Abstract
The third Fermi source catalog lists 3033 \(\gamma \)-ray sources above \(4\sigma \) significance. More than 30% are classified as either unidentified/unassociated Gamma-ray sources (UGSs), with about 20% classified as Blazar candidates of uncertain types (BCUs). To confirm the blazar-like nature of candidate counterparts of UGSs and BCUs, we started in 2012 an optical spectroscopic follow up campaign. We report here the spectra of 36 targets with observations from the Observatorio Astronómico Nacional San Pedro Mártir, the Southern Astrophysical Research Observatory, the Kitt Peak National Observatory and the Northern Optical Telescope, between 2016 and 2017. We confirm the BL Lac nature of 23 sources, and the flat spectrum radio quasar nature of other 7 ones. We also provide redshift estimates for 19 out of these 30 confirmations, with only one being a lower limit due to spectral features ascribable to intervening systems along the line of sight. As in previous analyses, the largest fraction of now-classified BCUs belong to the class of BL Lac objects, that appear to be the most elusive class of active galactic nuclei. One of the BL Lacs identified in this work, associated with 3FGL J2213.6-4755, lies at a redshift of \(z>1.529\), making it one of the few distant gamma-ray BL Lac objects.
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Abdo, A.A., Ackermann, M., Ajello, M., et al.: Astrophys. J. 715, 429 (2010a)
Abdo, A.A., Ackermann, M., Ajello, M., et al.: Astrophys. J. Suppl. Ser. 188, 405 (2010b)
Acero, F., Donato, D., Ojha, R., et al.: Astrophys. J. 779, 133 (2013)
Acero, F., Ackermann, M., Ajello, M., et al.: Astrophys. J. Suppl. Ser. 218, 23 (2015)
Ackermann, M., Ajello, M., Allafort, A., et al.: Astrophys. J. 743, 171 (2011)
Ackermann, M., Ajello, M., Atwood, W.B., et al.: Astrophys. J. 810, 14 (2015)
Ajello, M., Romani, R.W., Gasparrini, D., et al.: Astrophys. J. 780, 73 (2014)
Alvárez Crespo, N., Massaro, F., DÁbrusco, R., et al.: Astrophys. Space Sci. 361, 316 (2016a)
Alvárez Crespo, N., Masetti, N., Landoni, M., et al.: Astron. J. 151, 32 (2016b)
Alvárez Crespo, N., Massaro, F., Milisavljevic, D., et al.: Astron. J. 151, 95 (2016c)
Andruchow, I., Romero, G.E., Cellone, S.A., et al.: Astron. Astrophys. 442, 97 (2005)
Angelakis, E., Hovatta, T., Blinov, D., et al.: Mon. Not. R. Astron. Soc. 463, 3365 (2016)
Arsioli, B., Fraga, B., Giommi, P., et al.: Astron. Astrophys. 579A, 34 (2015)
Atwood, W.B., Abdo, A.A., Ackermann, M., et al.: Astrophys. J. 697, 2 (2009). 1071
Berlin, A., Hooper, D.: Phys. Rev. D 89a, 6014 (2014)
Bernieri, E., Campana, R., Massaro, E., et al.: Astron. Astrophys. 551L, 5 (2013)
Blandford, R.D., Rees, M.J.: In: Proc. Pittsburgh Conference on BL Lac Objects, p. 328 (1978)
Blinov, D., Pavlidou, V., et al.: Mon. Not. R. Astron. Soc. 474, 1296 (2018)
Campana, R., Massaro, E., Bernieri, E., et al.: Astrophys. Space Sci. 360, 65 (2015)
Campana, R., Massaro, E., Bernieri, E., et al.: Astrophys. Space Sci. 361, 185 (2016)
