abstract stringlengths 3 192k | title stringlengths 4 857 |
|---|---|
solid ammonia (nh3) is the only nitrogen-containing polyatomic molecule reported in both interstellar and solar system ices. however, an examination of the literature reveals significant omissions and difficulties in earlier work that can hinder quantitative measurements of solid nh3 by infrared (ir) methods by both as... | ammonia ices revisited: new ir intensities and optical constants for solid nh3 |
spitzer's final infrared array camera observations of sn 1987a show the 3.6 and 4.5 μm emission from the equatorial ring (er) continues a period of steady decline. deconvolution of the images reveals that the emission is dominated by the ring, not the ejecta, and is brightest on the west side. decomposition of the marg... | final spitzer irac observations of the rise and fall of sn 1987a |
optical turbulence limits the angular resolution of ground-based astronomical telescopes. the key parameter of optical turbulence is seeing. in this study, seasonal variations of seeing estimated from differential image motion monitor measurements at the large solar telescope site are discussed. the large solar telesco... | application of neural networks to estimation and prediction of seeing at the large solar telescope site |
the morphology of particles is usually detected by microscopic imaging methods such as scanning electron microscope (sem). however, this type of direct observation relies on expensive equipment and requires complex preparations. inspired by the transit method in astronomy, a characterization system based on the scatter... | a particle morphology characterization system and its method based on particle scattering image recognition |
scattered light imaging techniques leveraging memory effects have been extensively investigated, yet most approaches are limited to operating in predominantly dark environments. the introduction of additional optical noise disrupts the fine structure of the original speckle pattern, undermining spatial correlation and ... | imaging through scattering media under strong ambient light interference via the lock-in process |
this paper presents a new approach to deriving far-infrared (fir) photometric redshifts for galaxies based on their reprocessed emission from dust at rest-frame fir through millimeter wavelengths. fir photometric redshifts ("fir-z") have been used over the past decade to derive redshift constraints for highly obscured ... | far-infrared photometric redshifts: a new approach to a highly uncertain enterprise |
by applying the newman-janis algorithm, we investigate optical behaviors of rotating ayón-beato-garcía black holes in four-dimensional einstein gauss-bonnet gravity. exploiting the hamilton-jacobi mechanism, we first obtain the needed null geodesic equations of motion. we then provide analytic and numerical methods to ... | shadow behaviors of rotating ayón-beato-garcía black holes in four-dimensional einstein gauss-bonnet gravity |
periodic quasars have been suggested to host supermassive binary black holes (bbhs) in their centers, and their optical/uv periodicities are interpreted as caused by either the doppler-boosting (db) effect of continuum emission from the disk around the secondary black hole (bh) or intrinsic accretion rate variation. ho... | variation of broad emission lines from qsos with optical/uv periodicity to test the interpretation of supermassive binary black holes |
star-forming galaxies are believed to be a major source of lyman continuum (lyc) radiation responsible for reionizing the early universe. direct observations of escaping ionizing radiation have however been sparse and with low escape fractions. in the local universe, only 10 emitters have been observed, with typical es... | neutral ism, lyα, and lyman-continuum in the nearby starburst haro11 |
a relatively unexplored phase space of transients and stellar variability is that of second and sub-second timescales. we describe a new optical observatory operating in the negev desert in israel, with a 55 cm aperture, a field of view of 2°6 × 2°6 (≈7 deg2) equipped with a high frame rate, low read noise, cmos camera... | the weizmann fast astronomical survey telescope (w-fast): system overview |
the total infrared (ir) luminosity (lir) can be used as a robust measure of a galaxy's star formation rate (sfr), even in the presence of an active galactic nucleus (agn), or when optical emission lines are weak. unfortunately, existing all sky far-ir surveys, such as the infrared astronomical satellite (iras) and akar... | the infrared luminosities of ∼332 000 sdss galaxies predicted from artificial neural networks and the herschel stripe 82 survey |
we present the development of a background-limited kilo-pixel imaging array of ultrawide bandwidth kinetic inductance detectors (kids) suitable for space-based thz astronomy applications. the array consists of 989 kids, in which the radiation is coupled to each kid via a leaky lens antenna, covering the frequency range... | ultrasensitive kilo-pixel imaging array of photon noise-limited kinetic inductance detectors over an octave of bandwidth for thz astronomy |
