Science Highlight




Observatory Projects

In September 2023, the ALMA Observatory announced five filler programs that were approved on the main array. The programs were designed to fill gaps in the 12-m Array observing schedule at low frequencies in Configurations 8 and 9, based on input from scientists at the Joint ALMA Observatory (JAO) and the ALMA Regional Centers (ARCs). The proposed programs were reviewed by the Observatory Scientist and the Department of Science Operations head, and approved by the ALMA Director.

As described in the Principles of the ALMA Proposal Review Process, these Observatory Projects were initiated after verifying that the gaps in the observing queue could not be filled by any Principal Investigator (PI) submitted proposal. The Observatory Projects were awarded Grade C. While submitted as DDT projects, these projects were not charged against the 5% allocation of DDT time.

The data from the proposals is being quality assessed, i.e., it is checked for problems in the representative spectral windows. After this assessment, the data will be released through the ALMA Archive with no proprietary period. The release of Observatory Project data will be preceded by an announcement on the Science Portal.

The programs are listed in the following Table:


PID Title Description Primary Articles
2022.A.00032.S 12CO and Band 3 continuum 5-pc-scale imaging of molecular clouds in the Antennae galaxies The  Antennae galaxies  (NGC  4038/4039)  are  one  of  the  nearest  and  the  most  famous  merging  galaxy  pair and serves as an ideal subject for the investigation of super-giant molecular clouds (S-GMCs; mass>106 M, size ∼50 pc). The existing highest angular resolution CO(1–0) data in the archive is 2018.1.00272.S (0.55 arcsec (∼58 pc) beam; only for the ”Overlap”. This project aims to observe CO(1–0) emission from this galaxy pair with 0.05 arcsec resolution (∼5 pc) to probe molecular cloud properties.  
2022.A.00034.S Band 3 observations of a super-deep 1'x1' field in Hubble Deep Field South The HDF-S field has many orbits of HST data as well as optical/NIR followup, but almost no coverage from ALMA. Observing a blank field inside HDF-S that goes deeper than any existing sub-mm observations in the more subscribed fields could motivate the community to apply in the future for observations in this range of hour angles, and will add value to existing optical and NIR observations.  Having a sub-mm flux measurement or even flux upper limit could help studies of galaxy number counts, spectral energy distribution fitting, or simply providing high redshift galaxy targets to follow-up. This project observes a mosaic of five pointings in the deepest region of HDF-S, which will cover an area of ~2.5 arcmin2, dowwn to a sensitivity of ~5 μJy in continuum.  
2022.A.00036.S Band 3 high-spectral resolution survey of HL Tau The upcoming Wideband Sensitivity Upgrade will greatly enhance ALMA's capabilities. This Band-3 survey of the protoplanetary disk HL Tau uses 32 spectral setups (15360 channels, 470MHz bandwidth, and 45min on-source integration each) to roughly emulate how a single spectral setup of a future WSU project might take advantage of the upgraded correlated bandwidth, IF range, and spectral resolution. The dataset allows for multiple pathfinder stress tests for internal ALMA subsystems. It should be noted that the Maximum Recoverable Scale for these observations is significantly smaller than the known Largest Angular Scale of spectral line emission toward HL Tau.  
2022.A.00035.S Band 1 Continuum and CS line observations of HD 163296 In the last decade ALMA has revolutionised the study of protoplanetary disks through observations mostly in band 3, 6 and 7. This project observes HD 163296, a benchmark (and the brightest) system for the community. By demonstrating Band 1 capabilities in resolving dust structure and detecting lines from important molecular species, these observations will trigger future high resolution, low frequency ALMA observations that build on this result both in HD163296 and in other disks.  
2022.A.00037.S Band 1 Continuum and CS line observations of HL Tau Same as project 2022.A.00035.S towards the iconic source HL Tau.