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the next generation very large array (ngvla) is a transformational radio observatory being designed by the u.s. national radio astronomy observatory (nrao). it will provide order of magnitude improvements in sensitivity, resolution, and uv coverage over the current jansky very large array (vla) at ~1.2-50 ghz and exten... | the next generation very large array |
we present a concept of a millimeter wavefront sensor that allows real-time sensing of the surface of a groundbased millimeter/submillimeter telescope. it is becoming important for ground-based millimeter/submillimeter astronomy to make telescopes larger with keeping their surface accurate. to establish `millimetric ad... | wavefront sensor for millimeter/submillimeter-wave adaptive optics based on aperture-plane interferometry |
precision measurement of the beam pattern of an antenna is very important for many applications. while traditionally such measurement is often made in a microwave anechoic chamber or at a test range, measurement using an unmanned aerial vehicle offers a number of advantages: the measurement can be made for the assemble... | beam measurements of the tianlai dish radio telescope using an unmanned aerial vehicle [antenna applications corner] |
there are only a few very-high-energy sources in our galaxy that might accelerate particles up to the knee of the cosmic-ray spectrum. to understand the mechanisms of particle acceleration in these pevatron candidates, fermi-large area telescope (lat) and high-energy stereoscopic system (h.e.s.s.) observations are esse... | constraining the origin of the puzzling source hess j1640-465 and the pevatron candidate hess j1641-463 using fermi-large area telescope observations |
the phenomenon of pulsar nulling, observed as the temporary inactivity of a pulsar, remains poorly understood both observationally and theoretically. most observational studies that quantify nulling employ a variant of ritchings algorithm, which can suffer significant biases for pulsars where the emission is weak. usin... | a pilot study of nulling in 22 pulsars using mixture modeling |
based on a new h i survey using the five-hundred-meter aperture spherical radio telescope (fast), combined with the pan-starrs1 images, we identified an isolated h i cloud without any optical counterpart, named fast j0139+4328. the newly discovered h i cloud appears to be a typical disk galaxy since it has a double-pea... | discovery of an isolated dark dwarf galaxy in the nearby universe |
fast radio bursts (frbs) are highly energetic transient events with duration of order of microseconds to milliseconds and of unknown origin. they are known to lie at cosmological distances, through localization to host galaxies. recently, an frb-like event was seen from the milky way magnetar sgr 1935+2154 by the chime... | detecting fast radio bursts in the milky way |
magnetars form a special population of neutron stars with strong magnetic fields and long spin periods. about 30 magnetars and magnetar candidates known currently are probably isolated, but the possibility that magnetars are in binaries has not been excluded. in this work, we perform spin evolution of neutron stars wit... | are there magnetars in high-mass x-ray binaries? |
the dichotomy between radio-loud (rl) and radio-quiet (rq) active galactic nuclei (agns) is thought to be intrinsically related to radio jet production. this difference may be explained by the presence of a strong magnetic field (b-field) that enhances, or is the cause of, the accretion activity and the jet power. here... | on the origin of radio-loudness in active galactic nuclei using far-infrared polarimetric observations |
modern studies of solar radio emission are complicated by continuous power amplification and multifrequency external interference, which often completely overlap important frequency ranges. many topical problems in solar radio astronomy require large effective areas of radio telescopes, high frequency and time resoluti... | spectroradiometry of the solar corona on the ratan-600 |
we present a bottom-up calculation of the flux of ultrahigh-energy cosmic rays (uhecrs) and high-energy neutrinos produced by powerful jets of active galactic nuclei (agns). by propagating test particles in 3d relativistic magnetohydrodynamic jet simulations, including a monte carlo treatment of sub-grid pitch-angle sc... | high-energy neutrino emission from espresso-reaccelerated ions in jets of active galactic nuclei |
the polish fireball network (pfn) is a project to monitor regularly the sky over poland in order to detect bright fireballs. in 2016 the pfn consisted of 36 continuously active stations with 57 sensitive analogue video cameras and 7 high resolution digital cameras. in our observations we also use spectroscopic and radi... | current status of polish fireball network |
we present 43 ghz vla spectra for 51 agb sources with the goal of verifying an infrared (ir) color cut intended to separate carbon-rich (c) and oxygen-rich (o) agb sources throughout the galaxy. the color cut is a simple line in the [ks] - [a] versus [a] - [e] color-color diagram based on 2mass and msx photometry, and ... | infrared color separation between thin-shelled oxygen-rich and carbon-rich agb stars |
