Astrophysics and Space Science

, 364:153 | Cite as

Optical spectroscopic classification of 35 hard X-ray sources from the Swift-BAT 70-month catalogue

  • E. J. Marchesini
  • N. Masetti
  • E. Palazzi
  • V. Chavushyan
  • E. Jiménez-Bailón
  • V. M. Patiño-Álvarez
  • V. Reynaldi
  • A. F. Rojas
  • I. Saviane
  • I. Andruchow
  • L. Bassani
  • A. Bazzano
  • A. J. Bird
  • A. Malizia
  • D. Minniti
  • L. Monaco
  • J. B. Stephen
  • P. Ubertini
Original Article


The nature of a substantial percentage (about one fifth) of hard X-ray sources discovered with the BAT instrument onboard the Neil Gehrels Swift Observatory (hereafter Swift) is unknown because of the lack of an identified longer-wavelength counterpart. Without such follow-up, an X-ray catalogue is of limited astrophysical value: we therefore embarked, since 2009, on a long-term project to uncover the optical properties of sources identified by Swift by using a large suite of ground-based telescopes and instruments.

In this work, we continue our programme of characterization of unidentified or poorly studied hard X-ray sources by presenting the results of an optical spectroscopic campaign aimed at pinpointing and classifying the optical counterparts of 35 hard X-ray sources taken from the 70-month BAT catalogue. This sample was selected out of the available information about the chosen objects: either they are completely unidentified sources, or their association with a longer-wavelength counterpart is still ambiguous.

With the use of optical spectra taken at six different telescopes we were able to identify the main spectral characteristics (continuum type, redshift, and emission or absorption lines) of the observed objects, and determined their nature.

We identify and characterize a total of 41 optical candidate counterparts corresponding to 35 hard X-ray sources given that, because of positional uncertainties, multiple lower energy counterparts can sometimes be associated with higher energy detections. We discuss which ones are the actual (or at least most likely) counterparts based on our observational results.

In particular, 31 sources in our sample are active galactic nuclei: 16 are classified as Type 1 (with broad and narrow emission lines) and 13 are classified as Type 2 (with narrow emission lines only); two more are BL Lac-type objects. We also identify one LINER, one starburst, and 3 elliptical galaxies. The remaining 5 objects are galactic sources: we identify 4 of them as cataclysmic variables, whereas one is a low mass X-ray binary.


Galaxies: Seyfert Quasars: emission lines BL Lacertae objects: general X-rays: binaries Stars: novae, cataclysmic variables X-rays: individuals 



We thank Silvia Galleti for Service Mode observations at the Loiano telescope, and Roberto Gualandi, Ivan Bruni and Antonio De Blasi for night assistance; we also thank Walter Boschin for coordinating our Service Mode observations at the TNG, and Janet Torrealba, Héctor Otí-Floranes and Felipe Ramón-Fox for observations at SPM. This research has made use of the ASI Space Science Data Center Multimission Archive; it also used the NASA Astrophysics Data System Abstract Service, the NASA/IPAC Extragalactic Database (NED), and the NASA/IPAC Infrared Science Archive, which are operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This publication made use of data products from the Two Micron All Sky Survey (2MASS), which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. This research has also made use of data extracted from the Six-degree Field Galaxy Survey archive, of the SIMBAD and VIZIER databases operated at CDS, Strasbourg, France, and of the HyperLeda catalogue operated at the Observatoire de Lyon, France. V.C. and V.M.P.A. acknowledge support from CONACyT research grant No. 280789. The data used in this paper were partially based upon observations carried out at the Observatorio Astronómico Nacional on the Sierra San Pedro Mártir (OAN-SPM) and Observatorio Astrofísico Guillermo Haro (OAGH) in Sonora, Mexico.


