High‐speed, multicolour optical photometry of the anomalous X‐ray pulsar 4U 0142+61 with ULTRACAM
High‐speed, multicolour optical photometry of the anomalous X‐ray pulsar 4U 0142+61 with ULTRACAM
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使用 ULTRACAM 对异常 X 射线脉冲星 4U 0142+61 进行高速多色光学光度测量
DOI：
10.1111/j.1365-2966.2005.09465.x
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发表时间：
2005
影响因子：
4.8
通讯作者：
V. Kaspi
中科院分区：
文献类型：
--
作者：
V. Dhillon;T. Marsh;F. Hulleman;M. Kerkwijk;A. Shearer;S. Littlefair;F. Gavriil;V. Kaspi
本文介绍了反常X射线脉冲星的高速多色光学测光
4U 0142 + 61，由4.2米威廉·赫歇尔望远镜上的ULTRACAM拍摄。我们
在i = 23.7 ± 0.1，g = 27.2 ± 0.2和u> 25.8的星等处检测到4U 0142 + 61，与Hulleman等人最近发现的星等一致，因此证实了它们的存在。
发现了光学中的光谱断裂和缺乏长期光学可变性。我们
这也证实了克恩和马丁早期的发现，即4U 0142 + 61显示了光学脉动
与X射线脉冲的周期相同（约8.7秒）。我们数据中的均方根脉冲分数为
29 ± 8%，比0.2 - 8 keV X射线均方根脉冲部分大5 - 7倍。光学
和X射线脉冲轮廓显示出相似的形态，似乎是近似同相的
前者仅滞后后者0.04 ± 0.02周。结合
由于X射线观测的限制，这里给出的结果有利于磁星
对异常X射线光谱的解释。
We present high-speed, multicolour optical photometry of the anomalous X-ray pulsar
4U 0142+61, obtained with ULTRACAM on the 4.2-m William Herschel Telescope. We
detect 4U 0142+61 at magnitudes of i� = 23.7 ± 0.1, g� = 27.2 ± 0.2 and u� > 25.8, consistent with the magnitudes found recently by Hulleman et al. and hence confirming their
discovery of both a spectral break in the optical and a lack of long-term optical variability. We
also confirm the earlier discovery of Kern & Martin that 4U 0142+61 shows optical pulsations
with an identical period (∼8.7 s) to the X-ray pulsations. The rms pulsed fraction in our data is
29 ± 8 per cent, 5–7 times greater than the 0.2–8 keV X-ray rms pulsed fraction. The optical
and X-ray pulse profiles show similar morphologies and appear to be approximately in phase
with each other, the former lagging the latter by only 0.04 ± 0.02 cycles. In conjunction with
the constraints imposed by X-ray observations, the results presented here favour a magnetar
interpretation for the anomalous X-ray pulsars.