we present the radio properties of 66 spectroscopically confirmed normal star-forming galaxies (sfgs) at 4.4 < z < 5.9 in the cosmos field that were [c ii]-detected in the atacama large millimeter/submillimeter array large program to investigate [c ii] at early times (alpine). we separate these galaxies ("c ii-de... | the alpine-alma [c ii] survey: the infrared-radio correlation and active galactic nucleus fraction of star-forming galaxies at z 4.4-5.9 |
the international very-long-baseline interferometry service for geodesy and astrometry's int01 sessions originally observed small sets of strong quasars ("sources"). but the sources were unevenly distributed, causing bad observation coverage and high ut1 formal errors at times of the year, especially early october. to ... | balancing source strength and sky coverage in ivs-int01 scheduling |
cryogenic low-noise amplifiers based on high electron mobility transistors (hemts) are widely used in applications such as radio astronomy, deep space communications, and quantum computing. consequently, the physical mechanisms governing the microwave noise figure are of practical interest. in particular, the magnitude... | characterization of self-heating in cryogenic high electron mobility transistors using schottky thermometry |
we have developed a digital fast fourier transform spectrometer made of an analog-to-digital converter (adc) and a field-programmable gate array (fpga). the base instrument has independent adc and fpga modules, which allow us to implement different spectrometers in a relatively easy manner. two types of spectrometers h... | octad-s: digital fast fourier transform spectrometers by fpga |
the experimentally measured radiative lifetimes and branching ratios were combined to determine the transition dipole moments for the b2σ+(v = 0-3) → x2σ+(v = 0-6) bands of aluminum monoxide, alo, and compared with theoretical predictions. the b2σ+-x2σ+ (0, 1) band of a molecular beam sample of alo was recorded at high... | the stark effect, zeeman effect, and transition dipole moments for the b2σ+-x2σ+ band of aluminum monoxide, alo |
the sardinia radio telescope (srt) is a new facility managed by the italian national institute for astrophysics (inaf). srt will detect the extremely faint radio wave signals emitted by astronomical objects in a wide frequency range from decimeter to millimeter wavelengths. especially at high frequencies (>10 ghz), ... | an atmosphere monitoring system for the sardinia radio telescope |
we propose a parity-baseline segmented planar imaging method with more frequency components by changing different baseline selection to achieve better imaging in the rotational process. a theoretical model of the parity-baseline segmented planar imaging system with rotational operation is built to analyze the imaging e... | optimal design of segmented planar imaging system based on rotation and clean algorithm |
during 2016 february, csiro astronomy and space science and the max-planck-institute for radio astronomy installed, commissioned, and carried out science observations with a phased array feed receiver system on the 64-m diameter parkes radio telescope. here, we demonstrate that the phased array feed can be used for pul... | observing pulsars with a phased array feed at the parkes telescope |
radio frequency interference (rfi) is an important challenge in radio astronomy. rfi comes from various sources and increasingly impacts astronomical observation as telescopes become more sensitive. in this study, we propose a fast and effective method for removing rfi in pulsar data. we use pseudo-inverse learning to ... | radio frequency interference mitigation using pseudoinverse learning autoencoders |
in this paper, we report our investigation of pulsar scintillation phenomena by monitoring psr b0355+54 at 2.25 ghz for three successive months using the kunming 40-m radio telescope. we measured the dynamic spectrum, the two-dimensional correlation function and the secondary spectrum. these observations have a high si... | interstellar scintillation observations for psr b0355+54 |
we report 3 mm continuum, ch3cn(5-4) and 13cs(2-1) line observations with carma (combined array for research in millimeter-wave astronomy), in conjunction with 6 and 1.3 cm continuum vla data, and 12 and 25 μm broadband data from the subaru telescope toward the massive proto-star iras 18566+0408. the vla data resolve t... | high-resolution observations of the massive protostar in iras 18566+0408 |
in young sun-like stars and field m-dwarf stars, chromospheric and coronal magnetic activity indicators such as hα, x-ray, and radio emission are known to saturate with low rossby number (ro ≲ 0.1), defined as the ratio of rotation period to convective turnover time. the mechanism for the saturation is unclear. in this... | magnetic inflation and stellar mass. v. intensification and saturation of m-dwarf absorption lines with rossby number |
