Infrared jet in a microquasar  

<p><a href="/Images/News/2444/PastedGraphic-1.jpg" target="_blank"><img style="border: 0px solid; margin: 0 8px 5px 0;" src="/Images/News/2444/PastedGraphic-1.jpg" alt="img" width="120" align="left" /></a></p> <p>The presence of a compact jet around microquasars is usually detected through radio observations. By observing at the ESO observatory the microquasar and black hole candidate XTE J1550-564 during a burst of activity in X-rays, a french team led by Sylvain Chaty, associate professor at the University of Paris Diderot - Paris 7 and a member of the laboratory AIM (CNRS, Univ. Paris 7, Service d'Astrophysique CEA-IRFU) has unambiguously detected the signature of the jet in the infrared domain, thus independently confirming its presence. Observations performed at the ESO NTT telescope during an X-ray burst in 2003 showed a sharp break in the spectral energy distribution between visible and infrared domains, a rapid variability of infrared and optical light, atypical colors and a polarization, indices which all converge towards the detection of a jet. In addition, data obtained have enabled the researchers to measure the size of the region source of this synchrotron emission (emission resulting from charged particles moving in a magnetic field), of about 2500 km. They also allowed them to determine the value of the magnetic field, 5 Tesla at the base of the jet, which to give a ``terrestrial'' comparison to a celestial phenomenon, represents a similar value to the magnetic field created by supraconducting magnets at LHC.</p> <p>&laquo;&nbsp; Near-infrared jet emission in the microquasar XTE J1550-564 &raquo;<br /> S. Chaty, G. Dubus and A. Raichoor<br /> To appear in Astronomy and Astrophysics, <a href="/Images/News/2444/xtej1550.pdf">download the paper</a> (pdf format, 960 Kb)</p> <p>See also : <br /> -&nbsp; <a href="http://www.univ-paris-diderot.fr/sc/site.php?bc=recherche&amp;np=pageActu&amp;num=2860" target="_blank"> more informations </a> on the Paris-Diderot University website</p> <p>&nbsp;</p> <p>Contact:<br /> <a href="mailto:sylvain.chaty@cea.fr">Sylvain Chaty</a></p>

gouiffe, 2011-02-24 00:00:00