, we first
introduced a narrow Gaussian to the absorbed powerlaw model. An energy-
independent multiplicative factor was used to account for the relative
normalization between different instruments of Suzaku. Assuming a bare nature
of the source we did not include any neutral or partially ionised absorber
model to the set of models used here. In XSPEC the model reads as
constant$\times$ tbabs $\times$ (po$+$ zgauss). The best-fit statistics for
this set of models is $\,\rm\chi^{2}/dof=1587/1414$. The line energy is
consistent with $6.4\rm\,\,{\rm keV}$ for all three observations and the
equivalent width ranges between $62\,{\rm\,eV}$ to $94\,{\rm\,eV}$. We found
the source frame line width $\sigma=0.08-0.14\rm\,\,{\rm keV}$ between
observations, which indicates the presence of a broad Fe emission line in the
source spectra. The broad Gaussian if replaced with a narrow Gaussian line
($\sigma=0.01\rm\,\,{\rm keV}$) provides a relatively poor fit statistics to
the data sets ($\,\rm\chi^{2}/dof=1603/1417$). Next, we replaced the broad
Gaussian line with a more realistic broad Fe line profile diskline, (Fabian et
al., 1989), which resulted in a similar fit statistics
($\,\rm\chi^{2}/dof=1587/1414$). In the diskline model, the inner and outer
radius of the disk was fixed at $r_{\rm in}=6r_{\rm g}$ and $r_{\rm
out}=400r_{\rm g}$ respectively for all three observations. The power law
dependence of emissivity ($\beta$), the line energy and the model
normalizations are made free for obs 1 and obs2. The inclination angle is tied
between observaions. The best-fit line energy is consistent between
observations with a value of 6.42 keV. The high value of emissivity profile
($\rm q=0.9-9.1$) indicates a large amount of coronal radiation intercepts the
disk.

Alternatively, a partial covering absorber model (neutral or ionized) may
mimic the red wing of the broad Fe emission line in the broad-band X-ray
spectrum. The partial covering model with neutral or ionized absorption
(zpcfabs or zxipcf) when multiplied with the absorbed (Galactic) power-law
model resulted in a poor statistics for all the three data sets
($\,\rm\chi^{2}/dof=1868/1421$ and $\,\rm\chi^{2}/dof=1873/1422$ for zpcfabs
or zxipcf respectively). See Table 2 for the comparison of a different set of
models used to fit the Fe line emission. Our analysis indicates the presence
of a broad Fe K$\alpha$ emission line in the X-ray spectra of all three
observations. Next, we study the full X-ray band to further characterize the
reflection features.

###  3.2 The full X-ray band

We initially analysed the broadband X-ray data with a phenomenological set of
models to test the presence and strength of reflection features in the source
spectra. The baseline phenomenological model used here includes a neutral
Galactic absorption (tbabs), a multiple blackbody component to model the soft
excess (diskbb, Mitsuda et al., 1984) and the coronal emission described by a
power-law. In addition, we used a diskline model to describe excess emission
at around $6.4\rm\,\,{\rm keV}$. An energy-independent multiplicative factor
was introduced to account for the relative normalization of different XIS and
PIN instruments. In XSPEC notation, the phenomenological model reads as
constant$\times$ tbabs$\times$ (powerlaw$+$diskbb$+$diskline). Addition of a
ztbabs model did not improve the fit statistics and we conclude that all three
observations are free from any intrinsic neutral absorption of the host
galaxy. We included the pexrav model to check for the reflection component
from the neutral medium which contributes to the Compton hump. The XMM-Newton
EPIC-pn data ($<10\rm\,\,{\rm keV}$) is insufficient to constrain the pexrav
reflection parameters and hence tied with the Suzaku observation (obs2) with
longer exposure. We found a significant improvement in the fit statistics upon
the addition of pexrav ($\,\Delta\chi^{2}\sim 72$ for 4 dof) indicating the
presence of neutral reflection component in the hard X-ray band above
$10\rm\,\,{\rm keV}$. The phenomenological model provides a satisfactory
description to the two Suzaku as well as XMM-Newton spectra. The best-fit
parameter values obtained using the phenomenological models are marginally
consistent between observations and quoted in Table 3. We also quoted the
improvement in statistics ($\rm\,\Delta\chi^{2}/dof$) for each spectrum upon
the addition of different model components to determine the statistical
significance of the model (See Table 3). The line energy of the Fe emission is
consistent with $6.4\rm\,\,{\rm keV}$ for all three observations. Our results
indicate that a prominent soft excess and a broad Fe Kα emission line is
present in all the observations that are usually considered as signs of
relativistic reflection from the disk.

However, the origin of soft excess is still debated and apart from the
relativistic reflection from disk, intrinsic disk Comptonization has also been
found to be a viable physical model in other Seyfert 1 galaxies. In our work,
we used two sets of physical models to describe both the soft excess and the
Fe emission line in the Suzaku and XMM-Newton X-ray spectra of ESO 511–G030.
In XSPEC, our first set of physical models reads as constant $\times$ tbabs
$\times$ (relxill$+$MyTorus). Here, the relxill model, version 1.3.7, (García
et al., 2014) describes the soft X-ray excess, the power-law continuum, the
broad Fe K$\alpha$ emission line and the reflection of primary hard X-ray
photons off an ionized accretion disk, on the other hand, the Compton
reflection of hard X-ray photons off cold, neutral material is modelled with
MYTorus. The MYTorus model comprised of three components: first, the torus-
absorbed primary power-law, second, the scattered emission (MYTorusS) due to
the reflection of primary hard X-ray photons from the torus and third, the
iron FeKα and K${\beta}$ lines (MYTorusL), which are assumed to arise due to
the reflection by the torus. ESO 511–G030 is a type-1 AGN hence we do not
expect any obscuration due to torus along the line of sight. We have used only
MYTorusS and the MYTorusL component in our spectral fitting and tied their
column densities together. The column density of MYTorus gives a value in an
equatorial direction of a dusty torus, so a Compton-thick value is expected
even in type 1 sources (Yaqoob et al., 2016; Laha et al., 2019; Ghosh & Laha,
2020). When made free, the MYTorus column density pegged at $10^{25}\rm
cm^{-2}$ and we got a lower limit of $2.9\times 10^{24}\rm cm^{-2}$. Hence, we
froze the MYTorus column density to a value of $10^{25}\rm cm^{-2}$, assuming
that a Compton thick torus is responsible for this emission. We also fixed the
inclination angle between the torus polar axis and the observer’s line of
sight to 45 degrees for both sets of physical models. The photon index of the
MYTorus model was tied with that of the photon index of the primary continuum
of relxill model. In the relxill model, the primary hard X-ray emission from
corona illuminates the accretion disk and produces fluorescence emission
lines. These fluorescence lines get blurred and distorted due to extreme
gravity near the central supermassive black hole and produce the soft excess.
The transition between Newtonian and relativistic geometry is marked by a
breaking radius $\rm r_{br}$. In our work, the emissivity index of reflection
from the disk outside $\rm r_{br}$ (q2) is fixed at 3, as in Newtonian
geometry, for a point source, the emissivity at a large radius out from the
source has a form $\rm r^{-3}$. The emissivity index inside $\rm r_{br}$ falls
under the relativistic high-gravity regime and calculations (Dabrowski &
Lasenby, 2001; Miniutti et al., 2003; Wilkins & Fabian, 2011) suggest a very
steeply falling profile in the inner regions of the disk. Hence, we made the
emissivity index of the inner part (q1) of the accretion disk inside $\rm
r_{br}$, free to vary in between $3<\rm q1<10$.

