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we analyze the cooling and feedback properties of 48 galaxy clusters at redshifts 0.4 < z < 1.3 selected from the south pole telescope (spt) catalogs to evolve like the progenitors of massive and well-studied systems at z ~ 0. we estimate the radio power at the brightest cluster galaxy (bcg) location of each clus... | redshift evolution of the feedback-cooling equilibrium in the core of 48 spt galaxy clusters: a joint chandra-spt-atca analysis |
fast radio bursts (frbs) are bright radio transients of microsecond to millisecond duration and unknown extragalactic origin. central to the mystery of frbs are their extremely high characteristic energies, which surpass the typical energies of other radio transients of similar duration, like galactic pulsar and magnet... | flux calibration of chime/frb intensity data |
the dragonfly galaxy (mrc 0152-209), the most infrared-luminous radio galaxy at redshift z ~ 2, is a merger system containing a powerful radio source and large displacements of gas. we present kiloparsec-resolution data from the atacama large millimeter/submillimeter array and the very large array of carbon monoxide (6... | the dragonfly galaxy. iii. jet brightening of a high-redshift radio source caught in a violent merger of disk galaxies |
we report on the measurement of the thermal sunyaev-zel'dovich (tsz) effect in the circumgalactic medium (cgm) of 641,923 galaxies with m ⋆ = 109.8-11.3 m ⊙ at z < 0.5, pushing the exploration of the tsz effect to lower-mass galaxies compared to those in previous studies. we cross-correlate the galaxy catalog of the... | detection of thermal sunyaev-zel'dovich effect in the circumgalactic medium of low-mass galaxies-a surprising pattern in self-similarity and baryon sufficiency |
we present the early science results from a blind search of the extragalactic h i 21 cm absorption lines at z ≤ 0.09 with the drift-scan observation of the five-hundred-meter aperture spherical radio telescope (fast). we carried out the search using the data collected over 643.8 h by the ongoing commensal radio astrono... | detections of 21 cm absorption with a blind fast survey at z ≤ 0.09 |
the emerging field of radio based neutrino astronomy holds promise in answering long lasting questions about our universe such as identifying the sources of ultra-high energy (uhe) cosmic rays. this requires a multi-messenger effort in astronomy which is a relatively new collaboration between the various particles/wave... | quantifying the neutrino energy and pointing resolution of the arianna detector |
the lunar surface allows a unique way forward in cosmology, to go beyond current limits. the far side provides an unexcelled radio-quiet environment for probing the dark ages via 21 cm interferometry to seek elusive clues on the nature of the infinitesimal fluctuations that seeded galaxy formation. far-infrared telesco... | the limits of cosmology: role of the moon |
this document describes some of the fundamental astrophysical problems that require observing capabilities at millimeter- and centimeter wavelengths well beyond those of existing, or already planned, telescopes. the results summarized in this report follow a solicitation from the national radio astronomy observatory to... | key science goals for the next generation very large array (ngvla): report from the ngvla science advisory council |
the "square kilometre array" (ska) is a large international radio telescope project characterised, as suggested by its name, by a total collecting area of approximately one square kilometre, and consisting of several interferometric arrays to observe at metric and centimetric wavelengths. the deployment of the ska will... | french ska white book - the french community towards the square kilometre array |
fast radio bursts (frbs) are millisecond-duration intense radio flares occurring at cosmological distances. many models have been proposed to explain these topical astronomical events, but none has so far been confirmed. here we show that a novel way involving enhanced giant radio pulses from a rapidly spun-up neutron ... | fast radio bursts from neutron stars plunging into black holes |
we present detections of 21 cm emission from neutral hydrogen (h i) in the circumgalactic medium (cgm) of the local edge-on galaxies ngc 891 and ngc 4565 using the robert c. byrd green bank telescope (gbt). with our 5σ sensitivity of $8.2\times {10}^{16}$ cm-2 calculated over a 20 km s-1 channel, we achieve $\gt 5\sigm... | detection of the diffuse h i emission in the circumgalactic medium of ngc 891 and ngc 4565 |
we investigate the kinematics of neutral gas in the small magellanic cloud (smc) and test the hypothesis that it is rotating in a disk. to trace the 3d motions of the neutral gas distribution, we identify a sample of young, massive stars embedded within it. these are stars with radial velocity measurements from spectro... | the 3d kinematics of gas in the small magellanic cloud |
