Highly Variable Active Galactic Nuclei in the SRG/eROSITA Sky Survey: I. The Constriction of a Sample and the Catalog of Objects Detected in a Low State

Cover Page

Cite item

Full Text

Open Access Open Access
Restricted Access Access granted
Restricted Access Subscription Access

Abstract

We present the results of our search for highly variable active galactic nuclei (AGNs) the X-ray flux from which changed by more than an order of magnitude during the SRG/eROSITA all-sky survey. Using the eROSITA data obtained in the period from December 2019 to February 2022, we have found 1325 sources the X-ray flux from which in the 0.3–2.3 keV energy band changed by more than a factor of 10 at a confidence level of at least 99.73
. Of them, 635 objects have been classified as AGNs or AGN candidates. We describe the procedure of searching for highly variable sources and the selection of extragalactic objects among them and describe the statistical properties of the produced catalog. We provide a catalog of 49 sources for which a statistically significant flux in their low state was detected. For the latter we provide their light curves and X-ray spectra and discuss in detail the most interesting of them.

About the authors

P. S. Medvedev

Space Research Institute, Russian Academy of Sciences

Email: tomedvedev@iki.rssi.ru
117997, Moscow, Russia

M. R. Gilfanov

Space Research Institute, Russian Academy of Sciences; Max Planck Institut für Astrophysik

Email: tomedvedev@iki.rssi.ru
117997, Moscow, Russia; Karl-Schwarzschild-Str. 1, Postfach 1317, D-85741, Garching, Germany

S. Yu. Sazonov

Space Research Institute, Russian Academy of Sciences

Email: tomedvedev@iki.rssi.ru
117997, Moscow, Russia

R. A. Sunyaev

Space Research Institute, Russian Academy of Sciences; Max Planck Institut für Astrophysik

Email: tomedvedev@iki.rssi.ru
117997, Moscow, Russia; Karl-Schwarzschild-Str. 1, Postfach 1317, D-85741, Garching, Germany

