Fred K.Y. Lo
With Early Science underway on the EVLA and ALMA, the National Radio Astronomy Observatory (NRAO) is delivering transformational scientific capabilities to the community via a suite of four world-class telescopes, thereby enabling the US (and international) astronomy community to make new discoveries and answer outstanding fundamental astrophysical questions underlying the science objectives described in the Astro2010 Decadal Survey report, New Worlds, New Horizons in Astronomy and Astrophysics (NWNH).
The NRAO suite of telescopes includes: the international Atacama Large Millimeter/submillimeter Array (ALMA), the Expanded Very Large Array (EVLA), the Robert C. Byrd Green Bank Telescope (GBT), and the Very Long Baseline Array (VLBA). Each telescope is the world leader in its observing domain. Collectively, these telescopes will enable astronomers to observe from sub-millimeter to meter wavelengths with an order of magnitude or more improvement over current capabilities in resolution, sensitivity, frequency coverage, or field of view. Used individually or in combination, the NRAO telescopes will provide the novel capabilities required to address many of the science themes outlined in NWNH, such as placing constraints on the nature of Dark Energy, imaging the first galaxies in the epoch of reionization, and observing directly the formation of planets in proto-planetary disks.
ALMA will provide for the first time detailed images of stars and planets in formation, young galaxies being assembled throughout the cosmic history of star formation, and generally open new windows into the cold Universe via the tremendous increase in sensitivity and resolution at millimeter and submillimeter wavelengths. The US astronomy community's strong anticipation for ALMA was demonstrated by the more than 7:1 oversubscription for observing time in the first Early Science opportunity. As you read this message, the first ALMA Early Science data packages have been delivered to investigators. ALMA full science operations is expected within another two years according to plan.
At the adjacent centimeter-wavelength range, the EVLA scientific capabilities are comparable to those of ALMA, but exceed those of the Very Large Array by one to four orders of magnitude, depending on the parameter. EVLA construction is on schedule and on budget, while meeting its technical specifications and scientific objectives. Even as construction is ongoing, Early Science programs have started in early 2010. Already, a special issue of the Astrophysical Journal Letters devoted to EVLA Early Science results was published in September 2011, describing cutting-edge research from the Solar System to the farthest reaches of the Universe. In late 2012, the completed EVLA will transition to full science operation as the world’s most capable and versatile centimeter-wave imaging array.
With comparable collecting area and sensitivity to ALMA and EVLA, the 100m GBT is the preeminent filled-aperture radio telescope operating at meter to millimeter wavelengths. Its more than 2-acre collecting area, unblocked aperture, and excellent surface accuracy enable precision pulsar timing to detect gravitational wave radiation, testing the strong field limit of General Relativity, mapping the gas inflow into galaxies, detecting 21 cm HI emission at z~1 via the novel Intensity Mapping approach, revealing the merging process of clusters, and probing the chemistry of the Universe. Based on an affordable plan driven by key science projects, the GBT is being augmented by new cameras that can greatly increase imaging speed and significantly enhance its science impact in the coming decade.
The VLBA is the premier fully dedicated VLBI array in the world. Astrometry with the VLBA has reached the precision of a few micro-arcseconds, enabling distance and proper motion measurements of objects in the solar neighborhood, across the Milky Way, within the Local Group, and moving with the Hubble flow. Its scientific capabilities continue to improve as a major bandwidth expansion to increase sensitivity is completed by January and new C-band receivers are installed by September 2012. I should also point out that scientifically the VLBA is comparable but complementary to the Gaia mission to be flown in 2013. When VLBA is used in conjunction with the phased EVLA and the GBT, the resultant High Sensitivity Array greatly enhances the sensitivity for VLBI observations and broadens the range of novel scientific research. To place future VLBA operations on a solid footing, we are developing a new operating model to incorporate the US and international partners for its operation and development according to five-year plans.
Looking towards the future, we are also focusing on developing forefront technology. Taking advantage of the outstanding technical expertise across NRAO that has kept our facilities at the forefront, the Coordinated Development Lab (CDL) oversees a science-driven program aiming to help realize key NWNH science goals, such as the detection of gravitational waves via pulsar timing (NANOGrav), the study of the epoch of reionization via the highly redshifted 21 cm HI line (PAPER/HERA), the development of the Frequency Agile Solar Radiotelescope (FASR), and prepare for other next generation facilities.
In order to carry out the myriad of tasks under realistic budgets, the NRAO continues to refine the most cost effective operating model, the ‘One Observatory’ approach, based on Observatory-wide planning, prioritization and coordination to utilize optimally the collective expertise and resources. More details about the current status and future plans of the NRAO can be found in the NRAO Long Range Plan.
Currently, the US and world economies are struggling and there are budgetary pressures at all levels. Clearly the ambition of astronomers must be tempered by the budget realities. So, I urge everyone in the astronomy community to actively participate in the NSF-AST Portfolio Review that is now underway. This Review’s goal is to recommend how support for all existing AST facilities, programs, and activities should be prioritized and interleaved with new initiatives recommended by the Astro2010 Decadal Survey, within the limitation of realistic future budgets. The outcome of this Review will result in significant near-future changes to the structure and capabilities of US astronomy, and thus it deserves everyone’s attention.
The NSF-AST has now explicitly invited community input to the Portfolio Review Committee and the NSF staff, and a description of the types of community input being sought is available online. The input window is open until 31 January 2012. A recent update of the NSF-AST budget and planning status is available via a briefing presented by Director James Ulvestad to the Astronomy and Astrophysics Advisory Committee at their October 2011 meeting.
While a periodic portfolio review is obviously a prudent exercise, it is important to examine the premise of the Portfolio Review, in order to avoid decisions that might lead inadvertently to irreparable damage to the competitiveness of the US astronomy enterprise. So, this is a critical time for the voices of the community to be heard by our funding agency.
The NRAO has created an online forum for discussing the community’s priorities, concerns, and issues with respect to the Portfolio Review and the Observatory. If you would prefer to provide a direct private input to the NRAO, please e-mail us at email@example.com. Input received via this address will be available only to the NRAO senior management team.
After more than five decades of continual improvement, NRAO comprises the nation’s core competency in radio astronomy, an invaluable resource for the astronomy community in the US, and indeed the world. We will work together with the community to meet our budget challenges and continue to enable forefront research into the Universe at radio wavelengths.
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