we present a systematic analysis of the mid-infrared (mir) properties of the youngest radio galaxies, based on low-resolution data provided by the wide-field infrared survey explorer and iras satellites. we restrict our analysis to sources with available x-ray data that constitute the earliest phase of radio galaxy evo... | mid-infrared diagnostics of the circumnuclear environments of the youngest radio galaxies |
we present an analysis of the internal velocity structures of the newly identified sub-0.1 pc coherent structures, droplets, in l1688 and b18. by fitting 2d linear velocity fields to the observed maps of velocity centroids, we determine the magnitudes of linear velocity gradients and examine the potential rotational mo... | droplets. ii. internal velocity structures and potential rotational motions in pressure-dominated coherent structures |
computational workflows are widely used in data analysis, enabling innovation and decision-making. in many domains (bioinformatics, image analysis, & radio astronomy) the analysis components are numerous and written in multiple different computer languages by third parties. however, many competing workflow systems ... | methods included: standardizing computational reuse and portability with the common workflow language |
we present a new algorithm for stacking radio interferometric data in the uv-domain. the performance of uv-stacking is compared to the stacking of fully imaged data using simulated atacama large millimeter/submillimeter array and the karl g. jansky very large array (vla) deep extragalactic surveys. we find that image- ... | stacking of large interferometric data sets in the image- and uv-domain - a comparative study |
the non-uniform distribution of gas and protostars in molecular clouds is caused by combinations of various physical processes that are difficult to separate. we explore this non-uniform distribution in the m17 molecular cloud complex that hosts massive star formation activity using the 12co (j = 1-0) and 13co (j = 1-0... | large-scale molecular gas distribution in the m17 cloud complex: dense gas conditions of massive star formation? |
this article is a second analysis step from the descriptive arxiv:2001.10952 preprint. this work is aimed to arise awareness to the scientific astronomical community about the negative impact of satellites' mega-constellations and put in place an approximated estimations about loss of scientific contents expected for g... | concerns about ground based astronomical observations: quantifying satellites' constellations damages |
we present a detailed analysis of the disk and circumstellar environment of the forming o-type star afgl 4176 mm1, placing results from the atacama large millimeter/submillimeter array (alma) into context with multiwavelength data. with alma, we detect seventeen 1.2 mm continuum sources within 5″ (21,000 au) of afgl 41... | a detailed view of the circumstellar environment and disk of the forming o-star afgl 4176 |
reconstruction of the sky brightness measured by radio interferometers is typically achieved through gridding techniques, or histograms in spatial fourier space. for epoch of reionization (eor) 21 cm power spectrum measurements, extreme levels of gridding resolution are required to reduce spectral contamination, as exp... | the role of the instrumental response in 21 cm epoch of reionization power spectrum gridding analyses |
global 21-cm experiments require exquisitely precise calibration of the measurement systems in order to separate the weak 21-cm signal from galactic and extragalactic foregrounds as well as instrumental systematics. hitherto, experiments aiming to make this measurement have concentrated on measuring this signal using t... | system design and calibration of sitara—a global 21 cm short spacing interferometer prototype |
ultra-high-energy neutrinos serve as messengers of some of the highest energy astrophysical environments. given that neutrinos are neutral and only interact via weak interactions, neutrinos can emerge from sources, traverse astronomical distances, and point back to their origins. their weak interactions require large t... | neutrino propagation in the earth and emerging charged leptons with nupyprop |
the sardinia radio telescope is a quasi-gregorian system with a shaped 64 m diameter primary reflector and a 7.9 m diameter secondary reflector. it was designed to operate with high efficiency across the 0.3–116 ghz frequency range. the telescope is equipped with a cryogenic coaxial dual-frequency l-p band receiver, wh... | upgrading of the l-p band cryogenic receiver of the sardinia radio telescope: a feasibility study |
isolated mgsio3 and mg2sio4 molecules are shown here to exhibit bright infrared (ir) features that fall close to unattributed astronomical lines observed toward objects known to possess crystalline enstatite and forsterite, minerals of the same respective empirical formulae. these molecules are therefore tantalizing ca... | enstatite (mgsio3) and forsterite (mg2sio4) monomers and dimers: highly detectable infrared and radioastronomical molecular building blocks |
