Table 1: Models of the PN spectrum of XMMU J174554.4-285456, taking into account absorption. po: power law. bb: black body. diskbb: multi black body (Mitsuda et al. 1984). brems: bremsstrahlung. The number of degrees of freedom is 161. The column density is expressed in units of 10²² cm^-2. The flux ( $F_{\rm X}$ ) and luminosity ( $L_{\rm X}$ ) corrected for absorption are expressed in 10^-11 erg cm^-2 s^-1 and 10³⁵ erg s^-1, respectively. The luminosity is calculated assuming d=8 kpc.
Model ${\cal N}_{\rm H}$ $\Gamma$ or kT $\chi^{2}_{\rm red}$ $F_{\rm X}$ $L_{\rm X}$ $F_{\rm X}$ $L_{\rm X}$

2-10 keV 0.5-10 keV

po $\rm 14.1^{+1.6}_{-1.4}$ $\rm 1.65^{+0.17}_{-0.16}$ 0.87 1.4 1.0 2.1 1.5

bb $7.3\pm0.9$ $1.9\pm0.1$ 1.08 1.0 0.7 1.0 0.7

diskbb $11.0\pm1.0$ $3.7\pm0.5$ 0.93 1.2 0.9 1.4 1.0

brems $13.6\pm1.2$ $\rm 22^{+40}_{-15}$ 0.88 1.3 0.9 1.8 1.3

**Table 1:** Models of the PN spectrum of XMMU J174554.4-285456, taking into account absorption. `po`: power law. `bb`: black body. `diskbb`: multi black body (Mitsuda et al. 1984). `brems`: bremsstrahlung. The number of degrees of freedom is 161. The column density is expressed in units of 10²² cm^-2. The flux ( $F_{\rm X}$ ) and luminosity ( $L_{\rm X}$ ) corrected for absorption are expressed in 10^-11 erg cm^-2 s^-1 and 10³⁵ erg s^-1, respectively. The luminosity is calculated assuming d=8 kpc.
Model	${\cal N}_{\rm H}$	$\Gamma$ or kT	$\chi^{2}_{\rm red}$	$F_{\rm X}$	$L_{\rm X}$	$F_{\rm X}$	$L_{\rm X}$
				2-10 keV	0.5-10 keV
`po`	$\rm 14.1^{+1.6}_{-1.4}$	$\rm 1.65^{+0.17}_{-0.16}$	0.87	1.4	1.0	2.1	1.5
`bb`	$7.3\pm0.9$	$1.9\pm0.1$	1.08	1.0	0.7	1.0	0.7
`diskbb`	$11.0\pm1.0$	$3.7\pm0.5$	0.93	1.2	0.9	1.4	1.0
`brems`	$13.6\pm1.2$	$\rm 22^{+40}_{-15}$	0.88	1.3	0.9	1.8	1.3

Source LaTeX | All tables | In the text

	1 Introduction
	2 XMM-Newton observation
	3 Spectral analysis
	4 Period analysis
	5 The nature of XMMU J174554.4-285456
	References