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 Feeding Versus Feedback in AGNs from Near-Infrared IFU Observations: The Case of Mrk 1066

2009 ◽  
Vol 5 (S267) ◽  
pp. 405-405
Author(s):  
Rogemar A. Riffel ◽  
Thaisa Storchi-Bergmann
Keyword(s):  
Spatial Resolution ◽  
Central Region ◽  
Near Infrared ◽  
Galactic Plane ◽  
Seyfert Galaxy ◽  
Active Galaxies ◽  
Molecular Gas ◽  
Field Observations ◽  
Ionized Gas ◽  
Integral Field

Previous studies of the central region of active galaxies show that the molecular and ionized gas have distinct kinematics and flux distributions, with the former dominated by quiescent kinematics characteristic of rotation in the galactic plane and the latter with more disturbed kinematics and apparently extending to larger galactic latitudes. These results suggest that the molecular gas can be a tracer of the feeding of the AGN and the ionized gas a tracer of its feedback (e.g., Riffel et al. 2009, 2008, 2006; Storchi-Bergmann et al. 2009a, b). In the present study we use Gemini NIFS integral field observations of the inner 700×700 pc2 of the Seyfert galaxy Mrk 1066 at a spatial resolution of ~ 35 pc to investigate if the above scenario is also valid for this galaxy.

scholarly journals The Structure and Kinematics of the Ionized Gas In Centaurus A

1987 ◽  
Vol 127 ◽  
pp. 417-418
Author(s):  
J. Bland ◽  
K. Taylor ◽  
P. D. Atherton
Keyword(s):  
Spatial Resolution ◽  
Spectral Resolution ◽  
High Spectral Resolution ◽  
Line Of Sight ◽  
Rotating Disc ◽  
Ionized Gas ◽  
Dust Lane ◽  
Data Cubes ◽  
Fabry Perot ◽  
Centaurus A

The TAURUS Imaging Fabry-Perot System (Taylor & Atherton 1980) has been used with the IPCS at the AAT to observe the ionized gas within NGC 5128 (Cen A) at [NII]λ6548 and Hα. Seven independent (x, y,λ) data cubes were obtained along the dust lane at high spectral resolution (30 km/s FWHM) and at a spatial resolution limited by the seeing (~1″). From these data, maps of the kinematics and intensities of the ionized gas were derived over a 420″ by 300″ region. The maps are the most complete to date for this object comprising 17500 and 5300 fitted spectra in Ha and [NII]λ6548 respectively. The dust lane system is found to be well understood in terms of a differentially rotating disc of gas and dust which is warped both along and perpendicular to the line-of-sight.

scholarly journals The Mopra Southern Galactic Plane CO Survey — Data Release 1

2015 ◽  
Vol 32 ◽  
Author(s):  
Catherine Braiding ◽  
M. G. Burton ◽  
R. Blackwell ◽  
C. Glück ◽  
J. Hawkes ◽  
...  
Keyword(s):  
Survey Data ◽  
Spatial Resolution ◽  
Spectral Resolution ◽  
Molecular Clouds ◽  
Galactic Plane ◽  
Data Archive ◽  
Data Release ◽  
Noise Statistics ◽  
Galactic Longitude

AbstractWe present observations of the first 10° of longitude in the Mopra CO survey of the southern Galactic plane, covering Galactic longitude l = 320–330° and latitude b = ±0.5°, and l = 327–330°, b = +0.5–1.0°. These data have been taken at 35-arcsec spatial resolution and 0.1 km s−1 spectral resolution, providing an unprecedented view of the molecular clouds and gas of the southern Galactic plane in the 109–115 GHz J = 1–0 transitions of 12CO, 13CO, C18O, and C17O. Together with information about the noise statistics from the Mopra telescope, these data can be retrieved from the Mopra CO website and the CSIRO-ATNF data archive.

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.

scholarly journals Unusually Wide, High-Velocity Radio Recombination Lines from G0.15–0.05 in the Radio Arc

1989 ◽  
Vol 136 ◽  
pp. 275-280 ◽  
Author(s):  
F. Yusef-Zadeh ◽  
Mark Morris ◽  
J. H. van Gorkom
Keyword(s):  
Radial Velocity ◽  
Galactic Center ◽  
Galactic Plane ◽  
Line Profiles ◽  
Recombination Line ◽  
Ionized Gas ◽  
Hii Region ◽  
Sgr A ◽  
Relativistic Particles ◽  
Kinematic Properties

The H92αrecombination line was observed at 8 GHz toward the “pistol-shaped” HII region G0.15–0.05 using the VLA2in its most compact configuration. The line profiles of individual components of this source peak at VLSR=123 km/s and have total line widths of ~90 km/s. The kinematical structure of the “pistol” is unusual in that much of the neutral and ionized gas in this region is seen predominantly at either +50 or +20 km/s. The line width and radial velocity are the largest found in the Galactic center region with the exception of Sgr A West. We also found gas at VLSR=140 km/s associated with G0.18–0.04: the sickle-shaped feature which surrounds G0.15–0.05. The kinematic properties of G0.18–0.04 and G0.15–0.05 suggest that these two features are components of a single, but complex thermal system interacting with the nonthermal filaments of the radio Arc. In this regard, the width of the broad recombination line from G0.15–0.05, and its large radial velocity, might be explained as the interaction of streaming relativistic particles in the nonthermal filaments of the Arc impacting upon ambient gas clouds lying in the Galactic plane.