radio telescopes are used by astronomers to observe the naturally occurring radio waves generated by planets, interstellar molecular clouds, galaxies, and other cosmic objects. these telescopes are equipped with radio receivers that cover a portion of the radio frequency (rf) and millimetre-wave spectra. the sardinia r... | adaptation of an iram w-band sis receiver to the inaf sardinia radio telescope: a feasibility study and preliminary tests |
we discuss the first results from our mid-infrared (mir) imaging survey of milky way giant h ii (gh ii) regions with our detailed analysis of w51a, which is one of the largest gh ii regions in our galaxy. we used the forcast instrument on the stratospheric observatory for infrared astronomy (sofia) to obtain 20 and 37 ... | surveying the giant h ii regions of the milky way with sofia. i. w51a |
the possible association with the high-energy neutrino event icecube-170922a has sparked interest in the blazar txs 0506+056. we present 72 instantaneous 1-22 ghz spectra measured over the past 20 years with the ratan-600 telescope and compare them with the results of observations of 700 variable active galactic nuclei... | ratan-600 and radioastron reveal the neutrino-associated blazar txs 0506+056 as a typical variable agn |
the study of binary pulsars enables tests of general relativity. orbital motion in binary systems causes the apparent pulsar spin frequency to drift, reducing the sensitivity of periodicity searches. acceleration searches are methods that account for the effect of orbital acceleration. existing methods are currently co... | a gpu implementation of the correlation technique for real-time fourier domain pulsar acceleration searches |
the low frequency array (lofar) radio telescope is an international aperture synthesis radio telescope used to study the universe at low frequencies. one of the goals of the lofar telescope is to conduct deep wide-field surveys. here we will discuss a framework for the processing of the lofar two meter sky survey (lots... | an automated scalable framework for distributing radio astronomy processing across clusters and clouds |
pyse is a python software package for finding and measuring sources in radio telescope images. the software was designed to detect sources in the lofar telescope images, but can be used with images from other radio telescopes as well. we introduce the lofar telescope, the context within which pyse was developed, the de... | pyse: software for extracting sources from radio images |
we probed the magnetic fields in high-redshift galaxies using excess extragalactic contribution to residual rotation measure (rrm) for quasar sightlines with intervening mg ii absorbers. based on a large sample of 1132 quasars, we have computed rrm distributions broadening using median absolute deviation from the mean ... | role of intervening mg ii absorbers on the rotation measure and fractional polarization of the background quasars |
we present a detailed analysis of high-resolution c18o (2-1), so (88-77), co (3-2), and dco+ (3-2) data obtained by the atacama large millimeter/submillimeter array toward a class 0 keplerian circumbinary disk around vla 1623a, which represents one of the most complete analyses toward a class 0 source. from the dendrog... | determining the physical conditions of an extremely young class 0 circumbinary disk around vla 1623a |
we report the results from a new, highly sensitive (δt mb ∼ 3 mk) survey for thermal oh emission at 1665 and 1667 mhz over a dense, 9 × 9 pixel grid covering a 1° × 1° patch of sky in the direction of l = 105.°00, b = +2.°50 toward the perseus spiral arm of our galaxy. we compare our green bank telescope 1667 mhz oh re... | the structure of dark molecular gas in the galaxy. ii. physical state of “co-dark” gas in the perseus arm |
in this work, we aim to characterize high-mass clumps with infall motions. we selected 327 clumps from the millimetre astronomy legacy team 90-ghz survey, and identified 100 infall candidates. combined with the results of he et al., we obtained a sample of 732 high-mass clumps, including 231 massive infall candidates a... | properties of massive star-forming clumps with infall motions |
the planck mission detected thousands of extragalactic radio sources at frequencies from 28 to 857 ghz. planck's calibration is absolute (in the sense that it is based on the satellite’s annual motion around the sun and the temperature of the cosmic microwave background), and its beams are well characterized at sub-per... | absolute calibration of the radio astronomy flux density scale at 22 to 43 ghz using planck |
the very existence of more than a dozen of high-redshift (z ≳ 4) blazars indicates that a much larger population of misaligned powerful jetted active galactic nucleus (agn) was already in place when the universe was ≲1.5 gyr old. such parent population proved to be very elusive, and escaped direct detection in radio su... | cmb quenching of high-redshift radio-loud agns |
we present a multi-frequency far-field beam map for the 5m dish telescope at the bleien observatory measured using a commercially available drone. we describe the hexacopter drone used in this experiment, the design of the flight pattern, and the data analysis scheme. this is the first application of this calibration m... | beam calibration of radio telescopes with drones |
