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the analysis of phenyl isocyanide (c6h5nc, μa = 4.0 d) in its ground vibrational state and two lowest-energy excited vibrational states, ν22 (141 cm-1) and ν33 (155 cm-1), in the 130-370 ghz frequency region has been completed. over 4500 new rotational transitions have been measured in the ground vibrational state for ... | the 130-370 ghz rotational spectrum of phenyl isocyanide (c6h5nc) |
the edges high-band experiment aims to detect the sky-average brightness temperature of the 21 cm signal from the epoch of reionization in the redshift range 14.8≳ z≳ 6.5. to probe this redshifted signal, edges high-band conducts single-antenna measurements in the frequency range 90-190 mhz from the murchison radio-ast... | calibration of the edges high-band receiver to observe the global 21 cm signature from the epoch of reionization |
fast radio bursts (frbs) are mysterious extragalactic radio signals. revealing their origin is one of the central foci in modern astronomy. previous studies suggest that occurrence rates of non-repeating and repeating frbs could be controlled by the cosmic stellar-mass density (csmd) and cosmic star formation-rate dens... | fast radio bursts to be detected with the square kilometre array |
in recent years, dramatic outbursts have been identified toward massive protostars via infrared and millimeter dust continuum and molecular maser emission. the longest lived outburst (>6 yr) persists in ngc 6334 i-mm1, a deeply embedded object with no near-ir counterpart. using forcast and hawc+ on sofia, we have ob... | the extraordinary outburst in the massive protostellar system ngc 6334 i-mm1: strong increase in mid-infrared continuum emission |
the chinese spectral radioheliograph (csrh) covering 400 mhz-15 ghz frequency range was constructed during 2009-2016 in mingantu observing station, national astronomical observatories, chinese academy of sciences at zhengxiangbaiqi, inner mongolia of china. csrh is renamed as {\it m}ingant{\it u} {\it s}p{\it e}ctral {... | mingantu spectral radioheliograph for solar and space weather studies |
the tianlai cylinder pathfinder is a radio interferometer array designed to test techniques for 21 cm intensity mapping in the post-reionization universe, with the ultimate aim of mapping the large scale structure and measuring cosmological parameters such as the dark energy equation of state. each of its three paralle... | the tianlai cylinder pathfinder array: system functions and basic performance analysis |
technosignatures refer to observational manifestations of technology that could be detected through astronomical means. most previous searches for technosignatures have focused on searches for radio signals, but many current and future observing facilities could also constrain the prevalence of some non-radio technosig... | searching for technosignatures in exoplanetary systems with current and future missions |
the growth of galaxies in the early universe is driven by accretion of circum- and intergalactic gas. simulations have predicted that steady streams of cold gas penetrate the dark matter halos of galaxies and provide the raw material necessary to sustain star formation. we report a filamentary stream of gas that extend... | a cosmic stream of atomic carbon gas connected to a massive radio galaxy at redshift 3.8 |
aims: observations of free-free continuum radio emission of four young main-sequence solar-type stars (ek dra, π1 uma, χ1 ori, and κ1 cet) are studied to detect stellar winds or at least to place upper limits on their thermal radio emission, which is dominated by the ionized wind. the stars in our sample are members of... | radio emission and mass loss rate limits of four young solar-type stars |
a variety of large-scale diffuse radio structures have been identified in many clusters with the advent of new state-of-the-art facilities in radio astronomy. among these diffuse radio structures, radio mini-halos are found in the central regions of cool core clusters. their origin is still unknown and they are challen... | on the relation between mini-halos and agn feedback in clusters of galaxies |
polarimetric observations of fast radio bursts (frbs) are a powerful resource for better understanding these mysterious sources by directly probing the emission mechanism of the source and the magneto-ionic properties of its environment. we present a pipeline for analyzing the polarized signal of frbs captured by the t... | polarization pipeline for fast radio bursts detected by chime/frb |
we present the detection of the kinetic sunyaev-zel'dovich effect (ksze) signals from groups of galaxies as a function of halo mass down to $\mathrm{log}({m}_{500}/{m}_{\odot })\sim 12.3$ using the planck cosmic microwave background maps and stacking about 40,000 galaxy systems with known positions, halo masses, and pe... | detection of missing baryons in galaxy groups with kinetic sunyaev-zel'dovich effect |
