@article{2014ApJ...781...42O,
 abstract = {Some supernovae (SNe) may be powered by the interaction of the SN ejecta
with a large amount of circumstellar matter (CSM). However,
quantitative estimates of the CSM mass around such SNe are
missing when the CSM material is optically thick. Specifically,
current estimators are sensitive to uncertainties regarding the
CSM density profile and the ejecta velocity. Here we outline a
method to measure the mass of the optically thick CSM around
such SNe. We present new visible-light and X-ray observations of
SN 2010jl (PTF 10aaxf), including the first detection of an SN
in the hard X-ray band using NuSTAR. The total radiated
luminosity of SN 2010jl is extreme—at least 9
× 10$^50$ erg. By modeling the visible-light
data, we robustly show that the mass of the circumstellar
material within åisebox-0.5ex~10$^16$ cm
of the progenitor of SN 2010jl was in excess of 10 M $_☉$.
This mass was likely ejected tens of years prior to the SN
explosion. Our modeling suggests that the shock velocity during
shock breakout was \i̊sebox-0.5ex~6000 km
s$^-1$, decelerating to \rs̊ebox-0.5ex~2600
km s$^-1$ about 2 yr after maximum light. Furthermore, our
late-time NuSTAR and XMM spectra of the SN presumably provide
the first direct measurement of SN shock velocity 2 yr after the
SN maximum light—measured to be in the range of
2000-4500 km s$^-1$ if the ions and electrons are in
equilibrium, and &gt;\rae̊box-0.5ex~ 2000 km
s$^-1$ if they are not in equilibrium. This measurement is in
agreement with the shock velocity predicted by our modeling of
the visible-light data. Our observations also show that the
average radial density distribution of the CSM roughly follows
an r $^-2$ law. A possible explanation for the
&gt;\raib̊ox-0.5ex~ 10 M $_☉$ of CSM and the
wind-like profile is that they are the result of multiple
pulsational pair instability events prior to the SN explosion,
separated from each other by years.},
 adsnote = {Provided by the SAO/NASA Astrophysics Data System},
 adsurl = {https://ui.adsabs.harvard.edu/abs/2014ApJ...781...42O},
 archiveprefix = {arXiv},
 author = {Ofek, <NAME>. and Zoglauer, Andreas and Boggs, <NAME>. and
Barriére, <NAME>. and Reynolds, <NAME>. and
Fryer, <NAME>. and Harrison, <NAME>. and <NAME> and
Kulkarni, <NAME>. and Gal-Yam, Avishay and <NAME> and
Bellm, Eric and Bloom, <NAME>. and Christensen, Finn and
Craig, <NAME>. and <NAME> and Filippenko, <NAME>. and
Grefenstette, Brian and Hailey, <NAME>. and <NAME> and
Madsen, Kristin and Nakar, Ehud and Nugent, <NAME>. and
Stern, Daniel and Sullivan, Mark and Surace, Jason and
Zhang, <NAME>.},
 doi = {10.1088/0004-637X/781/1/42},
 eid = {42},
 eprint = {1307.2247},
 journal = {\apj},
 keywords = {stars: mass-loss, supernovae: general, supernovae: individual: SN 2010jl, Astrophysics - High Energy Astrophysical Phenomena},
 month = {Jan},
 number = {1},
 pages = {42},
 primaryclass = {astro-ph.HE},
 title = {SN 2010jl: Optical to Hard X-Ray Observations Reveal an Explosion Embedded in a Ten Solar Mass Cocoon},
 volume = {781},
 year = {2014}
}

