A5054213397- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Mechanics and Biomechanics Studies
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- CCD and CMOS Imaging Sensors
- High-pressure geophysics and materials
- Astro and Planetary Science
- Cardiovascular Disease and Adiposity
- Astronomical Observations and Instrumentation
- Particle Accelerators and Free-Electron Lasers
- Geological and Geochemical Analysis
- Galaxies: Formation, Evolution, Phenomena
- Adaptive optics and wavefront sensing
- SAS software applications and methods
- Particle Detector Development and Performance
- Geophysics and Sensor Technology
- Particle physics theoretical and experimental studies
Instituto de Astrofísica de Canarias
2020-2024
Universidad de La Laguna
2019-2024
Abstract We report on a detailed optical spectroscopic follow-up of the black hole (BH) transient MAXI J1820+070 (ASASSN-18ey). The observations cover main part X-ray binary outburst, when source alternated between hard and soft states following classical pattern widely seen in other systems. focus analysis He i emission lines at 5876 6678 Å, as well H α . detect clear accretion disk wind features (P-Cyg profiles broad line wings) state, both during outburst rise decay. These are not...
The black hole transient MAXI J1820+070 displayed optical P Cyg profiles and other wind-related emission line features during the hard state of its discovery outburst. We present near-infrared (NIR) spectroscopy covering different accretion states system this event. Our eight-epoch data set (VLT/X-shooter) reveals strong variability in properties NIR lines. This includes absorption troughs extended wings with kinetic that are remarkably similar to those inferred from wind signatures observed...
We present twelve epochs of optical spectroscopy taken across the discovery outburst black hole candidate MAXI J1803-298 with GTC and VLT telescopes. The source followed a standard evolution hard soft states. system displays triangular shape in hardness intensity diagram, consistent that seen high inclination transients previously reported detection X-ray dips. two observed during initial state exhibited asymmetric emission line profiles, including P-Cygni profile simultaneously detected...
GX 339–4 is one of the prototypical black hole X-ray transients, exhibiting recurrent outbursts that allow detailed studies accretion and ejection phenomena. In this work we present four epochs optical near-infrared spectroscopy obtained with X-shooter at Very Large Telescope. The dataset includes two hard state spectra, collected during 2013 2015 outbursts, soft spectra observed 2021 outburst. Strong Balmer, Paschen, He I II emission lines are consistently in all while Brackett transitions...
GX 339$-$4 is one of the prototypical black hole X-ray transients, exhibiting recurrent outbursts that allow detailed studies accretion and ejection phenomena. In this work we present four epochs optical near-infrared spectroscopy obtained with X-shooter at Very Large Telescope. The dataset includes two hard state spectra, collected during 2013 2015 outbursts, soft spectra observed 2021 outburst. Strong Balmer, Paschen, He I II emission lines are consistently in all while Brackett...
We present time-resolved Gran Telescopio Canarias optical spectroscopy and William Herschel Telescope i -band photometry of the X-ray transient SWIFT J1753.5–0127 in quiescence. The light curve is dominated by flickering with an amplitude ∼0.5 mag shows no evidence ellipsoidal modulation companion star. telluric-corrected average spectrum, on other hand, reveals presence weak (strongly veiled) TiO bands at 7055 Å 7589 Å. used them for a spectral classification, finding M4-5 V However, as...
We present time-resolved Gran Telescopio Canarias optical spectroscopy and William Herschel Telescope $i$-band photometry of the X-ray transient SWIFT J1753.5-0127 in quiescence. The light curve is dominated by flickering with an amplitude $\sim 0.5$ mag shows no evidence ellipsoidal modulation companion star. telluric-corrected average spectrum, on other hand, reveals presence weak (strongly veiled) TiO bands at $7055$ \.A $7589$ \.A. used them for a spectral classification, finding M4-5 V...
Abstract We present the discovery of an optical accretion disk wind in X-ray transient Swift J1858.6-0814. Our 90-spectrum data set, taken with 10.4 m Gran Telescopio Canarias telescope over eight different epochs and across five months, reveals presence conspicuous P-Cyg profiles He i at 5876 Å H α . These features are detected throughout entire campaign, albeit their intensity main observational properties observed to vary on timescales as short 5 minutes. In particular, we observe...
MAXI J1348–630 is a low mass X-ray binary discovered in 2019 during bright outburst. During this event, the system experienced both hard and soft states following standard evolution. We present multi-epoch optical near-infrared spectroscopy obtained with X-shooter at Very Large Telescope. Our dataset includes spectra taken brightest phases of outburst as well decay towards quiescence. study evolution main emission lines, paying special attention to presence features commonly associated...
We present simultaneous optical and near-infrared spectra obtained during the 2021 outburst of black hole transient 4U 1543–47. The X-ray hardness-intensity diagram comparison with similar systems reveal a luminous outburst, probably reaching Eddington luminosity, as well long-lasting excursion to so-called ultra-luminous state. VLT/X-shooter were taken in two epochs 14 days apart early brightest part while source was this accretion data show strong H He I emission lines, high-excitation II...
We present a new method to derive binary inclinations in quiescent black hole (BH) X-ray transients (XRTs), based on the depth of trough (T) from double-peaked Ha emission profiles arising accretion discs. find that inclination angle (i) is linearly correlated with T phase-averaged spectra sufficient orbital coverage (>~50 per cent) and spectral resolution, following i (deg)=93.5 x +23.7. The correlation caused by combination line opacity local broadening, where leading (excess broadening)...
