Detailed studies of stellar populations in the halos of the Milky Way and the
Andromeda (M 31) galaxies have shown increasing numbers of tidal streams and
dwarf galaxies, attesting to a complicated and on-going process of hierarchical
structure formation. The most prominent feature in the halo of M 31 is the
Giant Stellar Stream, a structure ~4.5 degrees in extent along the sky, which
is close to, but not coincident with the galaxy's minor axis. The stars that
make up this stream are kinematically and chemically distinct from the other
stars in the halo. Here, we present HST/COS high-resolution ultraviolet
absorption spectra of three Active Galactic Nuclei sight lines which probe the
M 31 halo, including one that samples gas in the main southwestern portion of
the Giant Stream. We see two clear absorption components in many metal species
at velocities typical of the M 31 halo and a third, blue-shifted component
which arises in the stream. Photoionization modeling of the column density
ratios in the different components shows gas in an ionization state typical of
that seen in other galaxy halo environments and suggests solar to slightly
super-solar metallicity, consistent with previous findings from stellar
spectroscopy.
Description
[1506.00635] A Detection of Gas Associated with the M 31 Stellar Stream
%0 Generic
%1 koch2015detection
%A Koch, Andreas
%A Danforth, Charles W.
%A Rich, R. Michael
%A Ibata, Rodrigo
%A Keeney, Brian A.
%D 2015
%K gas m31 stellar stream
%T A Detection of Gas Associated with the M 31 Stellar Stream
%U http://arxiv.org/abs/1506.00635
%X Detailed studies of stellar populations in the halos of the Milky Way and the
Andromeda (M 31) galaxies have shown increasing numbers of tidal streams and
dwarf galaxies, attesting to a complicated and on-going process of hierarchical
structure formation. The most prominent feature in the halo of M 31 is the
Giant Stellar Stream, a structure ~4.5 degrees in extent along the sky, which
is close to, but not coincident with the galaxy's minor axis. The stars that
make up this stream are kinematically and chemically distinct from the other
stars in the halo. Here, we present HST/COS high-resolution ultraviolet
absorption spectra of three Active Galactic Nuclei sight lines which probe the
M 31 halo, including one that samples gas in the main southwestern portion of
the Giant Stream. We see two clear absorption components in many metal species
at velocities typical of the M 31 halo and a third, blue-shifted component
which arises in the stream. Photoionization modeling of the column density
ratios in the different components shows gas in an ionization state typical of
that seen in other galaxy halo environments and suggests solar to slightly
super-solar metallicity, consistent with previous findings from stellar
spectroscopy.
@misc{koch2015detection,
abstract = {Detailed studies of stellar populations in the halos of the Milky Way and the
Andromeda (M 31) galaxies have shown increasing numbers of tidal streams and
dwarf galaxies, attesting to a complicated and on-going process of hierarchical
structure formation. The most prominent feature in the halo of M 31 is the
Giant Stellar Stream, a structure ~4.5 degrees in extent along the sky, which
is close to, but not coincident with the galaxy's minor axis. The stars that
make up this stream are kinematically and chemically distinct from the other
stars in the halo. Here, we present HST/COS high-resolution ultraviolet
absorption spectra of three Active Galactic Nuclei sight lines which probe the
M 31 halo, including one that samples gas in the main southwestern portion of
the Giant Stream. We see two clear absorption components in many metal species
at velocities typical of the M 31 halo and a third, blue-shifted component
which arises in the stream. Photoionization modeling of the column density
ratios in the different components shows gas in an ionization state typical of
that seen in other galaxy halo environments and suggests solar to slightly
super-solar metallicity, consistent with previous findings from stellar
spectroscopy.},
added-at = {2015-06-03T10:19:36.000+0200},
author = {Koch, Andreas and Danforth, Charles W. and Rich, R. Michael and Ibata, Rodrigo and Keeney, Brian A.},
biburl = {https://www.bibsonomy.org/bibtex/2d6f71d45f2a7c69d2d65fa4a077f2e79/miki},
description = {[1506.00635] A Detection of Gas Associated with the M 31 Stellar Stream},
interhash = {75b93e0d4a996462de0189504ee584ad},
intrahash = {d6f71d45f2a7c69d2d65fa4a077f2e79},
keywords = {gas m31 stellar stream},
note = {cite arxiv:1506.00635Comment: 10 pages, 5 figures, accepted for publication in the Astrophysical Journal},
timestamp = {2015-06-03T10:19:36.000+0200},
title = {A Detection of Gas Associated with the M 31 Stellar Stream},
url = {http://arxiv.org/abs/1506.00635},
year = 2015
}