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we use hst/stis optical spectroscopy of 10 m dwarfs in five closely separated binary systems to test models of m-dwarf structure and evolution. individual dynamical masses ranging from 0.083 to 0.405 m⊙ for all stars are known from previous work. we first derive temperature, radius, luminosity, surface gravity, and met... | the solar neighborhood. xlvii. comparing m-dwarf models with hubble space telescope dynamical masses and spectroscopy |
we present the serendipitous discovery of eclipse-like events around the massive white dwarf sdss j152934.98+292801.9 (hereafter j1529+2928). we selected j1529+2928 for time-series photometry based on its spectroscopic temperature and surface gravity, which place it near the zz ceti instability strip. instead of pulsat... | a dark spot on a massive white dwarf |
the transiting exoplanet survey satellite (tess) mission detected a companion orbiting tic 71268730, categorized it as a planet candidate, and designated the system toi-5375. our follow-up analysis using radial-velocity data from the habitable-zone planet finder, photometric data from red buttes observatory, and speckl... | toi-5375 b: a very low mass star at the hydrogen-burning limit orbiting an early m-type star |
we present reprocessed flux-calibrated spectra of 406 stars from the uves-pop stellar library in the wavelength range 320-1025 nm, which can be used for stellar population synthesis. the spectra are provided in the two versions having spectral resolving power r = 20,000 and r = 80,000. raw spectra from the eso data arc... | new generation stellar spectral libraries in the optical and near-infrared. i. the recalibrated uves-pop library for stellar population synthesis |
characterization of atmospheric optical turbulence is crucial for the design and operation of modern ground-based optical telescopes. in particular, the effective application of adaptive optics correction on large and extremely large telescopes relies on a detailed knowledge of the prevailing atmospheric conditions, in... | shimm: a versatile seeing monitor for astronomy |
context. ngc 3532 is an extremely rich open cluster embedded in the galactic disc, hitherto lacking a comprehensive, documented membership list.aims: we provide membership probabilities from new radial velocity observations of solar-type and low-mass stars in ngc 3532, in part as a prelude to a subsequent study of stel... | spectroscopic membership for the populous 300 myr-old open cluster ngc 3532 |
since its emergence two decades ago, astrophotonics has found broad application in scientific instruments at many institutions worldwide. the case for astrophotonics becomes more compelling as telescopes push for ao-assisted, diffraction-limited performance, a mode of observing that is central to the next-generation of... | astrophotonics: molding the flow of light in astronomical instruments |
the summit of the antarctic plateau, dome a, is proving to be an excellent site for optical, near-infrared, and terahertz astronomical observations. gattini is a wide-field camera installed on the plato instrument module as part of the chinese-led traverse to dome a in 2009 january. we present here the measurements of ... | optical sky brightness and transparency during the winter season at dome a antarctica from the gattini-all-sky camera |
we report the results from a spectrophotometric study sampling the ≳ 300 candidate supernova remnants (snrs) in m83 identified through optical imaging with magellan/imacs and hubble space telescope/wfc3. of the 118 candidates identified based on a high [s ii] λλ 6716, 6731 to hα emission ratio, 117 show spectroscopic s... | a spectroscopic study of the rich supernova remnant population in m83 |
observations of the sun provide unique insights into its structure, evolution, and activity, with significant implications for space weather forecasting and solar energy technologies. ground-based telescopes offer cost-effective and flexible solutions for high-resolution solar observations, but image quality can be aff... | comparative analysis of image-shift measurement algorithms for solar shack-hartmann wavefront sensors |
context. detailed chemical abundances of galactic stars are needed in order to improve our knowledge of the formation and evolution of our galaxy, the milky way.aims: we took advantage of the giano archive spectra to select a sample of galactic disc stars in order to derive their chemical inventory and to compare the a... | systematic investigation of chemical abundances derived using ir spectra obtained with giano |
context. the number of satellites launched into earth's orbit has almost tripled in the last three years (to over 4000) due to the increasing commercialisation of space. multiple satellite constellations, consisting of over 400 000 individual satellites, have either been partially launched or are proposed for launch in... | impact of satellite trails on h.e.s.s. astronomical observations |
where dust and gas are uniformly mixed, atomic hydrogen can be traced through the detection of far-infrared (fir) or uv emission of dust. we considered, for the origin of discrepancies observed between various direct and indirect tracers of gas outside the galactic plane, possible corrections to the zero levels of the ... | evidence for large-scale excesses associated with low h i column densities in the sky. i. dust excess |
