Research Homepage of Christian D. Ott
I am a computational/theoretical astrophysicist in TAPIR at Caltech working at
the interface of numerical relativity, nuclear/neutrino astrophysics,
and gravitational-wave physics. My current primary research interest
is to find ways to blow up massive stars, that is, make core-collapse
supernovae and gamma-ray bursts and their compact remnants, black
holes and neutron stars. This work is carried out as part of the Simulating eXtreme Spacetimes
(SXS) collaboration and we also work closely with the Einstein Toolkit team.
Another line of my research is
concerned with the observation and interpretation of gravitational
waves using the LIGO
interferometers and I am a member of the LIGO Scientific Collaboration.
I am presently an Alfred P. Sloan Research Fellow and am leading
an NSF CAREER project in Gravitational Physics.
I received my PhD in 2007 at the Max Planck Institute for Gravitational
Physics under Bernard Schutz's and Ed Seidel's supervision and then
was a Joint Institute for Nuclear Astrophysics postdoctoral fellow with
Adam Burrows at The University of Arizona before joining Caltech.
More details can be found in my CV.
Follow me on Twitter:
Read my blog: Blowing Up Stars
Members of the computational relativistic astrophysics / numerical relativity group at TAPIR:
|Undergrads||Hannah Klion, Iryna Butsky, David Vartanyan, Lauren Gilbert, Anthony Alvarez (working with Scheel)|
|Grad students: ||Sarah Gossan, Hannalore Gerling-Dunsmore (joining fall 2014), Maria Okounkova (joining fall 2014), Sherwood Richers (DOE CSGF), Jonas Lippuner, Joshua Blumenkopf, Matt Giesler (working with Scheel), Kevin Barkett (working with Scheel), Jon Blackman (working with Szilagyi)|
|Postdocs||Ernazar Abdikamalov, Drew Clausen (DuBridge Prize Fellow) Roland Haas, Daniel Hemberger, Philipp Mösta, Viktoriya Morozova, Tony Piro, David Radice (Sherman Fairchild Prize Fellow), Christian Reisswig (Einstein Fellow), Luke Roberts (Einstein Fellow), Nick Taylor|
|Senior Researchers||Mark Scheel, Béla Szilágyi|
|Visitors||Jocelyn Read, Geoffrey Lovelace, Uli Sperhake and Steve Drasco (visualization)|
|Admins:||JoAnn Boyd, Nannette Pettis (grant manager)|
The SXS collaboration is supported by NSF, DOE, The Alfred P. Sloan Foundation, and by the Sherman Fairchild Foundation.
|Senior Thesis:||If you are a Caltech undergrad and interested in doing a senior thesis in Ay or Ph, please come see me! I am happy to advise senior thesis work and have a number of interesting projects available.
|Prospective Summer Undergrads:||We work with the LIGO REU program. Please see the projects and application procedures listed there. Caltech undergrads should contact me directly about SURF possibilities.||
|Prospective Grad Students:||My group has a long list of projects suitable for starting grad students. If you are
interested in the stuff we do and would like to apply to the Caltech
Astrophysics and/or the Caltech Physics graduate programs, feel free
to contact me to discuss potential research projects. Please do not
send me your application materials -- these should go to the graduate
program. The admission decision will be made by the graduate admission
My group is actively trying to increase the representation of women
and minorities in theoretical physics and astrophysics. We thus especially
encourage women and minorities to apply.
New Stuff (in quasi-chronological order)
- 2014/03/05 Magnetorotational Core-Collapse Supernovae in 3D: Mösta et al. 2014, arXiv:1403.1230
What drives hypernovae, extreme supernova explosions that have
many times the explosion energy of a garden-variety supernova from a
Detailed simulations show that the standard mechanism for
core-collapse supernovae -- the neutrino mechanism -- seems to lack
the efficiency to drive such powerful explosions.
A possibly more powerful alternative could be
the magnetorotational mechanism. In this scenario, rapid
rotation (a proto-neutron star with a millisecond spin period) in
combination with a very strong toroidal magnetic field
(1015-1016 G) are expected to push out
energetic bipolar outflows along the axis of rotation.
Our team has just completed the first set of full 3D,
dynamical-spacetime GR-magnetohydrodynamic simulations of
magnetorotational core-collapse supernovae. This work was led by postdoc
Richers (DOE Computational Science Graduate Fellow) made important
In collaboration with other team members, Philipp and
Sherwood showed that the configuration that leads to strong jets in
axisymmetry is unstable in 3D to an MHD kink instability,
leading to a spiral deformation of the outflow. The volume rendering
the left shows the entropy distribution at some 160 milliseconds after
core bounce. Red indicates high entropy (about >10
kB/baryon), blue low entropy (a few
kB/baryon). The vertical axis is the vertical and the scale
is 1600 km. Instead of a clean jet, two huge lobes develop that move
out secularly as the proto-neutron star pushes spiral streams of out
hot, highly magnetized plasma into polar regions.
