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astronomical precision spectroscopy underpins searches for life beyond earth, direct observation of the expanding universe and constraining the potential variability of physical constants across cosmological scales. laser frequency combs can provide the critically required accurate and precise calibration to the astron... | ultraviolet astronomical spectrograph calibration with laser frequency combs from nanophotonic waveguides |
dense circumstellar material (csm) is thought to play an important role in observed luminous optical transients: if such csm is shocked, e.g., by ejecta expelled from the progenitor during core-collapse, then radiation produced by the shock-heated csm can power bright uv/optical emission. if the initial csm has an "out... | analytic light curves of dense csm shock breakout and cooling |
that the speed of light in vacuum is constant is a cornerstone of modern physics. however, recent experiments have shown that when the light field is confined in the transverse plane, the observed propagation speed of the light is reduced. this effect is a consequence of the transverse structure which reduces the compo... | the propagation speed of optical speckle |
atomic oxygen is a main component of the mesosphere and lower thermosphere of the earth, where it governs photochemistry and energy balance and is a tracer for dynamical motions. however, its concentration is extremely difficult to measure with remote sensing techniques since atomic oxygen has few optically active tran... | direct measurements of atomic oxygen in the mesosphere and lower thermosphere using terahertz heterodyne spectroscopy |
a1689-zd1 is one of the most distant galaxies, discovered with the aid of gravitational lensing, providing us with an important opportunity to study galaxy formation in the very early universe. in this study, we report the detection of [c ii]158 μm and [o iii]88 μm emission lines of a1689-zd1 in the atacama large milli... | alma detections of [o iii] and [c ii] emission lines from a1689-zd1 at z = 7.13 |
(abridged) this is the maunakea spectroscopic explorer 2018 book. it is intended as a concise reference guide to all aspects of the scientific and technical design of mse, for the international astronomy and engineering communities, and related agencies. the current version is a status report of mse's science goals and... | the maunakea spectroscopic explorer book 2018 |
in addition to astro-meteorological parameters, such as seeing, coherence time, and isoplanatic angle, the vertical profile of the earth's atmospheric turbulence strength and velocity is important for instrument design, performance validation and monitoring, and observation scheduling and management. here we compare th... | atmospheric turbulence forecasting with a general circulation model for cerro paranal |
we presented 15 new t dwarfs that were selected from ukirt infrared deep sky survey, visible and infrared survey telescope for astronomy , and wide-field infrared survey explorer surveys, and confirmed with optical to near-infrared spectra obtained with the very large telescope and the gran telescopio canarias. one of ... | primeval very low-mass stars and brown dwarfs - vi. population properties of metal-poor degenerate brown dwarfs |
context. galactic globular clusters (gcs) are now known to host multiple populations displaying particular abundance variations. the different populations within a gc can be well distinguished following their position in the pseudo two-colors diagrams, also referred to as "chromosome maps". these maps are constructed u... | a stellar census in globular clusters with muse: multiple populations chemistry in ngc 2808 |
the development of high-resolution, large-baseline optical interferometers would revolutionize astronomical imaging. however, classical techniques are hindered by physical limitations including loss, noise, and the fact that the received light is generally quantum in nature. we show how to overcome these issues using q... | imaging stars with quantum error correction |
bismuth (bi)-doped aluminosilicate, phosphosilicate, germanosilicate and high (⩾50 mol%) germanosilicate fibers have shown luminescence around 1.15 μm, 1.3 μm, 1.45 μm and 1.7 μm, respectively. bi-doped fibers have paved the way for developing optical amplifiers and fiber lasers in the wavelength region of 1150-1500 nm... | (invited) bi-doped optical fibers and fiber amplifiers |
localizing sources on the sky is crucial for realizing the full potential of gravitational waves for astronomy, astrophysics, and cosmology. we show that the midfrequency band, roughly 0.03 to 10 hz, has significant potential for angular localization. the angular location is measured through the changing doppler shift ... | localizing gravitational wave sources with single-baseline atom interferometers |
detection of electromagnetic signals for applications such as health, product quality monitoring or astronomy requires highly responsive and wavelength selective devices. photomultiplication-type organic photodetectors have been shown to achieve high quantum efficiencies mainly in the visible range. much less research ... | enhancing sub-bandgap external quantum efficiency by photomultiplication for narrowband organic near-infrared photodetectors |