we have observed the didymos-dimorphos binary system with the muse integral field unit spectrograph mounted at the very large telescope before and after dart impact and captured the ensuing ejecta cone, debris cloud, and tails at subarcsecond resolutions. we targeted the didymos system over 11 nights from 2022 septembe... | vlt/muse characterization of dimorphos ejecta from the dart impact |
the legacy survey of space and time (lsst) is slated to commence in 2025 at the vera rubin observatory. one of the crucial parts of preparing the survey is the choice of observing cadence in an effort to optimize auxiliary science goals while maintaining the core project requirements. here we look at the impact of prop... | the lsst cadence impact on non-time-critical eclipsing binary science |
context. the hubble diagram of type-ia supernovae (sne-ia) provides cosmological constraints on the nature of dark energy with an accuracy limited by the flux calibration of currently available spectrophotometric standards. this motivates new developments to improve the link between existing astrophysical flux standard... | stardice. i. sensor calibration bench and absolute photometric calibration of a sony imx411 sensor |
ai and deep learning techniques are playing an increasing role in astronomy to deal with the data avalanche. here we describe an application for finding resolved planetary nebulae (pne) in crowded, wide-field, narrow-band hα survey imagery in the galactic plane, to test and facilitate more objective, reproducible, effi... | ai techniques for uncovering resolved planetary nebula candidates from wide-field vphas+ survey data |
we present hubble space telescope photometry in the optical (f475x) and near-infrared (f110w) bands of the globular cluster (gc) systems of the inner halos of a sample of 15 massive elliptical galaxies. the targets are selected from the volume-limited massive survey, and chosen to sample a range of environments from sp... | comparing globular cluster system properties with host galaxy environment |
we report the discovery of a faint optical tidal disruption event (tde) in the nearby star-forming galaxy ngc 3799. identification of the tde is based on its position at the galaxy nucleus, a light curve declining as t -5/3, a blue continuum with an almost constant blackbody temperature of ~12,000 k, broad (≈15,000 km ... | at 2023clx: the faintest and closest optical tidal disruption event discovered in nearby star-forming galaxy ngc 3799 |
the large synoptic survey telescope (lsst) will be an 8.4m optical survey telescope sited in chile and capable of imaging the entire sky twice a week. the data rate of approximately 15tb per night and the requirements to both issue alerts on transient sources within 60 seconds of observing and create annual data releas... | investigating interoperability of the lsst data management software stack with astropy |
there is considerable uncertainty as to the amount of carbon incorporated in interstellar dust. the aliphatic component of the carbonaceous dust is of particular interest because it produces a significant 3.4 μm absorption feature when viewed against a background radiation source. the optical depth of the 3.4 μm absorp... | aliphatic hydrocarbon content of interstellar dust |
neid is a high-resolution red-optical precision radial velocity (rv) spectrograph recently commissioned at the wiyn 3.5 m telescope at kitt peak national observatory, arizona, usa. neid has an extremely stable environmental control system, and spans a wavelength range of 380-930 nm with two observing modes: a high reso... | stable fiber-illumination for extremely precise radial velocities with neid |
a comprehensive design of a folded-architecture arrayed-waveguide-grating (awg)-device, targeted at applications as integrated photonic spectrographs (ips) in near-infrared astronomy, is presented. the awg structure is designed for the astronomical h-band (1500 nm–1800 nm) with a theoretical maximum resolving power r =... | high-resolution arrayed-waveguide-gratings in astronomy: design and fabrication challenges |
optical microscopy is an indispensable tool in biomedical sciences, but its reach in deep tissues is limited due to aberrations and scattering. this problem can be overcome by wavefront-shaping techniques, albeit at limited fields of view (fovs). inspired by astronomical imaging, conjugate wavefront shaping can lead to... | dynamic conjugate f-sharp microscopy |
spectroscopy of molecules in the mid-infrared (mir) region has important applications in various fields, such as astronomical observation, environmental detection, and fundamental physics. however, compared to that in the near-infrared, precision spectroscopy in the mir is often limited by the light source and has not ... | cavity ring-down spectroscopy based on a comb-locked optical parametric oscillator source |
