abstract stringlengths 3 192k | title stringlengths 4 857 |
|---|---|
one of the reasons for climate change (i.e., stratospheric ozone concentrations) is connected with the variations in optical thickness of aerosols in the upper sphere of the atmosphere (at altitudes over 30 km). therefore, aerosol and gas components of the atmosphere are crucial in the study of the ultraviolet (uv) rad... | tiny ultraviolet polarimeter for earth stratosphere from space investigation |
stellar spectral classification is a fundamental tool of modern astronomy, providing insight into physical characteristics such as effective temperature, surface gravity, and metallicity. accurate and fast spectral typing is an integral need for large all-sky spectroscopic surveys like the sloan digital sky survey (sds... | classifying single stars and spectroscopic binaries using optical stellar templates |
star formation in the universe's most massive galaxies proceeds furiously early in time but then nearly ceases. plenty of hot gas remains available but does not cool and condense into star-forming clouds. active galactic nuclei (agns) release enough energy to inhibit cooling of the hot gas, but energetic arguments alon... | a black hole feedback valve in massive galaxies |
context. theoretically, rotation-induced chemical mixing in massive stars has far reaching evolutionary consequences, affecting the sequence of morphological phases, lifetimes, nucleosynthesis, and supernova characteristics.aims: using a sample of 72 presumably single o-type giants to supergiants observed in the contex... | the vlt-flames tarantula survey. xxv. surface nitrogen abundances of o-type giants and supergiants |
we report the discovery of a warm neptune and a hot sub-neptune transiting toi-421 (bd-14 1137, tic 94986319), a bright (v = 9.9) g9 dwarf star in a visual binary system observed by the transiting exoplanet survey satellite (tess) space mission in sectors 5 and 6. we performed ground-based follow-up observations—compri... | the multiplanet system toi-421 |
reconfigurable photonic circuits have applications ranging from next-generation computer architectures to quantum networks, coherent radar and optical metamaterials. however, complete reconfigurability is only currently practical on millimetre-scale device footprints. here, we overcome this barrier by developing an on-... | free spectral range electrical tuning of a high quality on-chip microcavity |
we describe the remote facilities operated by the southeastern association for research in astronomy (sara) , a consortium of colleges and universities in the us partnered with lowell observatory, the chilean national telescope allocation committee, and the instituto de astrofísica de canarias. sara observatories compr... | the remote observatories of the southeastern association for research in astronomy (sara) |
we present a comprehensive methodology for the simulation of astronomical images from optical survey telescopes. we use a photon monte carlo approach to construct images by sampling photons from models of astronomical source populations, and then simulating those photons through the system as they interact with the atm... | simulation of astronomical images from optical survey telescopes using a comprehensive photon monte carlo approach |
we report the results of our exploratory program carried out with the southern astrophysical research telescope aimed at associating counterparts and establishing the nature of the fermi unidentified γ-ray sources (ugss). we selected the optical counterparts of six ugss from the fermi catalog on the basis of our recent... | optical spectroscopic observations of γ-ray blazar candidates. iii. the 2013/2014 campaign in the southern hemisphere |
quasars may have played a key role in limiting the stellar mass of massive galaxies. identifying those quasars in the process of removing star formation fuel from their hosts is an exciting ongoing challenge in extragalactic astronomy. in this paper, we present x-ray observations of 11 extremely red quasars (erqs) with... | high-redshift extremely red quasars in x-rays |
the observation of gravitational wave signals from binary black hole and binary neutron star mergers has established the field of gravitational wave astronomy. it is expected that future networks of gravitational wave detectors will possess great potential in probing various aspects of astronomy. an important considera... | localization of binary neutron star mergers with second and third generation gravitational-wave detectors |
mergers of neutron stars (nss) and black holes (bhs) are nowadays observed routinely thanks to gravitational-wave (gw) astronomy. in the isolated binary-evolution channel, a common-envelope (ce) phase of a red supergiant (rsg) and a compact object is crucial to sufficiently shrink the orbit and thereby enable a merger ... | evolution and final fate of massive post-common-envelope binaries |
knowledge of the spectrograph's instrumental profile (ip) provides important information needed for wavelength calibration and for the use in scientific analyses. this work develops new methods for ip reconstruction in high resolution spectrographs equipped with laser frequency comb calibration (lfc) systems and assess... | a new method for instrumental profile reconstruction of high resolution spectrographs |
