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Faculty of Science

Department of Physics & Astronomy

Ralph Pudritz
Ralph Pudritz

Contact Info

Ralph
Pudritz
Professor
ABB 318
23180
905-546-1252
...

Summary

I am a theoretical astrophysicist and my research focuses on star and planet formation. I completed my undergraduate studies at UBC in mathematics and physics. I then moved to the University of Toronto for my M. Sc. (in theoretical physics). I returned to UBC to do my Ph.D. in astrophysics under the supervision of Greg Fahlman, completing it in 1980. I took up an NSERC Postdoctoral Fellowship at the Institute of Astronomy in Cambridge (England). I went on to further postdoctoral research with Chris McKee and Jon Arons at the Astronomy Dept. at Berkeley, and with Colin Norman at the Johns Hopkins University. I joined the faculty at McMaster in 1986. Research Leaves and Fellowships over the subsequent years have taken me to many outstanding research centres including the Observatoire de Grenoble (1988, 1992), the Max-Planck Inst. for Astronomy in Heidelberg (1993), the Harvard-Smithsonian Center for Astrophysics (1993), the Max-Planck Institute for Astrophysics in Munich (1997), the Canadian Institute for Theoretical Astrophysics (CITA) in Toronto (1990 and 1997), Caltech (2001), and the Kavli Institute for Theoretical Physics (KITP) in Santa Barbara (2007/08).

I have been involved in many aspects of Canadian as well as international astronomy and astrophysics, having served on Time Allocation Committees (CFHT and JCMT), NRC Science Advisory Committees (Gemini, JWST), Visiting Committees (U.S. NRAO), Advisory Boards (HIA, CITA Council), and review committees. I chaired Canada's decadal survey of Astronomy and Astrophysics - the NRC-NSERC Long Range Planning Panel (1998/2000) - and was the principal author of the LRP report; "The Origins of Structure in the Universe". The LRP is playing the central role in guiding the development of Canadian astronomy in this decade and beyond, having involved Canada in ALMA, JWST, TMT, SKA, and several other important space and ground based telescopes and observatories.

Most recently, I spear-headed and am the founding (2004) Director of McMaster's Origins Institute (OI). Its scientific mission is to engage in fundamental transdisciplinary research on the origin of structure and life in the cosmos. The scientific themes of the OI cover 6 broad themes in science: the origin of space and time (cosmology, early universe), structure in the universe (planets, stars and galaxies), the elements, life (astrobiology), species and biodiversity, and humanity. In addition to its research foci, the OI has developed a novel OI Undergraduate Research specialization. The OI is committed to public outreach and education through its award winning OI Public Lecture series and played an important role in the creation of the McMaster 3D theatre. The OI has also run major international annual scientific conferences on some of the most important questions in contemporary science.

Star formation, planet formation, astrobiology

Courses

Department of Physics and Astronomy

I have taught a wide variety of undergraduate as well as graduate courses, in both astrophysics and physics. I have often taught graduate courses on Star Formation (Physics 778), the Interstellar Medium (Physics 785) and Galactic Dynamics (Physics 781). In the undergraduate program, I have often taught the Introductory Astronomy and Astrophysics course (Astron 1F03), first year physics, and upper level courses such Galaxies and Cosmology (Astron 3X03), and Stellar Structure (Astron 3Y03).

Origins Institute

I have worked extensively with my OI collaborators, Jonathon Stone and Alison Sills, to create and realize a new concept for teaching transdisciplinary courses in fundamental science. We designed the Origins Undergraduate Research Specialization to take students into the heart of 6 of the most fundamental streams of research in 21st century science. These subjects transcend the traditional subjects in science calendars, since these fields are often highly transdisciplinary. Our philosophy is to insure that students that are deeply trained in a particular field (hence requirement to be registered in a traditional Honours Science Program), are at the same time sufficiently immersed in the broad set of fundamental science themes that are emphasized in the OI programs.

This approach is accomplished by first having our students go through a set of survey courses in their first year of the program (e.g. Big Questions). Their interests are then sharpened in the second year of the program through a selection of courses centred on each of the 6 basic themes. All the while, we expose students to the fundamental literature and new scientific results in these fields by means of highly interactive seminars (Origins 2S03 and 3S03). The first of these is designed to take the students through the basic literature, guided by OI faculty. The 2nd year seminar exposes students to visiting scientists and their colloquia as part of the OI colloquium series. The capstone of the program is the OI undergraduate thesis, taken in the 3rd and final year of the program. Here the student is encouraged to work in any area that they have taken an interest in, and to seek appropriate OI supervisors. Our OI students are invited to meet with OI Public Lecturers to broaden their exposure to outstanding scientists at a very early stage in their careers.

