scholarly journals SN 2014J in M82: new insights on the spectral diversity of Type Ia supernovae

2018 ◽  
Vol 481 (1) ◽  
pp. 878-893 ◽  
Author(s):  
Kaicheng Zhang ◽  
Xiaofeng Wang ◽  
JuJia Zhang ◽  
Tianmeng Zhang ◽  
S Benetti ◽  
...  
Keyword(s):  
High Velocity ◽  
Type Ia Supernovae ◽  
High Resolution Spectrum ◽  
Low Velocity ◽  
Maximum Light ◽  
Velocity Gradients ◽  
Type Ia ◽  
Ia Supernovae ◽  
Photospheric Temperature

ABSTRACT We present extensive spectroscopic observations for one of the closest Type Ia supernovae (SNe Ia), SN 2014J discovered in M82, ranging from 10.4 d before to 473.2 d after B-band maximum light. The diffuse interstellar band features detected in a high-resolution spectrum allow an estimate of line-of-sight extinction as Av ∼ 1.9 ± 0.6 mag. Spectroscopically, SN 2014J can be put into the high-velocity (HV) subgroup in Wang’s classification with a velocity of Si ii λ 6355 at maximum light of $v$0 = 1.22 ± 0.01 × 104 km s−1 but has a low velocity gradient (LVG, following Benetti’s classification) of $\dot{v}=41\pm 2$ km s−1 d−1, which is inconsistent with the trend that HV SNe Ia generally have larger velocity gradients. We find that the HV SNe Ia with LVGs tend to have relatively stronger Si iii (at ∼4400 Å) absorptions in early spectra, larger ratios of S ii λ 5468 to S ii λ 5640, and weaker Si ii 5972 absorptions compared to their counterparts with similar velocities but high velocity gradients. This shows that the HV+LVG subgroup of SNe Ia may have intrinsically higher photospheric temperature, which indicates that their progenitors may experience more complete burning in the explosions relative to the typical HV SNe Ia.

scholarly journals Exploring the shell model of high-velocity features of Type Ia supernovae using tardis

2019 ◽  
Vol 484 (4) ◽  
pp. 4785-4800 ◽  
Author(s):  
Brian W Mulligan ◽  
Kaicheng Zhang ◽  
J Craig Wheeler
Keyword(s):  
Shell Model ◽  
High Velocity ◽  
Type Ia Supernovae ◽  
Type Ia ◽  
Ia Supernovae

scholarly journals Type IA Supernovae

1992 ◽  
Vol 151 ◽  
pp. 225-234
Author(s):  
J. Craig Wheeler
Keyword(s):  
White Dwarf ◽  
Cataclysmic Variables ◽  
Type Ia Supernovae ◽  
Low Velocity ◽  
Severe Problem ◽  
Transfer Rates ◽  
Secular Evolution ◽  
Thermonuclear Explosion ◽  
Type Ia ◽  
Ia Supernovae

Spectral calculations show that a model based on the thermonuclear explosion of a degenerate carbon/oxygen white dwarf provides excellent agreement with observations of Type Ia supernovae. Identification of suitable evolutionary progenitors remains a severe problem. General problems with estimation of supernova rates are outlined and the origin of Type Ia supernovae from double degenerate systems are discussed in the context of new rates of explosion per H band luminosity, the lack of observed candidates, and the likely presence of H in the vicinity of some SN Ia events. Re-examination of the problems of triggering Type Ia by accretion of hydrogen from a companion shows that there may be an avenue involving cataclysmic variables, especially if extreme hibernation occurs. Novae may channel accreting white dwarfs to a unique locus in accretion rate/mass space. Systems that undergo secular evolution to higher mass transfer rates could lead to just the conditions necessary for a Type Ia explosion. Tests involving fluorescence or absorption in a surrounding circumstellar medium and the detection of hydrogen stripped from a companion, which should appear at low velocity inside the white dwarf ejecta, are suggested. Possible observational confirmation of the former is described.

scholarly journals Type Ia Supernova Models and Progenitor Scenarios

2011 ◽  
Vol 7 (S281) ◽  
pp. 253-260
Author(s):  
Ken'ichi Nomoto ◽  
Yasuomi Kamiya ◽  
Naohito Nakasato
Keyword(s):  
White Dwarf ◽  
Emission Lines ◽  
Type Ia Supernovae ◽  
Theoretical Studies ◽  
Low Velocity ◽  
Dynamical Phase ◽  
Type Ia ◽  
Recent Developments ◽  
Ia Supernovae ◽  
Interesting Constraint

AbstractWe review some recent developments in theoretical studies on the connection between the progenitor systems of Type Ia supernovae (SNe Ia) and the explosion mechanisms. (1) DD-subCh: In the merging of double C+O white dwarfs (DD scenario), if the carbon detonation is induced near the white dwarf (WD) surface in the early dynamical phase, it could result in the (effectively) sub-Chandrasekhar mass explosion. (2) DD-Ch: If no surface C-detonation is ignited, the WD could grow until the Chandrasekhar mass is reached, but the outcome depends on whether the quiescent carbon shell burning is ignited and burns C+O into O+Ne+Mg. (3) SD-subCh: In the single degenerate (SD) scenario, if the He shell-flashes grow strong to induce a He detonation, it leads to the sub-Chandra explosion. (4) SD-Ch: If the He-shell flashes are not strong enough, they still produce interesting amounts of Si and S near the surface of the C+O WD before the explosion. In the Chandra mass explosion, the central density is high enough to produce electron capture elements, e.g., stable 58Ni. Observations of the emission lines of Ni in the nebular spectra provides useful diagnostics of the sub-Chandra vs. Chandra issue. The recent observations of relatively low velocity carbon near the surface of SNe Ia provide also an interesting constraint on the explosion models.

