IAC3 member David Keitel has been elected as co-chair of the continuous-waves working group of the LIGO Scientific Collaboration (LSC), one of the collaboration’s four main observational working groups. Using data from the LIGO, Virgo, KAGRA and GEO600 detectors, this international research team pursues what could be the next big discovery in gravitational-wave astrophysics: the first detection of long-duration, exceedingly weak signals from rapidly spinning neutron stars. Much fainter than the now-famous chirps from colliding black holes, such “continuous waves” have never been detected before. But we expect them to be emitted by neutron stars, ultra-compact objects heavier than our sun, as long as they are somewhat deformed: think of them carrying a mountain, or really just a very small bump of a few centimeters. As the neutron star rotates at speeds of many times a second, at every turn that deformation swirls around the surrounding space-time, sending out gravitational waves. Eventually, here on Earth, these cause a tiny but persistent shaking of the immensely precise laser interferometer detectors like LIGO. The core challenge that the group has been working on for decades is to develop computational algorithms of the highest precision to tease out these patterns of continuous-wave signals from the random noise background. With a huge boost to detector sensitivity when the next observing run (“O4”) starts in 2023 (see https://observing.docs.ligo.org/plan/ ), the first detection of such signals may become a reality. It could yield unprecedented insights into the nature of neutron stars, especially into the behaviour of the nuclear matter at extreme densities that they are made from. Searches for more exotic continuous-wave signals could also allow us to study the enigmatic dark matter in the cosmos.
Dr. Keitel is a Beatriz Galindo distinguished researcher in the GRAVITY group at UIB, financed by the Spanish Ministry of Science and Innovation and cofinanced by UIB. He joins Prof. John T. Whelan of RIT (New York) as LSC co-chair of the combined LIGO-Virgo-KAGRA continuous-waves working group, leading the international group together with Prof. Michal Bejger from the Virgo Collaboration and Prof. Yousuke Itoh from the KAGRA Collaboration. See https://cw.docs.ligo.org/public/ for more information on the group. Dr. Keitel has been an active member of the LSC since 2011 working on gravitational-wave data analysis for both continuous waves and compact binary coalescences, and is also a member of the LSC council and an elected member of its program committee. His contributions to the continuous-waves working group include work on all-sky searches for unknown neutron stars on the distributed computing platform Einstein@Home, leadership of the development of a new class of searches for continuous-wave-like but transient signals from binary neutron star merger remnants or glitching pulsars, and serving as maintainer for the group’s open-source software. His term running the continuous-waves working group will last until 2025. He follows in the steps of Prof. Alicia Sintes of IAC3, who co-led the same group from 2016-2018 during the analysis of data from the first two observing runs of the advanced detector generation. Hence this new appointment continues UIB’s international track record of leadership in this field at the cutting edge of astrophysics.