Skip to main content
SpringerLink
Log in

Optical spectroscopic observations of gamma-ray blazar candidates. IX. Optical archival spectra and further observations from SOAR and OAGH

  • Original Article
  • Published:
Astrophysics and Space Science Aims and scope Submit manuscript

Abstract

Nearly one third of the sources in the Fermi-LAT catalogs lacks a lower energy counterpart, hence being referred as unidentified/unassociated gamma-ray sources (UGSs). In order to firmly classify them, dedicated multifrequency follow-up campaigns are necessary. These will permit to unveil their nature and identify the fraction that could belong to the class of active galaxies known as blazars that is the largest population of extragalactic \(\gamma \)-ray sources. In Fermi-LAT catalogs there are also gamma-ray sources associated with multifrequency blazar-like objects known as Blazars Candidates of Uncertain type (i.e., BCUs) for which follow up spectroscopic campaigns are mandatory to confirm their blazar nature. Thus, in 2013 we started an optical spectroscopic campaign to identify blazar-like objects potential counterparts of UGSs and BCUs. Here we report the spectra of 31 additional targets observed as part of our follow up campaign. Thirteen of them are BCUs for which we acquired spectroscopic observations at Observatorio Astrofísico Guillermo Haro (OAGH) and at Southern Astrophysical Research Observatory (SOAR) telescopes, while the rest has been identified thanks to the archival observations available from the Sloan Digital Sky Survey (SDSS). We confirm the blazar nature of all BCUs: three of them are in blazar of quasar type (BZQs) while the remaining ones can be spectroscopically classified as BL Lac objects (BZBs). Then we also discovered 18 BL Lac objects lying within the positional uncertainty regions of UGSs that could be their potential counterparts.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

Notes

  1. https://fermi.gsfc.nasa.gov/ssc/data/access/lat/fl8y/.

References

  • Abdo, A.A., Ackermann, M., Ajello, M., et al.: Astrophys. J. Suppl. Ser. 188, 405 (2010a)

    ADS  Google Scholar 

  • Abdo, A.A., Ackermann, M., Ajello, M., et al.: Astrophys. J. 715, 429 (2010b)

    ADS  Google Scholar 

  • Abdo, A.A., Ackermann, M., Agudo, I., et al.: Astrophys. J. 716, 30 (2010c)

    ADS  Google Scholar 

  • Abolfathi, B., Aguado, D.S., Aguilar, G., et al.: Astrophys. J. Suppl. Ser. 235, 42 (2018)

    ADS  Google Scholar 

  • Acero, F., Donato, D., Ojha, R., et al.: Astrophys. J. 779, 133 (2013)

    ADS  Google Scholar 

  • Acero, F., Ackermann, M., Ajello, M., et al.: Astrophys. J. Suppl. Ser. 218, 23 (2015)

    ADS  Google Scholar 

  • Ackermann, M., Ajello, M., Allafort, A., et al.: Astrophys. J. 753, 83 (2012)

    ADS  Google Scholar 

  • Ackermann, M., Ajello, M., Atwood, W.B., et al.: Astrophys. J. 810, 14 (2015)

    ADS  Google Scholar 

  • Alam, S., Albareti, F.D., Allende Prieto, C., et al.: Astrophys. J. Suppl. Ser. 219, 12 (2015)

    ADS  Google Scholar 

  • Álvárez Crespo, N., Masetti, N., Landoni, M., et al.: Astron. J. 151, 32 (2016a)

    ADS  Google Scholar 

  • Álvárez Crespo, N., Massaro, F., Milisavljevic, D., et al.: Astron. J. 151, 95 (2016b)

    ADS  Google Scholar 

  • Álvarez-Crespo, N., Massaro, F., D’Abrusco, R., et al.: Astrophys. Space Sci. 361, 316 (2016c)

    ADS  Google Scholar 

  • Atwood, W.B., Abdo, A.A., Ackermann, M., et al.: Astrophys. J. 697, 1071 (2009)

