Subvenciones relacionadas:
General
Los agujeros negros y estrellas de neutrones en binarias de rayos-X son laboratorios únicos para explorar la física de estos objetos compactos. No solo permiten confirmar la existencia de agujeros negros de origen estelar a través de mediciones dinámicas de sus masas, sino que también permiten investigar el comportamiento de la materia y la radiación bajo la influencia de un campo gravitatorio extremo. De este modo, es posible estudiar la física del proceso de acreción, la forma más eficiente de producción de energía conocida. El conocimiento de este proceso es esencial para entender el Universo, jugando un papel crucial en la astronomía galáctica y extra-galáctica.
Los objetivos científicos que se persiguen son:
- Estudios de acreción y eyección. Esta línea explota una fenomenología que nuestro grupo ha descubierto recientemente y se enfoca en la relación universal existente entre el proceso de acreción en agujeros negros y los procesos de expulsión en forma de jets colimados y vientos. Se pondrá énfasis en las propiedades generales y el efecto que el viento frío que hemos descubierto en binarias de rayos-X tiene sobre todo el proceso de acreción. Investigaremos como de comunes son estos vientos, como afectan al proceso de acrecimiento en el agujero negro y cuál es su relación con los jets y los vientos observados en rayos-X. Asimismo se realizarán estudios espectrales detallados en rayos X, con el fin de caracterizar los diferentes estados y geometrías de acreción en función de la luminosidad.
- Tenemos como objetivo definir la distribución de masas de agujeros negros estelares y estrellas de neutrones. Para ello medimos masas en binarias de rayos-X, continuando así nuestra ya reconocida contribución a uno de los experimentos fundamentales en la astrofísica moderna. De este modo, esperamos mejorar significativamente las distribuciones conocidas de objetos compactos, lo cual permitirá verificar modelos de explosión de supernovas y evolución de binarias compactas; además de obtener límites a la ecuación de estado de la materia nuclear. Para ello, mediremos las masas en binarias de rayos-X conocidas o recientemente descubiertas, e intentaremos encontrar un gran número de nuevas binarias de rayos X en nuestra galaxia que puedan después ser estudiadas dinámicamente.
- Analizar la estructura y variabilidad de los discos de acreción alrededor de los objetos compactos en diferentes bandas espectrales (óptico-rayos X). La distribución espectral durante la erupción (especialmente a altas energías) y su variación temporal es esencial para restringir los modelos de erupción y la estructura física del disco (e.g. radio del disco advectivo) así como la contribución del jet a la emisión en el visible y el infrarrojo.
Miembros
Resultados
- Nuestro equipo ha liderado un ambicioso estudio multi-frecuencia que cubrió las dos erupciones de 2015 del agujero negro transitorio V404 Cyg. Este evento ha sido uno de los más interesantes jamás observados de este tipo. En 2018 publicamos el trabajo global que recoge todos los datos espectroscópicos tomados en 1989 y 2015.
- Presentamos la evidencia de viento similar al detectado en V404 Cyg en un segundo sistema con agujero negro, V4641 Sgr.
- Se publicó tanto el artículo final como un estudio piloto sobre el método desarrollado por el grupo para descubrir y medir masas en agujeros negros en quietud. Esta técnica, potencialmente, podría triplicar la población conocida de estos objetos.
- Se medió la masa de la estrella de neutrones en PSR J2215+5135, una de las más masivas que se conocen hasta la fecha.
- Se presentó el primer estudio detallado del sistema ultra-compacto SLX 1737-282.
Actividad científica
Publicaciones relacionadas
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The optical counterpart of the bright X-ray transient Swift J1745-26We present a 30-day monitoring campaign of the optical counterpart of the bright X-ray transient Swift J1745-26, starting only 19 min after the discovery of the source. We observe the system peaking at i' ˜ 17.6 on day six (MJD 561 92) to then decay at a rate of ˜0.04 mag d-1. We show that the optical peak occurs at least 3 d later than the hard XMuñoz-Darias, T. et al.