Interested in learning more? Check out
our paper and the movies that
go along with it stellarcollapse.org/3dgrmhd.
The simulations used of the open-source Einstein Toolkit and additional source code and input parameters needed to reproduce our simulations can be found at stellarcollapse.org/3dgrmhd.
- 2013/07/27 Caltech Gravitational Wave Astrophysics School 2013
A week of exciting lectures, two parties and a field trip to Mt. Wilson Observatory (see group picture in front of the 100-inch Hooker telescope!) is over. We'll do it again in two years!
- 2013/07/01 Congratulations Dr. Jeff Kaplan!
PhD offspring #2! Jeff will join the US STEM workforce in finance.
- 2013/02/12 Announcing the Caltech Gravitational Wave Astrophysics School (CGWAS 2013)
CGWAS 2013 is a summer school for senior undergraduates and graduate students interested in the astrophysics of gravitational wave sources, gravitational wave astronomy, and multi-messenger follow-up observations of gravitational wave detections in the Advanced LIGO/Virgo era.
CGWAS will take place July 22-26, 2013 on the Caltech campus.
Attendance is free, but limited. Support for accomodation
in Caltech campus housing is available. Apply at http://www.cgwas.org.
CGWAS is supported by my NSF CAREER award and is part of my
CAREER education/outreach program.
- 2012/10/24 Our first full 3D Core-Collapse Supernova Paper is out!
General-Relativistic Simulations of Three-Dimensional Core-Collapse Supernovae
We ran four full 3D full GR (time-evolving Einstein's field equations)
simulations of a 27-solar-mass progenitor star that was shown by Müller
et al. to be especially susceptible to the Standing Accretion
Shock Instability (SASI) in axisymmetry. |
Our goal was to see (1)
if the SASI develops in a similar way even in 3D (where the dynamics
is not forced to be symmetric about one of the axes) and (2) how the
behavior of the SASI changes when the strength of neutrino heating is
We found that the SASI, while present in 3D, never reaches the
strength seen in the 2D simulations of Müller
et al. In our simulations, neutrino-driven convection was seeded early on
and grew to become the dominant instability. We also found that as the
explosion developed, the shock front became strongly distorted, showing large
scale asymmetry and many small-scale protrusions, as can be seen in the volume rendering
of the specific entropy distribution shown on the right.
- 2012/07/01 As of today, our group member Christian Reisswig is a NASA Einstein Fellow. Christian will continue to work with us at Caltech
for the next three years.
- 2012/06/26 I was invited to participate in the NSF
CyberBridges workshop (funded by the Office of Cyberinfrastructure) in
Arlington, VA, June 25/26, 2012. This was a great workshop bringing
together (1) NSF CAREER recipients in computational science from a broad
range of backgrounds, (2) international leaders in computational science, and
(3) NSF program directors. I learned a lot and met many interesting people.
I also learned about figshare and uploaded
the poster that I presented.
- 2012/06/09 Invited plenary talk at Neutrino 2012 in Kyoto -- my biggest audience yet: 600 particle (astro-)physicists! A copy of my presentation is available for download.
- 2012/05/22 The Caltech Supernova Group produces its first PhD: Congratulations Dr. Evan O'Connor!
Evan will join the Canadian Institute for Theoretical Astrophysics (CITA) at the University of Toronto as a postdoctoral fellow this fall.
2012/05/11 The American Physical Society Topical Group in Gravitation (GGR) executive committee election results are out: I am now a Member at Large of GGR and will serve
on the executive committee for the next three years!
2012/02/15 I was named a 2012-2014 Alfred P. Sloan Research Fellow.
2012/01/19 My postdoc Christian Reisswig has been announced of one of the 2012 Einstein Fellowship recipients!! Congratulations, Christian!
2012/01/10 My NSF CAREER proposal in Gravitational Physics will be funded!
2011/06/20-24 Microphysics in Computational Relativistic
Astrophysics 2011 (MICRA 2011) workshop at the Perimeter Institute,
Waterloo, Ontario, Canada. This is the second MICRA (the first one was in 2009 at the Niels Bohr Institute in Copenhagen, Denmark) that I co-organized and I think it was another great success. Slides are available at micra2011.org.