  1. Acero, F., Ackermann, M., Ajello, M., Albert, A., Atwood, W.B., Axelsson, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Belfiore, A., Bellazzini, R., Bissaldi, E., Blandford, R.D., Bloom, E.D., Bogart, J.R., Bonino, R., Bottacini, E., Bregeon, J., Britto, R.J., Bruel, P., Buehler, R., Burnett, T.H., Buson, S., Caliandro, G.A., Cameron, R.A., Caputo, R., Caragiulo, M., Caraveo, P.A., Casandjian, J.M., Cavazzuti, E., Charles, E., Chaves, R.C.G., Chekhtman, A., Cheung, C.C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L.R., Conrad, J., Cutini, S., D’Ammando, F., de Angelis, A., DeKlotz, M., de Palma, F., Desiante, R., Digel, S.W., Di Venere, L., Drell, P.S., Dubois, R., Dumora, D., Favuzzi, C., Fegan, S.J., Ferrara, E.C., Finke, J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giebels, B., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I.A., Grondin, M.-H., Grove, J.E., Guillemot, L., Guiriec, S., Hadasch, D., Harding, A.K., Hays, E., Hewitt, J.W., Hill, A.B., Horan, D., Iafrate, G., Jogler, T., Jóhannesson, G., Johnson, R.P., Johnson, A.S., Johnson, T.J., Johnson, W.N., Kamae, T., Kataoka, J., Katsuta, J., Kuss, M., La Mura, G., Landriu, D., Larsson, S., Latronico, L., Lemoine-Goumard, M., Li, J., Li, L., Longo, F., Loparco, F., Lott, B., Lovellette, M.N., Lubrano, P., Madejski, G.M., Massaro, F., Mayer, M., Mazziotta, M.N., McEnery, J.E., Michelson, P.F., Mirabal, N., Mizuno, T., Moiseev, A.A., Mongelli, M., Monzani, M.E., Morselli, A., Moskalenko, I.V., Murgia, S., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J.F., Paneque, D., Panetta, J.H., Perkins, J.S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T.A., Racusin, J.L., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Rochester, L.S., Romani, R.W., Salvetti, D., Sánchez-Conde, M., Saz Parkinson, P.M., Schulz, A., Siskind, E.J., Smith, D.A., Spada, F., Spandre, G., Spinelli, P., Stephens, T.E., Strong, A.W., Suson, D.J., Takahashi, H., Takahashi, T., Tanaka, Y., Thayer, J.G., Thayer, J.B., Thompson, D.J., Tibaldo, L., Tibolla, O., Torres, D.F., Torresi, E., Tosti, G., Troja, E., Van Klaveren, B., Vianello, G., Winer, B.L., Wood, K.S., Wood, M., Zimmer, S., Fermi-LAT Collaboration: Astron. Astrophys. Suppl. Ser. 218, 23 (2015). 1501.02003. ADSCrossRefGoogle Scholar
  2. Archibald, A.M., Stairs, I.H., Ransom, S.M., Kaspi, V.M., Kondratiev, V.I., Lorimer, D.R., McLaughlin, M.A., Boyles, J., Hessels, J.W.T., Lynch, R., van Leeuwen, J., Roberts, M.S.E., Jenet, F., Champion, D.J., Rosen, R., Barlow, B.N., Dunlap, B.H., Remillard, R.A.: Science 324, 1411 (2009). 0905.3397. ADSCrossRefGoogle Scholar
  3. Baldwin, J.A., Phillips, M.M., Terlevich, R.: Publ. Astron. Soc. Pac. 93, 5 (1981). ADSCrossRefGoogle Scholar
  4. Barthelmy, S.D., Barbier, L.M., Cummings, J.R., Fenimore, E.E., Gehrels, N., Hullinger, D., Krimm, H.A., Markwardt, C.B., Palmer, D.M., Parsons, A., Sato, G., Suzuki, M., Takahashi, T., Tashiro, M., Tueller, J.: Space Sci. Rev. 120, 143 (2005). astro-ph/0507410. ADSCrossRefGoogle Scholar
  5. Bassani, L., Dadina, M., Maiolino, R., Salvati, M., Risaliti, G., Della Ceca, R., Matt, G., Zamorani, G.: Astron. Astrophys. Suppl. Ser. 121, 473 (1999). astro-ph/9811074. ADSCrossRefGoogle Scholar
  6. Baumgartner, W.H., Tueller, J., Markwardt, C.B., Skinner, G.K., Barthelmy, S., Mushotzky, R.F., Evans, P.A., Gehrels, N.: Astron. Astrophys. Suppl. Ser. 207, 19 (2013). 1212.3336. ADSCrossRefGoogle Scholar
  7. Becker, R.H., White, R.L., Helfand, D.J.: Astrophys. J. 450, 559 (1995). ADSCrossRefGoogle Scholar