the presence of a large-scale surface magnetic field in early-type stars leads to several unique electromagnetic phenomena producing radiation over x-ray to radio bands. among them, the rarest type of emission is electron cyclotron maser emission (ecme) observed as periodic, circularly polarized radio pulses. the pheno... | ultra-wideband, multiepoch radio study of the first discovered "main-sequence radio pulse emitter" cu vir |
precise detection and monitoring of the frequency spectrum of microwave signals are essential to myriad scientific and technological disciplines, including both civil and defense areas, such as telecommunications, radar, biomedical instrumentation, radio astronomy, etc. historically, microwave engineering has provided ... | towards on-chip photonic-assisted radio-frequency spectral measurement and monitoring |
statcont is a python-based tool designed to determine the continuum emission level in spectral data, in particular for sources with a line-rich spectrum. the tool inspects the intensity distribution of a given spectrum and automatically determines the continuum level by using different statistical approaches. the diffe... | statcont: a statistical continuum level determination method for line-rich sources |
a novel concept for chinese chang'e-4 lunar exploration mission is presented in this paper at first. after the success of chang'e-3, its backup probe, chang'e-4 lander/rover combination, would be upgraded and land on the unexplored lunar farside by the aid of a relay satellite near the second earth-moon lagrange point.... | a chang'e-4 mission concept and vision of future chinese lunar exploration activities |
the current status of the large decameter radio telescope utr-2 (ukrainian t-shaped radio telescope) together with its vlbi system called uran is described in detail. by modernization of these instruments through implementation of novel versatile analog and digital devices as well as new observation techniques, the obs... | the modern radio astronomy network in ukraine: utr-2, uran and gurt |
new functionality to process very long baseline interferometry (vlbi) data has been implemented in the casa package. this includes two new tasks to handle fringe fitting and vlbi-specific amplitude calibration steps. existing tasks have been adjusted to handle vlbi visibility data and calibration meta-data properly. wi... | casa on the fringe-development of vlbi processing capabilities for casa |
this paper demonstrates a novel and efficient unsupervised clustering method with the combination of a self-organizing map (som) and a convolutional autoencoder. the rapidly increasing volume of radio-astronomical data has increased demand for machine-learning methods as solutions to classification and outlier detectio... | radio galaxy zoo: unsupervised clustering of convolutionally auto-encoded radio-astronomical images |
the comparison of distant atomic clocks is foundational to international timekeeping, global positioning and tests of fundamental physics. optical-fibre links allow the most precise optical clocks to be compared, without degradation, over intracontinental distances up to thousands of kilometres, but intercontinental co... | intercontinental comparison of optical atomic clocks through very long baseline interferometry |
the multimessenger data of neutron star merger events are promising for constraining the hubble constant. so far, gw170817 is still the unique gravitational wave event with multiwavelength electromagnetic counterparts. in particular, its radio and x-ray emission have been measured in the past ~3-5 yr. in this work, we ... | the late afterglow of gw170817/grb 170817a: a large viewing angle and the shift of the hubble constant to a value more consistent with the local measurements |
saras is an ongoing experiment aiming to detect the redshifted global 21-cm signal expected from cosmic dawn (cd) and the epoch of reionization (eor). standard cosmological models predict the signal to be present in the redshift range z ∼6-35, corresponding to a frequency range 40-200 mhz, as a spectral distortion of a... | saras 3 cd/eor radiometer: design and performance of the receiver |
outbursts from active galactic nuclei (agn) can inflate cavities in the intracluster medium (icm) of galaxy clusters and are believed to play the primary role in offsetting radiative cooling in the icm. however, the details of how the energy from agn feedback thermalizes to heat the icm is not well understood, partly d... | constraints on the thermal contents of the x-ray cavities of cluster ms 0735.6+7421 with sunyaev-zel’dovich effect observations |
the event horizon telescope consortium is on the verge to provide the first telescopic image of massive black holes sgra* and m87* surrounded by accretion disks, at a resolution scale comparable to the size of their event horizons. well before this remarkable achievement made possible by vlbi radio astronomy, many rese... | an illustrated history of black hole imaging : personal recollections (1972-2002) |
we report on the galaxy macsj0032-arc at zco = 3.6314 discovered during the herschel lensing snapshot survey of massive galaxy clusters, and strongly lensed by the cluster macs j0032.1+1808. the successful detections of its rest-frame ultraviolet (uv), optical, far-infrared (fir), millimeter, and radio continua, and of... | molecular gas properties of a lensed star-forming galaxy at z 3.6: a case study |
