Spectral Evolution Animations

While I was bored observing one night, I put together the following "morphs" of low resolution, near-infrared spectra spanning types L and T. The following files are quicktime .mov files, and are intended for educational use only.

Spectral "morph" for types L0-T8

Linear (sliding) scale: [large format (4.2 Mb)] [small format (0.7 Mb)]
Logarithmic scale: [large format (2.2 Mb)] [small format (0.3 Mb)]
Temporal evolution of a 0.05 M_sol mass brown dwarf spectrum from 0.3 to 7.3 Gyr

Linear (sliding) scale: [large format (6.3 Mb)] [small format (1.0 Mb)]
Logarithmic scale: [large format (4.6 Mb)] [small format (0.6 Mb)]

How were these put together?

The L and T dwarf spectra were are all obtained with the SpeX spectrograph in its lowest resolution mode. The spectra were flux calibrated using the absolute K-band/spectral type relation in Burgasser (2007) and interpolated onto a common wavelength scale. Intermediate spectra between the individual sources were then determined by linear interpolation in steps of 0.1 subtypes. This provided the spectral morphological evolution plots in the first set of animations.

The temporal evolution plots were made by assigning bolometric magnitudes to each spectral type using a relation from Burgasser (2007) and associated ages from the evolutionary models of Burrows et al. (1997), assuming a mass of 0.05 M_sol. The interpolation of the spectra were then determined following a linear age spacing of 50 Myr. Notice the slow down at the end of the T sequence!

The spectral plots were originally made as encapsulated postscript files using IDL code, then stitched together into a quicktime movie file using Graphic Converter.

Last updated 7 April 2007 by Adam Burgasser

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