+0.7 −0.6
Fan-C 129.1 -68 South Pole 151.6 -90 -Fan-D 166.4 -75
+12.9 −5.7
+5.1 −2.3
Fan-E 187.5 -54
+3.6 −2.5
Fan-F 211.8 -30
Notes. Fan column refers to the designation of the dust fan, as defined by this work. Position angle was measured from North to East, counterclockwise, at each of the dates. Nucleus Latitude ϕ is the conversion from plane-of-sky position angles and approximate latitudes of nucleus sources, assuming a spherical nucleus. σPA denotes the uncertainty in measurement of the position angles. Dust fans benefit from different upper and lower uncertainties due to their higher SNR signal, which allowed for more robust fits along their radial extent.

tures from the Voigt models, denoted as Fans C, D, E, and F. We found that Fans C and E correlate to structures detected in our CWT maps, however, note that Fans D and F have less precise associations. Considering this is an approximation of source latitude, we suggest that the bulk of post-perihelion dust emission came from between latitudes -10◦to -30◦S (Fan F), -40◦to -50◦S (Fans C and E), and -60◦to -80◦S (Fan D). Intriguingly, Fans C and E were generally symmetric around the South Pole, hinting that they are projections of the same dust structure and activity source, discussed further in Section 4. The position angle of each fan is self-consistent over the period of a month, similar to both pre-perihelion fans, suggesting long-term stability of these structures. However, all post-perihelion fans are linear and devoid of any substantial curvature, unlike the pre-perihelion fans. This is likely due to our viewing geometry, which is nearly head-on (phase angle of ∼10◦, so most curvature would likely be away from Earth and imperceivable. Fans C through F are labelled and can be seen in the right-most panel of Figure 4, or in the unlabelled panels (IX.) through (XII.) in Figure 3.
3.1.2. Gas Morphology Unlike dust Fans A-F, the gas structures exhibit complex and evolving morphologies that differ over species and epoch, as seen in Figures 5 to 8. Water sublimation is the primary driver of cometary activity within a few au (Bockel´ee-Morvan et al., 2004), and can be traced in the optical regime via green (5577.339 ˚A) and red-doublet (6300.304, 6363.776 ˚A) electronic transition lines of oxygen atoms from metastable 1S and 1D states (Decock et al., 2013). Destructive excitation of neutral oxygen-bearing molecules, such as H2O, CO2, and CO, are the primary sources of these forbidden metastable [OI] states (Bhardwaj and Haider, 2002). Although CO2 and CO dissociation can contribute to both green and red-doublet emissions, at close heliocentric distances the red-doublet flux is dominated by H2O dissociation, thus making it ideal to probe the H2O morphology of 67P (Decock et al., 2013). We use the red-doublet lines to construct maps of this morphology over the entire campaign.

I. II. III.
IV. V. VI.
VII. VIII. IX.
X. XI. XII.

[Figure: Figure 5: 6300.304 ˚A [OI] line from 6296.5-6305.8 ˚A, and the 6363.776 ˚A [OI] line from 6361.2-6365.7 ˚A Enhanced red-doublet [OI] maps, from 15 May 2021 to 09 March 2022. Red arrow denotes sky projection of the Northern pole orientation (2016 Rosetta solution). Lime arrow is the velocity vector. Yellow arrow is the Sun angle. North is up and East is left, denoted by white arrows. Concentric dashed rings denote projected cometocentric distance, ρ, as projected onto the sky, in units of 103 kilometres. No rebinning has been applied.]