the mg ii λλ2796, 2803 doublet has been suggested as a useful indirect indicator for the escape of lyα and lyman continuum (lyc) photons in local star-forming galaxies. however, studies to date have focused on small samples of galaxies with strong mg ii or strong lyc emission. here, we present the first study of mg ii ... | the low-redshift lyman continuum survey: optically thin and thick mg ii lines as probes of lyman continuum escape |
the probe far-infrared mission for astrophysics (prima) is under study as a potential far-ir space mission, featuring actively cooled optics, and both imaging and spectroscopic instrumentation. to fully take advantage of the low background afforded by a cold telescope, spectroscopy with prima requires detectors with a ... | characterization of a far-infrared kinetic inductance detector prototype for prima |
in this letter, we measure the rest-frame optical and near-infrared sizes of ten quiescent candidates at 3<z<5, first reported by carnell et al. (2023a). we use james webb space telescope (jwst) near-infrared camera (nircam) f277w and f444w imaging obtained through the public ceers early release science (ers) pro... | remarkably compact quiescent candidates at 3<z<5 in jwst-ceers |
ultraviolet spectroscopy provides unique insights into the structure of matter with applications ranging from fundamental tests to photochemistry in the earth's atmosphere and astronomical observations from space telescopes. at longer wavelengths, dual-comb spectroscopy with two interfering laser frequency combs has ev... | near-ultraviolet photon-counting dual-comb spectroscopy |
the vera c. rubin observatory is preparing to execute the most ambitious astronomical survey ever attempted, the legacy survey of space and time (lsst). currently the final phase of construction is under way in the chilean andes, with the observatory's ten-year science mission scheduled to begin in 2025. rubin's 8.4-me... | overview of the distributed image processing infrastructure to produce the legacy survey of space and time |
searching for low energy counterparts of γ -rays sources is one of the major challenges in modern γ -ray astronomy. in the third fermi source catalog about 30% of detected sources are unidentified/unassociated gamma-ray sources (ugss). we recently started an optical spectroscopic follow up campaign to confirm the blaza... | optical spectroscopic observations of gamma-ray blazar candidates. vii. follow-up campaign in the southern hemisphere |
the pyramid wave front sensor (pywfs) has become increasingly popular to use in adaptive optics (ao) systems due to its high sensitivity. the main drawback of the pywfs is that it is inherently nonlinear, which means that classic linear wave front reconstruction techniques face a significant reduction in performance at... | nonlinear wave front reconstruction from a pyramid sensor using neural networks |
the lobster eye imager for astronomy (leia), a pathfinder of the wide-field x-ray telescope of the einstein probe mission, was successfully launched onboard the satech-01 satellite of the chinese academy of sciences on 2022 july 27. in this paper, we introduce the design and on-ground test results of the leia instrumen... | the lobster eye imager for astronomy onboard the satech-01 satellite |
we combine asteroseismology, optical high-resolution spectroscopy, and kinematic analysis for 26 halo red giant branch stars in the kepler field in the range of -2.5 < [fe/h] < -0.6. after applying theoretically motivated corrections to the seismic scaling relations, we obtain an average mass of 0.97 ± 0.03 m⊙ fo... | star formation timescales of the halo populations from asteroseismology and chemical abundances |
wide-field small aperture telescopes are widely used for optical transient observations. detection and classification of astronomical targets in observed images are the most important and basic step. in this paper, we propose an astronomical target detection and classification framework based on deep neural networks. o... | detection and classification of astronomical targets with deep neural networks in wide-field small aperture telescopes |
the orbital parameters of warm jupiters serve as a record of their formation history, providing constraints on formation scenarios for giant planets on close and intermediate orbits. here, we report the discovery of tic 237913194b, detected in full-frame images from sectors 1 and 2 of the transiting exoplanet survey sa... | a highly eccentric warm jupiter orbiting tic 237913194 |
we present the implementation of a two-moment-based general-relativistic multigroup radiation transport module in the general-relativistic multigrid numerical (gmunu) code. on top of solving the general-relativistic magnetohydrodynamics and the einstein equations with conformally flat approximations, the code solves th... | general-relativistic radiation transport scheme in gmunu. i. implementation of two-moment-based multifrequency radiative transfer and code tests |