imaging and spectroscopy at (sub-)millimeter wavelengths are key frontiers in astronomy and cosmology. large area spectral surveys with moderate spectral resolution (r=50-200) will be used to characterize large-scale structure and star formation through intensity mapping surveys in emission lines such as the co rotatio... | wspec: a waveguide filter-bank focal plane array spectrometer for millimeter wave astronomy and cosmology |
the panoramic search for extraterrestrial intelligence (panoseti) experiment is designed to detect pulsed optical signals on nanosecond timescales. panoseti is therefore sensitive to cherenkov radiation generated by extensive air showers, and can be used for gamma-ray astronomy. each panoseti telescope uses a 0.5 m fre... | pev gamma-ray astronomy with panoramic optical seti telescopes |
over the past 16 years, nasa's chandra x-ray observatory has provided an unparalleled means for exploring the universe with its half-arcsecond angular resolution. chandra studies have deepened our understanding of galaxy clusters, active galactic nuclei, galaxies, supernova remnants, planets, and solar system objects a... | beyond chandra: the x-ray surveyor |
multi-object astronomical adaptive-optics (moao) is now a mature wide-field observation mode to enlarge the adaptive-optics-corrected field in a few specific locations over tens of arc-minutes. the work-scope provided by open-loop tomography and pupil conjugation is amenable to a spatio-angular linear-quadratic gaussia... | spatio-angular minimum-variance tomographic controller for multi-object adaptive-optics systems |
recent progress in telescope development has brought us different ways to observe protoplanetary disks: interferometers, space missions, adaptive optics, polarimetry, and time- and spectrally-resolved data. while the new facilities have changed the way we can tackle open problems in disk structure and evolution, there ... | a `rosetta stone' for protoplanetary disks: the synergy of multi-wavelength observations |
we map the surface of pluto using an unsupervised machine-learning technique using the near-infrared observations of the leisa/ralph instrument on board nasa's new horizons spacecraft. the principal-component-reduced gaussian mixture model was implemented to investigate the geographic distribution of the surface units ... | pluto's surface mapping using unsupervised learning from near-infrared observations of leisa/ralph |
the detection of gravitational waves from the binary neuron star merger gw170817 and electromagnetic counterparts grb170817a and at2017gfo kick-started the field of gravitational-wave multimessenger astronomy. the optically red to near-infrared emission ("red" component) of at2017gfo was readily explained as produced b... | prospects of gravitational-wave follow-up through a wide-field ultraviolet satellite: a dorado case study |
absorption spectroscopy is widely used in sensing and astronomy to understand remote molecular compositions. however, dispersive techniques require multichannel detection, reducing detection sensitivity while increasing instrument cost when compared to spectrophotometric methods. we present a novel non-dispersive infra... | spectrum-free integrated photonic remote molecular identification and sensing |
with the imminent start of the legacy survey for space and time (lsst) at the vera c. rubin observatory and several new space telescopes expected to begin operations later in this decade, both time-domain and wide-field astronomy are on the threshold of a new era. in this paper, we use a new multicomponent model for th... | white dwarfs in the era of the lsst and its synergies with space-based missions |
context. during its ongoing all-sky survey, the mikhail pavlinsky art-xc (astronomical roentgen telescope - x-ray concentrator) telescope on board the spectrum-roentgen-gamma (srg) observatory is set to discover new x-ray sources, many of which can be transient. here we report the discovery and multiwavelength follow-u... | peculiar x-ray transient srga j043520.9+552226/at2019wey discovered with srg/art-xc |
the advent of sensitive gravitational-wave (gw) detectors, coupled with wide-field, high-cadence optical time-domain surveys, raises the possibility of the first joint gw-electromagnetic detections of core-collapse supernovae (ccsne). for targeted searches of gws from ccsne, optical observations can be used to increase... | constraining the time of gravitational-wave emission from core-collapse supernovae |
for millimeter and submillimeter-wave astronomy, it is highly desirable to have vacuum windows within the receiver cryostat that exhibit low reflection, low loss, and a wide bandpass. the use of antireflective (ar) sub-wavelength structures (swss) on substrates has expanded the possibilities for creating new vacuum win... | optical measurements of the silicon vacuum window with anti-reflective sub-wavelength structure for aste band 10 |
adaptive optics (ao) systems have been developed throughout recent decades as a strategy to compensate for the effects of atmospheric turbulence, primarily caused by poor astronomical seeing. these systems reduce the wavefront distortions using deformable mirrors. several ao simulation tools have been developed, such a... | benefits of intelligent fuzzy controllers in comparison to classical methods for adaptive optics |
