A Letter of Intent to Submit a Proposal to the
NSERC Collaborative Research Opportunities Program


A.R. Taylor                  Physics and Astronomy, University of Calgary
Shantanu Basu              Physics and Astronomy, University of Western Ontario
Claude Carignan           Physics, Université de Montréal
Jayanne English             Physics and Astronomy, University of Manitoba

Nadia Ghazzali             Mathematics and Statistics, Université Laval
Judith Irwin                   Physics, Queen's University
Doug Johnstone            Astronomy, University of Toronto
Gilles Joncas                 Physics, Université Laval
Denis Leahy                 Physics and Astronomy, University of Calgary

George Mitchell            Astronomy and Physics, St. Mary's University
Peter Martin                 Canadian Institute for Theoretical Astrophysics
Bill McCutcheon           Physics and Astronomy, University of British Columbia
Serge Pineault               Physics, Université Laval
David Routledge           Electrical and Computer Engineering, University of Alberta
Nicole St-Louis            Physics, Université de Montréal

Peter Dewdney             Herzberg Institute of Astrophysics, National Research Council
Daniel Durand              Herzberg Institute of Astrophysics, National Research Council
Andrew Gray               Herzberg Institute of Astrophysics, National Research Council
Lloyd Higgs                  Herzberg Institute of Astrophysics, National Research Council
Lewis Knee                  Herzberg Institute of Astrophysics, National Research Council
Tom Landecker            Herzberg Institute of Astrophysics, National Research Council
Ken Tapping                Herzberg Institute of Astrophysics, National Research Council
Tony Willis                   Herzberg Institute of Astrophysics, National Research Council

Roy Booth                    Onsala Space Observatory, Sweden
John Dickey                 University of Minnesota, USA
Ernst Furst                    Max-Planck-Institut fur Radioastronomie, Germany
Anne Green                  University of Sydney, Australia
Mark Heyer                 Five Colleges Radio Astronomy Observatory, USA
Jim Jackson                  Boston University, USA
Lars Johansson             Onsala Space Observatory, Sweden
Jay Lockman                National Radio Astronomy Observatory, USA
Patricia Reich               Max-Planck-Institut fur Radioastronomie, Germany
Wolfgang Reich            Max-Planck-Institut fur Radioastronomie, Germany
Richard Wielebinski      Max-Planck-Institut fur Radioastronomie, Germany


Background: The Canadian Galactic Plane Survey

Since its inception in 1995, the Canadian Galactic Plane Survey (CGPS) has been a scientific, technical, and educational success, and has garnered wide support from Canadian astronomers. It is a pioneering effort to study the complex processes that shape the interstellar medium (ISM) of our Galaxy and influence Galactic structure and evolution. Significant progress in this endeavour can only be made with the use of complementary data sets which trace all of the major constituents of the ISM, and thus the major observational task of the CGPS Consortium has been to produce high angular resolution (~1') images of these components over a 630 square degree section of the northern Galactic Plane. The most important of these data sets are atomic hydrogen (HI 21 cm line spectroscopy with the DRAO Synthesis Telescope national facility), molecular hydrogen (as traced by CO in the FCRAO Outer Galaxy Survey, OGS), thermal and non-thermal ionized gas (DRAO 21-cm and 74-cm continuum images), the magneto-ionic medium (DRAO 21-cm continuum polarization), and dust (IRAS data). All of the CGPS data provided by DRAO has come from a dedicated survey carried out by the observation and data processing teams at the University of Calgary and at HIA, and the CO and IRAS data are enhanced versions reprocessed by the Consortium for the CGPS.

