The discovery of gravitational waves 9 years ago triggered an explosive development of gravitational wave astronomy. Almost 100 detections of wave sources have already been published. Currently, the O4 observational campaign is underway, which will bring hundreds more detections. Gravitational wave astronomy allows a new perspective on the Universe, exploring previously inaccessible regions of space and experimentally testing General Relativity. The doctoral project involves research within the broad field of gravitational wave astronomy, both in theory and observation.

We are looking for a candidate to work with a team of scientists involved in the broad field of gravitational wave astrophysics. Good preparation in astronomy, data analysis, and knowledge of General Relativity will be an asset. The project will involve analyzing astrophysical sources of gravitational waves such as binary systems, supernovae, or sources of continuous signals like rotating asymmetric neutron stars. Additionally, the doctoral project will require participation in activities for Virgo, including observational duties and data analysis.
The project will be carried out under the supervision of Prof. Tomasz Bulik, Prof. Dorota Rosińska, in collaboration with Dr. Marek Szczepańczyk from the Faculty of Physics, UW. The doctoral student may receive an additional grant from Prof. Bulik’s NCN grant.

A significant portion of stars near the Sun are in binary, or even multiple systems. We know this because these objects can be studied using various methods. Also, in other regions of the Galaxy, stars are in binary systems, but we do not know if the fraction of stars in binary systems and the parameters of this population, such as mass ratios and orbit sizes, are the same as near the Sun. For binary systems in the central bulge of the Galaxy, the best method for statistical studies is gravitational microlensing.

The PhD student will search for or conduct detailed studies of microlensing events caused by binary star systems. In the long run, such research will allow the study of the initial mass function for stars in the central bulge of the Galaxy.

The research will be carried out within the supervisor’s SONATA BIS grant.

The doctoral studies propose conducting research in the dynamically developing field of Gravitational Wave Astronomy, which was born in 2015 with the first detection of gravitational waves from the coalescence of two massive stellar black holes GW150914. This groundbreaking discovery was awarded the Nobel Prize in Physics two years later. Binary systems of neutron stars and black holes, rotating neutron stars, and supernova explosions are the strongest sources of gravitational waves for the LIGO-VIRGO-KAGRA detectors and the third-generation Einstein Telescope.

During the PhD, the student will study the properties of these sources using relativistic numerical codes. Specifically, it is proposed to model differentially rotating hot neutron stars, which are one of the remnants of the coalescence of neutron stars in binary systems or during the collapse of a massive star’s core during a supernova explosion.

There is also an opportunity to participate in the search for gravitational waves from various astrophysical sources by analyzing data from the VIRGO/LIGO detectors as part of the Virgo-POLGRAW research group. Projects are conducted in collaboration with research centers in France, Italy, Greece, Spain, and the USA.

A large proportion of pulsating red giants exhibit additional long-period variability known as LSP (Long Secondary Period). It is suspected that the cause of this variability is that the star is in a binary system, where the companion is a former planet that has accumulated some of the material lost by the giant.

The aim of the research will be to analyze photometric and spectroscopic observations of LSP stars, and to conduct hydrodynamic modeling of binary systems to verify this hypothesis. The research will be conducted within the ERC grant “A MISTery of Long Secondary Periods in Pulsating Red Giants – Traces of Exoplanets?” (LSP-MIST).

The candidate is required to have programming skills.

The Gaia space mission has been operating continuously since 2014, collecting time series data with photometric, astrometric, and spectroscopic data for over a billion stars in our Galaxy. Among the observed objects are stars and quasars lensed by stellar-mass and intermediate-mass black holes, some of which may be of primordial origin and may partially solve the mystery of dark matter. Detection of black holes will be possible thanks to the enormous precision of data collected by the Gaia mission, especially astrometric time series.

As part of their research, the PhD student will analyze unique data from the Gaia mission as well as collect additional observations from ground-based telescopes to complement Gaia’s data. The PhD student will be officially included in the European Gaia consortium, within which they will be able to work on data accessible only to consortium members. Participation in international conferences, visits to astronomical observatories around the world, and visits to collaborating centers are planned.