Cosmic Rulers: Masers as Tools for Probing Structure in the Galaxy and Beyond, from AU to kpc

arXiv:2606.31237 · astro-ph.GA, astro-ph.SR · Submitted 2026-06-30 · Read on arXiv

Kazi L. J. Rygl, Anna Bartkiewicz, Olga Bayandina, Andreas Brunthaler, Sandra Etoka, Simon Ellingsen, Dieter Engels, Tomoya Hirota, Arshia Maria Jacob, Jacco Th. van Loon, Alberto Sanna, Lucero Uscanga

astro-ph.GA, astro-ph.SR

Submitted: 2026-06-30

Comments: Published in Advancing Astrophysics with the SKA II (AASKAII), 2026 (arXiv:2606.20366). Report-no:AASKAII/Rygl01. Advancing Astrophysics with the SKA II (AASKAII) outlines the transformative scientific advances that will be enabled by the SKA telescopes

Project page: http://vlbi.sci.ibaraki.ac.jp/iMet

License: http://creativecommons.org/licenses/by-nc-sa/4.0/

The gist: Maser emission provides an unique window into astronomical sources across vast spatial scales - from tens to hundreds of astronomical units around protostars and evolved stars up to kiloparsecs in

Terminology

Trace — 15× in this paper · explained in 2 episodes
Accuracy — 5× in this paper · explained in 1 episode
Verification — 4× in this paper · explained in 2 episodes
Core — 3× in this paper · explained in 2 episodes
Metallicity — 3× in this paper · explained in 3 episodes
AGN — 2× in this paper · explained in 1 episode
Abundance — 2× in this paper · explained in 1 episode
Calibration — 2× in this paper · explained in 7 episodes
European VLBI Network — 2× in this paper
Active Galactic Nuclei — 1× in this paper
Aperture — 1× in this paper · explained in 1 episode
Fidelity — 1× in this paper · explained in 2 episodes
Large Magellanic Cloud — 1× in this paper
Parkes and Australian Telescope Compact Aarray — 1× in this paper
Small Magellanic Cloud — 1× in this paper
Very Large Array — 1× in this paper

Abstract

Maser emission provides an unique window into astronomical sources across vast spatial scales - from tens to hundreds of astronomical units around protostars and evolved stars up to kiloparsecs in distant galaxies. These natural microwave amplifiers penetrate dust shells in star-forming regions, revealing the dynamics of accretion disks and outflows, trace envelopes and winds of evolved stars, map Galactic structure, while also allowing us to follow the evolution of all these systems. Owing to their compactness and brightness masers provide precise astrometry as cosmic rulers: measuring positions, structures and kinematics in dense regions, not easily accessible at other wavelengths. SKA-Mid will observe hydroxyl, methanol, and formaldehyde masers using bands 2, 5a and 5b, and later methylidyne radical masers in band 4. SKA-Mid's sensitivity and broad frequency coverage will support discoveries of new maser types and allow for simultaneous multi-transition and multi-species maser observations. In addition, bright masers can serve in the science verification of the SKA-Mid array during the deployment phase.

Sources

Discovery of the first extra-galactic SiO maser

Terminology

Abstract

Sources

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