A polarised infrared flare from Sagittarius A* and the signatures of orbiting plasma hotspots

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dc.creatorTrippe, S.
dc.creatorPaumard, T.
dc.creatorOtt, T.
dc.creatorGillessen, S.
dc.creatorEisenhauer, F.
dc.creatorMartins, F.
dc.creatorGenzel, R.
dc.date2006-11-23
dc.date.accessioned2026-07-07T10:20:59Z
dc.date.available2026-07-07T10:20:59Z
dc.descriptionIn this article we summarise and discuss the infrared, radio, and X-ray emission from the supermassive black hole in the Galactic Centre, SgrA*. We include new results from near-infrared polarimetric imaging observations obtained on May 31st, 2006. In that night, a strong flare in Ks band (2.08 microns) reaching top fluxes of ~16 mJy could be observed. This flare was highly polarised (up to ~40%) and showed clear sub-structure on a time scale of 15 minutes, including a swing in the polarisation angle of about 70 degrees. For the first time we were able to observe both polarised flux and short-time variability, with high significance in the same flare event. This result adds decisive information to the puzzle of the SgrA* activity. The observed polarisation angle during the flare peak is the same as observed in two events in 2004 and 2005. Our observations strongly support the dynamical emission model of a decaying plasma hotspot orbiting SgrA* on a relativistic orbit. The observed polarisation parameters and their variability with time might allow to constrain the orientation of accretion disc and spin axis with respect to the Galaxy.
dc.description9 pages, 8 figures, accepted for publication in MNRAS
dc.identifierhttps://arxiv.org/abs/astro-ph/0611737
dc.identifierhttp://arxiv.org/abs/astro-ph/0611737
dc.identifierMon.Not.Roy.Astron.Soc.375:764-772,2007
dc.identifierdoi:10.1111/j.1365-2966.2006.11338.x
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/175029
dc.subjectAstrophysics
dc.titleA polarised infrared flare from Sagittarius A* and the signatures of orbiting plasma hotspots
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