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fast radio bursts (frbs) are a promising new probe for astronomy and cosmology. thanks to their extragalactic and cosmological origin, frbs could be used to study the intergalactic medium (igm) and the cosmic expansion. it is expected that numerous frbs with identified redshifts will be available in the near future thr... | reconstructing the fraction of baryons in the intergalactic medium with fast radio bursts via gaussian processes |
we search for a spatial association between radio pulsars and ultra-high energy neutrinos using the publicly available icecube point source neutrino events catalog. for this purpose we use the unbinned maximum likelihood method to search for a statistically significant excess from each of the pulsars in the atnf catalo... | search for spatial coincidence between icecube neutrinos and radio pulsars |
we present decoras, a deep-learning-based approach to detect both point and extended sources from very long baseline interferometry (vlbi) observations. our approach is based on an encoder-decoder neural network architecture that uses a low number of convolutional layers to provide a scalable solution for source detect... | decoras: detection and characterization of radio-astronomical sources using deep learning |
the results of a study of the maser source iras 18316-0602 in the h2o line at λ = 1.35 cm are reported. the observations were carried out on the 22-m radio telescope of the pushchino radio astronomy observatory (russia) from june 2002 until march 2017. three superflares were detected, in 2002, 2010, and 2016, with peak... | superflares of h2o maser emission toward the protostellar object g25.65+1.05 (iras 18316-0602) |
this white paper summarises potential key science topics to be achieved with thai national radio telescope (tnrt). the commissioning phase has started in mid 2022. the key science topics consist of "pulsars and fast radio bursts (frbs)", "star forming regions (sfrs)", "galaxy and active galactic nuclei (agns)", "evolve... | sciences with thai national radio telescope |
we employ synthetic observations obtained with magnetohydrodynamic simulations to study how to trace the distribution of turbulent magnetic fields using the synchrotron polarization gradient techniques suggested by lazarian & yuen. both synchrotron polarization gradients and its derivative gradients with regard to ... | tracing magnetic field with synchrotron polarization gradients: parameter study |
associating γ-ray sources to their low-energy counterparts is one of the major challenges of modern γ-ray astronomy. in the context of the fourth fermi large area telescope source catalog (4fgl), the associations rely mainly on parameters such as apparent magnitude, integrated flux, and angular separation between the γ... | on the physical association of fermi-lat blazars with their low-energy counterparts |
nanosized silicate dust is likely to be abundant in many astronomical environments and it is a prime candidate for being the source of the anomalous microwave emission (ame). to assess the viability of silicate nanoclusters as ame carriers, their detailed properties need to be established. using quantum chemical calcul... | assessing the viability of silicate nanoclusters as carriers of the anomalous microwave emission: a quantum mechanical study |
ukraine has scientific and technical potential to construct a spacecraft and payloads for exploration of the moon in collaboration with other interested countries. in this paper we propose a double mission that consists of two parts: (1) orbiter exploration from an elongated orbit with a pericenter over the north pole ... | a twofold mission to the moon: objectives and payloads |
a conservative constraint on the rest mass of the photon can be estimated under the assumption that the frequency dependence of dispersion from astronomical sources is mainly contributed by the nonzero photon mass effect. photon mass limits have been set earlier through the optical emissions of the crab nebula pulsar, ... | new limits on the photon mass with radio pulsars in the magellanic clouds |
we present the automated systemfor estimating the parameters of radio sources observed on all available continuum radiometers (two receiving facilities of secondary mirrors no. 1 and no. 2 with a total of 30 radiometers) developed at ratan-600 radio telescope and put into normal operation. the system is also used for t... | automated system for reduction of observational data on ratan-600 radio telescope |
space very long baseline interferometry is a radio astronomy technique distinguished by a record-high angular resolution reaching single-digit microseconds of arc. the paper provides a brief account of the history of developments of this technique over the period 1960s-2020s. | a brief history of space vlbi |
“trao funs” is a project to survey the gould belt’s clouds in molecular lines. this paper presents its first results on the central region of the california molecular cloud, l1478. we performed on-the-fly mapping observations using the taeduk radio astronomy observatory 14 m single-dish telescope equipped with a 16 mul... | trao survey of nearby filamentary molecular clouds, the universal nursery of stars (trao funs). i. dynamics and chemistry of l1478 in the california molecular cloud |
