Volume 425, Number 1, October I 2004
|Page(s)||L5 - L8|
|Published online||10 September 2004|
Letter to the Editor
Correlated Infrared and X-ray variability of the transient Anomalous X-ray Pulsar XTE J1810-197*
Universitá di Roma 2, via della Ricerca Scientifica 1, 00133 Roma, Italy e-mail: email@example.com
2 INAF - Osservatorio Astronomico di Roma, via Frascati 33, 00040 Monteporzio Catone, Italy
3 Affiliated with International Center for Relativistic Astrophysics
4 CNR - IASF, Sezione di Milano “G. Occhialini”, via Bassini 15, 20133 Milano, Italy
5 Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
6 Università degli Studi di Milano, Dipartimento di Fisica, v. Celoria 16, 20133 Milano, Italy
7 CNR - IASF, Sezione di Palermo, via Ugo La Malfa 153, 90146 Palermo, Italy
8 Astrophysics Missions Division, Research and Scientific Support Department of ESA, ESTEC, Postbus 299, 2200 AG Noordwijk, The Netherlands
9 European Southern Observatory, Karl-Schwarzschild str. 2, 85748 Garching, Germany
10 European Southern Observatory, Av. Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago 19, Chile
11 INAF - Osservatorio Astronomico di Brera, via Bianchi 46, 23807 Merate (Lc), Italy
Accepted: 7 August 2004
We report on observations aimed at searching for flux variations from the proposed IR counterpart of the Anomalous X-ray Pulsar (AXP) XTE J1810-197. These data, obtained in March 2004 with the adaptive optics camera NAOS-CONICA at the ESO VLT, show that the candidate proposed by Israel et al. ([CITE], ApJ, 603, L97) was fainter by and with respect to October 2003, confirming it as the IR counterpart of XTE J1810-197. We also report on an XMM-Newton observation carried out the day before the VLT observations. The 0.5-10 keV absorbed flux of the source was erg cm-2 s-1, which is less by a factor of about two compared to the previous XMM-Newton observation on September 2003. Therefore, we conclude that a similar flux decrease took place in the X-ray and IR bands. We briefly discuss these results in the framework of the proposed mechanism(s) responsible for the IR variable emission of AXPs.
Key words: stars: pulsars: individual: XTE J1810–197 / stars: neutron / X-rays: stars
© ESO, 2004
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.