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galactic science encompasses a wide range of subjects in the study of the milky way and magellanic clouds, from young stellar objects to x-ray binaries. mapping these populations, and exploring transient phenomena within them, are among the primary science goals of the vera c. rubin observatory's legacy survey of space... | lsst survey strategy in the galactic plane and magellanic clouds |
aims: with the ever-increasing survey speed of optical wide-field telescopes and the importance of discovering transients when they are still young, rapid and reliable source localization is paramount. we present autosourceid-light (asid-l), an innovative framework that uses computer vision techniques that can naturall... | autosourceid-light. fast optical source localization via u-net and laplacian of gaussian |
the winds of massive stars are important for their direct impact on the interstellar medium, and for their influence on the final state of a star prior to it exploding as a supernova. however, the dynamics of these winds is understood primarily via their illumination from a single central source. the doppler shift seen... | uv spectropolarimetry with polstar: massive star binary colliding winds |
an understanding of abundance and distribution of water vapor in the innermost region of protoplanetary disks is key to understanding the origin of habitable worlds and planetary systems. past observations have shown h2o to be abundant and a major carrier of elemental oxygen in disk surface layers that lie within the i... | water uv-shielding in the terrestrial planet-forming zone: implications for oxygen-18 isotope anomalies in {{h}}_{2}(18}{o) infrared emission and meteorites |
we report the discovery of two tess sub-neptunes orbiting the early m dwarf toi-904 (tic 261257684). both exoplanets, toi-904 b and c, were initially observed in tess sector 12 with twin sizes of ${2.426}_{-0.157}^{+0.163}$ and ${2.167}_{-0.118}^{+0.130}$ r ⊕, respectively. through observations in five additional secto... | separated twins or just siblings? a multiplanet system around an m dwarf including a cool sub-neptune |
context. ex lup is a well-studied t tauri star that represents the prototype of young eruptive stars known as exors. they are characterized by repetitive outbursts that are due to enhanced accretion from the circumstellar disk onto the star. in this paper, we analyze new adaptive optics imaging and spectroscopic observ... | the circumstellar environment of ex lupi: sphere and sinfoni views |
as the pupil size of ground-based telescopes increases, adaptive optics systems become more and more important for almost all astronomical observations. to test the performance of adaptive optics systems through simulation and with test bench experiments, we need to model the atmospheric turbulence with high fidelity. ... | simulation of atmospheric turbulence phase screen for large telescope and optical interferometer |
the compound eye of insects has numerous extraordinary optical performances, such as minimum chromatic aberration, wide-angle field of view, and high sensitivity to the incidence light. inspired by these unique performances, we present a novel artificial compound eye of photon sieves in this paper, where the photon sie... | an artificial compound eye of photon sieves |
the dynamics of a large stock of organic matter contained in deep sediments of marginal seas plays pivotal role in global carbon cycle, yet it is poorly constrained. here, dissolved organic matter (dom) in sediments was investigated for core sediment up to 240 meters deep in the east/japan sea. the upper downcore profi... | biological early diagenesis and insolation-paced paleoproductivity signified in deep core sediment organic matter |
the results of alignment and acceptance tests of the optics system of the 2.5-m telescope installed at the caucausus mountain observatory of the sternberg astronomical institute in 2013-2015 are reported. the optical elements of the ritchey-chrétien system of the telescope were manufactured by reosc (france). measureme... | analysis of the optics of the 2.5-m telescope of the sternberg astronomical institute |
arcus is a proposed explorer class soft x-ray grating spectrometer. it aims to explore cosmic feedback by mapping hot gases within and between galaxies and galaxy clusters and characterizing jets and winds from supermassive black holes and to investigate the dynamics of protoplanetary disks and stellar accretion. arcus... | x-ray performance of critical-angle transmission grating prototypes for the arcus mission |
isomers with the formula c3h2o have intrigued and puzzled astronomers and astrochemists for many years, with propynal and cyclopropenone, but not propadienone, known to be interstellar. however, there is a severe lack of laboratory spectra of the solid phases of these compounds with which to investigate their interstel... | propynal, an interstellar molecule with an exceptionally strong c ≡ c infrared band - laboratory infrared data and applications |