photometric variability attributed to cloud phenomena is common in l/t transition brown dwarfs. recent studies show that such variability may also trace aurorae, suggesting that localized magnetic heating may contribute to observed brown dwarf photometric variability. we assess this potential correlation with a survey ... | on the correlation between l dwarf optical and infrared variability and radio aurorae |
we studied the pc-scale core shift effect using radio light curves for three blazars, s5 0716+714, 3c 279 and bl lacertae, which were monitored at five frequencies (ν) between 4.8 and 36.8 ghz using the university of michigan radio astronomical observatory (umrao), the crimean astrophysical observatory (crao) and metsä... | core shift effect in blazars |
we observed a small sample of five radio-quiet quasars with integral field spectroscopy to search for possible extended emission in the lyα line. we subtracted the quasar point sources using a simple point spread function (psf) self-calibration technique that takes advantage of the simultaneous availability of spatial ... | where is the fuzz? undetected lyman α nebulae around quasars at z ~ 2.3 |
the growing focus on indoor robot navigation utilizing wireless signals has stemmed from the capability of these signals to capture high-resolution angular and temporal measurements. prior heuristic-based methods, based on radio frequency propagation, are intuitive and generalizable across simple scenarios, yet fail to... | zero-shot wireless indoor navigation through physics-informed reinforcement learning |
we present a multi-wavelength polarimetric and spectral study of the m87 jet obtained at sub-arcsecond resolution between 2002 and 2008. the observations include multi-band archival vla polarimetry data sets along with hubble space telescope (hst) imaging polarimetry. these observations have better angular resolution t... | multi-wavelength polarimetry and spectral study of the m87 jet during 2002-2008 |
radio astronomy observatories with high throughput back end instruments require real-time data processing. while computing hardware continues to advance rapidly, development of real-time processing pipelines remains difficult and time-consuming, which can limit scientific productivity. motivated by this, we have develo... | bifrost: a python/c++ framework for high-throughput stream processing in astronomy |
modern large radio continuum surveys have high sensitivity and resolution, and can resolve previously undetected extended and diffuse emissions, which brings great challenges for the detection and morphological classification of extended sources. we present hetu-v2, a deep learning-based source detector that uses the c... | radio sources segmentation and classification with deep learning |
a new high-resolution radio spectropolarimeter instrument operating in the frequency range of 15 - 85 mhz has recently been commissioned at the radio astronomy field station of the indian institute of astrophysics at gauribidanur, 100 km north of bangalore, india. we describe the design and construction of this instrum... | spectropolarimetric observations of solar noise storms at low frequencies |
quenched massive spiral galaxies have attracted great attention recently, as more data are available to constrain their environment and cold gas content. however, the quenching mechanism is still uncertain, as it depends on the mass range and baryon budget of the galaxy. in this letter, we report the identification of ... | what has quenched the massive spiral galaxies? |
with aperture synthesis (as) technique, a number of small antennas can be assembled to form a large telescope whose spatial resolution is determined by the distance of two farthest antennas instead of the diameter of a single-dish antenna. in contrast from a direct imaging system, an as telescope captures the fourier c... | solar image deconvolution by generative adversarial network |
the next generation of imaging atmospheric cherenkov telescope, like cta, is going to strongly improve the detection capability of high-energy cosmic rays. in our paper we discuss the possibility to use such apparatus to detect earth-skimming tau neutrinos. interestingly the analysis shows that order few events per yea... | tau neutrinos with cherenkov telescope array |
mrk 1018 is a nearby changing-look active galactic nucleus (agn) that has oscillated between spectral type 1.9 and type 1 over a period of 40 yr. recently, a recoiling supermassive black hole (rsmbh) scenario has been proposed to explain the spectral and flux variability observed in this agn. detections of rsmbhs are i... | a vlbi proper motion analysis of the recoiling supermassive black hole candidate mrk 1018 |