we comprehensively study the variability of miras in the large magellanic cloud by simultaneously analyzing light curves in 14 bands in the range of 0.5-24 μm. we model over 20 yr long, high-cadence i-band light curves collected by the optical gravitational lensing experiment (ogle) and fit them to light curves collect... | multiwavelength properties of miras |
we present three epochs of early-time ultraviolet (uv) and optical hst/stis spectroscopy of the young, nearby type iip supernova (sn) 2021yja. we complement the hst data with two earlier epochs of swift uvot spectroscopy. the hst and swift uvot spectra are consistent with those of other well-studied type iip sne. the u... | early-time ultraviolet spectroscopy and optical follow-up observations of the type iip supernova 2021yja |
optical spectra of galaxies and quasars from large cosmological surveys are used to measure redshifts and infer distances. they are also rich with information on the intrinsic properties of these astronomical objects. however, their physical interpretation can be challenging due to the substantial number of degrees of ... | reconstructing and classifying sdss dr16 galaxy spectra with machine-learning and dimensionality reduction algorithms |
we have observed the class 0/i protostellar system ced110 irs4 at an angular resolution of 0.″05 (∼10 au) as part of the atacama large millimeter/submillimeter array large program, early planet formation in embedded disks. the 1.3 mm dust continuum emission reveals that ced110 irs4 is a binary system with a projected s... | early planet formation in embedded disks (edisk). v. possible annular substructure in a circumstellar disk in the ced110 irs4 system |
we report new total-intensity visible-light high-contrast imaging of the tw hya disk taken with the space telescope imaging spectrograph (stis) on the hubble space telescope. this represents the first published images of the disk with stis since 2016, when a moving shadow on the disk surface was reported. we continue t... | the surprising evolution of the shadow on the tw hya disk |
this invited snowmass 2021 white paper highlights the power of joint-analysis of astronomical transients in advancing hep science and presents research activities that can realize the opportunities that come with current and upcoming projects. transients of interest include gravitational wave events, neutrino events, s... | snowmass2021 cosmic frontier cf6 white paper: multi-experiment probes for dark energy -- transients |
ngc 5548 is one of the active galactic nuclei (agns) selected for our long-term spectroscopic monitoring with the lijiang 2.4 m telescope, aiming at investigating the origin and evolution of broad-line regions (blrs), accurately measuring the mass of supermassive black holes (smbhs), and understanding the structure and... | supermassive black hole and broad-line region in ngc 5548: results from five-season reverberation mapping |
we propose a theoretical explanation of absorption/emission line systems in classical novae based on a fully self-consistent nova explosion model. we found that a reverse shock is formed far outside the photosphere (≳1013 cm) because later-ejected mass with a faster velocity collides with earlier-ejected matter. optica... | a strong shock during a nova outburst: an origin of multiple velocity systems in optical spectra and of high-energy emissions |
we formulate a parameterized model of embedded protostellar disks and test its ability to estimate disk properties by fitting dust-continuum observations. the main physical assumptions of our model are motivated by a recent theoretical study of protostellar disk formation; these assumptions include that the disk should... | testing a new model of embedded protostellar disks against observations: the majority of orion class 0/i disks are likely warm, massive, and gravitationally unstable |
the obscuring structure surrounding active galactic nuclei (agn) can be explained as a dust and gas flow cycle that fundamentally connects the agn with their host galaxies. this structure is believed to be associated with dusty winds driven by radiation pressure. however, the role of magnetic fields, which are invoked ... | alma polarimetry measures magnetically aligned dust grains in the torus of ngc 1068 |
the feynman path integral formalism has long been used for calculations of probability amplitudes. over the last few years, it has been extensively used to theoretically demonstrate that the usual application of the superposition principle in slit based interference experiments is often incorrect. this has caveat in bo... | measuring the deviation from the superposition principle in interference experiments |
we aim to select quasar candidates based on the two large survey databases, pan-starrs and allwise. exploring the distribution of quasars and stars in the colour spaces, we find that the combination of infrared and optical photometry is more conducive to select quasar candidates. two new colour criterions (yw1w2 and iw... | efficient selection of quasar candidates based on optical and infrared photometric data using machine learning |
