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the detection of mjy/sub-mjy point sources is a significant challenge for single-dish radio telescopes. detection or upper limits on the faint afterglow from grbs or other sources at cosmological distances are important means of constraining the source modeling. using the sardinia radio telescope (srt), we compare the ... | methods for detection and analysis of weak radio sources with single-dish radio telescopes |
a new camera is being developed for the large millimeter telescope (sierra negra, méxico) by an international collaboration with the university of massachusetts, the university of cardiff, and arizona state university. the camera is based on kinetic inductance detectors (kids), a very promising technology due to their ... | design of a 2-mm wavelength kids prototype camera for the large millimeter telescope |
magnetic reconnection in solar flares can efficiently generate nonthermal electron beams. the energetic electrons can, in turn, cause radio waves through microscopic plasma instabilities as they propagate through the ambient plasma along the magnetic field lines. we aim at investigating the wave emission caused by fast... | wave emission of nonthermal electron beams generated by magnetic reconnection |
the real-time fast fourier transform (fft) is the essential algorithm for signal processing in a solar radio receiver. however, field-programmable gate array (fpga) computation resources have become the limitation of real-time processing of signals with increasing time and spectral resolutions. it is necessary to desig... | a new multichannel parallel real-time fft algorithm for a solar radio observation system based on fpga |
in this paper, the performance characteristics of a horizontal symmetrical dipole antenna, located in the immediate vicinity of the moon’s surface, are numerically analyzed. the lunar soil is assumed as a flat-layered medium composed of two lossy dielectrics, the upper layer with a thickness of 5-10m, filled with regol... | parameters of a short dipole antenna placed over a two-layer lunar soil |
paper xvii. x-ray and sunyaev-zel'dovich properties of the redshift 2.0 galaxy cluster xlssc 122. we present results from a 100ks xmm-newton observation of galaxy cluster xlssc 122, the first massive cluster discovered through its x-ray emission at z~2. the data provide the first precise constraints on the bulk thermod... | vizier online data catalog: xxl survey. dr2 (chiappetti+, 2018) |
we present the main performance aspects of the sensitivity and dynamic range of the square kilometre array (ska). the sensitivity and dynamic range of a radio astronomy interferometer are affected by different sources of errors and noises. a general description of these effects is given, focusing on the direction-indep... | assessment of the performance impact of direction-independent effects in the square kilometre array |
a 180° hybrid and a directional coupler to be employed in the p-band cryogenic receiver of the sardinia radio telescope are proposed in this work. an in-depth study of the issues related to the use of microwave components for cryogenic radio astronomy receivers is carried out to select the best suited technology and co... | high-performance cryogenic fractal 180° hybrid power divider with integrated directional coupler |
we have observed the three low-mass protostars, iras 15398-3359, l1527 irs, and tmc-1a, with the alma 12 m array, the aca 7 m array, and the iram-30 m and apex telescopes in the c18o j = 2-1 emission. overall, the c18o emission shows clear velocity gradients at radii of ~100-1000 au, which likely originate from the rot... | probing velocity structures of protostellar envelopes: infalling and rotating envelopes within turbulent dense cores |
a multi-function digital baseband data acquisition system is designed for the sampling, distribution and recording of wide-band multi-channel astronomical signals. the system hires a snap2 board as a digital baseband converter to digitize, channelize and packetize the received signal. it can be configured dynamically f... | design of a multi-function high-speed digital baseband data acquisition system |
in astronomical observations, the radio frequency interference (rfi) will cause pseudo spectra and reduce the reliability and validity of observational data. the rfi mitigation, which includes many technical innovations of devices and the method studies of data processing, aims at reducing the influence of rfi on the r... | research on receiver anti-rfi of delingha 13.7 m telescope |
at first, the receiving system of the tianma 65m radio telescope (tm65m in brief) and its noise characteristics at the l, s, c, and x four frequency bands are described. then, a few measuring methods of system noise temperature are discussed, and the major factors affecting the noise temperature measurement are analyze... | the measurement and analysis of system noise temperatures of the tm65m radio telescope at low frequency bands1,2 |