observations of positional offsets between the location of x-ray and radio features in many resolved, extragalactic jets indicates that the emitting regions are not cospatial, an important piece of evidence in the debate over the origin of the x-ray emission on kiloparsec scales. the existing literature is nearly exclu... | x-ray-to-radio offset inference from low-count x-ray jets |
the arecibo observatory (ao) is a multidisciplinary research and education facility that is recognized worldwide as a leading facility in astronomy, planetary, and atmospheric and space sciences. ao's cornerstone research instrument was the 305-m william e. gordon telescope. on december 1, 2020, the 305-m telescope col... | the future of the arecibo observatory: the next generation arecibo telescope |
the dynamics and the structure of the solar corona are determined by its magnetic field. measuring coronal magnetic fields is, however, extremely hard. the polarization of low-frequency radio emissions has long been recognized as one of the few effective observational probes of magnetic fields in the mid and high coron... | tackling the unique challenges of low-frequency solar polarimetry with the square kilometre array low precursor: pipeline implementation |
the technique of frequency phase transfer (fpt), enabled by multiband receivers with shared optical path (sop), is set to become a true backbone of vlbi operations at frequencies above 22 ghz. the fpt has been successfully implemented at the korean vlbi network (kvn), while gaining ever more prominent attention worldwi... | radio astronomy with multiband receivers and frequency phase transfer: scientific perspectives |
previous observations of the middle-aged γ-ray, x-ray, and radio pulsar b1055-52 indicated some peculiarities, such as a suspected changing of the x-ray flux and spectral parameters, a large excess of the alleged thermal component of the uv spectrum over the rayleigh-jeans extension of the x-ray thermal spectrum, and a... | x-ray and near-infrared observations of the middle-aged pulsar b1055-52, its multiwavelength spectrum, and proper motion |
the variation in the high-energy cutoff, ec , in active galactic nuclei (agns) uniquely probes the corona physics. in this work, we show that the ratio of two nustar spectra (analogous to the difference-imaging technique widely used in astronomy) is uniquely useful in studying ecvariations. the spectra ratio could dire... | on measuring the variation of high-energy cutoff in active galactic nuclei |
we present millimeter, optical, and soft x-ray observations of a stellar flare with an energy squarely in the regime of typical x1 solar flares. the flare was observed from proxima cen on 2019 may 6 as part of a larger multi-wavelength flare monitoring campaign and was captured by chandra, the las cumbres observatory g... | the mouse that squeaked: a small flare from proxima cen observed in the millimeter, optical, and soft x-ray with chandra and alma |
comparisons between the atacama large millimeter/sub-millimeter array (alma) 3mm emission and a range of optical and uv solar observations have found the strongest correspondence between the width of the hydrogen alpha line at 656.3nm and the 3mm brightness temperature. previous studies on the oscillatory power of \pmo... | spatio-temporal comparisons of the hydrogen-alpha line width and alma 3 mm brightness temperature in the weak solar network |
solar energetic particles (seps) are sporadically ejected from the sun during flares and coronal mass ejections. they are of major astrophysical interest, because the proximity of the sun allows for detailed multi-messenger studies. they affect space weather due to interactions with electronics, with the earth's atmosp... | radio astronomical tools for the study of solar energetic particles i. correlations and diagnostics of impulsive acceleration and particle propagation |
txs 0506+056 is a blazar that has been recently identified as the counterpart of the neutrino event icecube-170922a. understanding the blazar type of txs 0506+056 is important to constrain the neutrino emission mechanism, but the blazar nature of txs 0506+056 is still uncertain. as an attempt to understand the nature o... | medium-band observation of the neutrino emitting blazar, txs 0506+056 |
we present the first results of the joint russian-ukrainian experiments for recording of signals from the ekb radar of the institute of solar-terrestrial physics of the siberian branch of the russian academy of sciences (arti observatory of the institute of geophysics of the ural branch of the russian academy of scienc... | bistatic sounding of high-latitude ionospheric irregularities using a decameter ekb radar and an utr-2 radio telescope: first results |
the field of gamma-ray burst astronomy arguably went through three decades of growing pains before reaching maturity. what development lessons can be learned for the adolescent field of fast radio burst astronomy? | from gamma-ray bursts to fast radio bursts |
we present the first survey of radio frequency interference (rfi) at the future site of the low frequency square kilometre array (ska), the murchison radio-astronomy observatory (mro), that both temporally and spatially resolves the rfi. the survey is conducted in a 1 mhz frequency range within the fm band, designed to... | a survey of spatially and temporally resolved radio frequency interference in the fm band at the murchison radio-astronomy observatory |
