Book contents
- Frontmatter
- Contents
- Preface
- Conference participants
- Conference photograph / poster
- 1 Physics of H2 and HD
- 2 Formation - Destruction
- 3 Observations and Models
- Non Stationary C-shocks: H2 Emission in Molecular Outflows
- The Ortho/Para Ratio in C and J-type Shocks
- Theoretical Models of Photodissociation Fronts
- ISO Spectroscopy of H2 in Star Forming Regions
- Observations of the H2 Ortho-Para Ratio in Photodissociation Regions
- H2 Emission from CRL618
- Hydrogen in Photodissociation Regions: NGC2023 and NGC7023
- A Pre-FUSE View of H2
- H2 Absorption Line Measurements with ORFEUS
- Ultraviolet Observations of Molecular Hydrogen in Interstellar Space
- FUSE and Deuterated Molecular Hydrogen
- ISO-SWS Observations of H2 in Galactic Sources
- H2 in Molecular Supernova Remnants
- 3D Integral Field H2 Spectroscopy in Outflows
- Near-Infrared Imaging and [OI] Spectroscopy of IC443 using 2MASS and ISO
- ISOCAM Spectro-imaging of the Supernova Remnant IC443
- Spatial Structure of a Photo-Dissociation Region in Ophiucus
- Tracing H2 Via Infrared Dust Extinction
- The Small Scale Structure of H2 Clouds
- Hot Chemistry in the Cold Diffuse Medium: Spectral Signature in the H2 Rotational Lines
- H2 Observations of the OMC-1 Outflow with the ISO-SWS
- 4 Extragalactic and Cosmology
- 5 Outlook
- Author index
Ultraviolet Observations of Molecular Hydrogen in Interstellar Space
from 3 - Observations and Models
Published online by Cambridge University Press: 04 August 2010
- Frontmatter
- Contents
- Preface
- Conference participants
- Conference photograph / poster
- 1 Physics of H2 and HD
- 2 Formation - Destruction
- 3 Observations and Models
- Non Stationary C-shocks: H2 Emission in Molecular Outflows
- The Ortho/Para Ratio in C and J-type Shocks
- Theoretical Models of Photodissociation Fronts
- ISO Spectroscopy of H2 in Star Forming Regions
- Observations of the H2 Ortho-Para Ratio in Photodissociation Regions
- H2 Emission from CRL618
- Hydrogen in Photodissociation Regions: NGC2023 and NGC7023
- A Pre-FUSE View of H2
- H2 Absorption Line Measurements with ORFEUS
- Ultraviolet Observations of Molecular Hydrogen in Interstellar Space
- FUSE and Deuterated Molecular Hydrogen
- ISO-SWS Observations of H2 in Galactic Sources
- H2 in Molecular Supernova Remnants
- 3D Integral Field H2 Spectroscopy in Outflows
- Near-Infrared Imaging and [OI] Spectroscopy of IC443 using 2MASS and ISO
- ISOCAM Spectro-imaging of the Supernova Remnant IC443
- Spatial Structure of a Photo-Dissociation Region in Ophiucus
- Tracing H2 Via Infrared Dust Extinction
- The Small Scale Structure of H2 Clouds
- Hot Chemistry in the Cold Diffuse Medium: Spectral Signature in the H2 Rotational Lines
- H2 Observations of the OMC-1 Outflow with the ISO-SWS
- 4 Extragalactic and Cosmology
- 5 Outlook
- Author index
Summary
Molecular hydrogen is the most abundant constituent in interstellar space, but is difficult to observe in its most common form. Because H2 has no dipole moment, it does not have allowed rotational or vibrational transitions and therefore in its cold, unexcited state it has no radio or infrared spectral features. Therefore the most sensitive method for detecting cold H2 is through its allowed electronic bands, which lie in the far-ultraviolet portion of the spectrum. Previous UV instruments have provided some information on far-UV spectra of cold H2, but all were limited in either throughput or spectral resolving power, or both. The current FUSE mission has a combination of high throughput and moderately high spectral resolution, and is providing information on molecular hydrogen in interstellar regimes that have been previously unexplored. This review summarizes previous UV observations of H2 and then gives an overview of early FUSE results, with an emphasis on H2 in translucent clouds.
Introduction
The mass in the galactic interstellar medium is dominated by molecular hydrogen, which begins to outweigh atomic hydrogen in diffuse clouds and is expected to become completely dominant for translucent and dense clouds; i.e. clouds having visual extinctions greater than about Av = 2 magnitudes. Even in diffuse clouds, H2 is important, playing a crucial role in cloud chemical and physical processes.
Despite the importance of understanding H2 and its distribution, physics, and chemistry, relatively little direct information is available because of the obtuse spectroscopic properties of the molecule.
- Type
- Chapter
- Information
- Molecular Hydrogen in Space , pp. 171 - 178Publisher: Cambridge University PressPrint publication year: 2000
- 1
- Cited by