اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدRed and dead: The progenitor of SN 2012aw in M95
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Core-collapse supernovae (SNe) are the spectacular finale to massive stellar evolution. In this Letter, we identify a progenitor for the nearby core-collapse SN 2012aw in both ground based near-infrared, and space based optical pre-explosion imaging. The SN itself appears to be a normal Type II Plateau event, reaching a bolometric luminosity of 10$^{42}$ erg s$^{-1}$ and photospheric velocities of $sim$11,000 kms from the position of the H$beta$ P-Cygni minimum in the early SN spectra. We use an adaptive optics image to show that the SN is coincident to within 27 mas with a faint, red source in pre-explosion HST+WFPC2, VLT+ISAAC and NTT+SOFI images. The source has magnitudes $F555W$=26.70$pm$0.06, $F814W$=23.39$pm$0.02, $J$=21.1$pm$0.2, $K$=19.1$pm$0.4, which when compared to a grid of stellar models best matches a red supergiant. Interestingly, the spectral energy distribution of the progenitor also implies an extinction of $A_V>$1.2 mag, whereas the SN itself does not appear to be significantly extinguished. We interpret this as evidence for the destruction of dust in the SN explosion. The progenitor candidate has a luminosity between 5.0 and 5.6 log L/lsun, corresponding to a ZAMS mass between 14 and 26 msun (depending on $A_V$), which would make this one of the most massive progenitors found for a core-collapse SN to date.
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We present new late-time near-infrared imaging of the site of the nearby core-collapse supernova SN 2012aw, confirming the disappearance of the point source identified by Fraser et al. (2012) and Van Dyk et al. (2012) as a candidate progenitor in bot
h J and Ks filters. We re-measure the progenitor photometry, and find that both the J and Ks magnitudes of the source are consistent with those quoted in the literature. We also recover a marginal detection of the progenitor in H-band, for which we measure H=19.67+/-0.40 mag. Comparing the luminosity of the progenitor to stellar evolutionary models, SN 2012aw appears to have resulted from the explosion of a 12.5+/-1.5 Msun red supergiant.
We use natural seeing imaging of SN 2013ej in M74 to identify a progenitor candidate in archival {it Hubble Space Telescope} + ACS images. We find a source coincident with the SN in the {it F814W}-filter, however the position of the progenitor candid
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016gkg shows strong similarities with other Type IIb SNe, in particular with respect to the he~emission features observed in both the optical and near infrared. SN~2016gkg evolved faster than the prototypical Type~IIb SN~1993J, with a decline similar to that of SN~2011dh after the first peak. The analysis of archival {it Hubble Space Telescope} images indicate a pre-explosion source at SN~2016gkgs position, suggesting a progenitor star with a $sim$mid F spectral type and initial mass $15-20$msun, depending on the distance modulus adopted for NGC~613. Modeling the temperature evolution within $5,rm{days}$ of explosion, we obtain a progenitor radius of $sim,48-124$rsun, smaller than that obtained from the analysis of the pre-explosion images ($240-320$rsun).
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drodynamic model which simultaneously reproduced the photometry observations and velocity measurements. The model was calculated with the multi-energy group radiation hydrodynamics code STELLA. We found the parameters of the pre-supernova: radius $R = 500 R_odot$, nickel mass $M(^{56}$Ni$)$ $sim 0.06 M_odot$, pre-supernova mass $25 M_odot$, mass of ejected envelope $23.6 M_odot$, explosion energy $E sim 2 times 10^{51}$ erg. The model progenitor mass $M=25 M_odot$ significantly exceeds the upper limit mass $M=17 M_odot$, obtained from analysis the pre-SNe observations. This result confirms once more that the Red Supergiant Problem must be resolved by stellar evolution and supernova explosion theories in interaction with observations.
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