HELIUM SHELL DETONATIONS ON LOW-MASS WHITE DWARFS AS A POSSIBLE EXPLANATION FOR SN 2005E

Journal Article · Thu Sep 01 00:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/738/1/21· OSTI ID:21582951

Waldman, Roni; Livne, Eli; Glasner, Ami ^[1]; Sauer, Daniel ^[2]; Perets, Hagai ^[3]; Mazzali, Paolo ^[4]; Truran, James W ^[5]; Gal-Yam, Avishay ^[6]

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1. Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)
2. Stockholm University, Department for Astronomy, AlbaNova University Center, 106 91 Stockholm (Sweden)
3. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
4. Max-Planck Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching (Germany)
5. Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States)
6. Benoziyo Center for Astrophysics, Faculty of Physics, Weizmann Institute of Science, Rehovot 76100 (Israel)

Recently, several Type Ib supernovae (SNe; with the prototypical SN 2005E) have been shown to have atypical properties. These SNe are faint (absolute peak magnitude of {approx} - 15) and fast SNe that show unique composition. They are inferred to have low ejecta mass (a few tenths of a solar mass) and to be highly enriched in calcium, but poor in silicon elements and nickel. These SNe were therefore suggested to belong to a new class of calcium-rich faint SNe explosions. Their properties were proposed to be the result of helium detonations that may occur on helium accreting white dwarfs. In this paper, we theoretically study the scenario of helium detonations and focus on the results of detonations in accreted helium layers on low-mass carbon-oxygen (CO) cores. We present new results from one-dimensional simulations of such explosions, including their light curves and spectra. We find that when the density of the helium layer is low enough the helium detonation produces large amounts of intermediate elements, such as calcium and titanium, together with a large amount of unburnt helium. Alternatively, enough carbon enrichment of the accreted helium as a result of convective undershoot at the early stages of the runaway can avoid the production of iron group elements as the alpha particles are consumed avoiding iron production. Our results suggest that the properties of calcium-rich faint SNe could indeed be consistent with the helium-detonation scenario on small CO cores. Above a certain density (larger CO cores) the detonation leaves mainly {sup 56}Ni and unburnt helium, and the predicted spectrum will unlikely fit the unique features of this class of SNe. Finally, none of our studied models reproduces the bright, fast-evolving light curves of another type of peculiar SNe suggested to originate in helium detonations (SNe 1885A, 1939B, and 2002bj).

• OSTI ID: 21582951
• Journal Information: Astrophysical Journal, Vol. 738, Issue 1; Other Information: DOI: 10.1088/0004-637X/738/1/21; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
CARBON MONOXIDE
EXPLOSIONS
HELIUM
NICKEL 56
ONE-DIMENSIONAL CALCULATIONS
SIMULATION
SUPERNOVAE
WHITE DWARF STARS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BINARY STARS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
DAYS LIVING RADIOISOTOPES
DWARF STARS
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
ERUPTIVE VARIABLE STARS
EVEN-EVEN NUCLEI
FLUIDS
GASES
INTERMEDIATE MASS NUCLEI
ISOTOPES
NICKEL ISOTOPES
NONMETALS
NUCLEI
OXIDES
OXYGEN COMPOUNDS
RADIOISOTOPES
RARE GASES
STARS
VARIABLE STARS