context. the majority of sulfur-containing molecules detected in the interstellar medium (ism) are analogs of oxygen-containing compounds. propynal was detected in the ism in 1988, hence propynethial, its sulfur derivative, is a good target for an ism search.aims: our aim is to measure the rotational spectrum of propyn... | submillimeter-wave spectroscopy and the radio-astronomical investigation of propynethial (hc≡cchs) |
colliding stellar winds in massive binary systems have been studied through their radio, optical lines and strong x-ray emission for decades. more recently, near-infrared spectro-interferometric observations have become available in a few systems, but isolating the contribution from the individual stars and the wind co... | numerical simulations and infrared spectro-interferometry reveal the wind collision region in γ2 velorum |
the standard imaging algorithm for interferometric radio data, clean, is optimal for point source observations, but suboptimal for diffuse emission. recently, resolve, a new bayesian algorithm has been developed, which is ideal for extended source imaging. unfortunately, resolve is computationally very expensive. in th... | fastresolve: fast bayesian imaging for aperture synthesis in radio astronomy |
signal artifacts due to radio frequency interference (rfi) are a common nuisance in radio astronomy. conventionally, the rfi-affected data are tagged by an expert data analyst in order to warrant data quality. in view of the increasing data rates obtained with interferometric radio telescope arrays, automatic data filt... | detecting radio frequency interference in radio-antenna arrays with the recurrent neural network algorithm |
heterodyne instruments have recently attained quantum-limited low-noise performance, particularly in radio astronomy, but it is difficult to develop large heterodyne arrays such as a modern radio camera using cryogenic sensitive detectors based on microwave kinetic inductance detectors, transition edge sensors, etc. in... | microwave amplification based on quasiparticle sis up and down frequency converters |
we present ztf18aaqjovh (sn 2018bvw), a high-velocity ("broad-lined") stripped-envelope (type ic) supernova (ic-bl sn) discovered in the zwicky transient facility one-day cadence survey. ztf18aaqjovh shares a number of features in common with engine-driven explosions: the photospheric velocity and the shape of the opti... | the broad-lined ic supernova ztf18aaqjovh (sn 2018bvw): an optically discovered engine-driven supernova candidate with luminous radio emission |
we present deep wide-field optical ccd photometry and mid-infrared spitzer/irac and mips 24 μm data for about 100,000 stars in the young open cluster ic 1805. the members of ic 1805 were selected from their location in the various color-color and color-magnitude diagrams, and the presence of hα emission, mid-infrared e... | an optical and infrared photometric study of the young open cluster ic 1805 in the giant h ii region w4 † |
ska precursors are capable of detecting hundreds of galaxies in hi in a single 12 h pointing. in deeper surveys one will probe more easily faint hi structures, typically located in the vicinity of galaxies, such as tails, filaments, and extraplanar gas. the importance of interactive visualization in data exploration ha... | slicerastro: a 3-d interactive visual analytics tool for hi data |
as of 2023, the low-frequency part of the square kilometre array will go online in australia. it will constitute the largest and most powerful low-frequency radio-astronomical observatory to date, and will facilitate a rich science programme in astronomy and astrophysics. with modest engineering changes, it will also b... | ultimate precision in cosmic-ray radio detection — the ska |
extension of radio interferometric baselines into space is inevitable if a diffraction-limited angular resolution defined by the earth diameter at a given observing wavelength limits a pursuit of specific scientific goals. this was understood in the early1960s, at the very dawn of the era of earth-based very long basel... | radio interferometers larger than earth: lessons learned and forward look of space vlbi |
imaging in radio astronomy is usually carried out with a single-dish radio telescope doing a raster scan of a region of the sky or with an interferometer that samples the visibility function of the sky brightness. mosaic observations are the current standard for imaging large fields of view with an interferometer, and ... | a joint deconvolution algorithm to combine single-dish and interferometer data for wideband multiterm and mosaic imaging |
the national radio astronomy observatory's 27 antenna karl g. jansky very large array (nrao vla) has been successfully transitioned to a broadband system. as part of this transition, the us naval research laboratory (nrl) worked with nrao to develop, install, and commission a new commensal low frequency system on the v... | commensal low frequency observing on the nrao vla: vlite status and future plans |
