Astronomy & Astrophysics

All Figures

$\begin{figure} \par\includegraphics[angle=180,width=16cm,clip]{3879f1.ps}\end{figure}$ Figure 1: The outburst history of 4U 1608-52 from 1996-2003 according to the ASM/RXTE observations. a) Sum band (1.5-12 keV) light curve. The points represent the one-day means and are connected by the lines for the densely covered intervals. The horizontal bars denote the intervals of the low active state (LAS). The vertical lines mark the moments of the conjunction of 4U 1608-52 with the Sun. b) The hardness ratio HR1. c) The hardness ratio HR2. The uncertainties quoted in the original file of the RXTE measurements are marked. See Sect. 3.1 for details.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=14cm,clip]{3879f5.ps}\end{figure}$ Figure 5: A comparison of the decay branches of the individual outbursts in 4U 1608-52, based on the ASM/RXTE observations. The individual outbursts were shifted along the time axis to match the decay branch of the template - the time of crossing 13 ct/s and the shifts with respect to the template are listed in the figure. The thick curve represents the smooth decay curve. A smoothed decay branch of the outbursts of Aql X-1 (from Simon 2002a) is shown for comparison. See Sect. 3.2.1 for details.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=14cm,clip]{3879f6.ps}\end{figure}$ Figure 6: A comparison of the rising branches of the individual outbursts in 4U 1608-52. The arrangement is similar to Fig. 5. The time of crossing 20 ct/s and the shifts with respect to the template are listed in the figure. One very bright outburst of Aql X-1 is shown for comparison. See Sect. 3.2.2 for details.
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In the text

$\begin{figure} \par\includegraphics[angle=180,width=8.8cm,clip]{3879f7.ps}\end{figure}$ Figure 7: a) $\rm O{-}C$ diagram for the moments of the outburst maxima in 4U 1608-52, determined from the ASM/RXTE data. The Julian Dates (JD-2 400 000), labeled for some points, allow an easy comparison with Fig. 1a. The range of the ordinate is equal to the length of $T_{\rm C}$ to allow for an assessment of the range of variations. b) The course of $I_{\rm max}$ . c) The course of $D_{\rm out}$ . The solid and empty circles denote the lower and upper limits of $D_{\rm out}$ , respectively. See Sect. 3.3 for details.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=14cm,clip]{3879f8.ps}\end{figure}$ Figure 8: The dependence of HR1 and HR2 on $I_{\rm sum}$ in decays of outbursts in 4U 1608-52 ( HR with $\sigma _{\rm q}\leq 0.07$ only). The smooth solid line represents the fit by HEC13. For comparison, the dashed line denotes the fit to the data set with HR1 with $\sigma _{\rm q}\leq 0.3$ . See Sect. 3.4 for details.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=15cm,clip]{3879f2.ps}\end{figure}$ Figure 2: The profiles of two bright and long outbursts in 4U 1608-52, based on the ASM/RXTE observations. The sum band (1.5-12 keV) light curve, HR1 (solid circles) and HR2 (empty circles) are shown. The points represent the one-day means and are connected by the lines for the densely covered intervals. The vertical marks denote the starting points of the parts of the decay branches which were used for the fitting procedure in Sect. 3.2.1. The scales of the axes are identical for both events. See Sect. 3.1 for details.
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In the text

$\begin{figure} \includegraphics[angle=-90,width=15cm,clip]{3879f3.ps}\end{figure}$ Figure 3: The profiles of four short and relatively faint outbursts in 4U 1608-52. The arrangement is analogical to that of Fig. 2, but the scale of the abscissa is twice as large. See Sect. 3.2.1 for details.
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In the text

$\begin{figure} \par\includegraphics[angle=180,width=8.8cm,clip]{3879f4.ps}\end{figure}$ Figure 4: The profile of the bright and very long outburst in 4U 1608-52, having its maximum in JD 2 452 482. The arrangement of a) and b) is the same as that of Fig. 2. The profile of the light curve plotted for the logarithmic scale of $I_{\rm sum}$ is shown in c). See Sect. 3.2.1 for details.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=14cm,clip]{3879f6.ps}\end{figure}$	Figure 6: A comparison of the rising branches of the individual outbursts in 4U 1608-52. The arrangement is similar to Fig. 5. The time of crossing 20 ct/s and the shifts with respect to the template are listed in the figure. One very bright outburst of Aql X-1 is shown for comparison. See Sect. 3.2.2 for details.
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$\begin{figure} \par\includegraphics[angle=-90,width=14cm,clip]{3879f8.ps}\end{figure}$	Figure 8: The dependence of HR1 and HR2 on $I_{\rm sum}$ in decays of outbursts in 4U 1608-52 ( HR with $\sigma _{\rm q}\leq 0.07$ only). The smooth solid line represents the fit by HEC13. For comparison, the dashed line denotes the fit to the data set with HR1 with $\sigma _{\rm q}\leq 0.3$ . See Sect. 3.4 for details.
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$\begin{figure} \includegraphics[angle=-90,width=15cm,clip]{3879f3.ps}\end{figure}$	Figure 3: The profiles of four short and relatively faint outbursts in 4U 1608-52. The arrangement is analogical to that of Fig. 2, but the scale of the abscissa is twice as large. See Sect. 3.2.1 for details.
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$\begin{figure} \par\includegraphics[angle=180,width=8.8cm,clip]{3879f4.ps}\end{figure}$	Figure 4: The profile of the bright and very long outburst in 4U 1608-52, having its maximum in JD 2 452 482. The arrangement of a) and b) is the same as that of Fig. 2. The profile of the light curve plotted for the logarithmic scale of $I_{\rm sum}$ is shown in c). See Sect. 3.2.1 for details.
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