The next major advancement in astronomy and cosmology will be driven by deep observations using very sensitive telescopes with high spatial and spectral resolution capabilities. An international consortium of astronomers, including Indian astronomers are building the Thirty Meter Telescope to achieve breakthroughs in different areas of astronomy starting from studies of the solar system to that of the early universe. This article provides a brief overview of the telescope, science objectives and details of the first light instruments.
NFIRAOS, the Thirty Meter Telescope's first adaptive optics system is an order 60x60 Multi-Conjugate AO system with two deformable mirrors. Although most observing will use 6 laser guide stars, it also has an NGS-only mode. Uniquely, NFIRAOS is cooled to -30 C to reduce thermal background. NFIRAOS delivers a 2-arcminute beam to three client instruments, and relies on up to three IR WFSs in each instrument. We present recent work including: robust automated acquisition on these IR WFSs; trade-off studies for a common-size of deformable mirror; real-time computing architectures; simplified desig…
We present a multi-conjugate adaptive optics (MCAO) system simulator bench, HeNOS (Herzberg NFIRAOS Optical Simulator). HeNOS is developed to validate the performance of the MCAO system for the Thirty Meter Telescope, as well as to demonstrate techniques critical for future AO developments. In this paper, we focus on describing the derivations of parameters that scale the 30-m telescope AO system down to a bench experiment and explain how these parameters are practically implemented on an optical bench. While referring other papers for details of AO technique developments using HeNOS, we intro…
As part of the conceptual and preliminary design processes of the Thirty Meter Telescope (TMT), the TMT site testing team has spent the last five years measuring the atmospheric properties of five candidate mountains in North and South America with an unprecedented array of instrumentation. The site testing period was preceded by several years of analyses selecting the five candidates, Cerros Tolar, Armazones and Tolonchar in northern Chile; San Pedro Martir in Baja California, Mexico and the 13 North (13N) site on Mauna Kea, Hawaii. Site testing was concluded by the selection of two remaining…
The results on the vertical distribution of optical turbulence above the five mountains which were investigated by the site testing for the Thirty Meter Telescope (TMT) are reported. On San Pedro Martir in Mexico, the 13 North site on Mauna Kea and three mountains in northern Chile Cerro Tolar, Cerro Armazones and Cerro Tolonchar, MASS-DIMM turbulence profilers have been operated over at least two years. Acoustic turbulence profilers - SODARs - were also operated at these sites. The obtained turbulence profiles indicate that at all sites the lowest 200m are the main source of the total seeing …
We report on the expected astrometric performance of the Thirty Meter Telescope's InfraRed Imaging Spectrometer (IRIS) as determined using simulated images of the Galactic center. This region of the Galaxy harbors a supermassive black hole and a dense nuclear stellar cluster, thus providing an ideal laboratory for testing crowded-field astrometry with the IRIS imager. Understanding the sources of astrometric error is also important for making precision measurements of the short-period stars orbiting the supermassive black hole in order to probe the curvature of space-time as predicted by Gener…
Maunakea, the proposed site of the Thirty Meter Telescope (TMT), is a lightning-rod topic for Native Hawaiians, Hawaii residents, and the international astronomy community. In this paper we, Native Hawaiian natural scientists and allies, identify historical decisions that impact current circumstances on Maunakea and provide approaches to acknowledging their presence. Our aim is to provide an Indigenous viewpoint centered in Native Hawaiian perspectives on the impacts of the TMT project on the Hawaiian community. We summarize the current Maunakea context from the perspective of the authors who …
The proposed US Extremely Large Telescope (ELT) Program would secure national open access to at least 25% of the observing time on the Thirty Meter Telescope in the north and the Giant Magellan Telescope in the south. ELTs would advance solar system science via exceptional angular resolution, sensitivity, and advanced instrumentation. ELT contributions would include the study of interstellar objects, giant planet systems and ocean worlds, the formation of the solar system traced through small objects in the asteroid and Kuiper belts, and the active support of planetary missions. We recommend t…
HISPEC (High-resolution Infrared Spectrograph for Exoplanet Characterization) is a proposed diffraction-limited spectrograph for the W.M. Keck Observatory, and a pathfinder for the MODHIS facility project (Multi-Object Diffraction-limited High-resolution Infrared Spectrograph) on the Thirty Meter Telescope. HISPEC/MODHIS builds on diffraction-limited spectrograph designs which rely on adaptively corrected single-mode fiber feeds. Seeing-limited high-resolution spectrographs, by virtue of the conservation of beam etendue, grow in volume following a D^3 power law (D is the telescope diameter), a…
A review of modernization and growth of ground based optical and near-infrared astrophysical observational facilities in the globe attributed to the recent technological developments in optomechanical, electronics and computer science areas is presented. Hubble Space Telescope (HST) and speckle and adaptive ground based imaging have obtained images better than 0.1 arc sec angular resolution bringing the celestial objects closer to us at least by a factor of 10 during the last two decades. From the light gathering point of view, building of large size (more than 5 meter aperture) ground based o…
Observatory end-to-end science operations is the overall process starting with a scientific question, represented by a proposal requesting observing time, and ending with the analysis of observation data addressing that question, and including all the intermediate steps needed to plan, schedule, obtain, and process these observations. Increasingly complex observing facilities demand a highly efficient science operations approach and at the same time be user friendly to the astronomical user community and enable the highest possible scientific return. Therefore, this process is supported by a c…
