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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Measuring masses in low mass X-ray binaries via X-ray spectroscopy: the case of MXB 1659-298The determination of fundamental parameters in low-mass X-ray binaries (LMXBs) typically relies on measuring the radial velocity curve of the companion star through optical or near-infrared spectroscopy. It was recently suggested that high resolution X-ray spectroscopy might enable a measurement of the radial velocity curve of the compact object byPonti, G. et al.
Advertised on:
112018 -
The 1989 and 2015 outbursts of V404 Cygni: a global study of wind-related optical featuresThe black hole transient V404 Cygni exhibited a bright outburst in June 2015 that was intensively followed over a wide range of wavelengths. Our team obtained high time resolution optical spectroscopy (! ˜ ! 90 s), which included a detailed coverage of the most active phase of the event. We present a data base consisting of 651 optical spectraMata Sánchez, D. et al.
Advertised on:
122018 -
The low-luminosity accretion disc wind of the black hole transient V4641 SagittariiWe present an optical spectroscopic study of the black hole X-ray transient V4641 Sgr (=SAX J1819.3-2525) covering the 1999, 2002, and 2004 outbursts. The spectra were taken over 22 different epochs during the low-luminosity phases that follow the sharp and bright outburst peaks displayed by the system. The data reveal the frequent presence of windMuñoz-Darias, T. et al.
Advertised on:
92018 -
On the optical counterparts of radio transients and variablesWe investigate the relation between the radio (Fr) and optical (Fo) flux densities of a variety of classes of radio transients and variables, with the aim of analysing whether this information can be used, in the future, to classify such events. Using flux density values between 1 and 10 GHz and the optical bands V and R, we build a sample with aStewart, A. J. et al.
Advertised on:
92018 -
Precision Ephemerides for Gravitational-wave Searches - III. Revised system parameters of Sco X-1Neutron stars (NSs) in low-mass X-ray binaries are considered promising candidate sources of continuous gravitational waves. These NSs are typically rotating many hundreds of times a second. The process of accretion can potentially generate and support non-axisymmetric distortions to the compact object, resulting in persistent emission ofMarsh, T. et al.
Advertised on:
82018 -
Characterization of a candidate dual AGNWe present Chandra and optical observations of a candidate dual active galactic nucleus (AGN) discovered serendipitously while searching for recoiling black holes via a cross-correlation between the serendipitous XMM source catalogue (2XMMi) and SDSS-DR7 galaxies with a separation no larger than 10 times the sum of their Petrosian radii. The systemLena, D. et al.
Advertised on:
72018 -
Peering into the Dark Side: Magnesium Lines Establish a Massive Neutron Star in PSR J2215+5135New millisecond pulsars (MSPs) in compact binaries provide a good opportunity to search for the most massive neutron stars. Their main-sequence companion stars are often strongly irradiated by the pulsar, displacing the effective center of light from their barycenter and making mass measurements uncertain. We present a series of opticalLinares, M. et al.
Advertised on:
52018 -
Flickering in AGB stars: probing the nature of accreting companionsBinary companions to asymptotic giant branch (AGB) stars are an important aspect of their evolution. Few AGB companions have been detected, and in most cases it is difficult to distinguish between main-sequence and white dwarf companions. Detection of photometric flickering, a tracer of compact accretion discs around white dwarfs, can help identifySnaid, S. et al.
Advertised on:
72018 -
Evidence for hot clumpy accretion flow in the transitional millisecond pulsar PSR J1023+0038We present simultaneous optical and near-infrared (IR) photometry of the millisecond pulsar PSR J1023+0038 during its low-mass X-ray binary phase. The r΄- and Ks-band light curves show rectangular, flat-bottomed dips, similar to the X-ray mode-switching (active-passive state transitions) behaviour observed previously. The cross-correlation functionShahbaz, T. et al.
Advertised on:
62018 -
The sdB pulsating star V391 Peg and its putative giant planet revisited after 13 years of time-series photometric dataV391 Peg (alias HS 2201+2610) is a subdwarf B (sdB) pulsating star that shows both p- and g-modes. By studying the arrival times of the p-mode maxima and minima through the O-C method, in a previous article the presence of a planet was inferred with an orbital period of 3.2 years and a minimum mass of 3.2 MJup. Here we present an updated O-CMolnar, L. et al.
