Photometric selection of Type Ia supernovae in the Supernova Legacy Survey
Photometric selection of Type Ia supernovae in the Supernova Legacy Survey
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DOI：
10.1051/0004-6361/201116898
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发表时间：
2011-09
影响因子：
6.5
通讯作者：
G. Bazin;V. Ruhlmann-Kleider;N. Palanque-Delabrouille;J. Rich;E. Aubourg;P. Astier;C. Balland;S. Basa;R. Carlberg;A. Conley;D. Fouchez;J. Guy;D. Hardin;I. Hook;D. Howell;R. Pain;K. Perrett;C. Pritchet;N. Regnault;M. Sullivan;N. Fourmanoit;S. González-Gaitán;C. Lidman;S. Perlmutter;P. Ripoche;E. Walker
中科院分区：
文献类型：
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作者：
G. Bazin;V. Ruhlmann-Kleider;N. Palanque-Delabrouille;J. Rich;E. Aubourg;P. Astier;C. Balland;S. Basa;R. Carlberg;A. Conley;D. Fouchez;J. Guy;D. Hardin;I. Hook;D. Howell;R. Pain;K. Perrett;C. Pritchet;N. Regnault;M. Sullivan;N. Fourmanoit;S. González-Gaitán;C. Lidman;S. Perlmutter;P. Ripoche;E. Walker
我们提出了一个样本的485光度确定的Ia型超新星候选人从CFHT超新星遗产调查（SNLS）的前三年的数据挖掘。这些图像被提交给独立于SNLS实时检测管道的延迟处理。所有瞬态事件的光变曲线在gM、rM、iM和zM滤波器中重建，并提交给自动顺序切割，以识别可能的超新星。纯噪声和长期变量事件被拒绝的光曲线形状标准。Ia型超新星的识别依赖于事件特征，这些事件特征与它们的光变曲线相拟合，假设这些事件是正常的Ia型超新星。光变曲线拟合器SALT 2用于此目的，将宿主星系的光度红移分配给测试事件。所选的485个候选样本比SNLS光谱鉴定所允许的样本深一个数量级。其他类型超新星的污染估计为4%。用这个放大的样本测试哈勃图残差允许我们直接测量由于光谱选择引起的Malmquist偏差。这一结果与SNLS 3年宇宙学分析中用于校正超新星Ia距离模量的精确蒙特卡罗估计完全一致。本文证明了一个光度选择的高红移超新星与已知的宿主星系红移的可行性，打开有趣的前景，从未来的大光度超新星Ia调查的宇宙学分析。
We present a sample of 485 photometrically identified Type Ia supernova candidates mined from the first three years of data of the CFHT SuperNova Legacy Survey (SNLS). The images were submitted to a deferred processing independent of the SNLS real-time detection pipeline. Light curves of all transient events were reconstructed in the gM, rM, iM and zM filters and submitted to automated sequential cuts in order to identify possible supernovae. Pure noise and long-term variable events were rejected by light curve shape criteria. Type Ia supernova identification relied on event characteristics fitted to their light curves assuming the events to be normal SNe Ia. The light curve fitter SALT2 was used for this purpose, assigning host galaxy photometric redshifts to the tested events. The selected sample of 485 candidates is one magnitude deeper than that allowed by the SNLS spectroscopic identification. The contamination by supernovae of other types is estimated to be 4%. Testing Hubble diagram residuals with this enlarged sample allows us to measure the Malmquist bias due to spectroscopic selections directly. The result is fully consistent with the precise Monte Carlo based estimate used to correct SN Ia distance moduli in the SNLS 3-year cosmological analyses. This paper demonstrates the feasibility of a photometric selection of high redshift supernovae with known host galaxy redshifts, opening interesting prospects for cosmological analyses from future large photometric SN Ia surveys.