as part of the conceptual and preliminary design process of the chinese large telescope, we have spent the last several years measuring and statistically analyzing the atmospheric characteristics above the high ali observatory region, in the most western part of the tibetan plateau. this is the first article in a serie... | the characteristics at the ali observatory based on radiosonde observations |
for large-aperture optical/infrared astronomical telescopes, mirror coating is one of the most important maintenance technologies to ensure their stable and efficient operation. the quality of the coating directly affects the optical reflectivity of the mirror, and further the imaging quality and observation efficiency... | research progress of lamost sub-mirror coating |
we present results from speckle inteferometric observations of 15 visual binaries and one double-line spectroscopic binary, carried out with the hrcam speckle camera of the soar 4.1 m telescope. these systems were observed as a part of an on-going survey to characterize the binary population in the solar vicinity, out ... | orbits and masses of binaries from speckle interferometry at soar |
the advanced telescope for high energy astrophysics (athena) is the x-ray observatory mission selected by esa within its cosmic vision 2015-2025 programme to address the hot and energetic universe scientific theme. the eso-athena synergy team (east) has been tasked to single out the potential scientific synergies betwe... | eso-athena synergy white paper |
turbid water-based liquids are common scattering media within which imaging objects is challenging, since scattering particles of various origins and sizes may cause severe image degradation, resulting in poor object recovery and resolution. therefore, counteracting the nontrivial effects of light scattering is a prima... | experimental demonstration of imaging hidden objects in opaque liquid-based media by fusion of single-shot multiview polarized and unpolarized speckle images |
the hobby-eberly telescope dark energy experiment (hetdex) will utilize the visible integral-field replicable unit spectrograph (virus) to provide the first blind, wide-area, integral field spectroscopic survey. in this paper we provide an overview of the instrumentation and survey plans for hetdex and the expected con... | hetdex and virus: panoramic integral field spectroscopy with 35k fibers |
context. young field stars are hardly distinguishable from older ones because their space motion rapidly mixes them with the stellar population of the galactic plane. nevertheless, a careful target selection allows for young stars to be spotted throughout the sky.aims: we aim to identify additional sources associated w... | discovery of new members of the nearby young stellar association in cepheus |
we present a semi-empirical spectral classification scheme for normal b-type stars using near-infrared (nir) spectra (1.5-1.7 μm) from the sloan digital sky survey apache point observatory galaxy evolution experiment (apogee2)-n data release 14 (dr14) database. the main motivation for working with b-type stars is their... | spectral classification of b stars: the empirical sequence using sdss-iv/apogee near-ir data |
in the local universe, a large fraction of the baryon content is believed to exist as diffuse gas in filaments. while this gas is directly observable in x-ray emission around clusters of galaxies, it is primarily studied through its uv absorption. recently, x-ray observations of large-scale filaments connecting to the ... | cos observations of the cosmic web: a search for the cooler components of a hot, x-ray identified filament |
we have detected the submillimeter-wave fine-structure transition (3 p 1-3 p 0) of 13c, [13c i], in the gaseous debris disk of 49 ceti with the atacama large millimeter/submillimeter array (alma). recently, the [c i] 3 p 1-3 p 0 emission has been spatially resolved in this source with alma. in this data set, the f = 3/... | first detection of submillimeter-wave [13c i] 3 p 1-3 p 0 emission in a gaseous debris disk of 49 ceti with alma |
we report first results from an ongoing monitoring campaign to measure time delays between the six images of the quasar sdss j2222+2745, gravitationally lensed by a galaxy cluster. the time delay between a and b, the two most highly magnified images, is measured to be {τ }{{ab}}=47.7+/- 6.0 days (95% confidence interva... | time delay measurements for the cluster-lensed sextuple quasar sdss j2222+2745 |
visible-light long baseline interferometry holds the promise of advancing a number of important applications in fundamental astronomy, including the direct measurement of the angular diameters and oblateness of stars, and the direct measurement of the orbits of binary and multiple star systems. to advance, the field of... | vision: a six-telescope fiber-fed visible light beam combiner for the navy precision optical interferometer |
high-contrast imaging has afforded astronomers the opportunity to study light directly emitted by adolescent (tens of megayears) and "proto" (<10 myr) planets still undergoing formation. direct detection of these planets is enabled by empirical point-spread function (psf) modeling and removal algorithms. the computa... | the giant accreting protoplanet survey (gaplanets): optimization techniques for robust detections of protoplanets |