We present optical spectroscopy obtained with the GTC, VLT and SALT telescopes during decline of 2016-2017 outburst black hole candidate GRS 1716-249 (Nova Oph 1993). Our 18-epoch data set spans 6 months reveals that observational properties main emission lines are very variable, even on time scales a few hours. Several epochs characterised by P-Cyg (as well as flat-top asymmetric) profiles in H$\alpha$, H$\beta$ He II ($\lambda$4686) lines, implying presence an accretion disc wind, which is...
The black hole transient GRS 1915+105 entered a new phase of activity in 2018, generally characterised by low X-ray and radio fluxes. This has only been interrupted episodes strong variable emission, where high levels absorption local to the source were measured. We present 18 epochs near-infrared spectroscopy (2018–2023) obtained with GTC/EMIR VLT/X-shooter, spanning both radio-loud radio-quiet periods. demonstrate that phases are P-Cygni line profiles, indicative accretion disc winds...
We present a dynamical study of the intermediate polar cataclysmic variable YY Dra based on time-series observations in K band, where donor star is known to be major flux contributor. covered 3.97-h orbital cycle with 44 spectra taken between 2020 and 2022 two epochs photometry observed 2021 March May. One light curves was simultaneously obtained spectroscopy better account for effects irradiation presence accretion light. From spectroscopy, we derived radial velocity curve metallic...
ABSTRACT We report on the first simultaneous high-time resolution X-ray and infrared (IR) observations of a neutron star low mass binary in its hard state. performed $\approx 2\,$ h 4U 1728−34 using HAWK-I@VLT, XMM–Newton, NuSTAR. The source displayed significant IR variability down to sub-second time-scales. By measuring cross-correlation function between lightcurves, we discovered correlation with an lead 30 \!-\! 40\,$ ms respect X-rays. analysed energy dependence lag, finding marginal...
MAXI J1813-095 is an X-ray transient discovered during outburst in 2018. We report on and optical observations obtained this event, which indicate that the source a new low-mass binary. The lasted ~70 d peaked at Lx(0.5-10keV)~7.6 x 10^36 erg s-1, assuming distance of 8 kpc. Swift/XRT follow-up covering whole activity period shows emission was always dominated by hard power-law component with photon index range 1.4-1.7. These values are consistent being state, agreement ~30 per cent...
ABSTRACT We present a dynamical study of the eclipsing intermediate polar XY Ari based on time-resolved near-infrared spectroscopy obtained with EMIR spectrograph 10.4-m Gran Telescopio Canarias. Using main sequence template spectra taken same instrument setup as target spectra, we measure radial velocity amplitude late K- type donor star K2 = 256 ± 2 km s−1. also obtain rotational broadening its photospheric lines vrot sin i 141 3 From these and eclipse geometry, derive donor-to-white dwarf...
Accreting white dwarfs are known to show signatures of wind-type outflows in the ultraviolet. However, at optical wavelengths, wind detections have only been reported for a few sources. We present GTC-10.4 m spectroscopy four accreting (BZ Cam, V751 Cyg, MV Lyr, and V425 Cas) observed during luminous epochs, when their emission is expected be dominated by accretion disc. Our analysis focuses on lines: H α He I λ 5876, 6678, 7065. Line profiles complex variable short (minutes) long (days...
Swift J1357.2-0933 is a black hole transient that of particular interest due to the optical recurrent dips found during its first two outbursts (in 2011 and 2017), which lack an obvious X-ray equivalent. We present study based on fast photometry most recent outbursts, in 2019 2021. Our observations reveal were every observed outburst source, although they shallower showed longer recurrence periods fainter events. performed global properties four do not follow common temporal evolution. In...
We present a dynamical study of the intermediate polar cataclysmic variable YY Dra based on time-series observations in $K$ band, where donor star is known to be major flux contributor. covered $3.97$-h orbital cycle with 44 spectra taken between $2020$ and $2022$ two epochs photometry observed 2021 March May. One light curves was simultaneously obtained spectroscopy better account for effects irradiation presence accretion light. From spectroscopy, we derived radial velocity curve metallic...
Among the sample of Galactic transient X-ray binaries (SXTs) discovered to date, about 70 have been proposed as likely candidates host a black hole. Yet, only 19 dynamically confirmed. Such reliable confirmation requires phase-resolved spectroscopy their companion stars, which is generally feasible when system in quiescent state. However, since most SXT population lies galactic plane, strongly affected by interstellar extinction, optical brightness during quiescence usually falls beyond...
We present simultaneous optical and near-infrared spectra obtained during the 2021 outburst of black hole transient 4U 1543-47. The X-ray hardness-intensity diagram comparison with similar systems reveal a luminous outburst, probably reaching Eddington luminosity, as well long-lasting excursion to so-called ultra-luminous state. VLT/X-shooter were taken in two epochs 14 days apart early brightest part while source was this accretion data show strong H HeI emission lines, high-excitation HeII...
We present a dynamical study of the eclipsing intermediate polar XY Ari based on time-resolved near-infrared spectroscopy obtained with EMIR spectrograph 10.4-m Gran Telescopio Canarias. Using main sequence template spectra taken same instrument setup as target spectra, we measure radial velocity amplitude late K-type donor star $K_2=256 \pm 2$ km s$^{-1}$. also obtain rotational broadening its photospheric lines $v_\mathrm{rot} \sin i = 141 3$ From these and eclipse geometry, derive...
We report on the first simultaneous high-time resolution X-ray and infrared (IR) observations of a neutron star low mass binary in its hard state. performed $\approx 2\,$h 4U 1728-34 using HAWK-I@VLT, XMM-Newton NuSTAR. The source displayed significant IR variability down to sub-second timescales. By measuring cross-correlation function between lightcurves, we discovered correlation with an lead 30-40\,$ms respect X-rays. analysed energy dependence lag, finding marginal increase towards...