This page highlights some recent results from UNSWIRF. Some of this data is still being analysed in preparation for eventual publication; for further information on individual sources, please contact the person listed next to each image.

Intensity Velocity HST image of Southern Crab

The two large images above show the intensity (left) and relative velocity (right; blue - yellow corresponds to a velocity difference of ~20 km s-1) of H2 emission at 2.1218 µm in and around the proto-planetary nebula PK315+09D1, also known as He 2-104, or the "Southern Crab". These observations, made in April 1997, form part of a collaborative study with R. Sahai and J. Trauger (JPL/Caltech) of the evolution from Asymptotic Giant Branch stars to Planetary Nebulae. Our H2 imaging survey of proto-planetary nebulae with UNSWIRF complements an ongoing optical emission-line survey of these objects by Sahai and Trauger using WFPC2 on the Hubble Space Telescope. The smaller figure is a WFPC2 image of the Southern Crab, showing that there is an inner "hour-glass" structure very similar to the extended double lobes highlighted above in molecular hydrogen.

NGC 3132 3-colour image This false colour image is the result of combining and colour-coding the emission from different lines in the planetary nebula NGC 3132. Red represents emission in the 2.12 µm line of molecular hydrogen, and green shows the Brackett-gamma line of ionised hydrogen at 2.17 µm. The yellow shell therefore indicates the sharp boundary layer between ionised and molecular hydrogen, while the central star and a nearby field star appear purple. Lori Allen and John Storey are studying this and other southern planetary nebulae.

Kangaroo Nebula This image shows molecular hydrogen emission at 2.12 µm in Carina, near the Keyhole nebula. Not surprisingly, we have christened it the "Kangaroo Nebula". The total exposure time was 8 minutes, and the image is ~1.3 arcminutes across. Studies of the molecular hydrogen and CO emission from this and many other sources in Carina form the basis for Kate Brooks' PhD thesis.

M83 Br-gamma on H-alpha

The grey-scale in this plot represents the ionised hydrogen emission in the (optical) H-alpha line from H II regions (massive star formation regions) near the southwest end of the bar in the nearby southern spiral galaxy M83. The superimposed contours also show emission from ionised hydrogen, this time in the near-infrared Brackett-gamma line, showing that we have successfully imaged (for the first time ever, to the best of our knowledge) Br-gamma emission from such regions outside of a starburst nucleus. By comparing the strength of the emission in these two lines, Stuart Ryder is carrying out a study of the extinction due to dust, which should help answer such questions as whether the disks of spiral galaxies are transparent or opaque.

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Last modified: July 30, 1997.
Stuart Ryder