We present archive ESO VLT photometric and spectroscopic data of the ultraluminous X-ray source NGC 1313 X-2. The superb quality of the VLT images reveals that two distinct objects, with R magnitudes 23.7 and 23.6, are visible inside the Chandra error box. The two objects, separated by 0.75", were unresolved in our previous ESO 3.6 m+EFOSC image. We show that both are stars in NGC 1313, the first a B0-O9 main-sequence star of ~20 Msolar, the second a G supergiant of ~10 Msolar. Irrespective of which of the two objects the actual counterpart is, this implies that NGC 1313 X-2 is a high-mass X-ray binary with a very massive donor.
VLT Observations of the Ultraluminous X-Ray Source NGC 1313 X-2
TUROLLA, ROBERTO;
2005
Abstract
We present archive ESO VLT photometric and spectroscopic data of the ultraluminous X-ray source NGC 1313 X-2. The superb quality of the VLT images reveals that two distinct objects, with R magnitudes 23.7 and 23.6, are visible inside the Chandra error box. The two objects, separated by 0.75", were unresolved in our previous ESO 3.6 m+EFOSC image. We show that both are stars in NGC 1313, the first a B0-O9 main-sequence star of ~20 Msolar, the second a G supergiant of ~10 Msolar. Irrespective of which of the two objects the actual counterpart is, this implies that NGC 1313 X-2 is a high-mass X-ray binary with a very massive donor.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
