Fall/Winter 2021
Tues September 28th, 11am, Zoom: Ting Li (U. of Toronto) Recording
The Southern Stellar Stream Spectroscopic Survey: Overview and Latest Science Results: The Southern Stellar Stream Spectroscopic Survey (S5) is an ongoing spectroscopic program that maps the newly discovered stellar streams with the fiber-fed AAOmega spectrograph on the Anglo-Australian Telescope (AAT). S5 is the first systematic program pursuing a complete census of known streams in the Southern Hemisphere, providing a uniquely powerful sample for understanding the building blocks of the Milky Way’s stellar halo, the progenitors and formation of stellar streams, the mass and shape of the Milky Way’s halo, and ultimately the nature of dark matter. The survey started in Summer 2018 and has mapped ~20 streams with over 50 nights on AAT. In this talk, I will give a brief overview of the current status of the program, highlighting the latest science results from the survey, and end the talk with the first public data release of S5. The science results from S5 cover a wide range, including the finding of a stream perturbed by the dark matter subhalos, the confirmation of a globular cluster stream that is more metal-poor than any known Milky Way globular clusters, the constraints on the mass of the Large Magellanic Cloud with stellar streams, and the discovery of the fastest hyper velocity stars ejected from Galactic center, etc.
Tues October 5th, 11am, Zoom: Allison Kirkpatrick (U. of Kansas) Recording
The Mysterious Growth of Cold Quasars: All galaxies host a supermassive black hole at their centers, at least a million times the mass of the Sun. Material falling onto these monsters can be as bright as the galaxy itself, or it may be lurking unseen behind thick blankets of dust. These monsters go through growth spurts and feeding frenzies that can greatly impact their host galaxies, possibly even terminating all nearby star formation. I will focus on Cold Quasars, which are some of the most luminous accreting black holes in the universe, and yet, surprisingly, their host galaxies have star formation rates of 1000 Msun/yr, casting doubt on whether black hole feedback impacts star formation at all. I will discuss how Cold Quasars are an anomaly in the current understanding of quasar formation.
Tues October 12th, 11am, Zoom: Andrew Mann (Chapel Hill) Recording
Planetary Systems through Time: Planets are not born in their final state. Before reaching a more mature and stable phase, young planets are sculpted by interactions with their host star, other planets in the system, and their greater environment. Large populations of mature (>1 Gyr) exoplanets, like those from the Kepler mission, provide useful but indirect constraints on the relative importance of such evolutionary processes. Because the first few hundred million years of a planet’s life are the most formative, studies of young (<<1 Gyr) planets yield more direct information of exoplanet evolution as they offer the chance to observe such processes in action. However, young planets are also some of the most difficult to identify and characterize. K2 and TESS combined with new search methods have changed the situation by enabling the discovery of transiting planets in 10 — 700 Myr clusters, moving groups, and star-forming regions. The statistical properties of these systems demonstrate that young planets are larger than their older counterparts and provide insight into the timescales of planetary migration. With the extended TESS mission, we can build on this by identifying young planets around bright stars that are amenable to studies of their atmospheres with JWST.
Tues October 26th, 11am, Zoom: Melanie Habouzit (MPIA) Recording
Massive Black Holes: Massive black holes of million solar mass and above are commonly hosted by massive galaxies, but are also present in local dwarf galaxies. Black holes are a fundamental component of galaxies and galaxy evolution, but their origin is still far from being understood. Large-scale cosmological hydrodynamical simulations are crucial to understand massive black hole growth and their interplay with their host galaxies. We recently compared the black hole population of six of these simulations and I will review how the simulation sub-grid models affect the build-up of the black hole population and their correlations with galaxies properties. The next two decades will be dedicated to the exploration of the high-redshift Universe with upcoming space missions such as JWST, Athena, LynX, Roman, and LISA. I will present how we can use cosmological simulations to prepare these missions and maximize their scientific return.
Tues November 2nd, 11am, Zoom: Jonelle Walsh (Texas A & M) Recording
The Supermassive Black Hole – Galaxy Connection: Over the past 20 years it has become increasingly clear that supermassive black holes are essential components of galaxies, as demonstrated by the correlations connecting black hole masses and large-scale galaxy properties. Although about ~100 dynamical black hole mass measurements have been made to date, the local black hole mass census is highly incomplete. Gaining a more complete picture of black hole demographics and a deeper understanding of the mechanisms that drive black hole – galaxy co-evolution requires the measurement of black holes in a wider range of galaxy types with diverse evolutionary histories. In this talk, I will describe a Gemini Large and Long Program aimed at addressing a bias in the types of galaxies for which black hole mass measurements have been made. I will also discuss an ALMA program where we are obtaining gas-dynamical black hole mass measurements for massive early-type galaxies, including a population of local galaxies that show remarkable similarities to galaxies observed at earlier epochs in the Universe.
Tues November 9th, 11am, Zoom: Kathryn Neugent (U. of Toronto) Recording
The Binary Fraction of Red Supergiants … and Beyond!: The binary fraction of massive main-sequence OB stars is thought to be as high as 70% or greater. However, until recently, only around a dozen binary red supergiants (RSGs) had been identified, despite the fact that these stars are the evolved descendants of a large portion of OB stars. My research focuses on searching for these “missing” binary RSGs. As dictated by stellar evolution, binary RSGs will likely have B-type companions and such systems will have unique photometric signatures due to the shape of their spectral energy distributions. After observing candidate RSG+B star binaries spectroscopically in the Local Group galaxies of M31, M33 and the Magellanic Clouds, we’ve discovered over 250 new systems. In this talk I’ll discuss how these results have allowed us to place constraints on the binary fraction of RSGs as a function of metallicity, and the greater impacts this has on our understanding of massive star evolution, supernovae populations, and the creation of gravitational wave events.
Tues November 23rd, 9am, Zoom: Irene Pintos-Castro (U. of Toronto) Recording
Clusters of Galaxies: studying environment & evolution: Galaxy clusters are the largest gravitationally bounded objects in the Universe, which makes them useful cosmological probes, but also great laboratories to study galaxy evolution. They host hundreds of galaxies belonging to two different populations: the red passive sequence and the blue star-forming (SF) cloud. We studied the SF population of galaxies within a sample of ∼200 IR-selected galaxy clusters at redshift 0.3 to 1.1 in two SpARCS fields, exploiting data from the deep layer of the Hyper Supreme-Cam Subaru Strategic Program (HSC-SSP). We observed an accelerated growth of the quiescent population within the cluster environment and found that environmental and mass quenching efficiencies depend on galaxy stellar mass and distance to the centre of the cluster, indicating that the two effects are not separable in the cluster environment. Here, we demonstrated how the large area and depth of these data allowed us to analyze the dependence of the SF fraction on stellar mass and environment separately. However, to deepen further into the effect of the environment, a larger sample is needed. Within this context I will introduce the Observatorio Astrofisico de Javalambre (OAJ) and its main surveys: J-PLUS and J-PAS.