regardless of whether or not all fast radio bursts (frbs) repeat, those that do form a population with a distribution of rates. this work considers a power-law model of this population, with rate distribution $φ_r ∼ r^{{γ_r}}$ between ${r_min}$ and ${r_max}$ . the zdm code is used to model the probability of detecting ... | modelling repetition in zdm: a single population of repeating fast radio bursts can explain chime data |
in radio astronomy obtaining a high dynamic range in synthesis imaging of wide fields requires a correction for time and direction-dependent effects. applying direction-dependent correction can be done by either partitioning the image in facets and applying a direction-independent correction per facet, or by including ... | image domain gridding: a fast method for convolutional resampling of visibilities |
direct measurements of distances to astronomical sources rely on parallax, which can usually only be measured for relatively nearby objects. the far side of the milky way has been impossible to measure accurately, because the parallax is very small and interstellar dust blocks optical light from those regions. sanna et... | mapping spiral structure on the far side of the milky way |
finding the electromagnetic (em) counterpart of binary compact star merger, especially the binary neutron star (bns) merger, is critically important for gravitational wave (gw) astronomy, cosmology and fundamental physics. on aug. 17, 2017, advanced ligo and fermi/gbm independently triggered the first bns merger, gw170... | insight-hxmt observations of the first binary neutron star merger gw170817 |
increasing data volumes delivered by a new generation of radio interferometers require computationally efficient and robust calibration algorithms. in this paper, we propose distributed calibration as a way of improving both computational cost as well as robustness in calibration. we exploit the data parallelism across... | distributed radio interferometric calibration |
fast radio bursts (frbs) are being detected with increasing regularity. however, their spontaneous and often once-off nature makes high-precision burst position and frequency-time structure measurements difficult without specialised real-time detection techniques and instrumentation. the australian square kilometre arr... | celebi: the craft effortless localisation and enhanced burst inspection pipeline |
radio emission from tidal disruption events (tdes) originates from an interaction of an outflow with the super-massive black hole (smbh) circumnuclear material (cnm). in turn, this radio emission can be used to probe properties of both the outflow launched at the event and the cnm. until recently, radio emission was de... | are delayed radio flares common in tidal disruption events? the case of the tde iptf 16fnl |
recent observations have shown that repeating fast radio bursts (frbs) exhibit band-limited emission, whose frequency-dependent amplitude can be modeled using a gaussian function. in this analysis, we show that banded emission of frbs can lead to incompleteness across the observing band. this biases the detected sample... | observational effects of banded repeating frbs |
we report on a ~5σ detection of polarized 3-6 kev x-ray emission from the supernova remnant cassiopeia a (cas a) with the imaging x-ray polarimetry explorer (ixpe). the overall polarization degree of 1.8% ± 0.3% is detected by summing over a large region, assuming circular symmetry for the polarization vectors. the mea... | x-ray polarization detection of cassiopeia a with ixpe |
context. the low frequency array (lofar) two-metre sky survey (lotss) is a low-frequency radio continuum survey of the northern sky at an unparalleled resolution and sensitivity.aims: in order to fully exploit this huge dataset and those produced by the square kilometre array in the next decade, automated methods in ma... | unveiling the rarest morphologies of the lofar two-metre sky survey radio source population with self-organised maps |
in plasmas with a large ratio of plasma frequency to gyrofrequency (ωpe/ωce), energetic electrons characterized by \partial f/\partial {v}_{\perp }> 0 can excite electron cyclotron maser instability (ecmi), generating waves of upper hybrid (uh), z, and w modes. it has been presumed that these ecmi waves can somehow ... | plasma emission induced by electron cyclotron maser instability in solar plasmas with a large ratio of plasma frequency to gyrofrequency |
we present time series analyses of three-decade long radio observations of the bl lacertae object ao 0235+164 made at the university of michigan radio astronomical observatory operating at three central frequencies of 4.8, 8.0, and 14.5 ghz. we detected a quasi-periodic oscillation of ~965 d in all three frequency band... | quasi-periodic oscillations in the long-term radio light curves of the blazar ao 0235+164 |
