Studying the Temperature and Ionization State of the Warm Ionized Medium

Melissa Halford; E. J. Mierkiewicz; R. J. Reynolds; G. J. Madsen; L. M. Haffner; K. A. Barger; F. L. Roesler; Lawrence Haffner

Studying the Temperature and Ionization State of the Warm Ionized Medium

Melissa Halford, E. J. Mierkiewicz, R. J. Reynolds, G. J. Madsen, L. M. Haffner, K. A. Barger, F. L. Roesler, Lawrence Haffner

Research output: Contribution to journal › Article › peer-review

Abstract

Using data from the Wisconsin Hydrogen Alpha Mapper (WHAM) and Pine Bluff Observatory's Spatial Heterodyne Spectrometer (SHS), we studied the warm ionized component of the Galaxy's interstellar medium (WIM). Line ratios of H-alpha, [N II], [O II] and [S II] emission were used to study the WIM gas in both the local spiral arm and more distant areas of the Galaxy. The strength of the [S II] line was used to measure the ionization state in a set of nine look directions and ratios of [N II]/H-alpha and [O II]/H-alpha provide a measure of temperature. Our study expands upon and confirms the results of previous [O II] studies of the WIM, which limited themselves to line ratios including only the local component of the [O II] emission. The work presented here includes a detailed component analysis of WIM emission from non-local gas in the kinematically distinct Perseus spiral arm and uses [S II] data that was not available in the previous [O II] study.

Original language	American English
Journal	217th American Astronomical Society Meeting
State	Published - Jan 2011

Keywords

Interstellar medium
Milky Way

Disciplines

Astrophysics and Astronomy

Cite this

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title = "Studying the Temperature and Ionization State of the Warm Ionized Medium",

abstract = " Using data from the Wisconsin Hydrogen Alpha Mapper (WHAM) and Pine Bluff Observatory's Spatial Heterodyne Spectrometer (SHS), we studied the warm ionized component of the Galaxy's interstellar medium (WIM). Line ratios of H-alpha, [N II], [O II] and [S II] emission were used to study the WIM gas in both the local spiral arm and more distant areas of the Galaxy. The strength of the [S II] line was used to measure the ionization state in a set of nine look directions and ratios of [N II]/H-alpha and [O II]/H-alpha provide a measure of temperature. Our study expands upon and confirms the results of previous [O II] studies of the WIM, which limited themselves to line ratios including only the local component of the [O II] emission. The work presented here includes a detailed component analysis of WIM emission from non-local gas in the kinematically distinct Perseus spiral arm and uses [S II] data that was not available in the previous [O II] study.",

keywords = "Interstellar medium, Milky Way",

author = "Melissa Halford and Mierkiewicz, {E. J.} and Reynolds, {R. J.} and Madsen, {G. J.} and Haffner, {L. M.} and Barger, {K. A.} and Roesler, {F. L.} and Lawrence Haffner",

year = "2011",

month = jan,

language = "American English",

journal = "217th American Astronomical Society Meeting",

}

TY - JOUR

T1 - Studying the Temperature and Ionization State of the Warm Ionized Medium

AU - Halford, Melissa

AU - Mierkiewicz, E. J.

AU - Reynolds, R. J.

AU - Madsen, G. J.

AU - Haffner, L. M.

AU - Barger, K. A.

AU - Roesler, F. L.

AU - Haffner, Lawrence

PY - 2011/1

Y1 - 2011/1

N2 - Using data from the Wisconsin Hydrogen Alpha Mapper (WHAM) and Pine Bluff Observatory's Spatial Heterodyne Spectrometer (SHS), we studied the warm ionized component of the Galaxy's interstellar medium (WIM). Line ratios of H-alpha, [N II], [O II] and [S II] emission were used to study the WIM gas in both the local spiral arm and more distant areas of the Galaxy. The strength of the [S II] line was used to measure the ionization state in a set of nine look directions and ratios of [N II]/H-alpha and [O II]/H-alpha provide a measure of temperature. Our study expands upon and confirms the results of previous [O II] studies of the WIM, which limited themselves to line ratios including only the local component of the [O II] emission. The work presented here includes a detailed component analysis of WIM emission from non-local gas in the kinematically distinct Perseus spiral arm and uses [S II] data that was not available in the previous [O II] study.

AB - Using data from the Wisconsin Hydrogen Alpha Mapper (WHAM) and Pine Bluff Observatory's Spatial Heterodyne Spectrometer (SHS), we studied the warm ionized component of the Galaxy's interstellar medium (WIM). Line ratios of H-alpha, [N II], [O II] and [S II] emission were used to study the WIM gas in both the local spiral arm and more distant areas of the Galaxy. The strength of the [S II] line was used to measure the ionization state in a set of nine look directions and ratios of [N II]/H-alpha and [O II]/H-alpha provide a measure of temperature. Our study expands upon and confirms the results of previous [O II] studies of the WIM, which limited themselves to line ratios including only the local component of the [O II] emission. The work presented here includes a detailed component analysis of WIM emission from non-local gas in the kinematically distinct Perseus spiral arm and uses [S II] data that was not available in the previous [O II] study.

KW - Interstellar medium

KW - Milky Way

M3 - Article

JO - 217th American Astronomical Society Meeting

JF - 217th American Astronomical Society Meeting

ER -