many deep wideband wide-field radio interferometric surveys are being designed to accurately measure intensities, spectral indices, and polarization properties of faint source populations. in this paper, we compare various wideband imaging methods to evaluate the accuracy to which intensities and spectral indices of so... | deep wideband single pointings and mosaics in radio interferometry: how accurately do we reconstruct intensities and spectral indices of faint sources? |
10 new class ii methanol masers from the 6.7-ghz methanol multibeam survey catalogues iii and iv were selected for a monitoring programme at both 6.7 and 12.2 ghz with the 26-m hartebeesthoek radio astronomy observatory radio telescope for 2 yr and 9 months, from 2012 august to 2015 may. in the sample, only masers asso... | discovery of periodic class ii methanol masers associated with g339.986-0.425 region |
we have observed psr b1534+12 (j1537+1155), a pulsar with a neutron star companion, using the five-hundred-meter aperture spherical radio telescope. we found that this pulsar shows two distinct emission states: a weak state with a wide pulse profile and a burst state with a narrow pulse profile. the weak state is alway... | the two emission states of psr b1534+12 |
variability is one of the extreme observational properties of bl lacertae objects. ao 0235+164 is a well-studied bl lac throughout all electromagnetic wavebands. in the present work, we show its optical r-band photometric observations carried out during the period from 2006 november to 2012 december using the ap6e ccd ... | variability and period analysis for bl lac ao 0235+164 |
blazars are among the most studied sources in high-energy astrophysics as they form the largest fraction of extragalactic gamma-ray sources and are considered prime candidates for being the counterparts of high-energy astrophysical neutrinos. their reliable identification amid the many faint radio sources is a crucial ... | deep learning blazar classification based on multifrequency spectral energy distribution data |
casa, the common astronomy software applications package, is the primary data processing software for the atacama large millimeter/submillimeter array (alma) and the karl g. jansky very large array (vla), and is frequently used also for other radio telescopes. the casa software can process data from both single-dish an... | the casa software for radio astronomy: status update from adass 2019 |
as current- and next-generation astronomical instruments come online, they will generate an unprecedented deluge of data. analyzing these data in real time presents unique conceptual and computational challenges, and their long-term storage and archiving is scientifically essential for generating reliable, reproducible... | a real time processing system for big data in astronomy: applications to hera |
we present a methodology for ensuring the robustness of our analysis pipeline in separating the global 21 cm hydrogen cosmology signal from large systematics based on singular value decomposition (svd) of training sets. we show how traditional goodness-of-fit metrics such as the χ2 statistic that assess the fit to the ... | ensuring robustness in training-set-based global 21 cm cosmology analysis |
the development of the atacama large millimeter/submillimeter array (alma) phasing system (aps) has allowed alma to function as an extraordinarily sensitive station for very long baseline interferometry (vlbi) at frequencies of up to 230 ghz (λ ≈ 1.3 mm). efforts are now underway to extend the use of the aps to 345 ghz... | a characterization of the alma phasing system at 345 ghz |
we present apex 218 ghz observations of molecular emission in a complete sample of embedded protostars in the ophiuchus star-forming region. to study the physical properties of the cores, we calculate h2co and c-c3h2 rotational temperatures, both of which are good tracers of the kinetic temperature of the molecular gas... | externally heated protostellar cores in the ophiuchus star-forming region |
in this paper, we report our high-resolution (0.″20 × 0.″14 or ∼70 × 49 pc) observations of the co(6-5) line emission, which probes warm and dense molecular gas, and the 434 μm dust continuum in the nuclear region of ngc 7130, obtained with the atacama large millimeter array (alma). the co line and dust continuum fluxe... | alma imaging of the co (6-5) line emission in ngc 7130* |
the detection of a neutron star merger by the advanced laser interferometer gravitational-wave observatory and advanced virgo gravitational wave detectors, and the subsequent detection of an electromagnetic counterpart have opened a new era of transient astronomy. with upgrades to the advanced laser interferometer grav... | an optimised gravitational wave follow-up strategy with the australian square kilometre array pathfinder |
whilst astronomy as a science is historically founded on observations at optical wavelengths, studying the universe in other bands has yielded remarkable discoveries, from pulsars in the radio, signatures of the big bang at submm wavelengths, through to high energy emission from accreting, gravitationally-compact objec... | paving the way to simultaneous multi-wavelength astronomy |
