scholarly journals Global Distribution of Far-ultraviolet Emissions from Highly Ionized Gas in the Milky Way

2019 ◽  
Vol 243 (1) ◽  
pp. 9 ◽  
Author(s):  
Young-Soo Jo ◽  
Kwang-il Seon ◽  
Kyoung-Wook Min ◽  
Jerry Edelstein ◽  
Wonyong Han ◽  
...  
Keyword(s):  
Milky Way ◽  
Global Distribution ◽  
Ionized Gas ◽  
Ultraviolet Emissions ◽  
Far Ultraviolet

Radio recombination line observations towards Spitzer infrared bubbles with the TianMa radio telescope

2019 ◽  
Vol 489 (4) ◽  
pp. 4862-4874
Author(s):  
L G Hou ◽  
X Y Gao
Keyword(s):  
Radio Telescope ◽  
Detection Rate ◽  
Milky Way ◽  
Absorption Method ◽  
Recombination Line ◽  
Ionized Gas ◽  
Radio Recombination Line ◽  
Warm Ionized Medium

ABSTRACT Many of the Spitzer infrared bubbles identified by the Milky Way Project (MWP) are suggested to be $\rm{H \small {II}} $ regions in nature. More than 70 per cent of the ∼5000 known bubbles do not have radio recombination line (RRL) observations, hence have not been confirmed as $\rm{H \small {II}} $ regions. A systematic RRL survey should be helpful to identify the nature of the bubbles. With the Shanghai TianMa 65-m radio telescope, we searched for RRLs towards 216 selected Spitzer bubbles by simultaneously observing 19 RRLs in the C band (4–8 GHz). RRLs are detected in the directions of 75 of the 216 targets. 31 of the 75 RRL sources are classified as new detections, which are possibly from new $\rm{H \small {II}} $ regions or diffuse warm ionized medium; 36 of them are probably from the outskirts of nearby bright $\rm{H \small {II}} $ regions, rather than bubble-encircled ionized gas; and the detected RRLs towards 8 bubbles are identified from known $\rm{H \small {II}} $ regions. For 58 of the 75 RRL sources, we obtained their distances after resolving the kinematic distance ambiguity by combining the results of the H2CO absorption method, the $\rm{H \small {I}} $ emission/absorption method, and the $\rm{H \small {I}} $ self-absorption method. The low detection rate of new $\rm{H \small {II}} $ regions implies that a number of MWP bubbles in the DR1 catalogue are too faint if they are $\rm{H \small {II}} $ regions.

scholarly journals The Fuse Survey of O VI in and near the Milky Way

2004 ◽  
Vol 217 ◽  
pp. 147-153
Author(s):  
B. D. Savage ◽  
B. P. Wakker ◽  
K. R. Sembach ◽  
P. Richter ◽  
M. Meade
Keyword(s):  
High Velocity ◽  
Polar Region ◽  
Milky Way ◽  
Thick Disk ◽  
Hot Gas ◽  
Tidal Interactions ◽  
Halo Stars ◽  
Absorbing Layer ◽  
Far Ultraviolet ◽  
Gas Interactions

We summarize the results of the Far-Ultraviolet Spectroscopic Explorer (FUSE) program to study O VI in the Milky Way halo. Spectra of 100 extragalactic objects and two distant halo stars are analyzed to obtain measures of O VI absorption along paths through the Milky Way thick disk/halo and beyond. Strong O VI absorption over the velocity range from −100 to 100 km s−1 reveals a widespread but highly irregular distribution of O VI, implying the existence of substantial amounts of hot gas with T~3×105 K in the Milky Way thick disk/halo. The overall distribution of O VI can be described by a plane-parallel patchy absorbing layer with an average O VI mid-plane density of no(O VI) = 1.7×10−8 cm−3, an exponential scale height of ~2.3 kpc, and a ~0.25 dex excess of O VI in the northern Galactic polar region. Approximately 60 percent of the sky is covered by high velocity O VI with |vLSR|>100 km s−1. This high velocity O VI traces a variety of phenomena in and near the Milky Way including outflowing material from the Milky Way, tidal interactions with the Magellanic Clouds, accretion of gas onto the Milky Way, and warm/hot gas interactions in a highly extended (>70 kpc) Galactic corona or with hot intergalactic gas in the Local Group.

scholarly journals Turbulence in the diffuse magneto-ionized medium: observational aspects

