1. Simulations of Tidal Disruption Events Observations with the LSSTKatja Bricman, 2017, magistrsko delo Opis: The Large Synoptic Survey Telescope (LSST) will produce a multi-colour survey of 25000 square deg of the Southern sky during its 10 years of operations. It will observe over 20 billion galaxies and a similar number of stars, map the Solar System and the Milky Way, and probe dark matter and dark energy. In addition, it will discover thousands of transients every night, including new classes of objects, which have not yet been observed. Due to its large coverage of the sky it will be a perfect tool for the search of rare Tidal Disruption Events (TDEs), which occur when a star passes close by a supermassive black hole and gets disrupted by its tidal force. Afterwards the stellar debris fall back to the black hole, initially at a rate exceeding
the Eddington rate, producing an outflow, which releases a flare of energy. When the fallback rate subsides below the Eddington rate, the gas accretes onto the black hole via accretion disk. The LSST simulation framework enables us to simulate observations of different types of objects with the LSST. In this work, we include TDEs in the LSST simulation framework, estimate the number of detected TDEs, and simulate their light curves using a theoretical model, which predicts a t^(-2.6) light curve decline with time in the outflow phase and a t^{-0.4} decline in the disk phase. We also take a closer look at the distribution of the detected TDEs over cosmological redshift and black hole mass. Najdeno v: osebi Ključne besede: Astronomical observations, Large Synoptic Survey Telescope, Tidal Disruption Events, Black Holes, simulations Objavljeno: 17.10.2017; Ogledov: 3632; Prenosov: 0
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4. Opazovanja plimskih raztrganj zvezd z Velikim sinoptičnim pregledovalnim teleskopomKatja Bricman, A. Gomboc, 2018, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Plimska raztrganja zvezd so redki dogodki, do katerih pride, ko zvezdo zanese v bližino masivne črne luknje v središču galaksije, kjer jo močne plimske sile črne luknje raztrgajo. Blišč svetlobe, ki ob tem nastane, lahko opazujemo do kozmoloških razdalj. Veliki sinoptični pregledovalni teleskop (Large Synoptic Survey Telescope - LSST), ki je v gradnji v Čilu, bo ponavljajoče opazoval 18.000 kvadratnih stopinj južnega neba v šestih optičnih filtrih do limitne magnitude 24,5 v r filtru. Omogočal bo opazovanja 20 milijard zvezd in 20 milijard galaksij, s primerjavo starih in novih posnetkov pa bo zaznal spremembe na nebu oziroma tranzientne izvore ter bo tako odlično orodje za iskanje plimskih raztrganj zvezd. Z uporabo simulacijskega orodja LSST smo simulirali opazovanja plimskih raztrganj zvezd na majhnem delu neba velikosti 20,25 kvadratnih stopinj. S pomočjo simuliranih svetlobnih krivulj smo ocenili število plimskih raztrganj zvezd, ki jih bo teleskop odkril v desetih letih delovanja. Najdeno v: osebi Ključne besede: Plimska raztrganja zvezd, pregledovalni teleskopi Objavljeno: 10.05.2021; Ogledov: 1288; Prenosov: 0 |
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6. Studying TDEs in the era of LSSTKatja Bricman, A. Gomboc, 2019, objavljeni povzetek znanstvenega prispevka na konferenci Opis: The observing strategy with continuous scanning and large sky coverage of the upcoming ground-based Large Synoptic Survey Telescope (LSST) will make it a perfect tool in search of rare transients, such as Tidal Disruption Events (TDEs). Bright optical flares resulting from tidal disruption of stars by their host supermassive black hole (SMBH) can provide us with important information about the mass of the SMBH involved in the disruption and thus enable the study of quiescent SMBHs, which represent a large majority of SMBHs found in centres of galaxies. These types of transients are extremely rare, with only about few tens of candidates discovered so far. It is expected that the LSST will provide a large sample of new TDE light curves. Here we present simulations of TDE observations using an end-to-end LSST simulation framework. Based on the analysis of simulated light curves we estimate the number of TDEs with good quality light curves the LSST is expected to discover in 10 years of observations. In addition, we investigate whether TDEs observed by the LSST could be used to probe the SMBH mass distribution in the universe. Najdeno v: osebi Ključne besede: Tidal Disruption Events, sky surveys Objavljeno: 04.01.2021; Ogledov: 1729; Prenosov: 70 |