context. one of the key challenges facing direct exoplanet imaging is the continuous maintenance of the region of high contrast within which light from the exoplanet can be detected above the stellar noise. in high-contrast imaging systems, the dominant source of aberrations is the residual wavefront error that arises ... | spatial linear dark field control on subaru/scexao. maintaining high contrast with a vapp coronagraph |
effects derived from the simultaneous application of passive, uniform saturating magnetic field and tensile stress during long-time annealing utilizing a unique and simple processing tool, the multidriver furnace, are reported. in particular, the evolution of the crystalline structure and the magnetic domain configurat... | creating, probing and confirming tetragonality in bulk feni alloys |
the ablation of cosmic dust entering the atmosphere causes the formation of an atomic potassium (k) layer in the mesopause region. it can be studied via resonance fluorescence from the k(d1) line at 769.9 nm, stimulated by sunlight or a laser. in addition, the faint emission from a chemiluminescent cycle involving ozon... | observations and modeling of potassium emission in the terrestrial nightglow |
we present the result of a survey of sunspots and auroras in qíngshǐgǎo (清史稿), a draft chronicle of qíng dynasty, for the period of 1559-1912 ce. this is a sequel to a series of works surveying historical sunspot and aurora records, and providing online data to the scientific community regarding the attained results. i... | aurora candidates from the chronicle of qíng dynasty in several degrees of relevance |
estimation of aerosol radiative forcing (arf) was performed using a radiative transfer model (rstar6b) along with physical and optical parameters of aerosols obtained from sky radiometer observation over indian astronomical observatory (iao), hanle, ladakh, during 2008-2010 from dust, anthropogenic, and aged background... | estimation of aerosol radiative forcing over an aged-background aerosol feature during advection and non-advection events using a ground-based data obtained from a prede skyradiometer observation |
optical observations are one of the most important sources of data for meteor science. visual observation was the only method used for centuries and remains an important branch of meteor astronomy for monitoring daily shower activity. photography became an important tool in the second half of the 20th century, later fo... | meteors and meteor showers as observed by optical techniques |
bvri photometric observations of geosynchronous earth orbit (geo) objects were conducted with the 1.5 m cassini telescope located in loiano, italy. the observatory is operated by the inaf (national institute for astrophysics) astronomical observatory of bologna, italy. the ritchey-chrétien optical system is equipped wi... | bvri photometric observations and light-curve analysis of geo objects |
chemical evolution in molecular clouds in the interstellar medium is well established, with the identification of over 200 molecules and molecular ions. among the classes of interstellar organic compounds found are the aldehydes. however, laboratory work on the aldehydes has scarcely kept pace with astronomical discove... | propanal, an interstellar aldehyde - first infrared band strengths and other properties of the amorphous and crystalline forms |
context. the cherenkov telescope array (cta) represents the most advanced facility designed for cherenkov astronomy. astri sst-2m has been developed as a demonstrator for the small size telescope in the context of the upcoming cta. its main innovation consists in the optical layout which implements the schwarzschild-co... | first optical validation of a schwarzschild couder telescope: the astri sst-2m cherenkov telescope |
astronomical images from optical photometric surveys are typically contaminated with transient artifacts such as cosmic rays, satellite trails and scattered light. we have developed and tested an algorithm that removes these artifacts using a deep, artifact free, static sky coadd image built up through the median combi... | detection and removal of artifacts in astronomical images |
sweetspot is a 3 yr national optical astronomy observatory (noao) survey program to observe type ia supernovae (sne ia) in the smooth hubble flow with the wiyn high-resolution infrared camera (whirc) on the wiyn 3.5 m telescope. we present data from the first half of this survey, covering the 2011b-2013b noao semesters... | the first data release from sweetspot: 74 supernovae in 36 nights on wiyn+whirc |
the initial results of a two year simultaneous optical-radar meteor campaign are described. analysis of 105 double-station optical meteors having plane of sky intersection angles greater than 5° and trail lengths in excess of 2 km also detected by the middle atmosphere alomar radar system (maarsy) as head echoes was pe... | simultaneous optical and meteor head echo measurements using the middle atmosphere alomar radar system (maarsy): data collection and preliminary analysis |
a set of liquid crystal adaptive optics system for visible light is installed for 2-meter telescope in changchun, china. to get higher resolution images after adaptive optics, phase diversity (pd) is applied. two liquid crystal spatial light modulators were used for two polarized states of light, and they were also use... | astronomical observation by 2-meter telescope based on liquid crystal adaptive optics with phase diversity |