The CGPS Consortium has a membership of 60, 45 of whom are astronomers or graduate students at Canadian universities and institutes. With support from the NRC and NSERC, the CGPS has made major new discoveries in the ISM of our Galaxy, has contributed to the training of astronomy and engineering students in Canada (many of whom have gone on to fill positions in Canadian Universities), and provides a successful model of a large astronomical collaborative research program. The Report of the NRC-NSERC Long Range Planning Panel describes the CGPS as “an exemplary project for its scientific impact upon our knowledge of the galactic interstellar medium, the extensive collaborative links between NRC and universities that it has fostered, and the training of a new generation radio astronomers in this country”.  The LRP includes among its major recommendations an extension of the CGPS project for 2001-2005. In this Letter of Intent, we propose the extension of the CGPS to a second phase as part of a wider and yet more ambitious international collaborative program.


The Collaborative Opportunity: The International Galactic Plane Survey

The success of the CGPS has spurred an independent, similar, but smaller scale survey of Southern Galactic Plane Survey (SGPS) with the ATNF. This opened up the possibility of an International Galactic Plane Survey (IGPS), and the CGPS Consortium has been leading the effort to put together this international collaboration.

The first element of the IGPS is a collaborative program to image the HI line at ~ 1' resolution over nearly the entire Galactic Plane. There are three observational components to this element of the IGPS: (1) the extension to completion of mapping of that part of the northern Plane which is well placed for observation at DRAO, (2) the SGPS, and (3) a survey (the VGPS) with the VLA which covers that part of the Plane inaccessible to both DRAO and the ATNF. Together, the extended CGPS, the VGPS, and the SGPS will encompass 287 degrees of longitude of the Galactic Plane, amounting to over 90% of the area of the stellar disk of the Galaxy. Our proposal for observing time to begin the VGPS (principal investigator: A.R. Taylor) has already undergone special, rigorous peer review by NRAO, and is now a major VLA program, with an initial installment of 260 hours in the upcoming D-array session. The SGPS is continuing, and observations at DRAO for the extended CGPS already begun.

The second element of the IGPS is to provide complementary spectroscopic images of molecular line emission over a large portion of the IGPS HI survey area.  Again, there are three observational components: (1) the FCRAO OGS (already in hand from the original CGPS), (2) the ongoing Boston University-FCRAO survey of the Inner Galaxy molecular ring, and (3) a new large-scale survey at Onsala Space Observatory linking the OGS and BU-FCRAO surveys. Our proposal to Onsala for the latter has also been peer-reviewed and 500 hours of observing time initially allocated.

The third element is a collaboration with the Max-Planck-Institut fur Radioastronomie to provide 21 cm polarimetric data from the Effelsberg 100 metre radio telescope. The data on the large angular scale polarization from the 100 metre telescope, when combined with the small angular scale data from DRAO, will be crucial for the proper interpretation of the properties of the Galactic magneto-ionic medium. The fourth element will be the incorporation of HIRES reprocessed IRAS data in all four bands to yield ~ 1' resolution dust maps of the entire area covered by the extended CGPS/IGPS.


Disk-Halo and Low Mass Clouds: A High Latitude Survey

Some of the most exciting discoveries from the CGPS have been those related to mass and energy transfer between the Galactic disk and the halo outflow, e.g. the Galactic Chimney (Normandeau et al. Nature, 1996) and the Galactic Worm (English et al. ApJ Letters, 2000). Such features have never before been seen in our Galaxy or in any other galaxy. These types of phenomena reveal disk-halo gas dynamics crucial to our understanding of the enrichment of the global evolution of the Galaxy, its chemical and star formation history, and its connection to the inter-galactic medium.

Both the Chimney and Worm structures required follow-up observations at latitudes outside the original 9-degree band of the CGPS: observations of low resolution Galactic HI and of external galaxies confirm that while the CGPS latitude band is usually sufficient to fully map structures in the thin HI and molecular disks of the Galaxy, it is insufficient to fully characterize disk-halo phenomena. Therefore the extended CGPS includes a high latitude extension up to +18 degrees over a selected longitude range in the outer Galaxy. This survey of a section covering the Perseus and Outer Arms to high z-heights (~ 1 kpc in the case of the Perseus Arm), will be the first high resolution HI/continuum disk-halo survey, and will also be probed in polarization in collaboration with the MPIfR group.

