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The Circumgalactic Medium of Andromeda

Published online by Cambridge University Press:  21 March 2017

Nicolas Lehner  and
the Project AMIGA team
Nicolas Lehner
Affiliation:
Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 email: [email protected]
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Abstract

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Our view of galaxies has been transformed in recent years with diffuse halo gas surrounding galaxies that contains at least as many metals and baryons as their disks. While single sight lines through galaxy halos seen in absorption have provided key new constraints, they provide only average properties. Our massive neighbor, the Andromeda (M31) galaxy, provides an unique way to study its circumgalactic medium whereby we can study it using not one or two, but ~36 sightlines thanks to its proximity. With our Large HST program — Project AMIGA (Absorption Maps In the Gas of Andromeda), our goals are to determine the spatial distribution of the halo properties of a L* galaxy using 36 background targets at different radii and azimuths. In this brief paper, I discuss briefly the scientific rationale of Project AMIGA and some early science results. In particular, for the first time we have demonstrated that M31 has a gaseous halo that extends to Rvir with as much as metal and baryonic masses than in its disk and has substantial change in its ionization properties with more highly ionized gas found at R ~ Rvir than cooler gas found near the disk.

Keywords

galaxies: halosgalaxies: individual (M31)Local Groupquasars: absorption lines
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 11 , Symposium S321: Formation and Evolution of Galaxy Outskirts , March 2016 , pp. 226 - 228
Copyright
Copyright © International Astronomical Union 2017 

References

Faucher-Giguère, C.-A., et al. 2015, MNRAS, 449, 987.Google Scholar
Ford, A. B., et al. 2014, MNRAS, 444, 1260.Google Scholar
Lehner, N., Howk, J. C., & Wakker, B. P. 2015, ApJ, 804, 79 Google Scholar
McConnachie, A. W., et al. 2009, Nature, 461, 66.Google Scholar
Peeples, M. S., et al. 2014, ApJ, 786, 54.Google Scholar
Stewart, K. R., et al. 2011, ApJ 735 L1.Google Scholar
Stocke, J. T., et al. 2013, ApJ, 763, 148.Google Scholar
Tumlinson, J., et al. 2011, Science, 334, 948.CrossRefGoogle Scholar
Werk, J. K., et al. 2014, ApJ, 792, 8 Google Scholar