During our simultaneous analysis of joint XMM-Newton and Suzaku data sets, the
parameters that are unlikely to change within human timescale, e.g., the black
hole spin and the inclination angle, were tied between all observations. Apart
from the power-law photon index, normalization and the reflection fraction
(R), all other parameters were tied between the two Suzaku observations. The
MYTorus model requires a hard X-ray spectrum to constrain its parameters. Due
to the absence of $>10\rm\,\,{\rm keV}$ spectrum in XMM-Newton observation,
the MYTorus parameters were tied with best-fit parameter values of obs2. This
set of physical models produced a satisfactory fit with fit statistics
$\,\rm\chi^{2}/dof=3431/2981$ however we observed some excess in the residual
at $\sim 0.5$ and $0.9\rm\,\,{\rm keV}$. Addition of two narrow Gaussian line
profile to the model yielded an improved fit ($\,\rm\chi^{2}/dof=3345/2976$).
We estimated the high energy cutoff of the primary power-law component using
the Suzaku observation with the longest exposure (obs1). We found a lower
limit to the high energy cutoff with $\rm E_{c}>297\rm\,\,{\rm keV}$. We tied
this value for all other observations. A rapidly spinning black hole ($>0.98$)
is required by the model to fit the X-ray spectra. We carried out a test to
find out if the black hole is indeed maximally spinning. First, we froze the
spin parameter to zero and kept the inner radius ($\rm r_{in}$) of the relxill
model fixed to the inner circular stable orbit for a non-rotating black hole
($\rm r_{in}=6\rm r_{g}$) and fitted the data sets. Next, we froze spin to
0.998 and fixed the $\rm r_{in}$ value to that of a maximally spinning black
hole ($\rm r_{in}=1.24\rm r_{g}$). We found that the maximally spinning
scenario provides a significantly better fit statistics
($\,\Delta\chi^{2}=501$). Following this result, we fixed the inner radius we
fixed the inner radius of the disk at $\rm r_{in}=1.24\rm r_{g}$ throughout
the rest of the fit and allowed the spin parameter to vary freely. We found
the iron abundance of the material in the accretion disk to be significantly
lower than the solar value ($\rm A_{Fe}<0.7$) for the two Suzaku observations.
The best-fit reflection fraction (R) ranges between $\rm R=0.5-5.3$ for the
three observations. The best-fitting model parameters along with the best-
fitting statistics for each observation are quoted in Table 4.

We have also tested other flavours of relxill, such as relxillD and relxilllP.
The model relxillD allows a higher density for the accretion disk (between
$\log N/\rm cm^{-3}=15.3$ to $\log N/\rm cm^{-3}=18$) and the model relxilllP
assumes a lamp post geometry and determines the variation in the position of
the hard X-ray emitter. Both these models produced a relatively poor
statistics ($\,\rm\chi^{2}/dof=3434/2973$ for relxillD and
$\,\rm\chi^{2}/dof=3469/2976$ for relxilllP respectively) compared to relxill,
for all the observations and no significant variation either in the disk
density or in the position of the hard X-ray emitter was found.

For the second set of physical models, we use intrinsic thermal Comptonization
from a warm corona (optxagnf). In the optxagnf model, thermal comptonization
of disk photons by a warm ($\rm T\sim 0.5-1\rm\,\,{\rm keV}$) and optically
thick ($\tau\sim 10-20$) corona (Magdziarz et al., 1998; Done et al., 2012),
that lies in the inner part ($10-20\rm r_{g}$) of the accretion disk, produces
the soft excess. The gravitational energy released in the accretion process
fuels the disk emission in UV, the soft X-ray excess and the power-law
emission. The model normalization flux is determined by the source Eddington
rate, the black hole mass, the black hole spin and the luminosity distance.
Hence in our analysis, we froze this value at unity. The hard excess emission,
in this set of models, arises exclusively due to neutral Compton reflection
from the torus. In XSPEC notation, the model reads as (constant $\times$
tbabs$\times$(optxagnf + MYTorus)). We used a black hole mass of $\sim
4.57\times 10^{8}M_{\odot}$, adopted from Ponti et al. (2012), who derived it
using X-ray variability of the source. In our simultaneous fit of Suzaku and
XMM-Newton, apart from the black hole spin, all other optxagnf model
parameters were made free to vary. On the other hand, for the two Suzaku
observations, except for the Eddington rate, photon index and the parameter
$\rm f_{pl}$, that determines the fraction of powerlaw emitted as soft excess,
all other parameters were tied between observations. This set of physical
models produced a poor fit statistics ($\,\rm\chi^{2}/dof=3411/2992$) compared
to our first set of models, however, we observed similar excess emission in
the residual at $\sim 0.5\rm\,\,{\rm keV}$ and $\sim 0.9\rm\,\,{\rm keV}$.
Addition of two Gaussian line profile to the set of models provided similar
fit statistics ($\,\rm\chi^{2}/dof=3351/2987$) compared to the reflection
model relxill. All three observation show sub-Eddington accretion rate ($\sim
0.004-0.008$) and infer a maximally spinning black hole ($>0.98$). Table 5
includes the best-fitting parameters obtained using this model. Next, we
included the OM data from the XMM-Newton and tried to get a better constrain
on the optxagnf model parameters.