a galaxy-galaxy merger and the subsequent triggering of starburst activity are fundamental processes linked to the morphological transformation of galaxies and the evolution of star formation across the history of the universe. both nuclear and disk-wide starbursts are assumed to occur during the merger process. howeve... | star formation traced by optical and millimeter hydrogen recombination lines and free-free emissions in the dusty merging galaxy ngc 3256—muse/vlt and alma synergy |
we present the stellar population and ionized-gas outflow properties of ultraluminous ir galaxies (ulirgs) at z = 0.1-1.0 that are selected from the akari far-ir all-sky survey. we construct a catalog of 1077 ulirgs to examine feedback effects after major mergers. of the 1077 ulirgs, 202 are spectroscopically identifie... | tracing the coevolution path of supermassive black holes and spheroids with akari-selected ultraluminous ir galaxies at intermediate redshifts |
aims: this program originated as the north pole region extension of the established exoplanet survey using the 1.8 m telescope at bohyunsan optical astronomy observatory (boao). the aim of our paper is to find exoplanets in northern circumpolar stars with a precise radial velocity (rv) survey.methods: we selected about... | search for exoplanet around northern circumpolar stars. four planets around hd 11755, hd 12648, hd 24064, and 8 ursae minoris |
we present new calibrations of the near-infrared (near-ir) surface brightness fluctuation (sbf) distance method for the f110w ({j}110) and f160w ({h}160) bandpasses of the wide field camera 3 infrared channel (wfc3/ir) on the hubble space telescope. the calibrations are based on data for 16 early-type galaxies in the v... | measuring infrared surface brightness fluctuation distances with hst wfc3: calibration and advice |
we report the discovery and characterization of four transiting exoplanets by the hatnet survey. the planet hat-p-50b has a mass of 1.35 {m}{{j}} and radius of 1.29 {r}{{j}}, and orbits a bright (v=11.8 mag) m=1.27 {m}⊙ , r=1.70 {r}⊙star every p=3.1220 days. the planet hat-p-51b has a mass of 0.31 {m}{{j}} and radius o... | hat-p-50b, hat-p-51b, hat-p-52b, and hat-p-53b: three transiting hot jupiters and a transiting hot saturn from the hatnet survey |
we present near-infrared (nir) spectroscopic and photometric observations of the nearby type ia sn 2014j. the 17 nir spectra span epochs from +15.3 to +92.5 days after b-band maximum light, while the {{jhk}}s photometry include epochs from -10 to +71 days. these data are used to constrain the progenitor system of sn 20... | post-maximum near-infrared spectra of sn 2014j: a search for interaction signatures |
the increasing number of synoptic surveys made by small robotic telescopes, such as the photometric catalina real-time transient survey (crts), provides a unique opportunity to discover variable sources and improves the statistical samples of such classes of objects. our goal is the discovery of magnetic cataclysmic va... | exploratory spectroscopy of magnetic cataclysmic variables candidates and other variable objects |
we study the relationship between molecular gas and dust in the california molecular cloud over an unprecedented dynamic range of cloud depth (av = 3-60 mag). we compare deep herschel-based measurements of dust extinction with observations of the 12co, 13co, and c18o j = 2 - 1 lines on sub-parsec scales across the clou... | probing the cold deep depths of the california molecular cloud: the icy relationship between co and dust |
brite-constellation is devoted to high-precision optical photometric monitoring of bright stars, distributed all over the milky way, in red and/or blue passbands. photometry from space avoids the turbulent and absorbing terrestrial atmosphere and allows for very long and continuous observing runs with high time resolut... | space photometry with brite-constellation |
in the second part of our series on integrated photonic spectrographs for astronomy, we present theoretical and experimental results on the design, simulation and characterization of custom-manufactured silica-on-silicon arrayed waveguide gratings (awgs) constructed using the three-stigmatic-point method. we derive sev... | design, simulation and characterization of integrated photonic spectrographs for astronomy ii: low-aberration generation-ii awg devices with three stigmatic points |
we search for optical transient sources with durations of ∼0.1 to ∼1.3 s using a data set obtained in the organized autotelescopes for serendipitous event survey (oases) observation campaign. since the oases observations were carried out using two independent wide-field and high-cadence observation systems monitored th... | detectability of optical transients with timescales of subseconds |
automated searches for strong gravitational lensing in optical imaging survey datasets often employ machine learning and deep learning approaches. these techniques require more example systems to train the algorithms than have presently been discovered, which creates a need for simulated images as training dataset supp... | deeplenstronomy: a dataset simulation package for strong gravitational lensing |