I have personally developed and taught, in collaboration with Paul Higgs, the Origins of Life (Astrobiology - Origins 3D03) course. The OI is building a strong research presence in this field, and students participate in this very exciting, emergent new science.

Letter to Grad Students

Ralph Pudritz
Department of Physics & Astronomy
McMaster University

Dear Prospective Graduate Student,

My research focuses on the theoretical and numerical study of star and planet formation, and recently on how biomolecules such as amino acids form in astrophysical environments. Star formation plays a central role in astrophysics because it impacts a wide range of processes - from planet formation in protostellar disks, to galaxy formation and evolution, and even cosmology. The discovery of more than 200 extrasolar planets, some with as little as five Earth masses, has revolutionized our thinking about how planetary systems form and evolve. The advent of new observatories such as the James Webb Space Telescope, as well as the Atacama Large Millimeter Array (ALMA) will allow us to study these processes with unprecedented resolution. There could not be a better time to be working on these fundamental questions.

My research in star formation explores a wide range of interconnected problems. My ultimate goal is to develop a seamless picture of star formation, starting from the scale of the galaxy, down to the scales at which molecular clouds are formed, to the formation of star clusters within these clouds, to the collapse of individual gas “cores” within such clustered environments (to form single or binary stars), and on down to the scales that characterize the physics of protostellar disks through which gas accretes onto their central stars and from which highly collimated jets are launched. Together with my students, postdocs, and collaborators, we have pioneered the study of jets from protostellar disks that are observed around all young stars. We have also shown that outflows arise as an intrinsic part of gravitational collapse of molecular cloud cores. On larger scales, we have simulated the earliest stages of the formation of star clusters within the densest clumps of dusty, magnetized gas within molecular clouds. Students in my group use state of the art, Adaptive Mesh Refinement codes to follow this process from parsec to stellar spatial scales. This research is also the first step towards understanding how star clusters and the well known mass distribution of stars (the so-called “initial mass function”) arise. An important application of this work on cluster formation is towards an understanding of how the earliest stars and globular clusters formed at high red shifts. My group has also gone deeply into the astrophysics of the disks out of which stars and planets arise.

Our planetary studies have investigated how planetary systems form and migrate within their natal disks. It is believed that the “hot Jupiters” that are found in extrasolar systems were not formed close to their central star, but rather migrated from larger distances out in their disks. My students and I have worked on new theories and models for how planets migrate in gas disks, and on what might prevent them from “splashing” into their central stars. Currently, I am interested in extending this research to the question of how terrestrial planets form and am currently just starting new work with students on this question.

Through my involvement in the Origins Institute, I have now started to work (together with some graduate students) on trying to understand the origin and evolution of biomolecules. The presence of amino acids within meteorites shows that such biomolecules were probably made within protostellar disks, and survived their delivery to the Earth. We are examining the astrochemistry of such molecule formation, with the intent of understanding how pre-biotic conditions arose on terrestrial planets. This is a significant step towards understanding the origins of life on Earth, and possibly in other planetary systems.

I currently have four graduate students and a postdoc working in my group. My students work on both theoretical and numerical aspects of these problems. I try to ensure that my students work on linked problems. Through group meetings, we stay in close contact with one another so that students don’t work in isolation but are all part of a larger picture. Research is open-ended, and I believe in having students work on problems that are at the cutting edge in any given field. The exact problem that a student works on is a mix of their interests and mine. By the end of their work in my group, my students are working as independent researchers and are leaders in their field. My students have done very well in their careers - with three of my six completed Ph.D. students working as faculty members in universities, two currently working as postdocs, and one working in a research position in climate modeling. I have had a number of outstanding postdoctoral research fellows working in my group, and this has been excellent for my students as well.

I have many interesting research projects within this broad set of themes. I will be happy to discuss these with you. If you are interested, please send me e-mail at pudritz@physics.mcmaster.caor consult my departmental home page. I look forward to hearing from you!

With best wishes,
Ralph Pudritz

McMaster University - Faculty of Science

Mailing Address

Department of Physics & Astronomy,
McMaster University

ABB-241
1280 Main Street West
Hamilton, Ontario, Canada
L8S 4M1

Contact Information

Telephone Inquiries:
+1 (905) 525-9140 ext.24559
Fax:
(905) 546-1252
Email Inquiries:
physics@mcmaster.ca

McMaster University - Faculty of Science

Mailing Address

Department of Physics & Astronomy,
McMaster University

ABB-241
1280 Main Street West
Hamilton, Ontario, Canada
L8S 4M1

Contact Information

Telephone Inquiries:
+1 (905) 525-9140 ext.24558
Fax:
(905) 546-1252
Email Inquiries:
physics@mcmaster.ca