Infrared Spectroscopic Study of NGC 2024
Abstract
Near-infrared spectrophotometric observations of the obscured H II region NGC 2024 are presented. The data include Br-gamma line and 3.29-micron intensity distributions in an area of about 2.5 arcmin x 1.5 arcmin, together with measurements in several positions of the Br-alpha line, the He I (2.058 micron) line, and 3.07 microns-ice-band absorption. The spectrophotometry of NGC 2024 IRS 2 is also presented. The integrated flux of the Br-gamma line in the region observed is estimated, as about 9 x 10 to the -18th W/sq cm, at least three times as large as that of IRAS 2. The Br-gamma map has a general similarity to available radio continuum maps, especially in the peak region at around 20 arcsec south of IRS 2, but farther south, Br-gamma emission seems to be heavily obscured. The 3.29-micron band emission, which is strongest at about 55 arcsec south of IRS 2, has an elongated distribution along the east-west direction. It is also shown that the extended continuum emission in near-infrared wavelengths can be interpreted by small hot grains with a typical temperature of about 1000 K. By combining these observations, the nature of exciting stars is discussed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1990
- DOI:
- 10.1086/168714
- Bibcode:
- 1990ApJ...354..549M
- Keywords:
-
- Astronomical Spectroscopy;
- H Ii Regions;
- Infrared Spectroscopy;
- Molecular Clouds;
- Infrared Spectra;
- Interstellar Extinction;
- Interstellar Matter;
- Near Infrared Radiation;
- Spectrophotometry;
- Stellar Spectra;
- Astrophysics;
- INFRARED: SPECTRA;
- INTERSTELLAR: GRAINS;
- NEBULAE: H II REGIONS;
- NEBULAE: INDIVIDUAL NGC NUMBER: NGC 2024