  8. Berney, S., Koss, M., Trakhtenbrot, B., Ricci, C., Lamperti, I., Schawinski, K., Baloković, M., Crenshaw, D.M., Fischer, T., Gehrels, N., Harrison, F., Hashimoto, Y., Ichikawa, K., Mushotzky, R., Oh, K., Stern, D., Treister, E., Ueda, Y., Veilleux, S., Winter, L.: Mon. Not. R. Astron. Soc. 454, 3622 (2015). 1509.05425. ADSCrossRefGoogle Scholar
  9. Bird, A.J., Bazzano, A., Malizia, A., Fiocchi, M., Sguera, V., Bassani, L., Hill, A.B., Ubertini, P., Winkler, C.: Astron. Astrophys. Suppl. Ser. 223, 15 (2016). 1601.06074. ADSCrossRefGoogle Scholar
  10. Bohlin, R.C., Savage, B.D., Drake, J.F.: Astrophys. J. 224, 132 (1978). ADSCrossRefGoogle Scholar
  11. Byrd, G.G., Sundelius, B., Valtonen, M.: Astron. Astrophys. 171, 16 (1987) ADSGoogle Scholar
  12. Cardelli, J.A., Clayton, G.C., Mathis, J.S.: Astrophys. J. 345, 245 (1989). ADSCrossRefGoogle Scholar
  13. Coleiro, A., Chaty, S.: Astrophys. J. 764, 185 (2013). 1212.5460. ADSCrossRefGoogle Scholar
  14. Comastri, A., Mignoli, M., Ciliegi, P., Severgnini, P., Maiolino, R., Brusa, M., Fiore, F., Baldi, A., Molendi, S., Morganti, R., Vignali, C., La Franca, F., Matt, G., Perola, G.C.: Astrophys. J. 571, 771 (2002). astro-ph/0202080. ADSCrossRefGoogle Scholar
  15. Condon, J.J., Cotton, W.D., Greisen, E.W., Yin, Q.F., Perley, R.A., Taylor, G.B., Broderick, J.J.: Astron. J. 115, 1693 (1998). ADSCrossRefGoogle Scholar
  16. Coppejans, D.L., Körding, E.G., Miller-Jones, J.C.A., Rupen, M.P., Sivakoff, G.R., Knigge, C., Groot, P.J., Woudt, P.A., Waagen, E.O., Templeton, M.: Mon. Not. R. Astron. Soc. 463, 2229 (2016). 1608.06295. ADSCrossRefGoogle Scholar
  17. Cotini, S., Ripamonti, E., Caccianiga, A., Colpi, M., Della Ceca, R., Mapelli, M., Severgnini, P., Segreto, A.: Mon. Not. R. Astron. Soc. 431, 2661 (2013). 1303.0036. ADSCrossRefGoogle Scholar
  18. Cusumano, G., La Parola, V., Segreto, A., Ferrigno, C., Maselli, A., Sbarufatti, B., Romano, P., Chincarini, G., Giommi, P., Masetti, N., Moretti, A., Parisi, P., Tagliaferri, G.: Astron. Astrophys. 524, 64 (2010). 1009.0522. CrossRefGoogle Scholar
  19. D’Abrusco, R., Massaro, F., Paggi, A., Smith, H.A., Masetti, N., Landoni, M., Tosti, G.: Astron. Astrophys. Suppl. Ser. 215, 14 (2014). 1410.0029. ADSCrossRefGoogle Scholar
  20. Dadina, M.: Astron. Astrophys. 485, 417 (2008). 0801.4338. ADSCrossRefGoogle Scholar
  21. de Martino, D., Belloni, T., Falanga, M., Papitto, A., Motta, S., Pellizzoni, A., Evangelista, Y., Piano, G., Masetti, N., Bonnet-Bidaud, J.-M., Mouchet, M., Mukai, K., Possenti, A.: Astron. Astrophys. 550, 89 (2013). 1212.1615. CrossRefGoogle Scholar
  22. De Rosa, A., Vignali, C., Husemann, B., Bianchi, S., Bogdanović, T., Guainazzi, M., Herrero-Illana, R., Komossa, S., Kun, E., Loiseau, N., Paragi, Z., Perez-Torres, M., Piconcelli, E.: Mon. Not. R. Astron. Soc. 480(2), 1639 (2018). 1807.03085. ADSCrossRefGoogle Scholar
  23. Elitzur, M., Ferland, G.J., Mathews, S.G., Shields, G.A.: Astrophys. J. Lett. 272, 55 (1983). ADSCrossRefGoogle Scholar
  24. Evans, P.A., Osborne, J.P., Beardmore, A.P., Page, K.L., Willingale, R., Mountford, C.J., Pagani, C., Burrows, D.N., Kennea, J.A., Perri, M., Tagliaferri, G., Gehrels, N.: Astron. Astrophys. Suppl. Ser. 210, 8 (2014). 1311.5368. ADSCrossRefGoogle Scholar
  25. Gehrels, N., Chincarini, G., Giommi, P., Mason, K.O., Nousek, J.A., Wells, A.A., White, N.E., Barthelmy, S.D., Burrows, D.N., Cominsky, L.R., Hurley, K.C., Marshall, F.E., Mészáros, P., Roming, P.W.A., Angelini, L., Barbier, L.M., Belloni, T., Campana, S., Caraveo, P.A., Chester, M.M., Citterio, O., Cline, T.L., Cropper, M.S., Cummings, J.R., Dean, A.J., Feigelson, E.D., Fenimore, E.E., Frail, D.A., Fruchter, A.S., Garmire, G.P., Gendreau, K., Ghisellini, G., Greiner, J., Hill, J.E., Hunsberger, S.D., Krimm, H.A., Kulkarni, S.R., Kumar, P., Lebrun, F., Lloyd-Ronning, N.M., Markwardt, C.B., Mattson, B.J., Mushotzky, R.F., Norris, J.P., Osborne, J., Paczynski, B., Palmer, D.M., Park, H.-S., Parsons, A.M., Paul, J., Rees, M.J., Reynolds, C.S., Rhoads, J.E., Sasseen, T.P., Schaefer, B.E., Short, A.T., Smale, A.P., Smith, I.A., Stella, L., Tagliaferri, G., Takahashi, T., Tashiro, M., Townsley, L.K., Tueller, J., Turner, M.J.L., Vietri, M., Voges, W., Ward, M.J., Willingale, R., Zerbi, F.M., Zhang, W.W.: Astrophys. J. 611, 1005 (2004). ADSCrossRefGoogle Scholar
