The most powerful explosions in the Universe EWASS 2012, Symposium 10: "30 years of Italian participation to ESO” The most powerful explosions in the Universe Genesis and evolution of Supernova and Gamma-Ray Burst Italian programs at ESO  Elena Pian - INAF, Trieste Astronomical Observatory

Supernovae The detection of SN1987A boosted the Supernova research at ESO In the 1990s, the ESO programs led by the Supernova group in Padova pioneered and developed the concept of Target-of-Opportunity on “unpredictable” sources

Absolute light curves of 87 SN Ia Diversity of SNIa Absolute light curves of 87 SN Ia m15(B) RTN per SNIa vicine No STD candles !!

Normal SNe Ia follow Phillips relation! Pskovskii – Phillips relation normal To me normal SNIa are those Sne that follow the Phillips relation (Bob already introduce this important relation when using SNIa as cosmological lighthouses) Altavilla et al. 2004

Photospheric velocities of SN Ia 13/09/2018 Si II 6355Å velocity evolution v . HVG 97 km/s/d LVG 37 km/s/d FAINT 87km/s/d ≈MB ≈MB+2 So, by 2004-2005 we were able to update David’s plot with well followed nearby Ia. As you can see, the main feature of a big dispersion in the exp. Velocity is still there, but now we may characterize different behaviors. In particular, we may note that the velocity evolution followed by the different Sne post maximum is more or less linear and may be fitted with a straight line. If we define as velocity gradient the slope of this line, we may divide our Ia sample, using this new paramater. HVG are then those Sne with higher velocity gradient, high expansion velocities and bigger velocity spread. While the LVG have lower velocity gradient, slower expansion velocity which has a smaller dispersion. The Faint one have velocity gradients similar to HVG, but have much slower exp velocities and most of all they are much less luminous then HVG+LVG by about 2 mag there seems to be at least two groups of SNIa: the green one with an low spread in the postmax velocity and post max slower velocity evolution. And the other SNIa with a big spread in velocity and much higher velocity evolution! Colors are coded originally as the line blueshift of lines of the given SN, but finally as gradient Green are more homogeneous !! SiII does not go slower than 9000 km/s Blue the SiII extends well inside No early data for Red Benetti et al. 2005

Velocity gradient vs. Δm15 HVG Faint The new three Ia classes can be better seen in this plot. The Ia that are more photometric similar (HVG-LVG, same Dm15) have more kinematic differences in terms of velocity gradient and expansion velocities, while faint have vel grad similar to HVG but much lower expansion velocities and luminosity (higher Dm15) LVG Benetti et al. 2005

orro diagram! Applying density structure of W7 13/09/2018 X M (NSE+IME) M (NSE) M (56Ni) M (54Fe + 58Ni) Applying density structure of W7 transform vexp(Si) in mass. By adding it to the NSE mass, we obtain a constant mass, 1.05±0.09 Msun , with NO Dependence on m15(B) SNe that produce less 56Ni Synthesize more IME ~0.09Msol Using the maximum expansion velocity of Si at the moment of the explosion and applying the W7 density structure we are able to transform velocity of Si at the moment of the explosion in the mass enclose by the Si layer. This mass is, then, the amount of mass which has been processed by the thermonuclear explosion. Then with the modeling the nebular spectra we have derived the amount of Fe produced in the explosion. The difference gives the amount of IME produced in the explosion!!! Then you see that Sne which produced a lot of Fe have synthesized less IME, and vice-versa. It deals with SNIa diversity, both from spect. and phot. point of view Normal here is intended ot only Branch normal but also 91T and 91bg !!! 00cx and 02cx not included! ~0.13Msol Mazzali et al. 2007

Gamma-Ray Bursts 28 February 1997: BeppoSAX starts localizing GRBs with arcminute accuracy: the “GRB afterglow era” has started ~100 keV About 250 GRBs have been followed up with ESO telescopes

GRB970228: first detection of X-ray and optical afterglow NTT + SUSI, 13 March 1997 T0 + 21 hours T0 + 8 days Van Paradijs et al. and the BeppoSAX team 1997 T0 + 8 hours T0 + 3 days BeppoSAX detection of X-ray afterglow Costa et al 1997

GRB990510 (z = 1.6): optical afterglow Lin. Pol. 1.7±0.2% VLT+FORS ESO NTT and 3.6m The time decay is not a single power-law Israel et al. 1999 Covino et al. 1999

The optically brightest GRB (z = 0.937) (z = 6.29) (z = 1.6) Bloom et al. 2009

GRB080319B: the robotic approach REM+TORTORA Racusin et al. 2008

GRB080319B: VLT in Rapid Response Mode with UVES Fe II λ2374 Fe II λ2396* z = 0.937 Detection of variable absorption lines and identification of 6 absorbers in a velocity range of 100 km/s D’Elia et al. 2009

Metallicity of GRB host galaxies VLT+X-shooter Piranomonte et al. 2011

25 April 1998: Gamma-Ray Bursts meet Supernovae

GRB980425 Supernova 1998bw (Type Ic) z = 0.0085 Kinetic energy ~e52 erg

Light Curves of GRB and XRF Supernovae at z < 0.3 Pian et al. 2006 Bufano et al. 2012 Melandri et al. 2012

Photospheric velocities of Type Ic SNe Pian et al. 2006 Bufano et al. 2012

Summary A constant burned mass and a common explosion mechanism for Type Ia Supernovae: This may help in understanding their role as standard candles GRB optical flashes and afterglows: Study of physics (photometry and multiwavelength comparison) and environments (spectroscopy) GRB and XRF Supernovae: highly energetic Type Ic SNe. GRB SNe are more luminous than XRF SNe. Is this telling us something about progenitors and remnants?

The Future NTT Supernova Large Program PI: S. Benetti Public ESO Spectroscopic Survey for Transient Objects (PESSTO) PI: S. Smartt, important Italian role with S. Benetti and S. Valenti VLT FORS Type Ib/c and IIb Supernova program (late phase) PI: P. Mazzali VLT X-Shooter GTO TOO program (Denmark, France, Italy The Netherlands) PI: J. Fynbo, Italian Co-PI: S. Covino VLT X-Shooter GTO program on GRB host galaxies PI: S. Piranomonte VLT FORS GRB and X-ray Flash Supernova program PI: E. Pian and M. Della Valle