Keck: Young Galaxy's Halo Offers Clues to Its Growth & Evolution

[bystander]

Young Galaxy's Halo Offers Clues to Its Growth and Evolution
W.M. Keck Observatory | 2018 Jul 24

An artist’s concept showing the gaseous halo surrounding a galaxy, illuminated by a narrow band of ultraviolet light called Lyman alpha emission. BX418’s gas halo is about ten times the size of the galaxy itself. Credit: T. Klein, UWM

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A team of astronomers has discovered a new way to unlock the mysteries of how the first galaxies formed and evolved.

In a study lead author Dawn Erb and her team – for the very first time – used new capabilities at W. M. Keck Observatory on Maunakea, Hawaii to examine Q2343-BX418, a small, young galaxy located about 10 billion light years away from Earth.

This distant galaxy is an analog for younger galaxies that are too faint to study in detail, making it an ideal candidate for learning more about what galaxies looked like shortly after the birth of the universe.

BX418 is also attracting astronomers’ attention because its gas halo is giving off a special type of light. ...

Erb’s team used one of the observatory’s newest instruments, the Keck Cosmic Web Imager (KCWI), to perform a detailed spectral analysis of BX418’s gas halo; its properties could offer clues about the stars forming within the galaxy. ...

The Kinematics of Extended Lyα Emission in a Low-mass, Low-metallicity Galaxy at z = 2.3 - Dawn K. Erb, Charles C. Steidel, Yuguang Chen

• Astrophysical Journal Letters 862(1):L10 (2018 Jul 20) DOI: 10.3847/2041-8213/aacff6
  arXiv.org > astro-ph > arXiv:1807.00065 > 29 Jun 2018