sn 2017dio shows both spectral characteristics of a type-ic supernova (sn) and signs of a hydrogen-rich circumstellar medium (csm). prominent, narrow emission lines of h and he are superposed on the continuum. subsequent evolution revealed that the sn ejecta are interacting with the csm. the initial sn ic identificatio... | sn 2017dio: a type-ic supernova exploding in a hydrogen-rich circumstellar medium |
the sensitivity of the the pyramid wavefront sensor (pywfs) has made it a popular choice for astronomical adaptive optics (aao) systems, and it is at its most sensitive when it is used without modulation of the input beam. in non-modulated mode, the device is highly nonlinear. hence, all pywfs implementations on curren... | efficient, nonlinear phase estimation with the nonmodulated pyramid wavefront sensor |
our ability to study the properties of the interstellar medium in the earliest galaxies will rely on emission-line diagnostics at rest-frame ultraviolet (uv) wavelengths. in this work, we identify metallicity-sensitive diagnostics using uv emission lines. we compare uv-derived metallicities with standard, well-establis... | a comparison of uv and optical metallicities in star-forming galaxies |
we present the analysis of several observations of the black hole binary gx 339-4 during its bright intermediate states from two different outbursts (2002 and 2004), as observed by the rxte/proportional counter array. we perform a consistent study of its reflection spectrum by employing the relxill family of relativist... | evolution of the accretion disk-corona during the bright hard-to-soft state transition: a reflection spectroscopic study with gx 339-4 |
the millimetre astronomy legacy team 90 ghz survey aims to characterise the physical and chemical evolution of high-mass clumps. recently completed, it mapped 90 ghz line emission towards 3 246 high-mass clumps identified from the atlasgal 870 μm galactic plane survey. by utilising the broad frequency coverage of the m... | molecular line emission towards high-mass clumps: the malt90 catalogue |
detections of the tidal disruption flares (tdfs) of stars by supermassive black holes (smbhs) are rapidly accumulating as optical surveys improve. these detections may provide constraints on smbh demographics, stellar dynamics, and stellar evolution in galaxies. to maximize this scientific impact, we require a better u... | forward modeling populations of flares from tidal disruptions of stars by supermassive black holes |
historically, fu orionis-type stars are low-mass, pre-main-sequence stars. the members of this class experience powerful accretion outbursts and remain in an enhanced accretion state for decades or centuries. v1515 cyg, a classical fuor, started brightening in the 1940s and reached its peak brightness in the late 1970s... | a multi-epoch, multiwavelength study of the classical fuor v1515 cyg approaching quiescence |
imaging point sources with low angular separation near or below the rayleigh criterion is important in astronomy, e.g., in the search for habitable exoplanets near stars. however, the measurement time required to resolve stars in the sub-rayleigh region via traditional direct imaging is usually prohibitive. here we pro... | quantum-accelerated imaging of n stars |
we develop a new retrieval scheme for obtaining two-dimensional surface maps of exoplanets from scattered light curves. in our scheme, the combination of the l1-norm and total squared variation, which is one of the techniques used in sparse modeling, is adopted to find the optimal map. we apply the new method to simula... | global mapping of an exo-earth using sparse modeling |
m33 x-7 is the only known eclipsing black hole high mass x-ray binary. the system is reported to contain a very massive o supergiant donor and a massive black hole in a short orbit. the high x-ray luminosity and its location in the metal-poor galaxy m33 make it a unique laboratory for studying the winds of metal-poor d... | phase-resolved spectroscopic analysis of the eclipsing black hole x-ray binary m33 x-7: system properties, accretion, and evolution |
based on recent hubble space telescope (hst) observations in the far-uv and ground-based observations in optical bands, pavlov and colleagues have revealed a thermal component in the spectrum of the old pulsar b0950+08 (spin-down age 17.5 myr) and estimated a neutron star (ns) surface temperature of (1-3) × 105 k. our ... | thermal and nonthermal emission in the optical-uv spectrum of psr b0950+08 |
we invoke a gaussian mixture model (gmm) to jointly analyse two traditional emission-line classification schemes of galaxy ionization sources: the baldwin-phillips-terlevich (bpt) and wh α versus [n ii]/h α (whan) diagrams, using spectroscopic data from the sloan digital sky survey data release 7 and seagal/starlight d... | a probabilistic approach to emission-line galaxy classification |
