doi.eso.org

• Humphreys, Liz [European Southern Observatory (ESO)]
• Biggs, Andy [European Southern Observatory (ESO)]
• Immer, Katharina [European Southern Observatory (ESO)]
• Laing, Robert [European Southern Observatory (ESO)]
• Liu, Hauyu Baobab [European Southern Observatory (ESO)]
• Marconi, Gianni [European Southern Observatory (ESO)]
• Mroczkowski, Tony [European Southern Observatory (ESO)]
• Testi, Leonardo [European Southern Observatory (ESO)]
• Yagoubov, Pavel [European Southern Observatory (ESO)]

ALMA Band 5 (163–211 GHz) was recently commissioned and Science Verification (SV) observations were obtained in the latter half of 2016. A primary scientific focus of this band is the H₂O line at 183.3 GHz, which can be observed around 15% of the time when the precipitable water vapour is sufficiently low (< 0.5 mm). Many more lines are covered in Band 5 and can be observed for over 70% of the time on Chajnantor, requiring similar restrictions to those for ALMA Bands 4 and 6. Examples include the H₂¹⁸O line at 203 GHz, some of the bright (3–2) lines of singly and doubly deuterated forms of formaldehyde, the (2–1) lines of HCO⁺, HCN, HNC, N₂H⁺ and several of their isotopologues. A young star-forming region near the centre of the Milky Way, an evolved star also in our Galaxy, and a nearby ultraluminous infrared galaxy (ULIRG) were observed as part of the SV process and the data are briefly described. The reduced data, along with imaged data products, are now public and demonstrate the power of ALMA for high-resolution studies of H₂O and other molecules in a variety of astronomical targets.