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Astronomers
David Andersen
I’m interested in the structure and dynamics of disk galaxies like our Milky Way. In particular, my research has focused on using Integral Field Units (IFUs) to study the velocity fields of relatively nearby spiral galaxies. I am a core team member of the “DiskMass Survey,” in which we combine H-alpha and stellar velocity fields, deep optical and near-infrared imaging, and Spitzer data in order to obtain independent (non-stellar population-based estimates) measures of the mass surface density of spiral disks for roughly 30 galaxies. This measurement will help break any degeneracy in rotation curve decompositions.
In addition to the DiskMass Survey, I’ve studied asymmetries and the intrinsic ellipticities of normal, unperturbed disk galaxies. I’ve also modelled the velocity fields of very late-type galaxies in an effort to find clues to their formation and composition.
These IFU studies took me into the world of astronomical instrumentation; I was co-PI of the SparsePak IFU for the WIYN telescope. Currently, I’m heavily involved in the Adaptive Optics (AO) research program at HIA. In particular, I draw upon my extragalactic background when working to design the next generation of wide-field AO systems. I am involved in NFIRAOS for TMT, GLAO for Gemini and CFHT, the University of Victoria Raven Project, and was the PI of VOLT at DAO.
Nick Ball
My research interests are in observational extragalactic astronomy, focusing on using data mining techniques to extract novel science from large wide-field survey datasets.
I was Principal Investigator of a NASA-funded project to apply machine learning algorithms to data from the Sloan Digital Sky Survey (SDSS), and NASA’s Galaxy Evolution Explorer (GALEX). We showed that the addition of the GALEX ultraviolet data substantially improves the accuracy of ‘photometric redshifts’, a measure of distance, for quasars. Quasars are the active nuclei of distant galaxies, and a tracer of the large scale structure of the universe. Also, for purely visual data, for which many further quasars are available, the use of full probability density functions in distance also significantly improved the results, by virtually eliminating the ‘catastrophic failures’ seen in previous work. Ongoing work is using these distances to investigate the clustering of active galactic nuclei within the multi-wavelength COSMOS survey.
Working with Sloan Digital Sky Survey (SDSS) data, we showed that a machine learning technique called an artificial neural network is able to classify galaxy morphologies with the same accuracy as human experts, but for far larger samples in a given time. We made the first large-scale use of these types of classifications in a study of the galaxy luminosity function in the SDSS, and also found that colour is a stronger predictor of the environment of a galaxy than morphology.
Currently, my two main projects are: (1) involvement in the Next Generation Virgo Survey, leading both the Science Working Group studying the galaxy luminosity function, and a sub-group on photometric redshifts; (2) implementing data mining algorithms for large datasets on the CADC infrastructure, which aims to build on the CADC’s CANFAR project and provide these tools to the wider astronomical community. I am also a member of the International Virtual Observatory, as part of the ‘Knowledge Discovery in Databases’ Interest Group, and am a lead author on a guide that the group is producing on data mining in astronomy. I also authored an invited review of the subject for the International Journal of Modern Physics D.
John Blakeslee
I study the properties and evolution of galaxies, clusters, and the large-scale structure of the universe using data from the Hubble Space Telescope and mountain-top observatories. I am the principal investigator for five Hubble programs, several of which are ongoing, and a co-investigator on many others.
These studies address the distances and internal structures of clusters of galaxies in the local universe, as well as the galaxy and star cluster populations within them. An important aspect of my work is the method of surface brightness fluctuations (SBF), which makes it possible to measure very accurate galaxy distances from the degree of smoothness of their light distributions. I’m also interested in the way the gravitational pull from massive nearby galaxy clusters, including their dominant dark matter components, affect the motion of our Milky Way galaxy. The ultimate goal of my work is to understand the detailed three-dimensional structure of the universe and our location within it.
David Bohlender
I have a number of research interests that utilize high-resolution and high signal-to-noise optical and infrared spectroscopy and spectropolarimetry. Many of these interests include various areas of stellar astrophysics:
- detailed studies of the three-dimensional isotopic abundances of chemically peculiar stars,
- the measurement of strong, large-scale magnetic fields in massive stars
- the interaction between these magnetic fields and the winds from such stars, and
- investigations searching for interactions between massive extra-solar planets and their host stars.