2010/07/06 -- invited talk
at GR19 in Mexico City on some brand
new results on the formation of stellar mass black holes. Slides are available
I was on TV!!! I participated in episode 2 Black Holes of the
Discovery Science Channel show Through the Wormhole (hosted by
Morgan Freeman!). Check out the show on YouTube!
Some Current Projects and Collaborations
My team at Caltech, which is part of the Simualting eXtreme Spacetimes
collaboration, is working on full 3D simulations of core-collapse
supernovae with the ultimate goal of connecting precollapse conditions
to the various possible outcomes of stellar collapse and their multi-messenger
(photons, neutrinos, gravitational waves) signatures.
I am a member of the Einstein Toolkit
that aims to provide well tested and documented open-source
simulation codes to the numerical relativity and astrophysics modeling
community. The Einstein Toolkit is currently funded by a collaborative
NSF grant to LSU, RIT, Georgia Tech, and Caltech.
I very strongly believe in open source and strive to make my
simulation codes and input physics publically available. Most of my 3D
supernova simulation tools are already public and part of the
. My grad student Evan O'Connor's code GR1D (see the GR1D code paper) is also available as open
source from our stellarcollapse.org
website. There we also host finite-temperature nuclear equation of state tables
and table reader/interpolation code.
- I am an active member of the LIGO Scientific Collaboration Burst
Data Analysis working group and am presently involved in a search for
gravitational waves from core-collapse supernovae. I am also trying to
understand how combined neutrino and gravitational wave observations
from the next galactic core-collapse supernova may be used to
constrain supernova physics and fundamental physics. My direct local
collaborator on this is my grad student Sarah Gossan.
With the Caltech-Cornell-CITA-WSU Simulating eXtreme Spacetimes (SXS)
collaboration I am studying the merger of neutron star - neutron
star and black hole - neutron star binaries. This research is primarily
funded by the Sherman Fairchild Foundation, NSF, and NASA. My direct
collaborators are my graduate student Jeff Kaplan,
Duez at WSU, Larry Kidder, Francois Foucart and Saul Teukolsky at
Cornell, Mark Scheel and Bela Szilagyi at Caltech.
I work with the Princeton supernova group (led by
Adam Burrows) on various topics in
core-collapse supernova theory. The current focus is 1D and multi-D neutrino
transport using Monte Carlo techniques.
(Complete ADS list)
(ADS short-author list only [no LIGO papers])
Recent Short Author List Work (since 2011):
P. Mösta, S. Richers, C. D. Ott, R. Haas, A. L. Piro, K. Boydstun, E. Abdikamalov, C. Reisswig, E. Schnetter, "Magnetorotational Core-Collapse Supernovae in Three Dimensions," submitted to ApJL (2014), (ads/arXiv).
P. Mösta, B. Mundim, J. Faber, R. Haas, S. Noble, T. Bode, F. Löffler, C. D. Ott, C. Reisswig, E. Schnetter, "GRHydro: A new open source general-relativistic magnetohydrodynamics code for the Einstein Toolkit," CQG 31, 015005 (2014), (ads).
E. Abdikamalov, S. Gossan, A. DeMaio, C. D. Ott, "Measuring the Angular Momentum Distribution in Core-Collapse Supernova Progenitors with Gravitational Waves," submitted to PRD (2013), (ads/arXiv).
S. M. Couch and C. D. Ott, "Revival of the Stalled Core-collapse Supernova Shock Triggered by Precollapse Asphericity in the Progenitor Star," ApJ 778, L7 (2013),(ads).
C. Reisswig, C. D. Ott, E. Abdikamalov, R. Haas, P. Moesta, E. Schnetter, "Formation and Coalescence of Cosmological Supermassive Black Hole Binaries in Supermassive Star Collapse," PRL 111, 151101 (2013), (ads).
J. D. Kaplan, C. D. Ott, E. P. O'Connor, K. Kiuchi, L. Roberts, M. Duez, "The Influence of Thermal Pressure on Hypermassive Neutron Star Merger Remnants," submitted to ApJ (2013), (ads/arXiv).
M. B. Deaton, M. Duez, F. Foucart, E. O'Connor, C. D. Ott, L. Kidder, C. Muhlberger, M. Scheel, B. Szilagyi, "Black Hole-Neutron Star Mergers with a Hot Nuclear Equation of State: Outflow and Neutrino-Cooled Disk for a Low-Mass, High-Spin Case," ApJ 776, 47 (2013), (ads).