planet yield calculations may be used to inform the target selection strategy and science operations of space observatories. forthcoming and proposed nasa missions, such as the wide-field infrared survey telescope, the habitable exoplanet imaging mission, and the large uv/optical/ir surveyor, are expected to be equippe... | joint radial velocity and direct imaging planet yield calculations. i. self-consistent planet populations |
context. the diffusion of adaptive optics systems in astronomical instrumentation for large ground-based telescopes is rapidly increasing and the pyramid wavefront sensor is replacing the shack-hartmann as the standard solution for single conjugate adaptive optics systems. the pyramid wavefront sensor is typically used... | non-modulated pyramid wavefront sensor. use in sensing and correcting atmospheric turbulence |
tigre (telescopio internacional de guanajuato robótico espectroscópico) has been operating in fully robotic mode in the la luz observatory (guanajuato, mexico) since the end of 2013. with its sole instrument, heros, an échelle spectrograph with a spectral resolution r ∼20,000, tigre has collected more than 48,000 spect... | eight years of tigre robotic spectroscopy: operational experience and selected scientific results |
the virgo detector, based at the ego (european gravitational observatory) and located in cascina (pisa), played a significant role in the development of the gravitational-wave astronomy. from its first scientific run in 2007, the virgo detector has constantly been upgraded over the years; since 2017, with the advanced ... | advanced virgo: status of the detector, latest results and future prospects |
optical observations represent a passive method for space debris tracking and monitoring. although being constrained to limited time intervals, e.g. when the target is in sunlight and the observatory is in darkness, a debris observatory network distributed over multiple locations can improve the observational interval ... | sapienza space debris observatory network (sson): a high coverage infrastructure for space debris monitoring |
optical turbulence greatly impacts the range and quality of astronomical observations. advanced knowledge of the expected atmospheric optical turbulence provides important guidance that helps astronomers decide which instrument to schedule and enables them to optimize the adaptive optics technology that improves image ... | forecasting seeing for the maunakea observatories |
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... | esa voyage 2050 white paper -- faint objects in motion: the new frontier of high precision astrometry |
we present the first resolved near-infrared imagery of the transition disk oph irs 48 (wly 2-48), which was recently observed with alma to have a strongly asymmetric submillimeter flux distribution. h-band polarized intensity images show a ~60 au radius scattered light cavity with two pronounced arcs of emission, one f... | seeds adaptive optics imaging of the asymmetric transition disk oph irs 48 in scattered light |
we present the star formation history (sfh) of the extremely metal-poor dwarf galaxy ddo 68, based on our photometry with the advanced camera for surveys. with a metallicity of only 12+{log}({{o}}/{{h}})=7.15 and a very isolated location, ddo 68 is one of the most metal-poor galaxies known. it has been argued that ddo ... | stellar populations and star formation history of the metal-poor dwarf galaxy ddo 68 |
we present spitzer/infrared array camera observations of dust formation from six extragalactic carbon-rich wolf-rayet (wc) binary candidates in low-metallicity (z ≲ 0.65 z⊙) environments using multiepoch mid-infrared (ir) imaging data from the spitzer infrared intensive transients survey (spirits). optical follow-up sp... | revealing efficient dust formation at low metallicity in extragalactic carbon-rich wolf-rayet binaries |
understanding common envelope (ce) evolution is an outstanding problem in binary evolution. although the ce phase is not driven by gravitational wave (gw) emission, the inspiraling binary emits gws that passively trace ce dynamics. detecting this gw signal would provide direct insight into gas-driven physics. even a no... | prospects of gravitational wave detections from common envelope evolution with lisa |
the efficiency of the management of top-class ground-based astronomical facilities supported by adaptive optics (ao) relies on our ability to forecast the optical turbulence (ot) and a set of relevant atmospheric parameters. indeed, in spite of the fact that the ao is able to achieve, at present, excellent levels of wa... | filtering techniques to enhance optical turbulence forecast performances at short time-scales |
extreme adaptive optics (ao) systems are now in operation across the globe. these systems, capable of high order wavefront correction, deliver strehl ratios of ∼ 90 % in the near-infrared. originally intended for the direct imaging of exoplanets, these systems are often equipped with advanced coronagraphs that suppress... | enhancing stellar spectroscopy with extreme adaptive optics and photonics |
