ALMA Programme News

Save the date - ALMA Development Stuides Workshop

Contribution: ESO Development Team

In order to keep ALMA at the forefront of technology, all ALMA partners have a continuous development programme. ESO strives to closely involve the member state institutes in this programme by issuing calls for development studies every three years (see the  ALMA European Development webpage). The next call is expected to be issued in 2019. To optimally develop the ideas for new studies – especially in the context of the ALMA development roadmap – ESO will organise a development study workshop at ESO Garching in June (3-5); further details will be announced soon. Save the date.

First steps to 'longer' ALMA baselines: Testing campaign October 2018 

Contribution: Neil Phillips

An ESO development study is investigating the feasibility of a simple extension of ALMA to longer baselines. The existing ALMA system is engineered to support the current largest configurations, giving maximum baselines of 16km, but there is the potential to use baselines up to around a factor of two longer with minimal software/firmware tweaks. An obvious stepping stone to a longer baseline ALMA is to perform interferometry between the AOS and OSF sites, separated by around 30km horizontally and 2km vertically. In addition to validating the ability to operate longer baselines, an AOSxOSF interferometer will also provide a testbed for investigating and improving calibration of long baseline observations. The OSF site already has working antenna stations, and there are spare communication fibres between the two sites over which antennas can be connected. Brief tests were performed of such connectivity in 2012 with positive outcome, but much more thorough testing is needed.

With extensive support from JAO engineering and computing teams, a first test mission for this study was conducted from October 16 to 26 (2018). The focus at this stage was on the impact of long fibre lengths. Two AOS antennas, CM07 and PM04, were connected over the 30km AOS-OSF communication fibres to correlator, central LO and computing resources (STE) at OSF. The independent OSF resources meant that an extensive period of testing could be performed without interrupting science operations. A major concern of using such long fibres (and many connections) was how reliably the receivers would lock with the attenuated LO signal. It was also necessary to confirm that time synchronisation of the antenna devices could be reliably maintained and that the digital transmission system could reliably deliver data to the correlator.

The outcome of this mission was very positive. After ironing-out various hardware and software configuration issues everything functioned entirely normally. No problems were found with either time synchronisation or receiver locking after extensive testing. The digital transmission system worked reliably, although was really on the limit of optical power (this can be improved with better connections in future). Most importantly, an interferometer was established and interferometric calibration observations could be performed as normal. All receiver bands were successfully locked in both antennas at multiple frequencies, and the interferometer coherence confirmed the stable locking. A bi-product of the test mission was demonstration of successful observations with a Cycle-7 pre-release online software environment, including a significant operating system upgrade.

Now that reliable operation of antennas over the AOS-OSF communication fibres has been confirmed, a next mission for the study will test interferometry between a pair of antennas at the two sites, i.e. a 30km baseline. Some minor software and firmware updates are needed to support these actual long baseline tests. To allow delay tracking with a 30km baseline means allowing a higher rate of delay adjustments by the digitiser clock generators in the antennas, and also an increase in the "causality delay" offset in the control software.

Contributions from the ARC Nodes

ALLEGRO: Netherlands ALMA Science Day

Summary: The second Netherlands ALMA Science Day took place on November 1st, 2018, in Leiden Observatory. Allegro organized this meeting for the Netherlands ALMA community to share their exciting new science and to learn of news from the telescope. 

We had in total more than 50 participants, with people coming from Amsterdam, Groningen, and Leiden and with a whole diversity of science, from proto-planetary disks to AGNs. Martin Zwaan (ESO) also attended and gave us an update on ALMA and the plans for the next 10 to 15 years of the telescope. 

In addition, for the interested attendees a second training session on the 2nd of November 2018 was arranged for CASA data reduction and training. This consisted of lectures, on calibration and imagining, followed by a hands-on tutorial on self-calibration. 

We had over 25 people attending the training, from beginners all the way to experts that had very specific questions on how to improve the quality of their data.

Both events were very successful and our PIs were very happy with the discussions and the training day. We are already looking forward to organizing the third Netherlands ALMA Science Day next year. 

German ARC: Interactive Proposal Preparation Support

Enjoy ALMA outreach and proposal preparation support conveniently at your home institution!

As a service to the local astronomical community, the German ARC node organizes a series of ALMA proposal preparation and outreach tutorials as video sessions using zoom, which the participants can join without charge and from a variety of platforms. The training sessions will cater to astronomers with different levels of expertise, ranging from an introduction to the necessary terminology for non-radio astronomers to a concise update of ALMA's capabilities in Cycle 7 for experienced ALMA users. Participants in the sessions and other prospective ALMA users are very welcome to follow up their training in one-on-one chats with experienced ARC node staff and/or by visiting the node for further face-to-face interaction and one-on-one help with their proposals.

The tutorials will be held in late March and early April 2019. The exact dates will be announced shortly after the Call for Proposals. Notices of intent to particpate are much appreciated and will be taken into account in the scheduling.