millimeter-wavelength polarimetry of accreting black hole systems can provide a tomographic probe of the accretion flow on a wide range of linear scales. we searched for linear polarization in two low-luminosity active galactic nuclei (llagns), m81 and m84, using the combined array for millimeter astronomy and the subm... | what is the hidden depolarization mechanism in low-luminosity agns? |
methyl mercaptan (also known as methanethiol), ch3sh, has been found in the warm and dense parts of high- as well as low- mass star-forming regions. the aim of the present study is to obtain accurate spectroscopic parameters of the s-deuterated methyl mercaptan ch3sd to facilitate astronomical observations by radio tel... | deuterated methyl mercaptan (ch3sd): laboratory rotational spectroscopy and search toward iras 16293-2422 b |
radio emission from stars can be used, for example, to study ionized winds or stellar flares. the radio emission is faint and studies have been limited to few objects. the square kilometer array (ska) brings a survey ability to the topic of radio stars. in this paper we investigate what the ska can detect, and what sen... | radio stars of the ska |
the 1974 discovery, by russell a hulse and joseph h taylor, of the first binary pulsar, psr b1913+16, opened up new possibilities for the study of relativistic gravity. psr b1913+16, as well as several other binary pulsars, provided direct observational proof that gravity propagates at the velocity of light and has a q... | 1974: the discovery of the first binary pulsar |
we report the discovery of several energetic radio bursts at 34 mhz, using the gauribidanur radio telescope. the radio bursts exhibit two important properties associated with the propagation of astronomical signals through the interstellar medium: (i) frequency dependent dispersive delays across the observing bandwidth... | discovery of low dm fast radio transients: geminga pulsar caught in the act |
we present 2.1 ghz imaging with the australia telescope compact array (atca) of a 6.5 deg2 region within the xxm-newton xxl south field using a band of 1.1-3.1 ghz. we achieve an angular resolution of 4.7'' × 4.2'' in the final radio continuum map with a median rms noise level of 50 μjy/beam. we identify 1389 radio sou... | the xxl survey. xi. atca 2.1 ghz continuum observations |
previous radio observations revealed widespread gas-phase methanol (ch3oh) in the central molecular zone (cmz) at the galactic center (gc), but its origin remains unclear. here, we report the discovery of ch3oh ice toward a star in the cmz, based on a subaru 3.4-4.0 μm spectrum, aided by nasa/irtf l\prime imaging and 2... | abundant methanol ice toward a massive young stellar object in the central molecular zone |
india's largest 3.6 m aperture optical telescope has been successfully installed in the central himalayan region at devasthal, nainital district, uttarakhand. the primary mirror of the telescope uses the active optics technology. the back-end instruments, enabling spectroscopic and photometric imaging of the celestial ... | scientific capabilities and advantages of the 3.6 meter optical telescope at devasthal, uttarakhand |
the rotational spectra of thioisocyanic acid (hncs), and its three energetic isomers (hscn, hcns, and hsnc) have been observed at high spectral resolution by a combination of chirped-pulse and fabry-pérot fourier-transform microwave spectroscopy between 6 and 40~ghz in a pulsed-jet discharge expansion. two isomers, thi... | molecular polymorphism: microwave spectra, equilibrium structures, and an astronomical investigation of the hncs isomeric family |
we present the results of our investigations into options for the computing platform for the imaging pipeline in the chiles project, an ultra-deep hi pathfinder for the era of the square kilometre array. chiles pushes the current computing infrastructure to its limits and understanding how to deliver the images from th... | imaging ska-scale data in three different computing environments |
the volume of data from current and future observatories has motivated the increased development and application of automated machine learning methodologies for astronomy. however, less attention has been given to the production of standardized data sets for assessing the performance of different machine learning algor... | mirabest: a data set of morphologically classified radio galaxies for machine learning |
we present analysis of the rate of giant radio pulses (gps) emission from the crab pulsar (b0531+21). results of our 9 years daily observations with the large phased array radio telescope of pushchino radio astronomy observatory at 111 mhz were used. limited sample of 8753 strong individual pulses in 2004 observational... | irregularities in the rate of generation of giant pulses from the crab pulsar observed at 111 mhz |
calibrating for direction-dependent ionospheric distortions in visibility data is one of the main technical challenges that must be overcome to advance low-frequency radio astronomy. in this paper, we propose a novel probabilistic, tomographic approach that utilises gaussian processes to calibrate direction-dependent i... | a probabilistic approach to direction-dependent ionospheric calibration |
