2007 Annual Science Report

NASA Goddard Space Flight Center Reporting  |  JUL 2006 – JUN 2007

The Evolution of Organics in Space

Project Summary

Understanding the nature of the natal interstellar cloud is crucial to understanding the chemistry of the solar nebula, and hence the chemistry of the Sun and planets. Since that cloud no longer exists, it is necessary to study the cores of existing dense interstellar clouds where stars are forming. Moreover, since the physical conditions vary among and within such clouds, it is important to investigate the chemical and physical processes in a variety of such environments.

4 Institutions
3 Teams
0 Publications
0 Field Sites
Field Sites

Project Progress

Molecules in Interstellar Cloud Cores:

Understanding the nature of the natal interstellar cloud is crucial to understanding the chemistry of the solar nebula, and hence the chemistry of the Sun and planets. Since that cloud no longer exists, it is necessary to study the cores of existing dense interstellar clouds where stars are forming. Moreover, since the physical conditions vary among and within such clouds, it is important to investigate the chemical and physical processes in a variety of such environments.
Irvine and colleagues in Korea have been studying chemical tracers of the chemical and physical state of interstellar molecular clouds. The center of our Milky Way Galaxy is an environment where various energetic processes influence the chemical composition of such clouds, and overlapping clouds in the line of sight complicate the situation. Our observations of HNCO emission in the Galactic Center find evidence for an enhanced abundance of this species in an expanding ring of material that seems to be colliding with the principal Sgr B2 cloud and triggering sequential star formation. Since HNCO is thought to form when the OCN- ion is liberated from icy grain mantles by shocks, HNCO may prove to be a useful tracer of such shock processes (Minh and Irvine, 2006).

Leadership Activities Related to Astrobiology:

Irvine attended the General Assembly of the International Union in August 2006. He was elected Vice-President of IAU Commission 51 (Bioastronomy).
A significant part of Irvine’s activities as co-Investigator in the Goddard Center for Astrobiology concerned his role as Chair of the Scientific Organizing Committee for the up-coming conference “BioAstronomy 2007”, sponsored by IAU Commission 51. These activities included establishing a general outline for the conference, identifying and contacting invited speakers, correlating all significant decisions with the rest of the Scientific Organizing Committee, reading all 175 submitted abstracts and tentatively distributing them by conference session and into either oral or poster contributions, consulting on an invited public lecture and on other evening or excursion activities, and planning the detailed conference schedule. The Conference was held in San Juan, Puerto Rico, 16-20 July 2007, and was widely attended by members of the astrobiology community.

The Large Millimeter Telescope (LMT) is a joint project of the University of Massachusetts Amherst and the Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) in Tonantzintla, Puebla, Mexico. The LMT will be the largest single-dish telescope in the world operating at short millimeter wavelengths when it is completed in 2008-09. It will be a powerful instrument for various fields within astrobiology, including the study of the chemistry and physics of comets, other primitive bodies in the solar system, planetary and satellite atmospheres, and the interstellar medium. Irvine continued as a member of the Science Working Group for the Large Millimeter Telescope Observatory (LMTO), the US-Mexican organization that will operate the LMT. Activities include twice-weekly telecons on the status and plans for the telescope. In addition, Irvine has been appointed as Special Assistant to the Vice-Provost for Research at the University of Massachusetts Amherst, with responsibility for promoting closer cooperation between the US and Mexican teams working on the project. This includes specifically collaborating with the legal teams from each side to construct the final legal agreement and MOUs defining the organization that will operate the telescope.

{{ 1 }}

In November 2006, Irvine helped to organize the official Inauguration of the LMT, a weeklong series of talks and excursions scheduled to honor the support given to the project by Mexican President Vicente Fox. The President observed first light at 12 GHz, which is substantially below the planned operating frequencies of the completed telescope. Subsequently, Irvine helped to organize an independent technical review of the status of the LMT and the tasks needed to bring it into true operation, as mandated by University of Massachusetts Chancellor John Lombardi and INAOE General Director Jose Guichard. This review took place during the entire week of 12-16 March 2007.