context. despite the fact that many sulfur-bearing molecules, ranging from simple diatomic species up to astronomical complex molecules, have been detected in the interstellar medium, the sulfur chemistry in space is largely unknown and a depletion in the abundance of s-containing species has been observed in the cold,... | laboratory measurements and astronomical search for the hso radical |
we investigate how to recover the spectral properties of underlying magnetohydrodynamic (mhd) turbulence using fluctuation statistics of synchrotron polarization radiation, based on the synthetic observations. taking spatially coincident, separated, and compounded synchrotron emission and faraday rotation regions into ... | spectral properties of magnetohydrodynamic turbulence revealed by polarization synchrotron emission with faraday rotation |
in the framework of portuguese radio astronomical capacitation towards participation in the square kilometer array (ska) project, a site was selected for radio astronomical testing purposes and the development of a radio astronomical infrastructure. the site is within herdade da contenda (hc), a large national forest p... | radio astronomy demonstrator: assessment of the appropriate sites through a gis open source application |
we have used the unique low frequency sensitivity of the large phased array (lpa) radio telescope of pushchino radio astronomy observatory to collect a dataset consisting of single pulse observations of second period pulsars in the northern hemisphere. during observation sessions in 2011-2017, we collected data on 71 p... | search for giant pulses of radio pulsars at frequency 111 mhz with lpa radio telescope |
ngc 6946 is a high-star-formation-rate, face-on, spiral galaxy that has hosted 10 supernovae since 1917. not surprisingly, a large number of supernova remnants and candidates have been identified either as optical nebulae with high [s ii]:hα line ratios (147) or as compact non-thermal radio sources (35). however, there... | the supernova remnant population of ngc 6946 as observed in [fe ii] 1.644 μm with hst |
we report on the first detection of pulsed radio emission from a radio pulsar with the atacama large millimeter/submillimeter array (alma) telescope. the detection was made in the band-3 frequency range (85-101 ghz) using alma in the phased-array mode developed for vlbi observations. a software pipeline has been implem... | detection of pulses from the vela pulsar at millimeter wavelengths with phased alma |
we present radio and infrared observations indicating ongoing star formation activity inside the ∼2-5 pc circumnuclear ring at the galactic center. collectively these measurements suggest a continued disk-based mode of ongoing star formation has taken place near sgr a* over the last few million years. first, very large... | signatures of young star formation activity within two parsecs of sgr a* |
the exact mechanism for the production of fast γ-ray variability in blazars remains debated. magnetic reconnection, in which plasmoids filled with relativistic particles and magnetic fields are formed, is a viable candidate to explain the broadband electromagnetic spectrum and variability of these objects. using state-... | the observability of plasmoid-powered γ-ray flares with the fermi large area telescope |
results of timing measurements of the pulsar psr b0329+54 obtained in 1968-2012 using the big scanning antenna of the pushchino radio astronomy observatory (at 102 and 111 mhz), the dss 13 and dss 14 telescopes of the jet propulsion laboratory (2388 mhz), and the 64 m telescope of the kalyazin radio astronomy observato... | on the existence of planets around the pulsar psr b0329+54 |
fast radio bursts (frbs) are quickly becoming a subject of intense interest in time-domain astronomy. the progenitors of frbs remain unknown but a wide variety of models exist from cataclysmic to repeating scenarios. advances in frb detection using current and next-generation radio telescopes will enable the growth of ... | fast radio bursts: recent discoveries and future prospects |
for the duration of the fermi gamma-ray space telescope's mission, approximately one-third of the point sources detected have been noted as "unassociated," meaning that they seem to have no known counterpart at any other wavelength/frequency. this mysterious part of the gamma-ray sky is perhaps one of the largest unkno... | radio counterpart candidates to unassociated 4fgl-dr2 sources |
we report the first detection in space of the two doubly deuterated isotopologues of methyl acetylene. the species chd2cch and ch2dccd were identified in the dense core l483 through, respectively, nine and eight rotational lines in the 72-116 ghz range using the 30 m telescope of the institut de radioastronomie millimé... | first detection of doubly deuterated methyl acetylene (chd2cch and ch2dccd) |