I am also involved in a research program that uses such astronomical spectra in conjunction with laboratory molecular spectroscopy to try to solve the riddle of the origin of the Diffuse Interstellar Bands, strong absorption features that originate in the interstellar medium and are superimposed on the spectra of many distant, hot stars.
I manage the scientific operation of the Dominion Astrophysical Observatory’s 1.2-m and 1.8-m telescopes and act as the project scientist for several astronomical archives developed and operated by the Canadian Astronomy Data Centre (CADC). I am also a member of the Steering Group for the CFHT Large Program Magnetism in Massive Stars (MiMeS).
Mark Booth – Visiting Worker
My research interests lie in the field of planetary systems. I work on the modeling of debris discs with specific interests in the collisional evolution of these discs, their origin and comparisons with the Solar System, allowing us to understand how common systems like our own are. I am a member of the modeling team for DEBRIS: an unbiased survey of debris discs using the Herschel Space Observatory.
Carlos Correia Da Silva
Pat Côté
Stéphanie Côté
Dennis Crabtree
David Crampton
My scientific research interests in recent years are mostly focused on understanding the formation and evolution of high redshift galaxies, especially making use of gravitational lenses. These lenses amplify and magnify the light of background sources and so greatly aid in the study of very small, faint sources.
On the technical side, I have been involved in the development of astronomical instruments, and adaptive optic systems, mostly for ground-based telescopes such as CFHT and Gemini. I have also played a major role in leading the instrumentation program for TMT and am currently a member of the ESO Scientific Technical Committee.
Tim Davidge
My primary research interest is galaxy evolution. I investigate galaxy evolution by studying the spatial distribution of stars in nearby galaxies that have well established properties, and hence can be used as archaeological tracers. I also investigate the integrated spectrum of more distant galaxies, using stellar absorption lines as tracers of stellar content.
I am on the TMT Science Advisory Committee, as well as the science team for IRIS, which is a first-light TMT instrument.
James Di Francesco
Sean Dougherty
Daniel Durand
Greg Fahlman
Cassandra Fallscheer – Visiting Worker
During my PhD studies at MPIA in Heidelberg Germany, I looked into the role of accretion disks in massive star formation using millimeter line and continuum data from both single dish telescopes and interferometers. I studied three regions at different evolutionary stages of the massive star formation process looking for supporting evidence for an accretion-based formation scenario of massive stars.
At HIA, joined the Herschel imaging survey of OB Young Stellar objects (HOBYS) and Gould Belt Survey Herschel key program projects. HOBYS will survey all close regions (within 3 kpc) of massive star formation with both the PACS and SPIRE instruments. The purpose of the project is to gain a better understanding of how O and B stars form. The Gould Belt survey will focus on the earliest stages of star formation specifically with the aim of better understanding the origin of the stellar initial mass function.
Laura Ferrarese
My research interests focus on:
- the study of supermassive black holes and the connection they share with their host galaxy;
- the structural and kinematical properties of galaxies, from their nuclei to their extended stellar haloes;
- the extragalactic distance scale and the expansion rate of the universe.
I use data from both ground- and space-based observatories, such as the Hubble Space Telescope (HST), the Chandra X-ray Observatory and the Canada-France-Hawaii Telescope (CFHT).
I was part of the HST Key Project for the Extragalactic Distance Scale, which measured the Hubble constant with unprecedented 10% accuracy, and the HST Advanced Camera for Survey Virgo and Fornax Cluster Surveys, to date the most comprehensive surveys of early type galaxies in the local Universe. I am the Principal Investigator of the Next Generation Virgo Cluster Survey (NGVS), an international collaboration which is exploiting the 340 Megapixel MegaCam instrument on CFHT to study the Virgo Cluster, the largest collection of galaxies within 35 megaparsec.
Wes Fraser - Plaskett Fellow
Vic Gaizauskas – Volunteer Visitor
My research aims to establish links between the evolution of solar active regions and the formation of chromospheric filaments (cloud- like prominences that are seen against the Sun’s disc as thin, highly elongated, dark structures). These dense clouds of cool chromospheric matter are supported for very long times (many hours to months) by magnetic fields at coronal heights where the ambient temperatures outside the filaments are greater by a factor of 100. I provide theorists with observations of the initial velocity and magnetic fields surrounding a filament-forming ambience in order to constrain their choice of physical models for these intriguing objects.