Tues November 30th, 11am, Zoom: Matthew Quenneville (Berkeley) Recording
Measuring Supermassive Black Hole Masses with Triaxial Orbit Modelling: Massive elliptical galaxies have been found to host some of the largest supermassive black holes (SMBHs) in the nearby universe. Accurate dynamical measurements of these black holes are essential for determining the local SMBH-galaxy scaling relations which underpin our understanding of SMBH masses throughout the universe. Of the small number of galaxies that have been modelled while allowing for triaxial shapes, several have shown SMBH mass estimates that are dramatically different from those determined using axisymmetric models. I will discuss the dynamics of stars within a triaxial galaxy and our recent progress in advancing a triaxial orbit code. Together with a novel grid-free sampling technique, we can now efficiently search the high-dimensional parameter space to determine a galaxy’s SMBH mass, stellar mass-to-light ratio, dark matter content, and 3D intrinsic shape simultaneously.
Tues December 7th, 11am, Zoom: Rebecca Bowler (Oxford) Recording
Bright galaxies in the first billion years: Studying galaxies at ultra-high redshifts (z > 6) provides a unique insight into the early stages of galaxy formation and evolution. I will give an overview of how star-forming ‘Lyman-break’ galaxies are selected in the first few billion years. I will then show how samples of these objects can constrain the astrophysics at play in early galaxy formation through the observed shape and evolution of the luminosity function. Finally I will present some of the first resolved measurements of the young stars and dust within normal galaxies in the Epoch of Reionization. These results give a sneak preview of the exciting discoveries upcoming from JWST, as well as Euclid and Roman, on the earliest stages of galaxy formation and evolution.
Tues December 14th, 11am, Zoom: Laurie Rousseau-Nepton (CFHT) Recording
SIGNALS: Learning on the Birth of the Stars with SITELLE: October 2018 marked the beginning of a new large program at the Canada-France-Hawaii Telescope: SIGNALS, the Star-formation, Ionized Gas, and Nebular Abundances Legacy Survey. During the next four years and with 60 nights of telescope time in hands, our collaboration is observing more than 50,000 extragalactic star-forming regions located in different galactic environments using the instrument SITELLE, a Imaging Fourier Transform Spectrograph. In order to build this sample, we cover 40 galaxies that are actively forming stars within a distance of 10 Mpc. SITELLE was build in Canada and is the perfect instrument to survey these often extended objets. With SIGNALS, we are seeking to increase our knowledge on how stars form in galaxies, how their birthplace affects their properties, and how multiple generations of stars transform galaxies. Stars continuously affect their environment by returning new elements to the interstellar gas. These new elements are then recycled to form new stars. Stars form in a wide variety of environments. These can be different galaxy to galaxy, location to location. The result is that each star has its own story. By studying 50,000 regions where stars actively form, we will understand what triggers their formation, how efficiently stars form, and how each generation transforms the gas around them. This will also help researchers to understand the star-formation history of the whole Universe since the Big-Bang. During this presentation, I will introduce this ambitious project and the instrument SITELLE as well as show some preliminary results.
Spring/Summer 2021
Tues March 23rd, 11am, Zoom: Meredith Macgregor (U. of Colorado Boulder) Recording
How to Form a Habitable Planet: More than 20% of nearby main sequence stars are surrounded by debris disks, where planetesimals, larger bodies similar to asteroids and comets in our own Solar System, are ground down through collisions. The resulting dusty material is directly linked to any planets in the system, providing an important probe of the processes of planet formation and subsequent dynamical evolution. The Atacama Large Millimeter/submillimeter Array (ALMA) has revolutionized our ability to study planet formation, allowing us to see planets forming in disks and sculpting the surrounding material in high resolution. I will present highlights from ongoing work using ALMA and other facilities that explores how planetary systems form and evolve by (1) connecting debris disk structure to sculpting planets and (2) understanding the impact of stellar flares on planetary habitability. Together these results provide an exciting foundation to investigate the evolution of planetary systems through multi-wavelength observations.
Tues March 30th, 11am, Zoom: Hanno Rein (U. of T) Recording
Chaos, Instability, and Machine Learning: We have known the equations which determine the trajectories of planets for over 300 years. Yet, the long term evolution of the Solar System was not well understood until just a few years ago. In this talk, I will explain why it is so hard to solve these differential equations and describe the recent algorithmic breakthroughs that have made such problems tractable. These new numerical tools allow us to address many exciting scientific questions. I will outline some of my current research projects which aim to improve our understanding of planet formation in our galactic neighbourhood, and put constraints on General Relativity on timescales of billions of years. I will also present how we construct a Bayesian neural network to accurately predict instabilities orders of magnitudes faster than was possible before. This model enables us to include stability constraints in data reduction pipelines for extrasolar planetary systems.
Tues April 6th, 11am, Zoom: Tuan Do (UCLA) Recording Unavailable
The Galactic Center: a laboratory for the study of the physics and astrophysics of supermassive black holes: The center of the Milky Way hosts the closest supermassive black hole and nuclear star cluster to the Earth, offering us the opportunity to study the physics of supermassive black holes and their environment at a level of detail not possible elsewhere. I will discuss 2 major questions that are at the forefront of Galactic center research: (1) What is the nature of the near-infrared emission from Sgr A*? and (2) How do nuclear star clusters form and evolve in the vicinity of a supermassive black hole? I will show how the long time-baseline of Galactic center observations, improved instrumental capabilities, and use of statistical methods to combine many types of data have led us to new insights into these questions. I will discuss what we have learned in 20 years of observations of the supermassive black hole, Sgr A*, in the near-infrared and its surprising increase in activity in recent years. I will also discuss how the results the first chemical-dynamical model of the Milky Way Nuclear Star Cluster allow us to disentangle its complex formation.
Tues April 13th, 11am, Zoom: Deep Anand (U. of Hawaii) Recording
Tues April 20th, 11am, Zoom: Auriane Egal (Western U.) Recording
Comet Halley’s twin meteor showers: 1P/Halley is a famous comet that aroused the interest of the general public and the scientific community for several centuries. Its most recent apparition in 1986 motivated an unprecedented observational effort, combining spacecraft rendezvous and ground-based telescopic programs led by different countries. Most of our knowledge about the comet’s activity and evolution comes from the results of this exceptional observation campaign. From the analysis of ancient Chinese and Babylonian inscriptions, we suspect that 1P/Halley has been delivering meteoroids to Earth for several millennia. In particular, the comet is known to produce two meteor showers at the present epoch, the Eta-Aquariids in May and the Orionids in October. However, and despite decades of meteor observations, most of the showers’ characteristics are still unexplained. In this presentation, we expose the results of a new numerical model of 1P/Halley’s meteoroid streams, allowing to reproduce the meteor showers’ formation, intensity, duration, and predict the apparition of future meteor outbursts to watch. In particular, we expect three Eta-Aquariids outbursts in the future that deserves special attention.
Tues April 27th, 11am, Zoom: Oliver Müller (U. of Strasbourg) Recording
A cosmic ballet of dwarf galaxies as challenge for dark matter cosmology: Dwarf galaxies are not only the most common galaxies but also the most dark matter dominated objects in the universe. By studying their abundance and distribution, we can test our current model of cosmology. Around the Milky Way and the Andromeda – the Local Group –, several discrepancies between observations and the predictions for these dwarf galaxies have been identified, constituting a small-scale crisis. The most severe of them is the plane-of-satellites problem: the dwarf galaxy satellites around the Milky Way and the Andromeda are aligned in thin, planar, co-rotating structures. This is in stark contrast to the results of cosmological simulations, where for the satellite system an isotropic distribution with random motions is expected. This raises the question: Is the Local Group unique? Recent observations of the nearby Centaurus group say it is not. In my talk, I will give a review over the current state of this peculiar question in near-field cosmology.