###  3.3 The joint UV and X-ray band

The thermal Comptonization model uses disk photons to produce the powerlaw
spectra and the soft excess. Therefore, the UV bump is required to constrain
the optxagnf parameters. In this section, we re-fit the X-ray data along with
the simultaneously obtained UV spectra to constrain the model parameters.

We used the optical/UV fluxes in four bands (B, W1, W2 and M2) measured with
the XMM-Newton to constrain the thermal emission from the disk. The Galactic
extinction correction was done following (Fitzpatrick, 1999) reddening law
with $\rm R_{v}=3.1$ and is taken into account by the REDDEN model. The
parameter value used here is $\rm E_{(B-V)}=0.056$ (Schlafly & Finkbeiner,
2011). We have added 5 per cent systematic error to the OM fluxes to account
for the host galaxy contamination, the nuclear emission lines and the
intrinsic reddening, which produce a considerable amount of systematic
uncertainty in the measured optical-UV continuum flux. The two sets of
physical models, relxill and optxagnf, were used to jointly fit the OM and
EPIC-pn data of XMM-Newton along with the two Suzaku observations. The best-
fitting parameter values are quoted in Table 5. The model parameters of
relxill and MyTorus were frozen in the joint fit as they were determined by
the X-ray energy band only and we added a diskbb model to fit the OM data. The
model resulted in a fit-statistic of $\,\rm\chi^{2}/dof=3349/3001$. In the
case of optxagnf model, we froze the MyTorus model parameters and allowed
optxagnf model parameters to vary freely. We find that this second set of
physical models yield a marginally poor fit statistics
($\,\rm\chi^{2}/dof=3369/2989$) (See Table 5) compared to the ionized
reflection model nevertheless both provide a satisfactory description to the
broadband optical-UV to hard X-ray data.

Our simultaneous analysis of UV and X-ray data enabled us to get a better
constrain on the warm corona properties, e.g., the electron temperature, the
radius and the opacity(See Table 5). Our results suggest the presence of a
warm ($\rm kT_{e}=0.1-0.5\rm\,\,{\rm keV}$), optically thick ($\tau=8-13$) and
compact ($\rm r_{corona}=5.9-11.8\rm r_{g}$) corona and a maximally rotating
($a>0.98$) black hole. The best-fitting models obtained from the joint fitting
of XMM-Newton and Suzaku are shown in Fig. 3. A detailed discussion of these
results is followed in the next section.

##  4 Results and Discussion

We have extensively studied the broadband optical-UV to hard X-ray
($0.001-50\rm\,\,{\rm keV}$) spectra of Seyfert 1 galaxy ESO 511–G030 using
all the archival data from Suzaku and XMM-Newton. In our work, for the first
time, we have used physically motivated models to describe the observed
reflection features in the source spectra. Our study enabled us to
unambiguously constrain the accretion disk properties and subsequently the
black hole spin. We find that both reflections from an ionized disk and
intrinsic thermal Comptonization describe the soft excess well.

However, the thermal Comptonization model yielded a much better fit statistics
to the optical-UV to hard X-ray source spectra. We measured the
$2-10\rm\,\,{\rm keV}$ unabsorbed luminosity ($\log\rm L_{2-10\rm\,\,{\rm
keV}}$) of the source and found it to be consistent between 2007 and 2012. The
observed values are $43.52\rm\,\,{\rm erg\,s^{-1}}$, $43.50\rm\,\,{\rm
erg\,s^{-1}}$ and $43.66\rm\,\,{\rm erg\,s^{-1}}$ for obs1, obs2 and obs3
respectively. We estimated of the bolometric luminosity of ESO 511–G030
($4.76\times 10^{43}\rm\,\,{\rm erg\,s^{-1}}$), using the following equation:
$\log\kappa_{\rm Lbol}=1.561-1.853\times\alpha_{\rm OX}+1.226\times\alpha_{\rm
OX}^{2}$ (Lusso et al., 2010; Laha et al., 2018). We used the OM flux value of
XMM-Newton observation, the value of $\rm L_{2-10\rm\,\,{\rm keV}}$ and the
$\alpha_{\rm OX}$, where $\alpha_{\rm OX}$ is the power-law slope joining the
$2\rm\,\,{\rm keV}$ and the $2500\rm\AA$ flux. ESO 511–G030 has a black hole
mass of $\sim 4.57\times 10^{8}M_{\odot}$ (Ponti et al., 2012) which implies
an Eddington ratio of $0.002$. This result is in contrast with (Noda & Done,
2018), who studied the changing look AGN MRK 1018 with optxagnf and fixed the
black hole spin value to zero. But in our case, we found a model-dependent
high black hole spin and a strong soft X-ray excess that is present even for a
small fraction (0.4-0.8%) of $\lambda_{\rm\,Edd}$. Our measured Eddington rate
is consistent with the value previously found by Laha et al. (2014),
indicating a steady accretion state in the source during 2007 and 2012. Using
the reflection model we got a lower limit to the high energy cut off value
($\rm E_{c}>297\rm\,\,{\rm keV}$) of the primary power-law component. Below we
discuss the main results investigating the spectral features observed in this
source.

