The Astrophysical Journal (Jan 2025)
Detection of an Orphan X-Ray Flare from a Blazar Candidate EP240709a with the Einstein Probe
- Mingjun Liu,
- Yijia Zhang,
- Yun Wang,
- Rui Xue,
- David Buckley,
- D. Andrew Howell,
- Chichuan Jin,
- Wenxiong Li,
- Itumeleng Monageng,
- Haiwu Pan,
- Ning-Chen Sun,
- Samaporn Tinyanont,
- Lingzhi Wang,
- Weimin Yuan,
- Jie An,
- Moira Andrews,
- Rungrit Anutarawiramkul,
- Pathompong Butpan,
- Yong Chen,
- Huaqing Cheng,
- Weiwei Cui,
- Cui-Yuan Dai,
- Lixin Dai,
- Joseph Farah,
- Hua Feng,
- Shaoyu Fu,
- Zhen Guo,
- Shumei Jia,
- Shuaiqing Jiang,
- An Li,
- Chengkui Li,
- Dongyue Li,
- Tianying Lian,
- Yifang Liang,
- Heyang Liu,
- Xing Liu,
- Yuan Liu,
- Jirong Mao,
- Curtis McCully,
- Megan Newsome,
- Estefania Padilla Gonzalez,
- Xin Pan,
- Xinxiang Sun,
- Giacomo Terreran,
- Ze-Rui Wang,
- Qinyu Wu,
- Hubing Xiao,
- Dingrong Xiong,
- Dong Xu,
- Xinpeng Xu,
- Suijian Xue,
- Haonan Yang,
- Jun Yang,
- Jin Zhang,
- Wenda Zhang,
- Wenjie Zhang,
- Hu Zou
Affiliations
- Mingjun Liu
- ORCiD
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- Yijia Zhang
- Department of Astronomy, Tsinghua University , Beijing 100084, People’s Republic of China
- Yun Wang
- ORCiD
- Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences , Nanjing 210034, People’s Republic of China
- Rui Xue
- ORCiD
- Department of Physics, Zhejiang Normal University , Jinhua 321004, People’s Republic of China
- David Buckley
- ORCiD
- South African Astronomical Observatory , Cape Town 7935, South Africa; Department of Astronomy, University of Cape Town , Rondebosch 7701, South Africa; Department of Physics, University of the Free State , Bloemfontein 9300, South Africa
- D. Andrew Howell
- ORCiD
- Las Cumbres Observatory , 6740 Cortona Drive, Suite 102, Goleta, CA 93117-5575, USA; Department of Physics, University of California , Santa Barbara, CA 93106-9530, USA
- Chichuan Jin
- ORCiD
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- Wenxiong Li
- ORCiD
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]
- Itumeleng Monageng
- ORCiD
- South African Astronomical Observatory , Cape Town 7935, South Africa; Department of Astronomy, University of Cape Town , Rondebosch 7701, South Africa
- Haiwu Pan
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- Ning-Chen Sun
- ORCiD
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China; Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University , Beijing 102206, People’s Republic of China
- Samaporn Tinyanont
- ORCiD
- National Astronomical Research Institute of Thailand , 260 Moo 4, Donkaew, Maerim, Chiang Mai 50180, Thailand
- Lingzhi Wang
- ORCiD
- Chinese Academy of Sciences, South America Center for Astronomy (CASSACA) , National Astronomical Observatories, Chinese Academy of Sciences, Beijing, People’s Republic of China; CAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing, People’s Republic of China
- Weimin Yuan
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- Jie An
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- Moira Andrews
- ORCiD
- Las Cumbres Observatory , 6740 Cortona Drive, Suite 102, Goleta, CA 93117-5575, USA
- Rungrit Anutarawiramkul
- National Astronomical Research Institute of Thailand , 260 Moo 4, Donkaew, Maerim, Chiang Mai 50180, Thailand
- Pathompong Butpan
- National Astronomical Research Institute of Thailand , 260 Moo 4, Donkaew, Maerim, Chiang Mai 50180, Thailand
- Yong Chen
- ORCiD
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics , Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
- Huaqing Cheng
- ORCiD
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]
- Weiwei Cui
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics , Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
- Cui-Yuan Dai
- ORCiD
- School of Astronomy and Space Science, Nanjing University , Nanjing 210023, People’s Republic of China; Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University) , Ministry of Education, Nanjing 210023, People’s Republic of China
- Lixin Dai
- ORCiD
- Department of Physics, University of Hong Kong , Pokfulam Road, Hong Kong, People’s Republic of China
- Joseph Farah
- ORCiD
- Department of Physics, University of California , Santa Barbara, CA 93106-9530, USA; Las Cumbres Observatory , 6740 Cortona Drive, Suite 102, Goleta, CA 93117-557, USA
- Hua Feng
- ORCiD
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics , Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
- Shaoyu Fu
- ORCiD
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- Zhen Guo
- Instituto de Física y Astronomía, Universidad de Valparaíso , avenida Gran Bretaña, 1111, Casilla 5030, Valparaíso, Chile; Millennium Institute of Astrophysics , Nuncio Monseñor Sotero Sanz 100, Of. 104, Providencia, Santiago, Chile
- Shumei Jia
- ORCiD
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics , Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
- Shuaiqing Jiang
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- An Li
- ORCiD
- Institute for Frontier in Astronomy and Astrophysics, Beijing Normal University , Beijing 102206, People’s Republic of China; Department of Astronomy, Beijing Normal University , Beijing 100875, People’s Republic of China