Tues May 4th, 11am, Zoom: Judit Prat (DES/U. of Chicago) Recording
Galaxy-galaxy lensing and Lensing Ratios for Cosmological Analyses in the Dark Energy Survey: Galaxy cosmic surveys such as the Dark Energy Survey are a powerful tool to extract cosmological information. In particular, the combination of weak lensing and galaxy clustering measurements, usually known as 3x2pt, provides a potent and robust way to constrain the parameters controlling the structure formation in the late Universe. Galaxy-galaxy lensing, which is the cross-correlation of the shapes of source background galaxies with lens foreground galaxy positions, is one of the three probes that is part of this combination. In this talk, I will describe how we can accurately measure and model galaxy-galaxy lensing correlations using the well-understood large scales with the purpose of extracting cosmological information. Besides this, I will also describe how we can construct suitable ratios of these measurements to exploit the otherwise usually disregarded small-scale information and naturally integrate it as a part of the 3x2pt analysis.
Tues May 25th, 11am, Zoom: Carl Fields (MSU/Arizona/LANL) Recording
Next-Generation Simulations of The Remarkable Deaths of Massive Stars: Core-collapse supernova explosions (CCSN) are one possible fate of a massive star. Simulations of CCSNe rely on the properties of the massive star at core-collapse. As such, a critical component is the realization of realistic initial conditions. Multidimensional progenitor models can enable us to capture the chaotic nuclear shell burning occurring deep within the stellar interior. I will discuss ongoing efforts to progress our understanding of the nature of massive stars through next-generation hydrodynamic stellar models. In particular, I will present recent results of three-dimensional hydrodynamic massive star models evolved for the final 10 minutes before collapse. These recent results suggest that realistic 3D progenitor models can be favorable for obtaining robust models of CCSN explosions and are an important aspect of massive star explosions that must be taken into consideration. I will conclude with a brief discussion of the implications our models have for predictions of multi-messenger signals from CCSNe.
Tues June 1st, 11am, Zoom: Yamila Miguel (Leiden) Recording
Unveiling the secrets of Jupiter with the Juno mission: With more than 4000 exoplanets found and about 2-dozens of planets with detected atmospheric chemical species, we moved from an era of discovery to a new era of exoplanet characterisation. On the other hand, extremely accurate measurements by Juno and Cassini missions, make this an exceptional time to combine the detail information on the solar system giant planets and the large amount of data from exoplanets to get a better understanding on planetary physics and a better comprehension on planet formation and evolution. Because our knowledge on the interior structure of the giant planets is linked with the data we obtain from space missions, these last years were crucial for this field: the outstanding accuracy of the gravity data provided by Juno has fundamentally changed our understanding of the interior of Jupiter. It has allowed us to put constrains on the zonal flows, the extent of differential rotation and lead us to find that Jupiter has most likely a dilute core. In this presentation I will review our knowledge on the interior structure of Jupiter and will also show some new results where we find that a non-homogenous envelope is also a constraint set up by the Juno measurements, which is helping us to get closer to unveiling Jupiter’s deep secrets and to reach a better understanding of the giant planets formation history.
Tues June 8th, 11am, Zoom: Shany Danieli (IAS) Recording
Towards a better understanding of low mass galaxies beyond the Local Group: Low mass galaxies provide an essential testing ground for theoretical predictions of cosmology. Their number densities, structures, and internal dynamics can be extremely insightful for studying dark matter and galaxy formation on small scales. I will discuss recent results studying dwarf galaxies and ultra-diffuse galaxies (UDGs). UDGs hold the promise of new constraints on low mass galaxies dynamics, as their spatial extent and often significant globular cluster populations provide probes on spatial scales where dark matter should dominate the kinematics. I will also discuss the dynamics of two UDGs that seem to lack most, if not all, of their dark matter and host an intriguing population of globular clusters. I will finish by presenting a new wide-field survey carried out with the 48-lens Dragonfly Telephoto Array. With an excellent photometric depth, the Dragonfly Wide Field Survey will provide an unprecedented view of the low surface brightness universe over a wide area of the sky (350 square degrees). The main goal of the survey is to provide information on the properties and statistics of the dwarf galaxy population beyond the Local Group but it will also provide a useful resource for other resolved, low surface brightness phenomena, such as stellar streams and tidal tails, stellar halos, intragroup light and the extent of massive galaxies.
Tues June 22nd, 11am, Zoom: Jane Huang (U. of Michigan) Recording
The ALMA View of Planet Formation: The ubiquity and diversity of planets tell us that they can emerge under an astonishing range of conditions. By enabling us to map the distributions of dust grains and molecules in protoplanetary disks at an unprecedented level of detail, the Atacama Large Millimeter/Submillimeter Array (ALMA) has transformed our understanding of planet formation. In the Disk Substructures at High Angular Resolution Project (DSHARP), we undertook the first high angular resolution disk survey at millimeter wavelengths. Although protoplanets are difficult to detect directly, the widespread presence of dust gaps and rings in disks suggests that giant planet formation may occur readily on Myr-timescales at surprisingly wide separations. Meanwhile, in a small but growing number of systems, detections of puzzling spiral structures oblige us to re-examine common assumptions about the reservoir of material available for planet formation. ALMA has also revealed strong chemical heterogeneity within and among disks, laying the observational groundwork for linking the compositions of planets to their formation location. Together, these new data show that the natal environments of planets are far more dynamic and varied than earlier observations have indicated.
Winter 2021
Tues January 19th, 11am, Zoom: Kim-Vy Tran (UNSW) Recording
MOSEL & ZFIRE : Tracking Galaxy Growth at Cosmic Noon: MOSEL and ZFIRE are deep near-IR spectroscopic surveys that track how galaxies assemble at 1.5<z<3.5. With MOSEL, we confirm a population of Extreme Emission Line Galaxies at z~3 with Oxygen equivalent widths >250 Angstroms and hypothesize that most galaxies at z>3 go through a strong starburst phase. We compare galaxy kinematics to IllustrisTNG to determine how massive galaxies at z~3 build their stellar mass (mostly by accreting other galaxies) and end their star formation (puffy galaxies quench slower). I also summarize results from our ZFIRE survey where we find faint imprints of environmental effects on the Inter-Stellar Medium of cluster galaxies at z~2.
Tues January 26th, 4pm***, Zoom: Takuma Izumi (NAOJ) Recording
ALMA observations of z > 6 low-luminosity quasars: unbiased view on the early co-evolution and feedback: I will review our multi-wavelength campaign observations toward z > 6 optically “low-luminosity” quasars, which were originally discovered by our wide-field Subaru Hyper Suprime-Cam (HSC) optical imaging survey. Our HSC quasars are an order of magnitude fainter at rest-UV than previously-known luminous quasars. Subsequent NIR spectroscopic follow-up observations revealed a wide spread in their BH mass, hence Eddington ratio (~0.1 to 1). We have also been carrying out a series of ALMA observations ([CII] line and FIR continuum emission) toward a sample of ~20 HSC quasars. We found that their host galaxies are basically FIR-faint with LIRG-class luminosities (or SFR < 100 Msun/yr). Using the [CII]-based dynamical mass as a surrogate for bulge stellar mass, we found that a significant fraction of these low-luminosity quasars are located on or even below the local co-evolution relation, indicating the BH-galaxy co-evolution is indeed taking place at z > 6. I also talk about a particular case of a z = 7.1 HSC quasar, where we found a vigorous starburst and, surprisingly, fast [CII] outflows. Given also its broad absorption line = BAL feature (indication of nuclear outflow), quasar-driven feedback that affects the host galaxy occurred already at this reionization era.
