Publications by authors named "R Sunyaev"

Article Synopsis
  • The Milky Way's center contains a dormant black hole, Sagittarius A (Sgr A), with a mass of about 4 million solar masses and low luminosity compared to active galactic nuclei.
  • Researchers have studied X-ray reflections from surrounding dense gas to investigate Sgr A's past activity, suggesting it flared up significantly in the past.
  • Observations from the Imaging X-ray Polarimetry Explorer revealed a 31% polarization degree in X-rays, indicating Sgr A was much more active around 200 years ago, with luminosity similar to that of a Seyfert galaxy.
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The origins of the high-energy cosmic neutrino flux remain largely unknown. Recently, one high-energy neutrino was associated with a tidal disruption event (TDE). Here we present AT2019fdr, an exceptionally luminous TDE candidate, coincident with another high-energy neutrino.

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The halo of the Milky Way provides a laboratory to study the properties of the shocked hot gas that is predicted by models of galaxy formation. There is observational evidence of energy injection into the halo from past activity in the nucleus of the Milky Way; however, the origin of this energy (star formation or supermassive-black-hole activity) is uncertain, and the causal connection between nuclear structures and large-scale features has not been established unequivocally. Here we report soft-X-ray-emitting bubbles that extend approximately 14 kiloparsecs above and below the Galactic centre and include a structure in the southern sky analogous to the North Polar Spur.

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We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400  deg^{2} patch of sky centered on RA 0 h, Dec. -57.

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The hot (10(7) to 10(8) kelvin), X-ray-emitting intracluster medium (ICM) is the dominant baryonic constituent of clusters of galaxies. In the cores of many clusters, radiative energy losses from the ICM occur on timescales much shorter than the age of the system. Unchecked, this cooling would lead to massive accumulations of cold gas and vigorous star formation, in contradiction to observations.

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