Images of star-forming regions. III. Sources in the NGC 7538 molecular cloud complex

Journal Article · Fri Apr 01 04:00:00 EST 1988 · Astron. J.; (United States)

DOI:https://doi.org/10.1086/114714· OSTI ID:7252085

Campbell, B; Persson, S E

Deep optical CCD images of the embedded infrared sources associated with NGC 7538 are presented. A reflected image of IRS 1, the most luminous infrared source in the region, is shown to be positionally offset from the VLA radio source in a direction that is consistent with that of the blueshifted portion of the bipolar molecular outflow toward the north. Maps of the IRS 1 region at 1.65 and 2.2 microns, made with a prototype infrared camera, confirm the positional displacement. The H-K color of IRS 1 is extremely red (greater than 5 mag), which shows that the radio source is indeed totally obscured at wavelengths less than 1.5 micron. This is also consistent with other estimates of the extinction to IRS 1. New VLA radio images of IRS 2 and IRS 3 are also presented. The peculiar object IRS 9, a source that displays deep absorption due to CO molecules in the solid phase, is associated with a diffuse optical nebula that corresponds with the infrared reflection nebula found by Werner et al. (1979). The young stellar objects in NGC 7538 represent a broad evolutionary range in high-mass star formation, from a fully evolved blister-type H II region to much younger objects which have yet to break through their protostellar cocoons. 35 references.

• Research Organization: Mount Wilson and Las Campanas Observatories, Pasadena, CA (USA)
• OSTI ID: 7252085
• Journal Information: Astron. J.; (United States), Journal Name: Astron. J.; (United States) Vol. 95; ISSN ANJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
COSMIC GASES
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
FLUID FLOW
FLUIDS
GAS FLOW
GASES
H2 REGIONS
IMAGES
INFRARED RADIATION
INTERSTELLAR SPACE
MASS
MOLECULES
OXIDES
OXYGEN COMPOUNDS
PROTOSTARS
RADIATIONS
SPACE
STAR EVOLUTION