Tues February 2nd, 11am, Zoom: Ilse Cleeves (U. of Virginia) Recording
The key role of astrochemistry in driving planet formation and habitability: Historically, our perspective on how planets form and obtain their compositions has been motivated by our Solar System. However, we are just one system, and missions like Kepler and TESS have revealed a variety of planetary types and architectures. How do we fit in? In the last five years, the Atacama Large Millimeter Array has revolutionized our understanding of planet formation by observing the process at high spatial resolution (reaching in some cases ~AU scales) matched with unprecedented sensitivity at radio wavelengths. In this presentation, I will review recent highlights from the TW Hya as a Chemical Rosetta Stone ALMA project and discuss how these findings both confirm and, in some ways, challenge our current picture of the chemistry of planet formation.
Tues February 16th, 11am, Zoom: Genaro Suarez (Western U.) Recording
An Accurate Look at the L-to-T Spectral Type Transition: I will present the most comprehensive spectral energy distribution (SED) of a young brown dwarf at the L/T transition by combining new Spitzer mid-infrared spectra and photometry with previous observations of HN Peg B. We use this SED to evaluate the performance of various atmospheric models and found that models with condensates and using non-equilibrium chemistry reproduce better the data. However, these models face challenges in reproducing the observed methane and carbon monoxide absorption strengths mainly over the 3–5 um region. By using the assembled SED and the Gaia EDR3 parallax of the host star, we derive accurate fundamental parameters of HN Peg B. We find that, in comparison to older early T dwarfs in the field, HN Peg B is ≈100 K cooler, has a ≈ 13% larger radius, and has a consistent bolometric luminosity. A comparison among moderate-dispersion near-infrared spectra of HN Peg B and other young and old dwarfs with similar spectra types shows that the 1.25-micron potassium line strengths are mostly insensitive to surface gravity in early-T dwarfs.
Tues February 23rd, 3pm***, Zoom: Emily Wisnioski (ANU) Recording
The resolved dynamics and metallicity of galaxies across cosmic time: I will discuss the formation and evolutionary paths of star-forming galaxies. Kinematics and chemical properties have revealed that the majority of star-forming galaxies at ‘comic noon’ host thick disk-like structure and a turbulent less enriched interstellar medium. I will present results utilising synergies with multi-wavelength ground and space-based surveys to trace the evolution of spatially-resolved dynamics and star formation from a homogeneous sample over 5 billion years of cosmic history. These results when combined with local galactic archeology studies and new analytic models provide insights into how the structures of local galaxies including the Milky Way were formed. I will discuss the observational results within the framework of theoretical models for the formation of gas phase metallicity gradients and the local stellar age-velocity dispersion relation.
Tues March 9th, 11am, Zoom: Laura Keating (AIP) Recording
Insights into the epoch of reionization from quasar absorption lines: The epoch of reionization marks the last major phase transition of the Universe, when photons emitted by the first structures ionized and heated the gas surrounding them. A complete understanding of reionization would reveal the properties of the first stars and galaxies, as well as increasing the precision to which the high-redshift intergalactic medium can be used to constrain cosmological parameters. In this talk I will demonstrate that the the pattern of absorption lines seen in distant quasars, known as the Lyman-alpha forest, is an ideal tool to study reionization. I will present results from cosmological radiative transfer simulations, which were carefully calibrated to reproduce the statistics of the Lyman-alpha forest, and will show that matching the observations requires reionization to have ended much later than previously thought.
Tues March 16th, 1pm***, Zoom: JJ Eldridge (U. Auckland) Recording
Some of the things binary stars do…. Most of the stars in the Universe are not single like our Sun but in binary stars systems. A binary star is composed of two stars in orbit around each other, as they age they can “get-in-each-others” way and experience very different evolution to that our stars like our Sun. Only over the last decade it has become clear that to accurately understand the Universe we need to take account of these interacting binary stars. In my talk I will go over a few examples showing how understanding binary stars allows us to understand the appearance of galaxies, the diversity of supernovae, the production of the most abundant and rarest elements and discuss the latest LIGO/VIRGO O3a results and their implications for binary evolution.
Fall 2020
Tues September 15th, 11am, Zoom: Silvia Toonen (U. of Birmingham) Recording
Stellar interactions and transients: In order to understand the Universe we live in, we must understand the diverse lives of stars, the fundamental building blocks of galaxies and stellar clusters. However, most stars do not evolve in isolation; they have one or more stellar companions that they can interact with. These interactions give rise to some of the most energetic events in the universe, e.g. stellar mergers, supernovae Type Ia explosions and gravitational wave sources. The last decade has revealed the existence of a large and diverse zoo of transients, but their origin or progenitor evolution is often unknown. In this talk I will show novel channels to induce stellar interactions and subsequent transients. I will present our latest results regarding the evolution of white dwarf binaries and their mergers, with implications for Galactic archaeology. Secondly, I will discuss how triple stars can evolve differently from binary stars, and show their potential as transient progenitors. While triple star systems are common, our understanding of their evolution has lagged behind compared to single and binary stars. I will conclude with revealing a new primary channel of binary evolution towards supernova type Ia events.
Tues September 22nd, 11am, Zoom: Fabio Pacucci (Harvard) Recording
Detecting the Dawn of Black Holes: In this talk I discuss the quest to unravel two undetected populations of high-z black holes. The first population of black holes formed when the age of the Universe was less than 500 Myr, while by z=7 we have observations of fully-fledged, shining quasars. Shedding light on this cosmic period is one of the key tasks that the astronomical community will focus on in the next decade, due to its crucial importance for the early evolution of the Universe.The observational signatures of black hole seeds remain largely unexplored, and we are yet to detect these sources. I present detailed predictions for the spectra of different categories of seeds, and a photometric method to identify them in surveys. I explore the role that future facilities (e.g., JWST, Athena, Lynx, LISA) will play in this quest, by detecting both black hole accretion and mergers. To conclude, I show a detailed analysis of the requirements and the expectations for a comprehensive search of z > 10 black hole seeds. Moving at slightly lower redshifts, the discovery of the first strongly lensed quasar at z > 6 (J0439+1634, Fan et al. 2018) represents a breakthrough in our understanding of the early Universe. Pacucci & Loeb (2018) predict that the observed population of z > 6 quasars should contain many mildly magnified sources, with image separations below the resolution threshold. Additionally, current selection criteria should have missed a substantial population of lensed z > 6 quasars: WFIRST will likely play a crucial role in revealing this population. I estimate the fraction of undetected quasars as a function of the slope of the bright end of the quasar luminosity function. For steep values of this parameter, the vast majority of the z > 6 quasar population is lensed and still undetected. These “phantom quasars” would be misclassified and mixed up with low-z galaxies. I conclude by addressing how gravitational lensing can affect the inferred black hole mass distributions at z > 6, possibly having important implications for current theories of growth for early quasars.
