MACHO-96-BLG-5 was a microlensing event observed toward the bulge of the Galaxy with an exceptionally long duration of 970 days. The microlensing parallax fit parameters were used to estimate a lens massM = 6þ10 3 M, corresponding to a distance d in the range 0.5Y2 kpc. The upper limit on the absolute brightness formain-sequence stars of the same mass is less than 1 L, so the lens is a good black hole candidate. Such a black hole would accrete from the interstellar medium, thereby emitting in the X-ray band. Here we report the analysis of a deep XMM-Newton observation toward the MACHO-96-BLG-5 lens position. Only an upper limit (99.8% confidence level) to the X-ray flux fromthe lens position, 9.10 ; 1015 to 1.45 ; 1014 ergs cm2 s1 in the 0.2Y10 keVenergy band, is obtained, allowing us to constrain the putative black hole’s accretion parameters.

An XMM-Newton Search for X-Ray Emission from the Microlensing Event MACHO-96-BLG-5

NUCITA, Achille;DE PAOLIS, Francesco;INGROSSO, Gabriele;ELIA, Davide Quintino;
2006

Abstract

MACHO-96-BLG-5 was a microlensing event observed toward the bulge of the Galaxy with an exceptionally long duration of 970 days. The microlensing parallax fit parameters were used to estimate a lens massM = 6þ10 3 M, corresponding to a distance d in the range 0.5Y2 kpc. The upper limit on the absolute brightness formain-sequence stars of the same mass is less than 1 L, so the lens is a good black hole candidate. Such a black hole would accrete from the interstellar medium, thereby emitting in the X-ray band. Here we report the analysis of a deep XMM-Newton observation toward the MACHO-96-BLG-5 lens position. Only an upper limit (99.8% confidence level) to the X-ray flux fromthe lens position, 9.10 ; 1015 to 1.45 ; 1014 ergs cm2 s1 in the 0.2Y10 keVenergy band, is obtained, allowing us to constrain the putative black hole’s accretion parameters.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11587/104522
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 12
  • ???jsp.display-item.citation.isi??? 13
social impact