    ADS  Google Scholar 

  • Blandford, Rees: In: Proc. Pittsburgh Conference on BL Lac Objects, p. 328 (1978)

    Google Scholar 

  • Cardelli, J.A., Clayton, G.C., Mathis, J.S.: Astrophys. J. 345, 245 (1989)

    ADS  Google Scholar 

  • Cheung, C.C., Donato, D., Gehrels, N., et al.: Astrophys. J. 756, 33 (2012)

    ADS  Google Scholar 

  • Clemens, J.C., Crain, J.A., Anderson, R.: Proc. SPIE 5492, 331 (2004)

    ADS  Google Scholar 

  • Condon, J.J., Cotton, W.D., Greisen, E.W., et al.: Astron. J. 115, 1693 (1998)

    ADS  Google Scholar 

  • D’Abrusco, R., Massaro, F., Ajello, M., et al.: Astrophys. J. 748, 68 (2012)

    ADS  Google Scholar 

  • D’Abrusco, R., Massaro, F., Paggi, A., et al.: Astrophys. J. Suppl. Ser. 206, 12 (2013)

    ADS  Google Scholar 

  • D’Abrusco, R., Massaro, F., Paggi, A., et al.: Astrophys. J. Suppl. Ser. 215, 14 (2014)

    ADS  Google Scholar 

  • Doert, M., Errando, M.: Astrophys. J. 782, 41 (2014)

    ADS  Google Scholar 

  • Fossati, G., Maraschi, L., et al.: Mon. Not. R. Astron. Soc. 299, 433 (1998)

    ADS  Google Scholar 

  • Giommi, P., Ansari, S.G., et al.: Astron. Astrophys. Suppl. Ser. 109, 267G (1995)

    ADS  Google Scholar 

  • Giroletti, M., Massaro, F., D’Abrusco, R., et al.: Astron. Astrophys. 588A, 141 (2016)

    Google Scholar 

  • Hartman, R.C., Bertsch, D.L., Bloom, S.D., et al.: Astrophys. J. Suppl. Ser. 123, 79 (1999)

    ADS  Google Scholar 

  • Hassan, T., Mirabal, N., Contreras, J.L., Oya, I.: Mon. Not. R. Astron. Soc. 428, 220 (2013)

    ADS  Google Scholar 

  • Healey, S.E., Romani, R.W., Taylor, G.B., et al.: Astrophys. J. Suppl. Ser. 171, 61 (2007)

    ADS  Google Scholar 

  • Hovatta, T., Lister, M.L., Aller, M.F., et al.: Astron. J. 144, 105 (2012)

    ADS  Google Scholar 

  • Hovatta, T., Aller, M.F., Aller, H.D., et al.: Astron. J. 147, 143 (2014)

    ADS  Google Scholar 

  • Jones, D.H., Read, M.A., Saunders, W., et al.: Mon. Not. R. Astron. Soc. 399, 683 (2009)

    ADS  Google Scholar 

  • Kataoka, J., Yatsu, Y., Kawai, N.: Astrophys. J. 757, 176 (2012)

    ADS  Google Scholar 

  • Kovalev, Y.Y.: Astrophys. J. 707L, 56 (2009)

    ADS  Google Scholar 

  • Landi, R., Bassani, L., Stephen, J.B., et al.: Astron. Astrophys. 581, 57 (2015)

    Google Scholar 

  • Landoni, M., Massaro, F., Paggi, A., et al.: Astron. J. 149, 163 (2015a)

    ADS  Google Scholar 

  • Landoni, M., Falomo, R., Treves, A., Scarpa, R., Reverte Payá, D.: Astron. J. 150, 181 (2015b)

    ADS  Google Scholar 

  • Landoni, M., Paiano, S., Falomo, R., et al.: Astrophys. J. 861, 130 (2018)

    ADS  Google Scholar 

  • Maeda, K., Kataoka, J., Nakamori, T., et al.: Astrophys. J. 729, 103 (2011)

    ADS  Google Scholar 

  • Marchesi, S., Kaur, A., Ajello, M.: Astron. J. 156, 212 (2018)