  26. Gómez-Guijarro, C., González-Martín, O., Ramos Almeida, C., Rodríguez-Espinosa, J.M., Gallego, J.: Mon. Not. R. Astron. Soc. 469(3), 2720 (2017). 1705.00633. ADSCrossRefGoogle Scholar
  27. Grebenev, S.A., Lutovinov, A.A., Tsygankov, S.S., Mereminskiy, I.A.: Mon. Not. R. Astron. Soc. 428, 50 (2013). 1207.1750. ADSCrossRefGoogle Scholar
  28. Gudennavar, S.B., Bubbly, S.G., Preethi, K., Murthy, J.: Astron. Astrophys. Suppl. Ser. 199, 8 (2012). ADSCrossRefGoogle Scholar
  29. Halpern, J.P.: Astron. Telegram 5208, 1 (2013) ADSGoogle Scholar
  30. Halpern, J.P., Thorstensen, J.R.: Astron. J. 150, 170 (2015). 1510.00703. ADSCrossRefGoogle Scholar
  31. Harrison, F.A., Craig, W.W., Christensen, F.E., Hailey, C.J., Zhang, W.W., Boggs, S.E., Stern, D., Cook, W.R., Forster, K., Giommi, P., Grefenstette, B.W., Kim, Y., Kitaguchi, T., Koglin, J.E., Madsen, K.K., Mao, P.H., Miyasaka, H., Mori, K., Perri, M., Pivovaroff, M.J., Puccetti, S., Rana, V.R., Westergaard, N.J., Willis, J., Zoglauer, A., An, H., Bachetti, M., Barrière, N.M., Bellm, E.C., Bhalerao, V., Brejnholt, N.F., Fuerst, F., Liebe, C.C., Markwardt, C.B., Nynka, M., Vogel, J.K., Walton, D.J., Wik, D.R., Alexander, D.M., Cominsky, L.R., Hornschemeier, A.E., Hornstrup, A., Kaspi, V.M., Madejski, G.M., Matt, G., Molendi, S., Smith, D.M., Tomsick, J.A., Ajello, M., Ballantyne, D.R., Baloković, M., Barret, D., Bauer, F.E., Blandford, R.D., Brandt, W.N., Brenneman, L.W., Chiang, J., Chakrabarty, D., Chenevez, J., Comastri, A., Dufour, F., Elvis, M., Fabian, A.C., Farrah, D., Fryer, C.L., Gotthelf, E.V., Grindlay, J.E., Helfand, D.J., Krivonos, R., Meier, D.L., Miller, J.M., Natalucci, L., Ogle, P., Ofek, E.O., Ptak, A., Reynolds, S.P., Rigby, J.R., Tagliaferri, G., Thorsett, S.E., Treister, E., Urry, C.M.: Astrophys. J. 770, 103 (2013). 1301.7307. ADSCrossRefGoogle Scholar
  32. Heckman, T.M.: Astron. Astrophys. 87, 152 (1980) ADSGoogle Scholar
  33. Heckman, T.M., Ptak, A., Hornschemeier, A., Kauffmann, G.: Astrophys. J. 634, 161 (2005). astro-ph/0507674. ADSCrossRefGoogle Scholar
  34. Hernquist, L., Mihos, J.C.: Astrophys. J. 448, 41 (1995). astro-ph/9501090. ADSCrossRefGoogle Scholar
  35. Ho, L.C., Peng, C.Y.: Astrophys. J. 555, 650 (2001). astro-ph/0102502. ADSCrossRefGoogle Scholar
  36. Jones, D.H., Saunders, W., Read, M., Colless, M.: Publ. Astron. Soc. Aust. 22, 277 (2005). astro-ph/0505068. ADSCrossRefGoogle Scholar
  37. Jones, D.H., Read, M.A., Saunders, W., Colless, M., Jarrett, T., Parker, Q.A., Fairall, A.P., Mauch, T., Sadler, E.M., Watson, F.G., Burton, D., Campbell, L.A., Cass, P., Croom, S.M., Dawe, J., Fiegert, K., Frankcombe, L., Hartley, M., Huchra, J., James, D., Kirby, E., Lahav, O., Lucey, J., Mamon, G.A., Moore, L., Peterson, B.A., Prior, S., Proust, D., Russell, K., Safouris, V., Wakamatsu, K.-I., Westra, E., Williams, M.: Mon. Not. R. Astron. Soc. 399, 683 (2009). 0903.5451. ADSCrossRefGoogle Scholar
  38. Kaspi, S., Smith, P.S., Netzer, H., Maoz, D., Jannuzi, B.T., Giveon, U.: Astrophys. J. 533, 631 (2000). astro-ph/9911476. ADSCrossRefGoogle Scholar
  39. Kauffmann, G., Heckman, T.M., Tremonti, C., Brinchmann, J., Charlot, S., White, S.D.M., Ridgway, S.E., Brinkmann, J., Fukugita, M., Hall, P.B., Ivezić, Ž., Richards, G.T., Schneider, D.P.: Mon. Not. R. Astron. Soc. 346, 1055 (2003). astro-ph/0304239. ADSCrossRefGoogle Scholar
  40. Kewley, L.J., Heisler, C.A., Dopita, M.A., Lumsden, S.: Astron. Astrophys. Suppl. Ser. 132, 37 (2001). ADSCrossRefGoogle Scholar