For informal inquiries and/or notices of intent, please contact arc[at]astro.uni-bonn.de

German ARC: Training opportunity - "Radio Interferometry - Methods and Science"

Now in its eighth year of operations, ALMA produces on average about 700 GB/night of high-quality astronomical data. While the investigative teams of successful ALMA projects are busy with the primary goals of their proposals, the ALMA archive turns into a goldmine for those knowledgeable in the art and craft of radio interferometry. 

The Master-level course "Radio Interferometry: Methods and Science", organized and conducted by the German ARC node, offers hands-on training in the data reduction and analysis of interferometric data for Master students, PhD students and senior astronomers. The course starts with a brief review of the basic concepts of radio interferometry including calibration and imaging. Then the various steps necessary to create fully calibrated data cubes from interferometric raw data are discussed. Already during the lectures, the participants can practice the individual steps on their copy of an ALMA data set, using powerful computing servers and the versatile Common Astronomy Software Applications (CASA) package. In the final sessions, the participants learn how to analyze their interferometric data and what additional considerations are required for special research topics like polarization studies.

The German ARC node offers remote access to the course via a dedicated zoom video session, which the participants can join without charge and from a variety of platforms. If you would like to follow the course at your home institution, please contact us before 15 March 2019 at arc[at]astro.uni-bonn.de.

For more information, please see the course homepage and/or contact arc[at]astro.uni-bonn.de. 

Image Credit: XKCD 

Upcoming ALMA or ALMA-related Meetings

• New Horizons in Planetary Systems
  13-17 May, 2019, Victoria, BC - USA
  The 2019 meeting “New Horizons in Planetary Systems” is a science conference jointly organized by NRC Herzberg in Victoria, BC and NRAO in Charlottesville, VA under the auspices of the NAASC (North American ALMA Science Center). This meeting will have a broad scope, including planetary systems in formation within protoplanetary disks, minor objects in the solar system, debris disks and exoplanets, with a focus on, but not limited to, ALMA observations and/or talks related to areas of ALMA observations

• Workshop on Polarization in Protoplanetary Disks and Jets
  20-24 May, 2019, Sant Cugat del Valls, Catalonia, Spain
  The study of the formation and evolution of protoplanetary disks around young stars saw a tremendous boost by the advent of ALMA and the development of new capabilities in the infrared and radio telescopes, thanks to the huge combined improvement in sensitivity, angular resolution, and image fidelity. However, the role of magnetic fields in the formation and evolution of disks around young stars is still a poorly understood topic. Are protoplanetary disks and protostellar jets magnetized? Polarimetric observations are the primary means to obtain information regarding the magnetic fields. However, this technique can be hampered by other polarization mechanisms such as dust self-scattering, radiation alignment of aspherical grains or anisotropic resonant scattering of linear polarization of molecular lines. The main goal of this focused meeting is to bring together observers and theoreticians interested in the study of magnetic fields in protoplanetary disks and protostellar jets as well as polarization mechanisms to review the current state of the research and explore effective means to probe magnetic fields.

• IAU Symposium 352: Uncovering early galaxy evolution in the ALMA and JWST era
  3-7 June, 2019, Viana do Castelo, Portugal
  Thanks to deep observations in the last few decades with the Hubble Space Telescope, the Spitzer Space Telescope, and ground-based 8–10-metre class telescopes, we know more about the young Universe than ever before, having reached tantalisingly close to the dark ages and the formation of the first stars and galaxies. It is now well established that the rate of cosmic star formation rose rapidly from the epoch of reionization to a maximum at z~2. The first three billion years of cosmic time were therefore the prime epoch of galaxy formation. Characterising galaxies at this epoch, both observationally and theoretically, is thus crucial to achieve a major goal of modern astrophysics: to understand how galaxies such as our Milky Way emerged from the primordial density fluctuations in the early Universe and evolved through cosmic time. Recent major international investments in facilities such as the Atacama Large Millimetre Array and the James Webb Space Telescope (JWST) promise to shed light on these questions.

• Views on the Interstellar Medium in galaxies in the ALMA era
  2-6 September, 2019, Bologna, Italy
  The advent of the power of the Atacama Large Millimeter Array and the upgraded capabilities of other sub-mm/mm facilities are now opening a complete new window of the baryon cycle. On one hand, local galaxies are exploited as 'laboratories' where the interstellar medium is studied down to molecular cloud scales and the physical processes can be investigated in detail. On the other hand, thanks to the unprecedented sensitivities of the new facilities, systematic surveys of the gaseous content in high redshift galaxies are starting to characterize the gas cycle throughout cosmic time. Dedicated observations have revealed gas in the most distant galaxies, all the way to the reionization epoch, and have started to dissect the interplay between luminous active galactic nuclei and their host galaxy. These new observational constraints are guiding the next generation of galaxy evolution models.