Our choice of the longitude/latitude range of the disk-halo extension also will permit us to observe the nearby (300 pc) extended Cepheus Flare Molecular Clouds Complex, a region of active low- to intermediate-mass star formation. This will be the first survey of neutral atomic gas associated with a low mass star formation region covering size scales ranging from the complex as a whole (100 pc) down to the scale of individual star forming cores (~0.1 pc). Detailed studies of the distribution and kinematics of molecular and HI gas over a wide range of scales will help to understand the relationship between the molecular and atomic constituents of clouds and to understand the disruptive phenomenon of star formation, e.g. parsec-scale molecular outflows and their impact on cloud HI halos upon their break out from the molecular cores.

Summary

The extended CGPS/IGPS will continue the revolution in the study of the ISM of our Galaxy begun by the original CGPS (see "New Perspectives on the Interstellar Medium", ASP Conf. Series 168). The mapping and analysis of the HI and CO spectra and dust and radio continuum images will lead to a description of the spatial, dynamical, and thermal structure of the ISM and the relationship between the phases over the entire disk of the Galaxy. The full data set arising from this collaboration will be unprecedented in its sensitivity, resolution, and completeness across wavebands, and will set the standard for such surveys in the future. It will provide a unique resource for the astronomical community, with each mosaic being released to the Canadian Astronomy Data Centre, as soon as processed.  The derived 3-D image of the Galaxy is sure to be referred to in textbooks for many years to come.

The Collaboration

The co-applicants listed on the first page comprise NSERC grant-eligible Canadian university staff and NRC scientists, as well as international collaborators who are directly involved in contributing major new data sets to the international project. The collaboration also includes the current members of the CGPS Consortium, including many postdoctoral researchers, research associates, graduate students, and international colleagues who are not listed as co-applicants.

Amount Requested and Allocation of Funds

Funds will be requested under the Collaborative Research Opportunities grant program to fund the Canadian elements of the international project. Most of the funding request is for personnel to carry out data processing and scientific analysis. Funds will be allocated as follows.

$160K Four research associates with half time devoted to data processing and half to scientific analysis. Two will be stationed at DRAO to work on CGPS data. Two will be at the University of Calgary: one for the extended CGPS and one for the VGPS.

$68K Half salary for four CGPS postdoctoral fellows to be supervised by co-applicants at Canadian Universities. The remaining half of the salaries will be obtained from individual NSERC grants or departmental contributions

$10K Meeting expenses and travel for the RAs and PDFs to annual CGPS science meetings.

$12K 64-bit computer PC workstation for visualisation and analysis of the combined data sets.

Total request = $250K per annum.

Why the CRO Program?

The CRO program was selected because of the close match to the goals of this project. The IGPS takes advantage of a timely international opportunity to combine resources from several countries (Canada, Australia, Germany, Sweden, USA) to produce a high resolution, multi component image of the Galactic disk. The extended CGPS/IGPS as a whole relies upon the current availability of the DRAO Synthesis Telescope national facility, which will devote over 90% of its time to this project during the next five years. Finally, the project brings together a large international group of prominent scientists with a broad range of expertise to focus on the problem of understanding the processes that drive the evolution of spiral galaxies. Another program, which provides a close match to his project, is the partnership program with Government agencies. However, our project is a basic research program with no direct industrial involvement: the latter being a requirement of the partnership programs.

Suggested Referees

Ron Ekers                    Australia Telescope National Facility                 international perspective

Rick Perley                   National Radio Astronomy Observatory            radio astronomy techniques

Ralph Pudrtiz                McMaster University                                        ISM and star formation

Ron Reynolds              University of Wisconsin                                     Galactic ISM and surveys

Ernie Seaquist               University of Toronto                                        Canadian radio astronomy