Tues September 29th, 11am, Zoom: Benne Holwerda (U. of Louisville) Recording
A Search for High-Redshift Galaxies And An Accidental Galactic Survey of Dwarf Stars with Hubble: Current searches for high-redshift galaxies use a combination of near-infrared filters with one or more optical filters to check for contaminants. One of these contaminants are faint dwarf stars in the disk and halo of our own Milky Way Galaxy. Thus in the search for the galaxies that caused the Reionization of the Universe, an accidental census of Dwarf stars in the Milky Way was conducted as well. I report on one observational approach with the Hubble Space Telescope; the Brightest Origin of Reionizing Galaxies (BORG) survey. I will discuss the identification of the distant high-redshift galaxies, their unique properties, the faint brown and red dwarf stars (M-dwarfs) and our results on characterizing the shape of the Milky Way from their number. We identified stellar objects in the BoRG survey and mapped their distribution onto the Milky Way. Results are a thin disk (300pc), the rediscovery of the Sagittarius stream, a total count of 58 billion M-dwarfs in the Milky Way of which 7% reside in the halo. We also found a population of very bright, redshift eight galaxies (“Super-Eights”) that show evidence for strong nebular emission lines and direct observations of Lyman-alpha. The Super-Eights appear to reveal a very specific mode of star-formation that may have played a critical role in the Reionization of the Universe.
Tues October 6th, 11am, Zoom: Vivienne Baldassare (Washington State U.) Recording
Searching for active galactic nuclei in low-mass galaxies via optical variability: The present-day population of supermassive black holes in low-mass galaxies offers a window into massive black hole formation in the early universe. While we cannot yet observe the formation of “black hole seeds” at high redshift, the fraction of small galaxies that host a supermassive black hole — and the properties of those black holes — are thought to depend on the mechanism by which these they form. However, black holes in the smallest galaxies can be difficult to find, requiring creative new approaches. I will discuss recent work showing that long-term optical photometric variability in low-mass galaxies can identify active galactic nuclei that are missed by other selection techniques. I will present an analysis of the nuclear variability of more than 70,000 nearby galaxies and discuss our sample of low-mass, variability-selected supermassive black holes. Using this sample, we are also able to place meaningful constraints on the present-day black hole occupation fraction at low galaxy stellar masses.
Tues October 13th, 3pm***, Zoom: Madeline Marshall (HAA) Recording
The Host Galaxies of High-Redshift Quasars: Studying the host galaxies of high-redshift quasars provides vital insights into the early growth of supermassive black holes and the black hole—galaxy connection. Here I present an analysis of the properties and environments of the host galaxies of z=7 quasars from the BlueTides hydrodynamical simulation. I will also show our latest work using HST to obtain upper limits on the UV emission of z~6 quasar host galaxies. In combination, these two techniques will help to pave the way for making the first near-infrared detections of high-redshift quasar hosts with JWST.
Tues October 20th, 11am, Zoom: Greg Mosby (NASA) Recording
Estimating star formation histories from galaxy spectra and the path to life finding NIR detectors: The evolution of galaxies can be conveniently broken down into the evolution of their contents. We focus on the stellar content that can be observed, as the stars reflect information about the galaxy when they were formed. We approximate the stellar content and star formation histories of unresolved galaxies using stellar population modeling. We can use stellar population modeling of galaxies to test galaxy evolution and formation models. However, in the limit of low galaxy surface brightness, integrated spectra often have such low S/N that it hinders analysis with standard stellar population modeling techniques. To address this problem, we have developed a method that can recover galaxy star formation histories (SFHs) from rest frame optical spectra with S/N ~ 5 Å^-1 with a specific application to quasar host galaxies. We use the machine learning technique diffusion k-means to tailor the stellar population basis set, composed of 4 broad age bins, and it is successful in recovering a range of galaxy SFHs. Our method has the advantage in recovering information from quasar host galaxies and could also be applied to the analysis of other low S/N galaxy spectra such as that typically obtained for high redshift objects and integral field spectroscopic surveys. I have now begun using diffusion k-means to generate a multi-metallicity basis set to estimate the stellar mass and chemical evolution of unresolved galaxies. In addition, I have begun work to fully characterizing today’s HgCdTe photodiode arrays to lay the foundation for future near infrared detector development. Low read noise and well-characterized detectors are crucial in the emerging search for biosignatures in exoplanet atmospheres.
Tues October 27th, 11am, Zoom: Monika Soraisam (U. of Illinois at Urbana-Champaign) Recording
Tues November 17th, 11am, Zoom: Davide Farnocchia (JPL/CalTech) Recording Unavailable
OSIRIS-REx and impact hazard assessment for asteroid (101955) Bennu: The OSIRIS-REx mission is part of NASA’s New Frontiers Program and is the first U.S. mission to retrieve a sample of an asteroid and carry it to Earth for further study. The target of OSIRIS-REx (101955) Bennu, a 500 m near-Earth asteroid that is expected to have organic compounds and water-bearing materials. OSIRIS-REx launched in September 2016 and rendezvoused with Bennu in late 2018. After two years of proximity operations, on 2020 October 20 OSIRIS-REx successfully executed the sample collection sequence and is now preparing for the return cruise to Earth to deploy the sample in 2023. In this talk, I will present the current status of the mission, highlighting some the main challenges faced by the mission and the most relevant scientific results. In particular, I will focus on the impact hazard problem. Bennu is a potentially hazardous asteroid and its trajectory is deterministic until the close approach with Earth in 2135. After this encounter, the orbital uncertainty of Bennu increases to a level that its trajectory can only be analyzed in a statistical sense, and impacts with Earth cannot be ruled out in the second part of the next century. Key to the modeling of Bennu’s trajectory is the Yarkovsky effect, a subtle nongravitational perturbation due to non-isotropic thermal radiation that causes a semimajor axis drift. The OSIRIS-REx tracking data provide useful constraints on this perturbation and on the Bennu hazard assessment.
Tues November 24th, 11am, Zoom: Ian Roederer (U. of Michigan) Recording
The astrophysical r-process: what we are learning from gravitational waves, dwarf galaxies, and stellar archaeology: Understanding the origin of the elements is one of the major challenges of modern astrophysics. The rapid neutron-capture process, or r-process, is one of the fundamental ways that stars produce the heaviest elements, but key aspects of the r-process are still poorly understood. I will describe four major advances in the last few years that have succeeded in confirming neutron star mergers as an important but perhaps not exclusive site of the r-process. These include the detection of freshly produced r-process material powering the kilonova associated with the merger of neutron stars detected via gravitational waves (GW170817), the identification of a dwarf galaxy where most of the stars are highly enhanced in r-process elements (Reticulum II), new connections between the r-process and its Galactic environment (thanks to data from the Gaia satellite), and advances in deriving abundances of previously-undetected r-process elements (such as Se, Te, Pt) in ultraviolet spectra of metal-poor stars. I will highlight opportunities to connect these research directions with future facilities (like FRIB, CETUS, and HabEx) to associate specific physics with specific sites of the r-process.
