radio astronomer
Born in Santander (Spain), I studied Physics at the University of Cantabria. I got my PhD
in Physics at the University of Barcelona in 2015 on the
Non-thermal emission from high-energy binaries through
interferometric radio observations. Nowadays I am Support Scientist of the European VLBI Network (EVN) at the Joint Institute
for VLBI ERIC (JIVE).
My research is mainly focused on the study of different high-energy transient sources through their radio emission.
Although I cover a variety of different fields, most of the times I am studying Galactic binary systems (such as gamma-ray
binaries, high-mass X-ray binaries or colliding wind binaries) or Fast Radio Bursts. However, I also work on the follow up
of Gravitational Wave mergers at radio frequencies. And as secondary fields I have also worked on gamma-ray bursts, continuum
emission from pulsars, or active galactic nuclei.
I typically work with very long baseline interferometric (VLBI) radio observations from the European VLBI Network
(EVN) or the Australian Long Baseline Array
(LBA). But
I also work with data at low radio frequencies (100 MHz–1 GHz) taken from the Giant Metrewave Radio Telescope
(GMRT) or the Low Frequency Array (LOFAR).
My research is focused on the study of the continuum 0.1–15 GHz radio emission of different high-energy transient sources.
On one hand, I study different kinds of Galactic binary systems, such as gamma-ray binaries, high-mass X-ray binaries or colliding wind binaries.
On the other hand, I am also focused on the study of Fast Radio Bursts through interferometric observations, and the follow up of Gravitational Wave mergers to explore
the evolution of their radio afterglows.
As side topics, I have done a few projects on gamma-ray bursts, active galactic nuclei, or continuum emission from pulsars.
I work with very long baseline interferometric (VLBI) radio observations from the European VLBI Network
(EVN) or the Australian Long Baseline Array
(LBA).
And I also work with data from more compact interferometers: at low radio frequencies (100 MHz–1 GHz) taken from the Giant Metrewave Radio Telescope
(GMRT) or the Low Frequency Array (LOFAR); and at high frequencies (1–15 GHz) with the Very Large Array (VLA) or the former Westerbork Synthesis Radio Telescope (WSRT).
Most of the stars are located in multiple systems (i.e. two or more stars orbiting between them). A tiny fraction of these
systems are composed of, at least, one massive star and another object in a very close orbit. When the second object is
either another massive star or a compact object (such as a black hole or a neutron star), a strong interaction between both
objects is observed.
In the case of systems composed of two massive stars in a close orbit, the winds of the two stars typically collide producing
a powerful region of shocked material (we call these systems as Colliding Wind Binaries). This shock acts as a particle
accelerator ejecting particles up to relativistic energies.
This collision region can be observed and studied with very high resolution radio observations, although it radiates from radio
to even gamma-rays in the most powerful cases.
Some binary systems are composed of a massive star and a compact object (which can be either a black hole or a neutron star). In these systems the wind of the massive star falls into the compact object, creating an accretion disk around it. This disk warms the material to high temperatures, producing an intense emission in X-rays. The closest material to the compact object can be accelerated and ejected out of the system, typically through the jets that are generated from the poles of the compact object. This jets are generally relativistic, expelling material that strongly radiate radiowaves.
There is a kind of binaries involving a massive star and a compact object which is even much more energetic than the previous one. In this case it is thought that the compact object is a neutron star in all cases. Though the scenario is not completely understood yet, there are clues that the strong interaction between the neutron star and the massive star avoids the accretion (as seen in X-ray Binaries), but produces a strong collision between both winds (as seen in Colliding Wind Binaries). In this case the collision is produced between the powerful wind of the massive star (usually O or B spectral type stars) and the relativistic wind of the neutron star. The exciting fact of these systems is that most of the energy is radiated as gamma-rays, requiring thus extreme energetic environments.
Fast Radio Bursts (FRBs) are objects that produce a single and bright pulse that only lasts milliseconds. The origin of these pulses remains unknown, mainly due to the limited resolution of the instruments (all of them detected with single-dish radio observations). The first FRB was discovered in 2007 by Lorimer and collaborators, and thus far 18 FRBs have been discovered. The dispersion measures observed in the pulses point to an extragalactic origin, although their origin remains unknown.
When two neutron stars or two black holes merge, a fraction of the energy in the system is liberated and emitted as gravitational waves, which
can be detected by the current instruments such as LIGO or VIRGO. In the case of neutron star mergers, a significant electromagnetic emission
(light) is expected to arise from the event. The first of these events was discovered in 2017, and a follow up involving thousands astronomers
determined the properties of such event using observations from radio wavelengths to gamma rays. I am focused on the study of the radio afterglow
(produced after the merger) on milliarcsecond scales through VLBI observations.