the 3d-drift and shift (3d-dash) program is a hubble space telescope (hst) wfc3 f160w imaging and g141 grism survey of the equatorial cosmos field. 3d-dash extends the legacy of hst near-infrared imaging and spectroscopy to degree-scale swaths of the sky, enabling the identification and study of distant galaxies (z >... | 3d-dash: the widest near-infrared hubble space telescope survey |
we report precision atmospheric spectroscopy of co2 using a laser heterodyne radiometer (lhr) calibrated with an optical frequency comb. using the comb calibrated lhr, we record spectra of atmospheric co2 near 1572.33 nm with a spectral resolution of 200 mhz, using sunlight as a light source. the measured co2 spectra e... | precision doppler shift measurements with a frequency comb calibrated laser heterodyne radiometer |
classical optical interferometry requires maintaining live, phase-stable links between telescope stations. this requirement greatly adds to the cost of extending to long baseline separations and limits on baselines will in turn limit the achievable angular resolution. here we describe a novel type of two-photon interfe... | towards quantum telescopes: demonstration of a two-photon interferometer for precision astrometry |
we present 87 candidates for rr lyrae variable stars in binary systems, based on our new search using the light-travel time effect (ltte) and observed - calculated (o - c) diagrams in the galactic bulge time-series photometry of the optical gravitational lensing experiment. out of these, 61 are new candidates, while 26... | studies of rr lyrae variables in binary systems. i. evidence of a trimodal companion mass distribution |
adaptive optics (ao) has revolutionized imaging in {fields} from astronomy to microscopy by correcting optical aberrations. in label-free microscopes, however, conventional ao faces limitations due to the absence of guidestar and the need to select an optimization metric specific to the sample and imaging process. here... | adaptive optical imaging with entangled photons |
a galaxy's morphological features encode details about its gas content, star formation history, and feedback processes, which play important roles in regulating its growth and evolution. we use deep convolutional neural networks (cnns) to learn a galaxy's optical morphological information in order to estimate its neutr... | connecting optical morphology, environment, and h i mass fraction for low-redshift galaxies using deep learning |
in this paper, we introduce the results of the statistical analysis of atmospheric characteristics at the site of the big telescope alt-azimuthal (bta) of the special astrophysical observatory (sao) of the russian academy of science (ras). the bta is the largest optical telescope in eurasia and is located near mt pastu... | atmospheric parameters at the 6-m big telescope alt-azimuthal site |
a compact green astro-comb with 43-ghz repetition rate is developed based on a ti:sapphire optical frequency comb (ofc) and a mode-selecting cavity. the ofc's large repetition rate of 1.6 ghz eases the requirements for the mode-selecting cavity. unnecessary frequency-modes of the ofc are suppressed down to $5 \times 10... | compact green ti:sapphire astro-comb with a 43 ghz repetition frequency |
context. within the framework of the second-generation instrumentation of the very large telescope interferometer of the european southern observatory we have developed the four-telescope beam combiner in integrated optics.aims: we optimized the performance of such beam combiners, for the first time in the near-infrare... | single-mode waveguides for gravity. i. the cryogenic 4-telescope integrated optics beam combiner |
the forecast for atmospheric and turbulence conditions above astronomical observatories is of interest to the astronomical community because it allows observations to be planned with maximum efficiency, a process called flexible scheduling. it can also be used to simulate long-term site testing to provide local informa... | contribution of statistical site learning to improve optical turbulence forecasting |
the large ultraviolet/optical/infrared surveyor (luvoir) is one of four large mission concepts currently undergoing community study for consideration by the 2020 astronomy and astrophysics decadal survey. luvoir is being designed to pursue an ambitious program of exoplanetary discovery and characterization, cosmic orig... | the luvoir ultraviolet multi-object spectrograph (lumos): instrument definition and design |
context. dz cha is a weak-lined t tauri star (wtts) surrounded by a bright protoplanetary disc with evidence of inner disc clearing. its narrow hα line and infrared spectral energy distribution suggest that dz cha may be a photoevaporating disc.aims: we aim to analyse the dz cha star + disc system to identify the mecha... | dz chamaeleontis: a bona fide photoevaporating disc |