the common phenomenon of lightning still harbors many secrets and only recently a new propagation mode was observed for negative leaders. while propagating in this "intensely radiating negative leader" (irnl) mode a negative leader emits 100 times more very-high frequency (vhf) and broadband radiation than a more norma... | interferometric imaging of intensely radiating negative leaders |
in this chapter we provide an overview of the science enabled by radio continuum surveys in the ska era, focusing on galaxy/galaxy cluster physics and evolution studies, and other relevant continuum science in the >2020 scientific framework. we outline a number of 'reference' radio-continuum surveys for ska1 that ca... | revealing the physics and evolution of galaxies and galaxy clusters with ska continuum surveys |
the euclid space telescope will provide deep imaging at optical and near-infrared wavelengths, along with slitless near-infrared spectroscopy, across ~15 000deg2 of the sky. euclid is expected to detect ~12 billion astronomical sources, facilitating new insights into cosmology, galaxy evolution, and various other topic... | euclid preparation. xxii. selection of quiescent galaxies from mock photometry using machine learning |
in radio astronomy, signals from radio telescopes are transformed into images of observed celestial objects, or sources. however, these images, called dirty images, contain real sources as well as artifacts due to signal sparsity and other factors. therefore, radio interferometric image reconstruction is performed on d... | a conditional denoising diffusion probabilistic model for radio interferometric image reconstruction |
extreme scattering events (eses) are distinctive fluctuations in the brightness of astronomical radio sources caused by occulting plasma lenses in the interstellar medium. the inferred plasma pressures of the lenses are ~103 times the ambient pressure, challenging our understanding of gas conditions in the milky way. u... | real-time detection of an extreme scattering event: constraints on galactic plasma lenses |
rotational and rovibrational spectra of methyl cyanide were recorded to analyze interactions in low-lying vibrational states and to construct line lists for radio astronomical observations as well as for infrared spectroscopic investigations of planetary atmospheres. the rotational spectra cover large portions of the 3... | rotational spectroscopy as a tool to investigate interactions between vibrational polyads in symmetric top molecules: low-lying states v8 ⩽ 2 of methyl cyanide, ch3cn |
we present co(1-0) observations of objects within the shocked poststarburst galaxy survey taken with the institut de radioastronomie millimétrique 30 m single dish and the combined array for research for millimeter astronomy interferometer. shocked poststarburst galaxies (spogs) represent a transitioning population of ... | shocked poststarburst galaxy survey. ii. the molecular gas content and properties of a subset of spogs |
we present a catalog of 510 radio-loud active galactic nuclei (agns, primarily blazars) and 287 dusty star-forming galaxies (dsfgs) detected by the atacama cosmology telescope at $\gt 5\sigma $ significance in frequency bands centered on 148 ghz (2 mm), 218 ghz (1.4 mm), and 277 ghz (1.1 mm), from a 480 deg2 strip cent... | atacama cosmology telescope: dusty star-forming galaxies and active galactic nuclei in the equatorial survey |
point source detection at low signal-to-noise ratio (snr) is challenging for astronomical surveys, particularly in radio interferometry images where the noise is correlated. machine learning is a promising solution, allowing the development of algorithms tailored to specific telescope arrays and science cases. we prese... | deepsource: point source detection using deep learning |
we present the first fully automated pipeline for making images from the interferometric data obtained from the upgraded giant metrewave radio telescope (ugmrt) called casa pipeline-cum-toolkit for upgraded giant metrewave radio telescope data reduction - capture. it is a python program that uses tasks from the nrao co... | capture: a continuum imaging pipeline for the ugmrt |
ultracool dwarfs (ucds) are a category of astronomical objects that includes brown dwarfs and very-low-mass stars. radio observations of ucds have measured their brightness as a function of time (light curves) and spectral energy distributions, providing insight into their magnetic fields. we present spatially resolved... | evidence for a radiation belt around a brown dwarf |
more than 130 pure rotational transitions of 46tio, 47tio, 48tio, 49tio, 50tio, and 48ti18o are recorded using a high-resolution mm-wave supersonic jet spectrometer in combination with a laser ablation source. for the first time a mass-independent dunham-like analysis is performed encompassing rare titanium monoxide is... | mass-independent analysis of the stable isotopologues of gas-phase titanium monoxide - tio |
weight sharing in convolutional neural networks (cnns) ensures that their feature maps will be translation-equivariant. however, although conventional convolutions are equivariant to translation, they are not equivariant to other isometries of the input image data, such as rotation and reflection. for the classificatio... | fanaroff-riley classification of radio galaxies using group-equivariant convolutional neural networks |