My observations consist of large-scale monochromatic images (in the hydrogen alpha line) of single active regions that were filmed by means of time-lapse photography at the Ottawa River Solar Observatory during Solar Cycle 21 and part of Cycle 22 (1976–92). I search this large film archive for examples of filaments whose evolution can be followed for many days, including the early stages of formation.
My international collaborators are associated with PROM (Prominence Research Observations and Models), an informal group of solar researchers whose interaction at annual workshops is made possible with travel funds provided by NSF to Helio Research Corporation, La Crescenta, California.
Joern Geisbuesch
Andrew Gray
Elizabeth Griffin – Volunteer Visitor
I am deriving stellar masses by analysing high-dispersion stellar spectra observed with DAO’s 1.2-m telescope. The program targets binary stars having composite spectra (they consists of a cool giant and a hotter dwarf, and the spectra of both are visible at the observed wavelengths), and a subtraction technique has been developed for separating the two spectra so that their relative velocities can be measured accurately
I also Chair the IAU Task Force on the Preservation and Digitization of Photographic Plates, and am energizing the HIA’s own efforts to digitize its substantial heritage of over 100,000 historic stellar spectra. To demonstrate the potential of securing digital information from such data I analyzed a number of historic spectra in order to determine the concentration of the Earth’s ozone at an epoch when ground-based ozone measurements were scarcely started.
Stephen Gwyn
Jim Hesser
Throughout my career, my research interests have spanned a wide variety of topics from laboratory astrophysics to variable stars (particularly ZZ Ceti stars) to stellar populations of the Milky Way and nearby galaxies, with an emphasis on clusters of stars ranging from young to ancient. Most of my research has been done with optical/infrared telescopes on the ground or in space.
In recent years, however, my focus has been on two quite different activities. First, supporting Canada’s role in the development and international governance of ALMA, the Atacama Large Millimeter Array, the world’s first global astronomy observatory being developed by East Asia, Europe and North America to study the cold universe of star and galaxy formation; and, second, education and public outreach stimulated by the International Year of Astronomy 2009 and Beyond IYA efforts to use the appeal of astronomy to increase public understanding of science generally and to encourage young people to consider careers in science and technology.
John Hutchings
My research interests include all forms of active galactic nuclei and their host galaxies, as well as the study of galaxy evolution in the early universe. I also have a long-standing interest in massive young stars, X-ray binaries, and the interstellar medium. My observational work uses facilities covering most of the range from radio to X-ray wavelengths.
I am the Canadian project scientist for the James Webb Space Telescope, and also the ISRO Astrosat observatory. These activities include instrument development and calibration, and also science planning for these facilities.
Doug Johnstone
My research interests lie in how stars are formed, from the assembly of molecular cloud material through the collapse of these clouds to individual stellar systems. I am also interested in the evolution of disk of material around young stars. I am a science team member on many space (Spitzer Space Telescope, Herschel Space Observatory, and the (to be launched) James Webb Space Telescope) and ground-based (JCMT, IRAM, and Gemini) projects. I am also Canada’s representative on the ALMA Science Advisory Committee.
I currently have three graduate students working with me: Matt Penrice (Master’s at U. Vic), Aaron Maxwell (Master’s at U. Vic), and Andy Pon (PhD at U. Vic).
JJ Kavelaars
My research activities focus on measuring the orbital characteristics of the minor bodies (e.g., asteroids) of the solar system, with particular focus on the Kuiper belt. The physical and orbital properties of these objects provide interesting information about the long-term evolution of planetary systems and are particularly sensitive to the orbital histories of the giant planets. I am also participating in surveys of debris disks around nearby stars. This work is providing constraints on the timescales and conditions of planet formation.
In addition to my research projects I also serve as the Canada-France-Hawaii Telescope (CFHT) Archive Scientist within the Canadian Astronomy Data. The CADC houses the largest (by data volume) collection of astronomical data in the world, serving thousands of astronomers annually by providing archival access to raw science images from various astronomical telescopes and by producing catalogues of astronomical sources detected in those images. The CADC is a leader in the Virtual Observatory.
