| 1. |
- Andreoni, Igor, et al.
(författare)
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Target-of-opportunity Observations of Gravitational-wave Events with Vera C. Rubin Observatory
- 2022
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Ingår i: Astrophysical Journal Supplement Series. - : American Astronomical Society. - 0067-0049 .- 1538-4365. ; 260:1
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Tidskriftsartikel (refereegranskat)abstract
- The discovery of the electromagnetic counterpart to the binary neutron star (NS) merger GW170817 has opened the era of gravitational-wave multimessenger astronomy. Rapid identification of the optical/infrared kilonova enabled a precise localization of the source, which paved the way to deep multiwavelength follow-up and its myriad of related science results. Fully exploiting this new territory of exploration requires the acquisition of electromagnetic data from samples of NS mergers and other gravitational-wave sources. After GW170817, the frontier is now to map the diversity of kilonova properties and provide more stringent constraints on the Hubble constant, and enable new tests of fundamental physics. The Vera C. Rubin Observatory's Legacy Survey of Space and Time can play a key role in this field in the 2020s, when an improved network of gravitational-wave detectors is expected to reach a sensitivity that will enable the discovery of a high rate of merger events involving NSs (∼tens per year) out to distances of several hundred megaparsecs. We design comprehensive target-of-opportunity observing strategies for follow-up of gravitational-wave triggers that will make the Rubin Observatory the premier instrument for discovery and early characterization of NS and other compact-object mergers, and yet unknown classes of gravitational-wave events.
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| 2. |
- Barack, Leor, et al.
(författare)
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Black holes, gravitational waves and fundamental physics : a roadmap
- 2019
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Ingår i: Classical and quantum gravity. - : IOP Publishing. - 0264-9381 .- 1361-6382. ; 36:14
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Forskningsöversikt (refereegranskat)abstract
- 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'.
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| 3. |
- Salafia, Om Sharan, et al.
(författare)
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Multiwavelength View of the Close-by GRB 190829A Sheds Light on Gamma-Ray Burst Physics
- 2022
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 931:2
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Tidskriftsartikel (refereegranskat)abstract
- We monitored the position of the close-by (about 370 Mpc) gamma-ray burst GRB 190829A, which originated from a massive star collapse, through very long baseline interferometry (VLBI) observations with the European VLBI Network and the Very Long Baseline Array, carrying out a total of nine observations between 9 and 117 days after the gamma-ray burst at 5 and 15 GHz, with a typical resolution of a few milliarcseconds. From a state-of-the art analysis of these data, we obtained valuable limits on the source size and expansion rate. The limits are in agreement with the size evolution entailed by a detailed modeling of the multiwavelength light curves with a forward-plus-reverse shock model, which agrees with the observations across almost 18 orders of magnitude in frequency (including the HESS data at TeV photon energies) and more than 4 orders of magnitude in time. Thanks to the multiwavelength, high-cadence coverage of the afterglow, inherent degeneracies in the afterglow model are broken to a large extent, allowing us to capture some unique physical insights; we find a low prompt emission efficiency of less than or similar to 10(-3), a low fraction of relativistic electrons in the forward shock downstream chi ( e ) < 13% (90% credible level), and a rapid decay of the magnetic field in the reverse shock downstream after the shock crossing. While our model assumes an on-axis jet, our VLBI astrometry is not sufficiently tight as to exclude any off-axis viewing angle, but we can exclude the line of sight to have been more than similar to 2 degrees away from the border of the gamma-ray-producing region based on compactness arguments.
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