Advertised on:
42018 -
280 one-opposition near-Earth asteroids recovered by the EURONEAR with the Isaac Newton TelescopeContext. One-opposition near-Earth asteroids (NEAs) are growing in number, and they must be recovered to prevent loss and mismatch risk, and to improve their orbits, as they are likely to be too faint for detection in shallow surveys at future apparitions. Aims: We aimed to recover more than half of the one-opposition NEAs recommended forVaduvescu, O. et al.
Advertised on:
12018 -
The SUrvey for Pulsars and Extragalactic Radio Bursts - II. New FRB discoveries and their follow-upWe report the discovery of four Fast Radio Bursts (FRBs) in the ongoing SUrvey for Pulsars and Extragalactic Radio Bursts at the Parkes Radio Telescope: FRBs 150610, 151206, 151230 and 160102. Our real-time discoveries have enabled us to conduct extensive, rapid multimessenger follow-up at 12 major facilities sensitive to radio, optical, X-rayBhandari, S. et al.
Advertised on:
42018 -
NuSTAR + XMM-Newton monitoring of the neutron star transient AX J1745.6-2901AX J1745.6-2901 is a high-inclination (eclipsing) transient neutron star (NS) low-mass X-ray binary showcasing intense ionized Fe K absorption. We present here the analysis of 11 XMM-Newton and 15 NuSTAR new data sets (obtained between 2013 and 2016), therefore tripling the number of observations of AX J1745.6-2901 in outburst. Thanks toPonti, G. et al.
Advertised on:
12018 -
The very faint hard state of the persistent neutron star X-ray binary SLX 1737-282 near the Galactic CentreWe report on a detailed study of the spectral and temporal properties of the neutron star low-mass X-ray binary SLX 1737-282, which is located only ∼1° away from Sgr A*. The system is expected to have a short orbital period, even within the ultracompact regime, given its persistent nature at low X-ray luminosities and the long durationArmas Padilla, M. et al.
Advertised on:
12018 -
Hibernating black holes revealed by photometric mass functionsWe present a novel strategy to uncover the Galactic population of quiescent black holes (BHs). This is based on a new concept, the photometric mass function (PMF), which opens up the possibility of an efficient identification of dynamical BHs in large fields-of-view. This exploits the width of the disc H α emission line, combined with orbitalCasares, J.
Advertised on:
22018 -
Bowen emission from Aquila X-1: evidence for multiple components and constraint on the accretion disc vertical structureWe present a detailed spectroscopic study of the optical counterpart of the neutron star X-ray transient Aquila X-1 during its 2011, 2013 and 2016 outbursts. We use 65 intermediate resolution GTC-10.4 m spectra with the aim of detecting irradiation-induced Bowen blend emission from the donor star. While Gaussian fitting does not yield conclusiveJiménez-Ibarra, F. et al.
Advertised on:
32018 -
The long-term optical evolution of the black hole candidate MAXI J1659-152We present 5 yr of optical and infrared data of the black hole candidate MAXI J1659-152 covering its 2010 outburst, decay, and quiescence. Combining optical data taken during the outburst decay, we obtain an orbital period of 2.414 ± 0.005 h, in perfect agreement with the value previously measured from X-ray dips. In addition, we detect a clear H αCorral-Santana, J. M. et al.
Advertised on:
32018 -
Paving the way to simultaneous multi-wavelength astronomyWhilst astronomy as a science is historically founded on observations at optical wavelengths, studying the Universe in other bands has yielded remarkable discoveries, from pulsars in the radio, signatures of the Big Bang at submm wavelengths, through to high energy emission from accreting, gravitationally-compact objects and the discovery of gammaMiddleton, M. J. et al.
Advertised on:
112017 -
Photoionization instability of the Fe K absorbing plasma in the neutron star transient AX J1745.6-2901AX J1745.6-2901 is a low-mass X-ray binary with an accreting neutron star, showing clear evidence for highly ionized absorption. Strong ionized Fe Kα and Kβ absorption lines are always observed during the soft state, whereas they disappear during the hard state. We computed photoionization stability curves for the hard and the soft states, underBianchi, S. et al.
Advertised on:
122017 -
A search for optical bursts from the repeating fast radio burst FRB 121102We present a search for optical bursts from the repeating fast radio burst FRB 121102 using simultaneous observations with the high-speed optical camera ULTRASPEC on the 2.4-m Thai National Telescope and radio observations with the 100-m Effelsberg Radio Telescope. A total of 13 radio bursts were detected, but we found no evidence for correspondingHardy, L. K. et al.
Advertised on:
122017
