The Astrophysical Journal (Jan 2024)
A Multiwavelength Study to Decipher the 2017 Flare of the Blazar OJ 287
- A. Acharyya,
- C. B. Adams,
- A. Archer,
- P. Bangale,
- J. T. Bartkoske,
- P. Batista,
- W. Benbow,
- A. Brill,
- J. P. Caldwell,
- M. Carini,
- J. L. Christiansen,
- A. J. Chromey,
- M. Errando,
- A. Falcone,
- Q. Feng,
- J. P. Finley,
- J. Foote,
- L. Fortson,
- A. Furniss,
- G. Gallagher,
- W. Hanlon,
- D. Hanna,
- O. Hervet,
- C. E. Hinrichs,
- J. Hoang,
- J. Holder,
- T. B. Humensky,
- W. Jin,
- M. N. Johnson,
- P. Kaaret,
- M. Kertzman,
- M. Kherlakian,
- D. Kieda,
- T. K. Kleiner,
- N. Korzoun,
- F. Krennrich,
- S. Kumar,
- M. J. Lang,
- M. Lundy,
- G. Maier,
- C. E McGrath,
- M. J. Millard,
- J. Millis,
- C. L. Mooney,
- P. Moriarty,
- R. Mukherjee,
- S. O’Brien,
- R. A. Ong,
- M. Pohl,
- E. Pueschel,
- J. Quinn,
- P. L. Rabinowitz,
- K. Ragan,
- P. T. Reynolds,
- D. Ribeiro,
- E. Roache,
- J. L. Ryan,
- I. Sadeh,
- A. C. Sadun,
- L. Saha,
- M. Santander,
- G. H. Sembroski,
- K. Shahinyan,
- R. Shang,
- M. Splettstoesser,
- D. Tak,
- A. K. Talluri,
- J. V. Tucci,
- D. A. Williams,
- S. L. Wong,
- (VERITAS Collaboration),
- S. G. Jorstad,
- R. Lico,
- P. Lusen,
- A. P. Marscher
Affiliations
- A. Acharyya
- ORCiD
- Department of Physics and Astronomy, University of Alabama , Tuscaloosa, AL 35487, USA
- C. B. Adams
- ORCiD
- Physics Department, Columbia University , New York, NY 10027, USA
- A. Archer
- Department of Physics and Astronomy, DePauw University , Greencastle, IN 46135-0037, USA
- P. Bangale
- ORCiD
- Department of Physics and Astronomy and the Bartol Research Institute, University of Delaware , Newark, DE 19716, USA
- J. T. Bartkoske
- ORCiD
- Department of Physics and Astronomy, University of Utah , Salt Lake City, UT 84112, USA
- P. Batista
- DESY , Platanenallee 6, 15738 Zeuthen, Germany
- W. Benbow
- ORCiD
- Center for Astrophysics ∣ Harvard & Smithsonian , Cambridge, MA 02138, USA
- A. Brill
- ORCiD
- NASA/Goddard Space Flight Center , Code 661, Greenbelt, MD 20771, USA
- J. P. Caldwell
- Aerospace Engineering Department, California Polytechnic State University , San Luis Obispo, CA 93407, USA
- M. Carini
- Western Kentucky University , Bowling Green, KY 42101, USA
- J. L. Christiansen
- Physics Department, California Polytechnic State University , San Luis Obispo, CA 94307, USA
- A. J. Chromey
- Center for Astrophysics ∣ Harvard & Smithsonian , Cambridge, MA 02138, USA
- M. Errando
- ORCiD
- Department of Physics, Washington University , St. Louis, MO 63130, USA
- A. Falcone
- ORCiD
- Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University , University Park, PA 16802, USA
- Q. Feng
- ORCiD
- Department of Physics and Astronomy, University of Utah , Salt Lake City, UT 84112, USA
- J. P. Finley
- Department of Physics and Astronomy, Purdue University , West Lafayette, IN 47907, USA
- J. Foote
- ORCiD
- Department of Physics and Astronomy and the Bartol Research Institute, University of Delaware , Newark, DE 19716, USA
- L. Fortson
- ORCiD
- School of Physics and Astronomy, University of Minnesota , Minneapolis, MN 55455, USA
- A. Furniss
- ORCiD
- Department of Physics, California State University - East Bay , Hayward, CA 94542, USA
- G. Gallagher
- Department of Physics and Astronomy, Ball State University , Muncie, IN 47306, USA
- W. Hanlon
- ORCiD
- Center for Astrophysics ∣ Harvard & Smithsonian , Cambridge, MA 02138, USA
- D. Hanna
- ORCiD
- Physics Department, McGill University , Montreal, QC H3A 2T8, Canada ; [email protected]
- O. Hervet
- ORCiD
- Santa Cruz Institute for Particle Physics and Department of Physics, University of California , Santa Cruz, CA 95064, USA ; [email protected]
- C. E. Hinrichs
- ORCiD