we have investigated the shape of the extinction curve in the infrared up to 25μm for the orion a star-forming complex. the basis of this work is near-infrared data acquired with the visual and infrared survey telescope for astronomy, in combination with pan-starrs and mid-infrared spitzer photometry. we obtain colour ... | vision - vienna survey in orion. ii. infrared extinction in orion a |
phase retrieval is a problem present in many applications such as optics, astronomical imaging, computational biology and x-ray crystallography. recent work has shown that the phase can be better recovered when the acquisition architecture includes a coded aperture, which modulates the signal before diffraction, such t... | coded diffraction system in x-ray crystallography using a boolean phase coded aperture approximation |
recently, machine learning methods have presented a viable solution for the automated classification of image-based data in various research fields and business applications. scientists require a fast and reliable solution in order to handle increasingly large amounts of astronomical data. however, so far astronomers h... | image-based classification of variable stars: first results from optical gravitational lensing experiment data |
we report the design and characterization of a high performance integrated arbitrary filter from 1450 nm to 1640 nm. the filter's target spectrum is chosen to suppress the night-sky oh emission lines, which is critical for ground-based astronomical telescopes. this type of filter is featured by its large spectral range... | integrated arbitrary filter with spiral gratings: design and characterization |
aims: every 5.5 years, η car's light curve and spectrum change remarkably across all observed wavelength bands. these so-called spectroscopic events are most likely caused by the close approach of a companion. we compare the recent spectroscopic event in mid-2014 to the events in 2003 and 2009 and investigate long-term... | eta carinae's 2014.6 spectroscopic event: clues to the long-term recovery from its great eruption |
we report the discovery of an occultation event in the low-luminosity narrow-line seyfert 1 galaxy wpvs 007 in 2015 february and march. in concert with longer timescale variability, these observations place strong constraints on the nature and location of the absorbing material. swift monitoring has revealed a secular ... | variable reddening and broad absorption lines in the narrow-line seyfert 1 galaxy wpvs 007: an origin in the torus |
on small scales the observable universe is highly inhomogeneous, with galaxies and clusters forming a complex web of voids and filaments. the optical properties of such configurations can be quite different from the perfectly smooth friedmann-lemaȋtre-robertson-walker (flrw) solutions that are frequently used in cosmol... | ray tracing and hubble diagrams in post-newtonian cosmology |
we report on observations of the polarization of optical and γ-ray photons from the crab nebula and pulsar system using the galway astronomical stokes polarimeter (gasp), the hubble space telescope, advanced camera for surveys and the international gamma-ray astrophysics laboratory satellite (integral). these, when com... | a recent change in the optical and γ-ray polarization of the crab nebula and pulsar |
dimensionality reduction and matrix factorization techniques are important and useful machine-learning techniques in many fields. nonnegative matrix factorization (nmf) is particularly useful for spectral analysis and image processing in astronomy. i present the vectorized update rules and an independent proof of their... | nonnegative matrix factorization (nmf) with heteroscedastic uncertainties and missing data |
unburned carbon is potentially a powerful probe of type ia supernova (sn) explosion mechanisms. we present comprehensive optical and near-infrared (nir) data on the "transitional" type ia sn 2015bp. an early nir spectrum ( $t=-9.9$ days with respect to b-band maximum) displays a striking c i 1.0693 μm line at 11.9 × 10... | strong near-infrared carbon absorption in the transitional type ia sn 2015bp |
planetary nebulae (pns) consist of an ionized envelope surrounding a hot central star (cspn) that emits mostly at ultraviolet (uv) wavelengths. uv observations, therefore, provide important information on both the cspn and the nebula. we have matched the pns in the hong kong/australian astronomical observatory/strasbou... | catalog of planetary nebulae detected by galex and corollary optical surveys |
context. cosmic dust models are key ingredients in advancing our understanding of astronomical environments as diverse as interstellar clouds in galaxies, circumstellar envelopes around evolved and young stars, and protoplanetary disks. such models consist of several dust populations, each with different compositions a... | low-temperature optical constants of amorphous silicate dust analogues |
debris disks are dusty, optically thin structures around main-sequence stars. hd 106906ab is a short-period stellar binary, host to a wide-separation planet, hd 106906b, and a debris disk. only a few known systems include a debris disk and a directly imaged planet, and hd 106906 is the only one in which the planet is e... | millimeter dust emission and planetary dynamics in the hd 106906 system |
