Start year
1997
Organizational Unit
Organizing institutions
Grants related:
General
Description
Accreting black-holes and neutron stars in X-ray binaries provide an ideal laboratory for exploring the physics of compact objects, yielding not only confirmation of the existence of stellar mass black holes via dynamical mass measurements, but also the best opportunity for probing high-gravity environments and the physics of accretion; the most efficient form of energy production known. The latter is an essential physical process to understand the universe, playing a crucial role in galactic and extra-galactic astronomy.
This project has the following scientific goals:
- X-ray binaries offer the opportunity to study accretion as its best, since their relevant changes occur on convenient time-scales for human beings. This project focuses on the universal relation between black-hole accretion and ejection processes in the form of collimated jets and wide-angle winds. We will focus on the general properties and astrophysical impact of the cold optical accretion disc wind that our group has discovered. We want to understand how frequent these winds are, which is their impact in the black-hole accretion process, and what is their relation with jets and hot X-ray winds. Likewise, we carry out very detailed X-ray spectral studies on the different accretion states and geometries and their evolution with luminosity.
- We want to define the mass distribution of black-holes and neutron stars. Thus, we continue our contribution to one of the fundamental experiments in modern astrophysics by measuring dynamical masses in X-ray binaries. We expect to significantly improve the observed mass distribution of compact objects. This will allow testing models of supernovae explosions and close binary evolution as well as setting constraints on the equation of state of nuclear matter. We will measure masses in newly discovered or known transient X-ray binaries. In addition, we will also search for the large number of dormant X-ray binaries expected in the Galaxy and suitable for dynamical studies.
- To study the structure of accretion discs in different energy bands (optical-X rays). The high energy spectral distribution and time variability during outburst is important to constrain the eruption models and accretion disc properties (e.g. radius of advective disc) as well as to constrain the contribution of the jet to the optical and infrared emission of the system.
see group web page: https://research.iac.es/proyecto/compactos/pages/en/introduction.php
Members
Principal investigator
Montserrat
Armas Padilla
Project staff
Jorge
Casares Velázquez
Tariq
Shahbaz
Teodoro
Muñoz Darias
Manuel Ángel
Pérez Torres
Virginia Anahi
Cúneo
María Guayente
Panizo Espinar
Ignacio
González Martínez-Pais
Pablo
Rodríguez Gil
Jonay Isai
González Hernández
Collaborators
Prof.
P. Charles
Prof.
R. Fender
Prof.
P. Jonker -
Prof.
T. Marsh
Dr.
D. Steeghs
Dr.
S. Motta
Prof.
T. Belloni
Dr.
K. O'Brien
Dr.
B. Gaensicke
Prof.
J.M. Paredes
Dr.
M. Ribó
Dr.
J. Marti
Prof.
S. Campana
Dr.
P. D’Avanzo
Dr.
I. Negueruela
Dr.
J.M. Corral-Santana
Dr.
D. Russell
Prof.
Rudy Wijnands
Dr.
N. Degenaar
Dr.
A. de Ugarte
Dr.
Y. Ueda
Dr.
R.I. Hynes
María Jesús
Arevalo Morales
Josefa
Becerra González
Artemio
Herrero Davo
Garik
Israelian
Results
- Our team has led the multi-wavelength study of the two 2015 outbursts of the Black-hole transient V404 Cyg. In 2018, we published a global paper which include all the spectroscopy taken during the 1989 and 2015 campaigns.
- We have presented solid evidence for the presence of very similar wind to that found in V404 Cyg in another black hole transient, V4641 Sgr.
- We published the final paper as well as a pilot study on a novel method developed by the group. It aims at discovering and measuring masses of black hole transient in quiescence. This method has the potential of increasing the known population of these systems by a factor of three.
- We measured the mass of the neutron star in PSR J2215+5135 and found it is one of the heaviest known to date.
- We presented the first detailed study on the ultra-compact system SLX 1737-282.
Scientific activity
Related publications
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Extremely fast orbital decay of the black hole X-ray binary Nova Muscae 1991We present new medium-resolution spectroscopic observations of the black hole X-ray binary Nova Muscae 1991 taken with X-Shooter spectrograph installed at the 8.2-m VLT telescope. These observations allow us to measure the time of inferior conjunction of the secondary star with the black hole in this system that, together with previous measurementsGonzález Hernández, J. I. et al.
