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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Rapid optical and X-ray timing observations of GX 339-4: flux correlations at the onset of a low/hard stateWe present the discovery of optical/X-ray flux correlations on rapid time-scales in the low/hard state of the Galactic black hole GX339-4. The source had recently emerged from outburst and was associated with a relatively faint counterpart with mag V ~ 17. The optical [Very Large Telescope (VLT)/ULTRACAM] and X-ray (Rossi X-ray Timing Explorer)Gandhi, P. et al.
Advertised on:
102008 -
Multiwavelength spectral and high time resolution observations of SWIFTJ1753.5-0127: new activity?We have conducted an extensive observational campaign of SWIFTJ1753.5-0127 during 2007 June after its bright outburst episode in 2005. We have performed multiband optical photometry, optical spectroscopy, X-ray spectroscopy and timing and ULTRACAM optical photometry simultaneously in three bands. Both the optical spectrum and the X-ray spectrumDurant, M. et al.
Advertised on:
12009 -
GX 9+9: Variability of the X-Ray Orbital ModulationResults of observations of the Galactic bulge X-ray source GX 9+9 by the All-Sky Monitor (ASM) and Proportional Counter Array (PCA) onboard the Rossi X-ray Timing Explorer are presented. The ASM results show that the 4.19 hr X-ray periodicity first reported by Hertz and Wood in 1987 was weak or not detected for most of the mission prior to lateHarris, Robert J. et al.
Advertised on:
52009 -
The near-infrared counterpart of 4U 1636-53Context. The optical counterpart of the neutron star X-ray binary and well known X-ray burster, 4U 1636-53 (=4U 1636-536 = V801 Ara) has been studied for three decades. However, no infrared studies have been reported to date. Aims: Our aims are to identify and investigate the near-infrared (NIR) counterpart of 4U 1636-53. Methods: We present deepRussell, D. M. et al.
Advertised on:
32012 -
Polarimetry of the transient relativistic jet of GRB 110328/Swift J164449.3+573451We present deep infrared (Ks-band) imaging polarimetry and radio (1.4- and 4.8-GHz) polarimetry of the enigmatic transient Swift J164449.3+573451. This source appears to be a short-lived jet phenomenon in a galaxy at redshift z= 0.354, activated by a sudden mass accretion on to the central massive black hole, possibly caused by the tidal disruptionWiersema, K. et al.
Advertised on:
42012 -
Optical and near-infrared spectroscopy of the black hole GX 339-4 - I. A focus on the continuum in the low/hard and high/soft statesThe microquasar GX 339-4, known to exhibit powerful compact jets that dominate its radio to near-infrared emission, entered an outburst in 2010 for the fifth time in about 15 yr. An extensive radio to X-ray multiwavelength campaign was immediately triggered, and we report here on European Southern Observatory/FORS2+ISAAC optical and near-infraredRahoui, F. et al.
Advertised on:
52012 -
Flares from a candidate Galactic magnetar suggest a missing link to dim isolated neutron starsMagnetars are young neutron stars with very strong magnetic fields of the order of 1014-1015G. They are detected in our Galaxy either as soft γ-ray repeaters or anomalous X-ray pulsars. Soft γ-ray repeaters are a rare type of γ-ray transient sources that are occasionally detected as bursters in the high-energy sky. No optical counterpart to the γCastro-Tirado, A. J. et al.
Advertised on:
92008 -
Observational properties of accretion discs: Precessing and warped?Over the last 40 years, X-ray astronomy missions have revealed long-term, superorbital periods in a variety of X-ray binaries. These modulations can provide significant constraints on the physical properties of accretion discs. Some of these modulations are Her X-1-like and are interpreted as irradiation-driven, tilted, precessing accretion discsCharles, Phil et al.
Advertised on:
52008 -
Decade time-scale modulation of low-mass X-ray binariesRegular observations by the All-Sky Monitor aboard the Rossi X-ray Timing Explorer satellite have yielded well-sampled light curves with a time baseline of over 10 years. We find that up to eight of the 16 brightest persistent low-mass X-ray binaries (LMXBs) show significant, possible sinusoidal, variations with periods of the order of 10 years. WeDurant, M. et al.
Advertised on:
12010 -
Correlated optical/X-ray long-term variability in LMXB 4U 1636-536We have conducted a 3-month programme of simultaneous optical, soft and hard X-ray monitoring of the LMXB 4U 1636-536/V801 Ara using the SMARTS 1.3-m telescope and archival RXTE/ASM and Swift/XRT data. 4U 1636-536 has been exhibiting a large amplitude, quasi-periodic variability since 2002 when its X-ray flux dramatically declined by roughly anShih, I. C. et al.
