Title

Gamma-rays from the quasar PKS 1441+25: story of an escape

Authors

P. T. Reynolds, Department of Physical Sciences, Cork Institute of Technology, Bishopstown, Cork, Ireland
et al

Document Type

Article

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Disciplines

Astrophysics and Astronomy | Cosmology, Relativity, and Gravity | External Galaxies | Stars, Interstellar Medium and the Galaxy

Publication Details

Astrophysical Letters

Abstract

Outbursts from gamma-ray quasars provide insights on the relativistic jets of active galactic nuclei and constraints on the diffuse radiation fields that fill the universe. The detection of significant emission above 100 GeV from a distant quasar would show that some of the radiated gamma-rays escape pair-production interactions with low-energy photons, be it the extragalactic background light (EBL), or the radiation near the supermassive black hole lying at the jet's base. VERITAS detected gamma-ray emission up to ~200 GeV from PKS 1441+25 (z = 0.939) during 2015 April, a period of high activity across all wavelengths. This observation of PKS 1441+25 suggests that the emission region is located thousands of Schwarzschild radii away from the black hole. The gamma-ray detection also sets a stringent upper limit on the near-ultraviolet to near-infrared EBL intensity, suggesting that galaxy surveys have resolved most, if not all, of the sources of the EBL at these wavelengths.

Recommended Citation

Abeysekara, A.U., Archambault, S., Archer, A., Aune, T., Barnacka, A., Benbow, W., Bird, R., Biteau, J., Buckley, J.H., Bugaev, V., Cardenzana, J.V., Cerruti, M., Chen, X., Christiansen, J.L., Ciupik, L., Connolly, M.P., Coppi, P., Cui, W., Dickinson, H.J., Dumm, J., Eisch, J.D., Errando, M., Falcone, A., Feng, Q., Finley, J.P., Fleischhack, H., Flinders, A., Fortin, P., Fortson, L., Furniss, A., Gillanders, G.H., Griffin, S., Grube, J., Gyuk, G., Hütten, M., Håkansson, N., Hanna, D., Holder, J., Humensky, T.B., Johnson, C.A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Khassen, Y., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M.J., Maier, G., McArthur, S., McCann, A., Meagher, K., Moriarty, P., Mukherjee, R., Nieto, D., Bhróithe, A.O. de, Ong, R.A., Otte, A.N., Park, N., Perkins, J.S., Petrashyk, A., Pohl, M., Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Ratliff, G., Reynolds, P.T., Richards, G.T., Roache, E., Rousselle, J., Santander, M., Sembroski, G.H., Shahinyan, K., Smith, A.W., Staszak, D., Telezhinsky, I., Todd, N.W., Tucci, J.V., Tyler, J., Vassiliev, V.V., Vincent, S., Wakely, S.P., Weiner, O.M., Weinstein, A., Wilhelm, A., Williams, D.A., Zitzer, B., Smith, P.S., Holoien, T.W.-S., Prieto, J.L., Kochanek, C.S., Stanek, K.Z., Shappee, B., Hovatta, T., Max-Moerbeck, W., Pearson, T.J., Reeves, R.A., Richards, J.L., Readhead, A.C.S., Madejski, G.M., Djorgovski, S.G., Drake, A.J., Graham, M.J. and Mahabal, A. (2015). GAMMA-RAYS FROM THE QUASAR PKS 1441+25: STORY OF AN ESCAPE. The Astrophysical Journal, 815(2), p.L22. Available at: https://iopscience.iop.org/article/10.1088/2041-8205/815/2/L22 ‌