  41. Koss, M.J., Assef, R., Baloković, M., Stern, D., Gandhi, P., Lamperti, I., Alexander, D.M., Ballantyne, D.R., Bauer, F.E., Berney, S., Brandt, W.N., Comastri, A., Gehrels, N., Harrison, F.A., Lansbury, G., Markwardt, C., Ricci, C., Rivers, E., Schawinski, K., Trakhtenbrot, B., Treister, E., Urry, C.M.: Astrophys. J. 825, 85 (2016a). 1604.07825. ADSCrossRefGoogle Scholar
  42. Koss, M.J., Assef, R., Baloković, M., Stern, D., Gandhi, P., Lamperti, I., Alexander, D.M., Ballantyne, D.R., Bauer, F.E., Berney, S., Brandt, W.N., Comastri, A., Gehrels, N., Harrison, F.A., Lansbury, G., Markwardt, C., Ricci, C., Rivers, E., Schawinski, K., Trakhtenbrot, B., Treister, E., Urry, C.M.: Astrophys. J. 825, 85 (2016b). 1604.07825. ADSCrossRefGoogle Scholar
  43. Koss, M., Trakhtenbrot, B., Ricci, C., Lamperti, I., Oh, K., Berney, S., Schawinski, K., Baloković, M., Baronchelli, L., Crenshaw, D.M., Fischer, T., Gehrels, N., Harrison, F., Hashimoto, Y., Hogg, D., Ichikawa, K., Masetti, N., Mushotzky, R., Sartori, L., Stern, D., Treister, E., Ueda, Y., Veilleux, S., Winter, L.: Astrophys. J. 850, 74 (2017). 1707.08123. ADSCrossRefGoogle Scholar
  44. Lamastra, A., Bianchi, S., Matt, G., Perola, G.C., Barcons, X., Carrera, F.J.: Astron. Astrophys. 504, 73 (2009). 0905.4439. ADSCrossRefGoogle Scholar
  45. Landi, R., Masetti, N., Morelli, L., Palazzi, E., Bassani, L., Malizia, A., Bazzano, A., Bird, A.J., Dean, A.J., Galaz, G., Minniti, D., Ubertini, P.: Astrophys. J. 669, 109 (2007). 0706.3460. ADSCrossRefGoogle Scholar
  46. Laurent-Muehleisen, S.A., Kollgaard, R.I., Ciardullo, R., Feigelson, E.D., Brinkmann, W., Siebert, J.: Astron. Astrophys. Suppl. Ser. 118, 127 (1998). astro-ph/9711268. ADSCrossRefGoogle Scholar
  47. Maiolino, R., Salvati, M., Bassani, L., Dadina, M., Della Ceca, R., Matt, G., Risaliti, G., Zamorani, G.: Astron. Astrophys. 338, 781 (1998). astro-ph/9806055 ADSGoogle Scholar
  48. Malizia, A., Bassani, L., Bazzano, A., Bird, A.J., Masetti, N., Panessa, F., Stephen, J.B., Ubertini, P.: Mon. Not. R. Astron. Soc. 426, 1750 (2012). 1207.4882. ADSCrossRefGoogle Scholar
  49. Manzer, L.H., De Robertis, M.M.: Astrophys. J. 788, 140 (2014). ADSCrossRefGoogle Scholar
  50. Masetti, N., Parisi, P., Palazzi, E., Jiménez-Bailón, E., Chavushyan, V., McBride, V., Rojas, A.F., Steward, L., Bassani, L., Bazzano, A., Bird, A.J., Charles, P.A., Galaz, G., Landi, R., Malizia, A., Mason, E., Minniti, D., Morelli, L., Schiavone, F., Stephen, J.B., Ubertini, P.: Astron. Astrophys. 556, 120 (2013). 1307.2898. CrossRefGoogle Scholar
  51. Mason, P.A., Gray, C.: In: Vrielmann, S., Cropper, M. (eds.) IAU Colloq. 190: Magnetic Cataclysmic Variables. Astronomical Society of the Pacific Conference Series, vol. 315, p. 237 (2004) Google Scholar
  52. Massaro, E., Maselli, A., Leto, C., Marchegiani, P., Perri, M., Giommi, P., Piranomonte, S.: Astrophys. Space Sci. 357, 75 (2015). 1502.07755. ADSCrossRefGoogle Scholar
  53. Mauch, T., Murphy, T., Buttery, H.J., Curran, J., Hunstead, R.W., Piestrzynski, B., Robertson, J.G., Sadler, E.M.: Mon. Not. R. Astron. Soc. 342, 1117 (2003). astro-ph/0303188. ADSCrossRefGoogle Scholar
  54. Monet, D.G.: In: American Astronomical Society Meeting Abstracts. Bulletin of the American Astronomical Society, vol. 30, p. 1427 (1998) Google Scholar
  55. Monet, D.G., Levine, S.E., Canzian, B., Ables, H.D., Bird, A.R., Dahn, C.C., Guetter, H.H., Harris, H.C., Henden, A.A., Leggett, S.K., Levison, H.F., Luginbuhl, C.B., Martini, J., Monet, A.K.B., Munn, J.A., Pier, J.R., Rhodes, A.R., Riepe, B., Sell, S., Stone, R.C., Vrba, F.J., Walker, R.L., Westerhout, G., Brucato, R.J., Reid, I.N., Schoening, W., Hartley, M., Read, M.A., Tritton, S.B.: Astron. J. 125, 984 (2003). astro-ph/0210694. ADSCrossRefGoogle Scholar
