a panchromatic view of the restless sn2009ip reveals the explosive ejection of a massive stellar...
TRANSCRIPT
A panchromatic view of the restless SN2009ip reveals the explosive ejection of
a massive stellar envelope
Distance of 24 Mpc
In the outskirts of NGC7259
Sub-solar metallicity environment 0.4<Z<0.9 Zsun
Discovery
Aug
2009
Outburst
Jul 2
010
Outburst
Sep
2010
OutburstM
ay 2
011
Oct
201
1
Explosion2
Explosion1
Aug
2012
Sep
2012
5 kpc
Now
Supern
ova
Imposto
r
Supern
ova ?
The complete story…
Eruptions
2012
SN2009ip eruptions plus 2012 double explosion
UV-Optical-NIR photometry
“Precursor bump” Major explosion
We know the story of eruptions of the progenitor in the previous years
The explosion has a luminous PRECURSOR
Detection of the PROGENITOR star in pre-explosion images (Smith+10, Foley+11): the progenitor is a massive star with M>60 Msun
Why is SN2009ip so interesting?
SN2009ip vs. a sample of SNe IIn and the peculiar explosion 1961V
VLACARMA 13-filter
photometry + spectra
UVOT &
HST
XMMXRT
BATFermi-LAT
Our observational campaign:
…no wavelength is left behind… The extensive monitoring is critical to: (i) constrain Erad, the temperature and radius of the emission; (ii)
constrain the role of different emission processes that dominate at different wavelengths.Understand the global properties of the explosion
Low-energy explosion: Erad~3d49 erg NOT powered by Nickel!
40 days
August 2012“shell ejection”
September 2012The shock breaks out through the dense thick shell ejected by the
first explosion
A second explosions happens
The general picture:
Mshell~0.1 Msun
Lx / Lopt < 10-4
Lbol/1d4
X-rays:they peak around the same time of the optical emission
…however:
As expected for a shock break out through a dense medium
Radio:Delayed peak due to free-free absorption
SN2009ip is a weak radio and X-ray emitter!
The metamorphosis in the optical:
BUT…
No sign of freshly synthesized material, yetSee e.g. [OI]
Low-res UVOT spectral campaign
HST
Oct 29
Nov 06
Super SED around the time of the optical peak
NIR excess of emission
NIR campaign: NIR excess:
t=tpk-4.5d
The NIR excess is not due to line emission
GeV photons and neutrinos from shock break-out
Predicted muon and anti-muon neutrino fluence from SN 2009ip using the observables and explosion
parameters according to the model by Murase et al. (2011). For this event, the atmospheric neutrino
background is more severe since SN 2009ip occurred in the southern hemisphere. For better localized
explosions, this plot shows how limits on the neutrino emission can be used to constrain the energy in
cosmic rays (ECR).
The collision of the ejecta with massive shells is expected to accelerate cosmic rays (CRs) and generate GeV gamma- rays (Murase et al. 2011; Katz et al. 2011) with fluence that depends both on the
explosion and on the environment parameters. We use the parameters inferred from the modeling of the optical-UV emission with shock break out, to predict the expected GeV fluence. Fermi-
LAT upper-limits are shown with black circles.
DENSE and compact SHELLM~0.1 Msun
(ejected by the 2012 precursor)
R~5d14 cm
R>4d15 cm
NIR emitting material
ejected during the previous
years outbursts
E~1d50 ergMej~0.5 Msun
The general picture is that of a massive star that repeatedly ejects massive shells of material on a time scale of years and less
Presence of a dominant time-scale common to eruption episodes and the major explosion, shared by completely independent events
40 days
-- Causal connection between precursor and main explosion-- “SIMPLE” mechanism-- Important channel for mass loss
What triggers the sudden shell ejection?This is not clear. However, two observational facts are crucial to our understanding:
Extreme similarity to SN2010mc, which implies:
Note: this NOT a claim for periodicity
Evolved massive stars have a much less boring life than expected: they suffer repetitive shell ejection on short time scales, whose physical origin is
not understood, questioning our current understanding of massive star evolution.
SN2009ip (and 10mc) might have just shown us a new channel for impulsive and sustained mass loss.
Smith 2010; Foley 2011; Fraser 2013; Levesque 2013; Mauerhan 2013; Ofek 2013; Pastorello 2013; Prieto 2012; Smith 2013; Soker 2013Ref in the literature:
Take-away message