Campana, R., Maselli, A., Bernieri, E., et al.: Mon. Not. R. Astron. Soc. 465, 2784 (2017)
Cowperthwaite, P.S., Massaro, F., D’Abrusco, R., et al.: Astron. J. 146, 110 (2013)
D’Abrusco, R., Massaro, F., Ajello, M., et al.: Astrophys. J. 748, 68 (2012)
D’Abrusco, R., Massaro, F., Paggi, A., et al.: Astrophys. J. Suppl. Ser. 206, 12 (2013)
D’Abrusco, R., Massaro, F., Paggi, A., et al.: Astrophys. J. Suppl. Ser. 215, 14 (2014)
Doert, M., Errando, M.: Astrophys. J. 782, 41 (2014)
Ghirlanda, G., Ghisellini, G., Tavecchio, F., et al.: Mon. Not. R. Astron. Soc. 407(2), 791 (2010)
Giroletti, M., Massaro, F., D’Abrusco, R., et al.: Astron. Astrophys. 588A, 141 (2016)
Hartman, R.C., Bertsch, D.L., Bloom, S.D., et al.: Astron. Astrophys. 123, 79 (1999)
Jorstad, S.G., Marscher, A.P., Mattox, J.R., et al.: Astrophys. J. 556, 738 (2001)
Landi, R., Bassani, L., Stephen, J.B., et al.: Astron. Astrophys. 581, A57 (2015)
Landoni, M., Massaro, F., Paggi, A., et al.: Astron. J. 149, 163 (2015a)
Landoni, M., Falomo, R., Treves, A., et al.: Astrophys. J. 150(6), 181 (2015b)
Landoni, M., Paiano, S., Falomo, R., et al.: Astrophys. J. 861, 2 (2018)
Mahony, E.K., Sadler, E.M., Croom, S.M., et al.: Mon. Not. R. Astron. Soc. 417, 2651 (2011)
Marchesini, E.J., Masetti, N., Chavushyan, V., et al.: Astron. Astrophys. 596, A10 (2016)
Maselli, A., Massaro, F., D’Abrusco, R., et al.: Astrophys. Space Sci. 357, 141 (2015)
Masetti, N., Parisi, P., Palazzi, E., et al.: Astron. Astrophys. 519, A96 (2010)
Massaro, F., D’Abrusco, R.: Astrophys. J. 827, 67 (2016)
Massaro, E., Giommi, P., Leto, C., et al.: Astron. Astrophys. 495(2), 691 (2009)
Massaro, F., D’Abrusco, R., Ajello, M., et al.: Astrophys. J. 740L, 48 (2011)
Massaro, F., D’Abrusco, R., Tosti, G., et al.: Astrophys. J. 752, 61 (2012a)
Massaro, F., D’Abrusco, R., Tosti, G., et al.: Astrophys. J.. 750, 138 (2012b)
Massaro, F., D’Abrusco, R., Paggi, A., et al.: Astrophys. J. Suppl. Ser. 209, 10 (2013a)
Massaro, F., D’Abrusco, R., Paggi, A., et al.: Astrophys. J. Suppl. Ser. 206, 13 (2013b)
Massaro, F., Giroletti, M., Paggi, A., et al.: Astrophys. J. Suppl. Ser. 208, 15 (2013c)
Massaro, F., Paggi, A., Errando, M., et al.: Astrophys. J. Suppl. Ser. 207, 16 (2013d)
Massaro, F., D’Abrusco, R., Giroletti, M., et al.: Astrophys. J. Suppl. Ser. 207, 4 (2013e)
Massaro, F., Masetti, N., D’Abrusco, R., et al.: Astron. J. 148, 66 (2014)
Massaro, F., D’Abrusco, R., Landoni, M., et al.: Astrophys. J. Suppl. Ser. 217, 2 (2015a)
Massaro, F., Landoni, M., D’Abrusco, R., et al.: Astron. Astrophys. 575A, 124 (2015b)
Massaro, E., Maselli, A., Leto, C., et al.: Astrophys. Space Sci. 357, 75 (2015c)
Massaro, F., Thompson, D.J., Ferrara, E.C.: Astron. Astrophys. Rev. 24, 2 (2016a)
Massaro, F., Álvarez Crespo, N., D’Abrusco, R., et al.: Astrophys. Space Sci. 361, 337 (2016b)
Massaro, F., Marchesini, E.J., D’Abrusco, R., et al.: Astrophys. J. 834, 113 (2017)
Nori, M., Giroletti, M., Massaro, F., et al.: Astrophys. J. Suppl. Ser. 212, 3 (2014)
Paggi, A., Massaro, F., D’Abrusco, R., et al.: Astrophys. J. Suppl. Ser. 209, 9 (2013)