  56. Mulchaey, J.S., Koratkar, A., Ward, M.J., Wilson, A.S., Whittle, M., Antonucci, R.R.J., Kinney, A.L., Hurt, T.: Astrophys. J. 436, 586 (1994). ADSCrossRefGoogle Scholar
  57. Murphy, T., Mauch, T., Green, A., Hunstead, R.W., Piestrzynska, B., Kels, A.P., Sztajer, P.: Mon. Not. R. Astron. Soc. 382, 382 (2007). 0708.3092. ADSCrossRefGoogle Scholar
  58. Oh, K., Koss, M., Markwardt, C.B., Schawinski, K., Baumgartner, W.H., Barthelmy, S.D., Cenko, S.B., Gehrels, N., Mushotzky, R., Petulante, A., Ricci, C., Lien, A., Trakhtenbrot, B.: Astron. Astrophys. Suppl. Ser. 235, 4 (2018). 1801.01882. ADSCrossRefGoogle Scholar
  59. Osterbrock, D.E.: Astrophysics of Gaseous Nebulae and Active Galactic Nuclei. University Science Books (1822), Mill Valley, CA (1989) CrossRefGoogle Scholar
  60. Padovani, P., Giommi, P.: Astrophys. J. 444, 567 (1995). astro-ph/9412073. ADSCrossRefGoogle Scholar
  61. Panessa, F., Bassani, L., Cappi, M., Dadina, M., Barcons, X., Carrera, F.J., Ho, L.C., Iwasawa, K.: Astron. Astrophys. 455, 173 (2006). astro-ph/0605236. ADSCrossRefGoogle Scholar
  62. Panessa, F., Carrera, F.J., Bianchi, S., Corral, A., Gastaldello, F., Barcons, X., Bassani, L., Matt, G., Monaco, L.: Mon. Not. R. Astron. Soc. 398, 1951 (2009). 0906.1974. ADSCrossRefGoogle Scholar
  63. Parisi, P., Masetti, N., Jiménez-Bailón, E., Chavushyan, V., Malizia, A., Landi, R., Molina, M., Fiocchi, M., Palazzi, E., Bassani, L., Bazzano, A., Bird, A.J., Dean, A.J., Galaz, G., Mason, E., Minniti, D., Morelli, L., Stephen, J.B., Ubertini, P.: Astron. Astrophys. 507, 1345 (2009). 0909.5345. ADSCrossRefGoogle Scholar
  64. Parisi, P., Masetti, N., Jiménez-Bailón, E., Chavushyan, V., Palazzi, E., Landi, R., Malizia, A., Bassani, L., Bazzano, A., Bird, A.J., Charles, P.A., Galaz, G., Mason, E., McBride, V.A., Minniti, D., Morelli, L., Schiavone, F., Ubertini, P.: Astron. Astrophys. 545, 101 (2012). 1206.5091. ADSCrossRefGoogle Scholar
  65. Parisi, P., Masetti, N., Rojas, A.F., Jiménez-Bailón, E., Chavushyan, V., Palazzi, E., Bassani, L., Bazzano, A., Bird, A.J., Galaz, G., Minniti, D., Morelli, L., Ubertini, P.: Astron. Astrophys. 561, 67 (2014). 1311.1458. ADSCrossRefGoogle Scholar
  66. Piranomonte, S., Perri, M., Giommi, P., Landt, H., Padovani, P.: Astron. Astrophys. 470, 787 (2007). 0704.1729. ADSCrossRefGoogle Scholar
  67. Raiteri, C.M., Capetti, A.: Astron. Astrophys. 587, 8 (2016). 1512.05589. ADSCrossRefGoogle Scholar
  68. Ricci, C., Trakhtenbrot, B., Koss, M.J., Ueda, Y., Del Vecchio, I., Treister, E., Schawinski, K., Paltani, S., Oh, K., Lamperti, I., Berney, S., Gandhi, P., Ichikawa, K., Bauer, F.E., Ho, L.C., Asmus, D., Beckmann, V., Soldi, S., Baloković, M., Gehrels, N., Markwardt, C.B.: Astron. Astrophys. Suppl. Ser. 233, 17 (2017). 1709.03989. ADSCrossRefGoogle Scholar
  69. Rojas, A.F., Masetti, N., Minniti, D., Jiménez-Bailón, E., Chavushyan, V., Hau, G., McBride, V.A., Bassani, L., Bazzano, A., Bird, A.J., Galaz, G., Gavignaud, I., Landi, R., Malizia, A., Morelli, L., Palazzi, E., Patiño-Álvarez, V., Stephen, J.B., Ubertini, P.: Astron. Astrophys. 602, 124 (2017). 1702.01629. CrossRefGoogle Scholar
  70. Rosen, S.R., Webb, N.A., Watson, M.G., Ballet, J., Barret, D., Braito, V., Carrera, F.J., Ceballos, M.T., Coriat, M., Della Ceca, R., Denkinson, G., Esquej, P., Farrell, S.A., Freyberg, M., Grisé, F., Guillout, P., Heil, L., Koliopanos, F., Law-Green, D., Lamer, G., Lin, D., Martino, R., Michel, L., Motch, C., Nebot Gomez-Moran, A., Page, C.G., Page, K., Page, M., Pakull, M.W., Pye, J., Read, A., Rodriguez, P., Sakano, M., Saxton, R., Schwope, A., Scott, A.E., Sturm, R., Traulsen, I., Yershov, V., Zolotukhin, I.: Astron. Astrophys. 590, 1 (2016). 1504.07051. CrossRefGoogle Scholar
  71. Rush, B., Malkan, M.A., Edelson, R.A.: Astrophys. J. 473, 130 (1996). astro-ph/9606178. ADSCrossRefGoogle Scholar
