AGN STORM 2. III. A NICER View of the Variable X-Ray Obscurer in Mrk 817-猫眼课题宝

DOI：

10.3847/1538-4357/acbf44

发表时间：

2023-02

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：

E. Partington;E. Cackett;E. Kara;G. Kriss;A. Barth;G. D. Rosa;Y. Homayouni;K. Horne;H. Landt;A. Zoghbi;R. Edelson;N. Arav;Benjamin D. Boizelle;M. Bentz;M. Brotherton;D. Byun;E. Bontà;M. Dehghanian;P. Du;C. Fian;A. Filippenko;J. Gelbord;M. Goad;D. G. Buitrago;C. Grier;P. Hall;Chen Hu;D. Ilić;M. D. Joner;Shai Kaspi Christopher S. Kochanek;K. Korista;A. Kovačević;D. Kynoch;J. McLane;M. Mehdipour;Jake A. Miller Christos Panagiotou;R. Plesha;L. Popović;D. Proga;D. Rogantini;T. Storchi-Bergmann;D. Sanmartim;M. Siebert;M. Vestergaard;Martin P. Ward;T. Waters;F. Zaidouni

AGN STORM 2合作项目针对Seyfert 1星系Mrk 817进行了为期一年的多波长协调混响测绘活动，包括哈勃太空望远镜，Swift，XMM-牛顿，NICER和地面观测站。NICER和XMM的早期观测显示，X射线状态比历史观测暗10倍，与新的无尘电离遮蔽物的存在一致。下面对NICER光谱的分析将观测到的X射线通量的可变性归因于遮蔽物的柱密度的变化至少一个数量级（NH范围从2.85−0.33+0.48× 1022 cm −2到25.6−3.5+3.0× 1022 cm −2）和固有连续亮度（未遮蔽的通量范围为10−11.8至10−10.5 erg s−1 cm−2）。虽然X射线通量通常保持在微弱的状态，但有一次大耀斑期间，Mrk 817恢复到其历史平均通量。在耀斑期间，遮蔽气体仍然以较低的柱密度存在，但它也变得高度电离，增加了其透明度。X射线遮蔽物的柱密度和紫外线宽吸收线的强度之间的相关性表明，X射线和紫外线连续都受到相同的遮蔽作用，与从内部宽线区域发射的cloudspeaker盘风一致。

The AGN STORM 2 Collaboration targeted the Seyfert 1 galaxy Mrk 817 for a year-long multiwavelength, coordinated reverberation mapping campaign including Hubble Space Telescope, Swift, XMM-Newton, NICER, and ground-based observatories. Early observations with NICER and XMM revealed an X-ray state 10 times fainter than historical observations, consistent with the presence of a new dust-free, ionized obscurer. The following analysis of NICER spectra attributes variability in the observed X-ray flux to changes in both the column density of the obscurer by at least one order of magnitude (N H ranges from 2.85−0.33+0.48×1022cm−2 to 25.6−3.5+3.0×1022cm−2 ) and the intrinsic continuum brightness (the unobscured flux ranges from 10−11.8 to 10−10.5 erg s−1 cm−2). While the X-ray flux generally remains in a faint state, there is one large flare during which Mrk 817 returns to its historical mean flux. The obscuring gas is still present at lower column density during the flare, but it also becomes highly ionized, increasing its transparency. Correlation between the column density of the X-ray obscurer and the strength of UV broad absorption lines suggests that the X-ray and UV continua are both affected by the same obscuration, consistent with a clumpy disk wind launched from the inner broad-line region.

AGN STORM 2. III. A NICER View of the Variable X-Ray Obscurer in Mrk 817

文献摘要

被引文献

相似文献