covering both astronomical and geophysical perspectives, this book describes changes in the earth's orientation, specifically precession and nutation, and how they are observed and computed in terms of tidal forcing and models of the earth's interior. following an introduction to key concepts and elementary geodetic th... | precession, nutation and wobble of the earth |
we report on two millimeter flares detected by the atacama large millimeter/submillimeter array at 220 ghz from au mic, a nearby m dwarf. the larger flare had a duration of only ∼35 s, with peak lr = 2 × 1015 erg s-1 hz-1, and lower limit on linear polarization of | q/i| > 0.12 ± 0.04. we examine the characteristics... | properties of m dwarf flares at millimeter wavelengths |
axions are increasingly favoured as a candidate particle for the dark matter in galaxies, since they satisfy the observational requirements for cold dark matter and are theoretically well motivated. fluctuations in the axion field give rise to stable localized overdensities known as axion stars, which, for the most mas... | neutron star-axion star collisions in the light of multimessenger astronomy |
we present the first measurements of h i galaxy scaling relations from a blind survey at z > 0.15. we perform spectral stacking of 9023 spectra of star-forming galaxies undetected in h i at 0.23 < z < 0.49, extracted from mightee-h i early science data cubes, acquired with the meerkat radio telescope. we stack... | mightee-hi: evolution of hi scaling relations of star-forming galaxies at z < 0.5 |
the phenomenon of faraday rotation of linearly polarized synchrotron emission in a magneto-ionized medium has been understood and studied for decades. but since the sense of the rotation itself is irrelevant in most contexts, some uncertainty and inconsistencies have arisen in the literature about this detail. here, we... | the correct sense of faraday rotation |
we report the first detection on titan of the small cyclic molecule cyclopropenylidene (c-c3h2) from high-sensitivity spectroscopic observations made with the atacama large millimeter/submillimeter array. multiple lines of cyclopropenylidene were detected in two separate data sets: ∼251 ghz in 2016 (band 6) and ∼352 gh... | detection of cyclopropenylidene on titan with alma |
frb 180916 is a most intriguing source capable of producing repeating fast radio bursts with a periodic 16.3 day temporal pattern. the source is well positioned in a star-forming region in the outskirts of a nearby galaxy at 150 mpc distance. in this letter we report on the x-ray and γ-ray observations of frb 180916 ob... | gamma-ray and x-ray observations of the periodic-repeater frb 180916 during active phases |
due to the growing capacity of gravitational-wave astronomy and black-hole imaging, we will soon be able to emphatically decide if astrophysical dark objects lurking in galactic centers are black holes. sgr a*, one of the most prolific astronomical radio sources in our galaxy, is the focal point for tests of general re... | geodesics and gravitational waves in chaotic extreme-mass-ratio inspirals: the curious case of zipoy-voorhees black-hole mimickers |
the coherent low-frequency radio emission detected by lofar from gliese 1151, a quiescent m4.5 dwarf star, has radio emission properties consistent with theoretical expectations of star-planet interactions for an earth-sized planet on a 1- to 5-day orbit. new near-infrared radial velocities from the habitable-zone plan... | the habitable-zone planet finder detects a terrestrial-mass planet candidate closely orbiting gliese 1151: the likely source of coherent low-frequency radio emission from an inactive star |
we report the detection of magnesium dicarbide, mgc2, in the laboratory at centimeter wavelengths and assign 24mgc2, 25mgc2, and 26mgc2 to 14 unidentified lines in the radio spectrum of the circumstellar envelope of the evolved carbon star irc+10216. the structure of mgc2 is found to be t-shaped with a highly ionic bon... | laboratory and astronomical discovery of magnesium dicarbide, mgc2 |
sn 2018ivc is an unusual type ii supernova (sn ii). it is a variant of sne iil, which might represent a transitional case between sne iip with a massive h-rich envelope and sne iib with only a small amount of the h-rich envelope. however, sn 2018ivc shows an optical light-curve evolution more complicated than that of c... | a multiwavelength view of the rapidly evolving sn 2018ivc: an analog of sn iib 1993j but powered primarily by circumstellar interaction |
we identify 45 protostellar outflows in co maps of the orion a giant molecular cloud from the combined array for research in millimeter-wave astronomy-nobeyama radio observatory orion survey. our sample includes 11 newly detected outflows. we measure the mass and energetics of the outflows, including material at low ve... | the carma-nro orion survey: protostellar outflows, energetics, and filamentary alignment |
