Gas infall towards Sgr A* from the clumpy circumnuclear disk

Details Gas infall towards Sgr A* from the clumpy circumnuclear disk Gas infall towards Sgr A* from the clumpy circumnuclear disk

2009-03-05

arxiv.org/abs/0903.0886v1

Astrophys.J.695:1477-1494,2009

Astronomy and Astrophysics

Astrophysics

Galaxy Astrophysics

35 pages, 25 figures, 2 tables, accepted for publication in ApJ, emulate-apj style

Scientific paper

10.1088/0004-637X/695/2/1477

We present the first large-scale mosaic performed with the Submillimeter Array (SMA) in the Galactic center. We have produced a 25-pointing mosaic, covering a ~2' x 2' area around Sgr A*. We have detected emission from two high-density molecular tracers, HCN(4-3) and CS(7-6), the latter never before reported in this region. The data have an angular resolution of 4.6" x 3.1", and the spectral window coverage is from -180 km/s to 1490 km/s for HCN(4-3) and from -1605 km/s to 129 km/s for CS(7-6). Both molecular tracers present a very clumpy distribution along the circumnuclear disk (CND), and are detected with a high signal-to-noise ratio in the southern part of the CND, while they are weaker towards the northern part. Assuming that the clumps are as close to the Galactic center as their projected distances, they are still dense enough to be gravitationally stable against the tidal shear produced by the supermassive black hole. Therefore, the CND is a non-transient structure. This geometrical distribution of both tracers suggests that the southern part of the CND is denser than the northern part. Also, by comparing the HCN(4-3) results with HCN(1-0) results we can see that the northern and the southern parts of the CND have different excitation levels, with the southern part warmer than the northern. Finally, we compare our results with those obtained with the detection of NH3, which traces the warmer and less dense material detected in the inner cavity of the CND. We suggest that we are detecting the origin point where a portion of the CND becomes destabilized and approaches the dynamical center of the Milky Way, possibly being impacted by the southern streamer and heated on its way inwards.

Affiliated with

Also associated with

No associations

Rating

Gas infall towards Sgr A* from the clumpy circumnuclear disk 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 Gas infall towards Sgr A* from the clumpy circumnuclear disk, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gas infall towards Sgr A* from the clumpy circumnuclear disk will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-114469