it is known that the cross-correlation function (ccf) of a partially coherent vortex (pcv) beam shows a robust link with the radial and azimuthal mode indices. however, the previous proposals are difficult to measure the ccf in practical systems, especially in the case of astronomical objects. in this letter, we demons... | measuring mode indices of a partially coherent vortex beam with hanbury brown and twiss type experiment |
we introduce the 4 pi sky 'hub', a collection of open data-services and underlying software packages built for rapid, fully automated reporting and response to astronomical transient alerts. these packages build on the mature 'voevent' standardized message-format, and aim to provide a decentralized and open infrastruct... | the 4 pi sky transient alerts hub |
we examine the radial distributions of stellar populations in the globular cluster (gc) m15, using hubble space telescope/wide field camera 3 (wfc3) photometry of red giants in the nitrogen-sensitive f343n-f555w color. surprisingly, we find that giants with “primordial” composition (i.e., n abundances similar to those ... | radial distributions of sub-populations in the globular cluster m15: a more centrally concentrated primordial population |
we present the results of a long-term study designed to investigate the nature of micro-variability in blazars carried out primarily at the southeastern association for research in astronomy (sara) observatories. we analyzed micro-variability data of fifteen ovv quasars and bl lac sources collected from 1995 to 2021. t... | the nature of micro-variability in blazars |
in the past two decades high precision optical astronomical interferometry has benefited from the use of photonic technologies. today, near-infrared interferometric instruments deliver high-resolution, hyperspectral images of astronomical objects and combine up to 4 independent telescopes at a time thanks to integrated... | towards 3d-photonic, multi-telescope beam combiners for mid-infrared astrointerferometry |
we present the results of photometric and spectroscopic follow-ups of the lowest mass member candidates in the nearest ob association, upper scorpius (∼5-10 myr; 145 ± 17 pc), with the gran telescopio de canarias (gtc) and european southern observatory (eso) very large telescope (vlt). we confirm the membership of the ... | the optical + infrared l dwarf spectral sequence of young planetary-mass objects in the upper scorpius association |
context. blazars are the most numerous class of high-energy (he; e ∼ 50 mev−100 gev) and very high-energy (vhe; e ∼ 100 gev−10 tev) gamma-ray emitters. currently, a measured spectroscopic redshift is available for only about 50% of gamma-ray bl lacertae objects (bl lacs), mainly due to the difficulty in measuring relia... | optical spectroscopy of blazars for the cherenkov telescope array |
the flare-associated stellar coronal mass ejections (cmes) of solar-like and late-type stars profoundly impact the habitability of any expolanets in the systems. in this paper, we report the detection of flare-associated cmes for two m-dwarfs, thanks to a high-cadence survey carried out by the ground wide-angle camera ... | detection of flare-associated cme candidates on two m-dwarfs by gwac and fast, time-resolved spectroscopic follow-ups |
much of the progress in astronomy has been driven by instrumental developments, from the first telescopes to fiber fed spectrographs. in this review, we describe the field of astrophotonics, a combination of photonics and astronomical instrumentation that is gaining importance in the development of current and future i... | astrophotonics: astronomy and modern optics |
astronomical images are essential for exploring and understanding the universe. optical telescopes capable of deep observations, such as the hubble space telescope (hst), are heavily oversubscribed in the astronomical community. images also often contain additive noise, which makes denoising a mandatory step in post-pr... | learning to denoise astronomical images with u-nets |
sky survey telescopes and powerful targeted telescopes play complementary roles in astronomy. in order to investigate the nature and characteristics of the motions of very faint objects, a flexibly-pointed instrument capable of high astrometric accuracy is an ideal complement to current astrometric surveys and a unique... | faint objects in motion: the new frontier of high precision astrometry |
we present results from atacama large millimeter/submillimeter array (alma) 1.2 mm continuum observations of a sample of 27 star-forming galaxies at z = 2.1-2.5 from the mosfire deep evolution field survey with metallicity and star formation rate measurements from optical emission lines. using stacks of spitzer, hersch... | infrared spectral energy distributions and dust masses of sub-solar metallicity galaxies at z 2.3 |
using the hamilton-jacobi method, we study optical shadows of rotating bardeen-ads black holes in the presence of internal and external field contributions. precisely, we examine the shadow using one-dimensional real curves. by establishing the equations of motion of such ads black holes without external dark sectors, ... | optical shadows of rotating bardeen-ads black holes |
