We discuss the predicted performance of the HARMONI spectrograph and the ELT in the context of two specific science cases: resolved stellar populations of Local Volume galaxies and Galactic archaeology in dense environments. We have produced and analysed a set of simulated data-cubes using the HSIM software, mimicking observations across the giant elliptical galaxy Centaurus A and in the nuclear bulge of the Milky Way. We use our results to demonstrate the instruments capabilities to perform stellar absorption line spectroscopy in a large number of stars which will allow us to study the detailed kinematics and stellar population characteristics of these high density regions
Extending the simulations of intermediate-mass black hole mass measurements to Virgo Cluster using ELT/HARMONI high resolution integral-field stellar kinematics
Simulating intermediate black hole mass measurements for a sample of galaxies with nuclear star clusters using ELT/HARMONI high spatial resolution integral-field stellar kinematics
Gravitational lensing is an important prediction of general relativity, providing both its test and a tool to detect faint but amplified sources and to measure masses of lenses. For some applications (e.g. testing the theory), a point source lensed by a point-like lens would be more advantageous. However, until now only one gravitationally lensed star has been resolved. The future telescopes will resolve very small lensing signatures for stars orbiting the supermassive black hole (SMBH) in the center of the Milky Way. The lensing signatures should however be easier to detect for background sta…
Extending the Frontier of Spatially-Resolved Supermassive Black Hole Mass Measurements to at $1\lesssim z\lesssim2$: Simulations with ELT/MICADO High-Resolution Mass Models and HARMONI Integral-Field Stellar Kinematics
University of Michigan（密歇根大学）；University of Oxford（牛津大学）；University of Science, Vietnam National University in Ho Chi Minh City（越南国立大学胡志明市自然科学大学）；Instituto de Física Fundamental, CSIC（西班牙国家科学研究委员会基础物理研究所）
Simulating supermassive black hole mass measurements for a sample of ultra massive galaxies using ELT/HARMONI high spatial resolution integral-field stellar kinematics
Probing the Variation of the Inner Surface-Brightness Profile of Nuclear Star Clusters on the Intermediate-Mass Black Hole Mass Measurements Using Mock Observations of ELT/MICADO and HARMONI
International University, Vietnam National University in Ho Chi Minh City（越南国立大学胡志明市国际大学）；University of Michigan（密歇根大学）；University of Science, Vietnam National University in Ho Chi Minh City（越南国立大学胡志明市科学大学）
Population III (Pop. III) stars, as of yet, have not been detected, however as we move into the era of extremely large telescopes this is likely to change. One likely tracer for Pop. III stars is the HeII$\lambda1640$ emission line, which will be detectable by the HARMONI spectrograph on the European Extremely Large Telescope (ELT) over a broad range of redshifts ($2\leq z\leq14$). By post-processing galaxies from the cosmological, AMR-hydrodynamical simulation NewHorizon with theoretical spectral energy distributions (SED) for Pop. III stars and radiative transfer (i.e. the Yggdrasil Models a…
HARMONI@ELT: instrument design, performance, and science capabilities
LAM, Aix Marseille Univ., CNRS, CNES（LAM，艾克斯-马赛大学，法国国家科学研究中心，法国国家空间研究中心）；Univ. of Edinburgh（爱丁堡大学）；UK Astronomy Technology Centre, STFC（英国天体技术中心，英国科学与技术设施委员会）；Univ. of Durham（杜伦大学）；Instituto de Astrofísica de Canarias（加那利群岛天体物理研究所）；University of Oxford（牛津大学）；Centre de Recherche en Astrophysique de Lyon（里昂天体物理研究中心）；Centro de Astrobiología (CAB), CSIC-INTA（天体生物学中心（CAB），西班牙国家技术研究与发展总署/西班牙高等科学研究理事会）；University of Michigan（密歇根大学）；Institut de Planétologie et d’Astrophysique de Grenoble（格勒诺布尔行星学与天体物理学研究所）
Constraining the Galactic Center Dark Cluster with ELT/MICADO Observations