    ADS  Google Scholar 

  • Marchesini, E.J., Peña-Herazo, H.A., Álvarez Crespo, N., et al.: Astrophys. Space Sci. 364, 5 (2019)

    ADS  Google Scholar 

  • Massaro, F., D’Abrusco, R.: Astrophys. J. 827, 67 (2016)

    ADS  Google Scholar 

  • Massaro, E., Giommi, P., Leto, C., et al.: Astron. Astrophys. 495, 691 (2009)

    ADS  Google Scholar 

  • Massaro, F., D’Abrusco, R., Ajello, M., et al.: Astrophys. J. 740L, 48 (2011)

    ADS  Google Scholar 

  • Massaro, F., D’Abrusco, R., Tosti, G., et al.: Astrophys. J. 752, 61 (2012a)

    ADS  Google Scholar 

  • Massaro, E., Nesci, R., Piranomonte, S.: Mon. Not. R. Astron. Soc. 422, 2322 (2012b)

    ADS  Google Scholar 

  • Massaro, F., D’Abrusco, R., Tosti, G., et al.: Astrophys. J. 750, 138 (2012c)

    ADS  Google Scholar 

  • Massaro, F., D’Abrusco, R., Giroletti, M., et al.: Astrophys. J. Suppl. Ser. 207, 4 (2013a)

    ADS  Google Scholar 

  • Massaro, F., D’Abrusco, R., Paggi, A., et al.: Astrophys. J. Suppl. Ser. 206, 13 (2013b)

    ADS  Google Scholar 

  • Massaro, F., D’Abrusco, R., Paggi, A., et al.: Astrophys. J. Suppl. Ser. 209, 10 (2013c)

    ADS  Google Scholar 

  • Massaro, F., Masetti, N., D’Abrusco, R., et al.: Astron. J. 148, 66 (2014)

    ADS  Google Scholar 

  • Massaro, F., D’Abrusco, R., Landoni, M., et al.: Astrophys. J. Suppl. Ser. 217, 2 (2015a)

    ADS  Google Scholar 

  • Massaro, E., Maselli, A., Leto, C., et al.: Astrophys. Space Sci. 357, 75 (2015b)

    ADS  Google Scholar 

  • Massaro, F., Landoni, M., D’Abrusco, R., et al.: Astron. Astrophys. 575, 124 (2015c)

    Google Scholar 

  • Massaro, F., Thompson, D.J., Ferrara, E.C.: Astron. Astrophys. Rev. 24, 2 (2016a)

    ADS  Google Scholar 

  • Massaro, F., Álvarez Crespo, N., D’Abrusco, R., et al.: Astrophys. Space Sci. 361, 337 (2016b)

    ADS  Google Scholar 

  • Massaro, F., Marchesini, E.J., D’Abrusco, R., et al.: Astrophys. J. 834, 113 (2017)

    ADS  Google Scholar 

  • Mirabal, N., Halpern, J.P.: Astrophys. J. 701, 129 (2009)

    ADS  Google Scholar 

  • Nolan, P.L., Abdo, A.A., Ackermann, M., et al.: Astrophys. J. Suppl. Ser. 199, 31 (2012)

    ADS  Google Scholar 

  • Nori, M., Giroletti, M., Massaro, F., et al.: Astrophys. J. Suppl. Ser. 212, 3 (2014)

    ADS  Google Scholar 

  • Paggi, A., Massaro, F., D’Abrusco, R., et al.: Astrophys. J. Suppl. Ser. 209, 9 (2013)

    ADS  Google Scholar 

  • Paggi, A., Milisavljevic, D., Masetti, N., et al.: Astron. J. 147, 112 (2014)

    ADS  Google Scholar 

  • Paiano, S., Falomo, R., Franceschini, A., et al.: Astrophys. J. 851, 135 (2017a)

    ADS  Google Scholar 

  • Paiano, S., Landoni, M., Falomo, R., et al.: Astrophys. J. 844, 120 (2017b)

