TMT Observatory

MAVIS (the MCAO-Assisted Visible Imager and Spectrograph), planned for the VLT Adaptive Optics Facility, represents an innovative step in Multi-Conjugate Adaptive Optics (MCAO) systems, particularly in its operation at visible wavelengths and anticipated contributions to the field of astronomical astrometry. Recognizing the crucial role of high-precision astrometry in realizing science goals such as studying the dynamics of dense starfields, this study focuses on the challenges of advancing astrometry with MAVIS to its limits, as well as paving the way for further enhancement by incorporating telemetry data as part of the astrometric analysis. We employ MAVISIM, Superstar, and DAOPHOT to simulate both MAVIS imaging performance and provide a pathway to incorporate telemetry data for precise astrometry with MAVIS. Photometry analyses are conducted using the Superstar and DAOPHOT platforms, integrated into a specifically designed pipeline for astrometric analysis in MCAO settings. Combining these platforms, our research aims to elucidate the impact of utilizing telemetry data on improving astrometric precision, potentially establishing new methods for ground-based AO-assisted astrometric analysis. This endeavor not only sheds light on the capabilities of MAVIS but also paves the way for advancing astrometry in the era of next-generation MCAO-enabled giant telescopes.

Adaptive optics (AO) systems are crucial for high-resolution astronomical observations by compensating for atmospheric turbulence. While laser guide stars (LGS) address high-order wavefront aberrations, natural guide stars (NGS) remain vital for low-order wavefront sensing (LOWFS). Conventional NGS-based methods like Shack-Hartmann sensors have limitations in field of view, sensitivity, and complexity. Focal plane wavefront sensing (FPWFS) offers advantages, including a wider field of view and enhanced signal-to-noise ratio, but accurately estimating low-order modes from distorted point spread functions (PSFs) remains challenging. We propose an AI-powered FPWFS method specifically for low-order mode estimation in infrared wavelengths. Our approach is trained on simulated data and validated on on-telescope data collected from the Keck I adaptive optic (K1AO) bench calibration source in K-band. By leveraging the enhanced signal-to-noise ratio in the infrared and the power of AI, our method overcomes the limitations of traditional LOWFS techniques. This study demonstrates the effectiveness of AI-based FPWFS for low-order wavefront sensing, paving the way for more compact, efficient, and high-performing AO systems for astronomical observations.

In October 2023, TMT International Observatory contracted AMOS to develop the Secondary Mirror Support System and Positioner (M2SSP). The M2SSP was identified by TIO as a critical sub-system for which early design would substantially reduce technical, schedule and cost risks to the overall TMT project development plan. In this paper, we present the preliminary design of the M2SSP elaborated by AMOS to comply with the demanding performance requirements imposed by the operational cases and the environment of TMT. The M2SSP is composed of a semi-active mirror support assembly (M2CA) and a positioner (M2POS) that consists of a hexapod with tracking capabilities.

The Infrared Imaging Spectrograph (IRIS) is a diffraction-limited instrument designed for the Thirty Meter Telescope (TMT) through an international collaboration. IRIS works in tandem with the Narrow-Field InfraRed Adaptive Optics System (NFIRAOS) and covers a near-infrared spectral range of 0.84 to 2.4 microns. IRIS and NFIRAOS will be the instruments used to demonstrate first light at TMT. IRIS incorporates a wide-field Imager with a fixed plate scale of 4 milliarcseconds (mas), and an Integral Field Spectrograph (IFS) offering four plate scales that range from 4 mas to 50 mas. In 2021, the major subsystems of IRIS went through final design reviews. This paper provides an update on IRIS design and outlines the plan for its fabrication, integration, and delivery to TMT for first light.

ABSTRACT JWST/NIRCam obtained high angular resolution (0.05–0.1 arcsec), deep near-infrared 1–5 $\mu$m imaging of Supernova (SN) 1987A taken 35 yr after the explosion. In the NIRCam images, we identify: (1) faint H2 crescents, which are emissions located between the ejecta and the equatorial ring, (2) a bar, which is a substructure of the ejecta, and (3) the bright 3–5 $\mu$m continuum emission exterior to the equatorial ring. The emission of the remnant in the NIRCam 1–2.3 $\mu$m images is mostly due to line emission, which is mostly emitted in the ejecta and in the hotspots within the equatorial ring. In contrast, the NIRCam 3–5 $\mu$m images are dominated by continuum emission. In the ejecta, the continuum is due to dust, obscuring the centre of the ejecta. In contrast, in the ring and exterior to the ring, synchrotron emission contributes a substantial fraction to the continuum. Dust emission contributes to the continuum at outer spots and diffuse emission exterior to the ring, but little within the ring. This shows that dust cooling and destruction time-scales are shorter than the synchrotron cooling time-scale, and the time-scale of hydrogen recombination in the ring is even longer than the synchrotron cooling time-scale. With the advent of high sensitivity and high angular resolution images provided by JWST/NIRCam, our observations of SN 1987A demonstrate that NIRCam opens up a window to study particle-acceleration and shock physics in unprecedented details, probed by near-infrared synchrotron emission, building a precise picture of how an SN evolves.

