2026-04-17T02:36:22Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1138672025-12-05T16:48:02Zcom_2072_1057col_2072_478823col_2072_478904col_2072_478917

00925njm 22002777a 4500 dc Marcote Martin, Benito author Ribó Gomis, Marc author Paredes i Poy, Josep Maria author Ishwara-Chandra, C. H. author Swinbank, J. D. author Broderick, J. W. author Markoff, Sera author Fender, R. P. author Wijers, R. A. M. J. author Pooley, G. author Stewart, A. J. author Bell, M. E. author Breton, R. P. author Carbone, D. author Corbel, S. author Eislöffel, J. author Falcke, H. author Grießmeier, J. M. author Kuniyoshi, M. author Pietka, M. author Rowlinson, A. author Serylak, M. author van der Horst, A. J author van Leeuwen, J. author Wise, M. W. author Zarka, P. author 2017-07-17T08:17:49Z 2017-07-17T08:17:49Z 2016-02-21 2017-07-17T08:17:49Z LS I +61 303 is a gamma-ray binary that exhibits an outburst at GHz frequencies each orbital cycle of ≈26.5 d and a superorbital modulation with a period of ≈4.6 yr. We have performed a detailed study of the low-frequency radio emission of LS I +61 303 by analysing all the archival Giant Metrewave Radio Telescope data at 150, 235 and 610 MHz, and conducting regular LOw Frequency ARray observations within the Radio Sky Monitor (RSM) at 150 MHz. We have detected the source for the first time at 150 MHz, which is also the first detection of a gamma-ray binary at such a low frequency. We have obtained the light curves of the source at 150, 235 and 610 MHz, all of them showing orbital modulation. The light curves at 235 and 610 MHz also show the existence of superorbital variability. A comparison with contemporaneous 15-GHz data shows remarkable differences with these light curves. At 15 GHz we see clear outbursts, whereas at low frequencies we see variability with wide maxima. The light curve at 235 MHz seems to be anticorrelated with the one at 610 MHz, implying a shift of ∼0.5 orbital phases in the maxima. We model the shifts between the maxima at different frequencies as due to the expansion of a one-zone emitting region assuming either free-free absorption or synchrotron self-absorption with two different magnetic field dependences. We always obtain a subrelativistic expansion velocity, in some cases being close to the stellar wind one. Raigs gamma Estels binaris Astrofísica Gamma rays Double stars Astrophysics Orbital and superorbital variability of LS I +61 303 at low radio frequencies with GMRT and LOFAR