TODAY

The University of Western Ontario
DEPARTMENT OF PHYSICS AND ASTRONOMY

PHYSICS & ASTRONOMY COLLOQUIUM

Date:           Monday, 30^th April 2012
Time:          1:30 p.m.
Location:    Physics & Astronomy Seminar Room 22

Dr. Jean-Michel Désert
Harvard College Observatory
Harvard-Smithsonian Center for Astrophysics (CfA)

“From statistics to individual characterization of exoplanets”

ABSTRACT

The field of exoplanetary science has changed gear from the investigation of individual objects to statistical studies. In this talk, I discuss both the statistical approach and individual atmospheric characterization.

The Kepler mission has revealed an extraordinary and unprecedented number of small exoplanet candidates. However, a fundamental question remains about the overwhelmingly large sample of Kepler candidates: are these objects bona-fide planets? Importantly, we would like to know the false positive rate of this sample. I present a large program, obtained with the Spitzer Space Telescope, whose goals are to validate the planetary status of candidates and to estimate the Kepler false positive rate. Our results suggest that the Kepler false positive rate in this subset of candidates is low.

Answers to key questions about exoplanet science come not only from statistics, but also from individual characterization. Observations of their atmospheres are the only effective way at present to address the composition of exoplanets quantitatively and, by necessity, remotely. I present an ongoing comparative exoplanetology program to characterize planetary systems transiting nearby stars through the observation of their atmospheres. This project provides a powerful insight into the formation and evolution of planetary systems in general and enhances our understanding of our own solar system’s formation, one of the central questions in astrophysics. I also discuss the prospect of probing rocky exoplanet atmospheres orbiting in the habitable zone of their parent stars with future facilities.

Prof. Martin Houde has been named a co-Principal Investigator on the SOFIA (Stratospheric Observatory for Infrared Astronomy) science mission.

Martin will be involved in polarimetric measurement being taken with the HAWC (High-Resolution Airborne Wideband Camera) device, and he is the only Canadian scientist involved in the mission.

This paper has been making the rounds on my facebook feed.  It describes issues facing women in astronomy in Germany.

It’s rather interesting, not only because there are still difficulties that women have to face which men do not, but the paper also desribes how the women who responded to the survey got their jobs, so it contains some advice on how to pursue a career in astronomy as well.

Here’s a short video by Jorge Cham (the creator of PhD comics) explaining the Higg’s boson.

TODAY

Western University
DEPARTMENT OF PHYSICS AND ASTRONOMY

PHYSICS & ASTRONOMY COLLOQUIUM

Date:          Thursday, 26^th April 2012
Time:          1:30 p.m.
Location:    Physics & Astronomy Seminar Room 22

Dr. Shelley Wright
Department of Astronomy & Astrophysics
and Dunlap Institute of Astronomy & Astrophysics
University of Toronto

“Studying Galaxies in the Early Universe with Innovative Astronomical Instrumentation”

ABSTRACT

Studies of galaxies in the early universe (z > 1) have greatly benefited from recent advances in diffraction-limited techniques on 8-10m telescopes using adaptive optics (AO) and integral field spectroscopy. These innovative spectrographs have led to significant scientific achievements and are stimulating the design of future instrumentation. My talk will focus on development and use of the latest near-infrared instruments behind Keck Observatory’s AO system. I will present OSIRIS and Keck AO observations of spatially resolved optical emission lines (e.g., Halpha, and [N II]) from high-redshift (1 < z < 3) star forming galaxies. These results are part of an ongoing survey to study the dynamics, chemical abundances, and active galactic nuclei (AGN) in early galaxies. The high spatial resolution and 2D capability of an integral field spectrograph has allowed the discovery of some of the lowest luminosity AGN known at this epoch, and I will discuss their potential impact on high-redshift metallicity studies and galaxy formation. Lastly, I will discuss future instrumentation upgrades for OSIRIS and development of new instrumentation on extremely large telescopes (30m), which will offer extraordinary potential to probe the dynamics, assembly, and abundances of galaxies in the early universe.

  PHYSICS & ASTRONOMY Department

— Special Undergraduate LevelTalk —

Date:          Tuesday, 1^st May 2012
Time:          10:30 a.m.
Location:    Physics & Astronomy Seminar Room 22

Dr. Jean-Michel Désert
Harvard College Observatory
Harvard-Smithsonian Center for Astrophysics (CfA)

“Searching for signatures of life in the atmospheres of habitable exoplanets”

ABSTRACT

Biosignatures are the signs of life in the atmosphere of an exoplanet. On the Earth, the main biosignatures are oxygen, which is produced only in large quantities by plants and photosynthetic bacteria, and ozone, which is produced photochemically in the atmosphere from oxygen. Transiting extrasolar planets currently offer the best configuration in which to investigate their atmospheres and to search for remote signatures of life on these worlds. I will present the outstanding challenges, both technically and observationally, that we will need to overcome in order to probe rocky exoplanet atmospheres orbiting in the habitable zone of their parent stars, with the ultimate goal of detecting the planets’ biosignatures.

In a previous post, I promised a discussion about observing proposals, but Tyler beat me to it. So instead I want to shed some light on another aspect of the scientific life: the conference. I was thinking back on this, and amusingly, the first scientific conference I ever went to was the 1993 meeting of the Canadian Astronomical Society (CASCA), which was held right here at Western. I certainly never suspected then that I would end up back here as a prof.

There are different types of scientific conferences with different purposes. Scientific societies tend to have regularly-scheduled (N times per year, where 1/3<N<2) meetings. These provide opportunities for everyone in the field to get together: besides talks about science, they also often feature award presentations, trade shows, job interviews and meetings needed to run the society. We hosted the 2011 CASCA meeting here in London and have all mostly recovered from the experience. This type of meeting is often characterized as being more about networking than about science, though it can provide a good introduction to the field for new trainees.

Another type of meeting is the smaller meeting focused  on a particular topic. These meetings often have limited attendance and (at least in astronomy) are more likely to be on university campuses than at big conference centres. In this kind of meeting, the science talks and posters are the main focus. Networking also happens, of course, and can be more productive because all of the attendees have common interests.

I am going to 3 meetings this summer, which is more than usual. Meeting number 1 is the CASCA meeting in Calgary  which will feature an outing for the June 5 transit of Venus. Meeting number 2 is The Great Andromeda Galaxy, a specialized workshop on my favorite galaxy. And  meeting #3 is the 2012 Gemini Science meeting,  for which I somehow ended up being chair of the Science Organizing committee. I also wanted to go to a meeting called “Astronomy’s Discoveries and Physics Education”but it’s at the same time as meeting #2 above. Can’t be everywhere.

When I tell my non-scientist friends that I am going to a conference, they often ask “Are you going with anyone else from Western?” and “Will you have time to do any sight-seeing?” I try to explain that the purpose of going to a conference is not exactly to have a holiday with your friends. It really is all about meeting new colleagues (or old ones that you don’t see regularly) and talking science. Conferences can be intense and exhausting, particularly for introverts who find all the social interaction to be a bit much. But, in the best cases, conferences leave one energized and ready to go back home to work on all kinds of new ideas.

OK, I lied: sometimes conferences are related to holidays. My spouse is attending the 2012 annual meeting of the ISMRM and I am going along to Melbourne, Australia. Expect reports from the southern hemisphere next month.

It’s exam time so we need a little bit of levity. Here are the professor view and the student view of the “5 stages of grading”.

Don’t miss the excitement of the 2012 Gemini Science meeting. The abstract deadline is Friday, April 27.

http://gemini.edu/gsm12