Tues December 1st, 11am, Zoom: Feige Wang (U. of Arizona) Recording
Tues December 8th, 11am, Zoom: Stanimir Metchev (Western U.) Recording
Micro- and nano-satellites offer cost-effective platforms for space technology development and for targeted investigations in astronomy: As demonstrated by MOST and BRITE, time-domain photometry of bright objects, such as Milky Way stars and planetary systems, can be well-served by their modest apertures. Improving detector technology is now opening small-sat platforms to fainter extragalactic objects, to non-optical wavelengths, to multi-band photometry, low-resolution spectroscopy, and polarimetry. Two novel opportunities have been explored through recent studies for the CSA. The Photometric Observations of Extrasolar Planets (POEP) mission aims for dedicated UV and near-IR capability on a 15 cm telescope to characterize atmospheric scattering in exoplanetary atmospheres and to detect Earth-sized planets around red dwarfs. POEP has been endorsed as a highly-ranked LRP2020 space astronomy priority in the <$25M category, behind only continued support for JWST. The Extrasolar Planet Polarimetry Explorer (ÉPPÉ) aims to be the first space mission designed specifically for precision polarimetry. Differential polarimetric observations with ÉPPÉ would be sensitive to tenuous amounts of atmosphere on known exoplanets, and in particular to highly-polarizing volatiles, such as water, methane, etc. Both POEP and ÉPPÉ would offer unique capabilities that would complement well the suite of large space telescopes anticipated at the end of this decade. Given Canada’s astronomy small sat heritage, it is in a strong position to lead these new developments.
Summer 2020
Tues May 12th, 11am, Zoom: Evelyn Johnston (Universidad Católica)
Tues May 19th, 11am, Zoom: Paul Wiegert (Western University)
Tues June 2nd, 11am, Zoom: Decker French (Carnegie Observatories), Recording
Tues June 9th, 11am, Zoom: Raja GuhaThakurta (Santa Cruz/Lick Obs.), Recording
Tues June 16th, 11am, Zoom: Peter Brown (Western University), Recording
Tues June 23rd, 11am, Zoom: Ylva Gotberg (Carnegie Observatories), Recording
Tues June 30th, 4pm**, Zoom: Daniel Price (Monash University), Recording
Tues July 7th, 11am, Zoom: Meg Schwamb (Queen’s U Belfast), Recording
Tues July 14th, 11am, Zoom: Jan Cami (Western University), Recording
Winter 2020
Tues January 14th, 11am, LCR: Marcin Sawicki (St Mary/HAA)
Tues January 21th, 11am, LCR: Jay Melosh (Perdue University)
Tues February 4th, 3pm, LCR: David Hendel (University of Toronto)
Tues February 11th, 11am, LCR: Brian Svaboda (NRAO New Mexico)
Tues February 18th, 11am, LCR: Sarah Sadavoy (Queens University)
Tues February 25th, 11am, LCR: Gijs Mulders (University of Chicago)
Tues March 3rd, 11am, LCR: Ilse Cleeves (University of Virginia) Cancelled/Postponed due to travel restrictions
Tues March 10th, 11am, LCR: Daryl Haggard (McGill University)
Tues March 17th, 11am, LCR: Greg Mosby (NASA Goddard) Cancelled/Postponed due to travel restrictions
Tues March 24th, 11am, LCR: Fabio Pacucci (CfA/Harvard) Cancelled/Postponed due to travel restrictions
Tues March 31th, 11am, LCR: Mehrnoosh Tahani (DRAO) Cancelled/Postponed due to travel restrictions
Fall 2019
Tues September 17th, Todd Henry (Georgia State University)
Tues September 24th, Eve Lee (McGill)
Mon October 7th, Satoshi Yamamoto (University of Tokyo)
Tues October 15th Gwendolyn Eadie (University of Toronto)
Tues October 22nd, Tyrone Woods (HAA)
Tues October 29th, Isabel Santos-Santon (Univeristy of Victoria)
Tues November 5th, Library: Sarah Pearson (Flatiron institute)
Tues November 19th, Jennifer Marshall (MSE)
Tues November 26th, Brian Mason (Georgia State University)
Tues December 3th, Allison Man (Dunlap Institute)
Tues December 10th, Raphaël Errani (University of Victoria/CITA)
Spring 2019
Date | Speaker | Title / Topic (Click for poster/abstract) |
Tues Jan 8 | No seminar | (AAS week) |
Tues Jan 15 | Hope How-Huan Chen (UT Austin) | Coherent Structures and Star Formation: An Updated Story of Islands of Calmness in a Sea of Turbulence |
Tues Jan 22 | Renee Hlozek (Toronto) | The Photometric LSST Astronomical Time Series Classification Challenge |
Tues Jan 29 | Andrew Cumming (McGill) | Formation and evolution of gas giant planets and exoplanets |
Tues Feb 5 | Robyn Sanderson (UPenn) | Insights into dark matter from the stellar halos of galaxies |
Tues Feb 12 | — | Seminar cancelled due to weather. |
Tues Feb 19 | — | Seminar cancelled. |
**Thurs Feb 21** | Rory Barnes (U. Washington) | After the Habitable Zone |
Tues Feb 26 | Laura Fissel (NRAO) | Studying star formation from the stratosphere |
Tues Mar 5 | Sam Lawler (NRC/DAO) | Discoveries and Observation Biases in the Outer Solar System: Don’t Count Your Planets Before They Hatch |
Tues Mar 12 | Angie Wolfgang (Penn State) | What’s Next for Super-Earths? Population Demographics To Probabilistic Planetary Physics |
Tues Mar 19 | John Tobin (NRAO) | Revolutionizing our View of Disk and Multiple Star Formation: New Frontiers Explored by ALMA and the VLA |
**Wed Mar 20** | Yuan-Sen Ting (Princeton) | Milky Way, machine learning, big data |
Tues Mar 26 | Will Percival (Waterloo) | Making cosmological measurements with standard rulers and standard shapes |
Tues Apr 2 | Ruobing Dong (UVic) | Observational planet formation |
Tues Apr 9 | Wes Fraser (NRC) | |
Tues Apr 16 | No seminar | — |
Tues Apr 23 | Abedin Abedin (NRC) | |