context. images of spatially resolved astrophysical objects contain a wealth of morphological and dynamical information, and effectively extracting this information is of paramount importance for understanding the physics and evolution of these objects. the algorithms and methods currently employed for this purpose (su... | wavelet-based decomposition and analysis of structural patterns in astronomical images |
an fpga-based digital-receiver has been developed for a low-frequency imaging radio interferometer, the murchison widefield array (mwa). the mwa, located at the murchison radio-astronomy observatory (mro) in western australia, consists of 128 dual-polarized aperture-array elements (tiles) operating between 80 and 300 m... | a digital-receiver for the murchisonwidefield array |
observations from past missions such as rxte and beppo-sax suggested the presence of inverse compton (ic) scattering at hard x-ray energies within the intracluster medium of some massive galaxy clusters. in subsequent years, observations by, e.g., suzaku, and now nustar, have not been able to confirm these detections. ... | nustar observations of abell 665 and 2146: constraints on nonthermal emission |
astronomers often have to deal with randomness. for example, stars and radio telescopes are sources of randomness. on the other hand, randomly distributed stars in some astronomical images can make harder the task of an algorithm that aims the automatic identification of important structures in the image. therefore, a ... | disentropy in astronomy |
the haystack telescope is an antenna with a diameter of 37 m and an elevation-dependent surface accuracy of ≤100μm that is capable of millimeter-wave observations. the radome-enclosed instrument serves as a radar sensor for space situational awareness, with about one-third of the time available for research by mit hays... | the haystack telescope as an astronomical instrument |
newly available high-resolution imaging of solar radio emission at many closely spaced frequencies and times provides new physical insight into the processes, structure, and dynamics of the solar atmosphere. the observational advances have spurred renewed interest in topics dating from the early days of solar radio ast... | new insights from imaging spectroscopy of solar radio emission |
psr j2021+4026 is a radio-quiet gamma-ray pulsar and the first pulsar that shows state change of the gamma-ray emission and spindown rate. the state change of psr j2021+4026 was first observed at 2011 october, at which the pulsar changes the state from high gamma-ray flux/low spindown rate state to low gamma-ray flux/h... | repeated state change of variable gamma-ray pulsar psr j2021+4026 |
with its immensity and numerous mysteries waiting to be solved, the cosmos has always captivated humankind. a ground-breaking field that has given us a profound understanding of the mysteries of the cosmos is radio astronomy. this paper presents a comprehensive overview of radio astronomy, exploring its techniques, dis... | unveiling the mysteries of the cosmos: an overview of radio astronomy and its profound insights |
new, massively redundant low-frequency arrays allow for a novel investigation of closure relations in interferometry. we employ commissioning data from the hydrogen epoch of reionization array to investigate closure quantities in this densely packed grid array of 14-m antennas operating at 100 to 200 mhz. we investigat... | h i 21-cm cosmology and the bispectrum: closure diagnostics in massively redundant interferometric arrays |
nowadays, fast radio bursts (frbs) have been a promising probe for astronomy and cosmology. however, it is not easy to identify the redshifts of frbs to date. thus, no sufficient actual frbs with identified redshifts can be used to study cosmology currently. in the past years, one has to use the simulated frbs with "kn... | effect of redshift distributions of fast radio bursts on cosmological constraints |
recently, coherent radio emission has been discovered from a number of hot magnetic stars, via the process of electron cyclotron maser emission (ecme). this emission, observed in the form of highly circularly polarized pulses, has interesting properties that contain information about the host star. one of the important... | a 3d framework to explore the propagation effects in stars exhibiting electron cyclotron maser emission |
we report the time variability of the late-time radio emission in a type i superluminous supernova (slsn), ptf10hgi, at z = 0.0987. the karl g. jansky very large array 3 ghz observations at 8.6 and 10 yr after the explosion both detected radio emission with a ∼40% decrease in flux density in the second epoch. this is t... | variability of late-time radio emission in the superluminous supernova ptf10hgi |
in this work we introduce group-equivariant self-attention models to address the problem of explainable radio galaxy classification in astronomy. we evaluate various orders of both cyclic and dihedral equivariance, and show that including equivariance as a prior both reduces the number of epochs required to fit the dat... | e(2) equivariant self-attention for radio astronomy |