photometric surveys have provided incredible amounts of astronomical information in the form of images. however, astronomical images often contain artifacts that can critically hinder scientific analysis by misrepresenting intensities or contaminating catalogs as artificial objects. these affected pixels need to be mas... | a method for unmasking incomplete astronomical signals: application to the co multi-line imaging of nearby galaxies project |
a statistical framework is presented for the study of the orthogonally polarized modes of radio pulsar emission via the covariances between the stokes parameters. to accommodate the typically heavy-tailed distributions of single-pulse radio flux density, the fourth-order joint cumulants of the electric field are used t... | the statistics of radio astronomical polarimetry: disjoint, superposed, and composite samples |
recently, fast radio bursts (frbs) have become a thriving field in astronomy and cosmology. due to their extragalactic and cosmological origin, they are useful to study the cosmic expansion and the intergalactic medium (igm). in the literature, the dispersion measure dm of frb has been considered extensively. it could ... | could fast radio bursts be standard candles? |
in this paper we introduce a new python package, the pulsar signal simulator, or psrsigsim, which is designed to simulate a pulsar signal from emission at the pulsar, through the interstellar medium, to observation by a radio telescope, and digitization in a standard data format. we use psrsigsim to simulate observatio... | a study in frequency-dependent effects on precision pulsar timing parameters with the pulsar signal simulator |
we report the most detailed 1-3 ghz radio continuum emission map of the nearest region of massive-star formation, the carina nebula. as part of a large program with the australia telescope compact array, we have covered ∼12 deg2, achieving an angular resolution of ∼16″, representing the largest and most complete map of... | the carina nebula and gum 31 molecular complex. iii. the distribution of the 1-3 ghz radio continuum across the whole nebula |
we report the discovery of two kinematically anomalous atomic hydrogen (h i) clouds in m 100 (ngc 4321), which was observed as part of the deciphering the interplay between the interstellar medium, stars, and the circumgalactic medium (diisc) survey in h i 21 cm at 3.3 km s-1 spectroscopic and 44″ × 30″ spatial resolut... | diisc-i: the discovery of kinematically anomalous h i clouds in m 100 |
magnetar hyperflares are the most plausible explanation for fast radio bursts (frbs)-enigmatic powerful radio pulses with durations of several milliseconds and high brightness temperatures. the first observational evidence for this scenario was obtained in 2020 april when an frb was detected from the direction of the g... | searching for tev gamma-ray emission from sgr 1935+2154 during its 2020 x-ray and radio bursting phase |
the rotational line survey by alma (atacama large millimeter/submillimeter array) recently revealed the presence of i-c3h7cn (i-prcn) and n-c3h7cn (n-prcn) in 3-mm atmospheric window between 84 to 111 ghz towards the hot core region sagittarius b2(n) (sgr b2(n)). this was the first interstellar detection of a linear st... | a comprehensive rotational study of astronomical iso-pentane within 84 to 111 ghz |
a sensitive (1σ rms ≤ 3 mk) 1 mm spectral survey (214.5-285.5 ghz) of the oxygen-rich circumstellar envelope of the red hypergiant nml cygni (nml cyg) has been conducted using the sub-millimeter telescope (smt) of the arizona radio observatory (aro). over 100 spectral lines were detected, arising from 17 different mole... | molecules and outflows in nml cygni: new insights from a 1 mm spectral line survey |
we present the first catalog of supernova remnants (snrs) in m31 that exhibit diffuse ultraviolet (uv) emission. uv images of m31 were obtained by the ultraviolet imaging telescope (uvit) on the astrosat satellite, and the list of snrs was obtained from x-ray, optical, and radio catalogs of snrs in m31. we used the uvi... | discovery of 20 uv-emitting snrs in m31 with uvit |
particle cascades induced by ultra-high-energy (uhe) cosmic rays and neutrinos impacting on the lunar regolith usually radiate cherenkov radio emissions due to the presence of excess negative charge, which is known as askaryan effect. several experiments have been carried out to detect the cherenkov radio emissions in ... | detection of ultra high energy cosmic rays and neutrinos with lunar orbital radio telescope |
infrared observations of stellar orbits about sgr a* probe the mass distribution in the inner parsec of the galaxy and provide definitive evidence for the existence of a massive black hole. however, the infrared astrometry is relative and is tied to the radio emission from sgr a* using stellar sio masers that coincide ... | an updated reference frame for the galactic inner parsec |
