| From: | 1.00 | 1.33 | 1.67 | 2.00 | 2.33 | 2.67 | 3.00 | 3.33 | 3.67 | 4.00 | 4.33 | |
| λ | To: | 1.22 | 1.56 | 1.89 | 2.22 | 2.56 | 2.89 | 3.22 | 3.56 | 3.89 | 4.22 | 4.55 |
| Ca II K3 | 99,99,95 | 99 | 95 | 99 | 95 | 95,95 | ||||||
| Hα | 99,95 | 99,95 | 99 | 99 | 95,95 | 95,99 | ||||||
| Mg I b2 | 99,99 | 99 | 95 | 99 | 99 | |||||||
| Mg I b1-0.4 Å | 99 | 99,95 | 99 | 95 | 99 | 95 | ||||||
| Wavelengths | Correlation Coefficient | Frequency (mHz) | Timelag (Units of 45 s) | Speed (km s-1 | |
| λ1 | λ2 | ||||
| Ca II K3 | Hα | 0.82 - 0.84 | 3.65 - 3.85 | -8 - -9 | <2 |
| 0.6 - 0.76 | 3.3 - 3.5 | 0 - 1 | 2+ | ||
| Ca II K3 | Mg I b2 | 0.64 - 0.76 | 0.9 - 1.1 | -1 - -8 | 3-29 |
| 0.56 - 0.77 | 1.05 - 1.25 | 0 - -1 | 23+ | ||
| Ca II K3 | Mg I b1-0.4 Å | 0.58 - 0.60 | 4.55 - 4.75 | -6 - -7 | 5-7 |
| Hα | Mg I b2 | 0.55 - 0.67 | 1.2 - 1.4 | 0 - -5 | 2-22+ |
| Hα | Mg I b1-0.4 Å | 0.67 - 0.68 | 4.15 - 4.35 | 2 | 11-17 |
| Mg I b2 | Mg I b1-0.4 Å | 0.80 - 0.86 | 1.48 - 1.68 | 0 - 2 | 6-12+ |
| 0.62 - 0.63 | 4.0 - 4.2 | -3 | 4 | ||
In the 1.2-1.6 mHz range, there appear to be two different correlation patterns. A ~1.3 mHz correlation (Ca II K3 and Hα to Mg I b2)corresponds to a decrease in power (and hence significance) of this frequency in the upper lines. There is also an appearance of signal at ~2.7 mHz in Hα and Ca II K3. Although this ~2.7 mHz frequency also occurs in the lower lines, it seems to be uncorrelated to the upper lines. However there is a lack of correlation between Hα and Ca II K3 at ~2.7 mHz (Test 4) (although this could be due to the longitudinal wave shocking) and the waves may be downward- moving. Also, similar to NBP2, it is of a very low frequency compared to Kalkofen (1997). A ~1.6 mHz correlation between Mg I b2 and Mg I b1-0.4 Å corresponds to a disappearance of power at this frequency from Mg I b1-0.4 Å to Mg I b2, as well as the existence of a ~3.1 mHz oscillation in Mg I b2. However, the lack of a remnant peak (Test 1) in the upper line makes this a less likely candidate for mode coupling. It would also have coupled too low in the atmosphere to be a viable candidate for chromospheric heating.
The correlation at 4.25 mHz (Hα to Mg I b1-0.4 Å) corresponds to an appearance at this frequency in Hα, and could be the indication of a longitudinal wave appearing at this height. There is also power at 2.1 mHz in the lower lines. However, as there in no correlation at 2.1 mHz, and the power at this frequency does not decrease with height, this is not a good candidate for mode-coupling. There is a further upward- moving wave at 3.4 mHz (Ca II K3 to Hα).
There appear to be three downward- moving waves at 1.0 mHz (Ca II K3 to Mg I b2), 3.75 mHz (Ca II K3 to Hα) and 4.65 mHz (Ca II K3 to Mg I b1-0.4 Å), corresponding to wave-packets in each wavelength. Bocchialini & Baudin (1995) also found a downward- moving wave at 3.5 mHz using a similar method and invoked the magneto-gravity waves suggested by Deubner & Fleck (1990). The 4.1 mHz correlation (Mg I b2 to Mg I b1-0.4 Å) does not correspond to any wave-packets, and is thus dismissed as not being real. Again, there seem to be a few oscillations which are localised in height, mainly in the range 2.67-3.56 mHz in Mg I b2 and Mg I b1-0.4 Å. For the frequencies around 3.33 mHz this could be due to some photospheric leakage. However, as this does not occur in all NBPs, it seems unlikely to be the case.