Fecha de publicación:
62013 -
Broad iron line in the fast spinning neutron-star system 4U 1636-53We analysed the X-ray spectra of six observations, simultaneously taken with XMM-Newton and Rossi X-ray Timing Explorer (RXTE), of the neutron-star low-mass X-ray binary 4U 1636-53. The observations cover several states of the source, and therefore a large range of inferred mass accretion rate. These six observations show a broad emission line inSanna, Andrea et al.
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62013 -
A 2 h periodic variation in the low-mass X-ray binary Ser X-1Spectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ≃2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that theCornelisse, R. et al.
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62013 -
An Evolving Compact Jet in the Black Hole X-Ray Binary MAXI J1836–194We report striking changes in the broadband spectrum of the compact jet of the black hole transient MAXI J1836–194 over state transitions during its discovery outburst in 2011. A fading of the optical-infrared (IR) flux occurred as the source entered the hard-intermediate state, followed by a brightening as it returned to the hard state. TheRussell, D. M. et al.
Fecha de publicación:
52013 -
Observational constraints on the powering mechanism of transient relativistic jetsWe revisit the paradigm of the dependence of jet power on black hole (BH) spin in accreting BH systems. In a previous paper, we showed that the luminosity of compact jets continuously launched due to accretion on to BHs in X-ray binaries (analogous to those that dominate the kinetic feedback from active galactic nuclei) does not appear to correlateFender, R. P. et al.
Fecha de publicación:
52013 -
A Black Hole Nova Obscured by an Inner Disk Torus.Stellar-mass black holes (BHs) are mostly found in X-ray transients, a subclass of X-ray binaries that exhibit violent outbursts. None of the 50 Galactic BHs known show eclipses, which is surprising for a random distribution of inclinations. Swift J1357.2-0933 is a very faint X-ray transient detected in 2011. On the basis of spectroscopic evidenceCorral-Santana, J. M. et al.
Fecha de publicación:
32013 -
Multiwavelength spectral evolution during the 2011 outburst of the very faint X-ray transient Swift J1357.2-0933We report our multiwavelength study of the 2011 outburst evolution of the newly discovered black hole candidate X-ray binary Swift J1357.2-0933. We analysed the Swift X-ray Telescope and Ultraviolet/Optical Telescope (UVOT) data taken during the ˜7 months duration of the outburst. It displayed a 2-10 keV X-ray peak luminosity of ˜1035(D/1.5 kpc)2Wijnands, R. et al.
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22013 -
Jet spectral breaks in black hole X-ray binariesIn X-ray binaries, compact jets are known to commonly radiate at radio to infrared frequencies, whereas at optical to γ-ray energies, the contribution of the jet is debated. The total luminosity, and hence power of the jet, is critically dependent on the position of the break in its spectrum, between optically thick (self-absorbed) and opticallyGandhi, P. et al.
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22013 -
A complex state transition from the black hole candidate Swift J1753.5-0127We present our monitoring campaign of the outburst of the black hole candidate Swift J1753.5-0127, observed with the Rossi X-ray Timing Explorer and the Swift satellites. After ˜4.5 yr since its discovery, the source had a transition to the hard intermediate state. We performed spectral and timing studies of the transition showing that, unlike thevan der Klis, M. et al.
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22013 -
Quiescent X-ray/optical counterparts of the black hole transient H 1705-250We report the result of a new Chandra observation of the black hole X-ray transient H 1705-250 in quiescence. H 1705-250 was barely detected in the new ˜50 ks Chandra observation. With five detected counts, we estimate the source quiescent luminosity to be LX ˜ 9.1 × 1030 erg s-1 in the 0.5-10 keV band (adopting a distance of 8.6 kpc). This valueWijnands, R. et al.
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122012 -
Spectroscopic follow-up of ultraviolet-excess objects selected from the UVEX surveyWe present the results of the first spectroscopic follow-up of 132 optically blue ultraviolet (UV)-excess sources selected from the UV-Excess Survey of the Northern Galactic Plane (UVEX). The UV-excess spectra are classified into different populations and grids of model spectra are fitted to determine spectral types, temperatures, surface gravitiesVerbeek, Kars et al.