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22017 -
The First Simultaneous X-Ray/Radio Detection of the First Be/BH System MWC 656MWC 656 is the first known Be/black hole (BH) binary system. Be/BH binaries are important in the context of binary system evolution and sources of detectable gravitational waves because they are possible precursors of coalescing neutron star/BH binaries. X-ray observations conducted in 2013 revealed that MWC 656 is a quiescent high-mass X-rayParedes, J. M. et al.
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22017 -
PTF1 J082340.04+081936.5: A Hot Subdwarf B Star with a Low-mass White Dwarf Companion in an 87-minute OrbitWe present the discovery of the hot subdwarf B star (sdB) binary PTF1 J082340.04+081936.5. The system has an orbital period of {P}{orb} = 87.49668(1) minutes (0.060761584(10) days), making it the second-most compact sdB binary known. The light curve shows ellipsoidal variations. Under the assumption that the sdB primary is synchronized with theKupfer, T. et al.
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22017 -
System mass constraints for the accreting millisecond pulsar XTE J1814-338 using Bowen fluorescenceWe present phase-resolved spectroscopy of the millisecond X-ray pulsar XTE J1814-338 obtained during its 2003 outburst. The spectra are dominated by high-excitation emission lines of He II λ4686, Hβ, and the Bowen blend C III/N III 4630-50 Å. We exploit the proven Bowen fluorescence technique to establish a complete set of dynamical systemWang, L. et al.
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42017 -
A millisecond pulsar candidate in a 21-h orbit: 3FGL J0212.1+5320We present the discovery of a variable optical counterpart to the unidentified gamma-ray source 3FGL J0212.1+5320 and argue that this is a new compact binary millisecond pulsar (MSP) candidate. We show 3FGL J0212.1+5320 hosts a semidetached binary with a 0.869 55 ± 0.000 15 d orbital period and an F6-type companion star at an estimated distance ofLinares, M. et al.
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32017 -
Hunting for eclipses: high-speed observations of cataclysmic variablesWe present new time-resolved photometry of 74 cataclysmic variables (CVs), 47 of which are eclipsing. Thirteen of these eclipsing systems are newly discovered. For all 47 eclipsing systems, we show high cadence (1-20 s) light curves obtained with the high-speed cameras ULTRACAM and ULTRASPEC. We provide new or refined ephemerides, and supply midHardy, L. K. et al.
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32017 -
Evidence of asymmetries in the Aldebaran photosphere from multiwavelength lunar occultationsWe have recorded three lunar occultations of Aldebaran (α Tau) at different telescopes and using various band-passes, from the ultraviolet to the far red. The data have been analysed using both model-dependent and model-independent methods. The derived uniform-disc angular diameter values have been converted to limb-darkened values using modelRichichi, A. et al.
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12017 -
The puzzling orbital period evolution of the LMXB AX J1745.6-2901The orbital period evolution of X-ray binaries provides fundamental clues to understanding mechanisms of angular momentum transfer and loss in these systems. We present an X-ray eclipse timing analysis of the transient low-mass X-ray binary AX J1745.6-2901. This system shows full eclipses and thus is one of the few objects of this class for whichPonti, G. et al.
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12017 -
Using Gaussian processes to model light curves in the presence of flickering: the eclipsing cataclysmic variable ASASSN-14agThe majority of cataclysmic variable (CV) stars contain a stochastic noise component in their light curves, commonly referred to as flickering. This can significantly affect the morphology of CV eclipses and increases the difficulty in obtaining accurate system parameters with reliable errors through eclipse modelling. Here we introduce a newMcAllister, M. J. et al.
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12017 -
The donor of Aquila X-1 revealed by high-angular resolution near-infrared spectroscopyThe low-mass X-ray binary Aquila X-1 is one of the most active neutron star X-ray transients. Despite its relatively bright quiescent optical counterpart, the detection of its companion has been hampered by the presence of a nearby interloper star. Using the Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) on the VeryMata Sánchez, D. et al.