the true nature of sources of cosmic neutrinos recorded by the antarctic icecube neutrino detector is still an enigma of high-energy astrophysics. time-integrated neutrino source searches with the 10 years of icecube data unfolded neutrino hot-spots of the sky; among them, one is associated with the blazar pks 1424+240... | multiwavelength analysis of the icecube neutrino source candidate blazar pks 1424+240 |
the fourth fermi large area telescope catalog (4fgl) contains 5064 γ-ray sources detected at high significance, but 26% of them still lack associations at other wavelengths. the spt-sz survey, conducted between 2008 and 2011 with the south pole telescope (spt), covers 2500 deg2 of the southern sky in three millimeter-w... | new identifications and multiwavelength properties of extragalactic fermi gamma-ray sources in the spt-sz survey field |
in this work, we examine the robustness of state-of-the-art semi-supervised learning (ssl) algorithms when applied to morphological classification in modern radio astronomy. we test whether ssl can achieve performance comparable to the current supervised state of the art when using many fewer labelled data points and i... | can semi-supervised learning reduce the amount of manual labelling required for effective radio galaxy morphology classification? |
this work utilizes established models of synchrotron-powered light curves for core-collapse supernovae in dense circumstellar environments, namely, type iin and ibn, to demonstrate the potential for detecting millimeter emission from these events. the progenitor types of these supernovae are still an open question, but... | models of millimeter and radio emission from interacting supernovae |
we explore a new, efficient mechanism that can power toroidally magnetized jets up to two to three times their original terminal velocity after they enter a self-similar phase of magnetic acceleration. underneath the elongated outflow lobe formed by a magnetized bubble, a wide-angle free wind, through the interplay wit... | a unified model for bipolar outflows from young stars: apparent magnetic jet acceleration |
a far-infrared counterpart to the west hot spot of the radio galaxy pictor a is discovered with the spectral and photometric imaging receiver (spire) on board herschel. the color-corrected flux density of the source is measured as 70.0 ± 9.9 mjy at the wavelength of 350 μm. a close investigation into its radio-to-optic... | herschel spire discovery of far-infrared excess synchrotron emission from the west hot spot of the radio galaxy pictor a |
a strong coronal magnetic field, when present, manifests itself as bright microwave sources at high frequencies produced by the gyroresonant (gr) emission mechanism in thermal coronal plasma. the highest frequency at which this emission is observed is proportional to the absolute value of the strongest coronal magnetic... | strongest coronal magnetic fields in solar cycles 23 and 24: probing, statistics, and implications |
fast radio bursts (frbs) are still a mystery in contemporary astrophysics. unlike many other astronomical objects whose basic physical mechanism is already identified and the research on which focuses mainly on refining details, frbs are still largely unknown regarding their source(s) and radiation mechanism(s). to mak... | solving the mystery of fast radio bursts: a detective's approach |
we present the serendipitous detection of a new galactic supernova remnant (snr), g288.8-6.3, using data from the australian square kilometre array pathfinder (askap) evolutionary map of the universe (emu) survey. using multifrequency analysis, we confirm this object as an evolved galactic snr at high galactic latitude... | emu detection of a large and low surface brightness galactic snr g288.8-6.3 |
astronomers at the mizusawa very long baseline interferometry observatory of the national astronomical observatory of japan are promoting the development of broadband receivers in the ultra-high frequency (uhf) band. the presence of extensive radio frequency interferences (rfi) in the uhf band hinders continuous broadb... | development of highly selective compact high-temperature superconducting quad-band bandpass filter using interdigital feeding structure for radio astronomy |
waves propagating near an event horizon display interesting features including logarithmic phase singularities and caustics. we consider an acoustic horizon in a flowing bose-einstein condensate where the elementary excitations obey the bogoliubov dispersion relation. in the hamiltonian ray theory the solutions undergo... | logarithmic catastrophes and stokes's phenomenon in waves at horizons |
this work presents a software-defined radio ionosonde (isdr) developed at the abdus salam international centre for theoretical physics (italy) and the institute of radio astronomy (ukraine) and installed at the ukrainian antarctic station in 2017. for the first time, the results of the long-term data comparison of the ... | performance analysis of a portable low-cost sdr-based ionosonde |
