RT Journal Article T1 Multiwavelength (radio, X-ray, and gamma-ray) observations of the gamma-ray binary LS I +61 303 A1 Antoranz Canales, Pedro A1 Barrio Uña, Juan Abel A1 Contreras González, José Luis A1 Fonseca González, María Victoria A1 Miranda Pantoja, José Miguel A1 Nieto Castaño, Daniel AB We present the results of the first multiwavelength observing campaign on the high-mass X-ray binary LS I + 61 303, comprising observations at the TeV regime with the MAGIC telescope, along with X-ray observations with Chandra, and radio interferometric observations with the MERLIN, EVN, and VLBA arrays, in 2006 October and November. From our MERLIN observations, we can exclude the existence of large-scale (similar to 100 mas) persistent radio jets. Our 5.0 GHz VLBA observations display morphological similarities to previous 8.4 GHz VLBA observations carried out at the same orbital phase, suggesting a high level of periodicity and stability in the processes behind the radio emission. This makes it unlikely that variability of the radio emission is due to the interaction of an outflow with variable wind clumps. If the radio emission is produced by a milliarcsecond scale jet, it should also show a stable, periodic behavior. It is then difficult to reconcile the absence of a large-scale jet (similar to 100 mas) in our observations with the evidence of a persistent relativistic jet reported previously. We find a possible hint of temporal correlation between the X-ray and TeV emissions and evidence for radio/TeV noncorrelation, which points to the existence of one population of particles producing the radio emission and a different one producing the X-ray and TeV emissions. Finally, we present a quasi-simultaneous energy spectrum including radio, X-ray, and TeV bands. PB IOP Publishing SN 0004-637X YR 2008 FD 2008-09-10 LK https://hdl.handle.net/20.500.14352/50829 UL https://hdl.handle.net/20.500.14352/50829 LA eng NO © The American Astronomical Society. We thank the IAC for the excellent working conditions at the ORM.We also thank the support given by the Chandra telescope and the MERLIN interferometer through their Discretionary Director Time programs, as well as the observing time provided by the e-EVN, and the NRAO VLA and VLBA interferometers via Target of Opportunity proposals.We are grateful to the anonymousreferee for the useful comments and suggestions which have improved this paper greatly. The support of the German BMBF and MPG, the Italian INFN, the Spanish MEC, the ETH esearch Grant TH34/04 3 and the PolishMNiIGrant 1P03D01028 is gratefully acknowledged. This research is partially supported by the Ramón y Cajal programme of the Spanish MEC. The European VLBI Network (EVN) is a joint facility of European, Chinese, South African and other radio astronomy institutes funded by their national research councils. e-VLBI developments in Europe are supported by EC DG-INFSO funded Communication Network Development project, EXPReS, contract 02662. MERLIN is a National Facility operated by the University of Manchester at Jodrell Bank Observatory on behalf of STFC. This work has benefited from research funding from the European Community’s sixth Framework Programme under RadioNet R113CT 2003 5058187. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. NO German BMBF NO German MPG NO Italian INFN NO Spanish MEC NO ETH Research Grant NO PolishMNiIGrant DS Docta Complutense RD 6 abr 2025