Invited Presentation

ALMA Band 1

Author(s): Hiroshi Nagai (NAOJ)

Presenter: Hiroshi Nagai (NAOJ)

ALMA Band 1 is the lowest frequency band that covers 35-50 GHz. The receivers are developed by ASIAA in collaboration with NAOJ, NRAO, and NRC in Canada. The system noise temperature at the ALMA site is around 40 K at the lower end of the band and increases with frequency up to around 70 K at the higher end of the band with only minor dependence of weather condition. This excellent Tsys of ALMA provides comparable to or even better sensitivity than JVLA. After on-site commissioning started in the summer of 2022, Joint ALMA observatory started offer the Band 1 observation capability from Cycle 11. In the ongoing Cycle, we are offering most of major capabilities including polarization and 7m-Array observations. In this talk, I will review the history of Band 1 project progress as legacy and summarize the current capability. I will also highlight exciting images/spectra that were obtained from Science Verification data of W51 and Orion KL.