    ADS  Google Scholar 

  • Paiano, S., Landoni, M., Falomo, R., et al.: Astrophys. J. 837, 144 (2017c)

    ADS  Google Scholar 

  • Paiano, S., Falomo, R., Treves, A., Franceschini, A., Scarpa, R.: (2018). arXiv:1811.09125

  • Peña-Herazo, H.A., Marchesini, E.J., Álvarez Crespo, N., et al.: Astrophys. Space Sci. 362, 228 (2017)

    ADS  Google Scholar 

  • Petrov, L., Phillips, C., Bertarini, A., Murphy, T., Sadler, E.M.: Mon. Not. R. Astron. Soc. 414, 2528 (2011)

    ADS  Google Scholar 

  • Petrov, L., Mahony, E.K., Edwards, P.G., et al.: Mon. Not. R. Astron. Soc. 432, 1294 (2013)

    ADS  Google Scholar 

  • Ricci, F., Massaro, F., Landoni, M., et al.: Astron. J. 149, 160 (2015)

    ADS  Google Scholar 

  • Sandrinelli, A., Treves, A., Falomo, R., et al.: Astron. J. 146, 163 (2013)

    ADS  Google Scholar 

  • Schinzel, F.K., Petrov, L., Taylor, G.B.: Astrophys. J. Suppl. Ser. 217, 4 (2015)

    ADS  Google Scholar 

  • Schinzel, F.K., Petrov, L., Taylor, G.B., et al.: Astrophys. J. 838, 139 (2017)

    ADS  Google Scholar 

  • Schlafly, E.F., Finkbeiner, D.P.: Astrophys. J. 737, 103 (2011)

    ADS  Google Scholar 

  • Schlegel, D.J.: Astrophys. J. 500, 525S (1998)

    ADS  Google Scholar 

  • Shaw, M.S., Romani, R.W., Cotter, G., et al.: Astrophys. J. 764, 135 (2013a)

    ADS  Google Scholar 

  • Shaw, M.S., Filippenko, A.V., Romani, R.W., et al.: Astron. J. 146, 127 (2013b)

    ADS  Google Scholar 

  • Stickel, M., Padovani, P., Urry, C.M., et al.: Astrophys. J. 374, 431 (1991)

    ADS  Google Scholar 

  • Stroh, M.C., Falcone, A.D.: Astrophys. J. Suppl. Ser. 207, 28 (2013)

    ADS  Google Scholar 

  • Takahashi, Y., Kataoka, J., Nakamori, T., et al.: Astrophys. J. 747, 64 (2012)

    ADS  Google Scholar 

  • Takeuchi, Y., Kataoka, J., Maeda, K., et al.: Astrophys. J. Suppl. Ser. 208, 25 (2013)

    ADS  Google Scholar 

  • Taylor, M.B.: ASP Conf. Ser. 347, 29 (2005)

    ADS  Google Scholar 

  • Thompson, D.J., Bertsch, D.L., Fichtel, C.E., et al.: Astrophys. J. Suppl. Ser. 86, 629 (1993)

    ADS  Google Scholar 

  • Tody, D.: SPIE J. 627, 733 (1986)

    ADS  Google Scholar 

  • Urry, C.M., Padovani, P.: Publ. Astron. Soc. Pac. 107, 803 (1995)

    ADS  Google Scholar 

  • van Dokkum, P.G.: Publ. Astron. Soc. Pac. 113, 1420V (2001)