ratan-600 is the largest radio telescope in the world with a variable profile ring antenna 600 m in diameter. due to its wide free-aberration zone it is possible to get instantaneous radio spectra of cosmic objects in the frequency range 1-22 ghz during 2-3 min. almost all telescope time is spent on the astrophysical t... | ratan-600 radio telescope: observing programs and outlook |
the first results of direct expedition measurements of atmospheric absorption of electromagnetic waves in the sub-terahertz frequency range of 0.1-1 thz, carried out in order to select an optimal site from the point of view of the microwave astroclimate for development of an observatory that can become an element of th... | direct measurements of atmospheric absorption of subterahertz waves in the northern caucasus |
we present new molecular modeling for 14no and 15no and a deep, blind molecular line survey at low radio frequencies (99-129 mhz). this survey is the third in a series completed with the murchison widefield array (mwa), but in comparison with the previous surveys, uses 4 times more data (17 hr versus 4 hr) and is 3 tim... | nitric oxide and other molecules: molecular modeling and low-frequency exploration using the murchison widefield array |
the mexican array radio telescope (mexart) is a transit instrument mainly dedicated to performing interplanetary scintillation (ips) observations with a central operating frequency of 139.65 mhz. the main scientific objective is to perform studies of solar wind properties and space weather effects. mexart initially ope... | first observations of the new mexart's digital system |
context. polarimetric images of circumstellar environments, even when corrected with adaptive optics, have a limited angular resolution. finite resolution greatly affects polarimetric images because of the canceling of adjacent polarization signals with opposite signs. in radio astronomy this effect is called beam depo... | polarimetric imaging of circumstellar disks. i. artifacts due to limited angular resolution |
a new imaging tool for radio interferometry has been developed based on the sparse modeling approach. it has been implemented as a python module operating on common astronomy software applications (casa) so that the tool is able to process the data taken by atacama large millimeter/submillimeter array (alma). in order ... | a new synthesis imaging tool for alma based on sparse modeling |
electronic noise, or stochasticity in the current, voltage, and frequency of a carrier signal is caused by microscopic fluctuations in the occupation of quantum electronic states. in the context of scientific instrumentation, understanding the physical origin of these fluctuations is of paramount importance since the a... | investigation of electronic fluctuations in semiconductor materials and devices through first-principles simulations and experiments in transistor amplifiers |
the tunka radio extension (tunka-rex) is an antenna array consisting of 63 antennas at the location of the taiga facility (tunka advanced instrument for cosmic ray physics and gamma astronomy) in eastern siberia, nearby lake baikal. tunka-rex is triggered by the air-cherenkov array tunka-133 during clear and moonless w... | latest results of the tunka radio extension |
the far-field pattern of a geometrically large and complex antenna used in low-frequency radio astronomy is computationally expensive to simulate on electromagnetic simulators, such as feko. for example, one station of the square kilometer array, which consists of 256 log-periodic antenna elements, will take years to s... | optimizing processing time of radio-astronomy antenna simulations using feko |
from november 2017 to may 2019 at the astronomical observatory of odessa i.i. mechnikov national university, the variational component of the geomagnetic field was monitored to study short-periodic geomagnetic variations in the central part of the odessa regional magnetic anomaly. the measurements were carried out usin... | results of comparison of fast variations of geomagnetic field and ionospheric scintillations of 3c 144 radio source in the area of odessa geomagnetic anomaly |
this paper reports a design study for a space-based decametric wavelength telescope. while not a new concept, this design study focused on many of the operational aspects that would be required for an actual mission. this design optimized the number of spacecraft to insure good visibility of approx. 80% of the radio ga... | a space-based decametric wavelength radio telescope concept |
benzvalyne (c6h4) is a bicyclic structural isomer of o-benzyne that some typically trusted levels of theory do not report as a minimum on the potential energy surface (pes). the structure was found to be a c2v minimum at the mcscf, mp2, coupled-cluster single double, coupled-cluster single double triple (ccsdt)-1b, and... | benzvalyne: real or imaginary? |
the hyperfine transitions of the ground-rotational state of the hydroxyl radical (oh) have emerged as a versatile tracer of the diffuse molecular interstellar medium. we present a novel automated gaussian decomposition algorithm designed specifically for the analysis of the paired on-source and off-source optical depth... | amoeba: automated molecular excitation bayesian line-fitting algorithm |
