Turbulence in the Warm Ionized Medium: Angular Broadening Toward the Galactic Center and Anticenter

Details Turbulence in the Warm Ionized Medium: Angular Broadening Toward the Galactic Center and Anticenter Turbulence in the Warm Ionized Medium: Angular Broadening Toward the Galactic Center and Anticenter

Dec 1995

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995aas...187.5901l&link_type=abstract

American Astronomical Society, 187th AAS Meeting, #59.01; Bulletin of the American Astronomical Society, Vol. 27, p.1370

Astronomy and Astrophysics

Astronomy

Scientific paper

We use angular broadening measurements to trace the strength of microtubulence in, and the associated energy deposition (e.g. stellar winds, supernovae) into, the warm ionized medium (WIM) in the Galaxy. [Galactic center] The radial distance to the region responsible for the enhanced, anisotropic angular broadening of Sgr A(*) and nearby OH/IR stars is unconstrained. If this region is an unrelated superposition gtrsim 1 kpc from Sgr A(*) , extragalactic sources seen through the region should be ~ 1arcsec , roughly double the OH/IR source sizes. If the region is a consequence of the extreme properties of the Galactic center and ~ 100 pc from Sgr A(*) , extragalactic sources should be much larger, ~ 2 arcmin. Using VLA observations of 10 fields within 5°\ of Sgr A(*) , we have identified over 100 sources. Within ~ 1deg of Sgr A(*) , we find a paucity of sources; this deficit indicates a scattering region local to the Galactic center, < 500 pc, resulting in sources being resolved out by our observations. We discuss likely agents for this enhanced scattering. [Anticenter] The radial scale length of the WIM, which appears to extend well beyond the solar circle, remains largely unconstrained, because the vast majority of scattering observations has been toward the inner Galaxy. Ionized gas at distances ~ 50 kpc is suggested by the appearance of the {H}i disks of nearby galaxies and models of low-redshift quasar absorption systems and Galactic ``fountains.'' We have used the VLBA to observe twelve extragalactic sources between 155deg < l < 210deg . Seven sources are at b < 1deg ; these lines of sight probe considerable path lengths, if the WIM extends to large distances. Five sources are at b < 10deg ; these lines of sight are sensitive to flaring or warping of the WIM in the outer Galaxy. We find source sizes consistent with a scale length ~ 20 kpc.

Affiliated with

Also associated with

No associations

Rating

Turbulence in the Warm Ionized Medium: Angular Broadening Toward the Galactic Center and Anticenter does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Turbulence in the Warm Ionized Medium: Angular Broadening Toward the Galactic Center and Anticenter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Turbulence in the Warm Ionized Medium: Angular Broadening Toward the Galactic Center and Anticenter will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1254746