the next generation of large ground- and space-based optical telescopes will have segmented primary mirrors. co-phasing the segments requires a sensitive wavefront sensor capable of measuring phase discontinuities. the zernike wavefront sensor (zwfs) is a passive wavefront sensor that has been demonstrated to sense seg... | on-sky reconstruction of keck primary mirror piston offsets using a zernike wavefront sensor |
the legacy survey of space and time (lsst) at the vera c. rubin observatory will discover tens of thousands of extragalactic transients each night. the high volume of alerts demands immediate classification of transient types in order to prioritize observational follow-ups before events fade away. we use host galaxy fe... | classifying astronomical transients using only host galaxy photometry |
we present model spectral energy distribution (sed) fits to ultraviolet/optical/infrared observations for the 258 nearby galaxies in the local volume legacy survey, a sample dominated by lower-luminosity dwarf irregular systems. the data for each galaxy include up to 26 spatially-integrated broadband and narrowband flu... | spectral energy distributions for 258 local volume galaxies |
the clusters in the uv as engines (clues) survey is a cosmic origins spectrograph (cos) campaign aimed at acquiring the 1130-1770 å rest-frame spectroscopy of very young (<20 myr) and massive (>104 m ⊙) star clusters in galaxies that are part of the hubble treasury program legacy extragalactic uv survey. in this ... | clusters in the uv as engines (clues). i. survey presentation and fuv spectral analysis of the stellar light |
context. classical novae are the product of thermonuclear runaway-initiated explosions occurring on accreting white dwarfs.aims: v339 del (nova delphinus 2013) was one of the brightest classical novae of the last hundred years. spectroscopy and photometry are available from γ-rays through infrared at stages that have f... | the panchromatic spectroscopic evolution of the classical co nova v339 delphini (nova del 2013) until x-ray turnoff |
3c 66a is one of the most interesting blazars and one of our monitoring objects carried out with the 1.56 m telescope at sheshan station, shanghai astronomical observatory (shao). it has been monitored since 1996 december 11. in the present work, we show its optical light curves during the period of 1996 december 11-20... | optical photometric monitoring for 3c 66a during 1996-2009 and its periodicity analysis |
context. knowledge about the composition and structure of interstellar ices is mainly based on the comparison between astronomical and laboratory spectra of astrophysical ice analogues. carbon monoxide is one of the main components of the icy mantles of dust grains in the interstellar medium. because of its relevance, ... | combined infrared and raman study of solid co |
x-ray mirrors are widely used for synchrotron radiation, free-electron lasers, and astronomical telescopes. the short wavelength and grazing incidence impose strict limits on the permissible slope error. advanced polishing techniques have already produced mirrors with slope errors below 50 nrad root mean square (rms), ... | nano-precision metrology of x-ray mirrors with laser speckle angular measurement |
over the past few years, we have witnessed a substantial evolution in graphene optoelectronics. the tunability of the electronic structure of graphene has led to the next generation of carbon-based nano-photonic devices. motivated by the unique optical properties of graphene, in the present work, we show that the landa... | all-optical diffraction and ultrafast switching in a terahertz-driven quantized graphene system |
the near-infrared region offers a compelling window for interstellar communications, energy transfer, and transient detection due to low extinction and low thermal emission from dust. we have conducted a search for near-infrared (950-1650 nm) light pulses having durations less than 50 nanoseconds while observing 1280 a... | search for nanosecond near-infrared transients around 1280 celestial objects |
while deep learning has led to breakthroughs in many areas of computer science, its power has yet to be fully exploited in the area of adaptive optics (ao) and astronomy as a whole. in this paper we describe the first steps taken to apply deep, convolutional neural networks to the problem of wavefront reconstruction an... | wavefront reconstruction and prediction with convolutional neural networks |
we present a comparison of several difference image analysis (dia) techniques, in combination with machine learning (ml) algorithms, applied to the identification of optical transients associated to gravitational wave events. each technique is assessed based on the scoring metrics of precision, recall, and their harmon... | machine learning on difference image analysis: a comparison of methods for transient detection |
a large ground-based optical/infrared telescope is being planned for a world-class astronomical site in china. the cloud-free night percentage is the primary meteorological consideration for evaluating candidate sites. the data from gms and noaa satellites and the modis instrument were utilized in this research, coveri... | long-term analysis of clear nights using satellite data considering astronomical sites in western china |
