The gas streamer G1–2–3 in the Galactic center

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Authors: S. Gillessen, F. Eisenhauer, Jorge Cuadra, R. Genzel, Diego Calderón, Simran Joharle, Tsvi Piran, D. C. Ribeiro, Christopher M. P. Russell, M. S. Bordoni, A. Burkert, G. Bourdarot
+52 more Antonia Drescher, F. Mang, Thomas Ott, Guido Agapito, Alex Agudo Berbel, Andrea Baruffolo, Marco Bonaglia, Martin R. Black, R. Briguglio, Y. Cao, Luca Carbonaro, G. Cresci, Y. Dallilar, R. Davies, Matthias Deysenroth, Ivan Di Antonio, Amico Di Cianno, Gianluca Di Rico, David S. Doelman, Mauro Dolci, S. Esposito, D. Fantinel, Debora Ferruzzi, H. Feuchtgruber, N. M. Förster Schreiber, Adrian Michael Glauser, Paolo Grani, M. Hartl, David W. Henry, H. Huber, Christoph U. Keller, M. Kenworthy, Kateryna Kravchenko, John F. Lightfoot, David Lunney, Dieter Lutz, M. Macintosh, Filippo Mannucci, DAVID P. J. PEARSON, Alfio Timothy Puglisi, S. Rabien, Christian Rau, A. Riccardi, Bernardo Salasnich, T. Shimizu, Frans Snik, E. Sturm, L. J. Tacconi, W. Taylor, Antony Valentini, C. Waring, Marco Xompero
Cited by: 1
References: 80

Abstract

The black hole in the Galactic center, Sgr A*, is prototypical of ultra-low-fed galactic nuclei. The discovery of a handful of gas clumps with masses on the order of a few Earth masses in its immediate vicinity provides a gas reservoir sufficient to power Sgr A*. In particular, the gas cloud G2 is of interest due to its extreme orbit, on which it passed at a pericenter distance of around 100 AU and notably lost kinetic energy during the fly-by due to interaction with the black hole accretion flow. Thirteen years prior to G2, a similar gas cloud called G1, passed Sgr A* on a similar orbit. The origin of G2 remained a topic of discussion, with models including a central (stellar) source still proposed as alternatives to pure gas clouds. Here, we report the orbit of a third gas clump moving along (nearly) the same orbital trace. Since the probability of finding three stars on such similar orbits is very low, this strongly argues against stellar-based source models. Instead, we show that the gas streamer G1–2–3 plausibly originates from the stellar wind of the massive binary star IRS 16SW. This claim is substantiated by the fact that the small differences between the three orbits – the orientations of the orbital ellipses in their common plane as a function of time – are consistent with the orbital motion of IRS 16SW.

Fields of Study & Subjects

Atmospheric Ozone and Climate Astrophysics and Cosmic Phenomena Spectroscopy and Laser Applications

Publication details

Journal / source
Astronomy and Astrophysics
Publisher
EDP Sciences
Volume
707
Pages
A79–A79
Publication date
2 February 2026
Language
EN