K2 Optical Emission from OJ 287 and Other γ-Ray Blazars on Hours-to-weeks Timescales from 2014 to 2018
We present second observations by K2 of OJ 287 and seven other γ -ray active galactic nuclei (AGNs) obtained in 2017–2018, second and third observations of the lobe-dominated, steep-spectrum quasar 3C 207, and observations of nine additional blazars not previously observed with K2. The AGNs were obs...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2023-01-01
|
| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/acd055 |
| _version_ | 1797694321553571840 |
|---|---|
| author | Ann E. Wehrle Michael Carini Paul J. Wiita Joshua Pepper B. Scott Gaudi Richard W. Pogge Keivan G. Stassun Steven Villanueva Jr. |
| author_facet | Ann E. Wehrle Michael Carini Paul J. Wiita Joshua Pepper B. Scott Gaudi Richard W. Pogge Keivan G. Stassun Steven Villanueva Jr. |
| author_sort | Ann E. Wehrle |
| collection | DOAJ |
| description | We present second observations by K2 of OJ 287 and seven other γ -ray active galactic nuclei (AGNs) obtained in 2017–2018, second and third observations of the lobe-dominated, steep-spectrum quasar 3C 207, and observations of nine additional blazars not previously observed with K2. The AGNs were observed simultaneously with K2 and the Fermi Large Area Telescope for 51–81 days. Our full sample, observed in 2014–2018, contained 16 BL Lacertae objects (BL Lacs), nine flat-spectrum radio quasars (FSRQs), and four other γ -ray AGNs. Twelve BL Lacs and seven FSRQs exhibited fast, jagged light curves, while four BL Lacs and two FSRQs had slow, smooth light curves. Some objects changed their red-noise character significantly between repeated K2 observations. The optical characteristics of OJ 287 derived from the short-cadence K2 light curves changed between observations made before and after the predicted passage of the suspected secondary supermassive black hole through the accretion disk of the primary supermassive black hole. The average slopes of the periodogram power spectral densities of the BL Lacs’ and FSRQs’ light curves differed significantly, by ≈12%, with the BL Lac slopes being steeper, and a Kolmogorov–Smirnov test with a p -value of 0.039 indicates that these samples probably come from different populations; however, this result is not as strongly supported by power spectral response (PSRESP) analyses. Differences in the origin of the jets from the ergosphere or accretion disk in these two classes could produce such a disparity, as could different sizes or locations of emission regions within the jets. |
| first_indexed | 2024-03-12T02:55:17Z |
| format | Article |
| id | doaj.art-9164891835cc4f37b3cb40f4013c597d |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T02:55:17Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-9164891835cc4f37b3cb40f4013c597d2023-09-03T15:17:53ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0195115810.3847/1538-4357/acd055K2 Optical Emission from OJ 287 and Other γ-Ray Blazars on Hours-to-weeks Timescales from 2014 to 2018Ann E. Wehrle0https://orcid.org/0000-0003-4737-1477Michael Carini1https://orcid.org/0000-0001-8961-2465Paul J. Wiita2https://orcid.org/0000-0002-1029-3746Joshua Pepper3https://orcid.org/0000-0002-3827-8417B. Scott Gaudi4https://orcid.org/0000-0003-0395-9869Richard W. Pogge5https://orcid.org/0000-0003-1435-3053Keivan G. Stassun6https://orcid.org/0000-0002-3481-9052Steven Villanueva Jr.7https://orcid.org/0000-0001-6213-8804Space Science Institute , 4765 Walnut Street, Suite B, Boulder, CO 80301, USAWestern Kentucky University , Department of Physics and Astronomy, 1906 College Heights Blvd., Bowling Green, KY 42101, USAThe College of New Jersey , Department of Physics, 2000 Pennington Rd., Ewing, NJ 08628-0718, USALehigh University , Department of Physics, 413 Lewis Laboratory, 16 Memorial Drive East, Bethlehem, PA 18015, USAThe Ohio State University , Department of Astronomy, 140 W. 18th Ave., Columbus, OH 43210, USAThe Ohio State University , Department of Astronomy, 140 W. 18th Ave., Columbus, OH 43210, USA; The Ohio State University , Center for