h i intensity mapping is a new observational technique to map fluctuations in the large-scale structure of matter using the 21 cm emission line of atomic hydrogen (h i). sensitive h i intensity mapping experiments have the potential to detect baryon acoustic oscillations at low redshifts (z ≲ 1) in order to constrain t... | extracting h i cosmological signal with generalized needlet internal linear combination |
we present recent very long baseline array (vlba) 5 ghz radio observations of the nearby, luminous seyfert 2 galaxy ngc 1068 for comparison to similar vlba observations made on 1997 april 26. by cross-correlating the positions of emitting regions across both epochs, we find that spatially resolved extranuclear radio kn... | no small-scale radio jets here: multiepoch observations of radio continuum structures in ngc 1068 with the vlba |
resolving the phase structure of neutral hydrogen (h i) is crucial for understanding the life cycle of the interstellar medium (ism). however, accurate measurements of h i temperature and density are limited by the availability of background continuum sources for measuring h i absorption. here we test the use of deep l... | extracting the cold neutral medium from h i emission with deep learning: implications for galactic foregrounds at high latitude |
in radio astronomy, radio frequency interference (rfi) becomes more and more serious for radio observational facilities. the rfi always influences the search and study of the interesting astronomical objects. mitigating the rfi becomes an essential procedure in any survey data processing. the five-hundred-meter apertur... | radio frequency interference mitigation and statistics in the spectral observations of fast |
we present the first detailed computations of wave optics effects in the gravitational lensing of binary systems. the field is conceptually rich, combining the caustic singularities produced in classical gravitational lensing with quantum (wave) interference effects. new techniques have enabled us to overcome previous ... | gravitational lensing of binary systems in wave optics |
we search for host galaxy candidates of nearby fast radio bursts (frbs), frb 180729.j1316+55, frb 171020, frb 171213, frb 180810.j1159+83, and frb 180814.j0422+73 (the second repeating frb). we compare the absolute magnitudes and the expected host dispersion measure dmhost of these candidates with that of the first rep... | the frb 121102 host is atypical among nearby fast radio bursts |
we conducted a search for technosignatures in 2018 and 2019 april with the l-band receiver (1.15-1.73 ghz) of the 100 m diameter green bank telescope. these observations focused on regions surrounding 31 sun-like stars near the plane of the galaxy. we present the results of our search for narrowband signals in this dat... | a search for technosignatures around 31 sun-like stars with the green bank telescope at 1.15-1.73 ghz |
the askap-emu survey is a deep wide-field radio continuum survey designed to cover the entire southern sky and a significant fraction of the northern sky up to +30°. here, we report a discovery of a radio relic in the merging cluster spt-cl j2023-5535 at z = 0.23 from the askap-emu pilot 300 square degree survey (800-1... | discovery of a radio relic in the massive merging cluster spt-cl j2023-5535 from the askap-emu pilot survey |
optical frequency combs have become indispensable in astronomical measurements, biological fingerprinting, optical metrology, and radio frequency photonic signal generation. recently demonstrated microring resonator-based kerr frequency combs point the way towards chip scale optical frequency comb generator retaining m... | on frequency combs in monolithic resonators |
current constraints on einstein's weak equivalence principle (wep) utilize the observed time delay between correlated particles of astronomical sources. however, the intrinsic time delay due to particle emission time and the time delays caused by potential lorentz-invariance violation and non-zero rest mass of photons ... | testing weak equivalence principle with strongly lensed cosmic transients |
this white paper describes the science case for very long baseline interferometry (vlbi) and provides suggestions towards upgrade paths for the european vlbi network (evn). the evn is a distributed long-baseline radio interferometric array, that operates at the very forefront of astronomical research. recent results, t... | vlbi20-30: a scientific roadmap for the next decade -- the future of the european vlbi network |
large deployable antennas are required for the advancement of space communications, earth observation, radio astronomy and deep space exploration. most contemporary space antennas have exceeded the size of launching vehicles, leading to the necessity of stowed concepts to overcome the limitation. many structural models... | optimal design and robust analysis of a net of active devices for micro-vibration control of an on-orbit large space antenna |
we present a case for significantly enhancing the utility and efficiency of the ngeht by incorporating an additional 86 ghz observing band. in contrast to 230 or 345 ghz, weather conditions at the ngeht sites are reliably good enough for 86 ghz to enable year-round observations. multi-frequency imaging that incorporate... | enabling transformational ngeht science via the inclusion of 86 ghz capabilities |
