ALMA Update

1. The First Year of ALMA Science

A conference on “The First Year of ALMA Science” was held December 12-15, 2012 in Puerto Varas, Chile. The conference covered all the topics covered by Early Science observations, from observations of Solar System bodies to the high redshift Universe. Many of the presentations should soon be available on the conference web site and there will also be proceedings from this conference. More information can be found on the conference web site at http://www.almasc.org/2012/

On a personal note, I attended the meeting and found it incredibly exciting to see such a wide variety of results from ALMA. Some of the images were so spectacular it was hard to distinguish the data from the models. I was particularly impressed by the first images of protostellar and transitional disks, which showed unusual features such as “peanut”-shaped asymmetric dust emission (interpreted as arising in gas asymmetries due to an orbiting planet) and a beautiful movie of an inclined, flared disk which showed emission from both the top and the bottom sides of the disk! There was also a spectacular mosaic shown of a 100,000 solar mass cloud know as “The Brick” which is 100 pc from the Galactic Centre and roughly 3 pc in size, where dense gas tracers reveal a network of filaments and cores. At higher redshifts, [CII] emission from a redshift 4 system detected the quasar, a neighboring submillimeter galaxy, a bridge of emission between them, and, for good measure, [CII] from a couple of Lyman Alpha Emitters.

Figure 1: The rotating circumstellar disk around the Herbig Ae star HD163296, observed in the J=3-2 line of CO by ALMA. The contours outline the first moment intensity map of the emission. This data set was the subject of several talks and posters at “The First Year of ALMA Science”, including an amazing one by Itziar de Gregorio-Monsalvo, which included  a movie in velocity space showing that CO emission from the top and bottom sides of the flared disk. This image is taken from the NRAO enews, Volume 5, issue 11.

There will be an ALMA special session on Tuesday, January 8 at the Long Beach meeting of the American Astronomical Society. This Special Session will take place after one year of ALMA Early Science Operations and will be an ideal forum to present the highlights of the first year of ALMA science operations.

2. New ALMA papers since my last update

There are now enough ALMA papers and projects in progress that I am switching to giving an update of recent papers, rather than a complete list. See my Fall update for the first 11 ALMA data papers.

  1. Swinbank et al. 2012, “An ALMA survey of Sub-millimetre Galaxies in the Extended Chandra Deep Field South: Detection of [C II] at z=4.4”, MNRAS, 427, 1066
  2. Galvin-Madrid et al., 2012, “ALMA and VLA observations of recombination lines and continuum toward the Becklin-Neugebauer object in Orion”, A&A, 547, 58
  3. Niederhofer et al., 2012, “Outflow structure and velocity field of Orion source. I. ALMA imaging of SiO isotopologue maser and thermal emission”, A&A, 548, 69
  4. Ricci et al., 2012, “ALMA Observations of ρ-Oph 102: Grain Growth and Molecular Gas in the Disk around a Young Brown Dwarf”, ApJ, 761, L20
  5. Wang et al., 2012, “ALMA Submillimeter Continuum Imaging of the Host Galaxies of GRB 021004 and GRB 080607”, ApJ, 761, L32
  6. Persson et al., 2012, “Warm water deuterium fractionation in IRAS 16293-2422. The high-resolution ALMA and SMA view”, A&A, 549, L3
  7. Kristensen et al., 2012, “ALMA CO J=6-5 observations of IRAS16293-2422: Shocks and entrainment”, A&A, in press
  8. MacGregor et al., 2012, “Millimeter Emission Structure in the first ALMA Image of the AU Mic Debris Disk”, ApJ, in press
  9. Loinard et al., 2012, “ALMA and VLA observations of the outflows in IRAS 16293-2422”, MNRAS, in press

Many of these results were presented at the recent meeting, “The First Year of ALMA Science” in Puerto Varas, Chile, as well as additional new results for which a paper is in progress or listed as submitted on the ArXiV.  There is clearly a lot of work in progress on new ALMA data!

3. ALMA Cycle 1 Results

The results for ALMA Early Science Cycle 1 became available in late November. There are 196 high priority science programs covering a wide range of science topics, from the solar system to high-redshift galaxies. A complete list of the highest priority projects is available at https://almascience.nrao.edu/news/alma-early-science-cycle-1-outcome-of-the-proposal-review-process

Cycle 1 observations will begin in January, 2013

Canadian astronomers were very successful in obtaining highest priority time on ALMA during the Cycle 1 proposal process. Six proposals with Canadian PIs were given highest priority status; this represents nearly 4% of the total time awarded on ALMA. Including projects with Canadian co-Is, A further 18 projects with Canadian Co-Is were awarded highest priority status. These proposals represent 18% of the high-priority time with ALMA and represent 22 individuals from 10 institutions. For comparison, Canada's global "share" of ALMA operations costs  is about 2.8%.

