ALMA Update

By Chris Wilson, Canadian ALMA Project Scientist
(with material from the NRAO newsletters and the ALMA web site)
(Cassiopeia – Winter 2014)

ALMA Current Status

The amazing image of HL Tau obtained by ALMA with 10+ km baselines. This image is at a wavelength of 1.3 mm and has an angular resolution of just 0.035” (5 AU at the 150 pc distance of HL Tau). The size of this disk is about 3 times the size of our solar system. Credit: ALMA (ESO/NAOJ/NRAO).

the amazing image of HL Tau obtained by ALMA with 10+ km baselines. This image is at a wavelength of 1.3 mm and has an angular resolution of just 0.035” (5 AU at the 150 pc distance of HL Tau). The size of this disk is about 3 times the size of our solar system. Credit: ALMA (ESO/NAOJ/NRAO).

ALMA construction is essentially finished. The Extension and Optimization of Capabilities (EOC) team continues to test and implement new capabilities for ALMA, including most recently high frequency (Bands 8-10) observing and long baseline observations. An important milestone was the acceptance of Total Power capabilities in November. Total power (or “single dish”) observations are important for getting information in extended sources on all spatial scales. In addition, the ALMA Pipeline is now in regular use for calibration and has also been released to the broader scientific community to use. The pipeline is part of a special CASA release 4.2.2 and is currently supported for Red Hat Linux and Mac OSX 10.8.

The 3 month dedicated Long Baseline Campaign from September through November has exceeded our expectations and produced some very exciting scientific results. One of these results, the extended protoplanetary disk HL Tau showing gaps produced by some combination of unseen planets and resonances, was the subject of a press release on November 5, 2014. The full press release is available. The other targets observed in this campaign were: a lensed galaxy at z~3, SDP.81; the evolved star Mira; the quasar 3C138 in linear polarization; and the asteroid Juno. All these Science Verification data will be released to the community for scientific exploitation; the target date for data release is January 31, 2015 (+/ 7 days).

“Revolution in Astronomy with ALMA: The Third Year”

A major ALMA meeting was held in Tokyo December 8-11, 2014. With 295 participants from 21 countries, this was a large and exciting meeting. We heard talks on everything from measuring the atmospheric properties of Mars and Io to observations of Milky-Way analog galaxies in the [CII] line and dust at redshifts of 5-7. Speaking as someone who has been involved in ALMA for over 15 years, it was extremely exciting to see such a wide range of exciting science results. I got to give the conference summary talk and it was a difficult job deciding what results to include! There was also an extremely high rate of participation by students, postdocs, and young faculty members, which bodes well for ALMA’s continuing success and scientific productivity. A conference proceedings is planned, so those who were not able to attend should be able to enjoy some of the results next year. In the meantime, many of the results are already or soon to be published, so search under ALMA using ADS or check the list of ALMA papers available via the NRAO library which lists 201 papers as of December 14, 2014.

ALMA Cycle 2 progress

Cycle 2 observing resumed December 1, 2014 after a 3 month hiatus to carry out the long baseline commissioning campaign (see above). An ALMA Cycle 2 status report is available. The report summarizes the status of Cycle 2 Early Science observations, including “Cycle 1 Transfer” projects, as of October 2014. It includes a summary of observing progress, the 12-m Array configuration schedule for the rest of Cycle 2 and a summary of the number of unfinished “high priority” observations by Band, LST and requested angular resolution. At the time the report was written, 369 hr of 12 m array observations had been obtained, with 1670 hr of A+B+Cycle 1 carryover observations remaining to be completed on the 12 m array. The median time between the data being taken and the data being delivered to the PI is about 60 days. The acceptance of the ALMA Pipeline (see above) may speed up this process.

PIs and Co-Investigators can consult the Project Tracker for information on the execution of an accepted project. PIs can also modify their user profile at the Science Portal to receive e-mail notifications whenever a component of a project is first observed, fully observed, or successfully processed.

ALMA Cycle 3 pre-announcement

The expected capabilities and timing for ALMA Cycle 3 were released last week. All 7 receiver bands will be available as well as long baselines (up to 2 km for Bands 8-10, up to 5 km for band 7, up to 10 km for Bands 3-6). Please consult the announcement for further details. The key dates for Cycle 3 are:

  • 24 March 2015: Call for Proposals for ALMA Early Science Cycle 3, release of Observing Tool, and opening of the Archive for proposal submission.
  • 23 April 2015: Proposal Deadline.
  • August 2015: Result of the proposal review process sent to PIs.
  • October 2015: Start of ALMA Cycle 3 observations.
  • September 2016: End of ALMA Cycle 3 observations.

Further Information

This will be my last regular ALMA update for E-Cass as Canadian Project scientist, so it is especially important to point out that a good source for monthly updates on the ALMA project is the electronic NRAO newsletter. And don’t forget the ALMA observatory web site which contains wide range of information about the observatory, including details about science and technology, infrastructure, geographical location. The ALMA Observatory web site has an especially good list of press releases that you can use to keep up to date on the latest hot results or to find information and images suitable for public talks.

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