eCite Digital Repository
Excitation temperature of the warm neutral medium as a new probe of the Lyα radiation field
Citation
Murray, CE and Lindner, RR and Stanimirovic, S and Goss, WM and Heiles, C and Dickey, J and Pingel, NM and Lawrence, A and Jencson, J and Babler, BL and Hennebelle, P, Excitation temperature of the warm neutral medium as a new probe of the Lyα radiation field, Astrophysical Journal Letters, 781, (2) Article L41. ISSN 2041-8205 (2014) [Refereed Article]
 | PDF Restricted - Request a copy 194Kb |
Copyright Statement
Copyright 2014 The American Astronomical Society
DOI: doi:10.1088/2041-8205/781/2/L41
Abstract
We use the Karl G. Jansky Very Large Array to conduct a high-sensitivity survey of neutral hydrogen (HI)
absorption in the Milky Way. In combination with corresponding HI emission spectra obtained mostly with
the Arecibo Observatory, we detect a widespread warm neutral medium component with excitation temperature
(Ts) = 7200+1800-1200 K (68% confidence). This temperature lies above theoretical predictions based on collisional
excitation alone, implying that Lya scattering, the most probable additional source of excitation, is more important
in the interstellar medium (ISM) than previously assumed. Our results demonstrate that HI absorption can be used
to constrain the Lya radiation field, a critical quantity for studying the energy balance in the ISM and intergalactic
medium yet notoriously difficult to model because of its complicated radiative transfer, in and around galaxies
nearby and at high redshift.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | ISM: clouds;ISM: structure |
| Research Division: | Physical Sciences |
| Research Group: | Astronomical sciences |
| Research Field: | Galactic astronomy |
| Objective Division: | Expanding Knowledge |
| Objective Group: | Expanding knowledge |
| Objective Field: | Expanding knowledge in the physical sciences |
| UTAS Author: | Dickey, J (Professor John Dickey) |
| ID Code: | 89255 |
| Year Published: | 2014 |
| Web of Science® Times Cited: | 19 |
| Deposited By: | Mathematics and Physics |
| Deposited On: | 2014-02-27 |
| Last Modified: | 2022-08-31 |
| Downloads: | 0 |
Repository Staff Only: item control page