scholarly journals New Mass Limit for White Dwarfs: Super-Chandrasekhar Type Ia Supernova as a New Standard Candle

2013 ◽  
Vol 110 (7) ◽  
Author(s):  
Upasana Das ◽  
Banibrata Mukhopadhyay
Keyword(s):  
White Dwarfs ◽  
Mass Limit ◽  
Type Ia Supernova ◽  
Standard Candle ◽  
Type Ia

scholarly journals Significantly super-Chandrasekhar mass-limit of white dwarfs in noncommutative geometry

2021 ◽  
Vol 30 (05) ◽  
pp. 2150034
Author(s):  
Surajit Kalita ◽  
Banibrata Mukhopadhyay ◽  
T. R. Govindarajan
Keyword(s):  
White Dwarf ◽  
White Dwarfs ◽  
Compact Object ◽  
Type Ia Supernovae ◽  
Mass Limit ◽  
Fusion Reactions ◽  
Standard Candle ◽  
Type Ia ◽  
Nuclear Fusion Reactions ◽  
Ia Supernovae

Chandrasekhar made the startling discovery about nine decades back that the mass of compact object white dwarf has a limiting value once nuclear fusion reactions stop therein. This is the Chandrasekhar mass-limit, which is [Formula: see text] for a nonrotating non-magnetized white dwarf. On approaching this limiting mass, a white dwarf is believed to spark off with an explosion called type Ia supernova, which is considered to be a standard candle. However, observations of several over-luminous, peculiar type Ia supernovae indicate the Chandrasekhar mass-limit to be significantly larger. By considering noncommutativity among the components of position and momentum variables, hence uncertainty in their measurements, at the quantum scales, we show that the mass of white dwarfs could be significantly super-Chandrasekhar and thereby arrive at a new mass-limit [Formula: see text], explaining a possible origin of over-luminous peculiar type Ia supernovae. The idea of noncommutativity, apart from the Heisenberg’s uncertainty principle, is there for quite sometime, without any observational proof however. Our finding offers a plausible astrophysical evidence of noncommutativity, arguing for a possible second standard candle, which has many far-reaching implications.

scholarly journals Lens modelling of the strongly lensed Type Ia supernova iPTF16geu

2020 ◽  
Vol 496 (3) ◽  
pp. 3270-3280
Author(s):  
E Mörtsell ◽  
J Johansson ◽  
S Dhawan ◽  
A Goobar ◽  
R Amanullah ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Hubble Constant ◽  
Host Galaxy ◽  
Total Probability ◽  
Lens Model ◽  
Density Profiles ◽  
Type Ia Supernova ◽  
Standard Candle ◽  
Type Ia ◽  
Universal Expansion

ABSTRACT In 2016, the first strongly lensed Type Ia supernova (SN Ia), iPTF16geu, at redshift z = 0.409 with four resolved images arranged symmetrically around the lens galaxy at z = 0.2163, was discovered. Here, refined observations of iPTF16geu, including the time delay between images, are used to decrease uncertainties in the lens model, including the the slope of the projected surface density of the lens galaxy, Σ ∝ r1 − η, and to constrain the universal expansion rate H0. Imaging with Hubble Space Telescope provides an upper limit on the slope η, in slight tension with the steeper density profiles indicated by imaging with Keck after iPTF16geu had faded, potentially due to dust extinction not corrected for in host galaxy imaging. Since smaller η implies larger magnifications, we take advantage of the standard candle nature of SNe Ia constraining the image magnifications, to obtain an independent constraint of the slope. We find that a smooth lens density fails to explain the iPTF16geu fluxes, regardless of the slope, and additional substructure lensing is needed. The total probability for the smooth halo model combined with star microlensing to explain the iPTF16geu image fluxes is maximized at 12 per cent for η ∼ 1.8, in excellent agreement with Keck high-spatial-resolution data, and flatter than an isothermal halo. It also agrees perfectly with independent constraints on the slope from lens velocity dispersion measurements. Combining with the observed time delays between the images, we infer a lower bound on the Hubble constant, $H_0 \gtrsim 40\, {\rm km \ s^{-1} Mpc^{-1}}$, at 68.3 per cent confidence level.

scholarly journals Nucleosynthesis imprints from different Type Ia supernova explosion scenarios and implications for galactic chemical evolution

2020 ◽  
Vol 644 ◽  
pp. A118
Author(s):  
F. Lach ◽  
F. K. Röpke ◽  
I. R. Seitenzahl ◽  
B. Coté ◽  
S. Gronow ◽  
...  
Keyword(s):  
Chemical Evolution ◽  
White Dwarfs ◽  
Supernova Explosion ◽  
Detailed Comparison ◽  
Galactic Chemical Evolution ◽  
Type Ia Supernova ◽  
Type Ia ◽  
Pure Helium ◽  
Ia Supernovae ◽  
Insight Into

