English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

To determine the properties of the ionized gas at the edge of the CMZ nearSgr E we observed a small portion of the edge of the CMZ near Sgr E withspectrally resolved [C II] 158 micron and [N II] 205 micron fine structurelines at six positions with the GREAT instrument on SOFIA and in [C II] usingHerschel HIFI on-the-fly strip maps. We use the [N II] spectra along with aradiative transfer model to calculate the electron density of the gas and the[C II] maps to illuminate the morphology of the ionized gas and model thecolumn density of CO-dark H2. We detect two [C II] and [N II] velocitycomponents, one along the line of sight to a CO molecular cloud at -207 km/sassociated with Sgr E and the other at -174 km/s outside the edge of another COcloud. From the [N II] emission we find that the average electron density is inthe range of about 5 to 25 cm{-3} for these features. This electron density ismuch higher than that of the warm ionized medium in the disk. The columndensity of the CO-dark H$_2$ layer in the -207 km/s cloud is about 1-2X10{21}cm{-2} in agreement with theoretical models. The CMZ extends further out inGalactic radius by 7 to 14 pc in ionized gas than it does in molecular gastraced by CO. The edge of the CMZ likely contains dense hot ionized gassurrounding the neutral molecular material. The high fractional abundance of N+and high electron density require an intense EUV field with a photon flux oforder 1e6 to 1e7 photons cm{-2} s{-1}, and/or efficient proton charge exchangewith nitrogen, at temperatures of order 1e4 K, and/or a large flux of X-rays.Sgr E is a region of massive star formation which are a potential sources ofthe EUV radiation that can ionize the gas. In addition X-ray sources and thediffuse X-ray emission in the CMZ are candidates for ionizing nitrogen.

Ionized gas at the edge of the Central Molecular Zone