|
| | | | |
| | | |
| Stat |
Members: 3645
Articles: 2'506'133
Articles rated: 2609
27 April 2024 |
|
| | | | |
|
Article overview
| |
|
|
Rugate filters for OH-suppressed imaging at near-infrared wavelengths | | A.R. Offer
; J. Bland-Hawthorn
; | | Date: |
28 Jul 1997 | | Subject: | astro-ph | | Affiliation: | AAO | | Abstract: | Ground-based observations at near-infrared wavelengths are severely affected by atmospheric OH bands. Many authors have recognized the potential gains in sensitivity from suppressing these features. Dispersive instruments show some promise but are both expensive and complicated to build. OH suppression filters using single or periodic notches have the advantage of simplicity but significant gains have not yet been realised. Rugate filters (with graded index inhomogeneous coatings) offer key advantages for astronomical imaging. It is possible to produce a transmission profile comprising a series of irregular and sharply defined bandpasses. We demonstrate through numerical simulation that it should be possible to achieve 95% suppression of the OH features in the J photometric band, while retaining roughly half of the spectral coverage. This would lead to extraordinary gains in sensitivity even for observations of continuum sources. In addition, these filters allow much longer exposures before the detector saturates on the sky background. (I and z-band filters can also be envisaged.) In 1" seeing, a J-band rugate filter used in conjunction with a 4m telescope would detect a J=23 continuum source at 5.0-sigma in a single 10 min exposure. In comparison, a conventional J filter requires multiple exposures for a 10 minute integration time and achieves only a 2.5-sigma detection. For emission line sources, the rugate filter has an even bigger advantage over conventional filters, with a fourfold increase in signal:noise ratio possible in certain instances. Astrophysical studies which could benefit from rugate filters are searches for very low mass stars and galaxy evolution out to z=3. | | Source: | arXiv, astro-ph/9707298 | | Services: | Forum | Review | PDF | Favorites | |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
|
News, job offers and information for researchers and scientists:
| |
REGISTER