recently vernstrom et al. (2021, mnras) claimed the first definitive detection of the synchrotron cosmic web, obtained by `stacking' hundreds of thousands of pairs of close-proximity clusters in low-frequency radio observations and looking for a residual excess signal spanning the intracluster bridge. a reproduction st... | stacking the synchrotron cosmic web with figaro |
the recent discovery of a 4 × 107 m ⊙ black hole (bh) in uhz1 at z = 10.3, just 450 myr after the big bang, suggests that the seeds of the first quasars may have been direct-collapse bhs from the collapse of supermassive primordial stars at z ~ 20. this object was identified in james webb space telescope nircam and cha... | radio emission from a z = 10.1 black hole in uhz1 |
extended very-high-energy (vhe; 0.1-100 tev) γ-ray emission has been observed around several middle-aged pulsars and referred to as "tev halos." their formation mechanism remains under debate. it is also unknown whether they are ubiquitous or related to a certain subgroup of pulsars. with 2321 days of observation, the ... | hawc detection of a tev halo candidate surrounding a radio-quiet pulsar |
the far-infrared radio correlation (firc) is one of the strongest correlations in astronomy, yet a model that explains this comprehensively does not exist. the new lofar all sky survey (lotss) deep field, elais-n1, allows exploration of this relation in previously unexplored regions of parameter space of radio frequenc... | the lofar two-metre sky survey deep fields. the mass dependence of the far-infrared radio correlation at 150 mhz using deblended herschel fluxes |
we report the independent discovery of psr j0026-1955 with the murchison widefield array (mwa) in the ongoing southern-sky mwa rapid two-metre pulsar survey. j0026-1955 has a period of ~1.306 s, a dispersion measure of ~20.869 pc cm-3, and a nulling fraction of ~77%. this pulsar highlights the advantages of the survey'... | independent discovery of a nulling pulsar with unusual subpulse drifting properties with the murchison widefield array |
to facilitate the study of solar flares and active regions, we have created a modeling framework, the freely distributed gx simulator idl package, that combines 3d magnetic and plasma structures with thermal and nonthermal models of the chromosphere, transition region, and corona. its object-based modular architecture,... | data-constrained solar modeling with gx simulator |
the cryogenic sapphire oscillator (cso) is a highly specialized machine, which delivers a reference signal exhibiting the lowest frequency fluctuations. for the best units, the allan deviation (adev) is <1e-15 for integration time between 1 and 10,000 s, with a drift <1e-14 in one day.the oscillator is based on a... | reliability and reproducibility of the cryogenic sapphire oscillator technology |
we have observed the mass-losing carbon star v hya that is apparently transitioning from an asymptotic giant branch star to a bipolar planetary nebula, at an unprecedented angular resolution of ~0.″4-0.″6 with the atacama large millimeter/submillimeter array. our 13co and 12co (j = 3-2 and j = 2-1) images have led to t... | the rapidly evolving asymptotic giant branch star, v hya: alma finds a multiring circus with high-velocity outflows |
novel techniques are indispensable to process the flood of data from the new generation of radio telescopes. in particular, the classification of astronomical sources in images is challenging. morphological classification of radio galaxies could be automated with deep learning models that require large sets of labelled... | radio galaxy classification with wgan-supported augmentation |
radio holographic measurements using the meerkat telescope are presented for each of its supported observing bands, namely uhf (544-1087 mhz), l (856-1711 mhz), and s (1750-3499 mhz). because the uhf-band receiver design is a scaled version of that of the l band, the electromagnetic performance in these two bands are e... | meerkat holography measurements in the uhf, l, and s bands |
some afterglow light curves of gamma-ray bursts (grbs) exhibit very complex temporal and spectral features, such as a sudden intensity jump about one hour after the prompt emission in the optical band. we assume that this feature is due to the late collision of two relativistic shells and investigate the corresponding ... | multi-messenger detection prospects of gamma-ray burst afterglows with optical jumps |
the einstein’s weak equivalence principle (wep) is one of the foundational assumptions of general relativity and some other gravity theories. in the theory of parametrized post-newtonian (ppn), the difference between the ppn parameters γ of different particles or the same type of particle with different energies, δγ, r... | a new method to test the einstein’s weak equivalence principle |
modern radio telescopes combine thousands of receivers, long-distance networks, large-scale compute hardware, and intricate software. due to this complexity, failures occur relatively frequently. in this work, we propose novel use of unsupervised deep learning to diagnose system health for modern radio telescopes. the ... | deep learning assisted data inspection for radio astronomy |