uv spectroscopy and spectropolarimetry hold the key to understanding certain aspects of massive stars that are largely inaccessible (or exceptionally difficult) with optical or longer wavelength observations. as we demonstrate, this is especially true for the rapidly-rotating be and bn stars, owing to their high temper... | ultraviolet spectropolarimetry: on the origin of rapidly rotating b stars |
we present orbital elements, orbital parallaxes, and individual component masses for 14 spatially resolved double-line spectroscopic binaries derived doing a simultaneous fit of their visual orbit and radial velocity curve. this was done by means of a markov chain monte carlo code developed by our group that produces p... | orbital elements and individual component masses from joint spectroscopic and astrometric data of double-line spectroscopic binaries |
groups and clusters of galaxies are a current focus of astronomical research owing to their role in determining the environmental effects on galaxies and the constraints they provide to cosmology. the erosita x-ray telescope on board the spectrum roentgen gamma observatory will be launched in 2019 and will have complet... | 4most consortium survey 5: erosita galaxy cluster redshift survey |
adaptive optics (ao) systems are an essential part of large astronomical telescopes and laser complexes operating through the atmosphere. each ao system is individually designed; the requirements for the components and the performance of an ao system are determined by the intensity and distribution of turbulent fluctua... | atmospheric research for adaptive optics |
we present a 45 ks chandra observation of the quasar ulas j1342+0928 at z = 7.54. we detect {14.0}-3.7+4.8 counts from the quasar in the observed-frame energy range 0.5-7.0 kev (6σ detection), representing the most distant non-transient astronomical source identified in x-rays to date. the present data are sufficient o... | chandra x-rays from the redshift 7.54 quasar ulas j1342+0928 |
astronircam is a cryogenic-cooled slit camera-spectrograph for the spectral range 1-2.5 μm installed at the nasmyth focus of the 2.5-meter telescope of the caucasian observatory of the sternberg astronomical institute of lomonosov moscow state university. the instrument is equipped with a hawaii-2rg 2048×2048 hgcdte ar... | astronircam—the infrared camera-spectrograph for the 2.5-m telescope of sai caucasian observatory |
mid-infrared (ir) spectral region is of immense importance for astronomy, medical diagnosis, security and imaging due to the existence of the vibrational modes of many important molecules in this spectral range. therefore, there is a particular interest in miniaturization and integration of ir optical components. to th... | mid infrared polarization engineering via sub-wavelength biaxial hyperbolic van der waals crystals |
context. the study of the integrated properties of star-forming galaxies is central to understand their formation and evolution. some of these properties are extensive and therefore their analysis require totally covering and spatially resolved observations. among these properties, metallicity can be defined in spiral ... | the dependence of oxygen and nitrogen abundances on stellar mass from the califa survey |
context. ionized gas kinematics provide important clues to the dynamical structure of galaxies and hold constraints to the processes driving their evolution.aims: the motivation of this work is to provide an overall characterization of the kinematic behavior of the ionized gas of the galaxies included in the calar alto... | ionized gas kinematics of galaxies in the califa survey. i. velocity fields, kinematic parameters of the dominant component, and presence of kinematically distinct gaseous systems |
we installed two sets of astronomical site monitoring systems (asmss) at lijiang observatory (gmg), for the running of the 2.4-meter lijiang optical telescope (ljt) and the 1.6-meter multi-channel photometric survey telescope (mephisto). the mephisto is under construction. the asms has been running on robotic mode sinc... | astronomical site monitoring system at lijiang observatory |
we present the transmission spectrum of hat-p-12b through a joint analysis of data obtained from the hubble space telescope space telescope imaging spectrograph and wide field camera 3 and spitzer, covering the wavelength range 0.3-5.0 μm. we detect a muted water vapor absorption feature at 1.4 μm attenuated by clouds,... | optical to near-infrared transmission spectrum of the warm sub-saturn hat-p-12b |
we perform lyα radiative transfer calculations to reproduce the lyα properties of star-forming galaxies at high redshifts. we model a galaxy as a halo in which the density distributions of lyα sources and h i plus dust medium are described with exponential functions. we also consider an outflow of the medium that repre... | lyα radiative transfer: modeling spectrum and surface brightness profiles of lyα-emitting galaxies at z = 3-6 |
a modified method of determining vertical profiles of optical turbulence characteristics is proposed. based on data of observations on the large solar vacuum telescope, vertical profiles of the dimensionless turbulence parameter and structure constant of air refractive index fluctuations are obtained. optical turbulenc... | a method of determining optical turbulence characteristics by the line of sight of an astronomical telescope |
