SDSS J124602.54 + 011318.8: A Highly Luminous Optical Transient at z = 0.385
SDSS J124602.54 + 011318.8: A Highly Luminous Optical Transient at z = 0.385
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SDSS J124602.54 011318.8：z = 0.385 时的高发光光学瞬变
DOI：
10.1086/341887
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
B. Yanny
中科院分区：
文献类型：
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作者：
D. V. vanden Berk;Brian C. Lee;B. Wilhite;J. Beacom;D. Lamb;J. Annis;K. Abazajian;T. Mckay;R. Kron;S. Kent;K. Hurley;R. Kehoe;J. Wren;A. Henden;D. York;D. Schneider;Jennifer K. Adelman;J. Brinkmann;R. Brunner;I. Csabai;M. Harvanek;G. Hennessy;Ž. Ivezić;A. Kleinman;S. Kleinman;J. Krzesinski;D. Long;E. Neilsen;P. Newman;S. Snedden;C. Stoughton;D. Tucker;B. Yanny
我们报告发现了一个高亮度的光学瞬变（OT），SDSS J124602.54 + 011318.8，与一个星系的红移为0.385。在本文中，我们考虑的可能性，OT可能是一个伽玛射线暴（GRB）余辉。作为斯隆数字巡天（SDSS）正常操作的一部分，获得了三组图像和两组光谱。在前两组图像中，相隔两个晚上观察到的物体显示为r* 17的点源。第三组图像是在大约410天后观测到的，显示了一个扩展的源，比第一组图像暗2.5 mags。这些光谱是在前两组图像之后大约400天和670天观测到的，两者都显示出一个红移为0.385的明显正常星系。将OT与星系联系起来，绝对星等为M =-24.8，比有史以来测量到的最明亮的超新星亮4等。由前两组图像得到的扣除星系的OT的光谱能量分布与大多数GRB余辉相似，分别符合单次幂定律，指数分别为βν = -0.92和-1.29。根据OT的光度、同期ROTSE I图像中的未检测和光谱斜率的变化，OT如果是余辉，可能是在平台期或缓慢衰落阶段早期发现的。在SDSS的这个阶段发现的GRB余辉与预期一致，但只有当光学发射比伽马射线弱得多时。我们强调，不能排除OT的其他解释; Gal-Yam等人（2002）最近的一项后续研究提供了强有力的证据，证明这个来源实际上是一个不寻常的活动星系核（AGN）。
We report the discovery of a highly luminous optical transient (OT), SDSS J124602.54 + 011318.8, associated with a galaxy at a redshift of 0.385. In this paper, we consider the possibility that the OT may be a gamma-ray burst (GRB) afterglow. Three sets of images and two sets of spectra were obtained as part of the normal operations of the Sloan Digital Sky Survey (SDSS). In the first two image sets, observed two nights apart, the object appears as a point source at r* ≈ 17. The third image set, observed about 410 days later, shows an extended source which is more than 2.5 mags fainter. The spectra were observed about 400 and 670 days after the first two image sets, and both show an apparently normal galaxy at a redshift of 0.385. Associating the OT with the galaxy, the absolute magnitude was M = -24.8, which is over 4 mag brighter than the most luminous supernova ever measured. The spectral energy distributions of the galaxy-subtracted OT derived from the first two image sets are well-fitted by single power laws with indices of βν = -0.92 and -1.29, respectively, similar to most GRB afterglows. Based upon the luminosity of the OT, nondetections in contemporaneous ROTSE I images and the change in spectral slope, the OT, if an afterglow, was likely discovered early during a plateau or slowly fading phase. The discovery of a GRB afterglow at this stage of the SDSS is consistent with expectations, but only if the optical emission is much less strongly beamed than the gamma rays. We emphasize that other explanations for the OT cannot be ruled out; a recent follow-up study by Gal-Yam et al. (2002) provides strong evidence that this source is in fact an unusual active galactic nucleus (AGN).