- Center for Astrophysics ∣ Harvard & Smithsonian , Cambridge, MA 02138, USA; Department of Physics and Astronomy, Dartmouth College , 6127 Wilder Laboratory, Hanover, NH 03755, USA
- J. Hoang
- Santa Cruz Institute for Particle Physics and Department of Physics, University of California , Santa Cruz, CA 95064, USA ; [email protected]
- J. Holder
- ORCiD
- Department of Physics and Astronomy and the Bartol Research Institute, University of Delaware , Newark, DE 19716, USA
- T. B. Humensky
- ORCiD
- NASA/Goddard Space Flight Center , Code 661, Greenbelt, MD 20771, USA; Department of Physics, University of Maryland , College Park, MD, USA
- W. Jin
- ORCiD
- Department of Physics and Astronomy, University of California , Los Angeles, CA 90095, USA
- M. N. Johnson
- ORCiD
- Santa Cruz Institute for Particle Physics and Department of Physics, University of California , Santa Cruz, CA 95064, USA ; [email protected]
- P. Kaaret
- ORCiD
- Department of Physics and Astronomy, University of Iowa , Van Allen Hall, Iowa City, IA 52242, USA
- M. Kertzman
- Department of Physics and Astronomy, DePauw University , Greencastle, IN 46135-0037, USA
- M. Kherlakian
- DESY , Platanenallee 6, 15738 Zeuthen, Germany
- D. Kieda
- ORCiD
- Department of Physics and Astronomy, University of Utah , Salt Lake City, UT 84112, USA
- T. K. Kleiner
- ORCiD
- DESY , Platanenallee 6, 15738 Zeuthen, Germany
- N. Korzoun
- ORCiD
- Department of Physics and Astronomy and the Bartol Research Institute, University of Delaware , Newark, DE 19716, USA
- F. Krennrich
- Department of Physics and Astronomy, Iowa State University , Ames, IA 50011, USA
- S. Kumar
- ORCiD
- Department of Physics, University of Maryland , College Park, MD, USA
- M. J. Lang
- ORCiD
- School of Natural Sciences, University of Galway , University Road, Galway, H91 TK33, Ireland
- M. Lundy
- ORCiD
- Physics Department, McGill University , Montreal, QC H3A 2T8, Canada ; [email protected]
- G. Maier
- ORCiD
- DESY , Platanenallee 6, 15738 Zeuthen, Germany
- C. E McGrath
- School of Physics, University College Dublin , Belfield, Dublin 4, Ireland
- M. J. Millard
- ORCiD
- Department of Physics and Astronomy, University of Iowa , Van Allen Hall, Iowa City, IA 52242, USA
- J. Millis
- Department of Physics and Astronomy, Ball State University , Muncie, IN 47306, USA
- C. L. Mooney
- ORCiD
- Department of Physics and Astronomy and the Bartol Research Institute, University of Delaware , Newark, DE 19716, USA
- P. Moriarty
- ORCiD
- School of Natural Sciences, University of Galway , University Road, Galway, H91 TK33, Ireland
- R. Mukherjee
- ORCiD
- Department of Physics and Astronomy, Barnard College, Columbia University , NY 10027, USA
- S. O’Brien
- ORCiD
- Physics Department, McGill University , Montreal, QC H3A 2T8, Canada ; [email protected]; Trottier Space Institute, McGill University , Montreal, QC H3A 2A7, Canada; Arthur B. McDonald Canadian Astroparticle Physics Research Institute, 64 Bader Lane, Queen’s University , Kingston, ON K7L 3N6, Canada
- R. A. Ong
- ORCiD
- Department of Physics and Astronomy, University of California , Los Angeles, CA 90095, USA
- M. Pohl
- ORCiD
- DESY , Platanenallee 6, 15738 Zeuthen, Germany; Institute of Physics and Astronomy, University of Potsdam , 14476 Potsdam-Golm, Germany
- E. Pueschel
- ORCiD
- Fakultät für Physik & Astronomie, Ruhr-Universität Bochum , D-44780 Bochum, Germany
- J. Quinn
- ORCiD
- School of Physics, University College Dublin , Belfield, Dublin 4, Ireland
- P. L. Rabinowitz
- Department of Physics, Washington University , St. Louis, MO 63130, USA
- K. Ragan
- ORCiD
- Physics Department, McGill University , Montreal, QC H3A 2T8, Canada ; [email protected]
- P. T. Reynolds
- Department of Physical Sciences, Munster Technological University , Bishopstown, Cork, T12 P928, Ireland
- D. Ribeiro
- ORCiD