we present a novel intelligent quasar continuum neural network (iqnet), predicting the intrinsic continuum of any quasar in the rest-frame wavelength range of $1020 \, {\mathring{\rm a}}\le \lambda _{\text{rest}} \le 1600 \, {\mathring{\rm a}}$ . we train this network using high-resolution hubble space telescope/cosmic... | a deep learning approach to quasar continuum prediction |
india reached a major milestone in the area of space astronomy with the successful launch and post-launch operations of its first space observatory, astrosat. the success of this space observatory and the lessons learned must be utilized effectively to enlarge the footprint of indian space astronomy in the internationa... | an overview of the proposed indian spectroscopic and imaging space telescope |
we present the discovery that atlas18mlw was a tidal disruption event (tde) in the galaxy wisea j073544.83+663717.3, at a luminosity distance of 334 mpc. initially discovered by the asteroid terrestrial impact last alert system (atlas) on 2018 march 17.3, the tde nature of the transient was uncovered only recently with... | scat uncovers atlas's first tidal disruption event atlas18mlw: a faint and fast tde in a quiescent balmer strong galaxy |
we investigate the possibility of determining the mass distribution of a gravitational lens via lensing observations. we consider an extended, compact gravitational lens, representing its static external gravitational potential via an infinite set of symmetric trace free (stf) multipole moments. within the wave-optical... | recovering the mass distribution of an extended gravitational lens |
the solar gravitational lens (sgl) offers unique capabilities for direct high-resolution imaging of faint, distant objects, such as exoplanets. for that purpose, in the near future, a spacecraft carrying a meter-class telescope with a solar coronagraph would be placed in the focal region of the sgl. that region begins ... | navigating stellar wobbles for imaging with the solar gravitational lens |
we searched for diffuse interstellar bands (dibs) in the 0.91 < λ < 1.33 μm region by analyzing the near-infrared (nir) high-resolution (r = 20,000 and 28,000) spectra of 31 reddened early-type stars (0.04 < e(b - v) < 4.58) and an unreddened reference star. the spectra were collected using the winered spec... | survey of near-infrared diffuse interstellar bands in y and j bands. i. newly identified bands |
context. the response of imaging atmospheric cherenkov telescopes to incident γ-ray-initiated showers in the atmosphere changes as the telescopes age due to exposure to light and weather. these aging processes affect the reconstructed energies of the events and γ-ray fluxes.aims: this work discusses the implementation ... | the throughput calibration of the veritas telescopes |
magnetic cataclysmic variables (cvs) are luminous galactic x-ray sources, which have been difficult to find in purely optical surveys due to their lack of outburst behavior. the erosita telescope on board the spektr-rg mission is conducting an all-sky x-ray survey and recently released the public erosita final equatori... | discovery of two polars from a crossmatch of ztf and the srg/efeds x-ray catalog |
we present a comprehensive analysis of 653 optical candidate counterparts reported during the third gravitational-wave (gw) observing run. our sample concentrates on candidates from the 15 events (published in gwtc-2, gwtc-3, or not retracted on gracedb) that had a >1% chance of including a neutron star in order to ... | a systematic exploration of kilonova candidates from neutron star mergers during the third gravitational-wave observing run |
in bayesian estimation theory, the estimator ${\hat \theta} = e[\theta|l]$ attains the minimum mean squared error (mmse) for estimating a scalar parameter of interest $\theta$ from the observation of $l$ through a noisy channel $p_{l|\theta}$, given a prior $p_\theta$ on $\theta$. in quantum sensing tasks, the user get... | quantum multi-parameter adaptive bayesian estimation and application to super-resolution imaging |
metallic aluminum mirrors remain the best choice for high reflectance applications at ultraviolet wavelengths (90 to 320 nm) and maintain good performance through optical and infrared wavelengths. transparent protective coatings are required to prevent the formation of an oxide layer, which severely degrades reflectanc... | performance and prospects of far ultraviolet aluminum mirrors protected by atomic layer deposition |
infrared (ir) spectra of the hydrocarbon ices c3h8 (propane), c3h6 (propylene, propene), and c3h4 (propyne, methylacetylene) are relevant to the study of the low-temperature chemistry and spectroscopy of objects within and beyond the solar system, but ir band strengths and absorption coefficients are lacking for these ... | infrared spectra and optical constants of astronomical ices: iii. propane, propylene, and propyne |
moons (the multi-object optical and near-infrared spectrograph) is a third-generation instrument for the eso very large telescope (vlt). the large collecting area offered by the vlt (8.2 m diameter), combined with the large multiplex and wavelength coverage (optical to near-ir: 0.64 μm - 1.8 μm) of moons will provide t... | moons: a new powerful multi-object spectrograph for the vlt |