  72. Sazonov, S., Revnivtsev, M., Krivonos, R., Churazov, E., Sunyaev, R.: Astron. Astrophys. 462, 57 (2007). astro-ph/0608418. ADSCrossRefGoogle Scholar
  73. Schlafly, E.F., Finkbeiner, D.P.: Astrophys. J. 737, 103 (2011). 1012.4804. ADSCrossRefGoogle Scholar
  74. Sguera, V., Bazzano, A., Bird, A.J., Dean, A.J., Ubertini, P., Barlow, E.J., Bassani, L., Clark, D.J., Hill, A.B., Malizia, A., Molina, M., Stephen, J.B.: Astrophys. J. 646, 452 (2006). astro-ph/0603756. ADSCrossRefGoogle Scholar
  75. Skrutskie, M.F., Cutri, R.M., Stiening, R., Weinberg, M.D., Schneider, S., Carpenter, J.M., Beichman, C., Capps, R., Chester, T., Elias, J., Huchra, J., Liebert, J., Lonsdale, C., Monet, D.G., Price, S., Seitzer, P., Jarrett, T., Kirkpatrick, J.D., Gizis, J.E., Howard, E., Evans, T., Fowler, J., Fullmer, L., Hurt, R., Light, R., Kopan, E.L., Marsh, K.A., McCallon, H.L., Tam, R., Van Dyk, S., Wheelock, S.: Astron. J. 131, 1163 (2006). ADSCrossRefGoogle Scholar
  76. Stephen, J.B., Bassani, L., Malizia, A., Bazzano, A., Ubertini, P., Bird, A.J., Dean, A.J., Lebrun, F., Walter, R.: Astron. Astrophys. 445, 869 (2006). astro-ph/0509620. ADSCrossRefGoogle Scholar
  77. Stickel, M., Padovani, P., Urry, C.M., Fried, J.W., Kuehr, H.: Astrophys. J. 374, 431 (1991). ADSCrossRefGoogle Scholar
  78. Stocke, J.T., Morris, S.L., Gioia, I.M., Maccacaro, T., Schild, R., Wolter, A., Fleming, T.A., Henry, J.P.: Astron. Astrophys. Suppl. Ser. 76, 813 (1991). ADSCrossRefGoogle Scholar
  79. Strader, J., Li, K.-L., Chomiuk, L., Heinke, C.O., Udalski, A., Peacock, M., Shishkovsky, L., Tremou, E.: Astrophys. J. 831, 89 (2016). 1608.02583. ADSCrossRefGoogle Scholar
  80. Tanaka, M., Morokuma, T., Itoh, R., Akitaya, H., Tominaga, N., Saito, Y., Stawarz, Ł., Tanaka, Y.T., Gandhi, P., Ali, G., Aoki, T., Contreras, C., Doi, M., Essam, A., Hamed, G., Hsiao, E.Y., Iwata, I., Kawabata, K.S., Kawai, N., Kikuchi, Y., Kobayashi, N., Kuroda, D., Maehara, H., Matsumoto, E., Mazzali, P.A., Minezaki, T., Mito, H., Miyata, T., Miyazaki, S., Mori, K., Moritani, Y., Morokuma-Matsui, K., Morrell, N., Nagao, T., Nakada, Y., Nakata, F., Noma, C., Ohsuga, K., Okada, N., Phillips, M.M., Pian, E., Richmond, M.W., Sahu, D., Sako, S., Sarugaku, Y., Shibata, T., Soyano, T., Stritzinger, M.D., Tachibana, Y., Taddia, F., Takaki, K., Takey, A., Tarusawa, K., Ui, T., Ukita, N., Urata, Y., Walker, E.S., Yoshii, T.: Astrophys. J. Lett. 793(2), 26 (2014). 1409.1309. ADSCrossRefGoogle Scholar
  81. Terlevich, R., Melnick, J.: Mon. Not. R. Astron. Soc. 213, 841 (1985). ADSCrossRefGoogle Scholar
  82. Tran, H.D., Lyke, J.E., Mader, J.A.: Astrophys. J. Lett. 726, 21 (2011). 1012.1865. ADSCrossRefGoogle Scholar
  83. Tueller, J., Baumgartner, W.H., Markwardt, C.B., Skinner, G.K., Mushotzky, R.F., Ajello, M., Barthelmy, S., Beardmore, A., Brandt, W.N., Burrows, D., Chincarini, G., Campana, S., Cummings, J., Cusumano, G., Evans, P., Fenimore, E., Gehrels, N., Godet, O., Grupe, D., Holland, S., Kennea, J., Krimm, H.A., Koss, M., Moretti, A., Mukai, K., Osborne, J.P., Okajima, T., Pagani, C., Page, K., Palmer, D., Parsons, A., Schneider, D.P., Sakamoto, T., Sambruna, R., Sato, G., Stamatikos, M., Stroh, M., Ukwata, T., Winter, L.: Astron. Astrophys. Suppl. Ser. 186, 378 (2010). 0903.3037. ADSCrossRefGoogle Scholar
  84. Turner, T.J., George, I.M., Nandra, K., Mushotzky, R.F.: Astrophys. J. 488, 164 (1997). astro-ph/9705087. ADSCrossRefGoogle Scholar
  85. Ubertini, P., Lebrun, F., Di Cocco, G., Bazzano, A., Bird, A.J., Broenstad, K., Goldwurm, A., La Rosa, G., Labanti, C., Laurent, P., Mirabel, I.F., Quadrini, E.M., Ramsey, B., Reglero, V., Sabau, L., Sacco, B., Staubert, R., Vigroux, L., Weisskopf, M.C., Zdziarski, A.A.: Astron. Astrophys. 411, 131 (2003). ADSCrossRefGoogle Scholar
  86. Veilleux, S., Osterbrock, D.E.: Astron. Astrophys. Suppl. Ser. 63, 295 (1987). ADSCrossRefGoogle Scholar
