Curriculum
Vitae of Pawel Artymowicz
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1994: Docent at Stockholm University, Sweden (the highest Swedish post-Ph.D. academic degree.)
1990: Ph.D. (with dist.) in astronomy from N. Copernicus Astronomical Center in Warsaw, Poland. (Thesis on ``Density waves in galaxies" written at STScI.)
1985: M.Sc. in astronomy from Warsaw University. (Thesis title ``Accretion of matter onto binary systems''.)
1993-1997: Research Associate (non-track Assist. Prof.) at Stockholm Observatory
1990-1993: Hubble
Fellow at Lick Observatory, University
of California at Santa Cruz, CA
(See also the Hubble
Fellows List)
1990-1993: Member of the Center for Star Formation Studies (Berkeley-NASA/Ames-Santa Cruz consortium)
1986-1990: Graduate Student Research
Assistant at Space Telescope Science Institute
(STScI);
Special Graduate Student at The Johns Hopkins
University, Baltimore, MD
1985-1986: Research Assistant at N. Copernicus Astronomical Center, Warsaw , Poland
1985: Summer Research Assistant at STScI, Baltimore, MD
1984-1985: Research Assistant, Warsaw University Observatory, Poland
1980-1985: Undergraduate study in Astronomy, Dept. of Physics, Warsaw University, Warsaw, Poland
Subject
editor (field: Extrasolar Systems) of journal Planetary
and Space Science (Elsevier, EGS);
Co-editor of IAU Symposium
No. 202 Planetary Systems in the Universe: Formation, Evolution,
and Detection.
@ Long programming experience [e.g., taught programming
on (8-bit!) ZX Sinclair Spectrum pre-PCs in early 1980s].
@ Written large CFD and Mte Carlo simulations from scratch
@ Fortran, C, some C++. Written a simple medical
database in Pascal in early 90s.
@ However, MUCH more day-to-day experience with FORTRAN than
C.
@ Familiar with many UNIX flavors on workstations (currently
Solaris)
@ Windows98 (not for programming)
@ Basic Perl , and tcsh or ksh programming
@ PVM (Parallel Virtual Machine),
MPI (Message Passing Interface)
@ Mathematica, basic MathCAD
@ IDL (Interactive Data Language, functionally similar to MatLab).
@ HTML
@ Designed and built a simple
mini-supercomputer
Hydra (planets.utsc.utoronto.ca/~pawel/hydra),
based on 8 Sun Ultra workstations and yielding up to ~5 GFLOP parallel
performance (1999). Hydra runs simultaneously MPI, PVM and
concurrent sequential tasks.
International Astronomical Union,
American Astronomical Society, Polish Astronomical Society,
Stockholm and Santa Cruz Flying Clubs.
2000: Invited by the Physics/Chemistry Nobel Commitee to nominate candidates for the Nobel Prize.
1994-2001: Research grants from NFR (Swedish Natural Science Research Council)
1999-2001: Postdoctoral grant from NFR for Taku Takeuchi.
1997: Research grant for the project "Physics of Binary Star Formation" from the Crafoord Foundation (awarded by the Royal Swedish Academy of Sciences in connection with the 1997 Crafoord Prize awarded to F. Hoyle and E. Salpeter.)
1997-2000: The STINT (Swedish Foundation for International Cooperation in Research and Higher Education) grant for scientific exchange program between the Astronomy Departments of Stockholm University and University of California, Santa Cruz, US. (One of the 2 Responsible Scientists for that program.)
1996: Letter of Commendation from the Editorial Board of Icarus
1997-1999: Co-investigator, NASA Origins Program grant (with Steve Lubow, STScI, and Jim Pringle, Cambridge U.)
1996-1997: The STINT grant for a Visiting Scientist/Scholar - Eric Pantin. Also, postdoctoral visiting fellowship grant for the same researcher in 1997 from NFR.
1990-1993: Hubble Fellowship , awarded by the Space Telescope Science Institute, NASA grant HF-1000.01-90A. (See also Hubble Fellows List.)
