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fast radio bursts (frbs) are bright millisecond-duration radio transients that appear about 1000 times per day, all-sky, for a fluence threshold 5 jy ms at 600 mhz. the frb radio-emission physics and the compact objects involved in these events are subjects of intense and active debate. to better constrain source model... | burstt: bustling universe radio survey telescope in taiwan |
the 21cm line refers to a forbidden transition in neutral hydrogen associated with alignment of spins of the proton and electron. it is a very low energy transition that is emitted whenever there is neutral hydrogen in the universe. since baryons are mostly (~75%) hydrogen, one can in principle detect this emission thr... | snowmass2021 cosmic frontier white paper: 21cm radiation as a probe of physics across cosmic ages |
we search for gravitational-wave (gw) transients associated with fast radio bursts (frbs) detected by the canadian hydrogen intensity mapping experiment fast radio burst project, during the first part of the third observing run of advanced ligo and advanced virgo (2019 april 1 15:00 utc-2019 october 1 15:00 utc). trigg... | search for gravitational waves associated with fast radio bursts detected by chime/frb during the ligo-virgo observing run o3a |
the global 21-cm signal from cosmic dawn (cd) and the epoch of reionization (eor), at redshifts z ∼ 6-30, probes the nature of first sources of radiation as well as physics of the inter-galactic medium (igm). given that the signal is predicted to be extremely weak, of wide fractional bandwidth, and lies in a frequency ... | saras 2: a spectral radiometer for probing cosmic dawn and the epoch of reionization through detection of the global 21-cm signal |
this paper presents the results of the largest very long baseline interferometry (vlbi) absolute astrometry campaign to date of 13,645 radio source observations with the very long baseline array. of these, 7220 have been detected, including 6755 target sources that have never been observed with vlbi before. this makes ... | the wide-field vlba calibrator survey: wfcs |
the extraordinary physical resolution afforded by the event horizon telescope has opened a window onto the astrophysical phenomena unfolding on horizon scales in two known black holes, m87* and sgr a*. however, with this leap in resolution has come a new set of practical complications. sgr a* exhibits intraday variabil... | characterizing and mitigating intraday variability: reconstructing source structure in accreting black holes with mm-vlbi |
optical time-domain astronomy has grown rapidly in the past decade, but the dynamic infrared sky is rarely explored. aiming to construct a sample of mid-infrared outbursts in nearby galaxies (mirong), we have conducted a systematical search of low-redshift (z < 0.35) sloan digital sky survey spectroscopic galaxies t... | mid-infrared outbursts in nearby galaxies (mirong). i. sample selection and characterization |
the low-temperature reaction between cn and benzene (c6h6) is of significant interest in the astrochemical community due to the recent detection of benzonitrile, the first aromatic molecule identified in the interstellar medium (ism) using radio astronomy. benzonitrile is suggested to be a low-temperature proxy for ben... | benzonitrile as a proxy for benzene in the cold ism: low-temperature rate coefficients for cn + c6h6 |
gravitational-wave (gw) astronomy offers the potential to probe the wave-optics regime of gravitational lensing. wave-optics (wo) effects are relevant at low frequencies, when the wavelength is comparable to the characteristic lensing time delay multiplied by the speed of light, and are thus often negligible for electr... | lensing of gravitational waves: efficient wave-optics methods and validation with symmetric lenses |
we present results from a search for a radio transient associated with the ligo/virgo source s190814bv, a likely neutron star-black hole (nsbh) merger, with the australian square kilometre array pathfinder. we imaged a 30 deg2 field at δt = 2, 9, and 33 days post-merger at a frequency of 944 mhz, comparing them to refe... | an askap search for a radio counterpart to the first high-significance neutron star-black hole merger ligo/virgo s190814bv |
highly magnetized neutron stars are promising candidates to explain some of the most peculiar astronomical phenomena, for instance, fast radio bursts, gamma-ray bursts, and superluminous supernovae. pulsations of these highly magnetized neutron stars are also speculated to produce detectable gravitational waves. in add... | oscillations of highly magnetized non-rotating neutron stars |
we study the behavior of internal signal chain reflections and antenna cross coupling as systematics for 21 cm cosmological surveys. we outline the mathematics for how these systematics appear in interferometric visibilities and describe their phenomenology. we then describe techniques for modeling and removing these s... | mitigating internal instrument coupling for 21 cm cosmology. i. temporal and spectral modeling in simulations |
