Homepage of René Oudmaijer
Hello, I am a Professor in Observational Astronomy here at the School of Physics and Astronomy in Leeds. Like virtually all academics, I have two jobs. Much of my time I conduct scientific research and during the rest of the time I tell students about it, and more.
My research mostly concerns the formation of stars and how they die. This may seem a bit contradictory, but as a matter of fact, in many cases, old and young stars look very much alike. This is because stars are often surrounded by dusty and gaseous material. In the case of young stars, it is from this material that the stars and their planets form, for the older ones, it is the material they eject in their last puffs. In either case, the properties of the circumstellar material reveal very important information about the process of star formation and stellar death. In the intervening, much much, longer time, the stars are mostly free from such circumstellar material. Sometimes it is even hard to tell whether a star is old or young. It may therefore not come as a surprise that these objects can be studied observationally with the same methods. That is what I do in much of my work. In particular, I try to probe ever closer to the star using a variety of cutting edge methods to reach the finest resolutions possible.
If you want to know a bit more about the background of my research, I wrote a small article based on the public lectures I have given on Star Formation. You can find it here. Other short articles meant for general reading are based on some of the methods I use. They are published in the "Astronomy and Geophysics", the glossy magazine published by the Royal Astronomical Society. Most recently, I wrote an article on Optical Interferometry (click on the link to access the the paper), while a few years ago, I wrote about Spectropolarimetry and its many applications. Try pronouncing that word! Further, more in depth, papers which cover my work are a review on disks around stars which was published as a chapter in a book. The link to the abstract and PDF file is here. Another overview paper is on massive, evolved stars, so-called post-Red Supergiants. You can find it at this location. My full publication list can be accessed here, and below is a small breakdown on what I've been up to recently.
Representative examples of the work I have been doing over the last few years can be found in a series of short papers (so-called "Letters to the Editor") that I published recently. For example, there is a paper on spectro-astrometry, in which we manage to determine the kinematical signature of a rotating disk (published in MNRAS, 2012); on 20 micron diffraction limited imaging, (A&A, 2011), where we resolve the shells around an evolved star, which ended up being baptized the "Fried Egg Nebula”; a paper on one of our main results of the RMS survey, where we determine the luminosity function of Massive Young Stellar Objects and HII regions (2011 ApJ); and work on interferometry, in which we resolve the envelope of a Massive Young Star (2011, A&A).
Many of these Letters and other papers are the result of my collaboration with our post-docs who worked here (James Urquhart, Willem-Jan de Wit, Ben Davies, Hugh Wheelwright and currently Koji Murakawa), and with Melvin Hoare and Stuart Lumsden who are also in the Astrophysics Group in Leeds.
Studying young and old stars have also featured a lot in my work as a PhD supervisor:
In a study we find that the binarity of the so-called Herbig Ae/Be stars, intermediate mass pre-main sequence stars, is very high. This result was based on spectro-astrometry and the paper, first-authored by Deborah Baines who obtained her PhD in 2004 and is now working at Villa-Franca, ESAC, Spain, is here.
Ben Davies (PhD in 2006, currently an RAS Fellow at the IoA in Cambridge) did some ground-breaking work on the Luminous Blue Variables. He found that their polarization properties are due to clumping, while he also found, with AO assisted integral-field spectroscopy that the inner parts of the wind from a famous post-red Supergiant (IRC +10420) is axisymmetric. Here are links to his papers.
Andrew Clarke defended his PhD thesis in 2007 and worked predominately on the RMS project. This is an ambitious Leeds-led (Melvin Hoare, Stuart Lumsden and myself) survey designed to retrieve all Massive Young Stellar Objects in the Galaxy. This has now completed, and Andrew was in charge of near-infrared follow-on spectroscopy. An important side-result in his large database of spectra was his discovery that the Duck-nebula could in fact be a long-sought transition object between these MYSOs and the further evolved HII regions.
Hugh Wheelwright (PhD in 2010, now at the Max Planck Institut in Bonn), published a paper, where he disentangled the spectra of both components in an otherwise unresolved binary and solves the problem of the peculiar Halpha emission from the magnetic object Beta Cephei, the prototype of the Beta Ceph stars. The emission comes from the companion Be star! Recently, he managed to top that feat by splitting the spectra of a sample of Herbig Ae/Be binary stars and determined their mass ratio. , while even more recently he found that the disks around the primary stars are aligned with the binary orbital planes, lending much support to disk fragmentation as a means to form massive stars.
Currently John Fairlamb and John Ilee work with me on spectroscopy of young stars.
We are always on the look-out for good PhD students and if you want to know more about PhD possibilities at Leeds, check here, or just drop me a line at roud @ ast.leeds.ac.uk(don't forget to remove the spaces around @).
My work with Master students (MSc and MPhys) has also proved productive. For example, Mitesh Patel (PhD at Imperial College) and Joe Mottram (now at Leiden) published some neat work on polarization properties of post-Red Supergiants and the difference between Herbig Ae and Herbig Be stars which appears to indicate that the transition between different star forming mechanisms may appear at higher masses than previously thought. Andrew Parr did some very nice AO-assisted imaging work to determine the binary fraction of Be and B stars.
This brings me to my other teaching here at Leeds. For many years I taught PHYS2051, Cosmology, to the second year students and PHYS3280, Star and Planet Formation in the third year. Later I taught PHYS1170, The physics of Stars and Planets to our first year students, and currently I teach PHYS2150, Stellar Structure and Evolution in the second year and the electromagnetism part of the first year PHYS1200, Physics 1 supermodule. Information related to these modules, including previous exams, problem sheets etc. can be found on the (internal access only) BlackBoard website.
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