MEASURED METALLICITIES AT THE SITES OF NEARBY BROAD-LINED TYPE Ic SUPERNOVAE AND IMPLICATIONS FOR THE SUPERNOVAE GAMMA-RAY BURST CONNECTION
MEASURED METALLICITIES AT THE SITES OF NEARBY BROAD-LINED TYPE Ic SUPERNOVAE AND IMPLICATIONS FOR THE SUPERNOVAE GAMMA-RAY BURST CONNECTION
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附近宽线 Ic 型超新星位置的测量金属度及其对超新星伽马射线爆发连接的影响
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发表时间：
2007
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通讯作者：
KIPACStanford
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作者：
M. Modjaz;L. Kewley;R. Kirshner;K. Stanek;P. Challis;P. Garnavich;J. Greene;P. Kelly;J. L. P. CfA;U. Berkeley;U. Hawaii;Ohio State;Notre Dame;Princeton;KIPACStanford
我们比较了附近12个呈现宽线但没有观测到伽马射线暴(GRB)的(z<；0.14)型IC型超新星(SNIC)的化学丰度，并与附近5个(z<；0.25)星系的化学丰度进行了比较，这些星系是在火球消失后看到宽线的SNIC的。以前已经注意到，伽玛暴的宿主光度低，金属丰度低。如果低金属丰度足以迫使大质量恒星的演化以伽玛暴的形式结束它们的生命，伴随着宽线的锡离子，那么我们预计没有探测到伽玛暴的宽线锡离子的金属丰度会更高。这就是我们所观察到的，这一趋势与我们所采用的金属丰度校准的选择和发现宽线SnIC的SN调查模式无关。这种分析的一个独特之处在于，我们给出了宿主星系的新光谱，并用一套相同的方法分析了两个样本的所有测量结果，使用了经过消光和恒星吸收校正的星系发射线测量结果，通过Kewley&多普塔、McGaugh和Pettini&Pagel的独立金属丰度诊断。在我们的小样本中，有伽玛暴伴随其宽线SN IC的星系和那些具有宽线SN IC的星系之间的边界位于氧丰度12+log(O/H)KD02∼8.5，根据所采用的金属丰度和太阳丰度值，这相当于0.2-0.6Z☉。即使我们将比较局限于在非目标超新星探测中发现的SnIC，每一个没有伽玛暴的宽线SNIC的环境也比任何探测到伽玛暴的宽线SNIC的位置更富金属。
We compare the chemical abundances at the sites of 12 nearby (z < 0.14) Type Ic supernovae (SN Ic) that showed broad lines, but had no observed gamma-ray burst (GRB), with the chemical abundances in five nearby (z < 0.25) galaxies at the sites of GRBs where broad-lined SN Ic were seen after the fireball had faded. It has previously been noted that GRB hosts are low in luminosity and low in their metal abundances. If low metallicity is sufficient to force the evolution of massive stars to end their lives as GRBs with an accompanying broad-lined SN Ic, then we would expect higher metal abundances for the broad-lined SN Ic that have no detected GRBs. This is what we observe, and this trend is independent of the choice of metallicity calibration we adopt and the mode of SN survey that found the broad-lined SN Ic. A unique feature of this analysis is that we present new spectra of the host galaxies and analyze all measurements of both samples in the same set of methods, using the galaxy emission-line measurements corrected for extinction and stellar absorption, via independent metallicity diagnostics of Kewley & Dopita, McGaugh, and Pettini & Pagel. In our small sample, the boundary between galaxies that have GRBs accompanying their broad-lined SN Ic and those that have broad-lined SN Ic without GRBs lies at an oxygen abundance of 12 + log(O/H)KD02 ∼ 8.5, which corresponds to 0.2–0.6 Z☉ depending on the adopted metallicity scale and solar abundance value. Even when we limit the comparison to SN Ic that were found in untargeted supernova surveys, the environment of every broad-lined SN Ic that had no GRB is more metal rich than the site of any broad-lined SN Ic where a GRB was detected.