###  4.1 The Fe Kα line and the Compton hump

Previous studies of the X-ray spectra of ESO 511–G030 have mostly revealed the
presence of a relativistically broad Fe emission line. Tombesi et al. (2010);
Laha et al. (2014) studied the 2007 XMM-Newton data and found a broad Fe
emission line at $6.4\rm\,\,{\rm keV}$ with an equivalent width of
$\sigma=100\pm 15\,{\rm\,eV}$. On the other hand, using the same observation,
Winter et al. (2012) studied the X-ray broadband properties and detected the
presence of a narrow Fe emission line ($\sigma=39^{+8}_{-8}$) in the source
spectrum. Fukazawa et al. (2011) studied the source using two Suzaku
observations and found the presence of narrow Fe K lines. In our work, we have
investigated the above $3\rm\,\,{\rm keV}$ energy band with a set of models to
unambiguously determine the nature of the Fe emission line. We found the
presence of a broad Fe emission line at $\sim 6.4\rm\,\,{\rm keV}$ in all the
spectra of ESO 511–G030. The best-fit Fe emission line $\sigma$
($0.08-0.14\rm\,\,{\rm keV}$) and equivalent width ($62-94\,{\rm\,eV}$) are
significantly broad than the equivalent width of typical narrow Fe emission
line found in nearby Seyfert 1 galaxies. The broad Gaussian line profile and
the diskline model provides a better description of the Fe line emission than
other sets of models and indicates the presence of a relativistically-
broadened Fe emission line from an accretion disk around a rotating black
hole. Our broadband spectral modelling of ESO 511-G030 with both set of
physical models favours a rapidly spinning black hole and supports this idea.
In all the observations, the Fe line centroid energy was consistent with
$6.4\rm\,\,{\rm keV}$, which indicates that the iron is neutral or in low
ionization state. The best-fit ionization parameter value of the XMM-Newton
observation ($\log\xi=2.3^{+0.1}_{-0.1}$) supports this idea. However, for the
two Suzaku observations, we got a highly ionized accretion disk
($\log\xi=3.2^{+0.1}_{-0.1}$) compared to obs1. From Fig. 1 we note that the
Compton hump above $10\rm\,\,{\rm keV}$ is relatively weak but the addition of
a pexrav model to the phenomenological set of models did improve the fit-
statistics ($\,\Delta\chi^{2}\sim 72$ for 4 dof) significantly. From Fig. 2 we
find that both neutral and ionised reflection component provides a good
description of the Compton hump. With the current data quality in Suzaku, we
are unable to comprehensively detect or separate out the contributions of the
ionized and neutral reflection components and further deep observations of
Seyfert 1s are required.

###  4.2 The soft excess

Our analysis of the full X-ray band of ESO 511–G030 revealed the presence of a
prominent soft excess below $2\rm\,\,{\rm keV}$ for all three observations. We
investigated the broadband multi-epoch data in detail to identify the disk and
black hole properties responsible for this excess emission. Recent studies
suggest that both relativistic reflection from an ionized accretion disk and
the intrinsic thermal Comptonization of disk photons can successfully describe
the soft excess in Seyfert 1s (Ghosh & Laha, 2020; García et al., 2019;
Waddell et al., 2019; Ehler et al., 2018). These two models assume two very
different geometries and physical properties of the accretion disk and the
corona (e.g., the position, temperature and the opacity). However, it is not
easy to distinguish them on statistical grounds alone and often extreme values
of certain model parameters are used to favour one model over the other. In
some nearby Seyfert 1s, e.g., HE 1143-1810 (Ursini et al., 2020) and Zw
229.015 (Tripathi et al., 2019), the ionized disk reflection model was ruled
out due to the relatively extreme values of the iron abundance, the
inclination angle and reflection fraction, compared to other Seyfert 1s. On
the other hand, in Mrk 478 (Waddell et al., 2019), the flux variability
between data sets was better described by ionised disk reflection, compared to
the thermal Comptonization model.

In our work, we have studied the reflection features observed in the ESO
511–G030 spectra and got comparable fit statistics for both of these physical
models. The soft excess is equally well described by both these models. The
best-fit parameter values obtained for the optxagnf model were in a range
detected in typical Seyfert 1 galaxies (See Table 4) although, we were unable
to constrain the optical depth in obs2 (See Table 5). Similarly, for the
reflection model, some model parameters require extreme values to model the
soft excess and the X-ray energy band. The best-fit photon index $\Gamma$ of
the model relxill ranges between $1.7-2.0$ for all three observations. The
best-fit ionization parameter value of the model ($\log\xi\sim
2-3\rm\,erg\,cm\,s^{-1}$) suggests a transition between moderate to highly
ionized disk between obs1 and obs2 respectively. In the reflection model
relxill, the black hole spin and the inner radius are degenerate and hence
fixing the inner radius to the ISCO provides a better constrain on the spin.
Hence we fixed the inner radius to $1.24\rm r_{g}$ and obtained a maximally
spinning black hole ($\rm a>0.98$). We were able to constrain the inclination
angle parameter and found a best-fit value of $27^{+3}_{-1}$. The iron
abundance of the reflecting medium ($\rm A_{Fe}$) or the disk is marginally
consistent with the solar abundance value for the XMM-Newton observation
however when made free we got an upper limit of $<0.6$ for the two Suzaku
observations. We also found a large variation in the best-fit value of
reflection fraction (R) between the three observations, ranging between 0.5 to
5.3, although consistent with other Seyfert 1s. This value R, determines the
ratio of photons entering the disk to the ones escaping to infinity and
indicate that most of the hard X-ray photons are entering the disk and results
in a highly ionized disk. These results along with the high emissivity index
ranging between $4.6-8.2$ imply that major part of the soft excess has
originated from a region very close to the central supermassive black hole due
to reflection of hard X-ray photons from a highly ionized untruncated
accretion disk. Although very high values of black hole spin and the
reflection fraction or lower iron abundances in the disk are occasionally
reported for AGNs, a corona placed so close to the black hole implies a very
extreme configuration of the accretion disk and the corona.

On the other hand, the intrinsic thermal Comptonization model optxagnf
combined with the neutral reflection from the torus, modelled by MyTorus,
provides a similar fit statistics compared to the ionized reflection. Most of
the best-fit parameter values obtained from the fitting of the full X-ray band
are well constrained and are typical of other Seyfert 1 galaxies (Ghosh &
Laha, 2020; Porquet et al., 2018; Ursini et al., 2020). In this model, the
soft excess originates due to Comptonization of thermal disk photons by a warm
and optically thick corona that covers roughly $5-12\rm r_{g}$ of the inner
accretion disk (Petrucci et al., 2013). However, we note that the accretion
rate in optxagnf is also determined by the outer accretion flow beyond $\rm
r_{corona}$ that contributes primarily in the optical-UV band. This explains
our inability to constrain some of the model parameters e.g., the $\rm
r_{corona}$ and the black hole spin. Hence we discuss the best fit parameter
values obtained from the simultaneous analysis of the optical-UV to hard X-ray
broadband data with optxagnf as they provide us with a more clear view of the
accretion disk and the black hole properties.