Paggi, A., Milisavljevic, D., Masetti, N., et al.: Astron. J. 147, 112 (2014)
Paiano, S., Landoni, M., Falomo, R., et al.: Astrophys. J. 837(2), 144 (2017a)
Paiano, S., Landoni, M., Falomo, R., et al.: Astrophys. J. 844(2), 120 (2017b)
Paiano, S., Falomo, R., Franceschini, A., et al.: Astrophys. J. 851(2), 135 (2017c)
Paiano, S., Franceschini, A., Stamerra, A.: Mon. Not. R. Astron. Soc. 468, 4902 (2017d)
Peña-Herazo, H.A., Marchesini, E.J., Álvarez Crespo, N., et al.: Astrophys. Space Sci. 362, 228 (2017)
Pittori, C., Verrecchia, F., Chen, A.W., et al.: Astron. Astrophys. 506, 3 (2009)
Ricci, F., Massaro, F., Landoni, M., et al.: Astron. J. 149, 160 (2015)
Rojas, A.F., Masetti, N., Minniti, D., et al.: Astron. Astrophys. 602, A124 (2017)
Sandrinelli, A., Treves, A., Falomo, R., et al.: Astrophys. J. 146(6), 163 (2013)
Schlafly, E.F., Finkbeiner, D.P.: Astrophys. J. 737, 103 (2011)
Stephen, J.B., Bassani, L., Landi, R., et al.: Mon. Not. R. Astron. Soc. 408(1), 422 (2010)
Stickel, M., Padovani, P., Urry, C.M., et al.: Astrophys. J. 374, 431 (1991)
Takahashi, Y., Kataoka, J., Nakamori, T., et al.: Astrophys. J. 747, 64 (2012)
Takeuchi, Y., Kataoka, J., Maeda, K., et al.: Astrophys. J. Suppl. Ser. 208, 25 (2013)
Urry, C.M., Padovani, P.: Publ. Astron. Soc. Pac. 107, 803 (1995)
van Dokkum, P.G.: Publ. Astron. Soc. Pac. 113, 1420V (2001)
White, G.L., Jauncey, D.L., Savage, A., et al.: Astrophys. J. 327, 561 (1988)
Wright, E.L., Eisenhardt, P.R.M., Mainzer, A.K., et al.: Astron. J. 140, 1868 (2010)
Zechlin, H., Horns, D.: J. Cosmol. Astropart. Phys. 11, 050 (2012)
Acknowledgements
This work is supported by the “Departments of Excellence 2018–2022” Grant awarded by the Italian Ministry of Education, University and Research (MIUR) (L. 232/2016). This research has made use of resources provided by the Compagnia di San Paolo for the grant awarded on the BLENV project (S1618_L1_MASF_01) and by the Ministry of Education, Universities and Research for the grant MASF_FFABR_17_01. E.J.M. acknowledges the financial contribution from the Universidad Nacional de La Plata-Ay. Mov. Doctorandos 2018. F.M. acknowledges financial contribution from the agreement ASI-INAF no. 2017-14-H.0. A.P. acknowledges financial support from the Consorzio Interuniversitario per la fisica Spaziale (CIFS) under the agreement related to the grant MASF_CONTR_FIN_18_02. F.R. acknowledges the support from FONDECYT Postdoctorado 3180506 and CONICYT project Basal AFB-170002. E.J.B. acknowledges support from Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica (IN109217).
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Marchesini, E.J., Peña-Herazo, H.A., Álvarez Crespo, N. et al. Optical spectroscopic observations of gamma-ray blazar candidates VIII: the 2016–2017 follow up campaign carried out at SPM, NOT, KPNO and SOAR telescopes. Astrophys Space Sci 364, 5 (2019). https://doi.org/10.1007/s10509-018-3490-z
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DOI: https://doi.org/10.1007/s10509-018-3490-z