- School of Physics and Astronomy, University of Minnesota , Minneapolis, MN 55455, USA
- E. Roache
- Center for Astrophysics ∣ Harvard & Smithsonian , Cambridge, MA 02138, USA
- J. L. Ryan
- ORCiD
- Department of Physics and Astronomy, University of California , Los Angeles, CA 90095, USA
- I. Sadeh
- ORCiD
- DESY , Platanenallee 6, 15738 Zeuthen, Germany
- A. C. Sadun
- Department of Physics, University of Colorado Denver , Campus Box 157, P.O. Box 173364, Denver, CO 80217, USA
- L. Saha
- ORCiD
- Center for Astrophysics ∣ Harvard & Smithsonian , Cambridge, MA 02138, USA
- M. Santander
- Department of Physics and Astronomy, University of Alabama , Tuscaloosa, AL 35487, USA
- G. H. Sembroski
- Department of Physics and Astronomy, Purdue University , West Lafayette, IN 47907, USA
- K. Shahinyan
- School of Physics and Astronomy, University of Minnesota , Minneapolis, MN 55455, USA
- R. Shang
- ORCiD
- Department of Physics and Astronomy, Barnard College, Columbia University , NY 10027, USA
- M. Splettstoesser
- ORCiD
- Santa Cruz Institute for Particle Physics and Department of Physics, University of California , Santa Cruz, CA 95064, USA ; [email protected]
- D. Tak
- ORCiD
- SNU Astronomy Research Center, Seoul National University , Seoul 08826, Republic of Korea
- A. K. Talluri
- School of Physics and Astronomy, University of Minnesota , Minneapolis, MN 55455, USA
- J. V. Tucci
- Department of Physics, Indiana University–Purdue University Indianapolis , Indianapolis, IN 46202, USA
- D. A. Williams
- ORCiD
- Santa Cruz Institute for Particle Physics and Department of Physics, University of California , Santa Cruz, CA 95064, USA ; [email protected]
- S. L. Wong
- ORCiD
- Physics Department, McGill University , Montreal, QC H3A 2T8, Canada ; [email protected]
- (VERITAS Collaboration)
- S. G. Jorstad
- ORCiD
- Institute for Astrophysical Research, Boston University , 725 Commonwealth Avenue, Boston, MA 02215, USA
- R. Lico
- ORCiD
- Instituto de Astrofísica de Andalucía , IAA-CSIC, Apdo. 3004, 18080 Granada, Spain; INAF Istituto di Radioastronomia , via Gobetti 101, 40129 Bologna, Italy
- P. Lusen
- Santa Cruz Institute for Particle Physics and Department of Physics, University of California , Santa Cruz, CA 95064, USA ; [email protected]
- A. P. Marscher
- ORCiD
- Institute for Astrophysical Research, Boston University , 725 Commonwealth Avenue, Boston, MA 02215, USA
- DOI
- https://doi.org/10.3847/1538-4357/ad64d0
- Journal volume & issue
-
Vol. 973,
no. 2
p. 134
Abstract
In 2017 February, the blazar OJ 287 underwent a period of intense multiwavelength activity. It reached a new historic peak in the soft X-ray (0.3–10 keV) band, as measured by the Swift X-ray Telescope. This event coincides with a very-high-energy (VHE) γ -ray outburst that led VERITAS to detect emission above 100 GeV, with a detection significance of 10 σ (from 2016 December 9 to 2017 March 31). The time-averaged VHE γ -ray spectrum was consistent with a soft power law (Γ = −3.81 ± 0.26) and an integral flux corresponding to ∼2.4% that of the Crab Nebula above the same energy. Contemporaneous data from multiple instruments across the electromagnetic spectrum reveal a complex flaring behavior, primarily in the soft X-ray and VHE bands. To investigate the possible origin of such an event, our study focuses on three distinct activity states: before, during, and after the 2017 February peak. The spectral energy distributions during these periods suggest the presence of at least two nonthermal emission zones, with the more compact one responsible for the observed flare. Broadband modeling results and observations of a new radio knot in the jet of OJ 287 in 2017 are consistent with a flare originating from a strong recollimation shock outside the radio core.
Keywords