Roland Kothes
Tom Landecker
Lauren MacArthur
Rita Mann – Plaskett Fellow
My research interests are focused on understanding the planet formation process. I study protoplanetary disks around young stars to determine if they contain enough mass to potentially form planets like those in our Solar System. My research focuses on regions like the Orion and Rosette Nebula, which are known to be similar to the birth environment of our Sun. I use arrays of telescopes, or interferometers, operating at submillimetre-to-radio wavelengths, including the SMA, eVLA, CARMA and ALMA.
Christian Marois
Brenda Matthews
My research interests lie in the origins of stars and planets, particularly in the study of molecular clouds and the smaller dense cold cores within these clouds that form stars. This also includes the disks which surround forming stars and are the location of planet formation.
In addition, I study debris disks around stars, the analogues of the Kuiper belt around our Sun. These debris disks reveal the diversity of Solar Systems by revealing the diverse geometries of planetestimal systems.
I am the Principal Investigator of the DEBRIS (Disc Emission via a Bias-free Reconnaissance in the Infrared/Submillimetre) Key Project on the Herschel Space Observatory, the Canadian Coordinator of the SCUBA-2 Unbiased Nearby Stars Survey (SUNSS), the polarization science team leader for the SCUBA-2 Gould Belt Survey and a member of the Spitzer Gould Belt Survey.
Alan McConnachie
My current research is aimed at understanding the history of the Universe and “galactic archaeology”. I use the detailed properties of individual stars and collections of stars in nearby galaxies as probes of their formation, evolution, dynamics and dark matter content. This research is at the interface of many fields of astronomy, including cosmology, galaxy dynamics, stellar populations and stellar evolution. Among other science projects in which I am involved, I am Principal Investigator of the Pan-Andromeda Archaeological Survey (PAndAS), an international collaboration that is studying our nearest large galactic neighbors in unprecedented detail.
Donald Morton – Researcher Emeritus
I am presently performing calculations of transition probabilities in atomic systems from first principles — specifically the relativistic corrections for the helium atom using the Breit-Pauli approximation to the Dirac equation.
Russell Redman
Tim Robishaw - Covington Fellow
David Schade
Gerald Schieven
Luc Simard
Eric Steinbring
Peter Stetson
Ken Tapping
Jacques P. Vallée – Volunteer Visitor
My research focuses on magnetic fields in the Universe. This includes magnetic fields in space, in galaxy clusters, in gas and dust clouds, in gaseous wisps, in dark interstellar globules, in forming protostars, in the interplanetary medium and on the solar surface. My current research is aimed at observing magnetic fields with the telescopes in Hawaii to study interstellar clouds from which future stars and planets (the Yellow Road of Life) will form.
Sidney van den Bergh – Researcher Emeritus
My recent research has been concentrated in two areas:
- The classification, evolution and morphology of galaxies.
- The origin, properties and evolution of nearby systems of globular clusters.
Tony Willis
My general research interests include the processing of radio astronomy images, the design and configuration of arrays of radio telescopes, and extragalactic radio astronomy.
Currently I’m mostly interested in studying imaging capabilities of the next-generation of radio telescopes. One can take the output of antenna design software and simulate an observation made with a radio telescope that uses such antennas. These simulations are done with the MeqTrees software package, a package that I collaborate on together with a group at ASTRON, a organization similar to HIA in the Netherlands. The quality of the images produced with such a computer-generated telescope can then be evaluated and the user can decide if the proposed telescope design meets the requirements of astronomers for image fidelity and stability.
Chris Willott
I am interested in the evolution of galaxies and their central black holes from very early in the history of the Universe up until today. I currently conduct research on black hole demographics; the interplay between black holes and their host galaxies and the intergalactic medium; the physics of emission at many wavelengths from active black holes; dust, gas and star formation in distant galaxies. I use observations from telescopes across the electromagnetic spectrum such as the EVLA, IRAM, JCMT, Spitzer, Gemini, CFHT, Keck, HST and Chandra.
- I am the Principal Investigator of the Canada-France High-z Quasar Survey which has discovered many of the most distant quasars known, observing them as they were within the first billion years of the Universe.
- I am co-PI of a CFHT Large Program started in August 2010 to push this search for quasars up to redshift 7 and co-PI of the completed CFHT Large Program, the WIRCam Deep Survey, which observed the CFHTLS-Deep fields in the near-infrared to probe galaxy and cluster evolution.
