تقرير
Nearby Supernova Factory Observations of SN 2007if: First Total Mass Measurement of a Super-Chandrasekhar-Mass Progenitor
| العنوان: | Nearby Supernova Factory Observations of SN 2007if: First Total Mass Measurement of a Super-Chandrasekhar-Mass Progenitor |
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| المؤلفون: | Scalzo, R. A., Aldering, G., Antilogus, P., Aragon, C., Bailey, S., Bongard, C., Buton, C., Childress, M., Chotard, N., Copin, Y., Fakhouri, H. K., Gal-Yam, A., Gangler, E., Hoyer, S., Kasliwal, M., Loken, S., Nugent, P. E., Pain, R., Pecontal, E., Pereira, R., Perlmutter, S., Rabinowitz, D., Rau, A., Rigaudier, G., Runge, K., Smadja, G., Tao, C., Thomas, R. C., Weaver, B., Wu, C. |
| المصدر: | Astrophysical Journal 713, 1073-1094 (2010) |
| سنة النشر: | 2010 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena |
| الوصف: | We present photometric and spectroscopic observations of SN 2007if, an overluminous (M_V = -20.4), red (B-V = 0.16 at B-band maximum), slow-rising (t_rise = 24 days) type Ia supernova in a very faint (M_g = -14.10) host galaxy. A spectrum at 5 days past B-band maximum light is a direct match to the super-Chandrasekhar-mass candidate SN Ia 2003fg, showing Si II and C II at ~9000 km/s. A high signal-to-noise co-addition of the SN spectral time series reveals no Na I D absorption, suggesting negligible reddening in the host galaxy, and the late-time color evolution has the same slope as the Lira relation for normal SNe Ia. The ejecta appear to be well mixed, with no strong maximum in I-band and a diversity of iron-peak lines appearing in near-maximum-light spectra. SN2007 if also displays a plateau in the Si II velocity extending as late as +10 days, which we interpret as evidence for an overdense shell in the SN ejecta. We calculate the bolometric light curve of the SN and use it and the \ion{Si}{2} velocity evolution to constrain the mass of the shell and the underlying SN ejecta, and demonstrate that SN2007 if is strongly inconsistent with a Chandrasekhar-mass scenario. Within the context of a "tamped detonation" model appropriate for double-degenerate mergers, and assuming no host extinction, we estimate the total mass of the system to be 2.4 +/- 0.2 solar masses, with 1.6 +/- 0.1 solar masses of nickel-56 and with 0.3-0.5 solar masses in the form of an envelope of unburned carbon/oxygen. Our modeling demonstrates that the kinematics of shell entrainment provide a more efficient mechanism than incomplete nuclear burning for producing the low velocities typical of super-Chandrasekhar-mass SNeIa. Comment: 23 pages, 13 figures, 4 tables, emulateapj format; v2 fixed some typos and added a reference; v3 included minor copy-editing changes + fixed typos in Figure 9, Table 4; accepted to ApJ |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1088/0004-637X/713/2/1073 |
| URL الوصول: | http://arxiv.org/abs/1003.2217 |
| رقم الأكسشن: | edsarx.1003.2217 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1088/0004-637X/713/2/1073 |
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