1 / 24

Studio fotometrico e spettroscopico di SN 1994Z, rara supernova IIP dal plateau brillante

Dipartimento di Astronomia, Universit à degli Studi di Padova INAF – Osservatorio Astronomico di Padova. Studio fotometrico e spettroscopico di SN 1994Z, rara supernova IIP dal plateau brillante. Irene Agnoletto. Geremeas (CA), 20-26 maggio 2007. Modern classification. Turatto, 2003.

tammy
Download Presentation

Studio fotometrico e spettroscopico di SN 1994Z, rara supernova IIP dal plateau brillante

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Dipartimento di Astronomia, Università degli Studi di Padova INAF – Osservatorio Astronomico di Padova Studio fotometrico e spettroscopico di SN 1994Z, rara supernova IIP dal plateau brillante Irene Agnoletto Geremeas (CA), 20-26 maggio 2007

  2. Modern classification Turatto, 2003

  3. Core collapsesupernovae:basic properties • originate from the energy liberated by the gravitational collapse of the nucleus of massive stars (> 8 M  ) • show H (typeII), He (except for type Ic), Ca, O, Mg, Fe • from small to huge radio to X-ray emissions • leave collapsed remnant (NS or BH) • emit neutrinos and gravitational waves • occur only in late type galaxies and are associated with star forming regions • are very heterogeneous: large spread in luminosity, ejected Ni masses, light curves evolution…

  4. Presentation NGC 87 SN 1994Z • Discovered on October, 2.51 UT in the irregular galaxy NGC 87(Wassilief, IAUC n. 6087) • First mag. estimation: V ~ 16, (B-V)~0.1(on October 4th, by P. Philips at CTIO) • Spectra analysis => typical features of a II-P SN2-3 weeks after explosion (on October 4th, by S. Benetti and G. Hasinger on ESO 2.2m telescope spectra) TARGET OF ESO-KEY PROJECTS 1990-1996 H vel 3546 RA 00h,21m,16.6s DEC -48d,37m,49s

  5. Dataset ~ 500 days photometric coverage ~ 380 days spectroscopic coverage

  6. Basic Estimates for Photometry • Milky Way Reddening:AB,MW=0.084(Schlegel et al. 1998) • AB,pg=0No Host Galaxy reddening (no NaID, Turatto et al. 2003) • Distance through Hubble’s law vinfall=3371km/s (LEDA), H0=72±4 km/s/Mpc (Freedman, 2001):d= 46.81 Mpc = 33.35 • Explosion Date through comparison with similar objects:Dexpl=13 September 1994

  7. Photometric data reduction and results • Both aperture and PSF photometry with SNOoPY (Cappellaro & Patat) • Calibration through Landolt (1992) standard stars • Calibration of SN in not photometric nights through local sequence stars

  8. Plateau luminosity not perfectly constant for V, R, I bands V=1.07mag/100d

  9. U B I R V Absolute UBVRI light curves For comparison:

  10. Absolute magnitudes 94Z 96W 92H V band 96W 92H 87A 94Z 69L V band • Mmax,B ≤ -17.29 • <M>V,plat.~ -17.05, <M>R,plat.~ -17.32, <M>I,plat.~ -17.62 • Similar evolution to SN 1996W and SN 1992H (photosferic phase) but … standard luminosity tail!!

  11. M(56Ni)~0.07 M  (as for SN 1987A!) SN 2004et Pastorello (private communication) Colour… …And bolometric light curve

  12. Spectroscopy Photosferic phase FeII H Nebular phase CaII] FeII ScII NaID ScII H FeII [FeII] Tcont~6200K vph~2300km/s CaII-IR H H Tcont~13000K HeI H vph~9000km/s CaII] [OI] • Standard IRAF reduction procedure • Wavelength calibration through HeNe or HeAr lamps spectra • SN flux calibration through instrument sensitivity functions RESULT: THE WHOLE SPECTROSCOPIC EVOLUTION IS…

  13. Comparisons: SN 1992H H Velocity …therefore: Similar kinematics and structure of the nebulae

  14. But… OI line luminosity 6300-6364 CaII line luminosity 7291-7332 Different line luminosities H line luminosity Different Envelope masses, less massive for 94Z Less massive progenitor for SN 1994Z! MHenv~10M 

  15. Modelling • initial radius of the envelope • envelope mass • ejected 56Ni mass • velocity of the env. at the outer shell • explosion energy • luminosity at recombination Output parameters: • Comparison between obervational data(light curves, evolution of the line velocity and continuum temperature) andnumerical simulations (Zampieri et al. 2003) • Automatic data fitting

  16. Best fit Progenitor mass:~9.5M 

  17. Correlation among II-P SNe physical parameters See Hamuy et al (2003) Zampieri et al (2003) Zampieri (2006)

  18. Conclusions: • SN 1994Z belongs to the poor populated class of bright IIP SNe • Similar to SN 1996W and SN 1992H in brightness and kinematics at first stages, but with smaller amount of 56Ni ejected (maybe because of fallback??) • No evidence of Luminosity-Ni mass correlation!! (Hamuy, 2003) • High luminosity IIP supernovae can be associated with low mass progenitors • Standard physical parameters except for velocity • progenitor mass of ~9.5M  => consistent with the recent progenitor identifications!!(see Li et al., 2006 for SN 2005cs, Li et al., 2005b for SN 2004et, Hendry & Smartt 2006 for SN 2004A);

  19. Observational data  physical parameters (progenitor mass and radius, energetics and velocity of the explosion etc.)  nature, evolution Bright II-P supernovae are rare  More information are important, more data are necessary!

More Related