UV Continuum in HH 47A

The measured and predicted continuum emission in the Mach disk (right) and bow shock spectra (left). The continuum points were each extracted from the data in 20A intervals devoid of emission lines. Top: Both spectra show a bright UV continuum whose spectrum is bluer than that expected from 2-photon emission when reduced according to the standard pipeline and dereddened with Av = 0.57. Middle: When the effects of high geomagnetic latitude are removed from the data, the blue continua become less striking and the anomalous red continuum in the Mach disk vanishes. Bottom: With correct dark count subtraction and a lower reddening, both the Mach disk and bow shock continua have shapes consistent with those expected from 2-photon emission. The luminosity of the 2-photon emission can be found from these plots and the bolometric corrections in Table 4 of the paper.