Top panel: X-ray orbital modulation of PSR J1048+2339 in 0.3–8 keV with both Chandra observation combined. The phase zero is at same epoch as that in Fig. 1. The time bin size is about 2000 s. The red vertical lines illustrate the locations of inferior conjunction (ϕ = 0.25) and superior conjunction (ϕ = 0.75) of the companion. Middle panel: blue solid and red dashed lines illustrate the orbital modulation in soft band (0.3–2 keV) and hard band (2–8 keV), respectively. Bottom panel: variation of X-ray hardness across the orbit.