we consider wiyn/hydra spectra of 329 photometric candidate members of the 420 myr old open cluster m48 and report lithium detections or upper limits for 234 members and likely members. the 171 single members define a number of notable li-mass trends, some delineated even more clearly than in hyades/praesepe: the giant... | wiyn open cluster study 89. m48 (ngc 2548) 2: lithium abundances in the 420 myr open cluster m48 from giants through k dwarfs |
refractive optical elements are widely used in millimeter and sub-millimeter astronomical telescopes. high resistivity silicon is an excellent material for dielectric lenses given its low loss-tangent, high thermal conductivity and high index of refraction. the high index of refraction of silicon causes a large fresnel... | deep reactive ion etched anti-reflection coatings for sub-millimeter silicon optics |
we present new abundances derived from cu i, cu ii, zn i, and zn ii lines in six warm (5766 ≤ {t}eff} ≤ 6427 k), metal-poor (-2.50 ≤ [fe/h] ≤ -0.95) dwarf and subgiant (3.64 ≤ log g ≤ 4.44) stars. these abundances are derived from archival high-resolution ultraviolet spectra from the space telescope imaging spectrograp... | a new test of copper and zinc abundances in late-type stars using ultraviolet cu ii and zn ii lines |
a multiwavelength temporal and spectral analysis of flares of 3c 279 during 2017 november-2018 july are presented in this work. three bright gamma-ray flares were observed simultaneously in x-ray and optical/uv along with a prolonged quiescent state. a "harder-when-brighter" trend is observed in both gamma-rays and x-r... | broadband variability and correlation study of 3c 279 during flares of 2017-2018 |
optical reflected light eclipse observations provide a direct probe of exoplanet scattering properties, such as from aerosols. we present here the photometric reflected light observations of wasp-43b using the hubble space telescope (hst) wfc3/uvis instrument with the f350lp filter (346-822 nm) encompassing the entire ... | the dark world: a tale of wasp-43b in reflected light with hst wfc3/uvis |
the gravitational field of a laser pulse of finite lifetime, is investigated in the framework of linearized gravity. although the effects are very small, they may be of fundamental physical interest. it is shown that the gravitational field of a linearly polarized light pulse is modulated as the norm of the correspondi... | gravitational properties of light—the gravitational field of a laser pulse |
type 2 active galactic nuclei (agns) show signatures of accretion onto a supermassive black hole through strong, high-ionization, narrow emission lines extended on scales of hundreds to thousands of parsecs, but they lack the broad emission lines from close in to the black hole that characterize type 1 agns. the lack o... | nustar observations of agns with low observed x-ray to [o iii] luminosity ratios: heavily obscured agns or turned-off agns? |
we present multiband hubble space telescope imaging that spans rest-frame near-ultraviolet through near-infrared wavelengths ( ${\lambda }_{\mathrm{rest}}=0.3$ -1.1 μm) for 12 compact starburst galaxies at z = 0.4-0.8. these massive galaxies ( ${{ \mathcal m }}_{* }\sim {10}^{11}\,{{ \mathcal m }}_{\odot }$ ) are drivi... | compact starburst galaxies with fast outflows: central escape velocities and stellar mass surface densities from multiband hubble space telescope imaging |
the durham adaptive optics simulation platform (dasp) is a monte-carlo modelling tool used for the simulation of astronomical and solar adaptive optics systems. in recent years, this tool has been used to predict the expected performance of the forthcoming extremely large telescope adaptive optics systems, and has seen... | the durham adaptive optics simulation platform (dasp): current status |
context. one of the most important aspects of modern astrophysics is related to our understanding of the origin of elements and chemical evolution in the large variety of astronomical sources. nuclear regions of galaxies undergo heavy processing of matter, and are therefore ideal targets to investigate matter cycles vi... | spatially resolved carbon and oxygen isotopic ratios in ngc 253 using optically thin tracers |
we report on a hubble space telescope detection of the nearby, old pulsar b0950+08 (d≃ 262 pc, spin-down age 17.5 myr) in two far-ultraviolet (fuv) bands. we measured the mean flux densities {\bar{f}}ν =109+/- 6 njy and 83 ± 14 njy in the f125lp and f140lp filters (pivot wavelengths 1438 and 1528 å). using the fuv data... | old but still warm: far-uv detection of psr b0950+08 |
in the last decade a number of rapidly evolving transients have been discovered that are not easily explained by traditional supernova models. we present optical and uv data on one such object, sn 2018gep, that displayed a fast rise with a mostly featureless blue continuum around peak, and evolved to develop broad feat... | the exotic type ic broad-lined supernova sn 2018gep: blurring the line between supernovae and fast optical transients |
thomas young's slit experiment lies at the heart of classical interference and quantum mechanics. over the last fifty years, it has been shown that particles (e.g. photons, electrons, large molecules), even individual particles, generate an interference pattern at a distant screen after passage through a double slit, t... | quantum memories and the double-slit experiment: implications for astronomical interferometry |