Tues Apr 30 | TBD |
Fall 2018
Spring 2018
Date | Speaker | Title / Topic (Click for poster/abstract) |
Tues Jan 9 | Nienke van der Marel (NRC/DAO) | “The ALMA revolution of planet formation: structures of gas and dust in planet-forming disks” |
Tues Jan 16 | Rebecca Jensen-Clem (UC Berkeley) | “Probing the atmospheres of exoplanets and brown dwarfs with near-IR polarimetry” |
Tues Jan 23 | Alex Hill (UBC/DRAO) | “Ionization of the warm (magneto)ionized medium” |
Tues Jan 30 | Adrian Price-Whelan (Princeton) | “Very wide binaries and comoving stars in the Gaia era” |
Tues Feb 6 | Jocelyn Read (Cal State Fullerton) | “Measuring the neutron-star equation of state with GW170817” |
Tues Feb 13 | Reka Winslow (U. New Hampshire) | “Coronal mass ejection evolution and effects on galactic cosmic rays and planetary magnetospheres” |
Tues Feb 20 | Leslie Rogers (U. Chicago) | “The diversity and demographics of distant rocky worlds” |
Tues Feb 27 | Kelsi Singer (SwRI) | “From craters to cyrovolcanoes—Recent results from the New Horizons mission to Pluto and the Kuiper Belt” |
Tues Mar 6 | Evan Scannapieco (ASU) | “The rise and fall of galaxies” |
Tues Mar 13 | Tessa Vernstrom (Dunlap) | “The faint extragalactic radio background” |
Tues Mar 20 | Brenda Matthews (NRC/DAO) | “Debris disks and their connection to planets: Surveys and resolved imaging” |
Tues Mar 27 | Louise Edwards (Cal Poly SLO) | “Today’s largest galaxies: Examining the growth of local brightest cluster galaxies using IFU kinematics and stellar populations” |
Tues Apr 3 | Vincent Henault-Brunet (NRC/DAO) | “Mass modelling globular clusters: from black holes to low-mass stars” |
Tues Apr 10 | Guillaume Thomas (NRC/DAO) | “Testing the dark matter and alternative gravity theories with the stellar streams of the Milky Way” |
Tues Apr 17 | Lisa Locke (NRC/DAO) | “Phased Array Feeds etc.: Musings from the mm Instrumentation Group” |
Fall 2017
Date | Speaker | Title / Topic |
Tues. Sep. 5 | Henry Ngo (NRC/DAO) | “Planet Formation and Migration in Extreme Planetary Systems” |
Tues. Sep. 12 | Jessica Werk (UW) | “Circumgalactic Matter Matters” |
Tues. Sep. 19 | Dan Werthimer (UC Berkeley/SETI) | “Is Anyone Out There? SETI@home and the Breakthrough Listen Project” |
Tues. Sep. 26 | Yashar Hezaveh (Stanford) | “The Future of Mapping Dark Matter Structures with Strong Gravitational Lensing, New Surveys, and Machine Learning” |
Tues. Oct. 3 | Yancy Shirley (U. Arizona) | “Studying the Earliest Phase of Massive Star and Cluster Formation – the Properties of Massive Starless Clump Candidates in the Milky Way” |
Tues. Oct. 10 | *** No seminar *** | *** No seminar *** |
Tues. Oct. 17 | Hannah Jang-Condell (U. Wyoming) | “From Protoplanetary Disks to Exoplanets: How Do Planets Form and Evolve?” |
Tues. Oct. 24 | Karin Sandstrom (UC San Diego) | “Interstellar Dust at Low Metallicity” |
Tues. Oct. 31 | Charli Sakari (UW) | “Unraveling the Chemical Evolution of Galaxies Beyond the Milky Way with Integrated Light Spectroscopy of Globular Clusters” |
Tues. Nov. 7 | Courtney Dressing (UC Berkeley) | “Exploring Planetary Systems Orbiting Cool Dwarfs” |
Tues. Nov. 14 | Alessandro Boselli (LAM) | “The role of the environment on galaxy evolution and the VESTIGE survey” |
Tues. Nov. 21 | Bruce Macintosh (Stanford) | “The Gemini Planet Imager” |
Tues. Nov. 28 | Kevin Covey (Western Washington) | “Surveying the kinematics, multiplicity, and star formation histories of low-mass stars & Milky Way clusters with APOGEE” |
Spring 2017
Date | Speaker |
Jan 10 | Gary Mamon (IAP) |
Jan 17 | Alina Kiessling (JPL) |
Jan 24 | Chris Pritchet (UVic) |
Jan 31 | Cameron Yozin (UVic) ** cancelled ** |
Feb 7 | Karin Sandstrom (UC San Diego) |
Feb 14 | Erik Rosolowsky (U. Alberta) |
Feb 21 | Ian Shelton (Mount Allison) |
Feb 28 | Marc Buie (SwRI) |
Mar 7 | Sean Couch (Michigan State) |
Mar 14 | Catherine Espaillat (Boston) |
Mar 21 | Jessica Werk (UW) |
Mar 28 | Tim Davidge (NRC/DAO) |
Apr 4 | Matthew Payne (CfA/Harvard) |
Apr 11 | Jaime Pineda (MPE) |
Apr 18 | Dan Weisz (UC Berkeley) |
Apr 25 | Renu Malhotra (U. Arizona) |
Fall 2016
Date | Speaker |
Sep 06 | Gwen Eadie (McMaster) |
Sep 13 | Matthew Taylor (Universidad Catolica) |
Sep 20 | Quinn Konopacky (UC San Diego) |
Sep 27 | Lucas Macri (Texas A&M) |
Oct 04 | Jo Bovy (Toronto) |
Oct 11 | Keith Vanderlinde (Dunlap) |
Oct 18 | Tuan Do (UCLA) |
Oct 25 | Sean Andrews (CfA/Smithsonian) |
Nov 01 | Marta Volonteri (IAP) ** cancelled ** |
Nov 08 | Daniel Tamayo (Toronto) |
Nov 15 | Adam Ginsburg (NRAO) |
Nov 22 | Benoit Cote (UVic) ** cancelled ** |
Nov 29 | Katherine Kretke (SwRI) |
Dec 06 | Meredith Rawls (UW) |
Dec 13 | Paul Scholz (NRC/DRAO) |
Spring 2016
Date | Speaker |
Jan 19 | Karin Oberg (CfA) |
Jan 26 | Etsuko Mieda (NRC/DAO) |
Feb 02 | Nitya Kalliayalil (U. Virginia) |
Feb 09 | Richard Shaw (UBC) |
Feb 16 | David Nesvorny (SwRI) |
Feb 23 | Julie Hlavacek-Larrondo (UdM) |
Mar 01 | Cara Battersby (CfA) |
Mar 08 | Laura Sales (UC Riverside) |
Mar 15 | Michael Cooper (UC Irvine) |
Mar 22 | Betsy Mills (U. Arizona) |
Mar 29 | Emily Levesque (UW) |
Apr 05 | Will Grundy (Lowell) |
Apr 12 | Brett Gladman (UBC) |
Apr 19 | Linda Strubbe (UBC) |
Apr 26 | Anil Seth (U. Utah) |
May 03 | David Reitze (Caltech) |
May 24 | Sun Kwok (Hong Kong) |
Fall 2015
Date | Speaker |
Sep 15 | Mary Beth Laychak (CFHT) |
Sep 17 | Melissa Graham (UC Berkeley) |
Sep 22 | Dennis Crabtree (NRC/DAO) |
Sep 29 | Dustin Lang (CMU/Waterloo) |
