Upper limits on the luminosity of the progenitor of Type Ia supernova SN 2014J

Abstract

We analysed archival data of Chandra pre-explosion observations of the position of SN2014J in M82. No X-ray source at this position was detected in the data, and we calculated upper limits on the luminosities of the progenitor. These upper limits allow us to firmly rule out an unobscured supersoft X-ray source progenitor with a photospheric radius comparable to the radius of white dwarf near the Chandrasekhar mass (∼1.38 M ⊙ ) and mass accretion rate in the interval where stable nuclear burning can occur. However, due to a relatively large hydrogen column density implied by optical observations of the supernova, we cannot exclude a supersoft source with lower temperatures, kT 80 eV. We find that the supernova is located in the center of a large structure of soft diffuse emission, about 200 pc across. The mass, ∼ 3 · 10 4 M ⊙ and short cooling time of the gas, τ cool ∼ 8 Myrs, suggest that it is a supernovainflated super-bubble, associated with the region of recent star formation. If SN2014J is indeed located inside the bubble, it likely belongs to the prompt population of type Ia supernovae, with a delay time as short as ∼ 50 Myrs. Finally, we analysed the one existing post-supernova Chandra observation and placed upper limit of ∼ (1 − 2) · 10 37 erg/s on the X-ray luminosity of the supernova itself.

NO X-RAYS FROM THE VERY NEARBY TYPE Ia SN 2014J: CONSTRAINTS ON ITS ENVIRONMENT

“…Finally, thermonuclear burning of hydrogen rich material on the surface of a WD is expected to generate super-soft X-ray emission, which should be thus detectable in pre-explosion images at the SN site. Consistent with our findings above, Nielsen et al (2014) found no evidence for a super-soft X-ray source at the position of SN 2014J using deep Chandra X-ray observations spanning the time range 1 t 14 yr before explosion. These observations allowed Nielsen et al (2014) to rule out SD systems with high effective temperature of the super-soft emission kT eff > 80 eV.…”

“…We note that the use of this lower NH MW value would have no impact on our conclusions. 5 Based on pre-explosion Chandra observations, Nielsen et al (2014) infer NH int = (8.6 ± 0.4) × 10 21 cm −2 . However, the actual X-ray absorption affecting SN 2014J can be either smaller or larger, depending if SN 2014J exploded in front of some of the material responsible for the intrinsic hydrogen column in pre-explosion images or if instead SN 2014J illuminated additional material which was not contributing to the measured NH int .…”

The circumstellar matter of supernova 2014J and the core-degenerate scenario

“…If the mass distribution employed here is correct, then within about two years from the explosion, sometime in 2016, the infrared radiation from warming CSM dust might start to increase. (3) Nielsen et al (2014) argue that SN 2014J comes from a young population. A mass transfer from the initially more massive primary star, M10 ≈ 5−8M⊙, to the secondary could leave a massive secondary on the main sequence, M2 ≈ 7 − 8M⊙, that expelled such a large mass during the CE phase (Ilkov & Soker 2013), as in the case of PTF 11kx .…”

“…In the present study I examine some properties of the type Ia SN 2014J, concentrating on the medium around it. I take into account limits on the pre-explosion progenitor (Kelly et al 2014;Nielsen et al 2014;Lundqvist et al 2015) and its mass loss (Pérez-Torres et al 2014), and the properties of the absorption potassium lines (Ritchey et al 2014), and their time-variability (Graham et al 2015). ¿From radio observations Pérez-Torres et al (2014) limit the mass loss rate from the progenitor of SN 2014J to < 7.0 × 10 −10 M⊙ yr −1 for a wind speed of 100 km s −1 .…”

Time series of high-resolution spectra of SN 2014J observed with the TIGRE telescope

“…An answer to such diverse dynamics may be given by the hot superbubble discovered by Nielsen et al (2014). Its X-ray emission appears to coincide with the site of SN 2014J.…”