though evidence for episodic accretion is now commonplace toward low mass protostars, the recent extraordinary outburst in the massive protostellar cluster ngc6334i (hunter et al. 2017) marks only the second large episodic accretion event observed toward a deeply embedded massive protostar and casts new light on the tu... | resolving the source of the massive protostellar accretion outburst in ngc6334i-mm1b |
polarization of radio emission from solar flares provides essential information about plasma regimes confined to magnetic field in quiescent, pre-explosion, sudden energy release and decay phases. observations of polarization are carried out continuously by the first time at two millimeter wavelengths of 6.67 and 3.34 ... | center-to-limb variation of solar bursts polarization at millimeter wavelengths |
we discuss potential science investigations at mid-latitudes enabled by a modern, space-weather-grade, ground-based radio-frequency (rf) network of scintillation receivers which encompasses global navigation satellite systems (gnss) and beacon receivers, along with coherent radars, and leveraging radio astronomy infras... | ground-based infrastructure for monitoring and characterizing intermediate-scale ionospheric irregularities at mid-latitudes |
we have conducted a 13co survey of a sample of 128 infrared color-selected intermediate-mass star-forming region (im sfr) candidates. we utilized the onsala 20 m telescope to observe 13co (1-0) toward 67 northern im sfrs, used the 12 m atacama pathfinder experiment telescope to observe 13co (2-1) toward 22 southern im ... | a 13co survey of intermediate-mass star-forming regions |
the jicamarca radio observatory (jro) main 50-mhz array antenna radar system with multiple receivers is being used to study meteors via two interferometric receiving modes. one of the major challenges in these studies is the phase calibration of the various receiver (interferometric) channels (legs). while investigatin... | phase and pattern calibration of the jicamarca radio observatory radar using satellites |
coronal mass ejections (cmes) may dramatically impact habitability and atmospheric composition of planets around magnetically active stars, including young solar analogs and many m dwarfs. theoretical predictions of such effects are limited by the lack of observations of stellar cmes. this thesis addresses this gap thr... | the search for stellar coronal mass ejections |
the analysis of syn-2-cyano-1,3-butadiene (c5h5n, μa = 3.2 d, μb = 2.3 d) in its ground vibrational state and two lowest-energy excited vibrational states, ν27 (a″, 144 cm-1) and ν19 (a', 163 cm-1), in the 130-360 ghz frequency region has been completed. nearly 4200 rotational transitions have been measured in the grou... | the 130-360 ghz rotational spectrum of syn-2-cyano-1,3-butadiene (c5h5n) - a molecule of astrochemical relevance |
ss433 is the first example of a microquasar discovered in the galaxy. it is a natural laboratory for studies of extraordinarily interesting physical processes that are very important for the relativistic astrophysics, cosmic gas dynamics and theory of evolution of stars. the object has been studied for over 40 years in... | progress in understanding the nature of ss433 |
detecting the eor will require extremely precise measurements. the signal is very faint and is obscured by intervening emission, or foregrounds, that are 4-5 orders of magnitude brighter. thus far, analyses have not achieved the precision required to measure the eor signal. calibration precision is a dominant limitatio... | enabling the next generation of 21 cm cosmology: precision analysis techniques for radio cosmology observations |
a new unambiguous, multibaseline interferometric technique was recently employed for meteor observations at jicamarca radio observatory (jro). these observations largely confirm high-altitude radar meteors (harms). the 50 mhz jro array is arranged in contiguous quarter-arrays (q) each of which is comprised of 4 × 4 sub... | high-altitude radar meteors observed at jicamarca radio observatory using a multibaseline interferometric technique |
large reflector antennas are widely used in radars, satellite communication, radio astronomy, and so on. the rapid developments in these fields have created demands for development of better performance and higher surface accuracy. however, low accuracy and low efficiency are the common disadvantages for traditional pa... | effect of facet displacement on radiation field and its application for panel adjustment of large reflector antenna |
selecting a good site for ground-based astronomy is very important. based on the era-interim global reanalysis data, this paper studied the atmospheric conditions of the qitai telescope (qtt) site from the aspects of absolute humidity, mixing ratio and precipitable water vapor (pwv). error estimations of meteorological... | research and application of reanalysis data for radio astronomical site testing |
