Energy-dependent intensity variation of the persistent X-ray emission of magnetars observed with Suzaku

被引：1
作者：
Nakagawa, Yujin [1 ]
Ebisawa, Ken [2 ]
Enoto, Teruaki [3 ]
机构：
[1] Japan Agcy Marine Earth Sci & Technol, Ctr Earth Informat Sci & Technol, Kanazawa Ku, 3173-25 Showa Machi, Yokohama, Kanagawa 2360001, Japan
[2] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Chuo Ku, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 2525210, Japan
[3] Kyoto Univ, Hakubi Ctr, Sakyo Ku, Yoshida Ushinomiya Cho, Kyoto, Kyoto 6068501, Japan
来源：
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN | 2018年 / 70卷 / 02期
关键词：
pulsars: general; stars: magnetars; X-rays: stars; SOFT GAMMA-REPEATERS; MAGNETIZED NEUTRON-STARS; SGR 0501+4516; SHORT BURSTS; 1E; 1547.0-5408; BOARD SUZAKU; BROAD-BAND; DISCOVERY; OUTBURST; SPECTRA;
D O I：
10.1093/pasj/psy013
中图分类号：
P1 [天文学];
学科分类号：
0704 ;
摘要：
The emission mechanism of magnetars is still controversial even though various observational and theoretical studies have been made. In order to investigate mechanisms of both the persistent X-ray emission and the burst emission of the magnetars, we propose a model in which the persistent X-ray emission consists of numerous micro-bursts of various sizes. If this model is correct, root mean square (rms) intensity variations of the persistent emission would exceed the values expected from the Poisson distribution. Using Suzaku archive data of 11 magnetars (22 observations), the rms intensity variations were calculated from 0.2 keV to 70 keV. As a result, we found significant excess rms intensity variations from all 11 magnetars. We suppose that numerous micro-bursts constituting the persistent X-ray emission cause the observed variations, suggesting that the persistent X-ray emission and the burst emission have identical emission mechanisms. In addition, we found that the rms intensity variations clearly increase toward higher energy bands for four magnetars (six observations). The energy-dependent rms intensity variations imply that the soft thermal component and the hard X-ray component are emitted from different regions far apart from each other.
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页数：10
相关论文
共 33 条
[1]   Resonant compton upscattering in Anomalous X-ray Pulsars [J].
Baring, Matthew G. ;
Harding, Alice K. .
ASTROPHYSICS AND SPACE SCIENCE, 2007, 308 (1-4) :109-118
[2]   Magnetar corona [J].
Beloborodov, A. M. ;
Thompson, C. .
ASTROPHYSICS AND SPACE SCIENCE, 2007, 308 (1-4) :631-639
[3]   FORMATION OF VERY STRONGLY MAGNETIZED NEUTRON-STARS - IMPLICATIONS FOR GAMMA-RAY BURSTS [J].
DUNCAN, RC ;
THOMPSON, C .
ASTROPHYSICAL JOURNAL, 1992, 392 (01) :L9-L13
[4]   Spectral comparison of weak short bursts to the persistent X-rays from the magnetar 1E 1547.0-5408 in its 2009 outburst [J].
Enoto, T. ;
Nakagawa, Y. E. ;
Sakamoto, T. ;
Makishima, K. .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2012, 427 (04) :2824-2840
[5]   BROADBAND STUDY WITH SUZAKU OF THE MAGNETAR CLASS [J].
Enoto, T. ;
Nakazawa, K. ;
Makishima, K. ;
Rea, N. ;
Hurley, K. ;
Shibata, S. .
ASTROPHYSICAL JOURNAL LETTERS, 2010, 722 (02) :L162-L167
[6]   WIDE-BAND SUZAKU ANALYSIS OF THE PERSISTENT EMISSION FROM SGR 0501+4516 DURING THE 2008 OUTBURST [J].
Enoto, T. ;
Rea, N. ;
Nakagawa, Y. E. ;
Makishima, K. ;
Sakamoto, T. ;
Esposito, P. ;
Goetz, D. ;
Hurley, K. ;
Israel, G. L. ;
Kokubun, M. ;
Mereghetti, S. ;
Murakami, H. ;
Nakazawa, K. ;
Stella, L. ;
Tiengo, A. ;
Turolla, R. ;
Yamada, S. ;
Yamaoka, K. ;
Yoshida, A. ;
Zane, S. .
ASTROPHYSICAL JOURNAL, 2010, 715 (01) :665-670
[7]   Magnetar Broadband X-Ray Spectra Correlated with Magnetic Fields: Suzaku Archive of SGRs and AXPs Combined with NuSTAR, Swift, and RXTE [J].
Enoto, Teruaki ;
Shibata, Shinpei ;
Kitaguchi, Takao ;
Suwa, Yudai ;
Uchide, Takahiko ;
Nishioka, Hiroyuki ;
Kisaka, Shota ;
Nakano, Toshio ;
Murakami, Hiroaki ;
Makishima, Kazuo .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 2017, 231 (01)
[8]   Suzaku Discovery of a Hard X-Ray Tail in the Persistent Spectra from the Magnetar 1E 1547.0-5408 during its 2009 Activity [J].
Enoto, Teruaki ;
Nakazawa, Kazuhiro ;
Makishima, Kazuo ;
Nakagawa, Yujin E. ;
Sakamoto, Takanori ;
Ohno, Masanori ;
Takahashi, Tadayuki ;
Terada, Yukikatsu ;
Yamaoka, Kazutaka ;
Murakami, Toshio ;
Takahashi, Hiromitsu .
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 2010, 62 (02) :475-485
[9]   SGR 1806-20 about two years after the giant flare:: Suzaku, XMM-Newton and INTEGRAL observations [J].
Esposito, P. ;
Mereghetti, S. ;
Tiengo, A. ;
Zane, S. ;
Turolla, R. ;
Goetz, D. ;
Rea, N. ;
Kawai, N. ;
Ueno, M. ;
Israel, G. L. ;
Stella, L. ;
Feroci, M. .
ASTRONOMY & ASTROPHYSICS, 2007, 476 (01) :321-330
[10]  
Ferandez R., 2007, APJ, V660, P615
1234