scholarly journals 2D kinematics of the edge-on spiral galaxy ESO 379-006

2012 ◽  
Vol 8 (S295) ◽  
pp. 234-235
Author(s):  
M. Rosado ◽  
R. F. Gabbasov ◽  
P. Repetto ◽  
I. Fuentes-Carrera ◽  
P. Amram ◽  
...  
Keyword(s):  
Velocity Field ◽  
Radial Velocity ◽  
Rotation Curve ◽  
Minor Axis ◽  
Ionized Gas ◽  
Diffuse Ionized Gas ◽  
Fabry Perot ◽  
The Galaxy ◽  
Rotation Motion

AbstractWe present a kinematical study of the marginally edge-on galaxy ESO 379-006. With Fabry-Perot spectroscopy at Hα we obtain velocity maps, the radial velocity field, and position-velocity diagrams parallel to the major and to the minor axis of the galaxy. We build the rotation curve of the galaxy and discuss the role of projection effects. The twisting of isovelocities in the radial velocity field of the disk of ESO 379-006 as well as a kinematical asymmetry found in the position-velocity diagrams parallel to the minor axis suggest the existence of non-circular motions that can be modeled by including a radial inflow besides the rotation motion. Extraplanar Diffuse Ionized gas was detected in this galaxy both from the images and from its kinematics. It is possible that the diffuse gas is lagging in rotation.

scholarly journals Gaia-DR2 extended kinematical maps

2020 ◽  
Vol 642 ◽  
pp. A95 ◽  
Author(s):  
Ž. Chrobáková ◽  
M. López-Corredoira ◽  
F. Sylos Labini ◽  
H.-F. Wang ◽  
R. Nagy
Keyword(s):  
Dark Matter ◽  
Radial Velocity ◽  
Rotation Curve ◽  
Milky Way ◽  
Galactic Plane ◽  
Dark Matter Halo ◽  
Disk Galaxies ◽  
Modified Newtonian Dynamics ◽  
Outer Disk ◽  
Gaia Dr2

Context. Recent statistical deconvolution methods have produced extended kinematical maps in a range of heliocentric distances that are a factor of two to three larger than those analysed in Gaia Collaboration (2018, A&A, 616, A11) based on the same data. Aims. In this paper, we use such maps to derive the rotation curve both in the Galactic plane and in off-plane regions and to analyse the density distribution. Methods. By assuming stationary equilibrium and axisymmetry, we used the Jeans equation to derive the rotation curve. Then we fit it with density models that include both dark matter and predictions of the MOND (Modified Newtonian dynamics) theory. Since the Milky Way exhibits deviations from axisymmetry and equilibrium, we also considered corrections to the Jeans equation. To compute such corrections, we ran N-body experiments of mock disk galaxies where the departure from equilibrium becomes larger as a function of the distance from the centre. Results. The rotation curve in the outer disk of the Milky Way that is constructed with the Jeans equation exhibits very low dependence on R and z and it is well-fitted both by dark matter halo and MOND models. The application of the Jeans equation for deriving the rotation curve, in the case of the systems that deviate from equilibrium and axisymmetry, introduces systematic errors that grow as a function of the amplitude of the average radial velocity. In the case of the Milky Way, we can observe that the amplitude of the radial velocity reaches ∼10% that of the azimuthal one at R ≈ 20 kpc. Based on this condition, using the rotation curve obtained from the Jeans equation to calculate the mass may overestimate its measurement.

scholarly journals Magnetic Fields in the Milky Way Halo

2012 ◽  
Vol 10 (H16) ◽  
pp. 403-403 ◽  
Author(s):  
S. A. Mao ◽  
N. M. McClure-Griffiths ◽  
B. M. Gaensler ◽  
J. C. Brown ◽  
C. L. van Eck ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Milky Way ◽  
Galactic Plane ◽  
Reverse Direction ◽  
Galactic Latitude ◽  
Azimuthal Magnetic Field ◽  
Latitude Range ◽  
Rotation Measure ◽  
Galactic Longitude ◽  
Milky Way Halo

AbstractWe present a study of the Milky Way halo magnetic field, determined from observations of Faraday rotation measure (RM) of extragalactic radio sources (EGS) in Galactic longitude range 100°–117° within 30° of the Galactic plane. We find negative median RMs in both the northern and southern Galactic hemispheres for |b|>15°, outside the latitude range where the disk field dominates. This suggest that the halo magnetic field towards the outer Galaxy does not reverse direction across the mid-plane. An azimuthal magnetic field at heights 0.8−2 kpc above/below the Galactic plane between the local and the Perseus spiral arm can reproduce the observed trend of RM against Galactic latitude. We propose that the Milky Way could have a halo magnetic field similar to that observed in M51.

Variation of the amount of hydrogen along the galactic ridge

1967 ◽  
Vol 31 ◽  
pp. 171-172
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Surface Brightness ◽  
Milky Way ◽  
Neutral Hydrogen ◽  
Line Of Sight ◽  
Optical Surface ◽  
Hydrogen Density ◽  
Continuous Radiation ◽  
Galactic Longitude

The integralNHof neutral-hydrogen density along the line of sight is determined from the Kootwijk and Sydney surveys. The run ofNHwith galactic longitude agrees well with that of thermal continuous radiation and that of the optical surface brightness of the Milky Way.

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.

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