Seminarium Zakładu Astrofizyki

We present the galaxy group catalog for the newly completed 2MASS Redshift Survey up to a magnitude limit of K < 11.75. Consisting of ~ 45 000 redshifts, including 1 041 previously unpublished
redshifts mostly distributed along the Zone of Avoidance. The galaxy group catalog is generated by using a novel, graph theory based, modified version of the friends-of-friends algorithm. The results and

Recent advent of millimetre arrays such as ALMA and NOEMA helps unveiling the long redshift tail (2<z<7) of dusty galaxies, transforming our view of massive star-formation in the very distant Universe. Despite such progress, the dust-to-stellar mass ratio, one of the most important quantities, remains poorly constrained, which prevents us from knowing the complexity of physical processes involved in the production of dust, metals and stars in galaxy evolution.

Neutron stars are very complicated to study due to the extreme conditions occurring there. Mean densities are comparable to the atomic density. The magnetic fields strength on the surface ranges from 104 up to 1011 Tesla. Gravity is strong enough that it acts as a gravitational lens and bends the radiation emitted by the neutron star that the areas normally invisible become visible. The interaction between matter and radiation is very complicated. We must consider scattering processes, absorption, emission and illumination.

Currently ongoing observing run O3 (1st April 2019 - 30th April 2020) of three interferometric detectors (LIGO Livingston and Hanford, Virgo) surveys the largest volume of the Universe till date, and has already delivered more than 40 significant signal candidates. Here I will discuss the current status of the detectors, talk about the interesting signal cases (in particular the recently published GW190425), as well as plans for the future.