Please note that eDoc will be permanently shut down in the first quarter of 2021!      Home News About Us Contact Contributors Disclaimer Privacy Policy Help FAQ

Quick Search
My eDoc
Session History
Support Wiki
Direct access to
document ID:

          Institute: MPI für Astronomie     Collection: Publikationen_mpia     Display Documents

ID: 720072.0, MPI für Astronomie / Publikationen_mpia
Molecular hydrogen emission in the interstellar medium of the Large Magellanic Cloud
Authors:Naslim, N.; Kemper, F.; Madden, S. C.; Hony, S.; Chu, Y. -. H.; Galliano, F.; Bot, C.; Yang, Y.; Seok, J.; Oliveira, J. M.; van Loon, J. T.; Meixner, M.; Li, A.; Hughes, A.; Gordon, K. D.; Otsuka, M.; Hirashita, H.; Morata, O.; Lebouteiller, V.; Indebetouw, R.; Srinivasan, S.; Bernard, J. -. P.; Reach, W. T.
Date of Publication (YYYY-MM-DD):2015
Title of Journal:Monthly Notices of the Royal Astronomical Society
Issue / Number:3
Start Page:2490
End Page:2504
Audience:Not Specified
Abstract / Description:We present the detection and analysis of molecular hydrogen emission towards ten interstellar regions in the Large Magellanic Cloud. We examined low-resolution infrared spectral maps of 12 regions obtained with the Spitzer infrared spectrograph (IRS). The pure rotational 0-0 transitions of H2 at 28.2 and 17.1 μm are detected in the IRS spectra for 10 regions. The higher level transitions are mostly upper limit measurements except for three regions, where a 3σ detection threshold is achieved for lines at 12.2 and 8.6 μm. The excitation diagrams of the detected H2 transitions are used to determine the warm H2 gas column density and temperature. The single-temperature fits through the lower transition lines give temperatures in the range 86-137 K. The bulk of the excited H2 gas is found at these temperatures and contributes ˜5-17 per cent to the total gas mass. We find a tight correlation of the H2 surface brightness with polycyclic aromatic hydrocarbon and total infrared emission, which is a clear indication of photoelectric heating in photodissociation regions. We find the excitation of H2 by this process is equally efficient in both atomic- and molecular-dominated regions. We also present the correlation of the warm H2 physical conditions with dust properties. The warm H2 mass fraction and excitation temperature show positive correlations with the average starlight intensity, again supporting H2 excitation in photodissociation regions.
Free Keywords:ISM: molecules; photodissociation region (PDR); galaxies: ISM; Magellanic Cloud; infrared: ISM
External Publication Status:published
Document Type:Article
Communicated by:N. N.
Affiliations:MPI für Astronomie
The scope and number of records on eDoc is subject to the collection policies defined by each institute - see "info" button in the collection browse view.