Advertised on:
32011 -
Combined Chandra, XMM-Newton, and Hubble Space Telescope observations of the Galactic globular cluster NGC 2808Aims: Using new Chandra X-ray observations and existing XMM-Newton X-ray and Hubble far ultraviolet observations, we aim to detect and identify the faint X-ray sources belonging to the Galactic globular cluster NGC 2808 in order to understand their role in the evolution of globular clusters. Methods: We present a Chandra X-ray observation of theServillat, M. et al.
Advertised on:
112008 -
The quiescent spectral energy distribution of V404 CygWe present a multiwavelength study of the black hole X-ray binary V404 Cyg in quiescence, focusing upon the spectral energy distribution (SED). Radio, optical, ultraviolet (UV) and X-ray coverage is simultaneous. We supplement the SED with additional non-simultaneous data in the optical through infrared where necessary. The compiled SED is the mostHynes, R. I. et al.
Advertised on:
112009 -
The optical counterparts of accreting millisecond X-ray pulsars during quiescenceContext: Eight accreting millisecond X-ray pulsars (AMXPs) are known to date. Although these systems are well studied at high energies, very little information is available for their optical/NIR counterparts. Up to now, only two of them, SAX J1808.4-3658 and IGR J00291+5934, have a secure multi-band detection of their optical counterparts inD'Avanzo, P. et al.
Advertised on:
122009 -
The nature of the X-ray transient MAXI J0556-332Phase-resolved spectroscopy of the newly discovered X-ray transient MAXI J0556-332 has revealed the presence of narrow emission lines in the Bowen region that most likely arise on the surface of the mass donor star in this low-mass X-ray binary. A period search of the radial velocities of these lines provides two candidate orbital periods (16.43 ±Cornelisse, R. et al.
Advertised on:
32012 -
The Fast Spiral-in of the Companion Star to the Black Hole XTE J1118+480We report the detection of an orbital period decay of dot{P}=-1.83+/- 0.66 ms yr-1 in the black hole X-ray binary XTE J1118+480. This corresponds to a period change of -0.85 ± 0.30 μs per orbital cycle, which is ~150 times larger than expected from the emission of gravitational waves. These observations cannot be reproduced by conventional modelsGonzález-Hernández, J. I. et al.
Advertised on:
12012 -
Swift J1753.5-0127: The Black Hole Candidate with the Shortest Orbital PeriodWe present time-resolved photometry of the optical counterpart to the black hole candidate Swift J1753.5-0127 which has remained in the low/hard X-ray state and bright at optical/IR wavelengths since its discovery in 2005. At the time of our observations Swift J1753.5-0127 does not show a decay trend but remains stable at R=16.45 with a night-toZurita, C. et al.
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72008 -
Refined Orbital Solution and Quiescent Variability in the Black Hole Transient GS 1354-64 (= BW Cir)In Casares et al. we presented the first radial velocity curve of the companion star to BW Cir which demonstrates the presence of a black hole in this historical X-ray transient. But these data were affected by aliasing and two possible periods at 2.5445 days and 2.5635 days were equally possible. Here we present new spectroscopic data that enableCasares, J. et al.
Advertised on:
32009 -
Phase-resolved spectroscopy of the accreting millisecond X-ray pulsar SAX J1808.4-3658 during the 2008 outburstAims: We obtained phase-resolved spectroscopy of the accreting millisecond X-ray pulsar SAX J1808.4-3658 during its outburst in 2008 to find a signature of the donor star, constrain its radial velocity semi-amplitude (K_2), and derive estimates for the pulsar mass. Methods: Using Doppler images of the Bowen region, we find a significant (≥8σ)Cornelisse, R. et al.
Advertised on:
22009 -
On the masses and evolutionary status of the black hole binary GX 339-4: a twin system of XTE J1550-564?We apply the K-correction to the black hole low-mass X-ray binary (LMXB) GX 339-4 which implies MX >= 6Msolar by only assuming that the companion is more massive than ~0.17Msolar, the lower limit allowed by applying a `stripped-giant' model. This evolutionary model successfully reproduces the observed properties of the system. We obtain a maximumMuñoz-Darias, T. et al.
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42008 -
On the mass of the neutron star in Cyg X-2We present new high-resolution spectroscopy of the low-mass X-ray binary Cyg X-2, which enables us to refine the orbital solution and rotational broadening of the donor star. In contrast with Elebert et al., we find a good agreement with results reported in Casares et al. We measure P = 9.84450 +/- 0.00019 d, K2 = 86.5 +/- 1.2 kms-1 and V sini = 33Casares, J. et al.
Advertised on:
22010
