NIR and MIR extinction toward the TMC1A jet. Same as Figure 2, but extended to include additional a⁴D lines in the NIR (left) used for n_e derivation, along with MIR lines (right). Model scatter points correspond to the derived electron density at 10 000 K (see Section 4.2), with uncertainties reflecting the uncertainty range in the determined n_e value and temperatures from 5000–10 000 K. Commonly used NIR/MIR extinction curves are overplotted for comparison (see text).