spectroscopy in the mm/sub-mm wavelength range is a powerful tool to study the gaseous medium in various astrophysical environments. the next generation event horizon telescope (ngeht) equipped with a wide-bandwidth backend system has great potential for science using high angular resolution spectroscopy. spectral line... | spectral line vlbi studies using the ngeht |
a new method is described to establish the pointing model of the 65-meter radio telescope of shanghai astronomical observatory (tm65 m). the prediction of source orbit is used to improve efficiency. the single pointing error is collected via ``cross scan'', and the model is fitted with both the gaussian and nonlinear t... | pointing model establishment of tm65 m radio telescope |
we present five-year monitoring results of 225 ghz zenith opacity using a tipping radiometer at thule air base (pituffik), greenland, where the greenland telescope is currently located. the site shows a clear seasonal variation with average opacity lower by a factor of two during winter compared with summer, similar to... | five-year monitoring of 225 ghz opacity at thule air base (pituffik), greenland |
the australian square kilometre array pathfinder (askap) will be the fastest dedicated cm-wave survey telescope, and will consist of 36 12-meter 3-axis antennas, each with a large chequerboard phased array feed (paf) receiver operating between 0.7 and 1.8 ghz, and digital beamforming prior to correlation. the large raw... | the australian ska pathfinder: project update and initial operations |
with the discovery and utilization of great observation sites, on-ground radio astronomical observations have been extended from the millimeter-wave (mm-wave) range to around 1.6 thz. the radiation collected by the telescope reflector antenna is coupled to the receiver by means of the receiver optics. these optics must... | reconfigurable near-field beam pattern measurement system from 0.03 to 1.6 thz |
a new waveguide stepped septum-type circular polarizer (sst-cp) was developed to operate in the 500-ghz band for radio astronomical and planetary atmospheric observations. in a previous study, we developed a practical sst-cp for the 230-ghz band. however, several issues prevent this device being easily scaled down to t... | novel 500-ghz band waveguide stepped septum-type circular polarizer with a new high-accuracy and very small waveguide flange |
we present timing solutions of psr b0950+08, using 14 years of observations from the nanshan 26-m radio telescope of xinjiang astronomical observatory. the braking index of psr b0950+08 varies from -367 392 to 168 883, which shows an oscillation with large amplitude (~105) and uncertainty. considering the variation of ... | timing and evolution of psr b0950+08 |
in this work, we perform molecular dynamic (md) simulations to investigate the stability and fragmentation processes of vibrationally excited linear polycyclic aromatic hydrocarbons (pahs). the program of cp2k in combination with the semi-empirical method pm3 is utilized for the md simulations. the simulations show tha... | formation of polyynes and ring-polyyne molecules following fragmentation of polycyclic aromatic hydrocarbons |
differential phase delay is calculated for the differential one-way range (dor) signals transmitted by tianwen-1, the first chinese mars spacecraft that entered into the mars orbit on 2021 february 10. large decreases in the differential phase delay are identified in the dor signals received by ground stations on 2021 ... | cme-related large decreases in the differential phase delay of tianwen-1 dor signals |
the magnetosphere of, and electromagnetic (em) radiation from pulsars are usually described in the framework of classical electrodynamics. for some pulsars, however, whose emission heights are relatively close to the surface of the neutron star, general relativistic effects might modify the emission from the pulsar. we... | general relativistic effects on pulsar radiation |
aims: we study the meteoroid stream of the long-period comet c/1963 a1 (ikeya) to predict the meteor showers originating in this comet. we also aim to identify the predicted showers with their real counterparts.methods: we modeled 23 parts of a theoretical meteoroid stream of the parent comet considered. each of our mo... | long-period comet c/1963 a1 (ikeya), the probable parent body of π-hydrids, δ-corvids, november α-sextantids, and ϑ-leonids |
context. the acetaldehyde molecule is ubiquitous in the interstellar medium of our galaxy, and due to its dense and complex spectrum, large dipole moment, and several low-lying torsional states, acetaldehyde is considered to be a "weed" molecule for radio astronomy observations. mono-13c acetaldehydes 13ch3cho and ch31... | millimeter and submillimeter wave spectra of mono-13c-acetaldehydes |
the chime pathfinder is a new interferometric radio telescope that uses a hybrid fpga/gpu fx correlator. the gpu-based x-engine of this correlator processes over 819 gb/s of 4+4-bit complex astronomical data from n=256 inputs across a 400 mhz radio band. a software framework is presented to manage this real-time data f... | an efficient real-time data pipeline for the chime pathfinder radio telescope x-engine |