chinese lunar spacecraft chang'e-3 (ce3) and chang'e5-t1 (ce5t1) were launched in 2013 and 2014, respectively and very long baseline interferometry (vlbi) observations were performed. signal to noise ratio (snr) of the tianma (tm) station experienced peculiar variation, whereas snrs of other stations were rather stable... | investigation on peculiar snr variation at tianma radio telescope |
this review focuses on the physics of gamma ray bursts probed through their radio afterglow emission. even though radio band is the least explored of the afterglow spectrum, it has played an important role in the progress of grb physics, specifically in confirming the hypothesized relativistic effects. currently radio ... | radio afterglows of gamma ray bursts |
the correlation between scattering and the dispersion measure of the crab nebula pulsar b0531+21, obtained earlier from observations made on the large phased array (lpa) at 111 mhz and at jodrell bank observatory, has been confirmed using new independent measurements at the pushchino radio astronomy observatory and jod... | relationship between scattering and dispersion measure of the crab nebula pulsar |
modern astronomical data processing requires complex software pipelines to process ever growing datasets. for radio astronomy, these pipelines have become so large that they need to be distributed across a computational cluster. this makes it difficult to monitor the performance of each pipeline step. to gain insight i... | pipeline collector: gathering performance data for distributed astronomical pipelines |
we investigated the chemical evolution of hc3n in six dense molecular clouds, using archival available data from the herschel infrared galactic plane survey (hi-gal) and the millimeter astronomy legacy team survey at 90 ghz (malt90). radio sky surveys of the multi-array galactic plane imaging survey (magpis) and the sy... | chemical evolution of hc3n in dense molecular clouds |
three new fast radio burst were detected with the radio telescope bsa lpi of the pushchino radio astronomy observatory of the lebedev physical institute (100 km south from moscow) at the frequency 111 mhz during processing of archival data of scintillation of radio source on inhomogeneities of interplanetary plasma in ... | first detection of frbs at the frequency 111 mhz at the radio telescope bsa lpi |
the physical motivations and advantages of the new gamma-observatory taiga (tunka advanced instrument for cosmic ray physics and gamma astronomy) is presented. the taiga array is a complex, hybrid detector for ground-based gamma-ray astronomy for energies from a few tev to several pev as well as for cosmic ray studies ... | the taiga experiment: from cosmic ray to gamma-ray astronomy in the tunka valley |
context. methylamine (ch3nh2) is a light molecule of astrophysical interest, which has an intensive rotational spectrum that extends in the submillimeter wave range and far beyond, even at temperatures characteristic for the interstellar medium. it is likely for 13c isotopologue of methylamine to be identified in astro... | millimeter and submillimeter wave spectra of 13c methylamine |
we conducted an observation of the nearby irregular galaxy ic 1613 with the chandra x-ray observatory using the s3 chip of the advanced ccd imaging spectrometer (acis) with an effective exposure time of 49.9 ks. the observation primarily targeted the extensive bubble and star formation region in the northeast quadrant ... | the x-ray-resolved supernova remnant s8 in the dwarf irregular galaxy ic 1613 |
time-domain radio astronomy utilizes a harmonic sum algorithm as part of the fourier domain periodicity search, this type of search is used to discover single pulsars. the harmonic sum algorithm is also used as part of the fourier domain acceleration search which aims to discover pulsars that are locked in orbit around... | a gpu implementation of the harmonic sum algorithm |
the advanced ligo and virgo experiments are poised to detect gravitational waves (gws) directly for the first time this decade. the ultimate prize will be joint observation of a compact binary merger in both gravitational and electromagnetic channels. however, gw sky locations that are uncertain by hundreds of square d... | the needle in the 100 deg2 haystack: the hunt for binary neutron star mergers with ligo and palomar transient factory |
as of 2023, the square kilometre array will constitute the world's largest radio telescope, offering unprecedented capabilities for a diverse science programme in radio astronomy. at the same time, the ska will be ideally suited to detect extensive air showers initiated by cosmic rays in the earth's atmosphere via thei... | high-precision measurements of extensive air showers with the ska |
we present a 67-93.6 ghz spectral line survey of orion-kl with the new 4 mm receiver on the green bank telescope (gbt). the survey reaches unprecedented depths and covers the low-frequency end of the 3 mm atmospheric window which has been relatively unexplored previously. the entire spectral-line survey is published el... | the gbt 67-93.6 ghz spectral line survey of orion-kl |