the central 0.1 parsecs of the milky way host a supermassive black hole identified with the position of the radio and infrared source sagittarius a* (refs. 1,2), a cluster of young, massive stars (the s stars3) and various gaseous features4,5. recently, two unusual objects have been found to be closely orbiting sagitta... | a population of dust-enshrouded objects orbiting the galactic black hole |
dirty fireballs are a hypothesized class of relativistic massive-star explosions with an initial lorentz factor γinit below the γinit ~ 100 required to produce a long-duration gamma-ray burst (lgrb), but which could still produce optical emission resembling lgrb afterglows. here we present the results of a search for o... | cosmological fast optical transients with the zwicky transient facility: a search for dirty fireballs |
the next-generation very large array (ngvla) is an astronomical observatory planned to operate at centimeter wavelengths (25 to 0.26 centimeters, corresponding to a frequency range extending from 1.2 to 116 ghz). the observatory will be a synthesis radio telescope constituted of approximately 244 reflector antennas eac... | the ngvla reference design |
we discuss the icecube neutrino observatory, the on-going construction of the icecube upgrade, and plans for the future icecube-gen2 facility, which includes an extended deep-ice optical array, an ultra-high-energy radio array, and a surface detector array. | neutrino astronomy with the next generation icecube neutrino observatory |
machine learning techniques have been increasingly useful in astronomical applications over the last few years, for example in the morphological classification of galaxies. convolutional neural networks have proven to be highly effective in classifying objects in image data. in the context of radio-interferometric imag... | radio galaxy zoo: compact and extended radio source classification with deep learning |
radio waves are strongly scattered in the solar wind, so that their apparent sources seem to be considerably larger and shifted than the actual ones. since the scattering depends on the spectrum of density turbulence, a better understanding of the radio wave propagation provides indirect information on the relative den... | density fluctuations in the solar wind based on type iii radio bursts observed by parker solar probe |
we present alma ∼0"02 resolution observations of the nucleus of the nearby (∼14 mpc) type 2 active galactic nucleus ngc 1068 at hcn/hco+/hnc j = 3-2 lines, as well as at their 13c isotopologue and vibrationally excited lines, to scrutinize the morphological, dynamical, chemical, and physical properties of dense molecul... | alma 0"02 resolution observations reveal hcn-abundance-enhanced counter-rotating and outflowing dense molecular gas at the ngc 1068 nucleus |
while most of the known debris discs present cold dust at tens of astronomical unit (au), a few young systems exhibit hot dust analogous to the zodiacal dust. η corvi is particularly interesting as it is old and it has both, with its hot dust significantly exceeding the maximum luminosity of an in situ collisional casc... | alma observations of the η corvi debris disc: inward scattering of co-rich exocomets by a chain of 3-30 m⊕ planets? |
as the largest radio telescope in the world, the square kilometre array (ska) will lead the next generation of radio astronomy. the feats of engineering required to construct the telescope array will be matched only by the techniques developed to exploit the rich scientific value of the data. to drive forward the devel... | square kilometre array science data challenge 1: analysis and results |
we report the detection of the oxygen-bearing complex organic molecules propenal (c2h3cho), vinyl alcohol (c2h3oh), methyl formate (hcooch3), and dimethyl ether (ch3och3) toward the cyanopolyyne peak of the starless core tmc-1. these molecules were detected through several emission lines in a deep q-band line survey of... | o-bearing complex organic molecules at the cyanopolyyne peak of tmc-1: detection of c2h3cho, c2h3oh, hcooch3, and ch3och3 |
the event horizon telescope (eht) has produced images of the plasma flow around the supermassive black holes in sgr a* and m87* with a resolution comparable to the projected size of their event horizons. observations with the next-generation event horizon telescope (ngeht) will have significantly improved fourier plane... | multifrequency black hole imaging for the next-generation event horizon telescope |
we introduce comap-eor, the next generation of the carbon monoxide mapping array project aimed at extending co intensity mapping to the epoch of reionization. comap-eor supplements the existing 30 ghz comap pathfinder with two additional 30 ghz instruments and a new 16 ghz receiver. this combination of frequencies will... | comap early science. vii. prospects for co intensity mapping at reionization |
atomic heterodyne dressed by a local oscillator resonant with rydberg transitions allows high sensitivity and robust phase measurement of a microwave electric field, but it is typically limited to detection of discrete frequencies within the narrow bandwidth of rydberg transitions. here we demonstrate an atomic heterod... | continuous-frequency microwave heterodyne detection in an atomic vapor cell |
