Nuclear, Gravitational Wave and Multi-messenger Astrophysics Department

Artist concept of Gravity Probe B orbiting the Earth to measure space-time, a four-dimensional description of the universe including height, width, length, and time. Image Credit: NASA

Nuclear Astrophysics, Gravitational Wave Astronomy and Multi-messenger Astrophysics

The primary scientific goal of this department is to do research in nuclear physics, gravitational wave physics and in multi-messenger astrophysics with the goal of understanding compact objects like neutron stars, black holes, and the nature of the gravitational interaction. To that end, we carry out observational and theoretical studies that include multi-messenger observations and the development of instrumentation. Regarding observations we mainly use, but not limited to, X-ray and gravitational waves.

Main research lines

Extreme compact objects in the transient multi-band sky

Activities focus mainly on the study of the multi-band emission of compact objects from an observational and theoretical point of view. Our work focuses on radio pulsars, their population modelling, magnetars, accreting millisecond pulsars, transitional pulsars and neutron stars and black hole X-ray binaries in general. We are involved in multi-messenger follow-up of compact binary mergers, especially related with the X-ray transient sky.

Gravitational Wave Theory

The activities of this group can be divided into three groups: (i)gravitational wave source modelling: Use of numerical relativity and approximation techniques in General Relativity and eventually modified gravitational theories for the construction of waveform models. (ii) Bayesian methods for source detection: Development of techniques (including machine learning) for the detection and physical characterization of GW sources. (iii) Studies in Astrophysics, Cosmology and Fundamental Physics for interpretation of multimessenger observations with GWs.

Nuclear & Particle Astrophysics

The NAP group aims at understanding the behavior of matter under extreme density and/or matter conditions. We mainly focus on understanding the physics of compact stellar objects from its tiniest constituents, thus connecting present knowledge of the physics of subatomic particles at extreme conditions of densities with astrophysical observations.

Experimental gravitational astronomy

The activities of the group focus on the development of high precisions instruments and techniques.

Experimental Research & Development

Regarding instrumentation, the main developments regard the Spanish contribution to the LISA mission, which is led by Dr. Miquel Nofrarias and consists in the Science Diagnostics Subsystem.

There are also technological developments associated with a proof of concept grant to develop a pulsar based Navigation system called DeepSPACEPulse.

Our missions

Einstein Probe

Einstein Telescope

eXTP

LIGO

LISA

NewAthena

SKAO

An illustration of an accreting pulsar, or a type of powerful, rotating neutron star actively feeding off a companion star. Credits: NASA

Examples of synergies among projects

All the projects in this department have a common target: The study of the physics of compact objects and other extreme events in the universe from a multi-messenger perspective. In this sense, there is a strong overlap between the different research lines of the department as well as between the different experiments/observatories in which we participate. One example of the potential of this approach is the celebrated GW170817/GRB170817A event consisting of the merger of a binary neutron star system, which is the first event where multimessenger observations included gravitational waves. The combination of theory and observations with multiple messengers led to revolutionary discoveries.