scholarly journals On the Progenitors of Type Ia Supernovae

2011 ◽  
Vol 7 (S281) ◽  
pp. 303-308
Author(s):  
Mario Livio
Keyword(s):  
Velocity Gradient ◽  
Degenerate Case ◽  
Type Ia Supernovae ◽  
Spherically Symmetric ◽  
Velocity Gradients ◽  
Main Class ◽  
Type Ia ◽  
The Asymmetry ◽  
Ia Supernovae

AbstractI propose two new means of identifying the main class of progenitors of Type Ia supernovae – single or double degenerate: (i) If the range of supernova properties is significantly determined by the range of viewing angles of non-spherically symmetric explosions, then the nature of the correlation between polarization and another property (for example, the velocity gradient) can be used to determine the geometry of the asymmetry and hence the nature of the progenitor, and (ii) in the double- but not in the single-degenerate case, the range in the observed properties (e.g., velocity gradients) is likely to increase with the amount of carbon seen in the ejecta.

How Similar are Type Ia Supernovae?

1994 ◽  
Vol 11 (1) ◽  
pp. 65-67 ◽  
Author(s):  
Raylee A. Stathakis ◽  
Elaine M. Sadler
Keyword(s):  
Wavelength Region ◽  
Spectral Lines ◽  
Type Ia Supernovae ◽  
Expansion Velocity ◽  
Evolutionary Trend ◽  
Maximum Light ◽  
Galaxy Type ◽  
Type Ia ◽  
Ia Supernovae ◽  
Parent Galaxy

AbstractWe have compared the spectra of six Type Ia supernovae, at ages between 4 and 404 days after maximum light, to see whether all show similar evolutionary behaviour. We find that the spectral lines between 6800 Å and 8000 Å follow a smooth evolutionary trend, but that lines redward of 8000 Å show significant differences. SN 1987I and SN 19880 show extra emission over a broader wavelength region, possibly due to OI 8446 Å emission which would indicate higher envelope densities for these objects. Our results are consistent with the trend of expansion velocity with parent galaxy type reported by Branch and van den Bergh (1993). Variations within the class of Ia SNe may affect their use as standard candles.

scholarly journals High-velocity features of calcium and silicon in the spectra of Type Ia supernovae

2015 ◽  
Vol 451 (2) ◽  
pp. 1973-2014 ◽  
Author(s):  
Jeffrey M. Silverman ◽  
József Vinkó ◽  
G. H. Marion ◽  
J. Craig Wheeler ◽  
Barnabás Barna ◽  
...  
Keyword(s):  
High Velocity ◽  
Type Ia Supernovae ◽  
Type Ia ◽  
Ia Supernovae

scholarly journals HUBBLE SPACE TELESCOPE STUDIES OF NEARBY TYPE Ia SUPERNOVAE: THE MEAN MAXIMUM LIGHT ULTRAVIOLET SPECTRUM AND ITS DISPERSION

2011 ◽  
Vol 727 (2) ◽  
pp. L35 ◽  
Author(s):  
Jeff Cooke ◽  
Richard S. Ellis ◽  
Mark Sullivan ◽  
Peter Nugent ◽  
D. Andrew Howell ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Ultraviolet Spectrum ◽  
Type Ia Supernovae ◽  
Space Telescope ◽  
Maximum Light ◽  
Type Ia ◽  
The Mean ◽  
Ia Supernovae

scholarly journals Carnegie Supernova Project: The First Homogeneous Sample of Super-Chandrasekhar-mass/2003fg-like Type Ia Supernovae

2021 ◽  
Vol 922 (2) ◽  
pp. 205
Author(s):  
C. Ashall ◽  
J. Lu ◽  
E. Y. Hsiao ◽  
P. Hoeflich ◽  
M. M. Phillips ◽  
...  
Keyword(s):  
Light Curves ◽  
Type Ia Supernovae ◽  
Homogeneous Sample ◽  
Band Maximum ◽  
Maximum Light ◽  
Nir Light ◽  
Near Ir ◽  
Large Spread ◽  
Type Ia ◽  
Ia Supernovae

Abstract We present a multiwavelength photometric and spectroscopic analysis of 13 super-Chandrasekhar-mass/2003fg-like Type Ia supernovae (SNe Ia). Nine of these objects were observed by the Carnegie Supernova Project. The 2003fg-like SNe have slowly declining light curves (Δm 15(B) < 1.3 mag), and peak absolute B-band magnitudes of −19 < M B < −21 mag. Many of the 2003fg-like SNe are located in the same part of the luminosity–width relation as normal SNe Ia. In the optical B and V bands, the 2003fg-like SNe look like normal SNe Ia, but at redder wavelengths they diverge. Unlike other luminous SNe Ia, the 2003fg-like SNe generally have only one i-band maximum, which peaks after the epoch of the B-band maximum, while their near-IR (NIR) light-curve rise times can be ≳40 days longer than those of normal SNe Ia. They are also at least 1 mag brighter in the NIR bands than normal SNe Ia, peaking above M H = −19 mag, and generally have negative Hubble residuals, which may be the cause of some systematics in dark-energy experiments. Spectroscopically, the 2003fg-like SNe exhibit peculiarities such as unburnt carbon well past maximum light, a large spread (8000–12,000 km s−1) in Si ii λ6355 velocities at maximum light with no rapid early velocity decline, and no clear H-band break at +10 days. We find that SNe with a larger pseudo-equivalent width of C ii at maximum light have lower Si ii λ6355 velocities and more slowly declining light curves. There are also multiple factors that contribute to the peak luminosity of 2003fg-like SNe. The explosion of a C–O degenerate core inside a carbon-rich envelope is consistent with these observations. Such a configuration may come from the core-degenerate scenario.

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