this paper presents the measured sensitivity of csiro's first mk. ii phased array feed (paf) on an askap antenna. the mk. ii achieves a minimum system-temperature-over-efficiency t_{sys}/η of 78 k at 1.23 ghz and is 95 k or better from 835 mhz to 1.8 ghz. this paf was designed for the australian ska pathfinder telescop... | measured sensitivity of the first mark ii phased array feed on an askap antenna |
the outer galaxy beyond the outer arm provides a good opportunity to study star formation in an environment significantly different from that in the solar neighborhood. however, star-forming regions in the outer galaxy have never been comprehensively studied or cataloged because of the difficulties in detecting them at... | star formation activity beyond the outer arm. i. wise-selected candidate star-forming regions |
radar observations provide crucial insights into the formation and dynamical evolution of comets. this ability is constrained by our knowledge of the dielectric and textural properties of these small-bodies. using several observations by rosetta as well as results from the earth-based arecibo radio telescope, we provid... | post-rendezvous radar properties of comet 67p/cg from the rosetta mission: understanding future earth-based radar observations and the dynamical evolution of comets |
multi-wavelength astronomical studies brings a wealth of science within reach. one way to achieve a cross-wavelength analysis is via `stacking', i.e. combining precise positional information from an image at one wavelength with data from one at another wavelength in order to extract source-flux distributions and other ... | fully-bayesian stacking in the presence of confusion |
for the past dozen years, the university of north carolina (unc) at chapel hill has been developing a unique, survey-level astronomy curriculum, primarily for undergraduate students, with the goal of significantly boosting stem enrollments on a national scale, as well as boosting students' technical and research skills... | robotic telescope labs for survey-level undergraduates |
faraday tomography is a new method of the study of cosmic magnetic fields enabled by broad-band low-frequency radio observations. using faraday tomography it is possible to obtain the faraday dispersion function, which contains information on the line-of-sight distributions of magnetic fields, thermal electron density,... | introduction to faraday tomography and its future prospects |
radio frequency interference (rfi) of impulsive nature is created by sources like sparking on high-power transmission lines due to gap or corona discharge and automobile sparking, and it affects the entire observing frequency bands of low-frequency radio telescopes. such rfi is a significant problem at the upgraded gia... | real-time rfi filtering for ugmrt: overview of the released system and relevance to the ska |
compact, massive star-forming galaxies at z ∼ 2.5 are thought to be building the central regions of giant elliptical galaxies today. however, a significant fraction of these objects were previously shown to have much smaller hα line widths than expected. a possible interpretation is that hα emission from their central ... | anomalously narrow line widths of compact massive star-forming galaxies at z ∼ 2.3: a possible inclination bias in the size-mass plane |
with the advent of modern astronomy, humans might now have acquired the technological and intellectual requirements to communicate with other intelligent beings beyond the solar system, if they exist. radio signals have been identified as a means for interstellar communication about 60 years ago. and the square kilomet... | decryption of messages from extraterrestrial intelligence using the power of social media - the seti decrypt challenge |
rotating radio transients (rrats) are sporadically emitting pulsars detectable only through searches for single pulses. while over 100 rrats have been detected, only a small fraction (roughly 20%) have phase-connected timing solutions, which are critical for determining how they relate to other neutron star populations... | wavelet denoising of radio observations of rotating radio transients (rrats): improved timing parameters for eight rrats |
current and upcoming radio-interferometers are expected to produce volumes of data of increasing size that need to be processed in order to generate the corresponding sky brightness distributions through imaging. this represents an outstanding computational challenge, especially when large fields of view and/or high-re... | high performance w-stacking for imaging radio astronomy data: a parallel and accelerated solution |
we present the results of 3 ghz radio continuum observations of 23 superluminous supernovae (slsne) and their host galaxies by using the karl g. jansky very large array conducted 5-21 yr after the explosions. the sample consists of 15 type i and 8 type ii slsne at z < 0.3, providing one of the largest samples of sls... | a vla survey of late-time radio emission from superluminous supernovae and the host galaxies |
