Results with the ATCA 3mm Prototype System (July 2001)

HCO⁺ absorption in the galaxy Centaurus A

The HCN (1-0), HCO⁺ (1-0), and HNC (1-0) spectra displayed below have been observed in July 2001 with the one baseline (CA03-CA04: 30m, 2 pol) 3mm prototype system of the Australia Telescope Compact Array.
The HCN (1-0), HCO⁺ (1-0) and HNC (1-0) rest frequencies are 88.6304157, 89.188518 and 90.663543 GHz, respectively.
On July 11, 2001, we observed HCO⁺ (1-0) and HCN (1-0) simultaneously using two IFs with 64 MHz bandwidth each, divided into 128 channels (config ant234ac_64_128_2p-2f).

• Calibrated HCO⁺ absorption spectrum (narrow-band). The absorption complex (537 - 625 km/s) is resolved into numerous components. The centre frequency is 89.010 GHz. The total integration time on-source is 204 min.
• Calibrated HNC⁺ absorption spectrum (narrow-band). The absorption complex (... km/s) is resolved into numerous components. The centre frequency is 90.485 GHz.
• Calibrated HCN⁺ absorption spectrum (narrow-band). The absorption complex (... km/s) is resolved into numerous components. The centre frequency is 88.450 GHz.

See also

• A Supermassive Black Hole in a Nearby Galaxy: ISAAC Inspects the Center of Centaurus A
• Wiklind & Combes 1997