1 / 31

The Delay Time Distribution of Type Ia Supernovae: Constraints on Progenitors

The Delay Time Distribution of Type Ia Supernovae: Constraints on Progenitors Chris Pritchet (U. Victoria), Mark Sullivan (Oxford), Damien LeBorgne (IAP), Matt Taylor (PUC Chile), + SNLS Collaboration. SNe Ia CC SNe. or. Mt Wash Feb 2009. SNe Ia.

howie
Download Presentation

The Delay Time Distribution of Type Ia Supernovae: Constraints on Progenitors

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. The Delay Time Distribution of Type Ia Supernovae: Constraints on Progenitors Chris Pritchet (U. Victoria), Mark Sullivan (Oxford), Damien LeBorgne (IAP), Matt Taylor (PUC Chile), + SNLS Collaboration

  2. SNe Ia CC SNe or UWO Sep 2009 Mt Wash Feb 2009

  3. SNe Ia progenitor mechanism – 2 broad classes or energy release COFe no H in spectrum light curve shape presence in old stellar pops UWO Sep 2009 Mt Wash Feb 2009

  4. Single Degenerate - white dwarf + 2ndary evol. (M ~ 1.4 Msun at explosion) SN Ia Progenitors - 2 Broad Classes Double Degenerate - 2 white dwarfs (Mtot >= 1.4 Msun at explosion) Key point: white dwarf maximum mass M = 1.4 Msun (Chandrasekhar mass)

  5. SNe Ia progenitor mechanism – 2 broad classes or energy release COFe no H in spectrum light curve shape presence in old stellar pops UWO Sep 2009 Mt Wash Feb 2009

  6. Type Ia SNe as Standard Candles • Bright - seen to cosmological distances • Max brightness makes an excellent standard candle - ±6% distance errors • Standard candle seems to have a physical basis • SNeIa are “well-understood” - thermonuclear disruptions of C+O white dwarfs - std physics • Systematics – possibly, but ample opportunity to study with potentially hundreds of objects • But … • explanation of stretch – L relation • explanation of colour – L relation • nature of scatter in L after calibration • nature of progenitor

  7. Delay time distribution • DTD(t) = rate of supernovae as a function of time from a burst of star formation • SNR(t) = SFR(t) ★ DTD(t) DTD(t) SNe/yr/1010 M SFR(t) log t

  8. Importance of DTD(t) • potential to discriminate among progenitor models Greggio 2005

  9. DTD History • pre-1990 – “prevailing wisdom” was that all SN Ia were old because they occur in E/S0 galaxies • by 2004 – SNe Ia have higher rates in young galaxies – both young and old progenitors

  10. Recent DTD Determinations • from age/SFH estimates of SN host and field galaxies (SN age ~ galaxy age) Totani et al 2008: Subaru/XMM survey 65 variable objects ages from SED fitting

  11. Recent DTD Determinations • from age/SFH estimates of SN host and field galaxies Maoz et al 2010: LOSS survey 82 SNeIa SFH from SDSS Maoz

  12. Supernova Legacy Survey (SNLS) • 2003-2008, 4 deg2, ugriz, 4d samples, CFHT 3.6m+MegaCam • spec types and z (VLT, Gemini, Keck) - 370 SNeIa (0.2<z<1)

  13. DTD from SNLS • completeness estimate and weight for each supernova • host galaxy age for each supernova … • assumes host age = SN progenitor age • … and an age for all other objects too • gives total available mass at a given age

  14. z distribution and completeness SNIa* SNIa • Perrett et al 2011

  15. SN weighting SNe / year (all fields, rest-frame) Perrett et al 2011 # of observing seasons length of each observing season

  16. Pegase/zpeg ages and redshifts • mass, SFR, age, z for different evol scenarios

  17. DTD Calculation • Use only SNe with hosts in magnitude-limited catalogue • assumes that SN DTD does not depend on host galaxy mass • In each time bin of DTD t1t2, sum wi values for SNe with t1<ti<t2; normalize by host mass in time bin:

  18. 2 different M(t) methods • 0.2 < z < 0.75, 4 SNLS fields (3.6 deg2) • dashed=SFR(z), solid=zpeg SED fits SFR(z) log M log M(t) Hopkins and Beacom 2006 log t

  19. DTD • other z ranges give the same result

  20. DTD from 2 different M(t) methods • 0.2 < z < 0.75, red=SFR(z), black=obs

  21. Comparison with Totani et al 2008 t-1 Totani Mannucci

  22. Power-law fit t-1.35

  23. Two power laws t-0.7 t-3 cutoff real

  24. Comparison with DD solid – Mennekens et al 2010 dotted – Ruiter et al 2009 dashed – Yungelson and Livio 2000

  25. Comparison with SD solid – Mennekens et al 2010 dotted – Ruiter et al 2009 dashed – Hachisu et al 1999 dash dot – Han and Podsiadlowski 2004

  26. Further corrections • Have assumed that TSN=<Thost>. Not necessarily true • iterative approach to correct statistically • correction for dead stars • slope steeper by ~0.1 • effects of bursts • effects of catastrophic errors in M or age

  27. Supernova light curve stretch s Making a standard candle aka Phillips relation

  28. Stretch dependence of DTD • not due to age systematics • two types of progenitors?? or …

  29. Conclusions • SNIa DTD may be more complex than a simple ~ 1/t power-law • match to DD population synthesis models • pop syn needs further work • s<1 and >1 show differences in DTD below 109 yr – different progenitors? or PDF of ages?

More Related