we present a sample of 24 local star-forming galaxies observed with broadband and narrowband photometry from the hubble space telescope (hst) that are part of the great observatories all-sky luminous infrared galaxies survey of local luminous and ultraluminous infrared galaxies. with narrowband filters around the emiss... | high-resolution hubble space telescope imaging survey of local star-forming galaxies. i. spatially resolved obscured star formation with hα and paschen-β recombination lines |
nearby m-dwarf systems currently offer the most favorable opportunities for spectroscopic investigations of terrestrial exoplanet atmospheres. the ltt 1445 system is a hierarchical triple of m dwarfs with two known planets orbiting the primary star, ltt 1445a. we observe four transits of the terrestrial world ltt 1445a... | ground-based optical transmission spectroscopy of the nearby terrestrial exoplanet ltt 1445ab |
dust-induced polarization in the interstellar medium (ism) is due to asymmetric grains aligned with an external reference direction, usually the magnetic field. for both the leading alignment theories, the alignment of the grain's angular momentum with one of its principal axes and the coupling with the magnetic field ... | grain alignment in the circumstellar shell of irc+10° 216 |
precise radial velocity (prv) surveys are important for the search for earth analogs around nearby bright stars, which induce a small stellar reflex motion with an rv amplitude of ~10 cm s-1. detecting such a small rv signal poses challenges to instrumentation, data analysis, and the precision of astrophysical models t... | characterizing and mitigating the impact of telluric absorption in precise radial velocities |
direct detection of gravitational waves (gws) on 17 august 2017, propagating from a binary neutron star merger, or a "kilonova", opened the era of multimessenger astronomy. the ejected material from neutron star mergers, or "kilonova", is a good candidate for optical and near infrared follow-up observations after the d... | relativistic atomic structure of au iv and the os isoelectronic sequence: opacity data for kilonova ejecta |
the article provides a review of the current state of affairs in the field of physics and technology of multilayer beryllium-containing mirrors intended for projection lithography and solar corona studies in the extreme ultraviolet (euv) region. the methods of synthesizing and studying beryllium-containing multilayer m... | beryllium-based multilayer x-ray optics |
the luminosities of type ia supernovae (sne), the thermonuclear explosions of white-dwarf stars, vary systematically with their intrinsic color and the rate at which they fade. from images taken with the galaxy evolution explorer (galex), we identified sne ia that erupted in environments that have high ultraviolet surf... | distances with <4% precision from type ia supernovae in young star-forming environments |
context. young stars interact with their accretion disk through their strong magnetosphere.aims: we aim to investigate the magnetospheric accretion/ejection process in the young stellar system doar 44 (v2062 oph).methods: we monitored the system over several rotational cycles, combining high-resolution spectropolarimet... | investigating the magnetospheric accretion process in the young pre-transitional disk system doar 44 (v2062 oph). a multiwavelength interferometric, spectropolarimetric, and photometric observing campaign |
we used high-resolution optical hubble space telescope/wfc3 and multiconjugate adaptive optics assisted gemini gems/gemini south adaptive optics imager observations in the near-infrared (nir) to investigate the physical properties of the globular cluster (gc) ngc 6569 in the galactic bulge. we have obtained the deepest... | a panchromatic view of the bulge globular cluster ngc 6569 |
we present the results from a search for the electromagnetic counterpart of the ligo/virgo event s190510g using the dark energy camera (decam). s190510g is a binary neutron star (bns) merger candidate of moderate significance detected at a distance of 227 ± 92 mpc and localized within an area of 31 (1166) square degree... | a desgw search for the electromagnetic counterpart to the ligo/virgo gravitational-wave binary neutron star merger candidate s190510g |
for natural guide star adaptive optics (ao) systems, pyramid wavefront sensors (pwfss) can provide a significant increase in sensitivity over the traditional shack-hartmann but at the cost of a reduced linear range. when using a linear reconstructor, nonlinearities result in wavefront estimation errors, which can have ... | mitigating the nonlinearities in a pyramid wavefront sensor |
we present the first analysis of jwst near-infrared spectroscopy of stellar flares from trappist-1 during transits of rocky exoplanets. four flares were observed from 0.6-2.8 μm with the near infrared imager and slitless spectrograph and 0.6-3.5 μm with the near infrared spectrograph during transits of trappist-1b, f, ... | characterizing the near-infrared spectra of flares from trappist-1 during jwst transit spectroscopy observations |