the x-ray imaging and spectroscopy mission (xrism) is a recovery mission of astro-h (hitomi) launched in 2016. the resolve instrument on the xrism is an 6 × 6 array of silicon-thermistor microcalorimeters cooled down to 50 mk combined with a 5.6 m focal length x-ray telescope. its design inherits that of the soft x-ray... | cooling system for the resolve onboard xrism |
m104 (ngc 4594; the sombrero galaxy) is a nearby, well-studied elliptical galaxy included in scores of surveys focused on understanding the details of galaxy evolution. despite the importance of observations of m104, a consensus distance has not yet been established. here, we use newly obtained hubble space telescope o... | the distance to m104 |
context. the methylidyne radical ch is commonly used as a proxy for molecular hydrogen in the cold, neutral phase of the interstellar medium. the optical spectroscopy of ch is limited by interstellar extinction, whereas far-infrared observations provide an integral view through the galaxy. while the hf ground state abs... | unveiling the chemistry of interstellar ch. spectroscopy of the 2 thz n = 2 ← 1 ground state line |
we have matched the ultraviolet (uv) sources in guvcat_ais with optical databases that have similar depth and wide sky coverage. guvcat_ais has galaxy evolution explorer (galex) far-uv (fuv, λeff ∼ 1528 å) and near-uv (nuv, λeff ∼ 2310 å) photometry of ≈83 million sources, covering 24,788 square degrees of the sky, wit... | matched photometric catalogs of galex uv sources with gaia dr2 and sdss dr14 databases (guvmatch) |
we study the kepler object kepler-432, an evolved star ascending the red giant branch. by deriving precise radial velocities from multi-epoch high-resolution spectra of kepler-432 taken with the cafe spectrograph at the 2.2 m telescope of calar alto observatory and the fies spectrograph at the nordic optical telescope ... | kepler-432 b: a massive warm jupiter in a 52-day eccentric orbit transiting a giant star |
while our current cosmological model places galaxy clusters at the nodes of a filament network (the cosmic web), we still struggle to detect these filaments at high redshifts. we perform a weak lensing study for a sample of 16 massive, medium-high redshift (0.4 <z< 0.9) galaxy clusters from the daft/fada survey, ... | weak lensing study of 16 daft/fada clusters: substructures and filaments |
we report the detection of an al ii line at 2669.155 å in 11 metal-poor stars, using ultraviolet spectra obtained with the space telescope imaging spectrograph on board the hubble space telescope. we derive al abundances from this line using a standard abundance analysis, assuming local thermodynamic equilibrium (lte).... | detection of al ii in the ultraviolet spectra of metal-poor stars: an empirical lte test of nlte aluminum abundance calculations |
with the 1.26 m national astronomical observatory-guangzhou university infrared/optical telescope (nagiot) at xinglong station of national astronomical observatories, chinese academy of sciences, we obtained 419 groups of simultaneous observations at g, r and i bands, for the first time, targeting quasar 3c 454.3 durin... | simultaneous optical g, r, i monitoring and idv periodic analysis for quasar 3c 454.3 |
two new high-resolution x-ray spectroscopy missions, xrism and athena, will observe deeper and with higher x-ray resolution than ever before possible. interpreting these new x-ray spectra will require understanding the impact that uncertainties on fundamental atomic quantities such as collisional cross sections, transi... | spectral implications of atomic uncertainties in optically thin hot plasmas |
we introduce the hott dust optical depth and temperature maps parameterizing thermal dust emission. such maps have revolutionized studies of the distribution of matter in molecular clouds and processes relevant to star formation, including virial stability. hott maps for a suite of fields, including the herschel gould ... | herschel optimized tau and temperature (hott) maps: uncertainty analysis and robust parameter extraction |
context. targeted spectroscopic exoplanet surveys face the challenge of maximizing their planet detection rates by means of careful planning. for a large planet survey, the number of possible observation combinations, i.e., the sequence of observations night after night, both in total time and amount of targets, is eno... | efficient scheduling of astronomical observations. application to the carmenes radial-velocity survey |
a simple millimeter wave and terahertz (thz) receiver scheme that uses subwavelength focusing of electromagnetic beam on the point-contact detector area with waveguide dimensions is studied. a detection system with such an optical coupling scheme is implemented, where the signal to be detected is coupled to a detector ... | improvement of a point-contact detector performance using the terajet effect initiated by photonics |