Participants at the conference “The First Year of ALMA Science” heard a preview of the likely capabilities for ALMA in Cycle 2. The anticipated capabilities include baselines up to 2 km, 40 antennas for receiver bands 3, 6, 7, and 9 (3 mm, 1.3 mm, 0.8 mm, and 0.45 mm), at least 20 antennas for the new receiver bands 4 (2 mm) and 8 (0.6 mm), and on-axis polarization capability. Final details should be available by my next ALMA update.

4. ALMA Early Science Cycle 0 Progress and Science Verification

An update on the progress with Cycle 0 observing was posted October 8, 2012 and is available at https://almascience.nrao.edu/news/update-on-alma-cycle-0-observations Although most of the highest priority programs from Cycle 0 will be completed, there are some RA ranges and weather bands (particularly Band 9) for which it will not be possible to complete all the programs.

Two new Science Verification data sets have been released. The first is Band 6 and 7 (1.3 mm and 850 micron) observations of the protoplanetary disk HD163296 containing many spectral lines. The second is Band 3 (3 mm) recombination line observations of the Galactic Centre.

The ALMA archive is now open and populated with the first few Cycle 0 data sets. More data will be uploaded as additional data passes the 1 year proprietary period deadline (note that this deadline runs from the delivery to the PI, and not the date the data were observed).

5. ALMA Construction Progress

Pierre Cox has been appointed as the next Director of ALMA. He will take up the position on 1 April 2013, for a period of five years, at the end of Thijs de Graauw’s term as ALMA Director. Thijs de Graauw, who has been the ALMA Director since 2008, has taken the observatory past many milestones in his five-year term, including the start of early science observations in 2011.

As of early November, there were 46 antennas at the 5000 m Array Operations Site (AOS), out of the final complement of 66. Over 50 antennas have been accepted, tested, and taken up to the AOS. Commissioning is continuing with a focus on modes needed for Cycle 1, such as mosaics with 150 pointings, and on the newly completed 64 station, 4 quadrant correlator. First fringes have been obtained with the Band 5 (163-211 GHz) receivers. Science targets in this band include the J=4-3 SiO maser (which was detected toward VY C Ma and W Hya), the low-energy water line at 183 GHz, and [C II] redshifted from early galaxies at z~10. The first complement of six Band 5 receivers come from a project funded through the European Union. Connection of the multi-fuel Permanent Power Supply (PPS) at the AOS has begun. This will enable use of antenna stations previously unoccupied, including many on the longer baselines that will be a feature of Cycle 1 Early Science. However, Cycle 1 is expected to begin with the array in a compact configuration.

Participants at the conference “The First Year of ALMA Science” heard an update on the current status of ALMA development projects. There are four projects at varying levels of approval by the ALMA Board, plus many additional projects undergoing design studies. The four current projects are: completing the suite of Band 5 (1.8 mm) receivers; connecting the observing site to the Chilean internet backbone using fiber optic cable; enabling VLBI capabilities for ALMA; constructing a prototype receiver for Band 1 (7 mm).

Figure 2: The 24th North American antenna leaves the antenna erection compound at the ALMA site in northern Chile to be outfitted with ALMA electronics. This image is taken from the NRAO eNews, Volume 5, issue 10.

6. Further Information

A good source for monthly updates on the ALMA project is the electronic NRAO newsletter

http://science.nrao.edu/enews/. And don't forget the ALMA observatory web site http://www.almaobservatory.org/ which contains wide range of information about the observatory, including details about science and technology, infrastructure, geographical location.

An email list has been created for Canadian astronomers interested in ALMA.  This moderated list will periodically send out updates on ALMA's status, news of software releases, notices of upcoming ALMA science meetings and workshops, etc., which would be of interest to Canadian astronomers. Those who wish to be subscribe to the alma-users list are encouraged to visit the web page

http://lists.astrosci.ca/mailman/listinfo/alma-users or send an email to Gerald.Schieven(at)nrc-cnrc.gc.ca.

Chris Wilson wilson@physics.mcmaster.ca

Canadian ALMA Project Scientist

(with material from Gerald Schieven, and the NRAO newsletters)