Interstellar gas within  ~10 pc of Sagittarius A^∗

Abstract

Aims. We seek to obtain a coherent and realistic three-dimensional picture of the interstellar gas out to about 10 pc of the dynamical center of our Galaxy, which is supposed to be at Sgr A * . Methods. We review the existing observational studies on the different gaseous components that have been identified near Sgr A * , and retain all the information relating to their spatial configuration and/or physical state. Based on the collected information, we propose a three-dimensional representation of the interstellar gas, which describes each component in terms of both its precise location and morphology and its thermodynamic properties. Results. The interstellar gas near Sgr A * can be represented by five basic components, which are, by order of increasing size: (1) a central cavity with roughly equal amounts of warm ionized and atomic gases; (2) a ring of mainly molecular gas; (3) a supernova remnant filled with hot ionized gas; (4) a radio halo of warm ionized gas and relativistic particles; and (5) a belt of massive molecular clouds. While the halo gas fills ≈80% of the studied volume, the molecular components enclose ≈98% of the interstellar mass.

The OH-streamer in Sagittarius A revisited: analysis of hydroxyl absorption within 10 pc from the Galactic centre

“…The material between the clumps in the OH-streamer are not considered, such that the mass of the OH-streamer is considered as a lower limit. The value of n H 2 is taken as 10 5 cm −3 , which is in the lower range for molecular gas in the CND found in Ferrière (2012). We derive at a total mass of 400 M for the OH-streamer and about 2500 M for the more massive +80 km s −1 cloud (Table 1).…”

“…General reviews of the Galactic centre (GC) region have been presented by Mezger et al (1996) and Morris & Serabyn (1996), among others, and an up-to-date introduction to the Sgr A complex is given by Ferrière (2012).…”

When dark matter interacts with cosmic rays or interstellar matter: A morphological study

“…In each case, use of either a contracted NFW or Einasto profile would lead to a slightly brighter and cuspier, or fainter and more cored profile in the innermost regions and each template has been normalized to its maximal value, with no other salient differences. The F07 gas model possesses a very bright central core due to the highly concentrated CMZ zone surrounding the galactic nucleus (not to be confused with the even denser circumnuclear ring [51] which occupies the innermost ≈10 pc and is below the scale probed here). Emission from the bulge disk can be seen in the diagonally oriented flares on either side.…”

The chemistry and kinematics of two molecular clouds near Sagittarius A*

“…In Fig. 1, we have reproduced a model of di erent structures in the region found in Ferrière (2012), made from many past observational studies of the Galactic Centre. It shows the relative positions and interplay between molecular and ionised components within 10 pc of Sgr A*, such as the supernova remnant, molecular clouds and the circumnuclear molecular ring, to illustrate our current understanding of them.…”