  87. Vladilo, G., Centurión, M., Levshakov, S.A., Péroux, C., Khare, P., Kulkarni, V.P., York, D.G.: Astron. Astrophys. 454, 151 (2006). astro-ph/0604296. ADSCrossRefGoogle Scholar
  88. Vojkhanskaja, N.F.: Astrophys. Bull. 72, 191 (2017). ADSCrossRefGoogle Scholar
  89. Wakely, S.P., Horan, D.: Int. Cosm. Ray Conf. 3, 1341 (2008) Google Scholar
  90. Warner, B.: In: Buckley, D.A.H., Warner, B. (eds.) Magnetic Cataclysmic Variables. Astronomical Society of the Pacific Conference Series, vol. 85, p. 3 (1995) CrossRefGoogle Scholar
  91. Wenger, M., Ochsenbein, F., Egret, D., Dubois, P., Bonnarel, F., Borde, S., Genova, F., Jasniewicz, G., Laloë, S., Lesteven, S., Monier, R.: Astron. Astrophys. Suppl. Ser. 143, 9 (2000). astro-ph/0002110. ADSCrossRefGoogle Scholar
  92. Winkler, H.: Mon. Not. R. Astron. Soc. 257, 677 (1992). ADSCrossRefGoogle Scholar
  93. Winkler, C., Courvoisier, T.J.-L., Di Cocco, G., Gehrels, N., Giménez, A., Grebenev, S., Hermsen, W., Mas-Hesse, J.M., Lebrun, F., Lund, N., Palumbo, G.G.C., Paul, J., Roques, J.-P., Schnopper, H., Schönfelder, V., Sunyaev, R., Teegarden, B., Ubertini, P., Vedrenne, G., Dean, A.J.: Astron. Astrophys. 411, 1 (2003). ADSCrossRefGoogle Scholar
  94. Wright, E.L.: Publ. Astron. Soc. Pac. 118, 1711 (2006). astro-ph/0609593. ADSCrossRefGoogle Scholar
  95. Wright, E.L., Eisenhardt, P.R.M., Mainzer, A.K., Ressler, M.E., Cutri, R.M., Jarrett, T., Kirkpatrick, J.D., Padgett, D., McMillan, R.S., Skrutskie, M., Stanford, S.A., Cohen, M., Walker, R.G., Mather, J.C., Leisawitz, D., Gautier, T.N. III, McLean, I., Benford, D., Lonsdale, C.J., Blain, A., Mendez, B., Irace, W.R., Duval, V., Liu, F., Royer, D., Heinrichsen, I., Howard, J., Shannon, M., Kendall, M., Walsh, A.L., Larsen, M., Cardon, J.G., Schick, S., Schwalm, M., Abid, M., Fabinsky, B., Naes, L., Tsai, C.-W.: Astron. J. 140, 1868 (2010). 1008.0031. ADSCrossRefGoogle Scholar
  96. Wu, X.-B., Wang, R., Kong, M.Z., Liu, F.K., Han, J.L.: Astron. Astrophys. 424, 793 (2004). astro-ph/0403243. ADSCrossRefGoogle Scholar
  97. Zhou, H., Wang, T., Yuan, W., Lu, H., Dong, X., Wang, J., Lu, Y.: Astron. Astrophys. Suppl. Ser. 166(1), 128 (2006). astro-ph/0603759. ADSCrossRefGoogle Scholar

Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  • E. J. Marchesini
    • 1
    • 2
    • 3
    • 4
    • 5
  • N. Masetti
    • 5
    • 6
  • E. Palazzi
    • 5
  • V. Chavushyan
    • 7
  • E. Jiménez-Bailón
    • 8
  • V. M. Patiño-Álvarez
    • 7
    • 9
  • V. Reynaldi
    • 1
    • 2
  • A. F. Rojas
    • 10
    • 6
  • I. Saviane
    • 10
  • I. Andruchow
    • 1
    • 2
  • L. Bassani
    • 5
  • A. Bazzano
    • 11
  • A. J. Bird
    • 12
  • A. Malizia
    • 5
  • D. Minniti
    • 13
    • 14
    • 6
  • L. Monaco
    • 6
  • J. B. Stephen
    • 5
  • P. Ubertini
    • 11
  1. 1.Facultad de Ciencias Astronómicas y GeofísicasUniversidad Nacional de La PlataLa PlataArgentina
  2. 2.Instituto de Astrofísica de La Plata, CONICET–UNLP, CCT La PlataLa PlataArgentina
  3. 3.Dipartimento di FisicaUniversità degli Studi di TorinoTurinItaly
  4. 4.INFN – Istituto Nazionale di Fisica NucleareTurinItaly
  5. 5.INAF – Osservatorio di Astrofisica e Scienza dello SpazioBolognaItaly
  6. 6.Departamento de Ciencias FisicasUniversidad Andres BelloLas Condes, SantiagoChile
  7. 7.Instituto Nacional de Astrofísica, Óptica y ElectrónicaPueblaMexico
  8. 8.Universidad Nacional Autoónoma de MéxicoMéxico D.F.Mexico
  9. 9.Max-Planck-Institut für RadioastronomieBonnGermany
  10. 10.European Southern ObservatorySantiagoChile
  11. 11.INAF–Istituto di Astrofisica e Planetologia SpazialiRomeItaly
  12. 12.University of SouthamptonPhysics & AstronomyHampshireUnited Kingdom
  13. 13.Millennium Institute of AstrophysicsMacul, SantiagoChile
  14. 14.Vatican ObservatoryVatican City StateVatican City State

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