Canadian Institute for Theoretical Astrophysics, University of Toronto（多伦多大学理论天体物理研究所）；Max Planck Institute for Radioastronomy（马克斯·普朗克射电天文研究所）；Department of Theoretical Physics and Astrophysics, Masaryk University（马萨里克大学理论与天体物理学系）
Aims. In this work we aim to estimate the lowest stellar mass that MICADO at the ELT will be able to reliably detect given a stellar density and distance. We also show that instrumental effects that will play a critical role, and report the number of young clusters that will be accessible for IMF studies in the local Universe with the ELT. Methods. We used SimCADO, the instrument simulator package for the MICADO camera, to generate observations of 56 dense stellar regions with densities similar to the cores of young stellar clusters. We placed the cluster fields at distances between 8 kpc and …
(ABRIDGED) Globular clusters trace the formation and evolution of the Milky Way and surrounding galaxies, and outline their chemical enrichment history. To accomplish these tasks it is important to have large samples of clusters with homogeneous data and analysis to derive kinematics, chemical abundances, ages and locations. We obtain homogeneous metallicities and alpha-element enhancement for over 800 red giant stars in 51 Galactic bulge, disc, and halo globular clusters that are among the most distant and/or highly reddened in the Galaxy's globular cluster system. We observed R ~ 2000 spectr…
We present simulated observations of gas kinematics in galaxies formed in 10 pc resolution cosmological simulations with the hydrodynamical + N-body code RAMSES, using the new RAMSES2HSIM pipeline with the simulated observing pipeline (HSIM) for the ELT HARMONI IFU spectrograph. We post-process the galaxy's gas kinematics and Hα line emission for each simulation cell, and integrate the emission to produce an extinction-corrected input cube. We then simulate observations of the input cube with HARMONI, for a range of exposure times, spatial sampling, and spectral resolution. We analyze the mock…
Kinematic Signatures in the Stellar Halo from Cosmological Encounters between the Milky Way and its Clouds
University of Pennsylvania（宾夕法尼亚大学）；Institute for Astronomy, University of Hawai‘i（夏威夷大学天体物理研究所）；University of Washington（华盛顿大学）；Boston University（波士顿大学）；Carnegie Observatories（卡内基观测站）；California Institute of Technology（加州理工学院）
Context. The formation and evolution of galaxies appear linked to the growth of supermassive black holes, as evidenced by empirical scaling relations in nearby galaxies. Understanding this co-evolution over cosmic time requires the revelation of the dynamical state of galaxies and the measurement of the mass of their central black holes (MBH) at a range of cosmic distances. Bright active galactic nuclei (AGNs) are ideal for this purpose. Aims. The High Angular Resolution Monolithic Optical and Near-infrared Integral field spectrograph (HARMONI), the first light integral-field spectrograph for …
Probing IMF Variations in High-Redshift Early-Type Galaxies with SHARP
INAF-Osservatorio Astronomico di Capodimonte（意大利国家天体物理研究所卡波迪蒙特天文台）；INAF-Osservatorio Astronomico di Trieste（意大利国家天体物理研究所的里雅斯特天文台）；IFPU - Institute for Fundamental Physics of the Universe（宇宙基础物理研究所）；INAF-Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；INAF–Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF-Milano)（意大利国家天体物理研究所空间天体物理与宇宙学研究所（米兰））；INAF-Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿切特里天文台）；Instituto de Astrofísica de Canarias (IAC)（加那利群岛天体物理研究所）
We model the response of spherical, non-rotating Milky Way (MW) dark matter and stellar halos to the Large Magellanic Cloud (LMC) using the matrix method of linear response theory. Our computations reproduce the main features of the dark halo response from simulations. We show that these features can be well separated by a harmonic decomposition: the large scale over/underdensity in the halo (associated with its reflex motion) corresponds to the $\ell=1$ terms, and the local overdensity to the $\ell\geq2$ multipoles. Moreover, the dark halo response is largely dominated by the first order 'for…