the supergiant high-mass x-ray binary igr j16318-4848 was the first source detected by the international gamma-ray astrophysics laboratory satellite in 2003 and distinguishes itself by its high intrinsic absorption and b[e] phenomenon. it is the perfect candidate to study both binary interaction and the environment of ... | optical and infrared study of the obscured b[e] supergiant high-mass x-ray binary igr j16318-4848 |
we outline polarization fringe predictions derived from an application of the berreman calculus for the daniel k. inouye solar telescope (dkist) retarder optics. the dkist retarder baseline design used six crystals, single-layer antireflection coatings, thick cover windows, and oil between all optical interfaces. this ... | polarization modeling and predictions for dkist part 2: application of the berreman calculus to spectral polarization fringes of beamsplitters and crystal retarders |
we present optical follow-up observation results of three binary black hole merger (bbh) events, gw190408_181802, gw190412, and gw190503_185404, which were detected by the advanced ligo and virgo gravitational wave (gw) detectors. electromagnetic (em) counterparts are generally not expected for bbh merger events. howev... | gecko optical follow-up observation of three binary black hole merger events: gw190408_181802, gw190412, and gw190503_185404 |
we present temperature maps of rs cvn star λ andromedae, reconstructed from interferometric data acquired in 2010 and 2011 by the michigan infra-red combiner instrument at the center for high angular resolution astronomy array. to constrain the stellar parameters required for this imaging task, we first modeled the sta... | dynamical surface imaging of λ andromedae |
the recent data on cosmic ray positron flux measured near the earth by the alpha magnetic spectrometer (ams-02) experiment extends to tev energy. the recently observed data by ams-02 clearly confirms that the positron flux rises with energy and shows a peak near a few hundred gev. this rising positron flux cannot be ex... | positron excess from cosmic ray interactions in galactic molecular clouds |
at a fraction of the total cost of an equivalent orbital mission, scientific balloon-borne platforms, operating above 99.7% of the earth's atmosphere, offer attractive, competitive, and effective observational capabilities—namely, space-like seeing, transmission, and backgrounds—which are well suited for modern astrono... | robust diffraction-limited near-infrared-to-near-ultraviolet wide-field imaging from stratospheric balloon-borne platforms—super-pressure balloon-borne imaging telescope performance |
we report spectroscopic redshift measurements for three bright submillimeter galaxies (smgs) near the goods-n field, each with scuba-2 850 μm fluxes >10 mjy, using the northern extended millimeter array (noema). our molecular line-scan observations of these sources, which occupy an ~7 arcmin2 area outside of the hub... | noema redshift measurements of extremely bright submillimeter galaxies near the goods-n |
the optical spectroscopic observations of asassn-18fv observed from 2018 march 24 to 2019 january 26 are presented. the optical spectra are obtained from mirranook, vainu bappu, and south african astronomical observatories. the spectra are dominated by the hydrogen balmer, fe ii, and o i lines with p-cygni profiles in ... | spectroscopic and geometrical evolution of the ejecta of the classical nova asassn-18fv |
the advent of new time domain surveys and the imminent increase in astronomical data expose the shortcomings of traditional time series analysis (such as power spectra analysis) in characterizing the abundantly varied, complex, and stochastic light curves of active galactic nuclei (agns). recent applications of novel m... | complex variability of kepler agn revealed by recurrence analysis |
in this contribution, we present the most recent progresses we obtained in the context of a long-term program we undertook since a few years towards the implementation of operational forecast systems (a) on top-class ground-based telescopes assisted by ao systems to support the flexible scheduling of observational scie... | new achievements in optical turbulence forecast systems in operational mode |
data lab is an open-access science platform developed and operated by the community and science data center (csdc) at nsf's national optical-infrared astronomy research laboratory (noirlab). it serves public photometric survey datasets, provides interactive and programmatic data access, and sql/adql query capabilities ... | data lab-a community science platform |
with the advent of high-cadence, all-sky automated surveys, supernovae (sne) are now discovered closer than ever to their dates of explosion. however, young premaximum light follow-up spectra of type ic sne (sne ic), probably arising from the most-stripped massive stars, remain rare despite their importance. in this le... | sn 2019ewu: a peculiar supernova with early strong carbon and weak oxygen features from a new sample of young sn ic spectra |