the origin of astrophysical high-energy neutrinos detected by the icecube neutrino observatory remains a mystery to be solved. in this paper we search for neutrino source candidates within the 90% containment area of 70 track-type neutrino events recorded by the icecube neutrino observatory. by employing the fermi-lat ... | multiwavelength search for the origin of icecube's neutrinos |
we report the detection of the propargyl radical (ch2cch) in the cold dark cloud tmc-1 in the λ 3 mm wavelength band. we recently discovered this species in space toward the same source at a wavelength of λ 8 mm. in those observations, various hyperfine components of the 20,2-10,1 rotational transition, at 37.5 ghz, we... | detection of the propargyl radical at λ 3 mm |
radio halos are diffuse synchrotron sources observed in dynamically unrelaxed galaxy clusters. current observations and models suggest that halos trace turbulent regions in the intracluster medium where mildly relativistic particles are reaccelerated during cluster mergers. due to the higher luminosities and detection ... | discovery of a radio halo (and relic) in a m500<2×1014 m⊙ cluster |
we present 3, 15, and 33 ghz imaging toward galaxy nuclei and extranuclear star-forming regions using the karl g. jansky very large array as part of the star formation in radio survey. with 3-33 ghz radio spectra, we measured the spectral indices and corresponding thermal (free-free) emission fractions for a sample of ... | the star formation in radio survey: 3-33 ghz imaging of nearby galaxy nuclei and extranuclear star-forming regions |
compact, continuously launched jets in black hole x-ray binaries (bhxbs) produce radio to optical/ir synchrotron emission. in most bhxbs, an ir excess (above the disk component) is observed when the jet is present in the hard spectral state. we investigate why some bhxbs have prominent ir excesses and some do not, quan... | lorentz factors of compact jets in black hole x-ray binaries |
gas has been detected in a number of debris disks. it is likely secondary, i.e., produced by colliding solids. here, we report alma band 8 observations of neutral carbon in the co-rich debris disk around the 15-30 myr old a-type star hd 32297. we find that c0 is located in a ring at ∼110 au with an fwhm of ∼80 au and h... | the surprisingly low carbon mass in the debris disk around hd 32297 |
models of the origin of astrophysical neutrinos with energies from tevs to pevs are strongly constrained by multimessenger observations and population studies. recent results point to statistically significant associations between these neutrinos and active galactic nuclei (agn) selected by their radio flux observed wi... | neutrino production in blazar radio cores |
the rapid development of new generation radio interferometers such as the square kilometer array (ska) has opened up unprecedented opportunities for astronomical research. however, anthropogenic radio frequency interference (rfi) from communication technologies and other human activities severely affects the fidelity o... | a robust rfi identification for radio interferometry based on a convolutional neural network |
the magnetic field is ubiquitous in the universe. though it plays an essential role in various astrophysical phenomena, its real origin and evolution are poorly known. this article reviews the understanding of the latest research concerning magnetic fields in the interstellar medium, the milky way galaxy, external gala... | cosmic magnetism in centimeter- and meter-wavelength radio astronomy |
we investigate the prospects for joint low-latency gravitational wave (gw) detection and prompt electromagnetic (em) follow-up observations of coalescing binary neutron stars (bnss). for bns mergers associated with short duration gamma-ray bursts (sgrbs), we for the first time evaluate the feasibility of rapid em follo... | capturing the electromagnetic counterparts of binary neutron star mergers through low-latency gravitational wave triggers |
next-generation radio surveys are about to transform radio astronomy by discovering and studying tens of millions of previously unknown radio sources. these surveys will provide fresh insights for understanding the evolution of galaxies, measuring the evolution of the cosmic star-formation rate, and rivalling tradition... | extragalactic radio continuum surveys and the transformation of radio astronomy |
in the period 2012 june-2013 october, the sardinia radio telescope (srt) went through the technical commissioning phase. the characterization involved three first-light receivers, ranging in frequency between 300mhz and 26ghz, connected to a total power back-end. it also tested and employed the telescope active surface... | sardinia radio telescope |
large polycyclic aromatic hydrocarbons (pahs) are the most abundant complex molecules in the interstellar medium; however, their possible formation pathways from small molecular species are still elusive. in the present work, we follow and characterize the formation of pahs in an electrical discharge, specifically the ... | polycyclic aromatic hydrocarbon formation chemistry in a plasma jet revealed by ir-uv action spectroscopy |