if primordial black holes of script o(1-100) msolar constitute a significant portion of the dark matter in the universe, they should be very abundant in our galaxy. we present here a detailed analysis of the radio and x-ray emission that these objects are expected to produce due to the accretion of gas from the interst... | multi-wavelength astronomical searches for primordial black holes |
the breakthrough listen initiative is undertaking a comprehensive search for radio and optical signatures from extraterrestrial civilizations. an integral component of the project is the design and implementation of wide-bandwidth data recorder and signal processing systems. the capabilities of these systems, particula... | the breakthrough listen search for intelligent life: a wideband data recorder system for the robert c. byrd green bank telescope |
the volume of research on fast radio bursts (frbs) observation have been seeing a dramatic growth. to facilitate the systematic analysis of the frb population, we established a database platform, blinkverse, as a central inventory of frbs from various observatories and with published properties, particularly dynamic sp... | blinkverse: a database of fast radio bursts |
we report on a search for artificial narrowband signals of 20 stars within the restricted earth transit zone (retz) as a part of the ten-year breakthrough listen (bl) search for extraterrestrial intelligence (eti). the retz is the region of the sky from which an observer would see earth transit the sun with an impact p... | the breakthrough listen search for intelligent life: a 3.95-8.00 ghz search for radio technosignatures in the restricted earth transit zone |
we summarize the second radio synchrotron background workshop, which took place on 2022 june 15-17 in barolo, italy. this meeting was convened because available measurements of the diffuse radio zero level continue to suggest that it is several times higher than can be attributed to known galactic and extragalactic sou... | the second radio synchrotron background workshop: conference summary and report |
the origin(s) and mechanism(s) of fast radio bursts (frbs), which are short radio pulses from cosmological distances, have remained a major puzzle since their discovery. we report a strong quasi-periodic oscillation (qpo) of ~40 hz in the x-ray burst from the magnetar sgr j1935+2154 and associated with frb 200428, sign... | quasi-periodic oscillations of the x-ray burst from the magnetar sgr j1935-2154 and associated with the fast radio burst frb 200428 |
the joint detection of gravitational waves (gws) and electromagnetic (em) radiation from the binary neutron star merger gw170817 ushered in a new era of multi-messenger astronomy. joint gw-em observations can be used to measure the parameters of the binary with better precision than either observation alone. here, we u... | measuring the viewing angle of gw170817 with electromagnetic and gravitational waves |
we present the first high-resolution, simultaneous observations of the solar chromosphere in the optical and millimeter wavelength ranges, obtained with the atacama large millimeter array (alma) and the interferometric bidimensional spectrometer at the dunn solar telescope. in this paper we concentrate on the compariso... | solar chromospheric temperature diagnostics: a joint alma-hα analysis |
context. the common astronomy software application (casa) software suite, which is a state-of-the-art package for radio astronomy, can now reduce very long baseline interferometry (vlbi) data with the recent addition of a fringe fitter.aims: here, we present the radboud pipeline for the calibration of high angular reso... | rpicard: a casa-based calibration pipeline for vlbi data. calibration and imaging of 7 mm vlba observations of the agn jet in m 87 |
we report three new frbs discovered by the five-hundred-meter aperture spherical radio telescope (fast), namely frb 181017.j0036+11, frb 181118, and frb 181130, through the commensal radio astronomy fast survey (crafts). together with frb 181123, which was reported earlier, all four fast-discovered frbs share the same ... | crafts for fast radio bursts: extending the dispersion-fluence relation with new frbs detected by fast |
fast radio bursts (frbs) have a story which has been told and retold many times over the past few years as they have sparked excitement and controversy since their pioneering discovery in 2007. the frb class encompasses a number of microsecond- to millisecond-duration pulses occurring at galactic to cosmological distan... | a decade and a half of fast radio burst observations |
we report characterization results for an engineering prototype of a next-generation low-frequency radio astronomy array. this prototype, which we refer to as the aperture array verification system 0.5 (aavs0.5), is a sparse pseudo-random array of 16 log-periodic antennas designed for 70-450 mhz. it is co-located with ... | characterization of a low-frequency radio astronomy prototype array in western australia |