2015 ◽  
Vol 11 (A29B) ◽  
pp. 720-722
Author(s):  
Marijke Haverkorn
Keyword(s):  
Magnetic Fields ◽  
Milky Way ◽  
Turbulent Energy ◽  
Spectral Lines ◽  
Observational Methods ◽  
Interstellar Gas ◽  
Ionized Gas ◽  
Neutral Gas ◽  
Velocity Information ◽  
Gas Component

AbstractTurbulence in the interstellar medium is ubiquitous. The turbulent energy density in the gas is significant, and comparable to energy densities of magnetic fields and cosmic rays. Studies of the turbulent interstellar gas in the Milky Way have mostly focused on the neutral gas component, since various spectral lines can give velocity information. Probing turbulent properties in the ionized gas, let alone in magnetic fields, is observationally more difficult. A number of observational methods are discussed below which provide estimates of the maximum scale of fluctuations, the Mach number and other turbulence characteristics.

scholarly journals Deep Hα Survey of the Milky Way

1995 ◽  
Vol 149 ◽  
pp. 160-164 ◽  
Author(s):  
M. Marcelin ◽  
Y.M. Georgelin ◽  
P. Amram ◽  
Y.P. Georgelin ◽  
E. le Coarer
Keyword(s):  
Radial Velocity ◽  
Spatial Resolution ◽  
Milky Way ◽  
Galactic Plane ◽  
Ionized Gas ◽  
Kinematic Data ◽  
Radio Data ◽  
Small Telescope ◽  
Fabry Perot ◽  
Galactic Longitude

AbstractAn Hα Survey of the Milky Way is being led at La Silla with a small telescope equipped with a scanning Fabry-Perot interferometer and IPCS. This Survey gives detailed Hα maps with a 9” spatial resolution and radial velocity maps with a 5km/s resolution. About 200 fields (38’×38’) have been already observed along the galactic plane. They furnish mosaics ranging from galactic longitude 234° to 350°. Combined with distances of exciting stars and radio data our kinematic data of the ionized gas enable to draw precisely the spiral arms of our Galaxy. Examples of the results obtained are given for galactic longitudes 234°, 283°, 290°, 298°, 328° and 338°.

scholarly journals A HUGE RESERVOIR OF IONIZED GAS AROUND THE MILKY WAY: ACCOUNTING FOR THE MISSING MASS?

2012 ◽  
Vol 756 (1) ◽  
pp. L8 ◽  
Author(s):  
A. Gupta ◽  
S. Mathur ◽  
Y. Krongold ◽  
F. Nicastro ◽  
M. Galeazzi
Keyword(s):  
Milky Way ◽  
Ionized Gas ◽  
Missing Mass

scholarly journals Constraining the Extra Heating of the Diffuse Ionized Gas in the Milky Way

2005 ◽  
Vol 632 (1) ◽  
pp. 277-282 ◽  
Author(s):  
T. Elwert ◽  
R.‐J. Dettmar
Keyword(s):  
Milky Way ◽  
Ionized Gas ◽  
Diffuse Ionized Gas

scholarly journals Diffuse Ionized Gas in the Milky Way Disk

2017 ◽  
Vol 849 (2) ◽  
pp. 117 ◽  
Author(s):  
Matteo Luisi ◽  
L. D. Anderson ◽  
Dana S. Balser ◽  
Trey V. Wenger ◽  
T. M. Bania
Keyword(s):  
Milky Way ◽  
Ionized Gas ◽  
Diffuse Ionized Gas

scholarly journals Accretion Onto the Milky Way: The Smith Cloud

2015 ◽  
Vol 11 (S315) ◽  
pp. 9-12
Author(s):  
Felix J. Lockman
Keyword(s):  
Dark Matter ◽  
Angular Momentum ◽  
Stellar Population ◽  
Milky Way ◽  
Galactic Plane ◽  
Dwarf Galaxy ◽  
Dark Matter Halo ◽  
Ionized Gas ◽  
Gas Accretion

AbstractActive gas accretion onto the Milky Way is observed in an object called the Smith Cloud, which contains several million solar masses of neutral and warm ionized gas and is currently losing material to the Milky Way, adding angular momentum to the disk. It is several kpc in size and its tip lies 2 kpc below the Galactic plane. It appears to have no stellar counterpart, but could contain a stellar population like that of the dwarf galaxy Leo P. There are suggestions that its existence and survival require that it be embedded in a dark matter halo of a few 108 solar masses.

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