measuring blackbody parameters for objects hotter than a few 104 k with optical data alone is common in many astrophysical studies. however this process is prone to large errors because at those temperatures the optical bands are mostly sampling the rayleigh-jeans tail of the spectrum. here we quantify these errors by ... | errors when constraining hot blackbody parameters with optical photometry |
the atmospheres of gas giant planets are thought to be inhomogeneous due to weather and patchy clouds. we present two full nights of coronagraphic observations of the hr 8799 planets using the charis integral field spectrograph behind the scexao adaptive optics system on the subaru telescope to search for spectrophomom... | atmospheric monitoring and precise spectroscopy of the hr 8799 planets with scexao/charis |
the vista (visible and infrared survey telescope for astronomy) survey of the magellanic clouds system (vmc) is collecting deep ks-band time-series photometry of the pulsating variable stars hosted in the system formed by the two magellanic clouds and the bridge connecting them. in this paper, we have analysed a sample... | the vmc survey - xiii. type ii cepheids in the large magellanic cloud |
an overview is presented of the h2 quasar absorption method to search for a possible variation of the proton-electron mass ratio μ =mp/me on a cosmological time scale. the method is based on a comparison between wavelengths of absorption lines in the h2 lyman and werner bands as observed at high redshift with wavelengt... | colloquium: search for a drifting proton-electron mass ratio from h2 |
this paper addresses a reflection-type dual-band 2-bit coding metasurface (cm) design to achieve the dual-band functionalities in two different operating bands, independently. we are particularly interested to control linearly polarized incident waves by encoding the propagation or dynamic phase in order to realize and... | full controls of oam vortex beam and realization of retro and negative reflections at oblique incidence using dual-band 2-bit coding metasurface |
context. the abundance and spatial distribution of dwarf galaxies are excellent empirical benchmarks against which to test models of structure formation on small scales. the nearby centaurus group, with its two subgroups centered on cen a and m 83, stands out as an important alternative to the local group for scrutiniz... | distances from the tip of the red giant branch to the dwarf galaxies dw1335-29 and dw1340-30 in the centaurus group |
we perform a stacking analysis of planck, akari, infrared astronomical satellite, wide-field infrared survey explorer, and herschel images of the largest number of (candidate) protoclusters at z ∼ 3.8 selected from the hyper suprime-cam subaru strategic program. stacking the images of the 179 candidate protoclusters, t... | planck far-infrared detection of hyper suprime-cam protoclusters at z ∼ 4: hidden agn and star formation activity |
dark energy is one of the greatest scientific mysteries of today. the idea that dark energy originates from quantum vacuum fluctuations has circulated since the late '60s, but theoretical estimations of vacuum energy have disagreed with the measured value by many orders of magnitude, until recently. lifshitz theory app... | lifshitz cosmology: quantum vacuum and hubble tension |
gravitational lenses can magnify distant galaxies, allowing us to discover and characterize the stellar populations of intrinsically faint, quiescent galaxies that are otherwise extremely difficult to directly observe at high redshift from ground-based telescopes. here, we present the spectral analysis of two lensed, q... | a glimpse of the stellar populations and elemental abundances of gravitationally lensed, quiescent galaxies at z ≳ 1 with keck deep spectroscopy |
we present an updated model for the extragalactic background light (ebl) from stars and dust, over wavelengths ≈0.1-1000 μm. this model uses accurate theoretical stellar spectra, and tracks the evolution of star formation, stellar mass density, metallicity, and interstellar dust extinction and emission in the universe ... | modeling the extragalactic background light and the cosmic star formation history |
knowledge about the rotation properties of space debris objects is essential for the active debris removal missions, accurate re-entry predictions and to investigate the long-term effects of the space environment on the attitude motion change. different orbital regions and object's physical properties lead to different... | apparent rotation properties of space debris extracted from photometric measurements |
context. the advanced ligo and virgo gravitational wave observatories detected a signal on 2019 august 14 during their third observing run, named gw190814. a large number of electromagnetic facilities conducted follow-up campaigns in the search for a possible counterpart to the gravitational wave event, which was made ... | gw190814 follow-up with the optical telescope meerlicht |