Now (August 2007), the telescope alidade and back-structure are complete, three of the five rings of surface panels have been installed, the telescope drive system has demonstrated the ability to track an astronomical source, and most of the associated facilities (electrical, communications, etc.) are in place. The major challenges are bringing the surface to the specified accuracy (rms metrology), procuring and testing the outer two rings of surface panels, and installing capable actuators for the active surface. The initial instrumentation for the telescope is mostly complete: SEQUOIA, a 32-element heterodyne array for observations at 3-mm; AzTEC, a 144-element bolometer array for observations at 1- and 2-mm; a very broad-band heterodyne receiver (36 GHz instantaneous bandwidth) at 3-mm wavelength, intended to measure the redshift of distant galaxies and the shape of planetary absorption lines; and a 4-element heterodyne SIS receiver for operation at 1-mm. SEQUOIA and AzTEC have been extensively tested and used on smaller radio telescopes, the broadband 3-mm receiver is undergoing initial testing at the UMass 14-m telescope in Massachusetts, and the 1-mm receiver is under construction.

It is hoped that the LMT surface will be completed by early 2008, so that commissioning can begin during that year. Commissioning activities will include setting the surface with the aid of holography, tuning the active surface for gravitational and thermal effects, determining the telescope pointing, implementing the full servo-system, and integrating the instruments into the system.
Irvine is working to insure that the telescope will indeed be a powerful instrument for research in astrobiology.

Education and Outreach:

Irvine continued to participate in the University of Massachusetts interdisciplinary course for non-science honors students entitled “Cosmos to Humanity: From the Big Bang to the Space Age”. The theme of the course is astrobiology/evolution, beginning with the evolution of the universe and continuing with the formation and evolution of the solar system, the origin and evolution of life, life in extreme environments, the evolution of complex life, the origin and evolution of humans, and the search for life elsewhere in the universe. Irvine continued development of several lectures with associated reading material and web-based units on the topics of cosmology, nucleosynthesis, organic matter in galaxies, the origin of the solar system, environments in the solar system for life, and extrasolar planets and the search for life in the universe.

Future Plans – Observations of comets:

Although intended primarily for extragalactic observations, the AzTEC array is a powerful mm-wavelength camera (intended for use on the LMT) that can be used for mapping dust emission from cometary comae. It has been tested extensively at the James Clerk Maxwell Telescope (JCMT) in Hawaii. Following a successful two-week engineering run in July 2005, AzTEC conducted a two-month series of 1100 μm surveys for “sub-millimeter galaxies”. The performance of the new science detector array was excellent, and the sensitivity goal was met or exceeded for most projects. As the LMT is not scheduled to be ready for AzTEC operations until late 2008, the University of Massachusetts has arranged an ambitious two-year visiting instrument program at the Atacama Submillimeter Telescope Experiment (ASTE). ASTE is a Japanese-run, 10-m diameter telescope located on Pampa La Bola, near Cerro Chajnantor – the location for the Atacama Large Millimeter/submillimeter Array (ALMA) in northern Chile. The AzTEC/ASTE team is a multi-national group composed of astronomers from UMass, Mexico, the National Astronomical Observatory in Japan (NAOJ) and the University of Tokyo. There is an agreement that AzTEC will remain at the ASTE telescope through 2008 and then go to the LMT to begin 2-mm wavelength operations from the much larger dish.
If a bright comet appears while AzTEC is on the ASTE, an effort will be made by the UMass team to map the coma in dust emission, which will provide information on particle size and on the gas/dust ratio, as a function of position in the coma.

  • PROJECT INVESTIGATORS:
    William Irvine
    Co-Investigator
  • RELATED OBJECTIVES:
    Objective 3.1
    Sources of prebiotic materials and catalysts