Research Homepage of Christian D. Ott
Welcome!
I am a computational/theoretical astrophysicist in TAPIR, which is part of the
Walter Burke Institute for
Theoretical Physics at Caltech, working at the interface of
numerical relativity, nuclear/neutrino astrophysics, and
gravitationalwave physics. My current primary research interest is to
find ways to blow up massive stars, that is, make corecollapse
supernovae and gammaray 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, Lauren Gilbert 
Grad students:  Sarah Gossan,
Hannalore GerlingDunsmore, Lena Murchikova, Maria
Okounkova, Sherwood
Richers (DOE CSGF),
Jonas Lippuner,
Joshua Blumenkopf,
Matt Giesler,
Kevin Barkett,
Jon Blackman, Mathieu Renzo (exchange grad
from Pisa) 
Postdocs 
Sebastiano Bernuzzi (joining fall 2014),
Drew Clausen (DuBridge Prize Fellow),
Daniel Hemberger,
Philipp Mösta,
Viktoriya Morozova,
David Radice (Sherman Fairchild Prize Fellow),
Christian Reisswig (Einstein Fellow),
Luke Roberts (Einstein Fellow),
Patricia Schmidt (joining fall 2014),
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) 
Ott Research Group Alumni
The SXS collaboration is supported by NSF, DOE, The Alfred P. Sloan Foundation, and by the Sherman Fairchild Foundation.
Research Opportunities
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
committees.
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 quasichronological order)
 2014/03/05 Magnetorotational CoreCollapse 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 gardenvariety supernova from a
massive star?
Detailed simulations show that the standard mechanism for
corecollapse 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 protoneutron star with a millisecond spin period) in
combination with a very strong toroidal magnetic field
(10^{15}10^{16} 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,
dynamicalspacetime GRmagnetohydrodynamic simulations of
magnetorotational corecollapse supernovae. This work was led by postdoc
Philipp Mösta
and grad
student Sherwood
Richers (DOE Computational Science Graduate Fellow) made important
contributions.
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
k_{B}/baryon), blue low entropy (a few
k_{B}/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 protoneutron 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 opensource 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 100inch 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 multimessenger followup observations of gravitational wave detections in the Advanced LIGO/Virgo era.
CGWAS will take place July 2226, 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 CoreCollapse Supernova Paper is out!
arXiv:1210.6674:
GeneralRelativistic Simulations of ThreeDimensional CoreCollapse Supernovae
We ran four full 3D full GR (timeevolving Einstein's field equations)
simulations of a 27solarmass 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
varied.
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, neutrinodriven 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 smallscale 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 20122014 Alfred P. Sloan Research Fellow.
(Announcement).

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!

2011/06/2024 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 coorganized 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
here.

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!
Older News
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 corecollapse
supernovae with the ultimate goal of connecting precollapse conditions
to the various possible outcomes of stellar collapse and their multimessenger
(photons, neutrinos, gravitational waves) signatures.

I am a member of the Einstein Toolkit
that aims to provide well tested and documented opensource
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
Einstein Toolkit
. My former graduate 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 finitetemperature 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 corecollapse supernovae. I am also trying to
understand how combined neutrino and gravitational wave observations
from the next galactic corecollapse 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 CaltechCornellCITAWSU 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.

I work with the Princeton supernova group (led by
Adam Burrows) on various topics in
corecollapse supernova theory. The current focus is 1D and multiD neutrino
transport using Monte Carlo techniques.
Publications
(Complete ADS list),
(ADS shortauthor list only [no LIGO papers]),
Recent Short Author List Work (since 2011):

E. Abdikamalov, S. Gossan, A. DeMaio, C. D. Ott, "Measuring the Angular Momentum Distribution in CoreCollapse Supernova Progenitors with Gravitational Waves," accepted for publication in PRD (2014), (ads/arXiv).

F. Foucart, B. Deaton, M. Duez, E. O'Connor, C. D. Ott, R. Haas, L. Kidder, H. Pfeiffer, M. Scheel, B. Szilagyi, "Neutron starblack hole mergers with a nuclear equation of state and neutrino cooling: Dependence in the binary parameters,", Phys. Rev. D. 90, 024026 (2014), (ads).

J. D. Kaplan, C. D. Ott, E. P. O'Connor, K. Kiuchi, L. Roberts, M. Duez, "The Influence of Thermal Pressure on Equilibrium Models of Hypermassive Neutron Star Merger Remnants," ApJ 790, 19 (2014), (ads).

D. Clausen, A. L. Piro, and C. D. Ott, "The Black Hole Formation Probability," submitted to ApJ, (ads/arXiv).

W. Engels, R. Frey, and C. D. Ott, "Multivariate Regression Analysis of Gravitational Waves from Rotating Core Collapse," submitted to PRD, (ads/arXiv).

C. Muhlberger, F. H. Nouri, M. Duez, F. Foucart, L. Kidder, C. D. Ott, M. Scheel, B. Szilagyi, and S. Teukolsky, "Magnetic effects on the lowT/W instability in differentially rotating neutron stars," submitted to PRD, (ads/arXiv).

P. Mösta, S. Richers, C. D. Ott, R. Haas, A. L. Piro, K. Boydstun, E. Abdikamalov, C. Reisswig, E. Schnetter, "Magnetorotational CoreCollapse Supernovae in Three Dimensions," ApJ, 785, L29 (2014), (ads).

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 generalrelativistic magnetohydrodynamics code for the Einstein Toolkit," CQG 31, 015005 (2014), (ads).

S. M. Couch and C. D. Ott, "Revival of the Stalled Corecollapse 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).

M. B. Deaton, M. Duez, F. Foucart, E. O'Connor, C. D. Ott, L. Kidder, C. Muhlberger, M. Scheel, B. Szilagyi, "Black HoleNeutron Star Mergers with a Hot Nuclear Equation of State: Outflow and NeutrinoCooled Disk for a LowMass, HighSpin 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, "Blackholeneutronstar 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,
"ThreeDimensional GeneralRelativistic 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, "GeneralRelativistic Simulations of ThreeDimensional CoreCollapse 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 generalrelativistic accretion disks," MNRAS, 431, 349 (2013), (ads).

D. Radice, E. Abdikamalov, L. Rezzolla, and C. D. Ott, "A New Spherical Harmonics Scheme for MultiDimensional 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 CoreCollapse Supernovae," ApJ 762, 126 (2013), (ads).

C. Horowitz, G. Shen, E. O'Connor, and C. D. Ott, "Charged current neutrino interactions in corecollapse 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 GeneralRelativistic 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 TimeDependent Neutrino Radiation Transport," ApJ 755, 111 (2012), (ads).

L. Dessart, E. O'Connor, C. D. Ott, "The Arduous Journey to BlackHole Formation in Potential GammaRay Burst Progenitors,", ApJ 754, 76 (2012), (ads)

J. Logue, C. D. Ott, I. S. Heng, P. Kalmus, J. Scargill, "Inferring CoreCollapse 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 corecollapse supernova shock revival,"
Phys. Rev. D. 84, 065008 (2012), (ads).
 A. Piro, C. D. Ott, "Supernova Fallback onto Magnetars and Propellerpowered Supernovae,", Astrophys. J. 736, 108 (2011), (ads).
 E. Thrane, S. Kandhasamy, C. D. Ott, et al., "Long gravitationalwave 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 CoreCollapse Supernovae," ApJ 730, 70 (2011),
(ads)
 T. Brandt, A. Burrows, E. Livne, C. D. Ott, "Results From CoreCollapse Simulations with MultiDimensional, MultiAngle Neutrino Transport,", ApJ 728, 8 (2011), (ads)