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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.sup.1-4; 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. The sharp boundaries of these bubbles trace collisionless and non-radiative shocks, and corroborate the idea that the bubbles are not a remnant of a local supernova.sup.5 but part of a vast Galaxy-scale structure closely related to features seen in [gamma]-rays.sup.6. Large energy injections from the Galactic centre.sup.7 are the most likely cause of both the [gamma]-ray and X-ray bubbles. The latter have an estimated energy of around 10.sup.56 erg, which is sufficient to perturb the structure, energy content and chemical enrichment of the circumgalactic medium of the Milky Way. Observations from the eROSITA telescope reveal soft-X-ray-emitting bubbles extending above and below the Galactic plane, which arose from energy injected into the Galactic halo from past activity in the Galactic centre., Author(s): P. Predehl [sup.1] , R. A. Sunyaev [sup.2] [sup.3] , W. Becker [sup.1] [sup.4] , H. Brunner [sup.1] , R. Burenin [sup.2] , A. Bykov [sup.5] , A. Cherepashchuk [...]

Highlights from News & Views published this year. Highlights from News & Views published this year., Author Affiliations: Viruses, microscopy and fast radio bursts: 10 remarkable discoveries from 2020 Credit: Kamioka Observatory/Institute for Cosmic Ray Research/The University of Tokyo Inside of the Super-Kamiokande detector. Matter-antimatter symmetry [...]

Since the autumn of 1609, when Galileo Galilei first looked at the Milky Way through a telescope, we've known that we live in a flattened distribution of stars, but not [...]

The first stars are predicted to have formed within 200 million years after the Big Bang (1), initiating the cosmic dawn. A true first star has not yet been discovered, [...]

The nature of our Milky Way galaxy is re-examined from an eclectic point of view. Evidence for a central bar, for example, is not reflected in the distribution of RR Lyrae variables in the central bulge (Majaess. Acta Astron. 60,55 (2010); Dekany et al. arXiv:1309.5933. 2013), and it is not clear if either a 2-armed or 4-armed spiral pattern is appropriate for the spiral arms. Radial velocity mapping of the Galaxy using radio HI, HII, or CO observations is compromised by the assumptions adopted for simple Galactic rotation. The Sun's local standard of rest (LSR) velocity is ~14 km [s.sup.-1] rather than 20 km [s.sup.-1], the local circular velocity is 251 ± 9 km [s.sup.-1] rather than 220 km [s.sup.-1], and young groups of stars exhibit a 10-20 km [s.sup.-1] 'kick' relative to what is expected from Galactic rotation. By implication, the same may be true for star-forming gas clouds affected by the Galaxy's spiral density wave, raising concerns about their use for mapping spiral arms. Proper motion data in conjunction with the newly-estimated velocity components for the Sun's motion imply a distance to the Galactic centre of [R.sub.0] = 8.34 ± 0.27 kpc, consistent with recent estimates, which average 8.24 [+ or -] 0.09 kpc. A cosinusoidal Galactic potential is not ruled out by observations of open star clusters. The planetary nebula cluster Bica 6, for example, has a near-escape orbit for a Newtonian potential, but a near-normal orbit in a cosinusoidal potential field. The nearby cluster Collinder 464 also displays unusually large tidal effects consistent with those expected for a cosinusoidal potential. A standard Newtonian version of the Virial theorem for star clusters yields very reasonable masses (~3 x [10.sup.11] [M.sub.[dot in a circle]] and ~4 x [10.sub.11] [M.sub.[dot in a circle]]) for the Milky Way and M31 subgroups of the Local Group, respectively. A cosinusoidal relation should yield identical results. PACS Nos.: 04.50.Kd, 95.85.Bh, 96.60.-j, 97.10.-q, 98.35.-a, 98.56.-p. Nous reetudions la nature de la Voie Lactee a partir d'un point de vue eclectique. L'evidence pour une barre centrale ne se reflete pas dans la distribution des variables de type RR Lyrae dans le bulbe galactique central (Majaess. Acta Astron. 60, 55 (2010); Dekany et al. arXiv:1309.5933. 2013) et ce n'est pas clair si on doit favoriser un patron spiral a deux bras ou a quatre bras. La cartographie de la vitesse radiale de la galaxie par l'observation des signaux radio H I, H II ou CO est compromise par l'hypothese adoptee pour la rotation simple de la galaxie. La vitesse du referentiel local standard du Soleil est de ~14 km [s.sup.-1] plutot que de 20 km [s.sup.-1], la vitesse locale circulaire est de 251 ± 9 km [s.sup.-1] au lieu de 220 km [s.sup.-1] et la vitesse des jeunes groupes d'etoiles est plus vite de 10-20 km [s.sup.-1] que ce qu'on attend de la rotation de la galaxie. Il s'ensuit qu'il pourrait en etre de meme pour les nuages dans lesquels se forment des etoiles et qui sont soumis a l'onde de densite spirale de la galaxie, ce qui mene a des questions lors de leur utilisation pour cartographier les bras spiraux. Ces donnees corrigees sur les mouvements, avec les nouveaux estimes des composantes de vitesse du Soleil, impliquent une distance du centre de la galaxie de 8.34 ± 0.27 kpc, coherente avec des estimes recents dont la moyenne se situe a 8.24 ± 0.09 kpc. Les observations sur les amas ouverts ne contredisent pas un potentiel en cosinus pour la galaxie. L'amas de nebuleuses planetaires Bica 6, par exemple, a pratiquement une orbite de liberation pour un potentiel de Newton, mais une orbite normale pour un potentiel en cosinus. L'amas rapproche Collinder 464 montre des effets de maree tres forts, egalement coherents avec un potentiel en cosinus. Une version newtonienne standard du theoreme du viriel pour les amas d'etoiles donne les valeurs tres raisonnables, respectivement ~3 x [10.sup.11] [M.sub.[dot in a circle]] et ~4 x [10.sup.11] [M.sub.[dot in a circle]], pour les sous-groupes Voie Lactee et M31 du Groupe Local. Une relation du type cosinus devrait donner des resultats identiques. [Traduit par la Redaction], 1. Introduction Introductory astronomy textbooks usually contain artist impressions of what our Galaxy looks like as viewed by an observer located well above its central plane (e.g., Wikipedia entry for [...]

'The center of our galaxy is complex, extreme, and violent,' says Daniel Wang of the University of Massachusetts, Amherst. To make sense of it, Wang combined radio imagery (purple-gray) from [...]