    ADS  Google Scholar 

Download references

Acknowledgements

PH acknowledges support from the CONACyT program for Ph.D. studies. The work of F.M. and A.P. is partially supported by the “Departments of Excellence 2018–2022” Grant awarded by the Italian Ministry of Education, University and Research (MIUR) (L. 232/2016) and 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. F.M. also acknowledges financial contribution from the agreement ASI-INAF n. 2017-14-H.0 while A.P. the financial support from the Consorzio Interuniversitario per la fisica Spaziale (CFIS) under the agreement related to the grant MASF_CONTR_FIN_18_02. F.R. acknowledges support from FONDECYT Postdoctorado 3180506 and CONICYT project Basal AFB-170002. This work was partially supported from CONACyT research grant No. 280789. We thank the staff at the Observatorio Astrofísico Guillermo Haro (OAGH) for all their help during the observation runs. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). Part of this work is based on archival data, software or on-line services provided by the ASI Science Data Center. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This research makes use of SDSS DR14 archival data. Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy Office of Science. The SDSS-III web site is http://www.sdss3.org/. SDSS-III is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS-III Collaboration including the University of Arizona, the Brazilian Participation Group, Brookhaven National Laboratory, Carnegie Mellon University, University of Florida, the French Participation Group, the German Participation Group, Harvard University, the Instituto de Astrofisica de Canarias, the Michigan State/Notre Dame/JINA Participation Group, Johns Hopkins University, Lawrence Berkeley National Laboratory, Max Planck Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, New Mexico State University, New York University, Ohio State University, Pennsylvania State University, University of Portsmouth, Princeton University, the Spanish Participation Group, University of Tokyo, University of Utah, Vanderbilt University, University of Virginia, University of Washington, and Yale University. This research has made use of the USNOFS Image and Catalogue Archive operated by the United States Naval Observatory, Flagstaff Station (http://www.nofs.navy.mil/data/fchpix/). TOPCAT (http://www.star.bris.ac.uk/~mbt/topcat/) (Taylor 2005) for the preparation and manipulation of the tabular data and the images.

Author information

Authors and Affiliations

  1. Instituto Nacional de Astrofísica, Óptica y Electrónica, Apartado Postal 51-216, 72000, Puebla, Mexico

    H. A. Peña-Herazo & V. Chavushyan

  2. Dipartimento di Fisica, Università degli Studi di Torino, via Pietro Giuria 1, 10125, Torino, Italy

    H. A. Peña-Herazo, F. Massaro, E. J. Marchesini & A. Paggi

  3. Istituto Nazionale di Fisica Nucleare, Sezione di Torino, 10125, Torino, Italy

    H. A. Peña-Herazo, F. Massaro, E. J. Marchesini & A. Paggi

  4. INAF-Osservatorio Astrofisico di Torino, via Osservatorio 20, 10025, Pino Torinese, Italy

    F. Massaro & A. Paggi

  5. Consorzio Interuniversitario per la Fisica Spaziale (CIFS), via Pietro Giuria 1, 10125, Torino, Italy

    F. Massaro & A. Paggi

  6. Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, La Plata, Argentina

    E. J. Marchesini

  7. Instituto de Astrofísica de La Plata, CONICET-UNLP, CCT La Plata, La Plata, Argentina

    E. J. Marchesini

  8. INAF – Osservatorio di Astrofisica e Scienza dello Spazio, via Gobetti 93/3, 40129, Bologna, Italy

    E. J. Marchesini & N. Masetti

  9. INAF – Osservatorio Astronomico di Brera, Via Emilio Bianchi 46, 23807, Merate, Italy

    M. Landoni

  10. Departamento de Ciencias Físicas, Universidad Andrés Bello, Fernández Concha 700, Las Condes, Santiago, Chile

    N. Masetti

  11. Instituto de Astrofísica and Centro de Astroingeniería, Facultad de Física, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22, Chile

    F. Ricci

  12. Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA, 02138, USA

    R. D’Abrusco, D. Milisavljevic & Howard A. Smith

  13. Department of Physics and Astronomy, Purdue University, 525 Northwestern Avenue, West Lafayette, IN, 47907, USA

    D. Milisavljevic

  14. Instituto de Astronomía, Universidad Nacional Autónoma de México, Apdo. Postal 877, Ensenada, 22800, Baja California, Mexico

    E. Jiménez-Bailón

  15. Dipartimento di Matematica e Fisica, Università Roma Tre, via della Vasca Navale 84, 00146, Roma, Italy

    F. La Franca

  16. Dipartimento di Fisica, Università degli Studi di Perugia, 06123, Perugia, Italy

    G. Tosti

Authors
  1. H. A. Peña-Herazo
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. F. Massaro
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. V. Chavushyan
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. E. J. Marchesini
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. A. Paggi
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. M. Landoni
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. N. Masetti
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. F. Ricci
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. R. D’Abrusco
    View author publications