Increasingly powerful and multiplexed spectroscopic facilities promise detailed chemical abundance patterns for millions of resolved stars in galaxies beyond the Milky Way (MW). Here, we employ the Cramér-Rao Lower Bound (CRLB) to forecast the precision to which stellar abundances for metal-poor, low-mass stars outside the MW can be measured for 41 current (e.g., Keck, MMT, VLT, DESI) and planned (e.g., MSE, JWST, ELTs) spectrograph configurations. We show that moderate resolution ($R\lesssim5000$) spectroscopy at blue-optical wavelengths ($λ\lesssim4500$ Å) (i) enables the recovery of 2-4 tim…
The nature, size and orientation of the dominant structural components in the Milky Way's inner ~4 kpc - specifically the bulge and bar - have been the subject of conflicting interpretations in the literature. We present a different approach to inferring the properties of the long bar which extends beyond the inner bulge, via the information encoded in the Galaxy's X/peanut (X/P)-shaped structure. We perform a quantitative analysis of the X/P feature seen in WISE wide-field imaging at 3.4 $μ$m and 4.6 $μ$m. We measure the deviations of the isophotes from pure ellipses, and quantify the X/P str…
We present a study into the capabilities of integrated and spatially resolved integral field spectroscopy of galaxies at z=2-4 with the future HARMONI spectrograph for the European Extremely Large Telescope (E-ELT) using the simulation pipeline, HSIM. We focus particularly on the instrument's capabilities in stellar absorption line integral field spectroscopy, which will allow us to study the stellar kinematics and stellar population characteristics. Such measurements for star-forming and passive galaxies around the peak star formation era will provide a critical insight into the star formatio…
The Milky Way's dark matter halo appears to be lopsided
银河系外围区域（距中心约10 kpc）的氢原子盘可以提供有关暗物质晕结构的有价值的信息。最近来自全天21厘米线LAB测量的外HI盘的3-D厚度图为我们提供了一个独特的机会来详细研究银河系暗物质晕的结构。这项新调查的一个显著特点是原子氢气体厚度图的南北不对称性。假设在银河系总势能下垂直流体静力平衡，我们导出了HI气体的模型厚度图。我们指出，简单的轴对称晕模型，如软化的等温晕（在Vc ~ 220 km/s处产生平坦的旋转曲线）或任何密度下降快于等温晕的晕，都不能解释所观测到的气体厚度的径向变化。我们还表明，这种轴对称晕随着不同的HI速度分散在两半，不能解释所观察到的厚度图中的不对称性。其中的非轴对称模型，它表明，一个纯粹的不平衡（m=1，第一谐波）暗物质晕合理HI速度色散未能解释南北不对称令人满意。然而，我们发现，通过在一个完全不平衡的晕上叠加一个二次谐波（m=2），例如我们的最佳拟合和更可接受的模型A（参数ε h ^{1}=0.2，ε h ^{2}=0.18，σ HI =8.5 km/s），可以提供一个很好的拟合，并自然地再现南北不对称性。新出现的不对称暗物质晕的图像得到了宇宙学N体模拟中形成的ΛCDM晕的支持。
We investigate the ability of basis function expansions to reproduce the evolution of a Milky Way-like dark matter halo, extracted from a cosmological zoom-in simulation. For each snapshot, the density of the halo is reduced to a basis function expansion, with interpolation used to recreate the evolution between snapshots. The angular variation of the halo density is described by spherical harmonics, and the radial variation either by biorthonormal basis functions adapted to handle truncated haloes or by splines. High fidelity orbit reconstructions are attainable using either method with simil…
Over the past decade, research in resolved stellar populations has made great strides in exploring the nature of dark matter, in unraveling the star formation, chemical enrichment, and dynamical histories of the Milky Way and nearby galaxies, and in probing fundamental physics from general relativity to the structure of stars. Large surveys have been particularly important to the biggest of these discoveries. In the coming decade, current and planned surveys will push these research areas still further through a large variety of discovery spaces, giving us unprecedented views into the low surf…
