D. Russeil

Deep H survey of the Milky Way

The Galactic plane has been observed between l= 330 to l= 336 as part of a velocity resolved H survey of the southern Milky Way using a scaning Fabry-Perot on a 36 cm telescope. The detailed analysis of the resultant H profiles reveals the presence of several layers of ionized gas with different velocities over the surveyed region. We have studied in detail both the 2-D spatial and velocity structure of the HII regions RCW102, RCW104 and RCW106. Combining these H observations with stellar and radio data we provide estimates for the most probable distances of these different layers. The first layer at -5 km is local emission linked to the Sco-Cen association at 170 pc. The next layer, around -24 km , is at 1.9 kpc and traces the near section of the Sagittarius-Carina arm. Well connected to the Sagittarius-Carina arm portions traced in the adjacent regions (l= 328 and l= 338 area), the arm, in this longitude range, clearly shows and confirms the departure from a logarithmic spiral. The Scutum-Crux arm is also traced in this area by faint and diffuse emission at -40 km which can be placed at 3.2 kpc. The layer at -52 km is the major spiral-arm feature of the studied area; its most probable stellar distance is 4.2 kpc. An important emission component is also observed at -65 km in the southern part of the surveyed area. This mainly patchy and filamentary emission we identify as the possible optical counterpart of a supernovae remnant centered at l= 332.0, b=-3.2. Finally, two complexes have been determined around 12.5 kpc which places them in the far section of the Norma arm

A deep Hα survey of the Milky Way VI. The l = 332 ◦ area ,

The Galactic plane has been observed between l= 330 to l= 336 as part of a velocity resolved H survey of the southern Milky Way using a scaning Fabry-Perot on a 36 cm telescope. The detailed analysis of the resultant H profiles reveals the presence of several layers of ionized gas with different velocities over the surveyed region. We have studied in detail both the 2-D spatial and velocity structure of the HII regions RCW102, RCW104 and RCW106. Combining these H observations with stellar and radio data we provide estimates for the most probable distances of these different layers. The first layer at -5 km is local emission linked to the Sco-Cen association at 170 pc. The next layer, around -24 km , is at 1.9 kpc and traces the near section of the Sagittarius-Carina arm. Well connected to the Sagittarius-Carina arm portions traced in the adjacent regions (l= 328 and l= 338 area), the arm, in this longitude range, clearly shows and confirms the departure from a logarithmic spiral. The Scutum-Crux arm is also traced in this area by faint and diffuse emission at -40 km which can be placed at 3.2 kpc. The layer at -52 km is the major spiral-arm feature of the studied area; its most probable stellar distance is 4.2 kpc. An important emission component is also observed at -65 km in the southern part of the surveyed area. This mainly patchy and filamentary emission we identify as the possible optical counterpart of a supernovae remnant centered at l= 332.0, b=-3.2. Finally, two complexes have been determined around 12.5 kpc which places them in the far section of the Norma arm

A Deep Hα survey of the Milky Way

An 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°.

A kinematical catalogue of HII regions and superbubbles in the LMC

We report the results of a kinematic Hα survey of the Large Magellanic Cloud (LMC) in the form of a kinematic and photometric catalogue of 210 HII regions, the radial velocity field of the ionized hydrogen in this galaxy, and the LMC Rotation Curve obtained from the velocity field. These data aim at understanding the LMC HII regions, bubbles and superbubbles in a global (galactic) scale so that we could have a 3D view and separate the rotation due to gravitational potential from other motions such as expansions.

The Multispectral Study of Galactic Plane Star-Forming Regions (Southern Hemisphere)

The Marseille Observatory Hα Survey of the southern Milky Way supplies Hα velocities of ionized hydrogen emission regions like classical HII regions and the ionized interstellar medium diffuse component. About 250 fields of the Galactic plane have been already covered with a scanning Fabry-Perot interferometer (Amram et al. 1991; Le Coarer et al. 1992).