F. Foucart, M. B. Deaton, M. Duez, L. Kidder, I. MacDonald, C. D. Ott, H. Pfeiffer, M. Scheel, B. Szilagyi, S. Teukolsky, "Black-hole-neutron-star mergers at realistic mass ratios: Equation of state and spin orientation effects," Phys. Rev. D. 87, 084006 (2013), (ads).
C. Reisswig, R. Haas, C. D. Ott, E. Abdikamalov, P. Moesta, D. Pollney, and E. Schnetter,
"Three-Dimensional General-Relativistic Hydrodynamic Simulations of Binary Neutron Star Coalescence and Stellar Collapse with Multipatch Grids," Phys. Rev. D. 87, 064023 (2013), (ads)
C. D. Ott, E. Abdkimalov, P. Moesta, R. Haas, S. Drasco, E. O'Connor, C. Reisswig, C. Meakin, and E. Schnetter, "General-Relativistic Simulations of Three-Dimensional Core-Collapse Supernovae," ApJ 768, 115 (2013), (ads).
O. Korobkin, E. Abdikamalov, N. Stergioulas, E. Schnetter, B. Zink, S. Rosswog, and C. D. Ott, "The runaway instability in general-relativistic accretion disks," MNRAS, 431, 349 (2013), (ads).
D. Radice, E. Abdikamalov, L. Rezzolla, and C. D. Ott, "A New Spherical Harmonics Scheme for Multi-Dimensional Radiation Transport I: Static Matter Configurations," J. Comp. Phys. 242, 648 (2013), (ads).
E. O'Connor and C. D. Ott, "The Progenitor Dependence of the Preexplosion Neutrino Emission in Core-Collapse Supernovae," ApJ 762, 126 (2013), (ads).
C. Horowitz, G. Shen, E. O'Connor, and C. D. Ott, "Charged current neutrino interactions in core-collapse supernovae in a virial expansion," Phys. Rev. C. 86, 065806 (2012), (ads).
C. D. Ott, E. Abdikamalov, E. O'Connor, C. Reisswig, R. Haas, P. Kalmus, S. Drasco, A. Burrows, and E. Schnetter, "Correlated Gravitational Wave and Neutrino Signals from General-Relativistic Rapidly Rotating Iron Core Collapse," Phys. Rev. D. 86, 024026 (2012), (ads).
E. Abdikamalov, A. Burrows, C. D. Ott, F. Loeffler, E. O'Connor, J. Dolence, E. Schnetter, "A New Monte Carlo Method for Time-Dependent Neutrino Radiation Transport," ApJ 755, 111 (2012), (ads).
L. Dessart, E. O'Connor, C. D. Ott, "The Arduous Journey to Black-Hole Formation in Potential Gamma-Ray Burst Progenitors,", ApJ 754, 76 (2012), (ads)
J. Logue, C. D. Ott, I. S. Heng, P. Kalmus, J. Scargill, "Inferring Core-Collapse Supernova Physics with Gravitational Waves," Phys. Rev. D. 86, 044023 (2012), (ads).
- B. Dasgupta, E. O'Connor, C. D. Ott, "Role of collective neutrino flavor oscillations in core-collapse supernova shock revival,"
Phys. Rev. D. 84, 065008 (2012), (ads).
- A. Piro, C. D. Ott, "Supernova Fallback onto Magnetars and Propeller-powered Supernovae,", Astrophys. J. 736, 108 (2011), (ads).
- E. Thrane, S. Kandhasamy, C. D. Ott, et al., "Long gravitational-wave transients and associated detection strategies for a network of terrestrial interferometers,", Phys. Rev. D. 83, 083004 (2011), (ads).
- C. D. Ott, C. Reisswig, E. Schnetter, E. O'Connor, U. Sperhake, F. Löller, P. Diener, E. Abdikamalov, I. Hawke, and A. Burrows, "Dynamics and Gravitational Wave Signature of Collapsar Formation,", Phys. Rev. Lett 106, 161103 (2011), (ads)
- C. Reisswig, C. D. Ott, U. Sperhake, and E. Schnetter, "Gravitational wave extraction in simulations of rotating stellar core collapse,", Phys. Rev. D. 83, 064008 (2011), (ads)
- E. O'Connor and C. D. Ott, "Black Hole Formation in Failing Core-Collapse Supernovae," ApJ 730, 70 (2011),
- T. Brandt, A. Burrows, E. Livne, C. D. Ott, "Results From Core-Collapse Simulations with Multi-Dimensional, Multi-Angle Neutrino Transport,", ApJ 728, 8 (2011), (ads)