large area surveys will dominate the forthcoming decades of astronomy and their success requires characterizing thousands of discoveries through additional observations at higher spatial or spectral resolution, and at complementary cadences or periods. only the full automation of adaptive optics systems will enable hig... | automated adaptive optics |
the accurate estimation of photometric redshifts plays a crucial role in accomplishing science objectives of the large survey projects. template-fitting and machine learning are the two main types of methods applied currently. based on the training set obtained by cross-correlating the desi legacy imaging surveys dr9 g... | photometric redshift estimation of galaxies in the desi legacy imaging surveys |
habitability of an exoplanet is believed to be profoundly affected by activities of the host stars, although the related coronal mass ejections (cmes) are still rarely detected in solar-like and late-type stars. we here report an observational study on the flares of two m dwarfs triggered by the high-cadence survey per... | flaring-associated complex dynamics in two m dwarfs revealed by fast, time-resolved spectroscopy |
brightening of hen 3-860, previously classified as an hα emitter, was detected by the all-sky automated survey for supernovae (asas-sn) survey at the end of the year 2016. we have obtained the first spectroscopic observations of the transient and supplemented them with photometric data from the digital access to a sky ... | hen 3-860: new southern eclipsing symbiotic star observed in the outburst |
deep generative models including generative adversarial networks (gans) are powerful unsupervised tools in learning the distributions of data sets. building a simple gan architecture in pytorch and training on the candels data set, we generate galaxy images with the hubble space telescope (hst) resolution starting from... | deblending galaxies with generative adversarial networks |
methanol (ch3oh) is an abundant interstellar species and is known to be an important precursor of various interstellar complex organic molecules. among the methanol isotopologues, ch2doh is one of the most abundant isotopologues and it is often used to study the deuterium fractionation of ch3oh in interstellar medium. ... | laboratory measurement of millimeter-wave transitions of 13ch2doh for astronomical use |
we demonstrate a broad, flat, visible supercontinuum spectrum that is generated by a dispersion-engineered tapered photonic crystal fiber pumped by a 1 ghz repetition rate turn-key ti:sapphire laser outputting $\sim$ 30 fs pulses at 800 nm. at a pulse energy of 100 pj, we obtain an output spectrum that is flat to withi... | visible-spanning flat supercontinuum for astronomical applications |
gravitational waves are a prediction of einstein's general relativity theory. in autumn 2017, the laser interferometer gravitational-wave observatory (ligo; https://www.ligo.caltech.edu/) experiment reported the first detection of gravitational waves in addition to electromagnetic radiation from the collision of two ne... | a telescope for lisa – the laser interferometer space antenna |
astronomical seeing is important for monitoring the atmospheric environment, observation scheduling and management, and selecting astronomical sites. this study first attempts to establish a near-global astronomical seeing map by employing the fifth european centre for medium-range weather forecasts reanalysis (era5) d... | investigation of the global spatio-temporal characteristics of astronomical seeing |
we report the results of a long-term spectroscopic monitoring of the fs cma type object mwc 728. we found that it is a binary system with a b5 ve ({t}{eff} = 14,000 ± 1000 k) primary and a g8 iii type ({t}{eff} ∼ 5000 k) secondary. absorption line positions of the secondary vary, with a semi-amplitude of ∼20 km s-1 and... | toward understanding the b[e] phenomenon. v. nature and spectral variations of the mwc 728 binary system. |
telescopes with a wide field of view (greater than 1°) and small apertures (less than 2 m) are workhorses for observations such as sky surveys and fast-moving object detection, and play an important role in time-domain astronomy. however, images captured by these telescopes are contaminated by optical system aberration... | blind deconvolution with principal components analysis for wide-field and small-aperture telescopes |
hiz-gundam is a future satellite mission which will lead the time-domain astronomy and the multi-messenger astronomy through observations of high-energy transient phenomena. a mission concept of hiz-gundam was approved by isas/jaxa, and it is one of the future satellite candidates of jaxa's medium-class mission. we are... | high-redshift gamma-ray burst for unraveling the dark ages mission: hiz-gundam |
context. magnetic cataclysmic variables are close binary systems containing a strongly magnetized white dwarf that accretes matter coming from an m-dwarf companion. the high magnetic field strength leads to the formation of an accretion column instead of an accretion disk. high-energy radiation coming from those object... | quasi-periodic oscillations in accreting magnetic white dwarfs. ii. the asset of numerical modelling for interpreting observations |
