Table 6: Results of the EPIC PN spectral analysis.
Model Parameters

PL $\cdot$ Abs. $\Gamma=2.77^{+0.04}_{-0.04}$ ; $F_{\rm p12}=4.38^{+0.14}_{-0.13}$

(A) $N_{\rm H20}=16.0^{+0.7}_{-0.6}$

${\bf\chi^2/\nu=1.30}~(621./478)$

PL+Thermal (bbody) $\Gamma=2.50^{+0.09}_{-0.05}$ ; $F_{\rm p12}=3.38^{+0.36}_{-0.18}$ ;

$\cdot$ Abs. kT=.14^+0.01_-0.02;

(B) $L_{39}/D^{2}_{10}=(2.84^{+1.64}_{-0.47})\times 10^{-5}$ ;

$N_{\rm H20}=16.4^{+2.6}_{-1.1}$ ;

${\bf\chi^2/\nu=1.03}~(492./476)$

PL+Thermal (diskbb) $\Gamma=2.51^{+0.07}_{-0.07}$ ; $F_{\rm p12}=3.40^{+0.29}_{-0.26}$ ;

$\cdot$ Abs. $T{\rm in}=.16^{+0.02}_{-0.01}$ ;

(C) $(R_{\rm in}/D)^{2} cos \theta=407^{+516}_{-193}$

$N_{\rm H20}=18.7^{+2.3}_{-0.9}$ ;

${\bf\chi^2/\nu=1.04}~(496./476)$

PL+Thermal (mekal) $\Gamma=2.65^{+.05}_{-.05}$ ; $F_{\rm p12}=3.97^{+0.23}_{-0.19}$ ;

$\cdot$ Abs. kT=.22^+0.02_-0.02; Z=1.0;

(D) $A_{\rm t}=(3.93^{+1.75}_{-0.77})\times 10^{-4}$ ;

$N_{\rm H20}=16.2^{+1.3}_{-0.9}$ ;

${\bf\chi^2/\nu=1.06}~(505./476)$

PL+Thermal (mekal+ $\Gamma=2.52^{+.06}_{-.08}$ ; $F_{\rm p12}=3.42^{+.22}_{-0.32}$ ;

bbody) $\cdot$ Abs. $kT_{\rm mekal}=.15^{+0.03}_{-0.04}$ ; Z=1.0;

(E) $A_{\rm t}=(4.6^{+10.3}_{-2.0})\times 10^{-4}$ ;

$kT_{\rm bbody}=.15^{+0.01}_{-0.03}$ ;

$L_{39}/D^{2}_{10}=(2.2^{+1.3}_{-0.6})\times 10^{-5}$ ;

$N_{\rm H20}=16.9^{+1.3}_{-1.7}$ ;

${\bf\chi^2/\nu=0.98}~(463./474)$

Fit parameters are shown with 90% errors ( $\Delta \chi^2=2.7$ ). The model and parameter definitions are: model components - PL: power-law with a photon index of $\Gamma$ and a 0.5-2 keV flux of $F_{\rm p12}$ in units of 10^-12 erg cm^-2 s^-1. Thermal - thin plasma: thermal plasma using the XSPEC mekal model with a plasma temperature kT [keV], a metal abundance Z=1 in solar units, and the normalization defined by XSPEC $A_{\rm th}$ . Thermal - multi color disk: the multicolor disk (Mitsuda et al. 1984) distributed as the XSPEC model (diskbb) with an inner disk temperature $kT_{\rm in}$ and with an normalization defined as $(R_{\rm in}/D) \cos \theta$ , where $R_{\rm in}$ is the inner disk radius and D is the distance to the source in 10 kpc units, and $\theta$ is the viewing angle of the disk axis. Thermal - thick plasma: thermal thick plasma using the XSPEC bbody model with a plasma temperature kT [keV], with a normalization defined as L₃₉/ D²₁₀, where L₃₉ is the source luminosity in units of 10³⁹ erg s^-1 and D₁₀ is the distance to the source in units of 10 kpc. Abs: absorption by neutral gas using the XSPEC model wabs (Morrison R. McCammon D. 1983, ApJ 270 190) with hydrogen column density $N_{\rm H20}$ $[10^{20}~{\rm cm}^{-2}]$ .

**Table 6:** Results of the EPIC PN spectral analysis.
Model	Parameters
PL $\cdot$ Abs.	$\Gamma=2.77^{+0.04}_{-0.04}$ ; $F_{\rm p12}=4.38^{+0.14}_{-0.13}$
(A)	$N_{\rm H20}=16.0^{+0.7}_{-0.6}$
	${\bf\chi^2/\nu=1.30}~(621./478)$
PL+Thermal (bbody)	$\Gamma=2.50^{+0.09}_{-0.05}$ ; $F_{\rm p12}=3.38^{+0.36}_{-0.18}$ ;
$\cdot$ Abs.	kT=.14^+0.01_-0.02;
(B)	$L_{39}/D^{2}_{10}=(2.84^{+1.64}_{-0.47})\times 10^{-5}$ ;
	$N_{\rm H20}=16.4^{+2.6}_{-1.1}$ ;
	${\bf\chi^2/\nu=1.03}~(492./476)$
PL+Thermal (diskbb)	$\Gamma=2.51^{+0.07}_{-0.07}$ ; $F_{\rm p12}=3.40^{+0.29}_{-0.26}$ ;
$\cdot$ Abs.	$T{\rm in}=.16^{+0.02}_{-0.01}$ ;
(C)	$(R_{\rm in}/D)^{2} cos \theta=407^{+516}_{-193}$
	$N_{\rm H20}=18.7^{+2.3}_{-0.9}$ ;
	${\bf\chi^2/\nu=1.04}~(496./476)$
PL+Thermal (mekal)	$\Gamma=2.65^{+.05}_{-.05}$ ; $F_{\rm p12}=3.97^{+0.23}_{-0.19}$ ;
$\cdot$ Abs.	kT=.22^+0.02_-0.02; Z=1.0;
(D)	$A_{\rm t}=(3.93^{+1.75}_{-0.77})\times 10^{-4}$ ;
	$N_{\rm H20}=16.2^{+1.3}_{-0.9}$ ;
	${\bf\chi^2/\nu=1.06}~(505./476)$
PL+Thermal (mekal+	$\Gamma=2.52^{+.06}_{-.08}$ ; $F_{\rm p12}=3.42^{+.22}_{-0.32}$ ;
bbody) $\cdot$ Abs.	$kT_{\rm mekal}=.15^{+0.03}_{-0.04}$ ; Z=1.0;
(E)	$A_{\rm t}=(4.6^{+10.3}_{-2.0})\times 10^{-4}$ ;
	$kT_{\rm bbody}=.15^{+0.01}_{-0.03}$ ;
	$L_{39}/D^{2}_{10}=(2.2^{+1.3}_{-0.6})\times 10^{-5}$ ;
	$N_{\rm H20}=16.9^{+1.3}_{-1.7}$ ;
	${\bf\chi^2/\nu=0.98}~(463./474)$

Source LaTeX | All tables | In the text

	1 Introduction
	2 Observations and data reduction
	3 Optical counterpart of the ULX HoII X-1
	4 Emission line properties
	5 Chandra and XMM observations of HoII X-1
	6 Discussion
	References