Back to Business: SLX 1746-331 after 13 Years of Silence

Authors：Peng, Jing-Qiang^*; Zhang, Shu; Wang, Peng-Ju; Zhang, Shuang-Nan; Kong, Ling-Da; Chen, Yu-Peng; Shui, Qing-Cang; Ji, Long; Qu, Jin-Lu; Tao, Lian; Ge, Ming-Yu; Ma, Rui-Can; Chang, Zhi; Li, Jian; Li, Zhao-sheng; Yu, Zhuo-Li; Yan, Zhe; Zhang, Peng; Xiao, Yun-Xiang; Zhao, Shu-Jie

Source：Astrophysical Journal, 2023, 955(2): 96.

DOI：10.3847/1538-4357/acf461

• BLACK-HOLE CANDIDATES
• GALACTIC PLANE SURVEY
• GX 339-4
• STATE TRANSITION
• ACCRETION DISK
• MAXI J1348-630
• LOW/HARD STATE
• XMM-NEWTON
• X-RAYS
• MASS

The black hole candidate system SLX 1746-331 was back to business in 2023, after a long silence of roughly 13 years. An outburst was observed thoroughly by Insight-HXMT and NICER. The outburst is characterized by spectral dominance of the soft state, where the joint Insight-HXMT and NICER spectral analysis shows the temperature dependence of the disk flux follows Tin3.98 , and thus suggests that the inner disk reaches its innermost stable circular orbit during almost the entire outburst. By assuming 0.3 L Edd for the peak flux and an inclination angle of zero degrees, the lower limit of the compact object hosted in this system is estimated as 3.28 & PLUSMN; 2.14 M & ODOT;. We also look into the relation between the disk temperature and disk flux for a sample of black hole systems, and by taking the disk temperature derived in the outburst of SLX 1746-331, such a relation results in a mass estimation of 5.2 & PLUSMN; 4.5 M & ODOT;. Finally, the spin of the compact object is constrained to be larger than 0.8 with the spectral model KERRBB.

• Institution
  湘潭大学; 中国科学院研究生院; 1; 中山大学