context. glycolamide is a glycine isomer and also one of the simplest derivatives of acetamide (e.g., one hydrogen atom is replaced with a hydroxyl group), which is a known interstellar molecule.aims: in this context, the aim of our work is to provide direct experimental frequencies of the ground vibrational state of g... | interstellar glycolamide: a comprehensive rotational study and an astronomical search in sgr b2(n) |
in this paper we present the updated empirical radio surface-brightness-to-diameter (σ-d) relation for galactic supernova remnants (snrs) calibrated using 110 snrs with reliable distances. we apply orthogonal fitting procedure and kernel density smoothing in the σ-d plane and compare the results with the latest theoret... | updated radio σ-d relation for galactic supernova remnants - ii |
electron acceleration in the solar corona is often associated with flares and the eruption of twisted magnetic structures known as flux ropes. however, the locations and mechanisms of such particle acceleration during the flare and eruption are still subject to much investigation. observing the exact sites of particle ... | radio diagnostics of electron acceleration sites during the eruption of a flux rope in the solar corona |
pulsars are highly magnetized and rapidly rotating neutron stars. as they spin, the lighthouse-like beam of radio emission from their magnetic poles sweeps across the earth with a regularity approaching that of the most precise clocks known. this precision combined with the extreme environments in which they are found,... | the prospects of pulsar timing with new-generation radio telescopes and the square kilometre array |
context. the volume of radio-astronomical data is a considerable burden in the processing and storing of radio observations that have high time and frequency resolutions and large bandwidths. for future telescopes such as the square kilometre array (ska), the data volume will be even larger.aims: lossy compression of i... | compression of interferometric radio-astronomical data |
we report results of investigation of amplitude calibration for very long baseline interferometry (vlbi) observations with korean vlbi network (kvn). amplitude correction factors are estimated based on comparison of kvn observations at 22~ghz correlated by daejeon hardware correlator and difx software correlator in kor... | amplitude correction factors of korean vlbi network observations |
a "large-n" correlator that makes use of field programmable gate arrays and graphics processing units has been deployed as the digital signal processing system for the long wavelength array station at owens valley radio observatory (lwa-ov), to enable the large aperture experiment to detect the dark ages (leda). the sy... | digital signal processing using stream high performance computing: a 512-input broadband correlator for radio astronomy |
we present a novel natural language processing (nlp) approach to deriving plain english descriptors for science cases otherwise restricted by obfuscating technical terminology. we address the limitations of common radio galaxy morphology classifications by applying this approach. we experimentally derive a set of seman... | radio galaxy zoo emu: towards a semantic radio galaxy morphology taxonomy |
the spatial distribution of cosmic ray (cr) particles in the interstellar medium (ism) is of major importance in radio astronomy, where its knowledge is essential for the interpretation of observations, and in theoretical astrophysics, where crs contribute to the structure and dynamics of the ism. local inhomogeneities... | cosmic rays and random magnetic traps |
we present a method to estimate the source properties of fast radio bursts (frbs) from observations by assuming a fixed dispersion measure contribution from a milky way-like host galaxy, pulse temporal broadening models for turbulent plasma, and a flat frb energy spectrum. then we perform monte carlo simulations to con... | population modeling of fast radio bursts from source properties |
agn are quite unique astronomical sources emitting over more than twenty orders of magnitude in frequency, with different electromagnetic bands providing windows on different sub-structures and their physics. they come in a large number of flavors only partially related to intrinsic differences. i highlight here the ty... | active galactic nuclei at all wavelengths and from all angles |
the observed features of the radio source indicate that the waves of solar radio bursts are convoluted with complex propagation effects. in this work, we perform ray-tracing simulations on radio wave transport in the corona and interplanetary region with anisotropic electron density fluctuations. for the first time, th... | parametric simulation studies on the wave propagation of solar radio emission: the source size, duration, and position |