radio astronomical observations below 30 mhz are hampered by the refraction and absorption of the ionosphere as well as the radio frequency interference (rfi), and thus, high angular resolution sky intensity map is not yet available. an interferometer array on lunar orbit provides a perfect observatory in this frequenc... | an imaging algorithm for a lunar orbit interferometer array |
the second realization of the international celestial reference frame (icrf2), which is the current fundamental celestial reference frame adopted by the international astronomical union, is based on very long baseline interferometry (vlbi) data at radio frequencies in x band and s band. the european space agency’s gaia... | ivs observation of icrf2-gaia transfer sources |
we study the anomalous microwave emission (ame) in the lynds dark nebula (ldn) 1780 on two angular scales. with publicly available data at an angular resolution of 1°, we studied the spectral energy distribution of the cloud in the 0.408-2997 ghz frequency range. the cloud presents a significant (>20σ) amount of ame... | modelling the spinning dust emission from ldn 1780 |
we present the results of our systematic search for the reddest far-infrared (fir) and submillimeter (sub-mm) galaxies using the data from the herschel multi-tiered extragalactic survey (hermes) and the scuba2 cosmological legacy survey (s2cls). the red fir galaxies are "500 μm risers," whose spectral energy distributi... | a systematic search for the reddest far-infrared and submillimeter galaxies: revealing dust-embedded starbursts at high redshifts |
the detection of non-repeating events in the radio spectrum has become an important area of study in radio astronomy over the last decade due to the discovery of fast radio bursts (frbs). we have implemented a single pulse detection algorithm, for nvidia gpus, which use boxcar filters of varying widths. our code perfor... | a real-time single pulse detection algorithm for gpus |
we report observations of co(j = 2 → 1) and {co}(j=3\to 2) line emission toward the quadruply-lensed quasar rxs j1131-1231 at z = 0.654 obtained using the plateau de bure interferometer (pdbi) and the combined array for research in millimeter-wave astronomy (carma). our lens modeling shows that the asymmetry in the dou... | molecular gas kinematics and star formation properties of the strongly-lensed quasar host galaxy rxs j1131-1231 |
as the canadian hydrogen intensity mapping experiment (chime) has become the leading instrument for detecting fast radio bursts (frbs), chime/frb outriggers will use very-long-baseline interferometry (vlbi) to localize frbs with milliarcsecond precision. the chime site uses a passive hydrogen maser frequency standard i... | evaluating and enhancing candidate clocking systems for chime/frb vlbi outriggers |
we have developed a new technique called direct shear mapping (dsm) to measure gravitational lensing shear directly from observations of a single background source. the technique assumes the velocity map of an unlensed, stably rotating galaxy will be rotationally symmetric. lensing distorts the velocity map making it a... | direct shear mapping - a new weak lensing tool |
magnetospheric observational proxies are used for indirect detection of magnetic fields in hot stars in the x-ray, uv, optical, and radio wavelength ranges. to determine the viability of infrared (ir) hydrogen recombination lines as a magnetic diagnostic for these stars, we have obtained low-resolution (r~ 1200), near-... | an infrared diagnostic for magnetism in hot stars |
we study the nearby lenticular galaxy ngc 3998. this galaxy is known to host a low-power radio agn with a kpc-size one-sided jet and a large, nearly polar h i disc. it is therefore a good system to study to understand the relation between the availability of cold-gas and the triggering of agns in galaxies. our new wsrt... | a rare example of low surface-brightness radio lobes in a gas-rich early-type galaxy: the story of ngc 3998 |
this paper presents the results of a search for neutrinos that are spatially and temporally coincident with 22 unique, nonrepeating fast radio bursts (frbs) and one repeating frb (frb 121102). frbs are a rapidly growing class of galactic and extragalactic astrophysical objects that are considered a potential source of ... | a search for coincident neutrino emission from fast radio bursts with seven years of icecube cascade events |
psr j1101-6101 is an energetic young pulsar that powers the remarkable lighthouse pulsar wind nebula (pwn). the pulsar belongs to the rare type of radio- and gamma-ray-quiet pulsars that are bright in hard x-rays. moreover, the lighthouse pwn is remarkable for its misaligned outflow (which gave rise to the pwn's nickna... | a nustar and chandra investigation of the misaligned outflow of psr j1101-6101 and the lighthouse pulsar wind nebula |
ngc 3718 is a low-ionization nuclear emission line region (liner) l1.9 galaxy, lying at a distance of about ~17.4 mpc from the earth; its similarities with ngc 5128 often award it the name northern centaurus a. the presence of a compact radio source with a candidate jet structure, a prominent dust lane, and a strongly ... | subaru and e-merlin observations of ngc 3718. diaries of a supermassive black hole recoil? |
