Astronomy research (return)
My research at
Steward Observatory
focused on star formation in the Milky Way, and especially
in the young (about five million years old) galactic cluster
NGC 2264. This star formation region is filled with young stars, dust, and
gas.
A major advancement in understanding this cluster was made by surveying the
point sources in this region. This survey was combined with work by C.J. Lada,
Erick Young, and Tom Greene,
to produce a catalogue of 4900 detections at the V, R, I, J, H, and K photometric bands.
I built a device that could be used with existing infrared imaging camera
hardware. This device
enabled high quality polarimetric maps to be made of sources such as
Sharpless 106,
Sharpless 140, and also a region in
NGC 2264.
Using the coordinates obtained by making the multiband survey mentioned above,
the spectra of 361 sources in NGC 2264 were obtained. I wanted to determine
the spectral types of these stars, but since the spectra spanned the range
3690-6960 Angstroms, I had to extend the MK classification system to
these red wavelengths. Using
spectra published in the literature, temperature
and luminosity sensitive features were identified and this
extension was accomplished.
The hydrogen and calcium spectral lines
of the stars in NGC 2264 were often in emission, as expected for young stars
such as T Tauri stars.
Stars with absorption lines that are narrower than expected were defined as
anemic stars. It was seen that this classification
which was based purely on spectral characters also carried over to
photometric characteristics.
Furthermore, I found the dereddened SEDs could be modelled as
cases of stars surrounded by disks with holes. These simple
disk models were very successful.