we present the first mid-infrared (mir) detections of hnc and ${{\rm{h}}}^{13}\mathrm{cn}$ in the interstellar medium, and numerous resolved hcn rovibrational transitions. our observations span 12.8-22.9 μm toward the hot core orion irc2, obtained with the echelon-cross-echelle spectrograph aboard the stratospheric obs... | the first mid-infrared detection of hnc in the interstellar medium: probing the extreme environment toward the orion hot core |
we present optical, radio, and x-ray observations of a rapidly evolving transient sn2019wxt (ps19hgw), discovered during the search for an electromagnetic counterpart to the gravitational-wave (gw) trigger s191213g. although s191213g was not confirmed as a significant gw event in the off-line analysis of ligo-virgo dat... | sn2019wxt: an ultrastripped supernova candidate discovered in the electromagnetic follow-up of a gravitational wave trigger |
the event horizon telescope (eht) recently released the first horizon-scale images of the black hole in m87. combined with other astronomical data, these images constrain the mass and spin of the hole as well as the accretion rate and magnetic flux trapped on the hole. an important question for the eht is how well key ... | vlbinet: radio interferometry data classification for eht with neural networks |
the goal of the search for extraterrestrial intelligence (seti) is the detection of nonhuman technosignatures, such as technology-produced emission in radio observations. while many have speculated about the character of such technosignatures, radio seti fundamentally involves searching for signals that not only have n... | setigen: simulating radio technosignatures for the search for extraterrestrial intelligence |
song is a global ground-based network of 1m telescopes for stellar time-domain science, an international collaboration involving many countries across the world. in order to enable a favorable duty cycle, the song network plans to create a homogeneous distribution of four nodes in each of the northern and southern hemi... | optical observing conditions at delingha station |
we have used the taeduk radio astronomy observatory to observe the orion a and ophiuchus clouds in the j = 1-0 lines of 13co, c18o, hcn, hco+, and n2h+ and the j = 2-1 line of cs. the fully sampled maps with uniform noise levels are used to create moment maps. the variations of the line intensity and velocity dispersio... | times. i. a systematic observation in multiple molecular lines toward the orion a and ophiuchus clouds |
we report the performance of the 13.7-meter taeduk radio astronomy observatory (trao) radio telescope. the telescope has been equipped with a new receiver, sequoia-trao, a new backend system, fft2g, and a new vxworks operating system. the receiver system features a 16-pixel focal plane array using high-performance mmic... | performance of the trao 13.7-m telescope with new systems |
we present the results from atacama large millimeter/submillimeter array imaging in the [n ii] 205μm fine-structure line (hereafter [n ii]) and the underlying continuum of bri 1202-0725, an interacting galaxy system at z = 4.7, consisting of a quasi-stellar object (qso), a submillimeter galaxy (smg), and two lyα emitte... | alma [n ii] 205 μm imaging spectroscopy of the interacting galaxy system bri 1202-0725 at redshift 4.7 |
the millimeter-wavelength multibeam superconducting receiver (called superconducting imaging spectrometer) developed by purple mountain observatory was installed on the 13.7 m telescope at the end of 2010. to improve the observational capability of the multibeam superconducting imaging spectrometer, purple mountain obs... | spectral line on-the-fly observing system of the delingha 13.7 m telescope |
at the argentine institute of radio astronomy (iar), we carry out a pulsar-timing program in which we observe a series of pulsars from the southern hemisphere with up to daily cadence, as part of the puma project. | detection of a new glitch in the pulsar psr j1740-3015 |
the central molecular zone (cmz) of the galactic centre has to date only been fully mapped at mm wavelengths with single-dish telescopes, with resolution about 30 arcsec (1.2 pc). using combined array for research in millimeter-wave astronomy (carma), we mapped the innermost 0.25 deg2 of the cmz over the region between... | the carma 3 mm survey of the inner 0.7° × 0.4° of the central molecular zone |
we report rest frequencies for rotational transitions of the deuterated ammonium isotopologues nh3d+, nh2d2 +, and nhd3 +, measured in a cryogenic ion trap machine. for the symmetric tops nh3d+ and nhd3 +, one and three transitions are detected, respectively, and five transitions are detected for the asymmetric top nh2... | accurate rotational rest frequencies for ammonium ion isotopologues |
a new era in radio astronomy will begin with the upcoming large-scale surveys planned at the australian square kilometre array pathfinder (askap). askap started its early science programme in october 2017 and several target fields were observed during the array commissioning phase. the suc(corpio) field was the first o... | cuc(aesar) source finder: recent developments and testing |