We analyze the nucleosynthesis yields of various Type Ia supernova explosion simulations including pure detonations in sub-Chandrasekhar mass white dwarfs; double detonations and pure helium detonations of sub-Chandrasekhar mass white dwarfs with an accreted helium envelope; a violent merger model of two white dwarfs; and deflagrations and delayed detonations in Chandrasekhar mass white dwarfs. We focus on the iron peak elements Mn, Zn, and Cu. To this end, we also briefly review the different burning regimes and production sites of these elements, as well as the results of abundance measurements and several galactic chemical evolution studies. We find that super-solar values of [Mn/Fe] are not restricted to Chandrasekhar mass explosion models. Scenarios including a helium detonation can significantly contribute to the production of Mn, in particular the models proposed for calcium-rich transients. Although Type Ia supernovae are often not accounted for as production sites of Zn and Cu, our models involving helium shell detonations can produce these elements in super-solar ratios relative to Fe. Our results suggest a re-consideration of Type Ia supernova yields in galactic chemical evolution models. A detailed comparison with observations can provide new insight into the progenitor and explosion channels of these events.

scholarly journals SN 2010LP—A TYPE IA SUPERNOVA FROM A VIOLENT MERGER OF TWO CARBON-OXYGEN WHITE DWARFS

2013 ◽  
Vol 778 (1) ◽  
pp. L18 ◽  
Author(s):  
M. Kromer ◽  
R. Pakmor ◽  
S. Taubenberger ◽  
G. Pignata ◽  
M. Fink ◽  
...  
Keyword(s):  
White Dwarfs ◽  
Type Ia Supernova ◽  
Type Ia

scholarly journals NEW MASS LIMIT OF WHITE DWARFS

2013 ◽  
Vol 22 (12) ◽  
pp. 1342004 ◽  
Author(s):  
UPASANA DAS ◽  
BANIBRATA MUKHOPADHYAY
Keyword(s):  
Paradigm Shift ◽  
White Dwarfs ◽  
Type Ia Supernovae ◽  
Mass Limit ◽  
Type Ia ◽  
Ia Supernovae ◽  
Distance Indicators ◽  
The Way

Is the Chandrasekhar mass limit for white dwarfs (WDs) set in stone? Not anymore, recent observations of over-luminous, peculiar type Ia supernovae can be explained if significantly super-Chandrasekhar WDs exist as their progenitors, thus barring them to be used as cosmic distance indicators. However, there is no estimate of a mass limit for these super-Chandrasekhar WD candidates yet. Can they be arbitrarily large? In fact, the answer is no! We arrive at this revelation by exploiting the flux freezing theorem in observed, accreting, magnetized WDs, which brings in Landau quantization of the underlying electron degenerate gas. This essay presents the calculations which pave the way for the ultimate (significantly super-Chandrasekhar) mass limit of WDs, heralding a paradigm shift 80 years after Chandrasekhar's discovery.

scholarly journals An upper limit on the contribution of accreting white dwarfs to the type Ia supernova rate

Nature ◽  
2010 ◽  
Vol 463 (7283) ◽  
pp. 924-925 ◽  
Author(s):  
Marat Gilfanov ◽  
Ákos Bogdán
Keyword(s):  
White Dwarfs ◽  
Upper Limit ◽  
Type Ia Supernova ◽  
Type Ia

scholarly journals Type Ia Supernovae from Sub-Chandrasekhar Mass White Dwarfs

2011 ◽  
Vol 7 (S281) ◽  
pp. 267-274
Author(s):  
Stuart A. Sim ◽  
Friedrich K. Röpke ◽  
Markus Kromer ◽  
Michael Fink ◽  
Ashley J. Ruiter ◽  
...  
Keyword(s):  
White Dwarfs ◽  
Binary Systems ◽  
Light Curves ◽  
Type Ia Supernovae ◽  
Type Ia Supernova ◽  
Type Ia ◽  
Ia Supernovae

AbstractWe argue that detonations of sub-Chandrasekhar mass white dwarfs can lead to bright explosions with light curves and spectra similar to those of observed Type Ia supernovae. Given that binary systems containing accreting sub-Chandrasekhar mass white dwarfs should be common, this suggests that a non-negligible fraction of the observed Type Ia supernova rate may arise from sub-Chandrasekhar mass explosions, if they can be ignited. We discuss aspects of how such explosions might be realized in nature and both merits and challenges associated with invoking sub-Chandrasekhar mass explosion models to account for observed Type Ia supernovae.

Stellar Metallicities and Type Ia Supernova Rates in the Early‐Type Galaxy NGC 5846 fromROSATandASCAObservations

1999 ◽  
Vol 514 (2) ◽  
pp. 844-855 ◽  
Author(s):  
A. Finoguenov ◽  
C. Jones ◽  
W. Forman ◽  
L. David
Keyword(s):  
Early Type ◽  
Type Ia Supernova ◽  
Type Ia ◽  
Early Type Galaxy
Sign in / Sign up

Export Citation Format

Share Document