    You can also search for this author in PubMed Google Scholar

  10. D. Milisavljevic
    View author publications

    You can also search for this author in PubMed Google Scholar

  11. E. Jiménez-Bailón
    View author publications

    You can also search for this author in PubMed Google Scholar

  12. F. La Franca
    View author publications

    You can also search for this author in PubMed Google Scholar

  13. Howard A. Smith
    View author publications

    You can also search for this author in PubMed Google Scholar

  14. G. Tosti
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to H. A. Peña-Herazo.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Appendices

Appendix A: Unidentified gamma ray sources

Fig. 5
figure 5

(Left panel) Optical spectrum of SDSS J002406.1+240438.3 potential candidate of the UGS with FL8Y J0024.1+2401, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J002406.1+240438.3 (red circle)

Full size image
Fig. 6
figure 6

(Left panel) Optical spectrum of SDSS J011205.78-031753.6 potential candidate of the UGS with FL8Y J0112.1-0320, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J011205.78-031753.6 (red circle)

Full size image
Fig. 7
figure 7

(Left panel) Optical spectrum of SDSS J082948.08+510827.9 potential candidate of the UGS with FL8Y J0829.7+5106, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J082948.08+510827.9 (red circle)

Full size image
Fig. 8
figure 8

(Left panel) Optical spectrum of SDSS J111346.03+152842.9 potential candidate of the UGS with FL8Y J1113.9+1527, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J111346.03+152842.9 (red circle)

Full size image
Fig. 9
figure 9

(Left panel) Optical spectrum of SDSS J113737.76+053016.5 potential candidate of the UGS with FL8Y J1137.2+0534, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J113737.76+053016.5 (red circle)

Full size image
Fig. 10
figure 10

(Left panel) Optical spectrum of SDSS J124351.76+172644.3 potential candidate of the UGS with FL8Y J1243.6+1727, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J124351.76+172644.3 (red circle)

Full size image
Fig. 11
figure 11

(Left panel) Optical spectrum of SDSS J125733.06+655100.2 potential candidate of the UGS with FL8Y J1258.4+6552, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J125733.06+655100.2 (red circle)

Full size image
Fig. 12
figure 12

(Left panel) Optical spectrum of SDSS J150316.57+165117.7 potential candidate of the UGS with FL8Y J1503.3+1651, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J150316.57+165117.7 (red circle)

Full size image
Fig. 13
figure 13

(Left panel) Optical spectrum of SDSS J151100.45+054920.8 potential candidate of the UGS with FL8Y J1511.4+0549, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J151100.45+054920.8 (red circle)

Full size image
Fig. 14
figure 14

(Left panel) Optical spectrum of SDSS J151631.37+434949.5 potential candidate of the UGS with FL8Y J1516.3+4353, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J151631.37+434949.5 (red circle)

Full size image
Fig. 15
figure 15

(Left panel) Optical spectrum of SDSS J154433.19+322149.1 potential candidate of the UGS with FL8Y J1544.9+3218, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J154433.19+322149.1 (red circle)

Full size image
Fig. 16
figure 16

(Left panel) Optical spectrum of SDSS J172100.07+251249.7 potential candidate of the UGS with FL8Y J1721.3+2529, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J172100.07+251249.7 (red circle)

Full size image
Fig. 17
figure 17

(Left panel) Optical spectrum of SDSS J220652.9+221722.2 potential candidate of the UGS with FL8Y J2207.1+2222, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J220652.9+221722.2 (red circle)

Full size image
Fig. 18
figure 18

(Left panel) Optical spectrum of SDSS J220704.1+222231.4 potential candidate of the UGS with FL8Y J2207.1+2222, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J220704.1+222231.4 (red circle)