Oct 06 | Elisabeth Mills (NRAO) |
Oct 13 | Roberto Abraham (Toronto) |
Oct 20 | David Gerdes (U. Michigan) |
Oct 27 | Ruth Murray-Clay (UC Santa Barbara) |
Nov 03 | Andrew Connolly (UW) |
Nov 10 | Jake Vanderplas (UW) |
Nov 17 | Jeffrey Fung (UC Berkeley) |
Nov 24 | Nicholas McConnell (NRC/DAO) |
Dec 01 | Gurtina Besla (U. Arizona) |
Dec 08 | Sarah Martell (UNSW) |
Spring 2015
Date | Speaker |
Jan 27 | Mark Krumholz (UCSC) |
Feb 03 | Jessica Lu (IfA) |
Feb 10 | Josh Eisner (U. Arizona) |
Feb 17 | Aaron Boley (UBC) |
Feb 24 | Michael Rupen (NRC/DAO) ** cancelled ** |
Mar 03 | Scott Chapman (Dalhousie) |
Mar 09 | Joe Masiero (JPL) |
Mar 17 | Meredith Hughes (Wesleyan) |
Mar 24 | Paul Schechter (MIT) |
Mar 31 | Lynne Hillenbrand (Caltech) |
Apr 07 | Mariska Kriek (UC Berkeley) |
Apr 14 | Kaitlin Kratter (U. Arizona) |
Apr 21 | Karun Thanjavur (UVic) |
Apr 28 | Chat Hull (CfA) |
Fall 2014
Date | Speaker |
Sep 02 | Elisa Toloba (UCO/Lick) |
Sep 03 | Guillermo Barro (UCO/Lick) |
Sep 09 | Luca Ricci (Caltech) |
Sep 16 | – |
Sep 23 | Eric Ford (Penn State) |
Sep 30 | Luc Simard (NRC/DAO) |
Oct 09 | Steve Majewski (U. Virginia) |
Oct 14 | Jon Swift (Caltech) |
Oct 21 | Luke Dones (SwRI) |
Oct 23 | Herzberg Jamboree |
Oct 28 | – |
Nov 04 | Florian Beutler (LBNL) |
Nov 11 | No seminar scheduled (holiday) |
Nov 18 | Alis Deason (UCO/Lick) |
Nov 20 | Shep Doeleman (MIT Haystack) |
Nov 25 | Claire Chandler (NRAO) |
Dec 02 | Rachel Friesen (Dunlap) |
Dec 09 | Kristine Spekkens (Queen’s) |
Dec 15 | cancelled |
Spring 2014
Date | Speaker |
Jan 14 | Arianna Di Cintio |
Jan 21 | John Wise |
Jan 28 | Alyson Brooks |
Feb 04 | Mike Landry |
Feb 11 | Rita Mann (NRC/DAO) |
Feb 18 | Luisa Rebull |
Feb 25 | Chris Friar |
Mar 04 | Christine Wilson (McMaster) |
Mar 11 | Rachel Mason |
Mar 18 | Juan Collar |
Mar 25 | Sam Lawler (NRC/DAO) |
Apr 01 | Karun Thanjavur (UVic) |
Apr 15 | Rachel Mason |
Apr 17 | Nienke van der Marel |
Apr 22 | Scott Sheppard |
May 06 | Philip Kronberg |
May 20 | Kevin Steels |
Fall 2013
Sep 17 Chris Stubbs
Sep 24 Hilke Schlichting
Oct 01 Donald Morton
Oct 08 Helen Kirk (NRC/DAO)
Oct 17 James Bullock (UC Irvine)
Oct 22 Riccardo Giovanelli
Oct 29 Ruben Sanchez-Janssen (NRC/DAO)
Nov 05 Michele Bannister (UVic)
Nov 12 Katherine Alatalo
Nov 19 Nitya Kallivayalil ** cancelled **
Nov 26 Diana Dragomir
Dec 03 Andy Becker
Dec 10 Inger Jorgensen
Spring 2013
Jan 29 Asa Bluck (UVic)
Feb 05 Miguel Morales
Feb 12 Jorge Moreno (UVic)
Feb 19 Erin Bonning
Feb 26 Jonathan Williams
Mar 05 Mike Boylan-Kolchin
Mar 12 Alex Kim
Mar 21 Tony Tyson
Mar 26 David Wilner
Apr 09 Joern Geisbeusch
Apr 16 Wes Traub
Apr 23 Paul Kalas
Apr 25 Yin-Zhe MA
Apr 30 Graca Roca
May 14 Brian McNamara (U. Waterloo)
May 21 Mubdi Rahman
Fall 2012
Aug 28 Andrea Kunder (CTIO)
Sep 04 Jennifer Karr (ASIAA) / Hiro Takami (ASIAA)
Sep 11 No Seminar Scheduled
Sep 18 Nicholas Ball (NRC/DAO)
Sep 25 Chris Reynolds (U. Maryland)
Oct 02 Ben Mazin (UC Santa Barbera)
Oct 09 Matthijs van der Wiel (U. Lethbridge)
Oct 16 Charlie Conroy (UC Santa Cruz)
Oct 23 Sarah Ballard (UW)
Oct 30 Susan Terebey (California State)
Nov 07 Shelley Wright (Dunlap)
Nov 13 Wesley Traub (JPL)
Nov 20 Norman Murray (CITA)
Nov 27 Tim Beers (NOAO)
Dec 04 Tim Robishaw (NRC/DRAO)
Spring 2012
Jan 17 David Tsang (Caltech)
Jan 24 Else Starkenburg (UVic)
Jan 31 Tommaso Treu (UC Santa Barbara)
Feb 07 Federica Bianco (LCOGT)
Feb 14 No Seminar Scheduled
Feb 23 Crystal Martin (UC Santa Barbara)
Feb 28 Scott Schnee (NRAO)
Mar 06 Trevor Mendel (UVic)
Mar 14 Stephen Kane (Caltech)
Mar 22 Peter Yoachim (UW)
Mar 27 Martin Bureau (U. Oxford)
Apr 03 Lynne Jones (UW)
Apr 10 Wes Fraser (NRC/DAO)
Apr 17 John Tobin (NRAO)
Apr 24 James Graham (Dunlap)
May 11 Faith Vilas (U. Arizona)
Jun 11 Giuseppina Battaglia (ESO/INAF)
Jun 14 Jeremy Mould (NOAO)
Fall 2011
Sep 13 Sarah Loebman (UW)
Sep 20 Bob Rood (U. Virginia)
Sep 27 Kate Su (Steward)
Oct 04 Sarah Brough (AAO)
Oct 05 Gary Sanders (TMT Project Manager)
Oct 11 Uma Gorti (SETI)
Oct 17 James Truran (U. Chicago) ** cancelled **
Oct 18 Henrik Beuther (MPIA)
Oct 25 Gregory Sivakoff (U. Alberta)
Nov 01 Steven Allen (Stanford)
Nov 08 Ray Jayawardhana (U. Toronto) ** cancelled **
Nov 15 Pascale Jablonka (EPFL / Observatoire de Paris)
Nov 22 Gunther Hasinger (IfA)
Nov 29 Andrew Youdin (CfA)
Dec 06 Beth Willman (Haverford)
Dec 13 Chung-Pei Ma (UC Berkeley)
Spring 2011
Jan 05 Preethi Nair (U. Toronto/INAF)
Jan 17 Danilo Marchesini (Tufts)
Jan 26 Evgenya Shkolnik (DTM)
Feb 01 Charles Lawrence (JPL)
Feb 08 Cassie Fallscheer (UVic/NRC)
Feb 15 Rita Mann (NRC/DAO)
Feb 22 Ingrid Stairs (UBC)
Mar 08 Matt Walker (CfA)
Mar 15 Ata Sarajedini (U. Florida)
Mar 22 Sean M. Andrews (CfA)
Apr 05 John Dubinski (U. Toronto)
Apr 12 Eric Bell (U. Michigan)
Apr 19 Jon Willis (UVic)
Apr 26 John Carpenter (Caltech)
May 03 Bill McKinnon (St. Louis)
May 10 Richard de Grijs (UPeking/KIAA)
Fall 2010
Sep 14 Emily Schaller (U. Arizona)
Sep 20 Hendrik Hildebrandt (UBC)
Sep 21 Carol Lonsdale & Mark McKinnon (ALMA)
Sep 28 David Jewitt (UCLA)
Oct 05 Meridith Hughes (UC Berkeley)
Oct 07 Ricardo Munoz (Yale)
Oct 12 Mark Booth (Cambridge/DAO)
Oct 19 Jason Rowe (NASA Ames)
Oct 26 Andrew Benson (Caltech)
Nov 02 Lee Hartmann (U. Michigan)
Nov 09 Michele Cantiello (INAF)
Nov 16 No Seminar Schedule (CFHT Users Meeting in Taipei)
Nov 23 Guy Worthey (WSU)
Nov 30 Lisa Kewley (U. Hawaii)
Dec 07 Kristin Woodley (UBC)
Dec 09 James Di Francesco (NRC/DAO)
Dec 14 Sean Dougherty (NRC/DRAO)