MACHO-96-BLG-5 was a microlensing event, observed towards the bulge of the Galaxy, with the exceptionally long duration of 970 days. The microlensing parallax fit parameters were used in the past in a likelihood analysis through which it has been possible to estimate both the distance and mass of the lens objects. This analysis has shown that the most likely mass for the MACHO-96-BLG-5 lens object is M=6+10-3 Sol with a distance in the range 0.5 kpc-2 kpc. The observed upper limits on the absolute brightness of main-sequence stars for this lens is less than 1 L_Sol so that it is a good black hole candidate. If it is so, then the black hole would accrete by interstellar medium thereby emitting in the X-ray band. Here, the analysis of a 100 ks XMM observation towards MACHO-96-BLG-5 lens position is reported. Only an upper limit to the X-ray flux from the black hole can been obtained from that deep observation allowing to costrain the black hole accretion parameter.
XMM Search For X-Rays From MACHO-96-BLG-5 Black Hole Candidate
NUCITA, Achille;DE PAOLIS, Francesco;INGROSSO, Gabriele;
2006-01-01
Abstract
MACHO-96-BLG-5 was a microlensing event, observed towards the bulge of the Galaxy, with the exceptionally long duration of 970 days. The microlensing parallax fit parameters were used in the past in a likelihood analysis through which it has been possible to estimate both the distance and mass of the lens objects. This analysis has shown that the most likely mass for the MACHO-96-BLG-5 lens object is M=6+10-3 Sol with a distance in the range 0.5 kpc-2 kpc. The observed upper limits on the absolute brightness of main-sequence stars for this lens is less than 1 L_Sol so that it is a good black hole candidate. If it is so, then the black hole would accrete by interstellar medium thereby emitting in the X-ray band. Here, the analysis of a 100 ks XMM observation towards MACHO-96-BLG-5 lens position is reported. Only an upper limit to the X-ray flux from the black hole can been obtained from that deep observation allowing to costrain the black hole accretion parameter.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
