135 citations · 740 across the 15 of their papers we have counts for
10 papers · 1 filter
VLT/FORS2 observations of four high-luminosity ULX candidates
M. Heida, P. G. Jonker, M. A. P. Torres +4
We obtained VLT/FORS2 spectra of the optical counterparts of four high-luminosity (L_X >= 10^40 erg/s) ULX candidates from the catalog of Walton (2011). We first determined accurat…
IGR J19308+0530: Roche lobe overflow on to a compact object from a donor 1.8 times as massive
E. M. Ratti, T. F. J. van Grunsven, M. A. P. Torres +6
We present phase-resolved spectroscopy and photometry of the optical counterpart to the X-ray binary IGR J19308+0530. Ellipsoidal modulations in the light curve show that the F-typ…
CXOGBSJ174444.7-260330: a new long orbital period cataclysmic variable in a low state
E. M. Ratti, T. F. J. van Grunsven, P. G. Jonker +12
We present phase-resolved spectroscopy and photometry of a source discovered with the Chandra Galactic Bulge Survey (GBS), CXOGBSJ174444.7-260330 (aka CX93 and CX153 in the previou…
The nature of the bright ULX X-2 in NGC3921: a Chandra position and HST candidate counterpart
P. G. Jonker, M. Heida, M. A. P. Torres +6
We report on Chandra observations of the bright ultra-luminous X-ray (ULX) source in NGC3921. Previous XMM observations reported in the literature show the presence of a bright ULX…
The black hole candidate XTE J1752-223 towards and in quiescence: optical and simultaneous X-ray - radio observations
E. M. Ratti, P. G. Jonker, J. C. A. Miller-Jones +10
We present optical, X-ray and radio observations of the black hole transient (BHT) XTE J1752-223 towards and in quiescence. Optical photometry shows that the quiescent magnitude of…
On the harmonics of the low-frequency quasi-periodic oscillation in GRS 1915+105
E. M. Ratti, T. M. Belloni, S. E. Motta
GRS 1915+105 is a widely studied black hole binary, well known because of its extremely fast and complex variability. Flaring periods of high variability alternate with "stable" ph…
Optical spectroscopy of the quiescent counterpart to EXO 0748-676: a Black Widow scenario?
E. M. Ratti, D. T. H. Steeghs, P. G. Jonker +3
We present phase-resolved optical spectroscopy of the counterpart to the neutron star low mass X-ray binary EXO 0748-676, almost one year after it turned into quiescence. The spect…
An accurate position for the black hole candidate XTE J1752-223: re-interpretation of the VLBI data
J. C. A. Miller-Jones, P. G. Jonker, E. M. Ratti +4
Using high-precision astrometric optical observations from the Walter Baade Magellan Telescope in conjunction with high-resolution very long baseline interferometric (VLBI) radio i…
The Galactic Bulge Survey: outline and X-ray observations
P. G. Jonker, C. G. Bassa, G. Nelemans +22
We introduce the Galactic Bulge Survey (GBS) and we provide the Chandra source list for the region that has been observed to date. Among the goals of the GBS are constraining the n…
Chandra localisation and optical/NIR follow-up of Galactic X-ray sources
E. M. Ratti, C. G. Bassa, M. A. P. Torres +3
We investigate a sample of eleven Galactic X-ray sources recently discovered with INTEGRAL or RXTE with the goal of identifying their optical and/or near-infrared (NIR) counterpart…