1984: Award for Young Astronomers, from the Polish Astronomical Society.
My collaborators, in turn, visited
me in Stockholm:
P.-O. Lagage, E. Pantin, D. Backman,
S. Lubow, W. Kley, M. Clampin, S. Heap, P. Bodenheimer
In 1995 alone I obtained Visiting Fellowships from: the Max-Planck Society's group in Jena (FRG), Space Telescope Science Inst. in Baltimore (MD), Princeton University (NJ), and University of California, Santa Cruz (CA), and spent 1 month in each.
I attended half a dozen other international conferences, presenting invited contributed talks, and given numerous seminars across USA and Europe.
I served on Scientific
Organizing Committees for:
1999 VLT Inauguration Symposium;
1999 meeting of the Div. of Planet.
Sci. of AAS in Padova, Italy;
IAU Symposium 200 in Potsdam, Germany
(2000);
Joint Discussion No. 4 and the
IAU Symposium 202 at the General
Assembly of IAU (2000), and the future
2001 meeting of JENAM (Joint Euro.
Astron. Meeting) in Garching, Germany.
2002 Nanjing (China) symposium
Astrophysical
tides: the effects in the solar and exoplanetary systems,
2002 Goddard SFC/Washington D.C.
conference Scientific Frontiers in Research on Extrasolar Planets.
I served as Convener of a session on Extra-solar planets and planet formation at the 2000 General Assembly of European Geophys. Union in Nice, FR.
I refereed papers submitted to international astronomical journals (ApJ, A&A, AJ, MNRAS, Icarus, Science, Pl. Space Sci, Ap. Sp. Sci., Earth Pl. Sp., PASJ), and reviewed several grant proposals a year for U.S. NSF and NASA, as well as KBN (Polish equivalent of NSF).
I served on eight Ph.D. examination committees at the Universities of Stockholm, Uppsala, Gothenburg, Paris, Grenoble, Torun, and Monash Universities, and one habilitation committee in Grenoble.
I am a Coordinator (PI) of the European Union INTAS program `Perturbers and density waves in accretion disks: the origin of cyclic variability of the pre-main-sequence stars', involving 14 participants from 4 west-European centers, and 20 participants form 4 institutes from CIS (RU, UA, UZ).
I am one of the two managing scientists of the 4-yr STINT-financed, Stockholm Observatory-Lick Observatory/UCSC scientific exchange program (annual budget up to $50k).
Within the past 3 years I established a new research group at our Observatory, studying theoretically the origins of planetary systems. Besides myself, it includes: postdoctoral fellow Taku Takeuchi, beginning graduate students Anna Grigorieva and Adam Peplinski, and a finishing undergraduate student Anders Jeneskog. My colleagues focus on the characterization of dust in Beta Pictoris disk based on the new HST/STIS observations, parallel computer simulation of the origin of Beta Pic's disk asymmetries, the hydrodynamical modeling of gas disks, and dust migration in disks.
Our work was recently been evaluated
as "excellent and a clear highlight of the Observatory's program" by an
international Evaluation
Commitee for Swedish Astronomy and Astrophysics (2000). The committee
recommended our project toNFR (now: Science Board) for continued support/expansion.
I enjoy giving several popular talks per year. I also have a frequently visited (unfortunately a bit outdated!) web presentation, averaging more then one new viewer per hour (>10^4 page req./mo.). It is accessible from yahoo.com page by clicking on Astronomy, Extrasolar Planets, and then Planetary systems and their changing theories.
My work was selected for press release at the AAS convention in Pittsburgh, PA (1995), and discussed by J. Glanz in Science editorials (in 1995 and 1997), by G. Marcy and P. Butler in the Sky & Telescope (March 1998), in Science News (Aug. 1998) by Ron Cowen, and in Forskning och Framsteg (2000) by Jens Ergon. The largest Polish and Swedish dailies Gazeta Wyborcza and Dagens Nyheter, as well as the British Economist, published in 1998-2000 interviews and stories on extrasolar planets with my input. In 2000 I appeared on the Swedish TV science program NOVA.
