312 citations · 6.5k across the 153 of their papers we have counts for
12 papers · 1 filter
X-ray and optical properties of new Gamma Cas-like objects discovered in X-ray surveys
Christian Motch, Raimundo Lopes de Oliveira, Ignacio Negueruela +2
A growing number of early Be stars discovered in X-ray surveys exhibit X-ray luminosities intermediate between those of normal stars and those of most Be/X-ray binaries in quiescen…
Blue Stragglers, Be stars and X-ray binaries in open clusters
Amparo Marco, Ignacio Negueruela, Christian Motch
Combination of high-precision photometry and spectroscopy allows the detailed study of the upper main sequence in open clusters. We are carrying out a comprehensive study of a numb…
Supergiant Fast X-ray Transients: A new class of high mass X-ray binaries unveiled by INTEGRAL
Ignacio Negueruela, David M. Smith, Pablo Reig +2
INTEGRAL monitoring of the Galactic Plane is revealing a growing number of recurrent X-ray transients, characterised by short outbursts with very fast rise times (~ tens of minutes…
Wind accretion in the massive X-ray binary 4U 2206+54: abnormally slow wind and a moderately eccentric orbit
M. Ribo, I. Negueruela, P. Blay +2
Massive X-ray binaries are usually classified depending on the properties of the donor star in classical, supergiant and Be X-ray binaries. The massive X-ray binary 4U 2206+54 does…
The optical counterpart to the peculiar X-ray transient XTE J1739-302
Ignacio Negueruela, David M. Smith, Thomas E. Harrison +1
The weak X-ray transient XTE J1739-302, characterized by extremely short outbursts, has recently been identified with a reddened star. Here we present spectroscopy and photometry o…
Multiwavelength monitoring of BD+53 2790, the optical counterpart to 4U~2206+54
P. Blay, I. Negueruela, P. Reig +4
We present the results of our long-term monitoring of BD+53 2790, the optical counterpart to the X-ray source 4U~2206+54. Unlike previous studies that classify the source as a Be/X…
A Neutron Star with a Massive Progenitor in Westerlund 1
M. P. Muno, J. S. Clark, P. A. Crowther +9
We report the discovery of an X-ray pulsar in the young, massive Galactic star cluster Westerlund 1. We detected a coherent signal from the brightest X-ray source in the cluster, C…
SXP 323 - an unusual X-ray binary system in the Small Magellanic Cloud
M. J. Coe, I. Negueruela, V. A. McBride
Spectroscopic observations taken with the VLT/UVES telescope/instrument are presented of the unusual Small Magellanic Cloud (SMC) X-ray binary system SXP 323 = AX J0051-733. This s…
Long-term optical/IR variability of the Be/X-ray binary LS V +44 17/RX J0440.9+4431
P. Reig, I. Negueruela, J. Fabregat +2
We present the first long-term study of the optical counterpart to the X-ray pulsar LS V +44 17/RX J0440.9+4431. The results of our photometric and spectroscopic analysis show that…
Identification of the optical counterparts of high-mass X-ray binaries through optical photometry and spectroscopy
P. Reig, I. Negueruela, G. Papamastorakis +2
We present the results of our search for optical counterparts to high-mass X-ray transient sources discovered by various X-ray missions. We obtained CCD images of the X-ray fields…
Further evidence for the presence of a neutron star in 4U 2206+54. INTEGRAL and VLA observations
P. Blay, M. Ribo, I. Negueruela +5
The majority of High Mass X-ray Binaries (HMXBs) behave as X-ray pulsars, revealing that they contain a magnetised neutron star. Among the four HMXBs not showing pulsations, and th…
Further Wolf-Rayet stars in the starburst cluster Westerlund 1
Ignacio Negueruela, J. Simon Clark
We present new low and intermediate-resolution spectroscopic observations of the Wolf Rayet (WR) star population in the massive starburst cluster Westerlund 1. Finding charts are p…