infrared detection and imaging are key enabling technologies for a vast number of applications, ranging from communication, to medicine and astronomy, and have recently attracted interest for their potential application in optical interconnects and quantum computing. nonetheless, infrared detection still constitutes th... | recent advances in infrared imagers: toward thermodynamic and quantum limits of photon sensitivity |
the ultraviolet (uv) extinction feature at 2175 å is ubiquitously observed in the galaxy but is rarely detected at high redshifts. here we report the spectroscopic detection of the 2175 å bump on the sightline to the γ-ray burst (grb) afterglow grb 180325a at z = 2.2486, the only unambiguous detection over the past 10 ... | the 2175 å extinction feature in the optical afterglow spectrum of grb 180325a at z = 2.25 |
intensity interferometry is a well known method in astronomy. recently, a related method called incoherent diffractive imaging (idi) was proposed to apply intensity correlations of x-ray fluorescence radiation to determine the 3d arrangement of the emitting atoms in a sample. here we discuss inherent sources of noise a... | photon statistics and signal to noise ratio for incoherent diffraction imaging |
we present a numerical and experimental study of the impact of phase errors on the performance of large, high-resolution arrayed waveguide gratings (awg) for applications in astronomy. we use a scalar diffraction model to study the transmission spectrum of an awg under random variations of the optical waveguide lengths... | performance limits of astronomical arrayed waveguide gratings on a silica platform |
we report on the accretion properties of low-mass stars in the lh 95 association within the large magellanic cloud. using noncontemporaneous wideband optical and narrowband hα photometry obtained with the hubble space telescope, we identify 245 low-mass pre-main-sequence (pms) candidates showing hα excess emission abov... | photometric determination of the mass accretion rates of pre-main-sequence stars. vi. the case of lh 95 in the large magellanic cloud |
multiple stellar populations are a widespread phenomenon among galactic globular clusters. even though the origin of the enriched material from which new generations of stars are produced remains unclear, it is likely that self-enrichment will be feasible only in clusters massive enough to retain this enriched material... | no evidence for multiple stellar populations in the low-mass galactic globular cluster e 3 |
context. based on their overwhelming dominance among associated fermi γ-ray catalogue sources, it is expected that a large fraction of the unidentified fermi objects are blazars. through crossmatching between the positions of unidentified γ-ray sources from the first fermi catalog of γ-ray sources emitting above 10 gev... | looking for blazars in a sample of unidentified high-energy emitting fermi sources |
the soft x-ray spectrometer on board hitomi, with the unprecedented resolving power of r ∼ 1250, allowed the detection of members of the fe xxv kα complex emission spectra from the center of the perseus cluster. in this paper, we introduce a novel method of measuring the column density using the optically thin (case a)... | x-ray spectroscopy in the microcalorimeter era. ii. a new diagnostic on column density from the case a to b transition in h- and he-like iron |
we present the nature of 50 hard x-ray emitting objects unveiled through an optical spectroscopy campaign performed at seven telescopes in the northern and southern hemispheres. these objects were detected with the burst alert telescope (bat) instrument onboard the swift satellite and listed as of unidentified nature i... | the nature of 50 palermo swift-bat hard x-ray objects through optical spectroscopy |
thorne-żytkow objects (tżos) are a class of stellar object comprised of a neutron star core surrounded by a large and diffuse envelope. their exterior appearance is identical to red supergiants; the distinctive electromagnetic signature of a tżo is a suite of unusual chemical abundance patterns, including excesses of l... | prospects for multimessenger observations of thorne-żytkow objects |
we present the first multiwavelength (near-infrared; 1.1-2.4 μm) imaging of hd 36546's debris disk, using the subaru coronagraphic extreme adaptive optics (scexao) system coupled with the coronagraphic high angular resolution imaging spectrograph (charis). as a 3-10 myr old star, hd 36546 presents a rare opportunity to... | multiband imaging of the hd 36546 debris disk: a refined view from scexao/charis |
during the new horizons spacecraft's encounter with pluto, the alice ultraviolet spectrograph conducted a series of observations that detected emissions from both the interplanetary medium (ipm) and pluto. in the direction of pluto, the ipm was found to be 133.4 ± 0.6 r at lyα, 0.24 ± 0.02 r at lyβ, and <0.10 r at h... | pluto's ultraviolet spectrum, surface reflectance, and airglow emissions |
theseus is a medium size space mission of the european space agency, currently under evaluation for a possible launch in 2032. its main objectives are to investigate the early universe through the observation of gamma-ray bursts and to study the gravitational waves electromagnetic counterparts and neutrino events. on t... | time domain astronomy with the theseus satellite |