context. thermal emission by stochastically heated dust grains (shgs) plays an important role in the radiative transfer (rt) problem for a dusty medium. it is therefore essential to verify that rt codes properly calculate the dust emission before studying the effects of spatial distribution and other model parameters o... | benchmarking the calculation of stochastic heating and emissivity of dust grains in the context of radiative transfer simulations |
context. high angular resolution images at a wide field of view are required for investigating solar physics and predicting space weather. ground-based observations are often subject to adaptive optics (ao) correction and post-facto reconstruction techniques to improve the spatial resolution. the combination of ground ... | wide field-of-view, high-resolution solar observation in combination with ground layer adaptive optics and speckle imaging |
a new wolter x-ray imager has been developed for the z machine to study the emission of warm (>15 kev) x-ray sources. a wolter optic has been adapted from observational astronomy and medical imaging, which uses curved x-ray mirrors to form a 2d image of a source with 5 × 5 × 5 mm3 field-of-view and measured 60-300-μ... | a wolter imager on the z machine to diagnose warm x-ray sources |
context. although the gaia catalogue on its own will be a very powerful tool, it is the combination of this highly accurate archive with other archives that will truly open up amazing possibilities for astronomical research. the advanced interoperation of archives is based on cross-matching, leaving the user with the f... | gaia data release 1. cross-match with external catalogues. algorithm and results |
we are undertaking a large survey of over 30 disks using the gemini planet imager (gpi) to see whether the observed dust structures match spectral energy distribution predictions and have any correlation with stellar properties. gpi can observe near-infrared light scattered from dust in circumstellar environments using... | irregular dust features around intermediate-mass young stars with gpi: signs of youth or misaligned disks? |
we present an analysis of 12 optically selected dual active galactic nucleus (agn) candidates at z < 0.34. each candidate was originally identified via double-peaked [o iii] λ5007 emission lines and received follow-up chandra and hubble space telescope (hst) observations. because the x-ray data are low-count (<10... | a second look at 12 candidate dual agns using baymax |
we present optical and infrared spectroscopy of v1309 sco, an object that erupted in 2008 in a stellar-merger event. during the outburst, v1309 sco displayed characteristics typical of red transients, a class of objects similar to v838 mon. our observations were obtained in 2009 and 2012, i.e. months and years after th... | post-outburst spectra of a stellar-merger remnant of v1309 scorpii: from a twin of v838 monocerotis to a clone of v4332 sagittarii |
the prime-focus infrared microlensing experiment (prime) will be the first to conduct a dedicated near-infrared microlensing survey by using a 1.8 m telescope with a wide field of view of 1.45 deg2 at the south african astronomical observatory. the major goals of the prime microlensing survey are to measure the microle... | prediction of planet yields by the prime-focus infrared microlensing experiment microlensing survey |
supernovae (sne) with photospheric spectra devoid of hydrogen and helium features are generally classified as sne ic. however, there is ongoing debate as to whether helium can be hidden in the ejecta of sne ic (that is, helium is present in the ejecta, but produces no obvious features in the spectra). we present the fi... | modeling type ic supernovae with tardis: hidden helium in sn 1994i? |
correlating beijing-arizona sky survey (bass) data release 3 (dr3) catalogue with the allwise data base, the data from optical and infrared information are obtained. the quasars from sloan digital sky survey are taken as training and test samples while those from lamost are considered as external test sample. we propos... | photometric redshift estimation of bass dr3 quasars by machine learning |
we have developed an electron tracking compton camera (etcc), which provides a well-defined point spread function (psf) by reconstructing a direction of each gamma as a point and realizes simultaneous measurement of brightness and spectrum of mev gamma-rays for the first time. here, we present the results of our on-sit... | first on-site true gamma-ray imaging-spectroscopy of contamination near fukushima plant |
localisation of gamma-ray interaction points in monolithic scintillator crystals can simplify the design and improve the performance of a future compton telescope for gamma-ray astronomy. in this paper we compare the position resolution of three monolithic scintillators: a 28×28×20 mm3 (length×breadth × thickness) labr... | localisation of gamma-ray interaction points in thick monolithic cebr3 and labr3:ce scintillators |
an important technique for discovering and characterizing planets beyond our solar system relies upon measurement of weak doppler shifts in the spectra of host stars induced by the influence of orbiting planets. a recent advance has been the introduction of optical frequency combs as frequency references. frequency com... | demonstration of a near-ir line-referenced electro-optical laser frequency comb for precision radial velocity measurements in astronomy |