we examine a sample of 21 gamma-ray burst (grb) afterglow light curves at radio frequencies and compare them to the x-ray and/or optical properties of the afterglows and to the predictions of the standard jet/fireball model. our sample includes every swift grb with an x-ray light curve indicating a jet break and with a... | the late-time radio behavior of gamma-ray burst afterglows: testing the standard model |
the past two decades have witnessed a renewed interest in low frequency radio astronomy, with a particular focus on frequencies above 30 mhz e.g., lofar (low frequency array) in the netherlands and its european extension ilt, the international lofar telescope. however, at frequencies below 30 mhz, earth-based observati... | a roadmap towards a space-based radio telescope for ultra-low frequency radio astronomy |
radio relics are elongated sources related to shocks driven by galaxy cluster merger events. although these objects are highly polarized at ghz frequencies (≳20%), high-resolution studies of their polarization properties are still lacking. we present the first high-resolution and high-sensitivity polarimetry study of t... | downstream depolarization in the sausage relic: a 1-4 ghz very large array study |
we report the first detection in space of the cumulene carbon chain l-h2c5. a total of eleven rotational transitions, with jup = 7−10 and ka = 0 and 1, were detected in tmc-1 in the 31.0-50.4 ghz range using the yebes 40 m radio telescope. we derived a column density of (1.8 ± 0.5)×1010 cm−2. in addition, we report obs... | cumulene carbenes in tmc-1: astronomical discovery of l-h2c5 |
recent advances in imaging from celestial objects in astronomy visualized via optical and radio telescopes to atoms and molecules resolved via electron and probe microscopes are generating immense volumes of imaging data, containing information about the structure of the universe from atomic to astronomic levels. the c... | robust feature disentanglement in imaging data via joint invariant variational autoencoders: from cards to atoms |
we report the first identification in space of h2nc, a high-energy isomer of h2cn that has been largely ignored in chemical and astrochemical studies. the observation of various unidentified lines around 72.2 ghz in the cold dark cloud l483 motivated the search and successful detection of additional groups of lines in ... | interstellar detection of the simplest aminocarbyne h2nc: an ignored but abundant molecule |
we derive a general formalism for interferometric visibilities, which considers first-order antenna-antenna coupling and assumes steady-state, incident radiation. we simulate such coupling features for non-polarized skies on a compact, redundantly spaced array and present a phenomenological analysis of the coupling fea... | array element coupling in radio interferometry i: a semi-analytic approach |
tidal disruption events (tdes) occur when a star passes close enough to a galaxy's supermassive black hole to be disrupted by tidal forces. we discuss new observations of igrj12580+0134, a tde observed in ngc 4845 (d = 17 mpc) in 2010 november, with the karl g. jansky very large array (vla 9 9 the national radio astron... | light-curve evolution of the nearest tidal disruption event: a late-time, radio-only flare |
mm-wave emission from active galactic nuclei (agns) may hold the key to understanding the physical origin of their radio cores. the correlation between radio/mm and x-ray luminosity may suggest a similar physical origin of the two sources. since synchrotron self-absorption decreases with frequency, mm-waves probe small... | the mm-wave compact component of an agn |
zonal (latitudinal) winds dominate the bulk flow of planetary atmospheres. for gas giant planets such as jupiter, the motion of clouds can be compared with radio emissions from the magnetosphere, which is connected to the planet’s interior, to determine the wind speed. in principle, this technique can be applied to bro... | a measurement of the wind speed on a brown dwarf |
the proper motions of the three stars ejected from orion's omc1 cloud core are combined with the requirement that their center of mass is gravitationally bound to omc1 to show that radio source i (src i) is likely to have a mass around 15 m⊙ consistent with recent measurements. src i, the star with the smallest proper ... | the orion protostellar explosion and runaway stars revisited: stellar masses, disk retention, and an outflow from the becklin-neugebauer object |
we present two new epochs of hubble space telescope (hst) space telescope imaging spectrograph coronagraphic imaging, along with multi-epoch optical, near-ir, and radio monitoring, of the hd 163296 system. we find that ansae features identified in earlier-epoch hst imagery are a fourth ring that resides at a semimajor ... | disk illumination and jet variability of the herbig ae star hd 163296 using multi-epoch hst/stis optical, near-ir, and radio imagery and spectroscopy |
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