The optical turbulence conditions as measured between 2004 until end of 2008 above Cerro Tololo, their seasonal as well as nocturnal behavior are presented. A comparison with the MASS-DIMM system of the Thirty Meter Telescope site testing was conducted and identifies an artificially increased seeing component in the data collected by the CTIO DIMM system under northerly winds. Evidence is shown that this increased turbulence is caused by the telescope dome. A correction for this effect is attempted and applied to the CTIO DIMM data. The MASS data of this comparison campaign allow to set constr…
The InfraRed Imaging Spectrograph (IRIS) is a first-light instrument being designed for the Thirty Meter Telescope (TMT). IRIS is a combination of an imager that will cover a 16.4" field of view at the diffraction limit of TMT (4 mas sampling), and an integral field unit spectrograph that will sample objects at 4-50 mas scales. IRIS will open up new areas of observational parameter space, allowing major progress in diverse fields of astronomy. We present the science case and resulting requirements for the performance of IRIS. Ultimately, the spectrograph will enable very well-resolved and sens…
Powerful Laser Guide Star (LGS) systems are standard for the next-generation of extremely large telescopes. However, modern earth-based astronomy has gone through a process of concentration on few sites with exceptional sky quality, resulting in those becoming more and more crowded. The future LGS systems encounter hence an environment of surrounding astronomical installations, some of which observing with large fields-of-view. We derive formulae to calculate the impact of LGS light on the camera of a neighbouring telescope and the probabilities for a laser crossing the camera field-of-view to…
After 16 years of on-sky operation, Subaru Telescope's facility adaptive optics AO188 is getting several major upgrades to become the extreme-AO AO3000 (3000 actuators in the pupil compared to 188 previously). AO3000 will provide high-Strehl images for several instruments from visible to mid-infrared, notably the Infrared Camera and Spectrograph (IRCS), and the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO). For this upgrade, the original 188-element deformable mirror (DM) will be replaced with ALPAO's $64\times64$ DM. The visible wavefront sensor will also be upgraded at a later date, …
To ensure progress in astronomy over the coming decades, the key questions are "what facilities will we build, and when?" Toward this end, the Association of Universities for Research in Astronomy (AURA) recently commissioned a study on future space-based options for UV and optical astronomy. The resulting study - "From Cosmic Birth to Living Earths" - concluded that a space telescope equipped with a 12-meter class primary mirror would make fundamental advances across virtually all of astrophysics, including finding and characterizing the atmospheres of dozens of Earth-like planets. This ambit…
The Canada France Hawaii Telescope Corporation (CFHT) plans to repurpose its observatory on the summit of Maunakea and operate a new wide field spectroscopic survey telescope, the Maunakea Spectroscopic Explorer (MSE). MSE will upgrade the observatory with a larger 11.25m aperture telescope and equip it with dedicated instrumentation to capitalize on the site, which has some of the best seeing in the northern hemisphere, and offer its user community the ability to do transformative science. The knowledge and experience of the current CFHT staff will contribute greatly to the engineering of thi…
The proposed next generation Event Horizon Telescope (ngEHT) concept envisions the imaging of various astronomical sources on scales of microarcseconds in unprecedented detail with at least two orders of magnitude improvement in the image dynamic ranges by extending the Event Horizon Telescope (EHT). A key technical component of ngEHT is the utilization of large aperture telescopes to anchor the entire array, allowing the connection of less sensitive stations through highly sensitive fringe detections to form a dense network across the planet. Here, we introduce two projects for planned next g…
Many of the transformative processes in the Universe have taken place in regions obscured by dust, and are best studied with far-IR spectroscopy. We present the Cryogenic-Aperture Large Infrared-Submillimeter Telescope Observatory (CALISTO), a 5-meter class, space-borne telescope actively cooled to 4 K, emphasizing moderate-resolution spectroscopy in the crucial 35 to 600 micron band. CALISTO will enable NASA and the world to study the rise of heavy elements in the Universe's first billion years, chart star formation and black hole growth in dust-obscured galaxies through cosmic time, and cond…
Lens time delays are a powerful probe of cosmology, provided that the gravitational potential of the main deflector can be modeled with sufficient precision. Recent work has shown that this can be achieved by detailed modeling of the host galaxies of lensed quasars, which appear as "Einstein Rings" in high resolution images. We carry out a systematic exploration of the high resolution imaging required to exploit the thousands of lensed quasars that will be discovered by current and upcoming surveys with the next decade. Specifically, we simulate realistic lens systems as imaged by the Hubble S…
Decades long monitoring of millisecond pulsars, which exhibit highly stable rotational periods, in pulsar timing array experiments is on the threshold of discovering nanohertz stochastic gravitational wave background. This paper describes the Indian Pulsar timing array (InPTA) experiment, which employs the upgraded Giant Metrewave Radio Telescope (uGMRT) for timing an ensemble of millisecond pulsars for this purpose. We highlight InPTA's observation strategies and analysis methods, which are relevant for a future PTA experiment with the more sensitive Square Kilometer Array (SKA) telescope. We…
