6 papers
The IACOB project XVIII. Prevalence of short-period binaries among Galactic helium rich O-type stars
C. Martínez-Sebastián, R. Gamen, O. G. Benvenuto +6
For decades, the origin of helium enrichment in O-type stars has remained an open question. In this study, we investigate the correlation between surface helium abundance and orbit…
Superorbital variability in the quiescent black hole X-ray transient A0620-00
Enzo A. Saavedra, Roi Alonso, Teo Muñoz-Darias +10
Quiescent black hole low-mass X-ray binaries provide a key setting for probing accretion physics at low luminosities. A0620-00, the archetypal system in this class, has remained in…
Resolving SLX 1744-299 and SLX 1744-300 in the hard X-ray band: implications for their ultracompact nature
Enzo A. Saavedra, Montserrat Armas Padilla, Teo Muñoz-Darias
Persistent, low-luminosity low-mass X-ray binaries (LMXBs) offer a unique opportunity to study accretion in this poorly understood regime, as well as to unveil new members of the u…
A candidate proton cyclotron feature in the ultraluminous X-ray source NGC 4656 ULX-1
Nelson Cruz-Sanchez, Enzo A. Saavedra, Federico A. Fogantini +6
Ultraluminous X-ray sources represent extreme super-Eddington accretion regimes, and a subset is now known to host highly magnetized neutron stars. However, direct observational pr…
Constraints on cyclotron features and accretion regime in the high-mass X-ray binary 4U 1700-37 from NuSTAR
Lautaro West-Ocampo, Federico A. Fogantini, Enzo A. Saavedra +6
4U 1700-37 is a wind-fed high-mass X-ray binary hosting a compact object, likely a neutron star, accreting from O6.5 Iaf+ supergiant HD 153919. Coherent pulsations not firmly detec…
The hard ultraluminous state of NGC 5055 ULX X-1
N. Cruz-Sanchez, E. A. Saavedra, F. A. Fogantini +2
We present the results of the first broadband X-ray analysis of the ultraluminous X-ray source NGC 5055 ULX X-1, combining simultaneous data from XMMNewton and NuSTAR missions,…