THE GOLDEN STANDARD TYPE Ia SUPERNOVA 2005cf: OBSERVATIONS FROM THE ULTRAVIOLET TO THE NEAR-INFRARED WAVEBANDS-猫眼课题宝

DOI：

10.1088/0004-637x/697/1/380

发表时间：

2008-11

期刊：

The Astrophysical Journal

影响因子：

通讯作者：

中科院分区：

其他

文献类型：

作者：

Xiaofeng Wang;Weidong Li;A. Filippenko;R. Foley;R. Kirshner;M. Modjaz;J. Bloom;P. Brown;D. Carter;A. Friedman;A. Gal-Yam;M. Ganeshalingam;M. Hicken;K. Krisciunas;P. Milne;N. Suntzeff;W. M. Wood-Vasey;S. Cenko;P. Challis;D. Fox;D. Kirkman;J. Li;T. Li;M. Malkan;D. Reitzel;R. Rich;F. Serduke;R. Shang;J. Silverman;T. Steele;B. Swift;C. Tao;D. S. Wong;S. Berkeley;Tsinghua Univ.;Harvard-Smithsonian Cfa;Penn. State Univ.;Liverpool John Moores Univ.;Weizmann Institute of Science;Texas AM Univ.;S. Observatory;U. Pittsburgh;Caltech;Ucsd;Ucla;Cppm

我们在紫外（UV），光学和近红外（NIR）波长，以及密集的光谱采样，为正常的Ia型超新星（SN Ia）2005 cf。在八个不同的望远镜上进行的光学测光，在对仪器响应进行适当的校正后，显示出1σ散射为10.03等。从光变曲线的良好取样中，我们发现SN 2005 cf在13.63 ± 0.02等处达到B带最大值，观测到的光度下降率Δm15（B）= 1.05 ± 0.03等。得到SN 2005 cf主星系变红的一致估计，E（B − V）主星系= 0.10 ± 0.03 mag.紫外测光是用哈勃太空望远镜和雨燕紫外/光学望远镜获得的，结果在0.1-0.2 mag. UV光变曲线显示出与宽带U相似的演化，除了在2000-2500 nm光谱范围外（对应于F220 W/uvm 2滤光片），其中光变曲线看起来比两侧更宽且更暗（可能是由于固有的光谱演变）。结合紫外数据与地面光学和近红外数据，我们建立了通用的紫外-光学-近红外辐射热光度曲线SN 2005 cf和推导出的辐射热校正的紫外和/或近红外数据的情况下。SN 2005 cf的整体光谱演化与正常的Ia型超新星相似，但主要特征线的强度和轮廓有所不同。早期的光谱显示出Ca ii H&K双重态和NIR三重态中强烈的高速（HV）特征，它们明显地以20，000 ~ 25，000 km s−1的速度从光球层（v = 10，000 km s − 1）分离。一个有趣的特征是在最早的光谱中观察到的6000 nm附近的平底吸收，它迅速演变成三角形，然后在最大亮度前一周左右变成正常的Si ii λ6355吸收轮廓。这种前极大光谱演化可能是由于光球速度下的Si iiλ6355和另一个HV吸收分量（例如，一个Si ii壳层，速度为18，000 km s−1），可能在其他正常的Ia超新星中很常见。的HV吸收功能的可能起源进行了简要讨论。

We present extensive photometry at ultraviolet (UV), optical, and near-infrared (NIR) wavelengths, as well as dense sampling of optical spectra, for the normal Type Ia supernova (SN Ia) 2005cf. The optical photometry, performed at eight different telescopes, shows a 1σ scatter of ≲0.03 mag after proper corrections for the instrument responses. From the well-sampled light curves, we find that SN 2005cf reached a B-band maximum at 13.63 ± 0.02 mag, with an observed luminosity decline rate Δm15(B) = 1.05 ± 0.03 mag. The correlations between the decline rate and various color indexes, recalibrated on the basis of an expanded SN Ia sample, yield a consistent estimate for the host-galaxy reddening of SN 2005cf, E(B − V)host = 0.10 ± 0.03 mag. The UV photometry was obtained with the Hubble Space Telescope and the Swift Ultraviolet/Optical Telescope, and the results match each other to within 0.1–0.2 mag. The UV light curves show similar evolution to the broadband U, with an exception in the 2000–2500 Å spectral range (corresponding to the F220W/uvm2 filters), where the light curve appears broader and much fainter than that on either side (likely owing to the intrinsic spectral evolution). Combining the UV data with the ground-based optical and NIR data, we establish the generic UV-optical-NIR bolometric light curve for SN 2005cf and derive the bolometric corrections in the absence of UV and/or NIR data. The overall spectral evolution of SN 2005cf is similar to that of a normal SN Ia, but with variety in the strength and profile of the main feature lines. The spectra at early times displayed strong, high-velocity (HV) features in the Ca ii H&K doublet and NIR triplet, which were distinctly detached from the photosphere (v ≈ 10,000 km s−1) at a velocity ranging from 20,000 to 25,000 km s−1. One interesting feature is the flat-bottomed absorption observed near 6000 Å in the earliest spectrum, which rapidly evolved into a triangular shape and then became a normal Si ii λ6355 absorption profile at about one week before maximum brightness. This premaximum spectral evolution is perhaps due to the blending of the Si iiλ6355 at photospheric velocity and another HV absorption component (e.g., an Si ii shell at a velocity ∼18,000 km s−1) in the outer ejecta, and may be common in other normal SNe Ia. The possible origin of the HV absorption features is briefly discussed.

THE GOLDEN STANDARD TYPE Ia SUPERNOVA 2005cf: OBSERVATIONS FROM THE ULTRAVIOLET TO THE NEAR-INFRARED WAVEBANDS

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