we report the development of the new 4-beam, 2-polarization, 2-sideband, 100 ghz band sis receiver "forest" (four beam receiver system on the 45-m telescope) and the results from commissioning and observations on the nobeyama 45-m telescope operated by nobeyama radio observatory, a branch of national astronomical obser... | development of the new multi-beam 100 ghz band sis receiver forest for the nobeyama 45-m telescope |
we present atacama large millimeter/submillimeter array observations of the ~10,000 au environment surrounding 21 protostars in the orion a molecular cloud tracing outflows. our sample is composed of class 0 to flat-spectrum protostars, spanning the full ~1 myr lifetime. we derive the angular distribution of outflow mo... | the evolution of protostellar outflow cavities, kinematics, and angular distribution of momentum and energy in orion a: evidence for dynamical cores |
it is now clear that a significant population of accreting black holes are undetected by commonly employed optical, mid-infrared color, x-ray, and radio selection methods as a result of obscuration or contamination of the emission from the nuclear region caused by star formation in the host galaxy. these elusive active... | the diagnostic potential of jwst in characterizing elusive agns |
china's chang'e-4 (ce-4) mission is the first human lander/rover mission on the far side of the moon. its probe is composed of a lander, rover, and the queqiao relay satellite. queqiao was successfully launched on may 21, 2018, and entered the halo orbit of the l2 point on june 14, becoming the first satellite connecti... | overview of the chang'e-4 mission: opening the frontier of scientific exploration of the lunar far side |
we present the design and implementation of an automated data calibration and reduction pipeline for very long baseline interferometric (vlbi) observations taken at millimeter wavelengths. these short radio wavelengths provide the best imaging resolution available from ground-based vlbi networks such as the event horiz... | eht-hops pipeline for millimeter vlbi data reduction |
a core collapse supernova occurs when exothermic fusion ceases in the core of a massive star, which is typically caused by exhaustion of nuclear fuel. theory predicts that fusion could be interrupted earlier by merging of the star with a compact binary companion. we report a luminous radio transient, vt j121001+495647,... | a transient radio source consistent with a merger-triggered core collapse supernova |
the recent availability of high-resolution far-infrared (fir) polarization observations of galaxies using hawc+/sofia has facilitated studies of extragalactic magnetic fields in the cold and dense molecular disks. we investigate whether any significant structural differences are detectable in the kiloparsec-scale magne... | extragalactic magnetism with sofia (legacy program). i. the magnetic field in the multiphase interstellar medium of m51 |
the devonian frasnian-famennian (f-f) boundary marks one of the five main extinction intervals of the phanerozoic aeon. this time was characterized by two pulses of oceanic anoxia, named the lower and upper kellwasser events, during which massive marine biodiversity losses occurred. this paper presents high-resolution ... | anchoring the late devonian mass extinction in absolute time by integrating climatic controls and radio-isotopic dating |
the recent ligo-virgo detection of gravitational waves from a binary neutron star inspiral event gw170817 and the discovery of its accompanying electromagnetic signals mark a new era for multimessenger astronomy. in the coming years, advanced gravitational-wave detectors are likely to detect tens to hundreds of similar... | inferring the population properties of binary neutron stars with gravitational-wave measurements of spin |
the fast developments of radio astronomy open a new window to explore the properties of dark matter (dm). the recent direct imaging of the supermassive black hole (smbh) at the center of m87 radio galaxy by the event horizon telescope (eht) collaboration is expected to be very useful to search for possible new physics.... | constraints on dark matter annihilation from the event horizon telescope observations of m87* |
the collaboration for astronomy signal processing and electronics research (casper) has been working for a decade to reduce the time and cost of designing, building and deploying new digital radio-astronomy instruments. today, casper open-source technology powers over 45 scientific instruments worldwide, and is used by... | a decade of developing radio-astronomy instrumentation using casper open-source technology |
we present atacama large millimeter/submillimeter array (alma) cycle 5 and cycle 6 observations of co (2-1) and co (3-2) emission at 0"2-0"3 resolution in two radio-bright, brightest group/cluster early-type galaxies, ngc 315 and ngc 4261. the data resolve co emission that extends within their black hole (bh) spheres o... | black hole mass measurements of radio galaxies ngc 315 and ngc 4261 using alma co observations |
