Bibcode
Martín-Fernández, P.; Jiménez-Vicente, Jorge; Zurita, Almudena; Mediavilla, E.; Castillo-Morales, África
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 461, Issue 1, p.6-21
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9
2016
Citations
11
Refereed citations
10
Description
We present a detailed study of the neutral and ionized gas phases in the
galactic wind for the nearby starburst galaxy NGC 5394 based on new
integral field spectroscopy obtained with the INTEGRAL fibre system at
the William Herschel Telescope. The neutral gas phase in the wind is
detected via the interstellar Na I D doublet absorption. After a careful
removal of the stellar contribution to these lines, a significant amount
of neutral gas (˜107 M⊙) is detected in
a central region of ˜1.75 kpc size. This neutral gas is
blueshifted by ˜165 km s-1 with respect to the
underlying galaxy. The mass outflow of neutral gas is comparable to the
star formation rate of the host galaxy. Simultaneously, several emission
lines (Hα, [N II], [S II]) are also analysed looking for the
ionized warm phase counterpart of the wind. A careful kinematic
decomposition of the line profiles reveals the presence of a secondary,
broader, kinematic component. This component is found roughly in the
same region where the Na I D absorption is detected. It presents higher
[N II]/Hα and [S II]/Hα line ratios than the narrow
component at the same locations, indicative of contamination by shock
ionization. This secondary component also presents blueshifted
velocities, although smaller than those measured for the neutral gas,
averaging to ˜-30 km s-1. The mass and mass outflow
rate of the wind is dominated by the neutral gas, of which a small
fraction might be able to escape the gravitational potential of the host
galaxy. The observations in this system can be readily understood within
a bipolar gas flow scenario.