Paper
Constraints on the persistent radio source associated with FRB 20190520B using the European VLBI Network
Paper
Mapping Obscured Star Formation in the Host Galaxy of FRB~20201124A
Paper
Panning for gold, but finding helium: Discovery of the ultra-stripped supernova SN 2019wxt from gravitational-wave follow-up observations
Paper
Evidence for non-thermal X-ray emission from the double Wolf-Rayet colliding-wind binary Apep
Paper
A burst storm from the repeating FRB 20200120E in an M81 globular cluster
GCN Circular
GRB 221009A: radio afterglow detection with the EVN
GCN Circular
High-precision position of the compact radio counterpart to GRB221009A
Astronomer's Telegram
PRECISE detects high activity from FRB~20220912A at 1.4~GHz but no bursts at 5~GHz using the Effelsberg telescope
Paper
CASA on the fringe -- Development of VLBI processing capabilities for CASA
Paper
Astrometry of variable compact radio sources: A search for Galactic black hole X-ray binaries
Paper
Radio interferometric imaging of RS Oph bipolar ejecta for the 2021 nova outburs
Paper
VLBI observations of GRB 201015A, a relatively faint GRB with a hint of Very High Energy gamma-ray emission
Paper
MultiWavelength View of the Close-by GRB 190829A Sheds Light on Gamma-Ray Burst Physics
Paper
FRB~121102: drastic changes in the burst polarization contrasts with the stability of the persistent emission
Paper
Milliarcsecond localisation of the repeating FRB 20201124A
Astronomer's Telegram
e-EVN observations of V1674 Her
Paper
A repeating fast radio burst source in a globular cluster
Paper
Burst timescales and luminosities as links between young pulsars and fast radio bursts
Paper
Radio modelling of the brightest and most luminous non-thermal colliding-wind binary Apep
Astronomer's Telegram
Two bright bursts from FRB 20201124A with the Onsala 25-m telescope at 1.4 GHz, with no simultaneous emission detected at 330 MHz with Westerbork 25-m
Astronomer's Telegram
VLBI localization of FRB 20201124A and absence of persistent emission on milliarcsecond scales
Paper
Highly polarised microstructure from the repeating FRB 20180916B
Paper
Cygnus X-1 contains a 21-solar mass black hole -- Implications for massive star winds
Paper
LOFAR Detection of 110-188 MHz Emission and Frequency-Dependent Activity from FRB 20180916B
Paper
The 60-pc Environment of FRB 20180916B
Paper
AU-scale radio imaging of the wind collision region in the brightest and most luminous non-thermal colliding wind binary Apep
GCN Circular
GRB 201015A: 5-GHz radio afterglow detection with the EVN
GCN Circular
GRB 201015A radio afterglow with e-MERLIN
Astronomer's Telegram
VLASS constraints on the radio afterglow of the GRB afterglow/hypernova candidate SRGe J195057.5+672122
Paper
The extreme colliding-wind system Apep: resolved imagery of the central binary and dust plume in the infrared
Paper
Simultaneous X-Ray and Radio Observations of the Repeating Fast Radio Burst FRB 180916.J0158+65
Paper
VLBI20-30: a scientific roadmap for the next decade -- The future of the European VLBI Network
Astronomer's Telegram
A search for persistent radio emission and millisecond-duration radio bursts from SGR 1935+2154 using the European VLBI Network
Paper
Periodic activity from a fast radio burst source
Paper
Two Wolf-Rayet stars at the heart of colliding-wind binary Apep
Paper
A repeating fast radio burst source localized to a nearby spiral galaxy
Paper
VLBI observations of the G25.65+1.05 water maser 'Super-burst'
Paper
Probing the origin of the off-pulse emission from the pulsars B0525+21 and B2045-16
Paper
FRB 121102 Bursts Show Complex Time─Frequency Structure
Paper
Resolving the Decades-long Transient FIRST J141918.9+394036: An Orphan Long Gamma-Ray Burst or a Young Magnetar Nebula?