Supernova (SN) 1987A offers a unique opportunity to study how a spatially resolved SN evolves into a young SN remnant. We present and analyze Hubble Space Telescope (HST) imaging observations of SN 1987A obtained in 2022 and compare them with HST observations from 2009 to 2021. These observations allow us to follow the evolution of the equatorial ring (ER), the rapidly expanding ejecta, and emission from the center over a wide range in wavelength from 2000 to 11,000 Å. The ER has continued to fade since it reached its maximum ∼8200 days after the explosion. In contrast, the ejecta brightened until day ∼11,000 before their emission levelled off; the west side brightened more than the east side, which we attribute to the stronger X-ray emission by the ER on that side. The asymmetric ejecta expand homologously in all filters, which are dominated by various emission lines from hydrogen, calcium, and iron. From this overall similarity, we infer the ejecta are chemically well mixed on large scales. The exception is the diffuse morphology observed in the UV filters dominated by emission from the Mg ii resonance lines that get scattered before escaping. The 2022 observations do not show any sign of the compact object that was inferred from highly ionized emission near the remnant’s center observed with JWST. We determine an upper limit on the flux from a compact central source in the [O iii] HST image. The nondetection of this line indicates that the S and Ar lines observed with JWST originate from the O free inner Si–S–Ar-rich zone and/or that the observed [O iii] flux is strongly affected by dust scattering.

ABSTRACT We present results of a Hubble Space Telescope (HST) UBVI-band study of star clusters in tidal tails, using new WFC3 and ACS imaging to complement existing WFPC2 data. We survey 12 tidal tails across seven merging systems, deriving ages and masses for 425 star cluster candidates (SCCs). The stacked mass distribution across all systems follows a power law of the form dN/dM ∝ Mβ, with β = −2.02 ± 0.15, consistent with what is seen in other star-forming environments. GALEX and Swift UV imaging provide star formation rates (SFRs) for our tidal tails, which when compared with ages and masses of our SCCs, allows for a determination of the cluster formation efficiency (CFE). We find the CFE increases with increasing SFR surface density, matching the theoretical model. We confirm this fit down at SFR densities lower than previously measured (log ΣSFR (M⊙ yr−1 kpc−2) ≈ −4.2), as related to the CFE. We determine the half-light radii for a refined sample of 57 SCCs with our HST WFC3 and ACS imaging, and calculate their dynamical age, finding the majority of them to be gravitationally bound. We also provide evidence of only low-mass (<104 M⊙) cluster formation in our nearest galaxy, NGC 1487, consistent with the theory that this system is a dwarf merger.

The design and development of the TMT Software System is a complex, multi-year project that includes management, reviews, design work, and construction of software with a multi-organization team that spans three continents. The initial conceptual design was completed in 2014 and following multiple reviews, the construction phase began in 2017 with our India-based development partners. With completion of the TMT Common Software in 2019, construction development moved to the first phase of the Executive Software system, which was completed in late 2021. This paper describes the current state of the TMT Software System summarizing what has been accomplished to date and the next steps in design and development. Within the last year, TMT has become part of the larger USELT project, and this paper describes how this has influenced the software design and future development plans.

The US Extremely Large Telescope Program (US-ELTP) will enable all US astronomers to carry out transformational research that takes full advantage of the diverse capabilities of both the Giant Magellan Telescope (GMT) and the Thirty Meter Telescope (TMT) as parts of a two-hemisphere system. The US-ELT Program Platform (UPP), the NSF’s NOIRLab software suite, will provide the majority of the services to support the entire Scientific Data Life Cycle (SDLC) from submission of proposals to data reduction, analysis, and publication. We present an overview of the high-level vision for the Data Reduction and Analysis Workspace (DRAW), as well as a description of its main functionalities, that will be part of the UPP. DRAW will provide data reduction services, data analysis tools, access to databases, and other services to the scientific community, including researchers at under-resourced institutions. DRAW’s purpose is to facilitate and support the creation, archival, and curation of GMT/TMT science data products and ensure their legacy value.