in the coming decade, up to 100 000 satellites in large constellations could be launched into low earth orbit. the satellites will introduce a variety of negative impacts on astronomy observatories and science, which vary from negligible to very disruptive depending on the type of instrument, the position of the scienc... | analysing the impact of satellite constellations and eso's role in supporting the astronomy community |
we introduce a novel machine-learning framework for estimating the bayesian posteriors of morphological parameters for arbitrarily large numbers of galaxies. the galaxy morphology posterior estimation network (gampen) estimates values and uncertainties for a galaxy's bulge-to-total-light ratio (lb /lt ), effective radi... | gampen: a machine-learning framework for estimating bayesian posteriors of galaxy morphological parameters |
we study the three-dimensional structure of the milky way using 65,981 mira variable stars discovered by the optical gravitational lensing experiment survey. the spatial distribution of the mira stars is analyzed with a model containing three barred components that include the x-shaped boxy component in the galactic ce... | a three-dimensional map of the milky way using 66,000 mira variable stars |
the spatial resolution of astronomical images is limited by atmospheric turbulence and diffraction in the telescope optics, resulting in blurred images. this makes it difficult to accurately measure the brightness of blended objects because the contributions from adjacent objects are mixed in a time-variable manner due... | starred: a two-channel deconvolution method with starlet regularization |
on 2019 august 14 at 21:10:39 utc, the ligo/virgo collaboration (lvc) detected a possible neutron star-black hole merger (nsbh), the first ever identified. an extensive search for an optical counterpart of this event, designated gw190814, was undertaken using the dark energy camera on the 4 m victor m. blanco telescope... | soar/goodman spectroscopic assessment of candidate counterparts of the ligo/virgo event gw190814 |
the effects of a quadratic gravity on astronomical observations and solar system experiments were recently considered in previous works. its deviation from einstein’s general relativity is characterized by a model parameter α and the cosmological constant λ whose constraints were respectively found as m2 and m-2 in the... | probing f(t) gravity with gravitational time advancement |
the next generation of extremely large telescopes (elt), with diameters up to 39 meters, is planned to begin operation in the next decade and promises new challenges in the development of instruments since the instrument size increases in proportion to the telescope diameter d, and the cost as d2 or faster. the growing... | spectrographs for astrophotonics |
the ability to control the propagation of light through scattering media is essential for atmospheric optics, astronomy, biomedical imaging, and remote sensing. the optimization of focusing light through a scattering medium is of particular interest for the case of highly scattering materials. optical wavefront beam-sh... | optimization of focusing through scattering media using the continuous sequential algorithm |
context. b[e] supergiants are evolved massive stars, enshrouded in a dense wind and surrounded by a molecular and dusty disk. the mechanisms that drive phases of enhanced mass loss and mass ejections, responsible for the shaping of the circumstellar material of these objects, are still unclear.aims: we aim to improve o... | inhomogeneous molecular ring around the b[e] supergiant lha 120-s 73 |
the detonation of a thin (≲0.03 m ⊙) helium shell (he-shell) atop a ~1 m ⊙ white dwarf (wd) is a promising mechanism to explain normal type ia supernovae (sne ia), while thicker he-shells and less massive wds may explain some recently observed peculiar sne ia. we present observations of sn 2020jgb, a peculiar sn ia dis... | sn 2020jgb: a peculiar type ia supernova triggered by a helium-shell detonation in a star-forming galaxy |
we present hubble space telescope wfc3/ir images of the cassiopeia a supernova remnant that survey its high-velocity, s-rich debris in the ne jet and sw counterjet regions through [s iii] λλ9069, 9531 and [s ii] λλ10,287-10,370 line emissions. we identify nearly 3400 sulfur emitting knots concentrated in ∼120° wide opp... | an hst survey of the highest-velocity ejecta in cassiopeia a |
increasingly powerful and multiplexed spectroscopic facilities promise detailed chemical abundance patterns for millions of resolved stars in galaxies beyond the milky way (mw). here, we employ the cramér-rao lower bound (crlb) to forecast the precision to which stellar abundances for metal-poor, low-mass stars outside... | forecasting chemical abundance precision for extragalactic stellar archaeology |
we present 81 near-infrared (nir) spectra of 30 type ii supernovae (sne ii) from the carnegie supernova project-ii (csp-ii), the largest such data set published to date. we identify a number of nir features and characterize their evolution over time. the nir spectroscopic properties of sne ii fall into two distinct gro... | carnegie supernova project-ii: near-infrared spectroscopic diversity of type ii supernovae |