astronomers have come to recognize the benefits of photonics, often in combination with optical systems, in solving longstanding experimental problems in earth-based astronomy. here, we explore some of the recent advances made possible by integrated photonics. we also look to the future with a view to entirely new kind... | astrophotonics: the rise of integrated photonics in astronomy |
context. high-mass x-ray binaries (hmxbs) are exceptional astrophysical laboratories that offer a rare glimpse into the physical processes that govern accretion on compact objects, massive-star winds, and stellar evolution. in a subset of the hmxbs, the compact objects accrete matter solely from winds of massive donor ... | the stellar and wind parameters of six prototypical hmxbs and their evolutionary status |
fu orionis-type objects (fuors) are young low-mass stars undergoing powerful accretion outbursts. the increased accretion is often accompanied by collimated jets and energetic, large-scale molecular outflows. the extra heating during the outburst may also induce detectable geometrical, chemical, and mineralogical chang... | v346 nor: the post-outburst life of a peculiar young eruptive star |
we demonstrate for the first time an efficient, photonic-based astronomical spectrograph on the 8-m subaru telescope. an extreme adaptive optics system is combined with pupil apodiziation optics to efficiently inject light directly into a single-mode fiber, which feeds a compact cross-dispersed spectrograph based on ar... | demonstration of an efficient, photonic-based astronomical spectrograph on an 8-m telescope |
the large optical/infrared telescope (lot) is a ground-based 12 m diameter optical/infrared telescope which is proposed to be built in the western part of china in the next decade. based on satellite remote sensing data, along with geographical, logistical and political considerations, three candidate sites were chosen... | site testing campaign for the large optical/infrared telescope of china: overview |
the prospect of extreme high-contrast astronomical imaging from space has inspired developments of new coronagraph methods for exoplanet imaging and spectroscopy. however, the requisite imaging contrast, at levels of 1 billion to one or better for the direct imaging of cool mature exoplanets in reflected visible starli... | hybrid lyot coronagraph for wfirst-afta: coronagraph design and performance metrics |
amorphous silicon has ideal properties for many applications in fundamental research and industry. however, the optical absorption is often unacceptably high, particularly for gravitational-wave detection. we report a novel ion-beam deposition method for fabricating amorphous silicon with unprecedentedly low unpaired e... | amorphous silicon with extremely low absorption: beating thermal noise in gravitational astronomy |
we provide an updated calibration of c iv λ 1549 broad emission line-based single-epoch (se) black hole (bh) mass estimators for active galactic nuclei (agns) using new data for six reverberation-mapped agns at redshift z=0.005{--}0.028 with bh masses (bolometric luminosities) in the range {10}6.5{--}{10}7.5 {m}⊙({10}4... | extending the calibration of c iv-based single-epoch black hole mass estimators for active galactic nuclei |
we present space-based ultraviolet/optical photometry and spectroscopy with the swift ultra-violet/optical telescope and hubble space telescope (hst), respectively, along with ground-based optical photometry and spectroscopy and near-infrared spectroscopy of supernova sn 2017erp. the optical light curves and spectra ar... | red and reddened: ultraviolet through near-infrared observations of type ia supernova 2017erp |
we present new high-resolution (r = λ/δλ ∼ 14,000) spectra of the two brightest he ii-transparent quasars in the far-uv at zem > 3.5, he2qs j2311-1417 (zem = 3.70) and he2qs j1630+0435 (zem = 3.81), obtained with the cosmic origins spectrograph on the hubble space telescope. in the predominantly saturated he ii abso... | new evidence for extended he i> reionization at z ≳ 3.5 from he ii lyman alpha and beta transmission spikes |
the hubble space telescope (hst) has been providing tremendous survey efficiency via its pure-parallel mode by observing another field in parallel with the primary instrument in operation for the primary observation. in this study, we present a new archival project, superborg, which aims at compiling data taken in extr... | superborg: search for the brightest of reionizing galaxies and quasars in hst parallel imaging data |
optical follow-up observations of optical afterglows of gamma-ray bursts are crucial to probe the geometry of outflows, emission mechanisms, energetics and burst environments. we performed the follow-up observations of grb 210205a and ztf21aaeyldq (at2021any) using the 3.6m devasthal optical telescope (dot) around one ... | revealing nature of grb 210205a, ztf21aaeyldq (at2021any) and follow-up observations with the 4k×4k ccd imager + 3.6m dot |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.