the central challenge in 21 cm cosmology is isolating the cosmological signal from bright foregrounds. many separation techniques rely on the accurate knowledge of the sky and the instrumental response, including the antenna primary beam. for drift-scan telescopes, such as the hydrogen epoch of reionization array (hera... | measuring hera's primary beam in situ: methodology and first results |
this paper presents a framework to compute the receiver noise temperature (trcv) of two low-frequency radio telescopes, the murchison widefield array (mwa) and the engineering development array (eda). the mwa was selected because it is the only operational low-frequency square kilometre array (ska) precursor at the mur... | noise temperature of phased array radio telescope: the murchison widefield array and the engineering development array |
two components of jets associated with the afterglow of the gamma-ray burst (grb) 160623a were observed with multifrequency observations including long-term monitoring in a submillimeter range (230 ghz) using the submillimeter array. the observed light curves with temporal breaks suggest on the basis of the standard fo... | two-component jets of grb 160623a as shocked jet cocoon afterglow |
we investigate the resolved kinematics of the molecular gas, as traced by the atacama large millimeter/submillimeter array in co (2-1), of 25 cluster member galaxies across three different clusters at a redshift of z ~ 1.6. this is the first large-scale analysis of the molecular gas kinematics of cluster galaxies at th... | a large-scale kinematic study of molecular gas in high-z cluster galaxies: evidence for high levels of kinematic asymmetry |
a tidal disruption event (tde) occurs when a supermassive black hole rips apart a passing star. part of the stellar material falls toward the black hole, forming an accretion disk that in some cases launches a relativistic jet. we performed optical polarimetry observations of a tde, at 2020mot. we find a peak linear po... | optical polarization from colliding stellar stream shocks in a tidal disruption event |
active galactic nuclei (agns) in the high-redshift universe are thought to reside in overdense environments. however, recent works provide controversial results, partly due to the use of different techniques and possible suppression of nearby galaxy formation by agn feedback. we conducted deep and wide-field imaging ob... | active galactic nucleus environments and feedback to neighboring galaxies at z ∼ 5 probed by lyα emitters |
one of the advantages of arrays with aperiodic distributed elements is their ability to mitigate the detrimental mutual coupling effects on the radiation pattern. however, we show that the mutual coupling inside a random array can still generate undesired structures in the frequency response although the single antenna... | impact of mutual coupling between skala4.1 antennas to the spectral smoothness response |
the stellar cluster environment is expected to play a central role in the evolution of circumstellar disks. we use thermochemical modeling to constrain the dust and gas masses, disk sizes, uv and x-ray radiation fields, viewing geometries, and central stellar masses of 20 class ii disks in the orion nebula cluster (onc... | chemical modeling of orion nebula cluster disks: evidence for massive, compact gas disks with interstellar gas-to-dust ratios |
as a part of in-house instrument developmental activity at aries, the 4kx4k ccd imager is designed and developed as a first-light instrument for the axial port of the 3.6-m devasthal optical telescope (dot). the f/9 beam of the telescope having a plate-scale of 6.4"/mm is utilized to conduct deeper photom-etry within t... | first-light instrument for the 3.6-m devasthal optical telescope: 4kx4k ccd imager |
we present the results of the first transient survey from the owens valley radio observatory long wavelength array (ovro-lwa) using 31 hr of data, in which we place the most constraining limits on the instantaneous transient surface density at timescales of 13 s to a few minutes and at frequencies below 100 mhz. the ov... | new limits on the low-frequency radio transient sky using 31 hr of all-sky data with the ovro-lwa |
caracal (containerized automated radio astronomy calibration, formerly meerkathi) reduces radio-interferometric data. developed originally as an end-to-end continuum- and line imaging pipeline for meerkat, it can also be used with other radio telescopes. caracal reduces large data sets and produces high-dynamic-range c... | caracal: containerized automated radio astronomy calibration pipeline |
the astrosat satellite is designed to make multi-waveband observations of astronomical sources and the cadmium zinc telluride imager (czti) instrument of astrosat covers the hard x-ray band. czti has a large area position sensitive hard x-ray detector equipped with a coded aperture mask, thus enabling simultaneous back... | cadmium-zinc-telluride imager on-board astrosat: a multi-faceted hard x-ray instrument |
an analysis of data from monitoring of individual pulses of the second-period pulsar psr b1237+25 (j1239+2453) carried out on the large phased array (lpa) of the pushchino radio astronomy observatory at 111 mhz during 2012-2015 is presented. the aim of this observing program is a search for anomalously strong and giant... | observations of giant pulses from b1237+25 (j1239+2453) at 111 mhz. detection and classification |