###  4.3 The optical-UV to hard X-ray continuum

In the optxagnf model, the gravitational energy released in accretion, powers
three distinct emission components - the UV bump, the soft excess, and the
hard X-ray power law. As expected, optxagnf combined with neutral reflection
from torus yielded better fit statistics (See Table 5) compared to the ionized
reflection model. From the joint fits of all three observations, using the
relxill$+$diskbb model, we find that the disk blackbody has a much colder
temperature of $\rm kT=3.8^{+0.7}_{-1.2}\,{\rm\,eV}$. This value is comparable
with the inner radius temperature, $\sim 2\,{\rm\,eV}$, of the accretion disk
that is accreting at a rate of $\lambda_{\rm\,Edd}=0.004$, obtained for obs1,
using optxagnf model. This best-fitting accretion rate is close to our
estimated value ($\lambda_{\rm\,Edd}=0.002$) obtained using the bolometric
luminosity of ESO 511–G030. The soft excess in XMM-Newton observation is well
described as a warm ($\rm kT=0.4^{+0.02}_{-0.02}\rm\,\,{\rm keV}$) and
optically thick ($\tau=12.7^{+0.5}_{-0.4}$) corona. These values are
marginally consistent with that of obs3. In the case of obs2, we could not
constrain the optical depth ($\tau$). The measured warm-corona radius ($\rm
r_{\rm corona}$) remains nearly consistent between observations with values of
$11.8^{+2.5}_{-1.8}\rm r_{g}$ and $5.9^{+1.9}_{-0.5}\rm r_{g}$ for XMM-Newton
and Suzaku observations respectively and indicates a compact corona. We note
that the optxagnf model, similar to the relxill, favours a maximally rotating
black hole spin to describe the broadband spectra. We could not constrain the
spin parameter in optxagnf and got a lower limit of $>0.98$. We argue that a
highly rotating black hole is required to model the broadband data in both
ionized reflection and thermal Comptonization scenario and the presence of
broad Fe emission line in the spectra further supports the idea of a highly
spinning black hole at the centre of the AGN. The $\rm f_{pl}$ parameter in
the optxagnf model determines the fraction of power below the coronal radius
emitted in the hard comptonisation component. This parameter value is
marginally consistent between the three observations with moderate values of
$\sim 0.6$ and $\sim 0.4$ for XMM-Newton and Suzaku observations respectively.
This implies, in obs1, around 60 per cent of the gravitational energy released
below $12\rm r_{g}$, is emitted as the primary power-law emission with a
photon index $\sim 1.74$ and the rest would help produce the soft excess.
These values are consistent with recent studies found in other local Seyfert
1s (Ghosh & Laha, 2020; Porquet et al., 2019). Hence we conclude that for ESO
511–G030, highly ionized, relativistically blurred reflection from an
untruncated accretion disk and the intrinsic thermal Comptonization of disk
seed photons by a warm and optically thick compact corona, both combined with
the neutral reflection from the torus, provide a good description to the
multi-epoch optical-UV to hard X-ray spectra with parameter values consistent
with other Seyfert 1s.

##  5 Conclusions

We have extensively studied the broadband optical-UV to hard X-ray spectra of
the bare Seyfert 1 galaxy ESO 511–G030 using XMM-Newton and Suzaku multi-epoch
observations and investigated the spectral features observed in the source
with a physically motivated set of models. We list the main conclusions below.

  * •

The optical-UV to hard X-ray spectra of ESO 511–G030 is typical of local
Seyfert galaxies and consists of four components. A UV bump with an inner
radius temperature of $\sim 2-3\,{\rm\,eV}$, a power-law continuum with a
photon index varying between $\Gamma=1.7-2.0$, a prominent soft-excess and a
relatively broad Fe line emission at $\sim 6.4\rm\,\,{\rm keV}$.

  * •

We found that the source is accreting at a sub-Eddington rate
($\lambda_{\rm\,Edd}$ varies within $0.004-0.008$) between 2007 and 2012.

  * •

The soft X-ray excess in ESO 511–G030 can be described either as the thermal
Comptonization of disk seed photons by a warm
($0.40^{+0.02}_{-0.02}\rm\,\,{\rm keV}$), optically thick
($\tau=12.7^{+0.5}_{-0.4}$) and compact ($<15\rm r_{g}$) corona or as the
blurred reflection from an untruncated and moderate to highly ionized
accretion disk. However, for the blurred reflection, the model requires some
extreme configuration (e.g., $\rm A_{Fe}<0.7$ and $\rm R\sim 5$) of the disk
and corona.

  * •

We confirm the presence of a broad Fe emission line at $\sim 6.4\rm\,\,{\rm
keV}$ in the source spectra with an equivalent width of $62-95\,{\rm\,eV}$.

  * •

Our broadband spectral modelling of ESO 511-G030 with both sets of physical
models favour a rapidly spinning black hole ($a>0.78$) and a compact corona,
indicating a relativistic origin of the Fe emission line.

##  6 Acknowledgements

The authors are grateful to the anonymous referee for insightful comments
which improved the quality of the paper. RG acknowledges the financial support
from Visva-Bharati University and IUCAA visitor programme.

##  7 Data availability:

This research has made use of archival data of Suzaku and XMM-Newton
observatories through the High Energy Astrophysics Science Archive Research
Center Online Service, provided by the NASA Goddard Space Flight Center.

Table 1: The X-ray observations of ESO 511–G030.  X-ray | observation | Short | Date of obs | Net exposure | Net counts
---|---|---|---|---|---
Satellite | id | id |  |  |
XMM-Newton | 0502090201 | obs1 | 05-08-2007 | $76\,\rm ks$ | 1.16E+06
Suzaku | 707023020 | obs2 | 22-07-2012 | $224\,\rm ks$ | 3.18E+06
| 707023030 | obs3 | 17-08-2012 | $52\,\rm ks$ | 1.12E+06
Table 2: The comparison of different models used to fit the excess around
$6\rm\,\,{\rm keV}$ for the joint analysis of two Suzaku and XMM-Newton
observations of ESO 511–G030.