the nuclear symmetry energy plays a key role in determining the equation of state (eos) of dense, neutron-rich matter, which connects the atomic nuclei with the hot and dense matter in universe, thus has been the subject of intense investigations in laboratory experiments, astronomy observations and theories. various p... | constraining equation of state of nuclear matter by charge-changing cross section measurements of mirror nuclei |
einstein's general theory of relativity not only revolutionized human understanding of the universe, but also brought many gravitational applications in large scale, such as gravitational-wave astronomy, gravitational lensing, and the operation of the global positioning system. however, it still remains a challenge to ... | gravitationally sensitive structured x-ray optics using nuclear resonances |
phase-sensitive coherent imaging exploits changes in the phases of backscattered light to observe tiny alterations of scattering structures or variations of the refractive index. but moving scatterers or a fluctuating refractive index decorrelate the phases and speckle patterns in the images. it is generally believed t... | phase-sensitive interferometry of decorrelated speckle patterns |
space debris detection is important for space asset protection and space situational awareness. the current environment of man-made satellites and space debris objects in earth orbits increases rapidly, so does the probability of collision between them. in this paper, we propose a space debris detection method based on... | a space debris detection and tracking method for wide-field surveillance |
we report our photometric and spectroscopic follow-up observations of the superoutbursts of three dwarf novae (dne; gwac 180415a, gwac 181017a, and gwac 181211a) identified independently by the ground wide-angle cameras system, one of the ground-based instruments of the china-france svom mission. based on a combination... | photometric and spectroscopic studies of superoutbursts of three dwarf novae independently identified by the svom/gwac system in 2018 |
aims: our goal is to characterise the dependence of the optical mass-to-light ratio on galaxy colour up to z = 1.5, expanding the redshift range explored in previous work.methods: from the redshifts, stellar masses, and rest-frame luminosities of the alhambra multi-filter survey, we derive the mass-to-light ratio versu... | the alhambra survey: tight dependence of the optical mass-to-light ratio on galaxy colour up to z = 1.5 |
we have mapped the ngc 2023 reflection nebula in [c ii] and co(11-10) with the heterodyne receiver great on sofia and obtained slightly smaller maps in 13co(3-2), co(3-2), co(4-3), co(6-5), and co(7-6) with apex in chile. we use these data to probe the morphology, kinematics, and physical conditions of the c ii region,... | high spectral and spatial resolution observations of the pdr emission in the ngc 2023 reflection nebula with sofia and apex |
we present eldar, a new method that exploits the potential of medium- and narrow-band filter surveys to securely identify active galactic nuclei (agn) and determine their redshifts. our methodology improves on traditional approaches by looking for agn emission lines expected to be identified against the continuum, than... | eldar, a new method to identify agn in multi-filter surveys: the alhambra test case |
the emerging microresonator-based frequency combs revolutionize a broad range of applications from optical communications to astronomical calibration. despite of their significant merits, low energy efficiency and the lack of all-optical dynamical control severely hinder the transfer of microcomb system to real-world a... | gain-assisted chiral soliton microcombs |
in this contribution i review how optical interferometry has contributed to shaping our understanding of the class of herbig ae/be stars and of their associated circumstellar disks. i discuss the evidence for an optically-thin cavity in the inner few astronomical units (au) and a "puffed-up rim" near the dust sublimati... | the interferometric view of herbig ae/be stars |
motivated by the potential of nondiffraction limited, real-time computational image sharpening with neural networks in astronomical telescopes, we studied wavefront sensing with convolutional neural networks based on a pair of in-focus and out-of-focus point spread functions. by simulation, we generated a large dataset... | image-based wavefront sensing for astronomy using neural networks |
future astronomical instruments will require sub-kelvin detector temperatures to obtain high sensitivity. in many cases large arrays of detectors will be used, and the associated cooling systems will need performance surpassing the limits of present technologies. nasa is developing a compact cooling system that will li... | development of a space-flight adr providing continuous cooling at 50 mk with heat rejection at 10 k |
stable narrow-linewidth lasers generated by self-injection locking systems have revolutionized applications from optical frequency metrology to astronomy. however, the dynamics for the self-injection locking system are intrinsically intertwined with thermal effects, which can generate a nonnegligible resonance drift in... | influence of thermal effects in microresonators on the locking range in self-injection locking of laser diodes |