Fecha de publicación:
102012 -
A Search for the Optical Counterpart to the Magnetar CXOU J010043.1-721134After our tentative detection of an optical counterpart to CXOU J010043.1-721134 from archival Hubble Space Telescope (HST) imaging, we have followed up with further images in four bands. Unfortunately, the source originally identified is not confirmed. We provide deep photometric limits in four bands and accurate photometry of field stars aroundDurant, M. et al.
Fecha de publicación:
62008 -
Optical pulsations from the anomalous X-ray pulsar 1E1048.1-5937We present high-speed optical photometry of the anomalous X-ray pulsar 1E1048.1-5937 obtained with ULTRACAM on the 8.2-m Very Large Telescope in 2007 June. We detect 1E1048.1-5937 at a magnitude of i' = 25.3 +/- 0.2, consistent with the values found by Wang et al. and hence confirming their conclusion that the source was approximately 1mag brighterDhillon, V. S. et al.
Fecha de publicación:
32009 -
Optical/infrared observations of the X-ray burster KS1731-260 in quiescenceAims: We performed an optical/infrared study of the counterpart of the low-mass X-ray binary KS 1731-260 to test its identification and obtain information about the donor. Methods: Optical and infrared images of the counterpart of KS 1731-260 were taken in two different epochs (2001 and 2007) after the source returned to quiescence in X-rays. WeZurita, C. et al.
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32010 -
On the nature of HD 207331: a new δ Scuti variableWhile testing a Strömgren spectrophotometer attached to the 1.5 m telescope at the San Pedro Mártir observatory, Mexico, a number of A-type stars were observed, one of which, HD 207331, presented clear indications of photometric variability. CCD photometric data acquired soon after, confirmed its variability. In order to determine its pulsationFox Machado, L. et al.
Fecha de publicación:
112008 -
Disentangling jet and disc emission from the 2005 outburst of XTE J1118+480The black hole X-ray transient, XTE J1118+480, has now twice been observed in outbursts - 2000 and 2005 - and on both occasions remained in the low/hard X-ray spectral state. Here we present radio, infrared, optical, soft X-ray and hard X-ray observations of the more recent outburst. We find that the light curves have very different morphologiesBrocksopp, C. et al.
Fecha de publicación:
52010 -
Time-Resolved Optical Photometry of the Ultracompact Binary 4U 0614+091We present a detailed optical study of the ultracompact X-ray binary 4U 0614+091. We have used 63 hr of time-resolved optical photometry taken with three different telescopes (IAC80, NOT, and SPM) to search for optical modulations. The power spectra of each data set reveals sinusoidal modulations with different periods, which are not always presentShahbaz, T. et al.
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82008 -
The First Polarimetric Signatures of Infrared Jets in X-Ray BinariesWe present near-infrared linear spectropolarimetry of a sample of persistent X-ray binaries, Sco X-1, Cyg X-2, and GRS 1915+105. The slopes of the spectra are shallower than what is expected from a standard steady state accretion disk, and can be explained if the near-infrared flux contains a contribution from an optically thin jet. For the neutronShahbaz, T. et al.
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12008 -
SWIFT J1753.5-0127: A Surprising Optical/X-Ray Cross-Correlation FunctionWe have conducted simultaneous optical and X-ray observations of SWIFT J1753.5-0127 with RXTE and ULTRACAM, while the system persisted in its relatively bright low/hard state. In the cross-correlation function, we find that the optical emission, with a broad negative peak, leads the X-ray emission by a few seconds and has a smaller positive peak atDurant, Martin et al.
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72008 -
Rapid optical and X-ray timing observations of GX339-4: multicomponent optical variability in the low/hard stateA rapid timing analysis of Very Large Telescope (VLT)/ULTRACAM (optical) and RXTE (X-ray) observations of the Galactic black hole binary GX339-4 in the low/hard, post-outburst state of 2007 June is presented. The optical light curves in the r',g' and u' filters show slow (~20s) quasi-periodic variability. Upon this is superposed fast flaringGandhi, P. et al.
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102010