we investigate the kinematic properties of galactic h ii regions using radio recombination line (rrl) emission detected by the australia telescope compact array at 4-10 ghz and the jansky very large array at 8-10 ghz. our h ii region sample consists of 425 independent observations of 374 nebulae that are relatively wel... | discovery of a new population of galactic h ii regions with ionized gas velocity gradients |
thanks to the first mm studies on the territory of the former ussr in the early 1960s and succeeding sub-mm measurements in the 1970s - early 1980s at wavelengths up to 0.34 mm, a completely unique astroclimate was revealed in the eastern pamirs, only slightly inferior to the available conditions on the chajnantor plat... | on the benefits of the eastern pamirs for sub-mm astronomy |
we present a formalism to extract the h i power spectrum from the epoch of reionization for drift scans using radio interferometers. our main aim is to determine the coherence timescale of time-ordered visibilities. we compute the two-point correlation function of the h i visibilities measured at different times to add... | detecting the 21 cm signal from the epoch of reionization using drift scans: correlation of time-ordered visibilities |
how do active galactic nuclei with low optical luminosities produce powerful radio emission? recent studies of active galactic nuclei with moderate radio and low optical luminosities (fanaroff & riley class i, fr i) searching for broad nuclear emission lines in polarized light, as predicted by some active galactic ... | searching for nuclear obscuration in the infrared spectra of nearby fr i radio galaxies |
in order to enhance the imaging capabilities of the event horizon telescope (eht) and capture the first black hole movies, the next-generation eht (ngeht) team is building new stations. most stations of the eht and ngeht project are located in the western hemisphere, leaving a large vacancy in the eastern hemisphere. l... | evaluation of a candidate site in the tibetan plateau towards the next generation event horizon telescope |
ultra fast astronomy is a new frontier becoming enabled by improved detector technology allowing discovery of optical transients on millisecond to nanosecond time scales. these may reveal counterparts of energetic processes such as fast radio bursts, gamma ray bursts, gravitational wave events, or play a role in the op... | ultra fast astronomy: optimized detection of multimessenger transients |
several recent investigations indicate the existence of gender-related systematic trends in the peer review of proposals for observations on astronomical facilities. this includes the national radio astronomy observatory (nrao) where there is evidence of a gender imbalance in the rank of proposals with male principal i... | gender systematics in the nrao proposal review system |
foreground mitigation is critical to all next-generation radio interferometers that target cosmology using the redshifted neutral hydrogen 21 cm emission line. attempts to remove this foreground emission have led to new analysis techniques as well as new developments in hardware specifically dedicated to instrument bea... | a digital calibration source for 21 cm cosmology telescopes |
interplanetary scintillation (ips) provides an approach for identifying the presence of subarcsec structures in radio sources, and very long baseline interferometry (vlbi) technique can help verify whether the ips sources have fine structures on milliarcsec scales. we searched the available vlbi archive for the 244 ips... | very long baseline interferometry properties of compact interplanetary scintillators detected by the murchison widefield array |
we present a methodology for automated real-time analysis of a radio image data stream with the goal to find transient sources. contrary to previous works, the transients we are interested in occur on a time-scale where dispersion starts to play a role, so we must search a higher-dimensional data space and yet work fas... | detecting dispersed radio transients in real time using convolutional neural networks |
electromagnetic radiation from human activities, known as man-made radio frequency interference (rfi), adversely affects radio astronomy observations. in the vicinity of the upgraded giant metrewave radio telescope (ugmrt) array, the sparking on power lines is the major cause of interference at observing frequencies le... | performance analysis techniques for real-time broadband rfi filtering system of ugmrt |
context. the square kilometer array (ska) is expected to detect high-redshift galaxies with star formation rates (sfrs) up to two orders of magnitude lower than herschel surveys and will thus boost the ability of radio astronomy to study extragalactic sources. the tight infrared-radio correlation offers the possibility... | infrared-radio relation in the local universe |
we present a bayesian analysis of data from the fields instrument on board the parker solar probe (psp) spacecraft with the aim of constraining low-frequency (≲6 mhz) sky in preparation for several upcoming lunar-based experiments. we utilize data recorded during psp's coning roll maneuvers, in which the axis of the sp... | constraining a model of the radio sky below 6 mhz using the parker solar probe/fields instrument in preparation for upcoming lunar-based experiments |