G. A. Khorunzhev

Space Research Institute, Russian Academy of Sciences

Author for correspondence.
Email: tomedvedev@iki.rssi.ru
117997, Moscow, Russia

References

  1. Андерсон (T.W. Anderson), Ann. Math. Statist. 33, 1148 (1962).
  2. Антонуччи (R. Antonucci), Ann. Rev. Astron. Astrophys. 31, 473 (1993).
  3. Арнауд и др. (K.A. Arnaud), in G.H. Jacoby and J. Barnes (eds.), Astronomical Data Analysis Software and Systems V, Vol. 101 of Astron. Soc. Pacific Conf. Ser., p. 17 (1996).
  4. Ассеф и др. (R.J. Assef, D. Stern, C.S. Kochanek, A.W. Blain, M. Brodwin, M.J.I. Brown, et al.), Astrophys. J. 772, 26 (2013).
  5. Аттли и др. (P. Uttley, I.M. McHardy, and I.E. Papadakis), MNRAS 332, 231 (2002).
  6. Ахумада и др. (R. Ahumada, C.A. Prieto, A. Almeida, F. Anders, S.F. Anderson, B.H. Andrews, et al.), Astrophys. J. Suppl. Ser. 249, 3 (2020).
  7. Беллм и др. (E.C. Bellm, S.R. Kulkarni, M.J. Graham, R. Dekany, R.M. Smith, R. Riddle, et al.), PASP 131, 018002 (2019).
  8. Бруннер и др. (H. Brunner, T. Liu, G. Lamer, A. Georgakakis, A. Merloni, M. Brusa, et al.), Astron. Astrophys. 661, A1 (2022).
  9. Буас и Бержерон (P. Boisse and J. Bergeron), Astron. Astrophys. 192, 1 (1988).
  10. Вагнетти и др. (F. Vagnetti, S. Turriziani, and D. Trevese), Astron. Astrophys. 536, A84 (2011).
  11. Вагнетти и др. (F. Vagnetti, R. Middei, M. Antonucci, M. Paolillo, and R. Serafinelli), Astron. Astrophys. 593, A55 (2016).
  12. Вайт и др. (R.L. White, R.H. Becker, M.D. Gregg, S.A. Laurent-Muehleisen, M.S. Brotherton, C.D. Impey, et al.), Astrophys. J. Suppl. Ser. 126, 133 (2000).
  13. Верон, Гонсалвес и Верон-Сетти (P. Veron, A.C. Goncalves, and M.P. Veron-Cetty), Astron. Astrophys. 319, 52 (1997).
  14. Гибсон, Брант (R.R. Gibson and W. Brandt), Astrophys. J. 746, 54 (2012).
  15. Грэхам и др. (M.J. Graham, S.R. Kulkarni, E.C. Bellm, S.M. Adams, C. Barbarino, N. Blagorodnova, et al.), PASP 131, 078001 (2019).
  16. Гудман, Вир (J. Goodman and J. Weare), Comm. Appl. Math. Comput. Sci. 5, 65 (2010).
  17. Гьюке (J. Geweke), Bayesian Statistic. 4, 641 (1992).
  18. Джомми и др. (P. Giommi, G. Tagliaferri, K. Beuermann, G. Branduardi-Raymont, R. Brissenden, U. Graser, et al.), Astrophys. J. 378, 77 (1991).
  19. Джонес и др. (D.H. Jones, M.A. Read, W. Saunders, M. Colless, T. Jarrett, Q.A. Parker, et al.), MNRAS 399, 683 (2009).
  20. Зау и др. (I. Zaw, Y.-P. Chen, and G.R. Farrar), Astrophys. J. 872, 134 (2019).
  21. Коллаборация Fermi-LAT и др. (The Fermi- LAT collaboration: M. Ajello, L. Baldini, J. Ballet, D. Bastieri, et al.), arXiv e-prints, p. arXiv:2209.12070 (2022).
  22. Коллаборация Fermi и др. (The Fermi-LAT collaboration: M. Ajello, L. Baldini, J. Ballet, D. Bastieri, et al.), arXiv e-prints, p. arXiv:2209.12070 (2022).
  23. Коллаборация Gaia и др. (Gaia Collaboration, A.G.A. Brown, A. Vallenari, T. Prusti, J.H.J. de Bruijne, C. Babusiaux, et al.), Astron. Astrophys. 649, A1 (2021).
  24. Коллаборация Gaia и др. (Gaia Collaboration, C.A.L. Bailer-Jones, D. Teyssier, L. Delchambre, C. Ducourant, D. Garabato, et al.), arXiv e-prints, p. arXiv:2206.05681 (2022).
  25. Коллаборация HI4PI (HI4PI Collaboration, N. Ben Bekhti, L. Flöer, R. Keller, J. Kerp, D. Lenz, et al.), Astron. Astrophys. 594, A116 (2016).
  26. Крамер (H. Cramér), Scandinav. Actuar. J. 1928, 13 (1928).
  27. Креспо и др. (N. Álvarez Crespo, F. Massaro, D. Milisavljevic, M. Landoni, V. Chavushyan, V. Patiño-Álvarez, et al.), Astron. J. 151, 95 (2016).
  28. Кэш (W. Cash), Astrophys. J. 228, 939 (1979).
  29. Лайк и др. (B.W. Lyke, A.N. Higley, J.N. McLane, D.P. Schurhammer, A.D. Myers, A.J. Ross, et al.), Astrophys. J. Suppl. Ser. 250, 8 (2020).
