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PhD Fellowship in Binary black hole mergers from globular clusters

Institute of Cosmos Sciences
Fecha inicio solicitud: 
Mar, 01/11/2022
Fecha límite solicitud: 
Mié, 25/01/2023


The doctoral fellowship programme INPhINIT ”la Caixa” is devoted to attracting talented Early-Stage Researchers—of any nationality—who wish to pursue doctoral studies in Spanish or Portuguese territory. Sponsored by ”la Caixa” Foundation, it is aimed at supporting the best scientific talent and fostering innovative and high-quality research in Spain and Portugal by recruiting outstanding international students and offering them an attractive and competitive environment for conducting research of excellence.

The Institute of Cosmos Sciences of the University of Barcelona is a research centre accredited with the Spanish Seal of Excellence María de Maeztu in 2020, the perfect place to carry out your PhD project through an INPhINIT Incoming fellowship.


Research Project:

Gravitational waves (GWs) provide a new window on our Universe. The vast majority of the GW detections by the LIGO-Virgo interferometers are from binary black holes (BBHs). The origin of these BBHs is an open question: they may have a cosmological origin and be part of the dark matter in the Universe. Alternatively, they have an astrophysical origin and formed from binary massive stars, or in dynamical interactions in dense stellar systems such as globular clusters (GCs).

 This project aims to understand the contribution of dynamically formed BBH mergers. Understanding this is of vital importance to understand the nature of BBHs, but it is challenging because the BBH properties and merger rate in this dynamical channel depend sensitively on the unknown initial properties of GCs that formed between now and more than 10 Gyr ago. You will constrain the contribution of the dynamical channel by comparing population models of GC evolution and BBH mergers to observations of Milky Way GCs and use the fact that BHs in GCs affect their observable properties and the stellar escape rate from GCs. You will exploit data from the Gaia space telescope and related surveys such as WEAVE to chart the demographics of BHs in both dissolved and surviving GCs.

 The ICCUB is a full member of the Virgo collaboration and actively involved in Gaia (PI Carme Jordi) and the WEAVE survey, giving you access new data and analysis allowing you to work on the forefront of GW sand Milky Way research. You will join the enthusiastic Virgo and Gaia research groups of the ICCUB who organize weekly science meetings, journal clubs and seminars. You will also benefit from scientific collaborations with various ICCUB staff in the areas of star formation (Paolo Padoan), galaxy formation (Chervin Laporte, Teresa Antoja), cosmology (Licia Verde, Jordi Miralda) and black holes (Cristiano Germani, Jaume Garriga). Finally, you will be part of international collaborations with groups in Europe, Canada and the US.


Job position description

In this PhD project you will model the evolution of globular cluster (GC) populations in different galaxy types, with a particular focus on the Milky Way. You will make predictions for the present-day structure and kinematics of GCs, their distribution in the galaxy, and the distribution of the escaped stars in the galaxy. You will compare these to observations of GCs and field stars that escaped from surviving and dissolved GCs. All of these observables are sensitive to the details of the black hole (BH) populations in the GCs, so astronomical observations can be used to constrain BH dynamics.

 The research group at ICCUB - led by Prof Mark Gieles - developed an ultra-fast code for simulating the evolution of GCs and their BH populations, enabling the exploration of the parameter space of initial properties of GCs. This will be used to model GC populations and chart the demographics BHs in GCs, now and in the past.

These population models are then combined with fast models for the evolution of the BBHs within the GCs to forward model the rate and properties of BBH mergers. The results will provide insights in both the evolutionary history of each GC and its BH population as well as the resulting BBH merger rates, constrained by observational data. The results for the Milky Way GC population are then extrapolated to compute the BBH merger rate of all GCs in the Universe across cosmic time. The predictions include merger rate as a function of redshift, BH masses, mass ratios and the distribution of orbital eccentricities. These will be compared to gravitational wave (GW) data of BBH mergers in the ongoing LIGO-Virgo observing runs, to provide tight constraints on the fraction of all BBH mergers that originate from the dynamical channel. This project also sheds light on the parameters describing the initial conditions of GCs, thereby opening to door to use GWs to constrain star and cluster formation in the early Universe.


More information:

Group leader 

Prof. Mark Gieles 

Research product / Research group 

Pi description

ICCUB participation in Virgo

ICCUB participation in Gaia

paper presenting a model for binary black hole mergers from globular clusters and a comparison to the latest catalogue of gravitational wave sources.

recent paper on the inference of a large black hole population in a Galactic globular cluster from its tidal tails

recent paper demonstrating how the mass of a black hole population can be inferred from observations of the globular cluster 47 Tuc.