high-resolution gas phase spectroscopy techniques in the microwave, millimeter-wave and terahertz spectral ranges can be used to study complex organic molecules desorbed from interstellar ice analogues surface with a high sensitivity. high-resolution gas phase spectroscopy gives unambiguous information about the molecu... | high-resolution gas phase spectroscopy of molecules desorbed from an ice surface: a proof-of-principle study |
we present program objectives and specifications for the first generation ultra-fast astronomy (ufa) observatory which will explore a new astrophysical phase space by characterizing the variability of the optical (320 nm - 650 nm) sky in the millisecond to nanosecond timescales. one of the first objectives of the ufa o... | program objectives and specifications for the ultra-fast astronomy observatory |
in this habilitationsschrift (habilitation thesis) i present my research carried out over the last four years at the argelander institute for astronomy (aifa) and the max planck institute for radio astronomy (mpifr). the thesis summarizes my main findings and has been written to fulfill the requirements for the habilit... | millisecond pulsars in close binaries |
we developed a dual-linear-polarization hemt (high electron mobility transistor) amplifier receiver system of the 45-ghz band (hereafter z45), and installed it in the nobeyama 45-m radio telescope. the receiver system is designed to conduct polarization observations by taking the cross-correlation of two linearly polar... | z45: a new 45-ghz band dual-polarization hemt receiver for the nro 45-m radio telescope |
we study the long-term (≈ 30 years) radio variability of 43 radio-bright active galactic nuclei (agns) by exploiting the database of the university of michigan radio astronomy observatory monitoring program. we model the periodograms (temporal power spectra) of the observed light curves as simple power-law noise (red n... | the long-term centimeter variability of active galactic nuclei: a new relation between variability timescale and accretion rate |
high-energy astrophysical neutrinos have been observed by several telescopes in the last decade, but their sources still remained unknown. we address the problem of locating astrophysical neutrinos' sources in a statistical manner. we show that blazars positionally associated with icecube neutrino detections have stron... | radio astronomy locates the neutrino origin in bright blazars |
general relativity is one of the pillars of modern physics. for decades, the theory has been mainly tested in the weak-field regime with experiments in the solar system and radio observations of binary pulsars. until 2015, the strong-field regime was almost completely unexplored. thanks to new observational facilities,... | x-ray tests of general relativity with black holes |
accurate antenna beam models are critical for radio observations aiming to isolate the redshifted 21 cm spectral line emission from the dark ages and the epoch of reionization (eor) and unlock the scientific potential of 21 cm cosmology. past work has focused on characterizing mean antenna beam models using either sate... | beam-forming errors in murchison widefield array phased array antennas and their effects on epoch of reionization science |
modern scientific instruments produce vast amounts of data, which can overwhelm the processing ability of computer systems. lossy compression of data is an intriguing solution, but comes with its own drawbacks, such as potential signal loss, and the need for careful optimization of the compression ratio. in this work, ... | compressive sensing using iterative hard thresholding with low precision data representation: theory and applications |
the reaction between the amidogen, nh, radical and the ethyl, c2h5, radical has been investigated by performing electronic structure calculations of the underlying doublet potential energy surface. rate coefficients and product branching ratios have also been estimated by combining capture and rrkm calculations. accord... | a theoretical investigation of the reaction between the amidogen, nh, and the ethyl, c2h5, radicals: a possible gas-phase formation route of interstellar and planetary ethanimine |
machine learning techniques that perform morphological classification of astronomical sources often suffer from a scarcity of labelled training data. here, we focus on the case of supervised deep learning models for the morphological classification of radio galaxies, which is particularly topical for the forthcoming la... | morphological classification of radio galaxies with wasserstein generative adversarial network-supported augmentation |
some short gamma-ray bursts (sgrbs) are thought to be caused by the mergers of binary neutron stars which may sometimes produce massive neutron star remnants capable of producing extragalactic fast radio bursts (frbs). we conducted a deep search for frbs from the sites of six low-redshift sgrbs. we collected high time-... | a deep targeted search for fast radio bursts from the sites of low-redshift short gamma-ray bursts |
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