context. extended radio sources in the sky require a dense sampling of short baselines to be properly imaged by interferometers. this problem arises in many areas of radio astronomy, such as in the study of galaxy clusters, which may host megaparsec-scale diffuse synchrotron sources in the form of radio halos. in clust... | the planck clusters in the lofar sky. ii. lotss-dr2: recovering diffuse extended emission with lofar |
dust particle sizes constrained from dust continuum and polarization observations by radio interferometry are inconsistent by at least an order of magnitude. motivated by porous dust observed in small solar system bodies (e.g., from the rosetta mission), we explore how the dust particle's porosity affects the estimated... | porous dust particles in protoplanetary disks: application to the hl tau disk |
the farside of the moon is a pristine, quiet platform to conduct low radio frequency observations of the early universe's dark ages, as well as space weather and magnetospheres associated with habitable exoplanets. in this paper, the astrophysics associated with nasa-funded concept studies will be described including a... | transformative science from the lunar farside: observations of the dark ages and exoplanetary systems at low radio frequencies |
we present submillimeter array observations of seven massive molecular clumps that are dark in the far-infrared for wavelengths up to 70 μm. our 1.3 mm continuum images reveal 44 dense cores, with gas masses ranging from 1.4 to 77.1 m ⊙. twenty-nine dense cores have masses greater than 8 m ⊙ and the other 15 dense core... | formation of massive protostellar clusters—observations of massive 70 μm dark molecular clouds |
by linking widely separated radio dishes, the technique of very long baseline interferometry (vlbi) can greatly enhance angular resolution in radio astronomy. however, at any given moment, a vlbi array only sparsely samples the information necessary to form an image. conventional imaging techniques partially overcome t... | dynamical imaging with interferometry |
we report here radio follow-up observations of the optical tidal disruption event (tde) at 2019azh. previously reported x-ray observations of this tde showed variability at early times and a dramatic increase in luminosity, by a factor of ~10, about 8 months after optical discovery. the x-ray emission is mainly dominat... | a late-time radio flare following a possible transition in accretion state in the tidal disruption event at 2019azh |
the population of artificial satellites and space debris orbiting the earth imposes non-negligible constraints on both space operations and ground-based optical and radio astronomy. the ongoing deployment of several satellite 'mega-constellations' in the 2020s represents an additional threat that raises significant con... | the proliferation of space objects is a rapidly increasing source of artificial night sky brightness |
context. the role of large-scale magnetic fields in the evolution of star-forming regions remains elusive. its investigation requires the observational characterization of well-constrained molecular clouds. the monoceros ob 1 molecular cloud is a large complex containing several structures that have been shown to be en... | large-scale magnetic field in the monoceros ob 1 east molecular cloud |
we present the power spectrum methodology used for the first-season comap analysis, and assess the quality of the current data set. the main results are derived through the feed-feed pseudo-cross-spectrum (fpxs) method, which is a robust estimator with respect to both noise modeling errors and experimental systematics.... | comap early science. iv. power spectrum methodology and results |
the five-hundred-meter aperture spherical radio telescope (fast) is a chinese megascience project funded by the national development and reform commission (ndrc) of the people's republic of china. the national astronomical observatories of china (naoc) is in charge of its construction and subsequent operation. upon its... | the five-hundred-meter aperture spherical radio telescope project |
the missing baryon problem is one of the major unsolved problems in astronomy. fast radio bursts (frbs) are bright millisecond pulses with unknown origins. the dispersion measure of frbs is defined as the electron column density along the line of sight, and accounts for every ionized baryon. here we measure the baryon ... | finding the missing baryons in the intergalactic medium with localized fast radio bursts |
we consider the energy budgets and radiative history of eight fading active galactic nuclei (agns), identified from an energy shortfall between the requirements to ionize very extended (radius > 10 kpc) ionized clouds and the luminosity of the nucleus as we view it directly. all show evidence of significant fading o... | fading agn candidates: agn histories and outflow signatures |