we use deep near-ir photometry of the vista variables in the vía láctea (vvv) survey and deep decam plane survey (decaps) optical photometry to confirm the physical reality of the candidate globular cluster (gc) minni 22, which is located in the galactic bulge. this object, which was detected as a high density region i... | confirmation of a new metal-poor globular cluster in the galactic bulge |
multi-pixel fast silicon detectors represent the enabling technology for the next generation of space-borne experiments devoted to high-resolution spectral-timing studies of low-flux compact cosmic sources. several imaging detectors based on frame-integration have been developed as focal plane devices for x-ray space-b... | characterization of a novel pixelated silicon drift detector (pixdd) for high-throughput x-ray astrophysics |
modern ground-based telescopes like the planned extremely large telescope (elt) depend heavily on adaptive optics (ao) systems to correct for atmospheric turbulence. even though ao correction is used, the quality of astronomical images still is degraded due to the time delay stemming from the wavefront sensor integrati... | point spread function reconstruction for single-conjugate adaptive optics on extremely large telescopes |
we report the discovery of a mid-infrared (mir) flare using wide field infrared survey explorer data in the center of the nearby seyfert 1.9 galaxy mcg-02-04-026. the mir flare began in the first half of 2014, peaked around the end of 2015, and faded in 2017. during these years, energy of more than 7 × 1050 erg was rel... | a mid-infrared flare in the active galaxy mcg-02-04-026: dust echo of a nuclear transient event |
we report on a common fragment ion formed during the electron-ionization-induced fragmentation of three different three-ring polycyclic aromatic hydrocarbons (pahs), fluorene (c13h10), 9,10-dihydrophenanthrene (c14h12), and 9,10-dihydroanthracene (c14h12). the infrared spectra of the mass-isolated product ions with m/z... | breakdown products of gaseous polycyclic aromatic hydrocarbons investigated with infrared ion spectroscopy |
we present an application of a particular machine-learning method (boosted decision trees, bdts using adaboost) to separate stars and galaxies in photometric images using their catalog characteristics. bdts are a well established machine learning technique used for classification purposes. they have been widely used sp... | effect of training characteristics on object classification: an application using boosted decision trees |
exploring the use of single-mode fibers (smfs) in high precision doppler spectrometers has become increasingly attractive since the advent of diffraction-limited adaptive optics systems on large-aperture telescopes. spectrometers fed with these fibers can be made significantly smaller than typical “seeing-limited” inst... | "modal noise" in single-mode fibers: a cautionary note for high precision radial velocity instruments |
the array camera for optical to near-ir spectrophotometry, or arcons, is a camera based on microwave kinetic inductance detectors (mkids), a new technology that has the potential for broad application in astronomy. using an array of mkids, the instrument is able to produce time-resolved imaging and low-resolution spect... | the arcons pipeline: data reduction for mkid arrays |
triple-active galactic nucleus (agn) systems are expected to be the result of the hierarchical model of galaxy formation. since there are very few of them confirmed as such, we present the results of a new study of the triple agn candidate sdss j102700.40+174900.8 (center nucleus) through observations with the gtc-mega... | 3d spectroscopy with gtc-megara of the triple agn candidate in sdss j102700.40+174900.8 |
in this paper we introduce the terzina telescope as a part of the nuses space mission. this telescope aims to detect ultra high energy cosmic rays (uhecrs) through the cherenkov light emission from the extensive air showers (eas) that they create in the earth's atmosphere. the cherenkov photons are aligned along the sh... | terzina on board nuses: a pathfinder for eas cherenkov light detection from space |
observations across the electromagnetic spectrum of radiative processes involving interstellar dust-emission, absorption, and scattering-are used to constrain the parameters of dust models and more directly to aid in foreground removal of dust for extragalactic and cosmological observations. dust models can benefit fro... | joint modelling of dust scattering and thermal emission: the spider complex |
context. variability has proven to be a powerful tool to detect active galactic nuclei (agn) in multi-epoch surveys. the new-generation facilities expected to become operational in the next few years will mark a new era in time-domain astronomy and their wide-field multi-epoch campaigns will favor extensive variability... | extending the variability selection of active galactic nuclei in the w-cdf-s and servs/swire region |