polarization measurements of gamma-ray burst (grb) afterglows are a promising means of probing the structure, geometry, and magnetic composition of relativistic grb jets. however, a precise treatment of instrumental calibration is vital for a robust physical interpretation of polarization data, requiring tests of and v... | radio linear polarization of grb afterglows: instrumental systematics in alma observations of grb 171205a |
the balloon-borne hical radio-frequency (rf) transmitter, in concert with the anita radio-frequency receiver array, is designed to measure the antarctic surface reflectivity in the rf wavelength regime. the amplitude of surface-reflected transmissions from hical, registered as triggered events by anita, can be compared... | antarctic surface reflectivity calculations and measurements from the anita-4 and hical-2 experiments |
as a dedicated solar radio interferometer, the mingantu spectral radioheliograph (muser) generates massive observational data in the frequency range of 400 mhz-15 ghz. high-performance imaging forms a significantly important aspect of muser’s massive data processing requirements. in this study, we implement a practical... | gpu-based high-performance imaging for mingantu spectral radioheliograph |
we present a laboratory rotational study of, and astronomical search for, lactaldehyde (ch3ch(oh)ch(o)), one of the simplest chiral molecules that could reasonably be seen in the interstellar medium (ism), in the millimeter and submillimeter wave regions from 80 to 460 ghz. more than 5000 transitions were assigned to t... | the laboratory millimeter and submillimeter rotational spectrum of lactaldehyde and an astronomical search in sgr b2(n), orion-kl, and ngc 6334i |
the tianlai project is a 21 cm intensity mapping experiment aimed at detecting dark energy by measuring the baryon acoustic oscillation (bao) features in the large scale structure power spectrum. this experiment provides an opportunity to test the data processing methods for cosmological 21 cm signal extraction, which ... | data processing pipeline for tianlai experiment |
solar radio type ii bursts serve as early indicators of incoming geo-effective space weather events such as coronal mass ejections (cmes). in order to investigate the origin of high-frequency type ii bursts (hf type ii bursts), we have identified 51 of them (among 180 type ii bursts from swpc reports) that are observed... | trends and characteristics of high-frequency type ii bursts detected by callisto spectrometers |
steady-state superradiance and superradiant lasing attract significant attentions in the field of optical lattice clocks, but have not been achieved so far due to the technical challenges and atom loss problem. in this article, we propose that their counter-part may be observed in the microwave domain with solid-state ... | superradiant masing with solid-state spins at room temperature |
astrometry at centimeter wavelengths using very long baseline interferometry is approaching accuracies of ~1 μas for the angle between a target and a calibrator source separated by ≲1° on the sky. the bessel survey and the japanese vera project are using this to map the spiral structure of the milky way by measuring tr... | techniques for measuring parallax and proper motion with vlbi |
data challenges are emerging as powerful tools with which to answer fundamental astronomical questions. time-domain astronomy lends itself to data challenges, particularly in the era of classification and anomaly detection. with improved sensitivity of wide-field surveys in optical and radio wavelengths from surveys li... | data challenges as a tool for time-domain astronomy |
we present a brief description of a joint russian-korean project abbreviated as explanation (exoplanet and transient events investigation). the project is aimed at a massive photometric, speckle-interferometric, spectral, and radio bolometric search for non-stationary events in the universe, as well as the study of exo... | explanation: exoplanet and transient events investigation project |
phosphaketene, hpco, and silaisocyanic acid, hnsio, have been characterized in the gas phase for the first time, employing fourier transform microwave spectroscopy. besides the parent isotopic species, the rare isotopologs hp13co, hn29sio, and hn30sio were also observed. the molecular parameters derived experimentally ... | phosphorus and silicon analogs of isocyanic acid: microwave detection of hpco and hnsio |
in this article we update constraints on superconducting cosmic strings (scss) in the light of the recent observational developments of fast radio bursts (frbs) astronomy. assuming strings follow an exponential distribution characterized by a current, we show that two parameters in our context, which are the characteri... | updated constraints on superconducting cosmic strings from the astronomy of fast radio bursts |
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