We report low- and high-resolution spectra of comet C/2002 C1 (Ikeya-Zhang) from the McDonald Observatory. The comet has a well-developed ion tail including CO+, CO+2, CH+, and H2O+. We used our high-resolution spectra to search for N+2. None was detected, and we placed upper limits on N+2/CO+ of 5.4×10-4. N+2 was detected in the low-resolution spectra, but we show that this emission was probably telluric in origin (if cometary, we derive N+2/CO+=5.5×10-3, still very low). We discuss the implications for the conditions in the early solar nebula of the nondetection of N+2. These depend on whether the H2O ice was deposited in the amorphous or crystalline form. If H2O was deposited in its crystalline form, the detection of CO+ but not N+2 has implications for H2O/H2 in the early solar nebula.
The Astrophysical Journal
- Pub Date:
- September 2002
- Comets: Individual: Ikeya-Zhang (C/2002 C1);
- Solar System: Formation;
- Accepted for publication in ApJ (Letters) - 10 Sept 2002