more than 500 diffuse interstellar bands (dibs) have been observed in astronomical spectra, and their signatures and correlations in different environments have been studied over the past decades to reveal clues about the nature of the carriers. we compare the equivalent widths of the dibs, normalized to the amount of ... | families and clusters of diffuse interstellar bands: a data-driven correlation analysis |
we investigated the reliability of our silicon atomic model and the influence of non-local thermodynamical equilibrium (nlte) on the formation of neutral silicon (si i) lines in the near-infrared (near-ir) h-band. we derived the differential si abundances for 13 sample stars with high-resolution h-band spectra from the... | nlte analysis of high-resolution h-band spectra. i. neutral silicon |
we present results on the structural properties of massive passive galaxies in three clusters at 1.39 < z < 1.61 from the kmos cluster survey. we measure light-weighted and mass-weighted sizes from optical and near-infrared hubble space telescope imaging and spatially resolved stellar mass maps. the rest-frame r-... | the kmos cluster survey (kcs). ii. the effect of environment on the structural properties of massive cluster galaxies at redshift 1.39 < z < 1.61 |
we present a catalog of multi-band forced photometry in the cdfs and xmm-lss fields. we used the tractor image-modeling software to produce de-blended photometry across 13 to 15 optical/infrared bands and determine photometric redshifts. our catalog, which is publicly available on irsa, contains ~1.5 million sources an... | multi-band tractor forced photometry and redshifts in the cdfs and xmm-lss fields |
the high-fidelity modelling of optical turbulence is critical to the design and operation of a new class of emerging highly sophisticated astronomical telescopes and adaptive optics instrumentation. in this study, we perform retrospective simulations of optical turbulence over the hawaiian islands using a mesoscale mod... | mesoscale modelling of optical turbulence in the atmosphere: the need for ultrahigh vertical grid resolution |
the ccat-prime telescope is a 6-meter aperture, crossed-dragone telescope, designed for millimeter and sub-millimeter wavelength observations. it will be located at an altitude of 5600 meters, just below the summit of cerro chajnantor in the high atacama region of chile. the telescope's unobscured optics deliver a fiel... | ccat-prime: a novel telescope for sub-millimeter astronomy |
interactions between electrons and photons are a source of rich physics from atomic to astronomical scales. here, we examine a new kind of electron-photon interaction in which an electron, modulated by light, radiates multiple harmonics of plasmons. the emitted plasmons can be femtosecond in duration and nanometer in s... | ultrafast multiharmonic plasmon generation by optically dressed electrons |
second order intensity correlations of speckle illumination are extensively used in imaging applications that require going beyond the rayleigh limit. the theoretical analysis shows that significantly improved imaging can be extracted from the study of increasingly higher order intensity cumulants. we provide experimen... | beyond sub-rayleigh imaging via high order correlation of speckle illumination |
star tracker is one of the most promising optical attitude measurement devices and it is widely used in spacecraft for its high accuracy. however, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. the authenticity of the accuracy measurement method of a star tracker will eventua... | an accuracy measurement method for star trackers based on direct astronomic observation |
we have conducted a near-infrared monitoring campaign at the uk infrared telescope, of the local group spiral galaxy m33 (triangulum). the main aim was to identify stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolve... | the uk infrared telescope m33 monitoring project - iv. variable red giant stars across the galactic disc |
aluminum is the heaviest light element displaying large star-to-star variations in galactic globular clusters (gcs). this element may provide additional insight into the origin of the multiple populations, now known to be common place in gcs, and also the nature of the first-generation stars responsible for a cluster's... | light-element abundances of giant stars in the globular cluster m71 (ngc 6838) |
the gravitational field of the sun will focus light from a distant source to a focal point at a minimal distance of 550 astronomical units from the sun. a proposed mission to this gravitational focus could use the sun as a very large lens, allowing (in principle) a large amplification of signal from the target, and a v... | mission to the gravitational focus of the sun: a critical analysis |
due to the increasing dimension, complexity and cost of the future astronomical surveys, new technologies enabling more compact and simpler systems are required. the development of curved detectors allows to enhance the performances of the optical system used (telescope or astronomical instrument), while keeping the sy... | curved detectors for astronomical applications: characterization results on different samples |
