I am an astronomer at the
Space Telescope Science Institute (STScI)
located in Baltimore, Maryland. I work on the formation of
planets and the origin of our own Solar System. One particularly
exciting question is how common the ingredients for life are
such as water) and whether they naturally evolve as part of
I also work as the James Webb Space Telescope Deputy Project Scientist at STScI. JWST is the scientific successor to the Hubble Space Telescope and the Spitzer Space Telescope. As the largest telescope ever put unto space, it is expected to spot the most distant galaxies in the Universe, dust and molecular gas around young stars in the process of making their own planetary systems, and, not least, to characterize the atmospheres of exoplanets.
I study the formation of planets in around young stars. The aim is to understand
how the Solar System formed, how extra-solar planets form and how the chemical composition
of their surfaces and atmospheres develop.
The Solar System is 4.6 billion years old, an ancient place, a
full third of the age of the Universe. It contains perhaps up to
20 objects - planets, moons and the new class of dwarf planets -
large enough that they can be considered "worlds". The Solar
System is also littered with rocks and snowballs, with sizes
ranging from mountains to boulders and even the tiny flecks that can
be seen as meteors when entering the Earth's atmosphere. While the
surface of the Earth is constantly being remodeled by erosion, volcanic
eruptions and the movement of tectonic plates, some of the rocks of the
Solar System have been orbiting the Sun virtually unchanged for billions of years.
They carry locked within them clues to how the Solar System formed. They tell a story of a nebula, hot with activity, bathed in ultraviolet radiation from an infant star. It was rich place, filled with water vapor and other more noxious gases, some of which must have contributed to the organic soup of Earths first oceans that gave rise to the first life forms. It also tells a violent story of the planets being formed from dust. Beginning with tiny smoke-like grains of minerals and carbon, growing and sticking together like snow flakes, ending with planetesimals up to a thousand miles across, some only to be destroyed in massive collisions. Those that survived formed the planets and moons we know today but with an amazing variety, from the icy geysers of Enceladus, the sulphuric hell of Io, the waters of Earth and the barren, rocky wasteland of Mercury. Such an incredible spectacle, how exciting it would be to have been around then, to witness the incredible formation of the Solar System, to understand the diversity and ultimately discover if the same story unfolds around many young stars - because if it does - then Earth is probably only one of many life-bearing worlds in the Universe.
Here you will find links to download software and a number of astronomical databases of infrared spectroscopy of disks and young stars. The data are free to use with appropriate reference to their original publication.
RADLite is a fast, easy-to-use line raytracer for axisymmetric geometries, developed as an add-on to the widely used RADMC continuum Monte Carlo code by Kees Dullemond. Written Fortran with an IDL wrapper, It is optimized for rapid rendering of the complex infrared spectra of molecular gas in protostars and protoplanetary disks, using input from the HITRAN database, but is inherently versatile. It includes IDL scripts for simulating line and line imaging observations. The code is described in greater detail in: Pontoppidan et al. 2009, ApJ.
Here you will find fully processed L- and M-band high resolution spectra of protoplanetary disks and young stellar objects.
The data were obtained during 2007-2009 as part of a large ESO program 179.C-0151
(The planet-forming zones of disks
around solar-mass stars) and 082.C-0432 (The distribution of water vapor in the
terrestrial zones of protoplanetary disks). In total, the database includes CRIRES 2-5 micron data collected during 30
nights of VLT time.
Team: The CRIRES protoplanetary disks program is a collaboration between investigators at various European and US institutions, including the California Institute of Technology, Leiden University, Max-Planck Institute for Extra-terrestrial Physics, UCLA, ESO and the Space Telescope Science Institute. Team members (original affiliations):
Ewine van Dishoeck (Leiden/MPE), Klaus Pontoppidan (STScI), Geoffrey Blake (Caltech), Joanna Brown (CfA), Gregory J. Herczeg (MPE), Rachel Smith (UCLA), Jeanette Bast (Leiden), Avi Mandell (NASA GSFC), Alain Smette (ESO), Hans Ulrich Kaufl (ESO), Wing-Fai Thi (Edinburgh/Grenoble), Bill Dent (Edinburgh), Isa Oliveira (Leiden)
This page contains fully reduced Spitzer-IRS high resolution spectra of disks from the Spitzer archive. The spectra are reduced using my pipeline CHIP (Caltech High-Res IRS Pipeline). It makes extensive use of standard star spectra to achieve the highest possible fidelity to uncover faint emission lines on top of bright continua. These spectra were used to characterize the spectra of water and other molecules from disks around young solar-type stars (e.g., Pontoppidan et al. )
This page contains fully reduced spectra, obtained as part of a large ESO VLT program (164.I-0605)
to observe ices toward (mainly low-mass) protostars in the 3-5 micron region with the near-infrared
ISAAC spectrometer on the VLT. The spectra contain the 3.1 micron water ice band and the 4.7 micron
CO ice band. In general, the former was observed using the low resolution mode of ISAAC, resulting
in resolving powers of R~600-1,200 (depending on slit width), while the latter used the medium
resolution mode, leading to resolving powers of R~5,000-10,000. The data were obtained
between 2000-2003. The Spitzer c2d spectroscopic sample was to a large degree based on the original ISAAC dataset.
Team: Ewine van Dishoeck, Emmanuel Dartois, Klaus Pontoppidan, Wing-Fai Thi, Louis d'Hendecourt, Adwin Boogert, Helen Fraser, Willem Schutte, Xander Tielens
Space Telescope Science Institute
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Baltimore, MD 21030
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