we propose to use graphene-based josephson junctions (gjjs) to detect single photons in a wide electromagnetic spectrum from visible to radio frequencies. our approach takes advantage of the exceptionally low electronic heat capacity of monolayer graphene and its constricted thermal conductance to its phonon degrees of... | graphene-based josephson-junction single-photon detector |
we describe a novel method to compute the components of dynamo tensors from direct magnetohydrodynamic (mhd) simulations. our method relies upon an extension and generalisation of the standard högbom clean algorithm widely used in radio astronomy to systematically remove the impact of the strongest beams onto the corre... | iterative removal of sources to model the turbulent electromotive force |
we present the results of models that were designed to study all possible water maser transitions in the frequency range 0-1.91 thz, with particular emphasis on maser transitions that may be generated in evolved-star envelopes and observed with the alma and sofia telescopes. we used tens of thousands of radiative trans... | the physics of water masers observable with alma and sofia: model predictions for evolved stars |
fast radio bursts (frbs) are millisecond-time-scale bursts of coherent radio emission that are luminous enough to be detectable at cosmological distances. in this review, i describe the discovery of frbs, subsequent advances in understanding them, and future prospects. thousands of potentially observable frbs reach ear... | the discovery and scientific potential of fast radio bursts |
we present k-band (24 ghz) images of 731 compact extragalactic radio sources with submilliarcsecond resolution, based on radio interferometric observations made with the very long baseline array of 10 telescopes during 29 day long sessions spanning from 2015 to 2018 and recorded at 2048 mbps. many of these sources are ... | the celestial reference frame at k band: imaging. i. the first 28 epochs |
because of the ultra-low photon energies in the mid-infrared and terahertz frequencies, in these bands photodetectors are notoriously underdeveloped, and broadband single photon detectors (spds) are non-existent. advanced spds exploit thermal effects in nano-structured superconductors, and their performance is currentl... | magic-angle bilayer graphene nanocalorimeters: toward broadband, energy-resolving single photon detection |
linear carbon chains are common in various types of astronomical molecular sources. possible formation mechanisms involve both bottom-up and top-down routes. we have carried out a combined observational and modeling study of the formation of carbon chains in the c-star envelope irc +10216, where the polymerization of a... | growth of carbon chains in irc +10216 mapped with alma |
we present a set of peculiar radio sources detected using an unsupervised machine learning method. we use data from the australian square kilometre array pathfinder (askap) telescope to train a self-organizing map (som). the radio maps from three askap surveys, evolutionary map of universe pilot survey (emu-ps), deep i... | discovery of peculiar radio morphologies with askap using unsupervised machine learning |
the spin of the supermassive black hole that resides at the galactic center can, in principle, be measured by accurate measurements of the orbits of stars that are much closer to sgr a* than s2, the orbit of which recently provided the measurement of the gravitational redshift and the schwarzschild precession. the grav... | detection of faint stars near sagittarius a* with gravity |
we report the detection in tmc-1 of the cation hccs+ (x̃ 3σ−), which is the protonated form of the widespread radical ccs. this is the first time that a protonated radical has been detected in a cold dark cloud. twenty-six hyperfine components from twelve rotational transitions have been observed with the yebes 40 m an... | discovery of the elusive thioketenylium, hccs+, in tmc-1 |
the arcminute microkelvin imager (ami) telescopes located at the mullard radio astronomy observatory near cambridge have been significantly enhanced by the implementation of a new digital correlator with 1.2 mhz spectral resolution. this system has replaced a 750-mhz resolution analogue lag-based correlator, and was de... | a digital correlator upgrade for the arcminute microkelvin imager |
at radio wavelengths, scattering in the interstellar medium distorts the appearance of astronomical sources. averaged over a scattering ensemble, the result is a blurred image of the source. however, narayan & goodman and goodman & narayan showed that for an incomplete average, scattering introduces refractive ... | theory and simulations of refractive substructure in resolved scatter-broadened images |
this paper presents the nonhomogeneous poisson process (nhpp) for modeling the rate of fast radio bursts (frbs) and other infrequently observed astronomical events. the nhpp, well-known in statistics, can model the dependence of the rate on both astronomical features and the details of an observing campaign. this is pa... | the nonhomogeneous poisson process for fast radio burst rates |