Models | Obs-1 | Obs-2 | Obs-3 | Simultaneous fit
---|---|---|---|---
Used | $\,\rm\chi^{2}/dof$ | $\,\rm\chi^{2}/dof$ | $\,\rm\chi^{2}/dof$ | $\,\rm\chi^{2}/dof$
model 1 $+$ zxipcf | 209/109 | 1091/883 | 567/437 | 1868/1420
model 1 $+$ narrow Gaussian | 145/105 | 945/881 | 513/433 | 1603/1417
model 1 $+$ broad Gaussian | 131/104 | 942/880 | 510/433 | 1587/1414
model 1 $+$ diskline | 133/104 | 943/879 | 512/433 | 1587/1414
model 1 $+$ relline | 137/105 | 946/880 | 516/433 | 1599/1411

Notes: Model 1 is above $3\rm\,\,{\rm keV}$ powerlaw fit modified by the
Galactic absorption.
The normalization parameter of all the models were made free for each
observations.

Table 3: The best fit parameters of the baseline phenomenological models for
the XMM-Newton and Suzaku observations of ESO 511–G030.

Models | Parameter | obs1 | obs2 | obs3
---|---|---|---|---
Gal. abs. | $\rm N_{H}\,(\times 10^{20}\,\rm\,\,{\rm cm^{-2}})$ |  $4.34$ (f) |  $4.34$ (f) |  $4.34$ (f)
powerlaw | $\Gamma$ | $1.77^{+0.03}_{-0.02}$ | $1.80^{+0.01}_{-0.01}$ | $1.96^{+0.01}_{-0.01}$
| norm ($10^{-3}$) | $5.13^{+0.01}_{-0.01}$ | $5.21^{+0.01}_{-0.01}$ | $9.1^{+0.41}_{-0.46}$
diskbb (1) |  $T_{in}$ (keV) | $0.36^{+0.01}_{-0.02}$ | $0.23^{+0.01}_{-0.01}$ |  $0.23$ (t)
| norm ($10^{3}$) | $16^{+2}_{-3}$ | $2^{+1}_{-1}$ |  $2$ (t)
diskbb (2) |  $T_{in}$ (keV) | $0.11^{+0.01}_{-0.01}$ | $0.07^{+0.01}_{-0.01}$ | $0.08^{+0.01}_{-0.01}$
| norm ($10^{3}$) | $4.9^{+0.4}_{-0.4}$ | $97.5^{+1.4}_{-3.4}$ | $87.8^{+2.6}_{-0.6}$
diskline | E($\rm\,\,{\rm keV}$) | $6.31^{+0.03}_{-0.03}$ | $6.28^{+0.01}_{-0.02}$ | $6.28^{+0.03}_{-0.03}$
| $\beta$ | $-0.8^{+9.1}_{-0.7}$ | $9.9^{+0.1}_{-10.3}$ |  $9.9$ (t)
| $\rm r_{in}\rm(r_{g})$ |  $6$ (f) |  $6$ (f) |  $6$ (f)
| Incl in(∘) | $10^{+4}_{-7}$ |  $10$ (t) |  $10$ (t)
| norm ($10^{-5}$) | $1.75^{+0.48}_{-0.45}$ | $1.54^{+0.15}_{-0.16}$ | $1.55^{+0.33}_{-0.33}$
|  A$\rm\,\Delta\chi^{2}/dof$ | $178/3$ | $373/3$ | $96/3$
Pexrav B | R |  $-0.56$ (t) | $-0.56^{+0.21}_{-0.12}$ | $-0.74^{+0.13}_{-0.15}$
|  A$\rm\,\Delta\chi^{2}/dof$ | $12/1$ | $34/2$ | $26/1$
$\rm reduced\,\rm\chi^{2}/dof$ |  | $1.28/168$ | $1.13/1699$ | $1.11/1108$

A The $\,\Delta\chi^{2}$ improvement in statistics upon addition of the
corresponding discrete component.
(f) indicates a frozen parameter and (t) indicates parameters are tied between
observations

Table 4: The best-fitting parameters when we modelled the full X-ray energy
band of XMM-Newton and Suzaku observations of ESO 511–G030 with the ionized
reflection model, relxill (Model 1) and the thermal Comptonization model,
optxagnf (Model 2).