we report on the extensively upgraded cassegrain spectrograph on the south african astronomical observatory (saao) 1.9-m telescope. the introduction of new collimator and camera optics, a new detector and controller, a rear-of-slit viewing camera to facilitate acquisition, and a new instrument control and quick-look da... | spupnic (spectrograph upgrade: newly improved cassegrain): a versatile and efficient low- to medium-resolution, long-slit spectrograph on the south african astronomical observatory's 1.9-m telescope |
the daniel k. inouye solar telescope (dkist) is designed to deliver accurate spectropolarimetric calibrations across a wide wavelength range and large field of view for solar disk, limb, and coronal observations. dkist instruments deliver spectral resolving powers of up to 300,000 in multiple cameras of multiple instru... | polarization modeling and predictions for daniel k. inouye solar telescope part 5: impacts of enhanced mirror and dichroic coatings on system polarization calibration |
skypy is an open-source python package for simulating the astrophysical sky. it comprises a library of physical and empirical models across a range of observables and a command-line script to run end-to-end simulations. the library provides functions that sample realisations of sources and their associated properties f... | skypy: a package for modelling the universe |
recent advances in growth of hg1- x cd x te films on large-area (7 cm × 7.5 cm) cdznte (czt) substrates is presented. growth of hg1- x cd x te with good uniformity on large-area wafers is achieved using a riber 412 molecular beam epitaxy (mbe) tool designed for growth of hg1- x cd x te compounds. the reactor is equippe... | characterization of hgcdte films grown on large-area cdznte substrates by molecular beam epitaxy |
we present infrared k'-band (2.1 μm) and l'-band (3.8 μm) high-spatial-resolution (<0"3) imaging observations of 17 nearby (z < 0.17) ultraluminous infrared galaxies (ulirgs) assisted with the adaptive optics of the subaru telescope. we search for compact red k' - l' color emission as the indicator of luminous ac... | subaru infrared adaptive optics-assisted high-spatial-resolution imaging search for luminous dual active galactic nuclei in nearby ultraluminous infrared galaxies |
the hα spectral line is a well-studied absorption line revealing properties of the highly structured and dynamic solar chromosphere. typical features with distinct spectral signatures in hα include filaments and prominences, bright active-region plages, superpenumbrae around sunspots, surges, flares, ellerman bombs, fi... | classification of high-resolution solar hα spectra using t-distributed stochastic neighbor embedding |
the lobster eye telescope is promising for large-field x ray imaging in astronomy. the special structure of the lobster eye system makes the focal plane a sphere, resulting in detector defocus when the field is large. in this study, we established a model based on the principle of lobster eye imaging and simulated the ... | detection system of the lobster eye telescope with large field of view |
the prototype schwarzschild-couder telescope (psct) is a candidate for a medium-sized telescope in the cherenkov telescope array. the psct is based on a dual-mirror optics design that reduces the plate scale and allows for the use of silicon photomultipliers as photodetectors. the prototype psct camera currently has on... | design and performance of the prototype schwarzschild-couder telescope camera |
a large number of unidentified sources found by astronomical surveys and other observations necessitate the use of an automated classification technique based on machine learning (ml) methods. the aim of this paper is to find a suitable automated classifier to identify the point x-ray sources in the chandra source cata... | automated classification of chandra x-ray point sources using machine learning methods |
we present gran telescopio canarias (gtc) spectroscopic confirmations of 55 faint planetary nebulae (pne) candidates discovered largely in the int photometric h α survey (iphas) of the northern galactic plane by our pro-am collaboration. we confirm 46 of them as 'true' (t), 4 as 'likely' (l), and 5 as 'possible' (p) pn... | grantecan spectroscopic observations and confirmations of planetary nebulae candidates in the northern galactic plane |
aero-optical beam control relies on the development of low-latency forecasting techniques to quickly predict wavefronts aberrated by the turbulent boundary layer around an airborne optical system, and its study applies to a multidomain need from astronomy to microscopy for high-fidelity laser propagation. we leverage t... | dynamic mode decomposition for aero-optic wavefront characterization |
the inner regions of protoplanetary disks host many complex physical processes such as star-disk interactions, magnetic fields, planet formation, and the migration of new planets. to study directly this region requires milliarcsecond angular resolution, beyond the diffraction limit of the world's largest optical telesc... | imaging the inner astronomical unit of the herbig be star hd 190073 |
