The spectral and spatial distribution of radiation from Eta Carinae. III - A high-resolution 2.2 micron map and morphological considerations of the evolutionary status

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

23

Astronomical Maps, Infrared Astronomy, Planetary Nebulae, Radiation Distribution, Stellar Evolution, Accretion Disks, Cosmic Dust, High Resolution, Near Infrared Radiation, Thermal Emission

Scientific paper

A high spatial resolution map of η Carinae at 2.2 μm is presented. The map, in which a beam width (FWHM) of 1".1 was employed, shows that the previously identified double-peaked nature of the inner region of the homunculus in the wavelength range 3.6-11.2 μm is also strongly evident at 2.2 μm. Comparison with previous results shows the secondary maximum to be relatively more intense at 2.2 μm than at 3.6 μm. A consideration of the volume emission coefficients for thermal emission and scattering reveals, rather surprisingly, that at 2.2 μm the secondary source is likely to be due to thermal emission by dust grains rather than to scattering, which is responsible for the visible reflection nebula. If so, the data imply a difference in the near-infrared dust emissivity in the regions producing the two peaks. In particular, the material in the secondary shows evidence for a more steeply decreasing emissivity toward longer wavelengths than in the primary, possibly implying an enhancement of "clean" silicate material in the secondary. A consideration of the morphology of the homunculus confirms that η Car may be viewed as an extremely luminous bipolar nebula. It is suggested that accretion onto a massive star may explain both the nineteenth century outburst and the bipolar characteristics of the mass loss nebula.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The spectral and spatial distribution of radiation from Eta Carinae. III - A high-resolution 2.2 micron map and morphological considerations of the evolutionary status does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The spectral and spatial distribution of radiation from Eta Carinae. III - A high-resolution 2.2 micron map and morphological considerations of the evolutionary status, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The spectral and spatial distribution of radiation from Eta Carinae. III - A high-resolution 2.2 micron map and morphological considerations of the evolutionary status will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-741514

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.