7. Observing TDEs in the era of LSSTKatja Bricman, 2019, objavljeni povzetek znanstvenega prispevka na konferenci Opis: The upcoming Large Synoptic Survey Telescope (LSST) will observe ~18000 square degrees of the Southern sky and is expected to discover thousands of transients every night due to its large coverage of the sky and its observing strategy. Being an exceptional transient hunter, we expect the LSST to increase the current observed sample of Tidal Disruption Events (TDEs) by a factor of ~1000 in 10 years of survey duration. TDEs are one of the only probes of dormant supermassive black holes in the Universe, and if their observed optical light curves are sampled frequently enough, TDEs can serve as indicators of SMBH mass. In this talk I will present our simulations of TDE observations with LSST, the resulting SMBH mass distributions of observed TDEs, and the efficiency of different proposed observing strategies of LSST in finding these rare transients. Najdeno v: osebi Ključne besede: Tidal Disruption Events, sky surveys Objavljeno: 04.01.2021; Ogledov: 1649; Prenosov: 61
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8. Observing TDEs in the era of LSSTKatja Bricman, 2020, objavljeni povzetek znanstvenega prispevka na konferenci Opis: The upcoming Large Synoptic Survey Telescope (LSST) will observe ~18000 square degrees of the Southern sky and is expected to discover thousands of transients every night due to its large coverage of the sky and its observing strategy. Being an exceptional transient hunter, we expect the LSST to increase the current observed sample of Tidal Disruption Events (TDEs) by a factor of ~1000 in 10 years of survey duration. TDEs are one of the most promising phenomena in the study of dormant supermassive black holes (SMBHs) in the Universe, and if their observed optical light curves are sampled frequently enough, TDEs can serve as indicators of SMBH mass. We present our simulations of TDE observations with the LSST, the resulting SMBH mass distributions of observed TDEs, and the efficiency of different proposed observing strategies of the LSST in finding these rare transients. Najdeno v: osebi Ključne besede: Tidal Disruption Events, Supermassive black holes, sky surveys Objavljeno: 04.01.2021; Ogledov: 1589; Prenosov: 0
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10. Black holes, gravitational waves and fundamental physics: a roadmapKatja Bricman, Andreja Gomboc, Tanja Petrushevska, Leor Barack, Aurora Clerici, Christopher Eckner, Nada Ihanec, Gabrijela Zaharijas, 2019, pregledni znanstveni članek Opis: The grand challenges of contemporary fundamental physics—dark matter, dark energy, vacuum energy, inflation and early universe cosmology, singularities and the hierarchy problem—all involve gravity as a key component. And of all gravitational phenomena, black holes stand out in their elegant simplicity, while harbouring some of the most remarkable predictions of General Relativity: event horizons, singularities and ergoregions.
The hitherto invisible landscape of the gravitational Universe is being unveiled before our eyes: the historical direct detection of gravitational waves by the LIGO-Virgo collaboration marks the dawn of a new era of scientific exploration. Gravitational-wave astronomy will allow us to test models of black hole formation, growth and evolution, as well as models of gravitational-wave generation and propagation. It will provide evidence for event horizons and ergoregions, test the theory of General Relativity itself, and may reveal the existence of new fundamental fields. The synthesis of these results has the potential to radically reshape our understanding of the cosmos and of the laws of Nature.
The purpose of this work is to present a concise, yet comprehensive overview of the state of the art in the relevant fields of research, summarize important open problems, and lay out a roadmap for future progress. This write-up is an initiative taken within the framework of the European Action on 'Black holes, Gravitational waves and Fundamental Physics. Najdeno v: osebi Ključne besede: black holes, gwverse Objavljeno: 24.06.2019; Ogledov: 2779; Prenosov: 0
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