the behavior of an adaptive optics (ao) system for ground-based high contrast imaging dictates the achievable contrast of the instrument. in conditions where the coherence time of the atmosphere is short compared with the speed of the ao system, the servo-lag error can become the dominant error term of the ao system. w... | predictive wavefront control on keck ii adaptive optics bench: on-sky coronagraphic results |
we present an analysis of survey observations of the trailing l5 jupiter trojan swarm using the wide-field hyper suprime-cam ccd camera on the 8.2 m subaru telescope. we detected 189 l5 trojans from our survey that covered about 15 deg2 of sky with a detection limit of mr= 24.1 mag, and selected an unbiased sample cons... | size distribution of small jupiter trojans in the l5 swarm |
in this study, we make use of a meso-scale numerical model to obtain the parameters of atmospheric optical turbulence at the ali observatory above the tibetan plateau. these parameters are essential for ground-based optical observations and some adaptive optics techniques. we present the characterization of the vertica... | modelling of atmospheric optical turbulence with the weather research and forecasting model at the ali observatory, tibet |
optical transition-edge sensors (tess) with high detection efficiency and energy resolution are attractive to applications such as quantum information, astronomy, and biological spectral imaging. in this work, we developed a titanium-based tes with an energy resolution of 0.24 ev at 1520 nm, i.e., a wavelength resoluti... | multi-color photon detection with a single superconducting transition-edge sensor |
two different silicate/water ice mixtures representing laboratory analogs of interstellar and circumstellar icy grains were produced in the laboratory. for the first time, optical constants, the real and imaginary parts of the complex refractive index, of such silicate/water ice mixtures were experimentally determined ... | low-temperature optical properties of interstellar and circumstellar icy silicate grain analogs in the mid-infrared spectral region |
the combination of visible and thermal data from the ground and astrophysics space missions is key to improving the scientific understanding of near-earth, main-belt, trojans, centaurs, and trans-neptunian objects. to get full information on a small sample of selected bodies we combine different methods and techniques:... | small bodies near and far (sbnaf): a benchmark study on physical and thermal properties of small bodies in the solar system |
on-sky tests conducted with an astro-comb using the potsdam multi-aperture spectrograph (pmas) at the 3.5 m calar alto telescope are reported. the proposed astro-comb approach is based on cascaded four-wave mixing between two lasers propagating through dispersion optimized nonlinear fibers. this approach allows for a l... | wavelength calibration with pmas at 3.5 m calar alto telescope using a tunable astro-comb |
intensity interferometry -- the correlation of spatially separated light intensities -- has historically been an important tool for precision optical astronomical observations. however, due to the extremely narrow field of view, its scope has been limited to studies of the morphology of very bright emission regions, pr... | astrometry with extended-path intensity correlation |
xinglong observatory of the national astronomical observatories, chinese academy of sciences (naoc), is one of the major optical observatories in china, which hosts nine optical telescopes including the large sky area multi-object fiber spectroscopic telescope (lamost) and the 2.16 m reflector. scientific research from... | astronomical observing conditions at xinglong observatory from 2007 to 2014 |
the survey of hi in extremely low-mass dwarfs is an on-going multi-wavelength program to characterize the gas, star formation, and evolution in gas-rich, very low-mass galaxies that populate the faint end of the galaxy luminosity function. the galaxies were selected from the first ∼10% of the hi arecibo legacy fast alf... | characterizing the star formation of the low-mass shield galaxies from hubble space telescope imaging |
we present an unprecedented spectroscopic survey of the ca ii triplet + o i for a sample of 14 luminous (-26≳ {{m}v}≳ -29), intermediate redshift (0.85 ≲ z ≲ 1.65) quasars. the infrared spectrometer and array camera spectrometer on the eso very large telescope allowed us to cover the ca ii near-infrared spectral region... | o i and ca ii observations in intermediate redshift quasars |
star formation in galaxies is a hierarchical process with a wide range of scales, from smaller clusters to larger stellar complexes. here, we present an ultra-violet imaging study of the nearby flocculent spiral galaxy ngc 7793, observed using the ultra-violet imaging telescope (uvit). we find that the disk scale lengt... | tracing young star-forming clumps in the nearby flocculent spiral galaxy ngc 7793 with uvit imaging |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.