time-correlated single photon counting (tcspc) and time tagging of individual photon detections are powerful tools in many quantum optical experiments and other areas of applied physics. using tcspc, e.g., for the purpose of fluorescence lifetime measurements, is often limited in speed due to dead-time losses and pileu... | photon arrival time tagging with many channels, sub-nanosecond deadtime, very high throughput, and fiber optic remote synchronization |
context. transit events of extrasolar planets offer the opportunity to study the composition of their atmospheres. previous work on transmission spectroscopy of the close-in gas giant (tres)-3 b revealed an increase in absorption towards blue wavelengths of very large amplitude in terms of atmospheric pressure scale he... | transmission spectroscopy of the hot jupiter tres-3 b: disproof of an overly large rayleigh-like feature |
ground-based optical astronomical observations supported by or in the vicinity of laser guide-star systems can be contaminated by raman-scattered laser photons. anticipating, alleviating, and correcting for the impact of this self-inflicted contamination requires a detailed knowledge of the pure-rotational and rotation... | pure-rotational and rotational-vibrational raman spectrum of the atmosphere at an altitude of 23 km |
we present interferometric observations of 25 spectral type-b stars that were made with the precision astronomical visible observations and the classic interferometry with multiple baselines beam combiners at the center for high angular resolution astronomy array (chara). the observations provide the angular sizes of t... | angular sizes, radii, and effective temperatures of b-type stars from optical interferometry with the chara array |
dust particles play a major role in the formation, evolution and chemistry of interstellar clouds, stars, and planetary systems. commonly identified forms include amorphous and crystalline carbon-rich particles and silicates. also present in many astrophysical environments are polycyclic aromatic hydrocarbons (pahs), d... | graphene oxide nanoparticles in the interstellar medium |
maat is proposed as a visitor mirror-slicer optical system that will allow the osiris spectrograph on the 10.4-m gran telescopio canarias (gtc) the capability to perform integral field spectroscopy (ifs) over a seeing-limited fov 14.20''x10'' with a slice width of 0.303''. maat@gtc will enhance the resolution power of ... | white paper on maat@gtc |
we report the discovery and characterization of seven transiting exoplanets from the hatnet survey. the planets, which are hot jupiters and saturns transiting bright sun-like stars, include: hat-p-58b (with mass mp = 0.37 mj, radius rp = 1.33 rj, and orbital period p = 4.0138 days), hat-p-59b (mp = 1.54 mj, rp = 1.12 r... | hat-p-58b-hat-p-64b: seven planets transiting bright stars |
the einstein probe (ep) is an x-ray astronomical mission mainly devoting to time-domain astronomy. there are two main scientific payloads onboard ep, the wide field x-ray telescope (wxt) based on the lobster eye optics and the follow-up x-ray telescope (fxt). fxt contains two wolter-1 mirrors with a pnccd detector on e... | status of the follow-up x-ray telescope onboard the einstein probe satellite |
we present a new method to measure the vertical aerosol optical depth (vaod) during clear nights using a wide-field imager—a ccd camera with a photographic lens on an equatorial mount. a series of 30 s exposures taken at different altitudes above the horizon can be used to measure the vaod with a precision better than ... | a new method for aerosol measurement using wide-field photometry |
context. the coeval stars of young open clusters provide insights into the formation of the rotation-activity relationship that elude studies of multi-age field populations.aims: we measure the chromospheric activity of cool stars in the 300 myr old open cluster ngc 3532 in concert with their rotation periods to study ... | a detailed understanding of the rotation-activity relationship using the 300 myr old open cluster ngc 3532 |
knowledge of the night sky radiance over a large region may be valuable information for identifying sites suitable for astronomical observations or for assessing the impact of artificial light at night on ecosystems. measuring the sky radiance can be a complex endeavour, depending on the desired temporal and spatial re... | point spread functions for mapping artificial night sky luminance over large territories |
frequency combs with mode spacing of 10-20 ghz are critical for increasingly important applications such as astronomical spectrograph calibration, high-speed dual-comb spectroscopy, and low-noise microwave generation. while electro-optic modulators and microresonators can provide narrowband comb sources at this repetit... | 20 ghz fiber-integrated femtosecond pulse and supercontinuum generation with a resonant electro-optic frequency comb |
ngc 1313 x-1 is a mysterious ultraluminous x-ray (ulx) source whose x-ray-powering mechanism and bubble-like structure surrounding the source are topics of intense study. here, we perform an x-ray spectroscopic study of the source using joint xmm-newton and nustar observations taken during 2012-2017. the combined spect... | broadband x-ray spectral analysis of the ulx ngc 1313 x-1 using jetcaf: origin of the ulx bubble |