Graduate Students
Kaushala Bandara (Victoria - PhD) – Supervisor: Crampton
My current research interests are focused towards resolving the photometric and kinematic properties of distant galaxies by utilizing strong gravitational lensing. One component of my thesis project involves combining deep Hubble Space Telescope (HST) imaging, in optical and infrared bands, of gravitationally lensed high-redshift galaxies to extend the study of scaling relations between galaxy size, luminosity and stellar mass below the low-mass end of existing surveys. This analysis provides observational evidence to test galaxy formation models, especially disk galaxy evolution at the low-mass end. The other component of my thesis project involves obtaining detailed two-dimensional dynamical information and star formation rates for a representative sample of high redshift galaxies, by taking advantage of the increased spatial resolution and flux provided by gravitational lensing.
Shadi Chitsazzadeh (Victoria – PhD) – Supervisor: Di Francesco
I study the earliest stages of the star formation process. Stars play a crucial role in the origin and the physical and chemical evolution of various astronomical environments such as galaxies, the interstellar medium, and planets, which makes understanding their formation one of the most important goals of astronomy. Their formation involves a sequence of different stages that starts with the fragmentation of a molecular cloud into dense, gravitationally bound cores. It continues with the collapse and evolution of these condensations into protostars as a result of a combination of mechanisms that are still poorly understood. The observational characterization of cores that are on the cusp of gravitational collapse has a pivotal role in our understanding of the initial conditions of star formation. High-frequency radio emission from molecular gas that exist in star forming regions provide the means to observe the process. I will use single dish telescopes like the GBT and NRO as well as interferometers such as EVLA, and ALMA to gather data
Lisa Glass (Victoria - PhD) – Supervisor: Ferrarese
I am a PhD student based at the University of Victoria as well as at HIA working with Laura Ferrarese. I study the central regions of relatively nearby elliptical and lenticular galaxies in the Virgo and Fornax clusters, which are around 50 million light years away. Astronomers have known for a while that all big galaxies have enormous black holes at their centres, weighing millions to billions of times more than our sun. More recently, we’ve discovered that most medium and small galaxies have huge, bright star clusters at their centers. My research focuses on how these star clusters form and evolve as well as how they might be related to the supermassive black holes we see in larger galaxies
Ben Hendricks (Victoria – PhD) – Supervisor: Stetson
I am working with Peter Stetson and Don VandenBerg on Horizontal Branch morphologies of Galactic Globular Clusters (GGC) and on near-infrared Color-Temperature (CT)-Relations.
For my research, I am using own images as well as 2MASS archival data to combine near-infrared with optical broad-band photometric data of GGCs and compare the results with theoretical models. Near- infrared photometry is interesting for the observation of element abundances in GGCs and accumulation of interstellar dust. CT-Relations are the key to link observational data with theoretical models and can be used to obtain constraints on basic parameters such as the age of our own galaxy or the distance from far away systems.
Andy Pon (Victoria – PhD) – Supervisor: Johnstone
I study large-scale process in star forming regions. Giant molecular clouds (GMCs), in which stars form, are known to contain supersonic, turbulent motions and I am currently attempting to determine how this turbulence dissipates. I am also looking into how quickly small segments of a GMC will collapse, relative to the entire cloud collapsing, depending on whether the GMC is spherical, disk-like or filamentary. Finally, I am also studying the properties of the Orion-Eridanus superbubble.
Sarah Sadavoy (Victoria - PhD) – Supervisor: Di Francesco
My research focuses on star formation. In particular, I’m interested in how material in large clouds condenses into smaller structures (cores) and how these small structures evolve into stars. Currently, I am involved in the three international survey groups. First, the SCUBA-2 Gould Belt Survey aims to observe very cold dust in nearby dense star forming clouds. Second, the Herschel Gould Belt Survey, will observe many star forming clouds over a range of wavelengths to determine their physical properties (i.e., temperatures). Third, the Herschel OB Young Stars survey explores how very large, massive stars form in contrast to low-mass star formation.
Monica Turner (Victoria – MSc) – Supervisor: Pat Côté
I am working on the ACS Fornax Cluster Survey with Pat Côté. I am looking at elliptical and lenticular galaxies in the Fornax Cluster, which is one of the most populated nearby galaxy clusters. Many of the smaller galaxies in this survey were found to have compact star clusters at their centres. The focus of my research is examining the properties of these stellar nuclei, and their connection to supermassive black holes.