the xmm-rm project was designed to provide x-ray coverage of the sloan digital sky survey reverberation mapping (sdss-rm) field. forty-one xmm-newton exposures, placed surrounding the chandra aegis field, were taken, covering an area of 6.13 deg2 and reaching a nominal exposure depth of ∼15 ks. we present an x-ray cata... | the sloan digital sky survey reverberation mapping project: the xmm-newton x-ray source catalog and multiband counterparts |
we present an improved proper-motion measurement of the central compact object rx j0822-4300, located in the supernova remnant puppis a. by employing a new data set taken in 2019 february by the high resolution camera on board the chandra x-ray observatory, we approximately double the available temporal baseline for ou... | the proper motion of the central compact object rx j0822-4300 in the supernova remnant puppis a, revisited |
vla 1623 west is an ambiguous source that has been described as a shocked cloudlet as well as a protostellar disk. we use deep alma 1.3 and 0.87 mm observations to constrain its shape and structure to determine its origins better. we use a series of geometric models to fit the uv visibilities at both wavelengths with g... | a millimeter-multiwavelength continuum study of vla 1623 west |
coronagraphs allow for faint off-axis exoplanets to be observed, but are limited to angular separations greater than a few beam widths. accessing closer-in separations would greatly increase the expected number of detectable planets, which scales inversely with the inner working angle. the vortex fiber nuller (vfn) is ... | efficient detection and characterization of exoplanets within the diffraction limit: nulling with a mode-selective photonic lantern |
current synoptic sky surveys monitor large areas of the sky to find variable and transient astronomical sources. as the number of detections per night at a single telescope easily exceeds several thousand, current detection pipelines make intensive use of machine learning algorithms to classify the detected objects and... | convolutional neural networks for transient candidate vetting in large-scale surveys |
free space optical links between the ground and space may be severely degraded by atmospheric turbulence. adaptive optics, a technique allowing partial correction of this degradation, is beginning to see use in the field with the potential to achieve more robust and higher bandwidth links. here we present a simulation ... | fast: fourier domain adaptive optics simulation tool for bidirectional ground-space optical links through atmospheric turbulence |
two exact lens equations have been recently shown to be equivalent to each other, being consistent with the gravitational deflection angle of light from a source to an observer, both of which can be within a finite distance from a lens object [phys. rev. d 102, 064060 (2020), 10.1103/physrevd.102.064060]. we examine me... | iterative solutions for the gravitational lens equation in the strong deflection limit |
we analyze the resolved stellar populations of the faint stellar system, crater, based on deep optical imaging taken with the advanced camera for surveys on the hubble space telescope. crater’s color-magnitude diagram (cmd) extends ∼4 mag below the oldest main-sequence (ms) turnoff. structurally, we find that crater ha... | a hubble space telescope study of the enigmatic milky way halo globular cluster crater* |
kiloparsec-scale dual active galactic nuclei (agns) are active supermassive black hole pairs co-rotating in galaxies with separations of less than a few kpc. expected to be a generic outcome of hierarchical galaxy formation, their frequency and demographics remain uncertain. we have carried out an imaging survey with t... | hubble space telescope wide field camera 3 identifies an rp= 1 kpc dual active galactic nucleus in the minor galaxy merger sdss j0924+0510 at z = 0.1495 |
we present an update on the 3.6-m aperture optical telescope, which has been installed at devasthal in the year 2016. in this paper, a brief overview of installation activities at site and first results are presented. the 3.6-m devasthal optical telescope project was initiated in 2007 by the aryabhatta research institu... | 3.6-m devasthal optical telescope project: completion and first results |
this short document is intended as a companion and introduction to the detailed science case (dsc) for the maunakea spectroscopic explorer. it provides a concise summary of the essential characteristics of mse from the perspective of the international astronomical community. mse is a wide field telescope (1.5 square de... | a concise overview of the maunakea spectroscopic explorer |
recently some pessimism has been expressed about our lack of progress in understanding quasars over more than fifty year since their discovery. it is worthwhile to look back at some of the progress that has been made - but still lies under the radar - perhaps because few people are working on optical/uv spectroscopy in... | quasars in the 4d eigenvector 1 context: a stroll down memory lane |