we present the hubble deep uv legacy survey (hduv), a 132-orbit imaging program with the wfc3/uvis camera on board the hubble space telescope (hst). the hduv extends and builds on the few previous uv imaging surveys in the two goods/candels-deep fields to provide deep images over a total area of ∼100 arcmin2 in the two... | hduv: the hubble deep uv legacy survey |
context. the ionosphere is the main driver of a series of systematic effects that limit our ability to explore the low-frequency (<1 ghz) sky with radio interferometers. its effects become increasingly important towards lower frequencies and are particularly hard to calibrate in the low signal-to-noise ratio (s/n) r... | the effect of the ionosphere on ultra-low-frequency radio-interferometric observations |
coronal mass ejections (cmes) are large eruptions of plasma and magnetic field from the low solar corona into interplanetary space. these eruptions are often associated with the acceleration of energetic electrons which produce various sources of high intensity plasma emission. in relatively rare cases, the energetic e... | estimation of a coronal mass ejection magnetic field strength using radio observations of gyrosynchrotron radiation |
rm-tools analyzes radio polarization data, specifically the use of faraday rotation measure synthesis and stokes qu model fitting. it contains routines for both single-pixel 1d polarized spectra as well as 3d polarization cubes. rm-tools is intended to serve as a toolkit for studies of polarized radio sources and measu... | rm-tools: rotation measure (rm) synthesis and stokes qu-fitting |
this article aims to highlight the impact for ground based astronomical observations in different windows of the electromagnetic spectrum coming from the deployment of fleets of telecommunications satellites. a particular attention is given to the problem of crowding of circumterrestrial space by medium/small size orbi... | concerns about ground based astronomical observations: a step to safeguard the astronomical sky |
context. the low frequency array (lofar) is the only existing radio interferometer able to observe at ultra-low frequencies (<100 mhz) with high resolution (<15") and high sensitivity (<1 mjy beam−1). to exploit these capabilities, the lofar surveys key science project is using the lofar low band antenna (lba)... | the lofar lba sky survey. ii. first data release |
observations of low-order 12c16o transitions represent the most direct way to study galaxies' cold molecular gas, the fuel of star formation. here we present the first detection of co(j = 2 → 1) in a galaxy lying on the main-sequence of star-forming galaxies at z > 6. our target, g09-83808 at z = 6.03, has a short d... | probing cold gas in a massive, compact star-forming galaxy at z = 6 |
modern dual-polarization receivers allow a radio telescope to characterize the full polarization state of incoming interstellar radio waves. many astronomers incorrectly consider a polarimeter to be the "backend" of the telescope. we go to lengths to dissuade the reader of this concept: the backend is the least complic... | the measurement of polarization in radio astronomy |
we investigate the cold and warm gas content, kinematics, and spatial distribution of six local massive elliptical galaxies to probe the origin of the multiphase gas in their atmospheres. we report new observations, including stratospheric observatory for infrared astronomy [c ii], atacama large millimeter/submillimete... | probing multiphase gas in local massive elliptical galaxies via multiwavelength observations |
the james webb space telescope time-domain field (jwst-tdf) is an ~14' diameter field near the north ecliptic pole that will be targeted by one of the jwst guaranteed time observations programs. here, we describe our james clerk maxwell telescope scuba-2 850 μm imaging of the jwst-tdf and present the submillimeter sour... | the jcmt scuba-2 survey of the james webb space telescope north ecliptic pole time-domain field |
the origins of fast radio bursts (frbs), astronomical transients with millisecond time-scales, remain unknown. one of the difficulties stems from the possibility that observed frbs could be heterogeneous in origin; as some of them have been observed to repeat, and others have not. due to limited observing periods and t... | uncloaking hidden repeating fast radio bursts with unsupervised machine learning |
new mass-produced, wide-field, small-aperture telescopes have the potential to revolutionize ground-based astronomy by greatly reducing the cost of collecting area. in this paper, we introduce a new class of large telescope based on these advances: an all-sky, arcsecond-resolution, 1000 telescope array which builds a s... | low-cost access to the deep, high-cadence sky: the argus optical array |
we combine recent simulation work on the sfr-[c ii] correlation at high redshift with empirical modeling of the galaxy-halo connection (via universemachine) to forecast [c ii] auto power spectra from z ∼ 4 to z ∼ 8. we compare these to sensitivities realistically expected from various instruments expected to come onlin... | forecasting [c ii] line-intensity mapping measurements between the end of reionization and the epoch of galaxy assembly |