Employment conditions 

The maximum total payment amount will be €122,592, as broken down below: 

- An annual payment of €35,800 to the institution to cover the Fellow’s contract, who will receive a gross annual income around €28.000. This amount might vary if there are modifications in the legal framework.

- €3,500 per year, as an additional amount for conferences, courses, research stays, consumables, equipment, charges for the use of intellectual property, etc. 

The ”la Caixa” Foundation will award a prize of €7,500 (subject to taxes), which will be paid to the  fellows who deposit their thesis within 6 months after the third year of their fellowship has ended.

  • The tuition fees to the official doctoral programme 

In addition to financial support, the fellowship includes a training programme on transversal skills, which has been specially designed by leading international institutions in the sector. 

For more information on the employment conditions, please refer to this document.


Working at the Institute of Cosmos Sciences

The Institute of Cosmos Sciences is a research institute of the University of Barcelona. It is an interdisciplinary centre dedicated to fundamental research in the fields of cosmology, astrophysics, and particle physics. In addition, the institute has a strong technology program through its participation in international collaborations in observational astronomy and experimental particle physics.

Moreover, the ICCUB participates in many key international scientific consortia and projects, such as the Large Hadron Collider, the Gaia astrometric space mission, the MAGIC / CTA high-energy astrophysics telescopes, and the Virgo gravitational wave detector, among others. Additional information about the Institute and the University of Barcelona can be found here.

You will be encouraged to contribute and interact with other researchers in the vibrant and international research environment as well as to participate in our outreach initiatives, more information at serviAstro and serviParticules.

As part of the University of Barcelona, the ICCUB is a recipient of the European Commission’s HR Excellence in Research (HRS4R) Award, which recognises, among other achievements, respect for equal opportunities and the capacity to attract talent in a positive working environment that promotes the pursuit of successful research careers. The ICCUB respects the principles of open, transparent, merit-based selection. We strongly encourage women and underrepresented minorities in physical sciences to apply. For additional information please see the Diversity, equity and inclusion Commission.

The ICCUB is located in Barcelona, considered the 8th World's Best Cities 2021: one with near-perfect weather year-round, miles and miles of beaches, iconic parks, striking architecture and colourful neighbourhoods that march to their own beat—artistic, sophisticated, bohemian. Moreover, it is a pole of attraction for the technology sector, a top choice to establish a company in this sector, and it hosts some of the world's major technological events, such as the Mobile World Congress and the Smart City Expo. In addition, Barcelona and its metropolitan area is a leading destination on the map of global technological ecosystems and has infrastructures such as science parks, universities and the 22@ district.



In order to be accepted, candidates must meet the following eligibility requirements:

  • Experience: At the call deadline, applicants must be in the first four years (full-time equivalent research experience) of their research careers and not yet have been awarded a doctoral degree or be in a position to apply for one. 
  • Studies pursued: Applicants must hold a higher education degree that makes them eligible to enroll in a doctoral programme before starting at their host institutions.

The host university will verify, upon starting the admission process to the doctoral programme, that the studies taken up by the selected candidates make them eligible to enroll in an official doctoral programme in accordance with the regulations in force in Spain or Portugal. Should they be found not eligible after verification, the fellowship will be withdrawn. 

Under no circumstances may candidates have previously enrolled in the same doctoral studies for which they are applying for the fellowship.

  • Geographic mobility: Candidates must not have resided or have carried out their main activity (work, studies, etc.) in Spain for more than 12 months in the 3 years immediately prior to the call deadline. Short stays, such as holidays, done in a country other than their country of usual residence (where they carried out their main activity), will be considered as time spent in their country of usual residence.
  • Level of English: Candidates must have a demonstrable level of English (B2 or higher).

For more information on the candidates requirements, please refer to this document.


Application Procedure

All applications must be submitted online through the following link in English. For more information on the application procedure, please refer to this document.

Inquiries about the application submission can be directed to


Deadline: Please submit your applications by January 25th 2023 at 2pm. 


Selection process:

The process is comprised of three phases:

  • Eligibility screening: all applications received are reviewed to check the accomplishment of the eligibility criteria published in the rules for participation
  • Remote evaluation (shortlisting): an evaluation panel will review the applications and those that receive the highest scores will pass to the next stage.
  • Personal interviews: shortlisted candidates are invited to a remotely interview before a multidisciplinary committee on May 23, 35 and 25 2023.

The rating criteria that govern the selection process can be found in the Evaluation of applications section of the ”la Caixa” Fellowship Programme website.

For more information on the selection process, please refer to this document.




Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No713673.

The co-funded part of the programme runs from 01/10/2016 to 30/09/2021 and finances the researchers recruited under Call 2017 and 2018.