SIMBAD references

Soft X-ray emission (0.5-2.0keV) from the star forming regions of NGC 2023 and NGC 2024 was detected during pointed ROSAT PSPC observations. Nearly all emission from NGC 2024 can be resolved into numerous point sources, with a number density (>103 per square degree) close to the confusion limit. An X-ray catalog of the central region of NGC 2024 is presented. Most of the sources appear to be highly absorbed (log(N_H)∼22[cm-2]) low-mass young stellar objects(log(L_X)∼29-31[erg/s), deeply embedded in the parent molecular cloud. In contrast to NGC 2024, the stellar cluster in NGC 2023 could not be detected in X-rays except for its most eastern member (NGC 2023/S105), especially, the B1.5Vstar HD 37903 appeared much fainter than 'generic' early-type stars.