INTEGRAL observations of the blazar Mrk 421 in outburst Results of a multi-wavelength campaign
INTEGRAL observations of the blazar Mrk 421 in outburst Results of a multi-wavelength campaign
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爆发中的耀变体 Mrk 421 的整体观测 多波长活动的结果
DOI：
10.1051/0004-6361:20079199
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发表时间：
2008
影响因子：
6.5
通讯作者：
M. Tornikoski
中科院分区：
文献类型：
--
作者：
G. Lichti;E. Bottacini;M. Ajello;P. Charlot;W. Collmar;A. Falcone;D. Horan;S. Huber;A. Kienlin;A. Lähteenmäki;E. Lindfors;D. Morris;K. Nilsson;D. Petry;M. Rüger;A. Sillanpää;F. Spanier;M. Tornikoski
上下文如果想要了解耀变体的物理学，在所有波长上更好的同步观测是很重要的，所以幸运的是，在2006年6月，通过将RXTE计数率增加到30 mCrab以上，可以触发对TeV发射耀变体Mrk 421的Too观测。然后用除光谱仪SPI外的所有INTEGRAL仪器观察该源，总曝光量为829 ks。在此期间，IBIS和JEM-X观测到了几次爆发.多波长观测立即被触发，并在高达TeV能量的无线电、光学和X射线波长处观测到了该源。目标。在这些观测过程中获得的数据进行了分析的时间变异性，时间滞后，相关的变异性，和光谱的演变，然后汇编在aF谱。方法.用通常的相关和时间分析方法分析了不同仪器/望远镜的观测结果。用XSPEC对X射线数据进行了光谱分析。结果观测到四个在X射线下的强烈耀斑，这些耀斑在其他波长下看不到（部分原因是数据丢失）。从X射线的最快上升，可以推导出发射区域延伸的上限。高能和低能X射线之间的时间差被观察到，这使得磁场强度的估计。对X射线的光谱分析表明，低能（3 - 143keV）光谱指数有轻微的光谱硬化。Swift-XRT（0.2 - 10 keV）数据的硬度比分析表明与强度的小相关性;例如，观察到硬到软的演变。在IBIS/ISGRI的能量（20 - 150 keV）下，这种相关性不太明显。一个多波长的光谱组成和X射线和辐射热光度计算。结论.观测到的Mrk421的耀斑活动主要在X射线下可见。发现光谱随强度的变化很小。但至少有一个耀斑表现出与其他耀斑完全不同的光谱行为，因此可以得出结论，每个相对论运动电子团都有自己的物理环境，从而导致不同的发射特征。从轻子发射模型对数据的拟合中，我们发现观测到的变化可能是由于粒子加速效率的变化。
Context. If one wants to understand the physics of blazars, better simultaneous observations are important at all wavelengths, so it was fortunate that a ToO observation of the TeV-emitting blazar Mrk 421 with INTEGRAL could be triggered in June 2006 by an increase in the RXTE count rate to more than 30 mCrab. The source was then observed with all INTEGRAL instruments, with the exception of the spectrometer SPI, for a total exposure of 829 ks. During this time several outbursts were observed by IBIS and JEM- X. Multiwavelength observations were immediately triggered, and the source was observed at radio, optical, and X-ray wavelengths up to TeV energies. Aims. The data obtained during these observations were analysed with respect to time variability, time lags, correlated vari ability, and spectral evolution and then compiled in aFspectrum. Methods. The observations of the different instruments/telescopes were analysed with the usual correlation and time-analysis methods. The spectral analysis of the X-ray data was performed with XSPEC. Results. Four strong flares at X-rays were observed that were not seen a t other wavelengths (partially because of missing data). From the fastest rise in the X-rays, an upper limit could be derived to the extension of the emission region. A time lag between high-energy and low-energy X-rays was observed, which allowed an estimation of the magnetic-field strength. The spectr al analysis of the X-rays revealed a slight spectral hardening of the low-energy (3-∼43 keV) spectral index. The hardness-ratio analysis of the Swift-XRT (0.2 - 10 keV) data indicated a small correlation with the intensity; i. e., a hard-to-soft evolution was obser ved. At the energies of IBIS/ISGRI (20 - 150 keV), such correlations are less obvious. A multiwavelength spectrum was composed and the X-ray and bolometric luminosities calculated. Conclusions. The observed flaring activity of Mrk 421 is mainly visible at X -rays. It is found that the spectral change with intensity is small. But at least one flare showed a completely di fferent spectral behaviour than the other flares, so one can con clude that each blob of relativistic-moving electrons has its own individu al physical environment that leads to different emission characteristics. From a fit of a leptonic emission model to the data, one finds that the observed variability may be due to a varying effi ciency of particle acceleration.
影响因子：
4.9
作者：
Gehrels, N;Chincarini, G;Zhang, WW
通讯作者：
Zhang, WW