Diamonds and PAHs in the Circumstellar Environment of the Herbig Ae / Be Star Elias 1

We report long-slit spectroscopic observations of the Herbig Ae/Be star Elias 1 in the 3.2 3.6μm region covering the C-H stretch emission features of hydrogen-terminated diamonds and PAHs. The data were recorded at UKIRT using UIST and yield information on the profiles and intensities of the bands as a function of offset along the N-S and E-W axes centred on the close binary. The diamond and nearby IR continuum emission arises from a symmetrical inner core region (6 0.34 or 48 AU). The 3.3μm PAH emission is extended along the E-W axis up to c. 100 AU each side of the star. This result supports a suggestion of Haas, Leinert & Richichi (1997) of an E-W oriented bipolar nebula in Elias 1.