results of 111-mhz monitoring observations carried out on the big scanning antenna of the pushchino radio astronomy observatory during september 1-28, 2015 are presented. fifty-four pulsating sources were detected at declinations -9° < δ < 42°. forty-seven of these are known pulsars, five are new sources, and two... | detection of five new rrats at 111 mhz |
deformations of the reflectors of radio telescopes used in geodetic and astrometric vlbi observations belong to the class of systematic error sources which affect the estimated position of the telescope and which necessitates correction at the observation level. the determination of the gravitationally induced deformat... | a vlbi delay model for gravitational deformations of the onsala 20 m radio telescope and the impact on its global coordinates |
astronomical objects frequently exhibit structure over a wide range of scales whereas many telescopes, especially interferometer arrays, only sample a limited range of spatial scales. to properly image these objects, images from a set of instruments covering the range of scales may be needed. these images then must be ... | fourier plane image combination by feathering |
the wide adoption of low-frequency radio interferometers as a tool for deeper and higher resolution astronomical observations has revolutionized radio astronomy. despite their construction from static, relatively simple dipoles, the sheer number of distinct elements introduces new, complicated instrumental effects. the... | dual polarization measurements of mwa beampatterns at 137 mhz |
we observed with the very long baseline array (vlba) at 2.3 and 8.6 ghz a complete flux-density-limited sample of 482 radio sources with decl. > +75° brighter than 200 mjy at 1.4 ghz drawn from the nvss catalog. a total of 34% of the sources show parsec-scale emission above the flux density detection limit of 30 mjy... | parsec-scale properties of steep- and flat-spectrum extragalactic radio sources from a vlba survey of a complete north polar cap sample |
we present a procedure for efficiently compressing astronomical radio data for high performance applications. integrated, post-correlation data are first passed through a nearly lossless rounding step which compares the precision of the data to a generalized and calibration-independent form of the radiometer equation. ... | a compression scheme for radio data in high performance computing |
agrowing avenue for determining the prevalence of life beyond earth is to search for "technosignatures" from extraterrestrial intelligences/agents. technosignatures require significant energy to be visible across interstellar space and thus intentional signals might be concentrated in frequency, in time, or in space, t... | a green bank telescope search for narrowband technosignatures between 1.1 and 1.9 ghz during 12 kepler planetary transits |
this paper introduces the first results of observations with the ultra-long-wavelength (ulw) —- low frequency interferometer and spectrometer (lfis) on board the selenocentric satellite longjiang-2. we present a brief description of the satellite and focus on the lfis payload. the in-orbit commissioning confirmed a rel... | ultra-low-frequency radio astronomy observations from a seleno-centric orbit |
this is the final report submitted to nasa for a probe-class concept study of the "farside array for radio science investigations of the dark ages and exoplanets" (farside), a low radio frequency interferometric array on the farside of the moon. the design study focused on the instrument, a deployment rover, the lander... | nasa probe study report: farside array for radio science investigations of the dark ages and exoplanets (farside) |
context. the galaxy population in the contemporary universe is characterised by a clear bimodality, blue galaxies with significant ongoing star formation and red galaxies with only a little. the migration between the blue and the red cloud of galaxies is an issue of active research. post starburst (psb) galaxies are th... | a large sample of kohonen selected e+a (post-starburst) galaxies from the sloan digital sky survey |
machine learning has been successfully applied in various field but whether it is a viable tool for determining the distance to molecular clouds in the galaxy is an open question. in the galaxy, the kinematic distance is commonly employed to represent the distance to a molecular cloud. however, for the inner galaxy, tw... | distance determination of molecular clouds in the first quadrant of the galactic plane using deep learning: i. method and results |
new and unique opportunities now exist to look for technosignatures (ts) beyond traditional seti radio searches, motivated by tremendous advances in exoplanet science and observing capabilities in recent years. space agencies, both public and private, may be particularly interested in learning about the community's vie... | concepts for future missions to search for technosignatures |
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