SMILE
Autor: | M. Mastorakis, Konstantinos Tassis, Ian Browne, K. E. Dolapsaki, A. C. S. Readhead, P. N. Wilkinson, Carolina Casadio, Vincent Pelgrims, V. Diamantopoulos, G. Kalaitzidakis, K. Psarras, Talvikki Hovatta, Vasiliki Pavlidou, K. Gkimisi, H. K. Vedantham, J. A. Zensus, D. Blinov, Evangelia Ntormousi, K. Nikolaou, N. Mandarakas |
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Přispěvatelé: | Astronomy |
Jazyk: | angličtina |
Rok vydání: | 2021 |
Předmět: |
Cosmology and Nongalactic Astrophysics (astro-ph.CO)
European VLBI Network Dark matter FOS: Physical sciences Primordial black hole Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences dark matter law.invention Gravitation General Relativity and Quantum Cosmology law quasars: general 0103 physical sciences Very-long-baseline interferometry Surface brightness 010303 astronomy & astrophysics Physics Spectral index 010308 nuclear & particles physics gravitational lensing: strong Astronomy and Astrophysics Lens (optics) Space and Planetary Science techniques: interferometric Astrophysics - Cosmology and Nongalactic Astrophysics |
Zdroj: | Monthly Notices of the Royal Astronomical Society, 507(1), L6-L10 Monthly Notices of the Royal Astronomical Society, 507, L6-L10. Oxford University Press |
ISSN: | 1365-2966 0035-8711 |
Popis: | Dark Matter (DM) halos with masses below $\sim10^{8}$ $M_{\odot}$, which would help to discriminate between DM models, may be detected through their gravitational effect on distant sources. The same applies to primordial black holes, considered as an alternative scenario to DM particle models. However, there is still no evidence for the existence of such objects. With the aim of finding compact objects in the mass range $\sim$ 10$^{6}$ -- 10$^{9}$$M_{\odot}$, we search for strong gravitational lenses on milli (mas)-arcseconds scales (< 150 mas). For our search, we used the Astrogeo VLBI FITS image database -- the largest publicly available database, containing multi-frequency VLBI data of 13828 individual sources. We used the citizen science approach to visually inspect all sources in all available frequencies in search for images with multiple compact components on mas-scales. At the final stage, sources were excluded based on the surface brightness preservation criterion. We obtained a sample of 40 sources that passed all steps and therefore are judged to be milli-arcsecond lens candidates. These sources are currently followed-up with on-going European VLBI Network (EVN) observations at 5 and 22 GHz. Based on spectral index measurements, we suggest that two of our candidates have a higher probability to be associated with gravitational lenses. 6 pages, 1 figure; accepted for publication |
Databáze: | OpenAIRE |
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