Anders Jeneskog from Uppsala University,
currently writing his B.Sc. thesis under my supervision at Stockholm U.,
first contacted me after seeing a special 1998 issue of Scientific American
on exoplanets with references to my work. The fraction of those students
most recently offered the departamental graduate assistantships who joined
our theory group is high (more than 50%). Thus, the attractiveness of the
subject plus some publicity greatly helped recruit young researchers.
12. Impact and Competitiveness
I am not a prolific writer, but I write interesting papers, i.e. papers with high professional impact measured by the total number of citations, or citations per paper. Somewhat surprizingly then, I seem to have been the most cited "young astronomer" in Sweden recently (in Sweden you're young until 40). I do have a few "classic" papers with a high, sustained rate of citations (~10/yr).
In 2000 my group's work was highly rated by an international committee reviewing the Swedish Astronomy and Astrophysics (see the relevant part here).
In addition to job offers I accepted, I was also selected for a 2-yr professorship at the University of Rochester, NY, and a tenure-track professorship at Vanderbilt University, Nashville, TN. I have been ranked first among: ~100 applicants for postdoctoral position at the University of Maryland (1993), 70 applicants for the research associate position (1993), 300 applicants for the faculty job at Vanderbilt (1996), and 40 applicants for my present position, NFRs tenure-track Asst Prof. (aka. Senior Researcher) (1997).
13. Some of the Things I Enjoy
Flying
: Buzzing the Golden Gate bridge and the Puu-Oo vent of Kilauea, crossing
the Baltic solo in a single-engine Piper Arrow and Cessna 150,
discussing artificial horizon and VOR radio navigation with my 7-yr old
son. Mountain biking on lake Tahoe trails (Great Plume), surfing in cyberspace,
snorkeling on Big Island, boogie-boarding in Santa Cruz, skating in the
frozen Stockholm archipelago, skiing in the Arapahoe Basin or Sierra. Hiking
in the Black Canyon of the Gunnison, or the barrancos on Tenerife. Volcanic
rocks and fossils. Conference-related tourism, art museums (esp. `Kandinsky,
Klee, Miro, Ernst). Discovering
fractals
.
Stock market. Very amateur chess.
14. Previous
and Current Research
(Bracketed numbers refer to the List of Publications, enclosed below)
14.1.Pre-doctoral work and the Ph.D. thesis
14.1.1.From particle physics to star and planet formation
As a beginning undergraduate I was seriously interested in elementary particle physics; I spent the summer of 1982 at the e+e- collider DESY (Deutsches Elektronen-Synchrotron) in Hamburg, FRG. I also wrote a simple paper on quarkonium [3]. But I also studied double star formation, and in 1983 reported the results at the NATO Adv. Study Institute in Cambridge (cf. [1],[2]). This was the core of my M.Sc thesis. (A decade later, in his Ph.D. thesis, Matthew Bate recomputed this problem using better techniques and obtained similar results.) After graduation in 1985 I got interested in disks and solar system formation. I used the Jacobi constant to analyze in detail the growth of a planetary embryo in the planetesimal disk, and found the effective width of the `feeding zone' and the planetary mass at which its early runaway growth stage ends due to the non-linear increase of the Hill sphere radius [4] (a.k.a. "isolation mass").
14.1.2.Getting to know beta Pictoris
I worked at STScI with Francesco Paresce and Chris Burrows on image processing and theoretical interpretation of the observations of beta Pic. Our analysis [6] revealed new information on its dusty disk and became a standard reference in the field. We realized that the thickness of the disk increases with radius. Using maximum entropy technique, we have found (in contrast to some gurus in that subject) that the beta Pic grains are highly reflective, which indicated either a slightly contaminated ice or semi-transparent silicates such as Mg-rich olivine (detected 4 years later). I have also studied the dynamics of beta Pic grains for a wide range of realistic grain compositions [5], and concluded that radiation pressure removes sub-micron sized grains, which explains the disk's nearly grey scattering. In [7],[8] and [10] we clarified the nature and evolutionary status of beta Pic. We found evidence that beta Pic system is a nearby extrasolar analog of the early solar system, in particular that it is more evolutionary advanced than a protoplanetary nebula, and that its dust is being rapidly destroyed and replenished. Obvious as it may appear now, this was a significant step at the time when others were thinking about "snowballing" of icy particles and the Poynting-Robertson drag.
