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Figure 1: X-ray spectrum of Nova LMC 2000 as observed with XMM- Newton on 28 August 2000, modelled with a bremsstrahlung (left) and Raymond-Smith model (right). The top panel shows the count rate spectrum and the residuals, while the lower panels show the unfolded photon spectrum. |
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Figure 2:
Finding chart of N LMC 2000 in the V band (left; marked
with two dashes near the image center) and at 2120 Å (right). The V band image was taken on 2000 Dec. 4
with DFOSC at the 1.5 m Danish telescope at La Silla (ESO).
We measure RA = 5![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
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Figure 3: Light curve of Nova LMC 2000 as measured by various observers and provided to VSNET (filled circles). Our ground-based observation from Dec. 2000 is marked by a filled triangle, and the XMM/OM observation in August 2000 by a filled lozenge. The cross marks the possible maximum as determined by a backwards extrapolation (see introduction). Vertical dashes at the top mark the times of the XMM- Newton observations. The dashed line visualizes the decay curve of the recurrent nova CI Aql (see Greiner & Di Stefano 2002), scaled to the LMC distance. While the early decay of N LMC 2000 was substantially faster, the optical brightness in Dec. 2000 is consistent with the nova still being in the plateau phase. For comparison purposes also overplotted (with small dots) is the VSNET light curve of nova V1494 Aql (scaled in brightness) which has very similar t2 and t3 times. |
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Figure 4:
Correlation between the envelope expansion velocity and the
turn-off times of novae (see Table 4).
For GQ Mus, Nova Cyg 1992 and V382 Vel two points are plotted,
resembling the temporal limits between observed supersoft X-ray emission
and H burning switch-off. For CI Aql and U Sco only limits are
available. Nova LMC 2000 does not fit into this correlation unless
the intrinsic absorbing column for the supersoft X-ray emission
has been muc larger than estimated in Sects. 2 and 3.
If the relation were true, one would predict that IM Nor with its
rather small expansion velocity would turn into a long-lived
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Figure 5: Correlation between the orbital periods and the turn-off times of novae (see Table 4). Symbols and limits as in Fig. 4. |
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Figure 6: Correlation between the turn-off times of novae (see Table 4) and the ratio of left-over mass to the critical mass where H shell burning will cease. Symbols and limits as in Fig. 4. |
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