Paper
Compact radio emission indicates a structured jet was produced by a binary neutron star merger
Proceedings
Localizations of Fast Radio Bursts on milliarcsecond scales
Paper
Refining the origins of the gamma-ray binary 1FGL J1018.6-5856
Astronomer's Telegram
First EVN measurements of the transient FIRST J141918.9+394036 on milliarcsecond scales
Paper
Constraining very-high-energy and optical emission from FRB 121102 with the MAGIC telescopes
Paper
Science with e-ASTROGAM. A space mission for MeV-GeV gamma-ray astrophysics
Paper
Re-solving the jet/cocoon riddle of the first gravitational wave with an electromagnetic counterpart
Paper
An extreme magneto-ionic environment associated with the fast radio burst source FRB 121102
Paper
Multi-messenger Observations of a Binary Neutron Star Merger
Talk
The first localization of a Fast Radio Burst and resulting high-energy implications
GCN Circular
LIGO/Virgo G298048: Further European VLBI Network (EVN) observations of SSS17a
GCN Circular
LIGO/Virgo G298048: European VLBI Network (EVN) upper limit on 5 GHz compact emission from SSS17a
Talk
AR Scorpii, a low-mass binary with the first known radio pulsar white dwarf
Talk & proceedings
Multiwavelength emission of the gamma-ray binary LS I +61 303
Paper
Simultaneous X-ray, gamma-ray, and Radio Observations of the repeating Fast Radio Burst FRB 121102
Paper
FRB 121102 is coincident with a star forming region in its host galaxy
Talk
Localizing a Fast Radio Burst on milliarcsecond angular scales
Paper
A model for the repeating FRB 121102 in the AGN scenario
Talk
Fast Radio Bursts and their possible emission at high energies
Talk
AR Sco: the first pulsing white dwarf
Paper
Towards the origin of the radio emission in AR Scorpii, the first radio-pulsing white dwarf binary
Talk
Localizing a Fast Radio Burst for the first time
Paper
The First Simultaneous X-Ray/Radio Detection of the First Be/BH System MWC 656
Paper
The Host Galaxy and Redshift of the Repeating Fast Radio Burst FRB 121102
Paper
The Repeating Fast Radio Burst FRB 121102 as Seen on Milliarcsecond Angular Scales
Paper
A direct localization of a fast radio burst and its host
Talk
Localizing a Fast Radio Burst for the first time
Talk
On the origin of Fast Radio Bursts and sub-milliarcsecond localization
Talk
Is FRB 150418 localized in WISE J0716−19? Clues from EVN observations
Poster
The origin of the Fast Radio Bursts, still an open question
Paper
FRB 150418: clues to its nature from European VLBI Network and e-MERLIN observations
Astronomer's Telegram
EVN measurement of the FRB 150418 host galaxy candidate and its stability on VLBI scales
Astronomer's Telegram
EVN limits to compact milliarcsecond-scale radio emission from the proposed galaxy counterpart to FRB 150418
Paper
Orbital and superorbital variability of LS I +61 303 at low radio frequencies with GMRT and LOFAR
Talk
Studies on high-energy binary sources through radio observations
PhD Thesis
Non-thermal emission from high-energy binaries through interferometric radio observations
Poster
Orbital and superorbital variability of LS I +61 303 at low radio frequencies with GMRT and LOFAR
Talk
Physical properties of the gamma-ray binary LS 5039 through low- and high-frequency radio observations
Paper
Physical properties of the gamma-ray binary LS 5039 through low- and high-frequency radio observations
Paper
A radio-map of the colliding winds in the very massive binary system HD 93129A
Paper
In quest of non-thermal signatures in early-type stars
Talk
Absorption mechanisms in the gamma-ray binary LS 5039 from its full radio spectrum
Talk
Gamma-ray binaries: from low frequencies to high resolution
Talk and proceeding
Discovering the colliding wind binary HD 93129A
Poster and proceeding
The changing morphology of the radio outflow of HESS J0632+057 along its orbit
Talk
Variable Very Low Frequency Emission from the Gamma-Ray Binary LS I +61 303
Talk and proceeding
First LOFAR Observations of Gamma-Ray Binaries
Talk
The very low-frequency emission from gamma-ray binaries
Talk
El cielo menos conocido... de radio a rayos gamma
Talk
An Overview of the Modern Radio Universe
Poster
First LOFAR Observations of Gamma-Ray Binaries
Poster and proceeding
First LOFAR Observations of Gamma-Ray Binaries
Master Thesis
Low-frequency radio observations of gamma-ray binaries
Bachelor Thesis
Emisión en Rayos X de galaxias cercanas
Text (Spanish)
Universo primitivo: etapa inflacionaria
Text (Spanish)
Efecto del Sol sobre la atmósfera terrestre
Text (Spanish)
Apuntes de Física Nuclear
Text (Spanish)
Tamaños y distancias del Sistema Solar
Text (Spanish)
Cosmología Cuántica y creación del Universo
Some photos taken during my travels that are available in
Flickr: (reload webpage if you don't see the images)