the burst observer and optical transient exploring system (bootes) was first designed as an asset of autonomous telescopes that started to be deployed in 1998, taking 24 years to be fully developed around the earth. nowadays bootes has became a global network of robotic telescopes, being the first one present in all co... | the burst observer and optical transient exploring system in the multi-messenger astronomy era |
a white light illuminated etalon is a valuable resource for spectrograph calibration in radial velocity exoplanet detection, and other astronomical applications. these etalons benefit from low drift (${\sim} 10^{-11}$/day) and well-characterized stability of their mode structure. however, measurements of several etalon... | a resolution to the mystery of an etalon that is optically expanding and contracting at the same time |
context. young stellar systems actively accrete from their circumstellar disk and simultaneously launch outflows. the physical link between accretion and ejection processes remains to be fully understood.aims: we investigate the structure and dynamics of magnetospheric accretion and associated outflows on a scale small... | stable accretion and episodic outflows in the young transition disk system gm aurigae. a semester-long optical and near-infrared spectrophotometric monitoring campaign |
we investigate the generation of optical frequency combs through a cascade of four-wave mixing processes in nonlinear fibres with optimised parameters. the initial optical field consists of two continuous-wave lasers with frequency separation larger than 40 ghz (312.7 pm at 1531 nm). it propagates through three nonline... | generation of optical frequency combs via four-wave mixing processes for low- and medium-resolution astronomy |
the chandra x-ray observatory (cxo) was launched almost 19 years ago and has been delivering spectacular science over the course of its mission. the advanced ccd imager spectrometer (acis) is the prime instrument on the satellite, conducting over 90% of the observations. the ccds operate at a temperature of -120°c and ... | the complicated evolution of the acis contamination layer over the mission life of the chandra x-ray observatory |
the 100-m x-ray test facility of the institute of high energy physics (ihep) was initially proposed in 2012 for the test and calibration of the x-ray detectors of the hard x-ray modulation telescope (hxmt) with the capability to support future x-ray missions. the large instrument chamber connected with a long vacuum tu... | the 100-m x-ray test facility at ihep |
in this experiment, we created a multiple-input neural network, consisting of convolutional and multilayer neural networks. with this setup the selected highest-performing neural network was able to distinguish variable stars based on the visual characteristics of their light curves, while taking also into account addi... | variable star classification with a multiple-input neural network |
interference fringes are a major source of systematic error in astronomical spectropolarimeters. we apply the berreman formalism with recent spatial fringe aperture averaging estimates to design and fabricate new fringe-suppressed polarization optics for several daniel k. inouye solar telescope (dkist) use cases. we su... | polarization modeling and predictions for daniel k. inouye solar telescope, part 6: fringe mitigation with polycarbonate modulators and optical contact calibration retarders |
in this paper, we use a non-kolmogorov power spectrum with an effective anisotropic parameter to include the effect of anisotropy at different scales. by using the spectrum, we theoretically analyze the effect of anisotropy on turbulence parameters such as long-term beam spread and scintillation for laser beams propaga... | optical turbulence with anisotropy at different scales and its effect on laser beam propagation along vertical paths |
we have realized a comb system with a 30 ghz mode spacing, 62 % available wavelength coverage in the visible region, and nearly 40 db spectral contrast by combining a robust erbium-doped-fiber-based femtosecond laser, mode filtering with newly designed optical cavities, and broadband-visible-range comb generation using... | erbium-doped-fiber-based broad visible range frequency comb with a 30 ghz mode spacing for astronomical applications |
in astronomy and related fields there is a pressing need to efficiently inject light, transmitted through the atmosphere, into a single-mode fibre. however this is extremely difficult due to the large, rapidly changing aberrations imprinted on the light by the turbulent atmosphere. an adaptive optics system must be use... | optimal broadband starlight injection into a single-mode fibre with integrated photonic wavefront sensing |
the ultraviolet transient astronomical satellite (ultrasat) is a scientific uv space telescope that will operate in geostationary orbit. the mission, targeted to launch in 2024, is led by the weizmann institute of science (wis) in israel and the israel space agency (isa). deutsches elektronen synchrotron (desy) in germ... | design of the ultrasat uv camera |
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