Gergely Dálya

Postdoctoral fellow

PhD (Eötvös Loránd University, Budapest, 2022)

Biography:

I am a CNES Research Fellow at the Laboratoire des 2 Infinis, Toulouse working on gravitational-wave astrophysics and multi-messenger astronomy. I lead the Galaxy Catalogues & Electromagnetic Synergies subgroup of the LIGO-Virgo-KAGRA Collaboration and work as the external data representative of the Science Expert Group of the Laser Interferometer Space Antenna (LISA).

I earned my PhD in astrophysics from Eötvös University in April 2022. I created the largest and most complete public all-sky galaxy catalog, GLADE (and its newer versions, GLADE+ and UpGLADE) and applied it in the identification of source galaxies of electromagnetic and gravitational wave transients. The GLADE catalogues have been used by several independent discoverers of the electromagnetic counterpart of the first observed binary neutron star merger, GW170817, and are in use currently for similar purposes by multiple groups worldwide. Besides continuously improving the galaxy catalogs, as a member of the LIGO Cosmology group I work on using the catalog to help calculate the Hubble constant independently of cosmological models. I also worked on testing how model-independent pipelines can reconstruct the gravitational waveforms of eccentric compact binary mergers, as well as on how machine learning tools can help us detect gravitational waves from supernovae. After getting my PhD I worked as a postdoctoral researcher at Ghent University, Belgium, then won the fellowship of the French Space Agency, CNES, to work on cosmological forecasts and data optimization for the future ESA-NASA joint mission, LISA.

Besides scientific research, I am also active in education and public outreach. I have prepared the Hungarian team for the most prestigious astronomical competition for high-school students, the International Olympiad on Astronomy & Astrophysics (IOAA) since 2013, serving as a team leader in several Olympiads. I wrote a comprehensive astronomy textbook for the students, that has since also been in use by the Saudi Arabian and the Romanian teams, as well as used for several university courses.

Links to associated scientific database profiles:

• Publications in MTMT
• Publications in ORCID
• Publications in ResearcherID
• Publications in Google Scholar
• User profile at doktori.hu

Selected publications of recent years:

1. G. Dálya, G. Galgóczi, L. Dobos, et al.: GLADE: A galaxy catalogue for multimessenger searches in the advanced gravitational-wave detector era, MNRAS, 2018, 479, 2, pp. 2374-2381
2. LIGO Scientific Collaboration, Virgo Collaboration, ..., G. Dálya, ... et al.: A gravitational-wave standard siren measurement of the Hubble constant, Nature, 2017, 551, 7678, pp. 85-88
3. Fishbach, M., Gray, R., ... G. Dálya, ... et al.: A standard siren measurement of the Hubble constant from GW170817 without the electromagnetic counterpart, ApJL, 2019, 871, L13
4. Á. Szölgyén, G. Dálya, L. Gondán, P. Raffai: Target-based optimization of advanced gravitational-wave detector network operations, CQG, 2017, 34, 7, id. 075011
5. Derekas, A., Murphy, S. J., G. Dálya, et al.: Spectroscopic confirmation of the binary nature of the hybrid pulsator KIC 5709664 found with the frequency modulation method, MNRAS, 2019, 486, p. 2129