context. apertif is a multi-beam receiver system for the westerbork synthesis radio telescope that operates at 1.1-1.5 ghz, which overlaps with various radio services, resulting in contamination of astronomical signals with radio-frequency interference (rfi).aims: we analyse approaches to mitigate apertif interference ... | an interference detection strategy for apertif based on aoflagger 3 |
the origin and evolution of structure in the universe could be studied in the dark ages. the highly redshifted h i signal between 30 < z < 80 is the only observable signal from this era. human radio interference and ionospheric effects limit earth-based radio astronomy to frequencies >30 mhz. to observe the lo... | lunar far-side radio arrays: a preliminary site survey |
radio wavelengths are the longest discussed in this book, and therefore have the lowest energy. the very largest radio telescopes that astronomers have constructed collect barely enough energy to power a single light bulb. despite this, radio observations give us insight into some of the most energetic phenomena in the... | long-wave (radio) astronomy with coherent detection from radio to thz |
we present the results of forecasting flare activity based on the data from microwave spectropolarimetric observations of active regions (ars) obtained with the ratan-600 radio telescope and the x-ray data from the goes satellite as well as monitoring data. the method is designed for short-term (1-3-days) flare forecas... | a method of forecasting solar activity based on radio astronomical observations |
as part our investigation into the galactic rotation curve, we carried out very long baseline interferometry (vlbi) observations towards the star-forming region iras 01123+6430 using vlbi exploration of radio astrometry (vera) to measure its annual parallax and proper motion. the annual parallax was measured to be 0.15... | outer rotation curve of the galaxy with vera. iv. astrometry of iras 01123+6430 and the possibility of cloud-cloud collision |
the five-hundred-meter aperture spherical radio telescope (fast) will be fully commissioned later in 2019. once commissioned, operation and maintenance of fast will be the most prominent task. the unique working mode of active shape-changing of fast cable-net structure makes the traditional maintenance way, which combi... | prognostics and health management of fast cable-net structure based on digital twin technology |
as a part of china's chang'e-4 lunar far side mission, two lunar microsatellites for low frequency radio astronomy, amateur radio and education, longjiang-1 and longjiang-2, were launched as secondary payloads on 20 may 2018 together with the queqiao l2 relay satellite. on 25 may 2018, longjiang-2 successfully inserted... | design and flight results of the vhf/uhf communication system of longjiang lunar microsatellites |
an ever increasing amount of molecular material is being discovered in the interstellar medium, associated with the birth and death of stars and planetary systems. radio and millimeter-wave astronomical observations, made possible by high-resolution laboratory spectroscopy, uniquely trace the history of gas-phase molec... | prebiotic chemical evolution in the astrophysical context |
the results of observations of the quasar j0530+1331 (b0528+134) with the radio telescopes ratan-600 at frequencies of 4.6, 8.2, 11.2, 21.7 ghz and rt-32 at the zelenchukskaya and badary observatories of the quasar network of the institute of applied astronomy, the russian academy of sciences, at frequencies of 4.84 an... | short variability of the radio flux density from the blazar j0530+1331 |
the superconducting superconductor-insulator-superconductor (sis) receivers have become the preferred method for (sub)millimeter-wave radio astronomical observations due to the extremely low receiver noise temperature. the coupling noise of the local oscillator (lo) system is also a part of the receiver noise. in many ... | investigation on lo coupled noise in sideband separation superconducting sis receiver |
an investigation into type ii solar radio bursts was carried out to understand the frequency gap between fundamental and harmonic emissions of the radio burst. this investigation focused on type ii solar radio bursts with flares and coronal mass ejections by relating the separation between fundamental and harmonic emis... | investigation into cme shock speed resulting from type ii solar radio bursts |
extra-galactic x-ray research with the launch of xmm-newton has become the forefront of x-ray astronomy. x-ray sources outside our galaxy are the other galaxies - normal galaxies, radio galaxies, quasars, blazars, seyfert galaxies, as well as extended sources in galaxy clusters - the glow of cluster's halo. x-ray space... | extragalactic x-ray discrete sources |
