GMTNIRS: progress toward the Giant Magellan Telescope near-infrared spectrograph

Jaffe, D. T.; Barnes, Stuart; Brooks, Cynthia B.; Lee, Hanshin; Mace, Gregory N.; Pak, Soojong; Park, Byeong-Gon; Park, Chan

doi:10.1117/12.2232994

Cited by 14 publications

(8 citation statements)

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“…1.9, [49]: multi-object spectrograph for Astrophysics, inter galactic medium, and cosmology. G-CLEF [50]: GMT consortium large earth finder; GMTIFS [51]: GMT integral-field spectrograph; GMACS [52]: GMT multi-object astronomical and cosmological spectrograph; GMTNIRS [53]: GMT near-infrared spectrograph. NFIRAOS [54]: narrow-field infrared AO system; IRIS [55]:infrared imager and spectrograph; IRMS [56]:infrared multi-object spectrograph; TMT-AGE [57]: TMT analyzer for galaxies in the early universe; WFOS: wide-field optical spectrometer.…”

Section: Error Budget In Aomentioning

confidence: 99%

Projected Pupil Plane Pattern: an alternative LGS wavefront sensing technique

Yang

Bharmal

Myers

2018

Monthly Notices of the Royal Astronomical Society

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The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any wayThe full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Abstract For the next generation of extremely large telescopes, Focal Anisoplanatism (FA) renders single Laser Guide Star AO useless. Here we analyze a novel LGS alternative configuration with corresponding wavefront sensing and reconstruction method, termed Projected Pupil Plane Pattern, to solve the problem of Focal Anisoplanatism. With PPPP, turbulence is sensed during uplink by a laser beam projected as a collimated beam from the whole telescope primary mirror. Phase changes due to the turbulence introduce intensity variations that then increase in amplitude with propagation distance. By observing the distribution of intensity at two distant planes, the Transport-of-Intensity equation can be used to determine the phase aberration encountered during the uplink path. A simple imaging camera can then be used to measure the wavefront by imaging the backscattered light patterns. We have successfully demonstrated PPPP works both by simulation and laboratory experiment, where we find that PPPP can achieve equivalent performance to a SH WFS associated with a NGS. However it is shown that the main problem of PPPP is its low Signal-to-Noise Ratio if a 20 W laser is used. To reduce the requirement for high laser power, an alternative reconstructor based upon nonlinear Artificial Neural Networks has been developed, and provides a wavefront with measurement error around 160 nm RMS with a single 200 W laser on a 4-m diameter telescope. PPPP is therefore ready for a practical onsky test, which we are currently undertaking at Electro Optical Systems (EOS) Debris Laser Ranging (DLR) system, Australia. Supervisors: Nazim Bharmal and Richard Myers ii Acknowledgements I acknowledge financial support from China Scholarship Council (CSC) for covering the living expenses during my first three years of study, and from Durham University for my last year, as well as the funding of STFC for my PhD project.

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Section: Error Budget In Aomentioning

confidence: 99%

Projected Pupil Plane Pattern: an alternative LGS wavefront sensing technique

Yang

Bharmal

Myers

2018

Monthly Notices of the Royal Astronomical Society

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“…The host star in HD 23079 is relatively bright ( ; Anderson & Francis 2012), but the direct imaging method proposed by Vanderburg et al (2018) would allow the analysis of the much fainter reflected light from the planet, which would be much more limited in precision ( 1 500 m s –1 ). However, large (30 m class) telescopes (e.g., Giant Magellan Telescope; Jaffe et al 2016) are on the horizon and should be available in the foreseeable future. They would make Doppler surveys of directly imaged planets attainable due to the much larger S/N compared to current technology affecting the RV precision (Quanz et al 2015).…”

Section: Resultsmentioning

confidence: 99%

“…As the transit method is unavailable for finding exomoons in HD 23079, Doppler monitoring within direct imaging observations might offer positive outcomes. Note that large (30 m class) telescopes (e.g., Giant Magellan Telescope; Jaffe et al 2016) should be available in the foreseeable future. The much larger S/N from telescopes with a large mirror would make Doppler surveys of directly imaged planets attainable, where the Keplerian signals from Earth-mass exomoons with an RV semi-amplitude greater than 100 m s –1 would be possible (Vanderburg et al 2018).…”

Section: Discussionmentioning

confidence: 99%

Updated studies on exomoons in the HD 23079 system

Jagtap

Quarles

Cuntz

2021

Publ. Astron. Soc. Aust.

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We re-evaluate the outer edge of orbital stability for possible exomoons orbiting the radial velocity planet discovered in the HD 23079 system. In this system, a solar-type star hosts a Jupiter-mass planet in a nearly circular orbit in the outer stellar habitable zone. The outer stability limit of exomoons is deduced using N-body and tidal migration simulations considering a large range of initial conditions, encompassing both prograde and retrograde orbits. In particular, we extend previous works by evaluating many values in the satellite mean anomaly to identify and exclude regions of quasi-stability. Future observations of this system can make use of our results through a scale factor relative to the currently measured minimum mass. Using a constant time lag tidal model (Hut 1981), we find that plausible tidal interactions within the system are insufficient to induce significant outward migration toward the theoretical stability limit. While current technologies are incapable of detecting exomoons in this system, we comment on the detectability of putative moons through Doppler monitoring within direct imaging observations in view of future research capacities.

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“…In this paper, we present an overview of those developments for the first generation instrument suite. Details of the individual instrument designs and their status can be found elsewhere in these procedings 3,4,5,6,7 . We also describe a modest optical imager that recently has been added to the first generation of instruments, as well as several early ideas for future instruments.…”

Section: Introductionmentioning

confidence: 99%

Instrumentation progress at the Giant Magellan Telescope project

Jacoby

Bernstein

Bouchez³

et al. 2016

SPIE Proceedings

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Instrument development for the 24m Giant Magellan Telescope (GMT) is described: current activities, progress, status, and schedule. One instrument team has completed its preliminary design and is currently beginning its final design (G-CLEF, an optical 350-950 nm, high-resolution and precision radial velocity echelle spectrograph). A second instrument team is in its conceptual design phase (GMACS, an optical 350-950 nm, medium resolution, 6-10 arcmin field, multiobject spectrograph). A third instrument team is midway through its preliminary design phase (GMTIFS, a near-IR YJHK diffraction-limited imager/integral-field-spectrograph), focused on risk reduction prototyping and design optimization. A fourth instrument team is currently fabricating the 5 silicon immersion gratings needed to begin its preliminary design phase (GMTNIRS, a simultaneous JHKLM high-resolution, AO-fed, echelle spectrograph). And, another instrument team is focusing on technical development and prototyping (MANIFEST, a facility robotic, multifiber-feed, with a 20 arcmin field of view). In addition, a medium-field (6 arcmin, 0.06 arcsec/pix) optical imager will support telescope and AO commissioning activities, and will excel at narrow-band imaging. In the spirit of advancing synergies with other groups, the challenges of running an ELT instrument program and opportunities for cross-ELT collaborations are discussed.

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GMTNIRS: progress toward the Giant Magellan Telescope near-infrared spectrograph

Cited by 14 publications

References 0 publications

Projected Pupil Plane Pattern: an alternative LGS wavefront sensing technique

Projected Pupil Plane Pattern: an alternative LGS wavefront sensing technique

Updated studies on exomoons in the HD 23079 system

Instrumentation progress at the Giant Magellan Telescope project

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