The right cardiac border is still intact indicating the right lower lung lobe pneumonia.
The presence of an air bronchogram indicates that the airway proximal to it is patent.
Air bronchograms can be seen with several processes:
pulmonary consolidation
pulmonary edema: especially with alveolar edema
non-obstructive atelectasis
severe interstitial lung disease
neoplasms: bronchioloalveolar carcinoma; pulmonary lymphoma
pulmonary infarct
pulmonary hemorrhage