the emerging generation of radio interferometric (ri) telescopes, such as the square kilometre array (ska), will acquire massive volumes of data and transition radio astronomy to a big-data era. the ill-posed inverse problem of imaging the raw visibilities acquired by ri telescopes will become significantly more comput... | online radio interferometric imaging: assimilating and discarding visibilities on arrival |
to improve the time and frequency reference standards used for radio astronomy and high precision atomic physics applications, we describe a novel stable frequency transmission technique. the approach uses a vertical-cavity surface- emitting laser (vcsel) based phase correction actuator. using a frequency mixing proces... | transmission of precise phase coherent optical signals using a vcsel stabilization system |
art and science so often inspire each other because they share a common denominator; the quest to understand and express deeper meaning in the universe. art and science explore the same space, attempting to explain, comprehend, and provide perspective to the universe encountered. giant step is an interdisciplinary site... | giant step: the heartbeat and words of neil armstrong returned to the moon |
pulsar research has been a hot topic in the area of astronomy since they were first discovered. pulsar discovery is fundamental for pulsar research. while pulsars are now visible across the electromagnetic spectrum, pulsar searches with modern radio telescopes are most promising. as the performance of astronomical inst... | pulsar-candidate selection using a generative adversarial network and resnext |
context. sulfur-containing molecules constitute only 8% of the molecules observed in the interstellar medium (ism), in spite of the fact that sulfur has been shown to be an abundant element in the ism. in order to understand the chemical behavior of the ism and specific cases like the missing sulfur reservoir, a detail... | the millimeter-wave spectrum and astronomical search for ethyl methyl sulfide |
the young core-collapse supernova sn 2022acko (=dlt22v/atlas22bnms/ztf22abyivoq; tns astronomical transient report no. 166420) in ngc 1300, classified as a type iip event, has been observed with the australia telescope compact array (atca) at 5.5 and 9.0 ghz on 08 dec 2022 10:20-13:05 ut. no radio emission was detected... | radio observations of sn 2022acko |
"fully polarimetric" in its original radio science usage denotes a receiving instrument's ability to measure the four-parameter stokes vector characterizing the polarimetric properties of an electro-magnetic (em) field. in contrast, radar remote sensing specialists use "fully polarimetric" to apply exclusively to radar... | polarimetric portraits |
as a technical demonstration of an astronomical receiver working in a frequency range of 275-500 ghz, we are developing such a wide-band one, called as band 7 + 8 receiver. the splined corrugated horn and corresponding quasi-optics in the receiver designed for aste telescope in chile are described. the fabricated horn ... | design and characterization of 275-500 ghz corrugated horns and optics for a wideband radio astronomy receiver |
the square kilometre array (ska) ushers in the new generation of large radio telescopes that will work at wavelengths between meters and centimeters. in order to competitively design interferometric antenna arrays such as ska, it is crucial to focus on the optimization of system performance. in this paper, we contribut... | optimization of positioning of interferometric array antennas using division algorithm for radio astronomy applications |
we have developed, manufactured, and tested a waveguide mixer in the range 211-275 ghz on the basis of the superconductor-insulator-superconductor (sis) tunnel structures. the methods of manufacturing high-quality tunnel structures on quartz substrates have been worked out. to extend the receiver band, the nb/alox/nb a... | low-noise sis receivers for new radio-astronomy projects |
we have undertaken a detailed investigation, based on the available evidence, of the sequence of events that led to the historical discovery of the first quasar, 3c 273. | the sequence of events that led to the 1963 publications in nature of 3c 273, the first quasar and the first extragalactic radio jet |
using λ21 cm galactic neutral hydrogen data from the hi4pi survey and 0.75-30 mev γ-ray emission from the imaging compton telescope, we have searched for the origin event that accelerated high-velocity cloud complex m. radio plots of l - b, l - v, and b - v show a cavity centered at (l, b) ~ (150°, 50.°) and extending ... | radio and γ-ray evidence for the supernova origin of high-velocity cloud complex m |
the trans-coronal radio array fleet (t-craf) is a mission concept designed to continuously probe the magnetic field and plasma density structure of the corona at heliocentric distances of ~2-10rsun (solar radius,rsun=695,700km). t-craf consists of thirty small satellites orbiting the sun-earth lagrange point l3 in orde... | multipoint radio probe of the solar corona: the trans-coronal radio array fleet (t-craf) |
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