Full size image
Fig. 19
figure 19

(Left panel) Optical spectrum of SDSS J222839.49+221125 potential candidate of the UGS with FL8Y J2228.5+2211, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J222839.49+221125 (red circle)

Full size image
Fig. 20
figure 20

(Left panel) Optical spectrum of SDSS J223704.78+184055.9 potential candidate of the UGS with FL8Y 2236.9+1840, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J223704.78+184055.9 (red circle)

Full size image
Fig. 21
figure 21

(Left panel) Optical spectrum of SDSS J224436.7+250342.6 potential candidate of the UGS with FL8Y J2244.6+2502, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: SDSS J224436.7+250342.6 (red circle)

Full size image

Appendix B: Blazar candidates of uncertain type

Fig. 22
figure 22

(Left panel) Optical spectrum of CRATES J104630+544953 associated with FL8Y J1046.1+5449, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the counterpart: CRATES J104630+544953 (red circle)

Full size image
Fig. 23
figure 23

(Left panel) Optical spectrum of WISE J112937.30+303634.4 associated with FL8Y J1129.4+3033, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the counterpart: WISE J112937.30+303634.4 (red circle)

Full size image
Fig. 24
figure 24

(Left panel) Optical spectrum of VCS J1157+1638 associated with FL8Y J1157.5+1639, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the counterpart: VCS J1157+1638 (red circle)

Full size image
Fig. 25
figure 25

(Left panel) Optical spectrum of RFC J1231+3711 associated with FL8Y J1231.1+3711, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the counterpart: RFC J1231+3711 (red circle)

Full size image
Fig. 26
figure 26

(Left panel) Optical spectrum of AT20G J131938-004939 potential candidate of the UGS with FL8Y J1319.5-0046, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the potential counterpart: AT20G J131938-004939 (red circle)

Full size image
Fig. 27
figure 27

(Left panel) Optical spectrum of Q 1326-0516 associated with FL8Y J1329.4-0530, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\) ) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the counterpart: Q 1326-0516 (red circle)

Full size image
Fig. 28
figure 28

(Left panel) Optical spectrum of WISE J133146.84-064633.1 associated with FL8Y J1331.7-0647, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the counterpart: WISE J133146.84-064633.1 (red circle)

Full size image
Fig. 29
figure 29

(Left panel) Optical spectrum of RFC J1541+1414 associated with FL8Y J1541.7+1413, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the counterpart: RFC J1541+1414 (red circle)

Full size image
Fig. 30
figure 30

(Left panel) Optical spectrum of NVSS J160005-252439 associated with FL8Y J1559.8-2525, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the counterpart: NVSS J160005-252439 (red circle)

Full size image
Fig. 31
figure 31

(Left panel) Optical spectrum of RFC J1808+3520 associated with FL8Y J1808.9+3522, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the counterpart: RFC J1808+3520 (red circle)

Full size image
Fig. 32
figure 32

(Left panel) Optical spectrum of PKS 2043-682 associated with FL8Y J2048.6-6804, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\) ) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the counterpart: PKS 2043-682 (red circle)

Full size image
Fig. 33
figure 33

(Left panel) Optical spectrum of PMN J2103-6232 associated with FL8Y J2103.8-6233, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the counterpart: PMN J2103-6232 (red circle)

Full size image
Fig. 34
figure 34

(Left panel) Optical spectrum of PMN J2211-7039 associated with 3FGL J2212.3-7039, in the upper part it is shown the Signal-to-Noise Ratio of the spectrum. (Right panel) The finding chart (\(5'\times 5'\)) retrieved from the Digitized Sky Survey (DSS) highlighting the location of the counterpart: PMN J2211-7039 (red circle)

Full size image

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Peña-Herazo, H.A., Massaro, F., Chavushyan, V. et al. Optical spectroscopic observations of gamma-ray blazar candidates. IX. Optical archival spectra and further observations from SOAR and OAGH. Astrophys Space Sci 364, 85 (2019). https://doi.org/10.1007/s10509-019-3574-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s10509-019-3574-4

Keywords

Search

Navigation