Wide-field ultra-narrow-bandpass imaging with the Dragonfly Telephoto Array

Deborah M. Lokhorst; Roberto G. Abraham; Pieter van Dokkum; Seery Chen

doi:10.1117/12.2561162

13 December 2020 Wide-field ultra-narrow-bandpass imaging with the Dragonfly Telephoto Array

Deborah M. Lokhorst, Roberto G. Abraham, Pieter van Dokkum, Seery Chen

Proceedings Volume 11445, Ground-based and Airborne Telescopes VIII; 1144527 (2020) https://doi.org/10.1117/12.2561162
Event: SPIE Astronomical Telescopes + Instrumentation, 2020, Online Only

Abstract

We describe plans for adding a wide-field narrow-band imaging capability to the Dragon y Telephoto Array. Our plans focus on the development of the ‘Dragon y Filter-Tilter', a device which places ultra-narrow bandpass interference filters (Δλ ≈1 nm) in front of each of the lenses that make up the array. The filters are at the entrance pupil of the optical system, rather than in a converging beam, so their performance is not degraded by a converging light cone. This allows Dragon y to image with a spectral bandpass that is an order of magnitude narrower than that of telescopes using conventional narrow-band filters, resulting in a large increase in the contrast and detectability of extended low surface brightness line emission. By tilting the filters, the central wavelength of the transmission curve can be tuned over a range of 7 nm, corresponding to a physical distance range of about 20 Mpc for extragalactic targets. A further benefit of our approach is that it allows off-band observations to be obtained at the same time as on-band observations, so systematic errors introduced by rapid sky variability can be removed with high precision. Taken together, these characteristics should give our imaging system the ability to detect extremely faint low-surface brightness line emission. Future versions of the Dragon y Telephoto Array may have the sensitivity needed to directly image the circumgalactic medium of local galaxies. In this paper, we provide a detailed description of the concept, and present laboratory measurements that are used to verify the key ideas behind the instrument.

Conference Presentation

Citation Download Citation

Deborah M. Lokhorst, Roberto G. Abraham, Pieter van Dokkum, and Seery Chen "Wide-field ultra-narrow-bandpass imaging with the Dragonfly Telephoto Array", Proc. SPIE 11445, Ground-based and Airborne Telescopes VIII, 1144527 (13 December 2020); https://doi.org/10.1117/12.2561162

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available