Under the supervision of Steve Lubow and Wojciech Dziembowski, I wrote at STScI and defended in Warsaw a thesis on the dynamics of ultraharmonic resonances in galactic disks ([9],[11],[13]). At these resonances, located between the Lindblad and the corotational resonances, non-linear effects lead to the excitation of 4-armed features (inter-arms) and a strong local damping of the main 2-armed density wave. Both effects have been detected (e.g., Elmegreen, Elmegreen & Seiden, 1989, ApJ, 343, 602). Ultraharmonic resonances may play a key role in the stability of the spiral structure in some spirals, by damping the growth of global m=2 modes. While working on the paper [13] with Steve Lubow I had a chance to gain a deep insight into the Lindblad resonances (cf. below).
With Cathy Clarke, Steve Lubow, and Jim Pringle, I have co-discovered the phenomenon of rapid growth of (initially small) eccentricity of a binary system embedded in an extended protostellar (or other) gas disk ([12],[14]). The forming binary star can undergo a significant orbital evolution before the disk dispersal. This may explain some features in the distribution of orbital elements (size and eccentricity) of the pre-main-sequence (PMS) and main-sequence binaries (cf. Mathieu, R.D., 1994, ARA&A, 32, 645) [12],[15].
In collaboration with Lubow I have studied the resonant and tidal interactions of a binary with a disk. This theory predicts the creation of a gap around a binary, with the size depending on the binary separation, mass ratio and (the previously neglected) eccentricity [22]. If `there is nothing more practical than a good theory', then this one might be an example: observers have since used the predicted gap sizes in many situations, and they seem to `work well' (are consistent with existing data, and provide guidance for new observations).
We tackled the problems of mass accretion through the circumbinary gap, and the long-term evolution of PMS binaries ([27],[28],[30],[35],[36]). From the SPH numerical simulations, and my as yet only partially published grid-based PPM models, it follows that gas flows through gaps should indeed be a very widespread phenomenon. Their specific time variability (in eccentric binary systems) can be used as a fine diagnostic tool in the study of the orbital parameters of the binary (which may be difficult to obtain otherwise, because the binary may be unresolved or have a long-period). The theory has been successfully applied to interpret the observations of several prominent PMS binary systems such as GG Tau, DQ Tau, AK Sco and others. The first system is a long-period binary with poorly known, but significant, historic variability, and the newly observed presence of gas streamers (again, not yet well imaged). Periodic flares of the second system, a short-period spectroscopic, classical T Tauri binary DQ Tau, are consistent photometrically and pectroscopically with our predictions. Additional evidence for gas streaming through the gap was found in the IR spectral energy distributions of classical T Tau stars, accretion luminosity of the IR companions to PMS stars, etc.
For the review of the theoretical and observational aspects of the disk-binary interaction please see our chapter in the `Protostars and Planets IV' book [49] , and [55]. Aside from the PMS systems, our work may also be relevant to binary supermassive black holes in AGNs [41], and to some post-Asymptotic Giant Branch stars [27].
14.2.2. From Lindblad resonances to planetesimals and super-planets
In the formation of planets, three characters play a crucial role: a, m, and e. My work was directed towards calculating the early evolution of these three orbital elements.
