High luminosity, slow ejecta and persistent carbon lines: SN 2009dc challenges thermonuclear explosion scenarios

By Stefan Taubenberger, S. Benetti, M. Childress, Rüdiger Pakmor, Stephan Hachinger, P. Mazzali, V. Stanishev, N. Elias-Rosa, I. Agnoletto, Filomena Bufano and 15 more. 2010

176 citations recorded by the source corpus.

Extended optical and near-IR observations reveal that SN 2009dc shares a number of similarities with normal Type Ia supernovae (SNe Ia), but is clearly overluminous, with a (pseudo-bolometric) peak luminosity of log (L) = 43.47 (erg s^(−1)). Its light curves decline slowly over half a year after maximum light [Δm_(15)(B)_true= 0.71], and the early-time near-IR light curves show secondary maxima, although the minima between the first and the second peaks are not very pronounced. The bluer bands exhibit an enhanced fading after ~200 d, which might be caused by dust formation or an unexpectedly early IR catastrophe. The spectra of SN 2009dc are dominated by intermediate-mass elements and unburned material at early times, and by iron-group elements at late phases. Strong C ii lines are present until ~2 weeks past maximum, which is unprecedented in thermonuclear SNe. The ejecta velocities are significantly lower than in normal and even subluminous SNe Ia. No signatures of interaction with a circumstellar medium (CSM) are found in the spectra. Assuming that the light curves are powered by radioactive decay, analytic modelling suggests that SN 2009dc produced ~1.8 M_⊙ of ^(56)Ni assuming the smallest possible rise time of 22 d. Together with a derived total ejecta mass of ~2.8 M_⊙, this confirms that SN 2009dc is a member of the class of possible super-Chandrasekhar-mass SNe Ia similar to SNe 2003fg, 2006gz and 2007if. A study of the hosts of SN 2009dc and other superluminous SNe Ia reveals a tendency of these SNe to explode in low-mass galaxies. A low metallicity of the progenitor may therefore be an important prerequisite for producing superluminous SNe Ia. We discuss a number of possible explosion scenarios, ranging from super-Chandrasekhar-mass white-dwarf progenitors over dynamical white-dwarf mergers and Type I(1/2) SNe to a core-collapse origin of the explosion. None of the models seems capable of explaining all properties of SN 2009dc, so that the true nature of this SN and its peers remains nebulous.

Subfields: Astronomy and Astrophysics, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/1f58f5f2840115fcccd9c0eca46857a436b65eed

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. A. Filippenko
2. D. Maoz
3. F. Mannucci
4. Ryan Chornock
5. R. Kirshner
6. S. Jha
7. E. Berger
8. N. Smith

In Electrical and Electronic Engineering

1. D. Maoz
2. F. Mannucci
3. G. Nelemans
4. A. Riess
5. A. Filippenko
6. S. Jha
7. A. Gal-yam
8. Ryan Chornock

Citations in the corpus

• THE SPECTROSCOPIC DIVERSITY OF TYPE Ia SUPERNOVAE (2000, background): “…for SN 2002cx and MB ≈ −18.0mag for SN 2005hk; see Phillips et al. 2007) nor luminous (possibly super-Chandrasekhar) events (e.g., SN 2006gz with MB ≈ −19.9, Hicken et al. 2007a; or SN 2009dc with MB ≈ −20.2, Taubenberger et al. 2011) since BayeSN did not include such SN Ia in its training set.”
• TYPE Ia SUPERNOVAE STRONGLY INTERACTING WITH THEIR CIRCUMSTELLAR MEDIUM (2013, background): “In addition, the so-called super-Chandrasekhar mass SNe Ia are thought to contain > 1.4 M of SN ejecta and thus are likely formed from the DD scenario (e.g., Howell et al. 2006; Yamanaka et al. 2009; Scalzo et al. 2010; Silverman et al. 2011; Taubenberger et al. 2011).”
• Observational Clues to the Progenitors of Type Ia Supernovae (2013, background): “At the other extreme, the nickel mass deduced for some very bright SN Ia explosions is suggestive of a super-Chandrasekhar-mass progenitor, with mass ∼> 2M (e.g. Howell et al. 2006, Kamiya et al. 2012, Scalzo et al. 2012, 2010, Silverman et al. 2011, Taubenberger et al. 2011, 2013a).”
• A COMPACT DEGENERATE PRIMARY-STAR PROGENITOR OF SN 2011fe (2011, background): “However, the discovery of a class of SNe Ia that require a WD mass above the Chandrasekhar limit (Howell et al. 2006) has caused some to question whether a WD is involved in the explosion after all (Taubenberger et al. 2011).”
• Stellar structure models in modified theories of gravity: Lessons and challenges (2019, background): “c . (313) The discovery of highly over-luminous supernovae (SNe Ia), raises the suggestion of the existence of super Chandrasekharwhite dwarfs as their progenitors,with a mass in the range 2.1− 2.8M⊙ [518, 519, 520, 521, 522], offering further avenues to test EiBI gravity (and other modified theories ”
• On the Progenitors of Type Ia Supernovae (2018, unknown): “Following the first such event (Howell et al. 2006), a few other caes have been found, with SN 2007if (Yuan et al. 2010; Scalzo et al. 2010; Childress et al. 2011) and SN 2009dc (Taubenberger et al. 2011) being among the best observed.”