cyclostratigraphy is an important tool for understanding astronomical climate forcing and for reconstructing geological time in sedimentary sequences, provided that an imprint of insolation variations caused by earth's orbital eccentricity, obliquity and precession is preserved (milankovitch forcing). understanding ast... | ordovician cyclostratigraphy and astrochronology |
we present comprehensive multiwavelength radio to x-ray observations of grb 181201a spanning from ≈150 s to ≈163 days after the burst, comprising the first joint alma-vla-gmrt observations of a gamma-ray burst (grb) afterglow. the radio and millimeter-band data reveal a distinct signature at ≈3.9 days, which we interpr... | a reverse shock in grb 181201a |
we present the results of atacama large millimeter/submillimeter array (alma) band 3 observations of the nearby type ic supernova (sn) 2020oi. under the standard assumptions on the sn-circumstellar medium (csm) interaction and the synchrotron emission, the data indicate that the csm structure deviates from a smooth dis... | the final months of massive star evolution from the circumstellar environment around sn ic 2020oi |
we present yebes 40 m telescope observations of the three most stable c4h3n isomers towards the cyanopolyyne peak of tmc-1. we have detected 13 transitions from ch3c3n (a and e species), 16 lines from ch2cchcn, and 27 lines (a-type and b-type) from hccch2cn. we thus provide a robust confirmation of the detection of hcc... | a study of c4h3n isomers in tmc-1: line by line detection of hccch2cn |
the exploration of the cosmic dawn, the period of the universe during which the first stars and galaxies were formed, is one of the last frontiers of modern astronomy and cosmology. the redshifted 21-cm line emission from neutral hydrogen is a unique probe and can open this era for astrophysical and cosmological studie... | exploring the cosmic dawn with nenufar |
locating gamma-ray transients including gamma-ray bursts (grbs) and soft gamma repeater (sgr) bursts is of great importance in multi-messenger and multi-wavelength astronomy, such as guiding optical and radio follow-up observations and evaluating the association of a grb with a gravitational wave or an sgr with a galax... | enhanced localization of transients based on a novel cross-correlation method |
current and future astronomical survey facilities provide a remarkably rich opportunity for transient astronomy, combining unprecedented fields of view with high sensitivity and the ability to access previously unexplored wavelength regimes. this is particularly true of lofar, a recently-commissioned, low-frequency rad... | the lofar transients pipeline |
recent observations of global velocity gradients across and along molecular filaments have been interpreted as signs of gas accreting onto and along these filaments, potentially feeding star-forming cores and protoclusters. the behavior of velocity gradients in filaments, however, has not been studied in detail, partic... | velocity-coherent filaments in ngc 1333: evidence for accretion flow? |
the weizmann fast astronomical survey telescope is a 55 cm optical survey telescope with a high-cadence (25 hz) monitoring of the sky over a wide field of view (≈7 deg2). the high frame rate allows detection of sub-second transients over multiple images. we present a sample of ~0.1-0.3 s duration flares detected in an ... | a high-rate foreground of sub-second flares from geosynchronous satellites |
we report the discovery of a highly dispersed fast radio burst (frb), frb 181123, from an analysis of ∼1500 hr of drift scan survey data taken using the five-hundred-meter aperture spherical radio telescope (fast). the pulse has three distinct emission components, which vary with frequency across our 1.0-1.5 ghz observ... | a fast radio burst discovered in fast drift scan survey |
the response of the antenna is a source of uncertainty in measurements with the experiment to detect the global epoch of reionization signature (edges). we aim to validate the electromagnetic beam model of the low-band (50-100 mhz) dipole antenna with comparisons between models and against data. we find that simulation... | validation of the edges low-band antenna beam model |
we present narrow- and medium-band hubble space telescope imaging, with additional supporting ground-based imaging, spectrophotometry, and fabry-perot interferometric data, for eight galaxies identified as hosting a fading active galactic nucleus (agn). these are selected to have agn-ionized gas projected \gt 10 kpc fr... | hst imaging of fading agn candidates. i. host-galaxy properties and origin of the extended gas |
we present resolve, a new algorithm for radio aperture synthesis imaging of extended and diffuse emission in total intensity. the algorithm is derived using bayesian statistical inference techniques, estimating the surface brightness in the sky assuming a priori log-normal statistics. resolve estimates the measured sky... | resolve: a new algorithm for aperture synthesis imaging of extended emission in radio astronomy |
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