I developed a post-Goldreich-Tremaine'an, generalized theory of Lindblad resonances [16]. The non-WKB nature of the theory allowed the description of the so-called torque cutoff phenomenon at high azimuthal harmonic numbers m. I applied it to the interaction of, e.g., planetesimals in the solar nebula [17]. Too small to open a gap, such bodies suffer a rapid decay of the orbital eccentricity (faster than due to gas drag or nebular lifetime). The generalized resonance theory has also served as a basis for the recent study of a crucial process of orbital migration (type I) of planetesimals and protoplanets by Bill Ward (1997, ApJ, 428, L21; see also Ward and Hahn's chapter in Protostars and Planets IV book, 2000). Migration of some sort is thought be responsible for the existence of the so-called `hot Jupiters' or 51 Peg-type giant planets on tight circumstellar orbits.
The process of gas streaming through disk gaps (similar to that mentioned above but not controlled by the orbital eccentricity) is highly relevant to the origin of `superplanets' (massive extrasolar planets, usually on eccentric orbits). We have proposed that such planets form via continued accretion from the standard protoplanetary disk onto Jupiter-sized planets ([27],[38],[40],[42]-[44]). (In contrast, the standard Lin-Papaloizou theory predicted that accretion stops at about 1 Jupiter mass, when the disk gap opens). Other theoretical groups have confirmed the presence and magnitude of the flows through the gap, using independent hydrocodes (Kley 1999, in MNRAS; Bryden et al. 1999, in ApJ).
As to the origin of the eccentricities of the planets, several possibilities exist for exciting e (as described, for instance, in [38],[40],[42]), such as: stellar and mutual planetary perturbations, disk-planet interaction and disk instabilities. My work concerned the disk-planet scenario, as the only one naturally explaining a (weak) observed correlation of planet mass with eccentricity and, what is perhaps even more important, the only one capable of reducing the eccentricities excited by any of the above-mentioned interactions in solar-like low-eccentricity systems. (Levison, Lissauer, and Duncan 1999, in their down-top accumulation models of the outer solar system, vividly illustrated the need for an efficient damping mechanism.) In 1992 I have noted in [15] that, for a typical disk representing a minimum mass solar nebula, there is a crossover mass (equal roughly to 10 Jupiter masses for alpha-disks with alpha ~ 10^(-2); less for less viscous disks), below which the disk-planet interaction damps e, and above which e increases. The jury is still out on which of the eccentricity driving mechanisms is dominant under typical circumstances. There is increasing evidence that the disk-planet and the N-body interactions may indeed both be required for producing the observed diversity of orbital parameters of solar and extrasolar planets [51].
14.2.3. Active galactic nuclei
With Doug Lin (UCSC) and Joe Wampler
(ESO, Garching) we have sought a better theoretical understanding of active
galactic nuclei, in particular of the interaction of field stars with disks
around massive black holes in quasars and AGNs. We have calculated
([18], [19]) the trapping rate of stars from the host galaxy's nucleus
in gaseous disks or cloud assemblages. The physics of trapping involves
the usual supersonic gas drag and the resonant excitation of bending and
density waves in the gas. I have formulated a generalized theory
of bending and density wave generation in
astrophysical disks [20], quantifying
the trapping time. The trapped stars provide seeds for rapid accretion
of gas. This leads to the emergence of short-lived massive main sequence
stars, which eventually contaminate the disk with heavy elements.
The rate of metallicity enrichment by seeded star formation is remarkably
model-independent, and can explain super-solar metallicities in quasars
and AGNs. The stellar-mass compact remnants of supernovae can be
re-trapped, grow, and exchange angular momentum with the gaseous disk,
which may give rise to effective viscosity parameter alpha
of order unity [21].
I have recently reviewed the evolution of supermassive binary black holes in merging galaxies [41]. This is somewhat of an elusive topic (observations still being few and far between) with parallels to the physics of binary star interaction with disks. Interaction with the gas disk can drive the evolution of a massive black hole pair, tightening it sufficiently for an eventual gravitational-wave assisted merger. During the tightening, interesting activity patterns may be produced (quasi-periodic variability of sources, like in the blazar OJ 287; wiggly, spiral-like jets of radio galaxies and AGNs, double emission lines).