- Chengkui Li
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics , Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
- Dongyue Li
- ORCiD
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]
- Tianying Lian
- ORCiD
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- Yifang Liang
- ORCiD
- Purple Mountain Observatory, Chinese Academy of Sciences , Nanjing 210023, People’s Republic of China; School of Astronomy and Space Sciences, University of Science and Technology of China , Hefei 230026, People’s Republic of China
- Heyang Liu
- ORCiD
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]
- Xing Liu
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- Yuan Liu
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- Jirong Mao
- ORCiD
- Yunnan Observatories, Chinese Academy of Sciences , 396 Yangfangwang, Guandu District, Kunming 650216, People’s Republic of China ; [email protected]; Center for Astronomical Mega-Science , Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012, People’s Republic of China; Key Laboratory for the Structure and Evolution of Celestial Objects , Chinese Academy of Sciences, 396 Yangfangwang, Guandu District, Kunming 650216, People’s Republic of China
- Curtis McCully
- ORCiD
- Las Cumbres Observatory , 6740 Cortona Drive, Suite 102, Goleta, CA 93117-5575, USA; Department of Physics, University of California , Santa Barbara, CA 93106-9530, USA
- Megan Newsome
- ORCiD
- Las Cumbres Observatory , 6740 Cortona Drive, Suite 102, Goleta, CA 93117-5575, USA; Department of Physics, University of California , Santa Barbara, CA 93106-9530, USA
- Estefania Padilla Gonzalez
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Xin Pan
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]
- Xinxiang Sun
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- Giacomo Terreran
- ORCiD
- Adler Planetarium , 1300 S DuSable Lake Shore Drive, Chicago, IL 60605, USA
- Ze-Rui Wang
- ORCiD
- College of Physics and Electronic Engineering, Qilu Normal University , Jinan 250200, People’s Republic of China
- Qinyu Wu
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- Hubing Xiao
- ORCiD
- Shanghai Key Lab for Astrophysics, Shanghai Normal University , Shanghai 200234, People’s Republic of China
- Dingrong Xiong
- ORCiD
- Yunnan Observatories, Chinese Academy of Sciences , 396 Yangfangwang, Guandu District, Kunming 650216, People’s Republic of China ; [email protected]; Center for Astronomical Mega-Science , Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012, People’s Republic of China; Key Laboratory for the Structure and Evolution of Celestial Objects , Chinese Academy of Sciences, 396 Yangfangwang, Guandu District, Kunming 650216, People’s Republic of China
- Dong Xu
- ORCiD
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- Xinpeng Xu
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- Suijian Xue
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]
- Haonan Yang
- ORCiD
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China; Max-Planck-Institut für extraterrestrische Physik , Gießenbachstraße 1, D-85748 Garching bei München, Germany
- Jun Yang
- ORCiD
- School of Astronomy and Space Science, Nanjing University , Nanjing 210023, People’s Republic of China; Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University) , Ministry of Education, Nanjing 210023, People’s Republic of China
- Jin Zhang
- ORCiD
- School of Physics, Beijing Institute of Technology , Beijing 100081, People’s Republic of China
- Wenda Zhang
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]; School of Astronomy and Space Science, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People’s Republic of China
- Wenjie Zhang
- ORCiD
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]
- Hu Zou
- ORCiD
- National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Beijing 100101, People’s Republic of China ; [email protected]
- DOI
- https://doi.org/10.3847/1538-4357/adc301
- Journal volume & issue
-
Vol. 984,
no. 1
p. 5
Abstract
Blazars are often observed to flare across multiple wavelengths. Orphan flares from blazars have only been detected a few times, providing an opportunity to understand the structure of the jet in the accreting system. We report a remarkable orphan X-ray flare from a blazar candidate EP240709a, detected by the Einstein Probe (EP) in July 2024. The multiband spectral properties and variability support EP240709a as a high-energy peaked BL Lacertae-type object. The flux in 0.5–10 keV increased by at least 28 times to the value of low state in 2020, with no significant flaring detected in other bands during the same period. EP240709a exhibits the harder-when-brighter tendency in the X-ray band during the orphan flare, while its infrared-optical spectra are featureless. We employ one-zone and two-zone leptonic synchrotron self-Compton models to perform the spectral energy distribution fitting. Detecting this rare orphan flare shows the potential of EP in discovering peculiar activities from AGN in high-cadence X-ray sky surveys.
Keywords
