All Figures

Figure 1: Spectra of the Sun in the wavelength ranges from 116 nm to 118 nm in the first order and 58 nm to 59 nm in the second order covering the He  I line at 58.43 nm and the four spectral humps. The QS spectrum observed near the centre of the Sun on 28 April 1996 is plotted as solid line, and a polar CH spectrum from 5 June 1996 as dotted line. The radiances of both spectra are normalized to the maximum of the helium line. The photon responsivity ratio is r(58 nm, KBr)/r(117 nm, KBr) = 0.12, and thus the helium line is much brighter than shown. The data of the equatorial corona 30  above the west limb next to a prominence on 25 June 1996 are shown as a dashed line. A strong Si  XI line can be seen at 58.08 nm in the second order, in addition to two Si  VII lines in the first order at 116.77 nm and 116.93 nm. In coronal spectra of SUMER, the C  III multiplet mainly consists of scattered radiation from the primary mirror. These observations were performed with detector A on the KBr photocathode. Also shown (with a scale on the right-hand side) is the spectral radiance ratio, (CH)/ (QS), measured on 7 March 1999 with detector B, when sections of the slit covered both regions.

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In the text

	Figure 2: Spectral range of the raster scan shown in Fig. 3. The sections of the spectrum used for compiling the maps are indicated. The observations were performed with detector B and the    slit. Note that the short-wavelength hump 1 was put on the KBr photocathode, whereas the long-wavelength humps 2 and 3 were on the bare MCP in this case.
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In the text

Figure 3: A QS area simultaneously recorded during a single raster scan in various VUV emissions. Upper row: C  I and S  I (on KBr); He  I and C  III (on the bare MCP). Lower row: continuum; hump 1 (KBr); humps 2 and 3 (bare). The continuum is subtracted as background from the other emissions. The area has a N-S extension of 110 Mm and an E-W extension of 71 Mm. The observations were made near the centre of the Sun on 26 February 1999.

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In the text

	Figure 4: Temporal variations of the radiances of the helium line and the humps 1 and 2 in a QS region separated into network and internetwork areas. The exposures were taken with detector A and the    slit. A bright section of 16 in the helium line was considered to represent a network lane, and an adjacent darker section of 19 an internetwork region.
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In the text

Figure 5: Stigmatic limb spectrum with humps 1 to 3 on the KBr photocathode of detector B. The C  III multiplet was recorded on the bare MCP. The spectral ranges selected for further analysis of the humps are indicated by horizontal bars. The continuum background was subtracted. The spectral calibration was obtained from the S  I line at 115.627 nm and the C  III line at 117.637 nm (both shown in the upper margin). The spectral positions of the known C  I, S  I, N  I, Cl  I, S  II, Fe  II, and C  III lines in this range are marked by vertical bars. The lines seen in the second order and the Si  VII lines are taken from Feldman et al. (1997). Two lines could not be identified.

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In the text

Figure 6: a) Limb brightening curves of spectral features displayed in Fig. 5. The radiances of the He  I line and the humps 1 to 3 are given in arbitrary (photon) units (the same for all four of them). The spectral radiances of the continuum and the other emission lines are normalized to the hump 1 (not blended by N  I contributions) anddisplaced in steps of 0.5 to avoid confusion. Based on the counting statistics, some standard uncertainties are indicated. The N  I line is that at 117.195 nm, where Kelly (1987) lists a N  I line, albeit with much lower relative radiance than observed. The identification therefore is tentative. b) Ratios of the hump 2/hump 1 radiances and of twice the first-order hump 1 relative to the helium line. The latter ratio is also shown as dashed line under the assumption that the hump is seen in the second order with a maximum off the scale.

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In the text

	Figure 7: Limb observations on the bare MCP with adequate counting statistics. The lower rates lead to somewhat larger standard uncertainties than for KBr. The radiance ratio of hump 1 to helium is virtually identical to that of the KBr case if different orders are assumed, but is very different for the same order (dashed line) (cf. Fig. 6b).
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In the text

Figure 8: Cross-correlation analyses of the limb scans with the 1  hole, plotted with respect to the peak position of hump 1. a) North pole: one step corresponds to 270 km in height (upper scale). Details on the relative shifts are compiled in Table 2. b) South-west limb: here one step corresponds to 90 km in height. The shifts are in reasonable agreement with those in panel  a) and are also given in Table 2.

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In the text

	Figure 9: Prominence and filament observations in May 2004 in comparison with a QS area. The filament radiance is displayed 0.5 higher than the QS scale; the prominence spectrum is shifted by 2.0. The peak spectral radiance of the helium line in the prominence is normalized to the corresponding QS value. Also shown is the ratio of the spectral radiances  (FIL)/ (QS).
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In the text