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12017 -
Tracing the Reverberation Lag in the Hard State of Black Hole X-Ray BinariesWe report results obtained from a systematic analysis of X-ray lags in a sample of black hole X-ray binaries, with the aim of assessing the presence of reverberation lags and studying their evolution during outburst. We used XMM-Newton and simultaneous Rossi X-ray Timing Explorer (RXTE) observations to obtain broadband energy coverage of both theDe Marco, B. et al.
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112015 -
The Historical X-ray Transient KY TrA in quiescenceWe present deep optical images of the historical X-ray Transient KY TrA in quiescence from which we confirm the identification of the counterpart reported by Murdin et al. and derive an improved position of α = 15:28:16.97 and δ = -61:52:57.8. In 2007 June we obtained I, R and V images, where the counterpart seems to be double indicating theZurita, C. et al.
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122015 -
Low-level accretion in neutron star X-ray binariesWe search the literature for reports on the spectral properties of neutron star low-mass X-ray binaries when they have accretion luminosities between 1034 and 1036 erg s-1, corresponding to roughly 0.01-1 per cent of the Eddington accretion rate for a neutron star. We found that in this luminosity range the photon index (obtained from fitting aWijnands, R. et al.
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122015 -
Fifteen years of XMM-Newton and Chandra monitoring of Sgr A★: evidence for a recent increase in the bright flaring rateWe present a study of the X-ray flaring activity of Sgr A⋆ during all the 150 XMM-Newton and Chandra observations pointed at the Milky Way centre over the last 15 years. This includes the latest XMM-Newton and Chandra campaigns devoted to monitoring the closest approach of the very red Brγ emitting object called G2. The entire data set analysedPonti, G. et al.
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122015 -
Swift J1357.2-0933: a massive black hole in the Galactic thick discSwift J1357.2-0933 is one of the shortest orbital period black hole X-ray transients. It exhibited deep optical dips together with an extremely broad H α line during outburst. We present 10.4-m Gran Telescopio Canarias (GTC) time-resolved spectroscopy during quiescence searching for donor star absorption features. The large contribution of theMata Sánchez, D. et al.
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122015 -
The evolution of the disc variability along the hard state of the black hole transient GX 339-4We report on the analysis of hard-state power spectral density function (PSD) of GX 339-4 down to the soft X-ray band, where the disc significantly contributes to the total emission. At any luminosity probed, the disc in the hard state is intrinsically more variable than in the soft state. However, the fast decrease of disc variability as aDe Marco, B. et al.
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122015 -
The binary millisecond pulsar PSR J1023+0038 during its accretion state - I. Optical variabilityWe present time-resolved optical photometry of the binary millisecond `redback' pulsar PSR J1023+0038 (=AY Sex) during its low-mass X-ray binary phase. The light curves taken between 2014 January and April show an underlying sinusoidal modulation due to the irradiated secondary star and accretion disc. We also observe superimposed rapid flaring onShahbaz, T. et al.
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112015 -
A FWHM–K2 Correlation in Black Hole TransientsWe compare {{{H}}}α emission profiles of 12 dynamically confirmed black holes (BHs) and 2 neutron star X-ray transients (SXTs) in quiescence with those of a sample of 43 Cataclysmic Variables (CVs), also quiescent. The FWHM of the {{{H}}}α line in SXTs is tightly correlated with the velocity semi-amplitude of the donor star {K}2=0.233(13){FWHM}Casares, J.
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72015 -
On the formation and evolution of the first Be star in a black hole binary MWC 656We find that the formation of MWC 656 (the first Be binary containing a black hole) involves a common envelope phase and a supernova explosion. This result supports the idea that a rapidly rotating Be star can emerge out of a common envelope phase, which is very intriguing because this evolutionary stage is thought to be too fast to lead toGrudzinska, M. et al.
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92015 -
Spectral Softening Between Outburst and Quiescence In The Neutron Star Low-Mass X-Ray Binary SAX J1750.8-2900Tracking the spectral evolution of transiently accreting neutron stars between outburst and quiescence probes relatively poorly understood accretion regimes. Such studies are challenging because they require frequent monitoring of sources with luminosities below the thresholds of current all-sky X-ray monitors. We present the analysis of over 30Allen, J. L. et al.
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32015