  30. Ланцуизи и др. (G. Lanzuisi, G. Ponti, M. Salvato, G. Hasinger, N. Cappelluti, A. Bongiorno, et al.), Astrophys. J. 781, 105 (2014).
  31. Лиу и др. (H.-Y. Liu, W.-J. Liu, X.-B. Dong, H. Zhou, T. Wang, H. Lu, et al.), Astrophys. J. Suppl. Ser. 243, 21 (2019).
  32. Лоуренс и др (A. Lawrence, M.G. Watson, K.A. Pounds, and M. Elvis), Nature 325, 694 (1987).
  33. Макхарди, Черни (I. McHardy and B. Czerny), Nature 325, 696 (1987).
  34. Марковиц, Эдельсон (A. Markowitz and R. Edelson), Astrophys. J. 617, 939 (2004).
  35. Маски и др. (F.J. Masci, R.R. Laher, B. Rusholme, D.L. Shupe, S. Groom, J. Surace, et al.), PASP 131, 018003 (2019).
  36. Массаро и др. (E. Massaro, P. Giommi, C. Leto, P. Marchegiani, A. Maselli, M. Perri, et al.), Astron. Astrophys. 495, 691 (2009).
  37. Миддей и др. (R. Middei, F. Vagnetti, S. Bianchi, F. La Franca, M. Paolillo, and F. Ursini), Astron. Astrophys. 599, A82 (2017).
  38. Мэтт и др. (G. Matt, M. Guainazzi, and R. Maiolino), MNRAS 342, 422 (2003).
  39. Остерброк (D.E. Osterbrock), Astrophys. J. 215, 733 (1977).
  40. Павлинский и др. (M. Pavlinsky, A. Tkachenko, V. Levin, N. Alexandrovich, V. Arefiev, V. Babyshkin, et al.), Astron. Astrophys. 650, A42 (2021).
  41. Петерсон (B.M. Peterson), in I. Aretxaga, D. Kunth, and R. Mújica (eds.), Adv. Lect. Starburst-AGN, p. 3 (2001).
  42. Предель и др. (P. Predehl, R. Andritschke, V. Arefiev, V. Babyshkin, O. Batanov, W. Becker, et al.), Astron. Astrophys. 647, A1 (2021).
  43. Пучетти и др. (S. Puccetti, A. Comastri, F. Fiore, P. Arévalo, G. Risaliti, F.E. Bauer, et al.), Astrophys. J. 793, 26 (2014).
  44. Райт и др. (E.L. Wright, P.R.M. Eisenhardt, A.K. Mainzer, M.E. Ressler, R.M. Cutri, T. Jarrett, et al.), Astron. J. 140, 1868 (2010).
  45. Ричи и др. (C. Ricci, F.E. Bauer, P. Arevalo, S. Boggs, W.N. Brandt, F.E. Christensen, et al.), Astrophys. J. 820, 5 (2016).
  46. Ричи и др. (C. Ricci, E. Kara, M. Loewenstein, B. Trakhtenbrot, I. Arcavi, R. Remillard, et al.), Astrophys. J. Lett. 898, L1 (2020).
  47. Смит и др. (K.W. Smith, S.J. Smartt, D.R. Young, J.L. Tonry, L. Denneau, H. Flewelling, et al.), PASP 132, 085002 (2020).
  48. Сюняев и др. (R. Sunyaev, V. Arefiev, V. Babyshkin, A. Bogomolov, K. Borisov, M. Buntov, et al.), Astron. Astrophys. 656, A132 (2021).
  49. Тимлин и др. (J.D. Timlin III, W.N. Brandt, S. Zhu, H. Liu, B. Luo, and Q. Ni), MNRAS 498, 4033 (2020).
  50. Тонри и др. (J.L. Tonry, L. Denneau, A.N. Heinze, B. Stalder, K.W. Smith, S.J. Smartt, et al.), PASP 130, 064505 (2018).
  51. Уилмс и др. (J. Wilms, A. Allen, and R. McCray), Astrophys. J. 542, 914 (2000).
  52. Уэйк и др. (D.A. Wake, K. Bundy, A.M. Diamond-Stanic, R. Yan, M.R. Blanton, M.A. Bershady, et al.), Astron. J. 154, 86 (2017).
  53. Флеш (E.W. Flesch), Publications of the Astron. Soc. of Australia 32, e010 (2015).
  54. Флеш (E.W. Flesch), arXiv e-prints, p. arXiv:2105.12985 (2021).
  55. Хинкли (D. V. Hinkley), Biometrika 56, 635 (1969).
  56. Хуо и др. (Z.-Y. Huo, X.-W. Liu, M.-S. Xiang, H.-B. Yuan, Y. Huang, H.-H. Zhang, et al.), Astron. J. 145, 159 (2013).
  57. Шакура, Сюняев (N.I. Shakura and R.A. Sunyaev), Astron. Astrophys. 24, 337 (1973).
  58. Шеммер и др. (O. Shemmer, W.N. Brandt, M. Paolillo, S. Kaspi, C. Vignali, M.S. Stein, et al.), Astrophys. J. 783, 116 (2014).
  59. Шеммер и др. (O. Shemmer, W.N. Brandt, M. Paolillo, S. Kaspi, C. Vignali, P. Lira, et al.), Astrophys. J., 848, 46 (2017).
  60. Штерн и др. (D. Stern, B. McKernan, M.J. Graham, K.E.S. Ford, N.P. Ross, A.M. Meisner, et al.), Astrophys. J. 864, 27 (2018).
  61. Яо и др. (S. Yao, X.-B. Wu, Y.L. Ai, J. Yang, Q. Yang, X. Dong, et al.), Astrophys. J. Suppl. Ser. 240, 6 (2019).

Supplementary files

Supplementary Files
Action
1. JATS XML
Download

Copyright (c) 2023 Pleiades Publishing, Ltd.