Cosmology & AstroParticle Physics, 191 West Woodruff Ave., Columbus, OH 43210, USAVanderbilt University , Department of Physics & Astronomy, 6301 Stevenson Center Ln., Nashville, TN 37235, USAThe Ohio State University , Department of Astronomy, 140 W. 18th Ave., Columbus, OH 43210, USA; NASA Goddard Space Flight Center , Exoplanets and Stellar Astrophysics Laboratory (Code 667), Greenbelt, MD 20771, USAWe present second observations by K2 of OJ 287 and seven other γ -ray active galactic nuclei (AGNs) obtained in 2017–2018, second and third observations of the lobe-dominated, steep-spectrum quasar 3C 207, and observations of nine additional blazars not previously observed with K2. The AGNs were observed simultaneously with K2 and the Fermi Large Area Telescope for 51–81 days. Our full sample, observed in 2014–2018, contained 16 BL Lacertae objects (BL Lacs), nine flat-spectrum radio quasars (FSRQs), and four other γ -ray AGNs. Twelve BL Lacs and seven FSRQs exhibited fast, jagged light curves, while four BL Lacs and two FSRQs had slow, smooth light curves. Some objects changed their red-noise character significantly between repeated K2 observations. The optical characteristics of OJ 287 derived from the short-cadence K2 light curves changed between observations made before and after the predicted passage of the suspected secondary supermassive black hole through the accretion disk of the primary supermassive black hole. The average slopes of the periodogram power spectral densities of the BL Lacs’ and FSRQs’ light curves differed significantly, by ≈12%, with the BL Lac slopes being steeper, and a Kolmogorov–Smirnov test with a p -value of 0.039 indicates that these samples probably come from different populations; however, this result is not as strongly supported by power spectral response (PSRESP) analyses. Differences in the origin of the jets from the ergosphere or accretion disk in these two classes could produce such a disparity, as could different sizes or locations of emission regions within the jets.https://doi.org/10.3847/1538-4357/acd055Active galactic nucleiBlazarsGalaxy jets |
| spellingShingle | Ann E. Wehrle Michael Carini Paul J. Wiita Joshua Pepper B. Scott Gaudi Richard W. Pogge Keivan G. Stassun Steven Villanueva Jr. K2 Optical Emission from OJ 287 and Other γ-Ray Blazars on Hours-to-weeks Timescales from 2014 to 2018 The Astrophysical Journal Active galactic nuclei Blazars Galaxy jets |
| title | K2 Optical Emission from OJ 287 and Other γ-Ray Blazars on Hours-to-weeks Timescales from 2014 to 2018 |
| title_full | K2 Optical Emission from OJ 287 and Other γ-Ray Blazars on Hours-to-weeks Timescales from 2014 to 2018 |
| title_fullStr | K2 Optical Emission from OJ 287 and Other γ-Ray Blazars on Hours-to-weeks Timescales from 2014 to 2018 |
| title_full_unstemmed | K2 Optical Emission from OJ 287 and Other γ-Ray Blazars on Hours-to-weeks Timescales from 2014 to 2018 |
| title_short | K2 Optical Emission from OJ 287 and Other γ-Ray Blazars on Hours-to-weeks Timescales from 2014 to 2018 |
| title_sort | k2 optical emission from oj 287 and other γ ray blazars on hours to weeks timescales from 2014 to 2018 |
| topic | Active galactic nuclei Blazars Galaxy jets |
| url | https://doi.org/10.3847/1538-4357/acd055 |
| work_keys_str_mv | AT annewehrle k2opticalemissionfromoj287andothergrayblazarsonhourstoweekstimescalesfrom2014to2018 AT michaelcarini k2opticalemissionfromoj287andothergrayblazarsonhourstoweekstimescalesfrom2014to2018 AT pauljwiita k2opticalemissionfromoj287andothergrayblazarsonhourstoweekstimescalesfrom2014to2018 AT joshuapepper k2opticalemissionfromoj287andothergrayblazarsonhourstoweekstimescalesfrom2014to2018 AT bscottgaudi k2opticalemissionfromoj287andothergrayblazarsonhourstoweekstimescalesfrom2014to2018 AT richardwpogge k2opticalemissionfromoj287andothergrayblazarsonhourstoweekstimescalesfrom2014to2018 AT keivangstassun k2opticalemissionfromoj287andothergrayblazarsonhourstoweekstimescalesfrom2014to2018 AT stevenvillanuevajr k2opticalemissionfromoj287andothergrayblazarsonhourstoweekstimescalesfrom2014to2018 |