winered is a newly built high-efficiency (throughput$ > 25-30\%$) and high-resolution spectrograph customized for short nir bands at 0.9-1.35 ${\rm \mu}$m. winered is equipped with ambient temperature optics and a cryogenic camera using a 1.7 ${\rm \mu}$m cut-off hgcdte hawaii-2rg array detector. winered has two gra... | a warm near-infrared high-resolution spectrograph with very high throughput (winered) |
we present the first polarimetric detection of the inner disk component around the pre-main-sequence b9.5 star hd 141569a. gemini planet imager h-band (1.65 μm) polarimetric differential imaging reveals the highest signal-to-noise ratio detection of this ring yet attained and traces structure inward to 0.″25 (28 au at ... | imaging the 44 au kuiper belt analog debris ring around hd 141569a with gpi polarimetry |
crts j084133.15+200525.8 is an optically bright quasar at z = 2.345 that has shown extreme spectral variability over the past decade. photometrically, the source had a visual magnitude of v ∼ 17.3 between 2002 and 2008. then, over the following five years, the source slowly brightened by approximately one magnitude, to... | extreme variability in a broad absorption line quasar |
machine learning techniques have been successfully used to classify variable stars on widely studied astronomical surveys. these data sets have been available to astronomers long enough, thus allowing them to perform deep analysis over several variable sources and generating useful catalogs with identified variable sta... | automatic survey-invariant classification of variable stars |
while it is well documented that the hawaiian hot spot has shifted southward relative to the spin axis since the formation of some of the emperor seamounts, the paleolatitude of the hot spot during the formation of the hawaiian chain is poorly known. to better determine the latter, here we estimate the location of the ... | pacific plate apparent polar wander, hot spot fixity, and true polar wander during the formation of the hawaiian island and seamount chain from an analysis of the skewness of magnetic anomaly 20r (44 ma) |
the imaging x-ray polarimetry explorer (ixpe) will expand the information space for study of cosmic sources, by adding linear polarization to the properties (time, energy, and position) observed in x-ray astronomy. selected in 2017 january as a nasa astrophysics small explorer (smex) mission, ixpe will be launched into... | the imaging x-ray polarimetry explorer (ixpe): technical overview |
we discuss the implementation and performance of an adaptive optics (ao) system that uses two cascaded deformable phase plates (dpps), which are transparent optofluidic phase modulators, mimicking the common woofer/tweeter-type astronomical ao systems. one of the dpps has 25 electrodes forming a keystone pattern best s... | cascading optofluidic phase modulators for performance enhancement in refractive adaptive optics |
in this paper, q-switched pulses were generated for the first time in a holmium-doped fiber laser (hdfl) incorporating a niobium carbide-polyvinyl alcohol (nb2c-pva) film-based saturable absorber (sa). at a pump power of 285.7 mw, q-switched pulses were observed with a repetition rate of 20.5 khz and a minimum pulse wi... | 2. 08 μm q-switched holmium fiber laser using niobium carbide-polyvinyl alcohol (nb2c-pva) as a saturable absorber |
electromagnetic transients known as kilonovae (kn), are among the photonic messengers released in the post-merger phase of compact binary objects, for example, binary neutron stars, and they have been recently observed as the electromagnetic counterpart of related gravitational-wave (gw) events. detection of the kn sig... | experimental and numerical investigation of magneto-plasma optical properties toward measurements of opacity relevant for compact binary objects |
the giant segmented mirror telescopes (gsmts) including the giant magellan telescope (gmt), the thirty meter telescope (tmt), and the european extremely large telescope (e-elt), all have extreme adaptive optics (exao) instruments planned that will use pyramid wavefront sensors (pwfs). the exao instruments all have comm... | three-sided pyramid wavefront sensor, part 1: simulations and analysis for astronomical adaptive optics |
we have been developing kyoto's x-ray astronomy soi pixel sensors, called "xrpix", aiming to extend the frontiers of x-ray astronomy with the wide-band imaging spectroscopy in the 0.5-40 kev band. a dead layer on the x-ray incident surface should ideally be as thin as possible to achieve a high sensitivity below 1 kev,... | the first back-side illuminated types of kyoto's x-ray astronomy soipix |
visibility of a new crescent moon is crucial for muslims when declaring the beginning of the islamic calendar. for many years, astronomers had observed the visibility of the new crescent moon using various techniques, such as the naked eye and optical instruments. in line with technological developments, astronomers ha... | detection of a new crescent moon using the maximally stable extremal regions (mser) technique |
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