436 research outputs found
The Impact of Progenitor Mass Loss on the Dynamical and Spectral Evolution of Supernova Remnants
There is now substantial evidence that the progenitors of some core-collapse
supernovae undergo enhanced or extreme mass loss prior to explosion. The
imprint of this mass loss is observed in the spectra and dynamics of the
expanding blastwave on timescales of days to years after core-collapse, and the
effects on the spectral and dynamical evolution may linger long after the
supernova has evolved into the remnant stage. In this paper, we present for the
first time, largely self-consistent end-to-end simulations for the evolution of
a massive star from the pre-main sequence, up to and through core collapse, and
into the remnant phase. We present three models and compare and contrast how
the progenitor mass loss history impacts the dynamics and spectral evolution of
the supernovae and supernova remnants. We study a model which only includes
steady mass loss, a model with enhanced mass loss over a period of 5000
years prior to core-collapse, and a model with extreme mass loss over a period
of 500 years prior to core collapse. The models are not meant to address
any particular supernova or supernova remnant, but rather to highlight the
important role that the progenitor evolution plays in the observable qualities
of supernovae and supernova remnants. Through comparisons of these three
different progenitor evolution scenarios, we find that the mass loss in late
stages (during and after core carbon burning) can have a profound impact on the
dynamics and spectral evolution of the supernova remnant centuries after
core-collapse.Comment: 18 pages, 11 figures; submitted to the Astrophysical Journa
A decade of ejecta dust formation in the Type IIn SN 2005ip
In order to understand the contribution of core-collapse supernovae to the
dust budget of the early universe, it is important to understand not only the
mass of dust that can form in core-collapse supernovae but also the location
and rate of dust formation. SN 2005ip is of particular interest since dust has
been inferred to have formed in both the ejecta and the post-shock region
behind the radiative reverse shock. We have collated eight optical archival
spectra that span the lifetime of SN 2005ip and we additionally present a new
X-shooter optical-near-IR spectrum of SN 2005ip at 4075d post-discovery. Using
the Monte Carlo line transfer code DAMOCLES, we have modelled the blueshifted
broad and intermediate width H, H and He I lines from 48d to
4075d post-discovery using an ejecta dust model. We find that dust in the
ejecta can account for the asymmetries observed in the broad and intermediate
width H, H and He I line profiles at all epochs and that it is
not necessary to invoke post-shock dust formation to explain the blueshifting
observed in the intermediate width post-shock lines. Using a Bayesian approach,
we have determined the evolution of the ejecta dust mass in SN 2005ip over 10
years presuming an ejecta dust model, with an increasing dust mass from
~10 M at 48d to a current dust mass of 0.1 M.Comment: Accepted by MNRAS, 17 pages, 11 figures. Author accepted manuscript.
Accepted on 04/03/19. Deposited on 07/03/1
Dust in the wind: the role of recent mass loss in long gamma-ray bursts
We study the late-time (t>0.5 days) X-ray afterglows of nearby (z<0.5) long
Gamma-Ray Bursts (GRB) with Swift and identify a population of explosions with
slowly decaying, super-soft (photon index Gamma_x>3) X-ray emission that is
inconsistent with forward shock synchrotron radiation associated with the
afterglow. These explosions also show larger-than-average intrinsic absorption
(NH_x,i >6d21 cm-2) and prompt gamma-ray emission with extremely long duration
(T_90>1000 s). Chance association of these three rare properties (i.e. large
NH_x,i, super-soft Gamma_x and extreme duration) in the same class of
explosions is statistically unlikely. We associate these properties with the
turbulent mass-loss history of the progenitor star that enriched and shaped the
circum-burst medium. We identify a natural connection between NH_x,i Gamma_x
and T_90 in these sources by suggesting that the late-time super-soft X-rays
originate from radiation reprocessed by material lost to the environment by the
stellar progenitor before exploding, (either in the form of a dust echo or as
reprocessed radiation from a long-lived GRB remnant), and that the interaction
of the explosion's shock/jet with the complex medium is the source of the
extremely long prompt emission. However, current observations do not allow us
to exclude the possibility that super-soft X-ray emitters originate from
peculiar stellar progenitors with large radii that only form in very dusty
environments.Comment: 6 pages, Submitted to Ap
Synthetic red supergiant explosion model grid for systematic characterization of Type II supernovae
A new model grid containing 228,016 synthetic red supergiant explosions (Type
II supernovae) is introduced. Time evolution of spectral energy distributions
from 1 A to 50,000 A (100 frequency bins in a log scale) is computed at each
time step up to 500 days after explosion in each model. We provide light curves
for the filters of the Vera C. Rubin Observatory's Legacy Survey of Space and
Time (LSST), Zwicky Transient Facility (ZTF), Sloan Digital Sky Servey (SDSS),
and the Neil Gehrels Swift Observatory, but light curves for any photometric
filters can be constructed by convolving any filter response functions to the
synthetic spectral energy distributions. We also provide bolometric light
curves and photosphere information such as photospheric velocity evolution. The
parameter space covered by the model grid is five progenitor masses (10, 12,
14, 16, and 18 Msun at the zero-age main sequence, solar metallicity), ten
explosion energies (0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0 x
10^51 erg), nine 56Ni masses (0.001, 0.01, 0.02, 0.04, 0.06, 0.08, 0.1, 0.2,
and 0.3 Msun), nine mass-loss rates (1e-5.0, 1e-4.5, 1e-4.0, 1e-3.5, 1e-3.0,
1e-2.5, 1e-2.0, 1e-1.5, and 1e-1.0 Msun/yr with a wind velocity of 10 km/s),
six circumstellar matter radii (1, 2, 4, 6, 8, and 10 x 10^14 cm), and ten
circumstellar structures (beta = 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5,
and 5.0). 56Ni is assumed to be uniformly mixed up to the half mass of a
hydrogen-rich envelope. This model grid can be a base for rapid
characterizations of Type II supernovae with sparse photometric sampling
expected in LSST through a Bayesian approach, for example. The model grid is
available at https://doi.org/10.5061/dryad.pnvx0k6sj.Comment: 15 pages, 10 figures, 2 tables, data available at
https://doi.org/10.5061/dryad.pnvx0k6s
Relativistic supernovae have shorter-lived central engines or more extended progenitors: the case of SN\,2012ap
Deep late-time X-ray observations of the relativistic, engine-driven, type Ic
SN2012ap allow us to probe the nearby environment of the explosion and reveal
the unique properties of relativistic SNe. We find that on a local scale of
~0.01 pc the environment was shaped directly by the evolution of the progenitor
star with a pre-explosion mass-loss rate <5x10^-6 Msun yr-1 in line with GRBs
and the other relativistic SN2009bb. Like sub-energetic GRBs, SN2012ap is
characterized by a bright radio emission and evidence for mildly relativistic
ejecta. However, its late time (t~20 days) X-ray emission is ~100 times fainter
than the faintest sub-energetic GRB at the same epoch, with no evidence for
late-time central engine activity. These results support theoretical proposals
that link relativistic SNe like 2009bb and 2012ap with the weakest observed
engine-driven explosions, where the jet barely fails to breakout. Furthermore,
our observations demonstrate that the difference between relativistic SNe and
sub-energetic GRBs is intrinsic and not due to line-of-sight effects. This
phenomenology can either be due to an intrinsically shorter-lived engine or to
a more extended progenitor in relativistic SNe.Comment: Version accepted to ApJ. Significantly broadened discussio
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