Component | parameter |  | obs1 |  |  | obs2 |  |  | obs3 |
---|---|---|---|---|---|---|---|---|---|---
|  | Model 1 |  | Model 2 | Model 1 |  | Model 2 | Model 1 |  | Model 2
Gal. abs. | $\rm N_{H}(10^{20}cm^{-2})$ |  $4.34$ (f) |  |  $4.34$ (f) |  $4.34$(f) |  |  $4.34$(f) |  $4.34$ (f) |  |  $4.34$ (f)
relxill | $\rm A_{Fe}$ | $0.7^{+0.2}_{-0.1}$ |  | - | $<0.6$ |  | - |  $0.5$(t) |  | -
| $\log\xi(\rm\,erg\,cm\,s^{-1})$ | $2.29^{+0.02}_{-0.06}$ |  | - | $3.20^{+0.01}_{-0.01}$ |  | - |  $3.20$ (t) |  | -
| $\Gamma$ | $2.05^{+0.01}_{-0.01}$ |  | - | $1.74^{+0.01}_{-0.01}$ |  | - | $1.88^{+0.01}_{-0.01}$ |  | -
| $\rm E_{cut}(\rm\,\,{\rm keV})$ | $>297$ |  | - |  $388$(t) |  | - |  $388$(t) |  | -
| $n_{rel}(10^{-5})^{a}$ | $8.72^{+0.08}_{-0.15}$ |  | - | $11.24^{+0.16}_{-0.38}$ |  | - | $2.69^{+2.31}_{-0.12}$ |  | -
| $q1$ | $7.3^{+0.3}_{-0.3}$ |  | - | $4.6^{+0.3}_{-1.7}$ |  | - | $8.2^{+0.2}_{-0.9}$ |  | -
| $a$ | $>0.98$ |  | - |  $0.99$ (t) |  | - |  $0.99$ (t) |  | -
| $\rm R(reflfrac)$ | $1.2^{+0.1}_{-0.1}$ |  | - | $0.5^{+0.1}_{-0.3}$ |  | - | $5.3^{+0.3}_{-0.3}$ |  | -
| $\rm R_{in}(r_{g})$ |  $1.24$(f) |  | - |  $1.24$(f) |  | - |  $1.24$(f) |  | -
| $\rm R_{br}(r_{g})$ | $4.9^{+0.4}_{-0.3}$ |  | - | $4.3^{+0.2}_{-0.1}$ |  | - | $3.6^{+0.2}_{-0.3}$ |  | -
| $\rm R_{out}(r_{g})$ |  $400$ (f) |  | - |  $400$(f) |  | - |  $400$(f) |  | -
| $i(degree)$ | $27^{+3}_{-1}$ |  | - |  $27$(t) |  | - |  $27$(t) |  | -
MYTorusL | $i(degree)$ |  $45$ (t) |  |  $45$ (t) |  $45$(f) |  |  $45$(f) |  $45$ (t) |  |  $45$(t)
|  norm ($10^{-3}$) |  $7.37$(t) |  |  $8.18$(t) | $7.37^{+0.40}_{-0.37}$ |  | $8.18^{+0.06}_{-0.04}$ |  $7.37$ (t) |  |  $8.18$(t)
MYTorusS |  NH($10^{24}cm^{-2}$) |  $10.0$(t) |  |  $10.0$ (t) |  $10$(f) |  |  $10$(f) |  $10.0$(t) |  |  $10.0$ (t)
|  norm ($10^{-3}$) |  $3.20$(t) |  |  $6.05$(t) | $3.20^{+1.18}_{-0.71}$ |  | $6.05^{+0.58}_{-0.39}$ |  $3.20$(t) |  |  $6.05$(t)
optxagnf | $M_{BH}^{b}$ | - |  |  $4.57$(f) | - |  |  $4.57$(f) | - |  |  $4.57$(f)
| $d{\rm\leavevmode\nobreak\ (Mpc})$ | - |  |  $95$(f) | - |  |  $95$(f) | - |  |  $95$(f)
| $(\frac{L}{L_{E}})$ | - |  | $0.004^{+0.001}_{-0.001}$ | - |  | $0.008^{+0.001}_{-0.001}$ | - |  | $0.008^{+0.001}_{-0.001}$
| $kT_{e}(\rm\,\,{\rm keV})$ | - |  | $0.39^{+0.12}_{-0.02}$ | - |  | $0.10^{+0.15}_{-0.04}$ | - |  | $0.54^{+0.02}_{-0.10}$
| $\tau$ | - |  | $12.9^{+1.7}_{-1.9}$ | - |  | $>11.8$ | - |  |  $7.9^{+3.0}_{-2.5}$(t)
| $\rm r_{cor}(r_{g})$ | - |  | $11.8^{+4.7}_{-3.3}$ | - |  | $5.2^{+2.7}_{-0.9}$ | - |  |  $5.2$(t)
| $a$ | - |  | $>0.78$ | - |  |  $0.99$(t) | - |  |  $0.99$(t)
| $\rm f_{pl}$ | - |  | $0.56^{+0.03}_{-0.05}$ | - |  | $0.41^{+0.08}_{-0.04}$ | - |  | $0.59^{+0.02}_{-0.07}$
| $\Gamma$ | - |  | $1.74^{+0.01}_{-0.02}$ | - |  | $1.79^{+0.02}_{-0.02}$ | - |  | $1.86^{+0.01}_{-0.03}$
| $\rm reduced\,\rm\chi^{2}/dof$ | $1.37/170$ |  | $1.18/171$ | $1.13/1703$ |  | $1.14/1706$ | $1.05/1110$ |  | $1.09/1112$

Notes: Model 1 = tbabs $\times$ (relxill +MyTorus); Model 2 = tbabs $\times$
(optxagnf +MyTorus)
The MYTorus parameters for obs1 and obs3 are tied with obs2 which is the
longest Suzaku observation (See Table 1)
(f) indicates a frozen parameter. (*) indicates parameters are not
constrained.
(a) $n_{rel}$ reperesent normalization for the model relxill
(b) in units of $10^{8}M_{\odot}$.

Table 5: The best-fitting parameters when we modelled the optical-UV to hard
X-ray energy band of XMM-Newton and Suzaku observations of ESO 511–G030 with
the ionized reflection model, relxill (Model 1) and the thermal Comptonization
model, optxagnf (Model 2).