we present a new method to measure colors and magnitudes of the tip of the red giant branch (tgrb) in multiple bandpasses simultaneously by fitting an n-dimensional gaussian to photometry of candidate tip stars. we demonstrate that this method has several advantages over traditional edge detection, particularly in regi... | mcr-trgb: a multiwavelength-covariant, robust tip of the red giant branch measurement method |
we present reverberation mapping measurements for the prominent ultraviolet broad emission lines of the active galactic nucleus mrk 817 using 165 spectra obtained with the cosmic origins spectrograph on the hubble space telescope. our ultraviolet observations are accompanied by x-ray, optical, and near-infrared observa... | agn storm 2. ii. ultraviolet observations of mrk 817 with the cosmic origins spectrograph on the hubble space telescope |
the model of atmosphere optical turbulence is important in the research field of laser atmospheric transmission, and plays a key role in astronomical site selection. in this paper, the single and overall statistical analysis between different outer scale models (hmnsp99 and the dewan model) were conducted and the resul... | analysis of the optical turbulence model using meteorological data |
the laser interferometer space antenna (lisa) will enable galactic gravitational wave (gw) astronomy by individually resolving >104 signals from double white dwarf (dwd) binaries throughout the milky way. since gws are unaffected by stellar crowding and dust extinction unlike optical observations of the galactic pla... | the milky way's bar structural properties from gravitational waves |
context. the evolution and structure of the magellanic clouds is currently under debate. the classical scenario in which both the large and small magellanic clouds (lmc, smc) are orbiting the milky way has been challenged by an alternative in which the lmc and smc are in their first close passage to our galaxy. the clo... | smc west halo: a slice of the galaxy that is being tidally stripped?. star clusters trace age and metallicity gradients |
most star clusters at an intermediate age (1-2 gyr) in the large and small magellanic clouds show a puzzling feature in their color-magnitude diagrams (cmd) that is not in agreement with a simple stellar population. the main sequence turn-off of these clusters is much broader than expected from photometric uncertaintie... | controversial age spreads from the main sequence turn-off and red clump in intermediate-age clusters in the lmc |
we present a high-resolution (r ∼ 35,000), high signal-to-noise ratio (s/n > 200) magellan/mike spectrum of the star rave j094921.8-161722, a bright (v = 11.3) metal-poor red giant star with [fe/h] = -2.2, identified as a carbon-enhanced metal-poor (cemp) star from the rave survey. we report its detailed chemical ab... | the r-process alliance: discovery of the first metal-poor star with a combined r- and s-process element signature |
using molecular line data from the millimetre astronomy legacy team 90 ghz survey, we have searched the optically thick hco+ (1-0) line for the “blue asymmetry” spectroscopic signature of infall motion in a large sample of high-mass, dense molecular clumps observed to be at different evolutionary stages of star cluster... | asymmetric line profiles in dense molecular clumps observed in malt90: evidence for global collapse |
we investigate the eddington ratio distribution of x-ray-selected broad-line active galactic nuclei (agns) in the redshift range 1.0 < z < 2.2, where the number density of agns peaks. combining the optical and subaru/fiber multi object spectrograph near-infrared spectroscopy, we estimate black hole masses for bro... | eddington ratio distribution of x-ray-selected broad-line agns at 1.0 < z < 2.2 |
context. fu orionis is the archetypal fuor star, a subclass of young stellar objects (ysos) that undergo rapid brightening events, often gaining between four and six magnitudes on timescales of days. this brightening is often associated with a massive increase in accretion, which is one of the most ubiquitous processes... | viscous heating in the disk of the outbursting star fu orionis |
predictive wavefront control is an important and rapidly developing field of adaptive optics (ao). through the prediction of future wavefront effects, the inherent ao system servo-lag caused by the measurement, computation, and application of the wavefront correction can be significantly mitigated. this lag can impact ... | closed loop predictive control of adaptive optics systems with convolutional neural networks |
the ultraviolet (uv) emission from the most numerous stars in the universe, m dwarfs, impacts the formation, chemistry, atmospheric stability, and surface habitability of their planets. we have analyzed the spectral evolution of uv emission from m0-m2.5 (0.3-0.6 m⊙) stars as a function of age, rotation, and rossby numb... | hazmat. vii. the evolution of ultraviolet emission with age and rotation for early m dwarf stars |
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