14.2.4. Vega-type systems & Beta Pictoris
I have worked on diverse aspects of the Vega-type systems and their most prominent member beta Pic [23],[24],[29],[31] -[34],[36],[37],[39]). The topics range from the physics and mineralogy of dust, evolutionary time scales for the observable disk, and disk polarization, to observational constraints on gaseous refractory species, lower limit on dust:gas ratio, etc. I have participated as co-investigator with C. Burrows, M. Clampin, and E. Pantin and others, in observational programs using HST and ESO telescopes (not all of the data has been analyzed yet). I collaborate with Sally Heap's group at GSFC on the STIS imaging of beta Pictoris [56].
During a visit to Stockholm by Sally Heap (GSFC) and Eric Pantin (Saclay, FR) we have analyzed the new STIS/HST images of Beta Pictoris and fitted a refreshingly simple, non-power-law parametric model of the dust distribution. (This work is still unpublished.)
Preparing a chapter for Annual Review [33], I was fascinated by the close relation between Vega-type systems and planetary systems, and the numerous open questions about individual systems, e.g., the origin of asymmetries and the warp in the beta Pic disk. More generally, our paper with Clampin [36] considered the nature vs. nurture question in the Vega phenomenon (presence of IR excess, plus other requirements [50]). We have found serious problems with the two recent "sandblasting" theories invoking the influence of ISM (and therefore `nurture'). We found that the internal evolution (`nature') is responsible for dusty disks around ~20% of normal stars.
I developed some new `rules of conduct' for extrasolar dust disks. I proposed the concept of radiation-driven dust avalanches in gas-poor disks, a process which becomes (exponentially) important and self-limiting for dust coverage factors approaching that of beta Pic. It implies that there should be no gas-free disks with much more dust coverage than beta Pic, and that there should be a dichotomy in the distribution of dust covering factors among the IR excess systems. In [32], I was able to identify empirically two distinct subgroups of Vega-type systems (one containing the gas-rich, young, and very dusty systems, and the other of more typical, gas-poor, optically thin beta Pic analogs).
Recently, with Taku Takeuchi, we
have analyzed the physical processing of dust grains in the somewhat younger,
optically thin disks, with a modest amount of gas (the so-called
old PMS systems or `transitional', disks such as HR 4796A and
HD 141596; [51]-[53]). We have found a rapid
14.2.5. N-body dynamics of planetary systems
With Doug Lin and Resemary Mardling, I study the dynamics of upsilon Andromedae, the first multiplanetary system among the candidates discovered in radial velocity surveys (Butler, Marcy, Fisher et al.\ 1999). I performed extensive direct N-body simulations of the two outermost planets in a timespan of 2 Gyr (longer than any other existing N-body calculation), with the innermost planet averaged into the Gauss ring around the star. We found [54] that the inner planet is probably not important for the long-term evolution, and now are working to confirm this conclusion in simulations allowing the inner planet to evolve secularly. In sharp contrast to some earlier papers on that subject, we find large, acceptable, parameter space regions guaranteeing long-term stability of upsilon And. Our work raises questions about the origin of one highly unusual property of the system: the masses and orbital eccentricities of the three planets all increase with semi-major axis. Such a correlation cannot be due to the N-body interaction of the present planets. We are exploring other possibilities.
14.2.6. Books on the Astrophysics of the Solar Systems
I have written a 540-page book Astrophysics
of Solar Systems, dealing with solar and extrasolar planetary systems
[26]. It appeared in 1995 (in Polish) as the closing volume in a
series of three upper-undergraduate and/or graduate, modern astrophysics
textbooks. It is used in that capacity at the Warsaw U.; it
has received favorable reviews.
With Peter Bodenheimer (UCSC) we
are currently starting to write for Springer-Verlag a somewhat similar
new book [57], this time emphasizing strongly the extrasolar planetary
systems.
Abstracts (e.g., BAAS abstracts), are omitted. Papers in preparation or submitted but not yet printed are marked [red].