Component | parameter |  | obs1 |  |  | obs2 |  |  | obs3 |
---|---|---|---|---|---|---|---|---|---|---
|  | Model 1 |  | Model 2 | Model 1 |  | Model 2 | Model 1 |  | Model 2
Gal. abs. | $\rm N_{H}(10^{20}cm^{-2})$ |  $4.34$ (f) |  |  $4.34$ (f) |  $4.34$(f) |  |  $4.34$(f) |  $4.34$ (f) |  |  $4.34$ (f)
diskbb | $T_{in}(\rm\,\,{\rm keV})$ | $0.004^{+0.001}_{-0.001}$ |  | - |  $0.004$(t) |  | - |  $0.004$(t) |  |
|  norm ($10^{10}$) | $2.54^{+2.18}_{-1.42}$ |  | - |  $2.54$(t) |  | - |  $2.54$(t) |  |
relxill | $\rm A_{Fe}$ |  $0.7$ (f) |  | - |  $0.5$ (f) |  | - |  $0.5$ (f) |  | -
| $\log\xi(\rm\,erg\,cm\,s^{-1})$ |  $2.29$ (f) |  | - |  $3.20$(f) |  | - |  $3.20$ (f) |  | -
| $\Gamma$ |  $2.05$ (f) |  | - |  $1.74$(f) |  | - |  $1.88$ (f) |  | -
| $\rm E_{cut}(\rm\,\,{\rm keV})$ |  $388$ (f) |  | - |  $388$(t) |  | - |  $397$(t) |  | -
| $n_{rel}(10^{-5})^{a}$ |  $8.27$(f) |  | - |  $11.24$ (f) |  | - |  $2.69$(f) |  | -
| $q1$ |  $7.3$ (f) |  | - |  $4.6$ (f) |  | - |  $8.2$ (f) |  | -
| $a$ |  $0.99$(f) |  | - |  $0.99$ (t) |  | - |  $0.99$ (t) |  | -
| $\rm R(reflfrac)$ |  $1.2$(f) |  | - |  $0.5$ (f) |  | - |  $5.3$ (f) |  | -
| $\rm R_{in}(r_{g})$ |  $1.24$(f) |  | - |  $1.24$(f) |  | - |  $1.24$(f) |  | -
| $\rm R_{br}(r_{g})$ |  $4.9$ (f) |  | - |  $4.3$ (f) |  | - |  $3.6$ (f) |  | -
| $\rm R_{out}(r_{g})$ |  $400$ (f) |  | - |  $400$(f) |  | - |  $400$(f) |  | -
| $i(degree)$ |  $27$ (f) |  | - |  $27$(t) |  | - |  $27$(t) |  | -
MYTorusL | $i(degree)$ |  $45$ (t) |  |  $45$ (t) |  $45$ (f) |  |  $45$(f) |  $45$ (t) |  |  $45$ (t)
|  norm ($10^{-3}$) |  $7.37$(t) |  |  $8.18$(t) |  $7.37$(f) |  |  $8.18$(f) |  $7.37$ (t) |  |  $8.18$(t)
MYTorusS |  NH($10^{24}cm^{-2}$) |  $10.0$ (t) |  |  $10.0$ (t) |  $10.0$(f) |  |  $10.0$(f) |  $10.0$(t) |  |  $10.0$ (t)
|  norm ($10^{-3}$) |  $3.20$(t) |  |  $6.05$(t) |  $3.20$ (f) |  |  $6.05$(f) |  $3.20$(t) |  |  $6.05$(t)
optxagnf | $M_{BH}^{b}$ | - |  |  $4.57$(f) | - |  |  $4.57$(f) | - |  |  $4.57$(f)
| $d{\rm\leavevmode\nobreak\ (Mpc})$ | - |  |  $95$(f) | - |  |  $95$(f) | - |  |  $95$(f)
| $(\frac{L}{L_{E}})$ | - |  | $0.004^{+0.001}_{-0.001}$ | - |  | $0.007^{+0.001}_{-0.001}$ | - |  | $0.008^{+0.001}_{-0.001}$
| $kT_{e}(\rm\,\,{\rm keV})$ | - |  | $0.40^{+0.02}_{-0.02}$ | - |  | $0.09^{+0.10}_{-0.03}$ | - |  | $0.53^{+0.03}_{-0.10}$
| $\tau$ | - |  | $12.7^{+0.5}_{-0.4}$ | - |  | $>11.9$ | - |  | $7.9^{+2.0}_{-1.7}$
| $\rm r_{cor}(r_{g})$ | - |  | $11.8^{+2.5}_{-1.8}$ | - |  | $5.9^{+1.9}_{-0.5}$ | - |  |  $5.9$(t)
| $a$ | - |  | $>0.98$ | - |  |  $0.99$(t) | - |  |  $0.99$(t)
| $f_{pl}$ | - |  | $0.57^{+0.02}_{-0.02}$ | - |  | $0.41^{+0.06}_{-0.08}$ | - |  | $0.60^{+0.06}_{-0.06}$
| $\Gamma$ | - |  | $1.74^{+0.02}_{-0.02}$ | - |  | $1.79^{+0.01}_{-0.01}$ | - |  | $1.86^{+0.01}_{-0.01}$
| $\rm Reduced\,\rm\chi^{2}/dof$ | $1.38/170$ |  | $1.38/171$ | $1.13/1704$ |  | $1.14/1706$ | $1.05/1108$ |  | $1.09/1112$

Notes: Model 1 = tbabs $\times$ (diskbb + relxill + MyTorus); Model 2 = tbabs
$\times$ (optxagnf +MyTorus)
The MYTorus parameters for obs1 and obs3 are tied with obs2 which is the
longest Suzaku observation (See Table 1)
(f) indicates a frozen parameter. (*) indicates parameters are not
constrained.
(a) $n_{rel}$ reperesent normalization for the model relxill
(b) in units of $10^{8}M_{\odot}$.

Figure 1:  Left: The $4.0-5.0\rm\,\,{\rm keV}$ Suzaku and XMM-Newton spectra
of ESO 511–G030 fitted with an absorbed powerlaw and the rest of the
$0.3-50.0\rm\,\,{\rm keV}$ dataset extrapolated. Bottom panel: The broadband
residuals from the fit above, showing the presence of soft X-ray excess, an Fe
line complex and a hard X-ray excess (at $E>10\rm\,\,{\rm keV}$). The X-axis
represents observed frame energy. Right A zoomed in version of the residual at
the $6\rm\,\,{\rm keV}$ region.

Figure 2:  Left: Left. The $0.3-50.0\rm\,\,{\rm keV}$ Suzaku and XMM-Newton
spectra of the source ESO 511–G030 with the best-fitting reflection model and
residuals. The relxill model describing simultaneously the soft X-ray excess,
the broad Fe $\rm K_{\alpha}$ emission line, and the relativistic reflection
hump in the hard X-rays, the MYTorus model describing the narrow Fe $\rm
K_{\alpha}$ and Ni emission lines along with the Compton hump due to distant
neutral reflection, are plotted in the lower panel. Right: Same for the
Comptonization model optxagnf. The X-axis represents the observed frame
energy.

Figure 3:  Left: Left. The theoretical models are plotted after the joint
fitting of broadband optical-UV to hard X-ray spectra of Suzaku and XMM-Newton
of the source ESO 511–G030 with the relxill (red-diamond) and MYTorus (line
component in blue-circle and scattered component in magenta-triangle) plus the
diskbb (in green-square) model. Right: Same for the second set of physical
models: thermal Comptonization model optxagnf (in green-square) plus MYTorus
(line component in blue-circle and scattered component in magenta-triangle).
The OM data points are plotted as red-star. The X-axis represents the observed
frame energy.

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