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we revisit the exquisite archival radio data for the type ic supernova sn 1994i and present a revised model for the supernova (sn) radio emission and a pilot study that aims to constrain the rate of c-band radio transients within the face-on host galaxy, m51 (ngc 5194). we find that the temporal and spectral evolution ... | a new model for the radio emission from sn 1994i and an associated search for radio transients in m51 |
the five-component profile of the 2.7 ms pulsar j0337+1715 appears to exhibit the best example to date of a core/double-cone emission-beam structure in a millisecond pulsar (msp). moreover, three other msps, the binary pulsars b1913+16, b1953+29, and j1022+1001, seem to exhibit core/single-cone profiles. these configur... | toward an empirical theory of pulsar emission. xii. exploring the physical conditions in millisecond pulsar emission regions |
the lack of short baselines, referred to as the short-spacing problem (ssp), is a well-known limitation of the performance of radio interferometers, causing a reduction of the flux detected from source structure on large angular scales. the very large number of antennas operated in the atacama large millimeter/sub-mill... | alma observations of w hydrae: impact of missing baselines |
we study the morpho-kinematics of the circumbinary envelope of mira ceti between ∼100 and ∼350 au from the stars using alma observations of the sio (ν = 0, j= 5-4) and co (ν = 0, j = 3-2) emissions with the aim of presenting an accurate and reliable picture of what cannot be ignored when modelling the dynamics at stake... | revealing new features of the millimetre emission of the circumbinary envelope of mira ceti |
the modulation of the intensity of microwave emission from a plasma slab caused by a standing linear kink fast magnetoacoustic wave is considered. the slab is stretched along a straight magnetic field, and can represent, for example, a current sheet in a flaring active region in corona of the sun, or a streamer or pseu... | microwave response to kink oscillations of a plasma slab |
the narrow line seyfert 1 galaxy iras17020+4544 is one of the few active galactic nuclei (agns) where a galaxy-scale energy-conserving outflow was revealed. this paper reports on noema observations addressed to constrain the spatial scale of the co emission in outflow. the molecular outflowing gas is resolved in five c... | noema spatially resolved view of the multiphase outflow in iras17020+4544: a shocked wind in action? |
we present a multiwavelength study of the extended green object, g12.42+0.50, in this paper. the associated ionized, dust, and molecular components of this source are studied in detail employing various observations at near-, mid- and far-infrared, submillimetre, and radio wavelengths. radio continuum emission mapped a... | initial phases of high-mass star formation: a multiwavelength study towards the extended green object g12.42+0.50 |
the electromagnetic power that comes from the sun has been proved to be an effective reference for checking the quality of dual-polarization weather radar receiver. operational monitoring methods have been developed and implemented for determining the electromagnetic antenna pointing, assessing the receiver stability, ... | calibration accuracy of the dual-polarization receivers of the c-band swiss weather radar network |
we report results for a complete sample of 10 luminous radio-quiet quasars with large c iv equivalent widths (ew ≥ 150 å). for 8/10 we performed chandra snapshot observations. we find that, in addition to the enhanced c iv line ew, their he ii and mg ii lines are enhanced, but the c iii] line is not. their x-ray emissi... | the nature of luminous quasars with very large c iv equivalent widths |
we present detailed 3d modeling of a dense, coronal thick-target x-ray flare using the gx simulator tool, photospheric magnetic measurements, and microwave imaging and spectroscopy data. the developed model offers a remarkable agreement between the synthesized and observed spectra and images in both x-ray and microwave... | validation of the coronal thick target source model |
we investigated the star formation activities in the afgl 333 region, which is in the vicinity of the w 4 expanding bubble, by conducting nh3 (1,1), (2,2), and (3,3) mapping observations with the 45 m nobeyama radio telescope an angular resolution of 75″. the morphology of the nh3 (1,1) map shows a bow-shaped structure... | interaction between the h ii region and afgl 333-ridge: implications for the star formation scenario |
solar 10.7-cm radio flux (f10.7) is an important measure of solar radio emission activity. accurate f10.7 forecasting plays a key role in both space weather and global environment forecasts. we discover that forecasting errors are heteroscedastic, something that is not often considered in previous models. in addition, ... | linear multistep f10.7 forecasting based on task correlation and heteroscedasticity |
context. among the intermediate-mass magnetic chemically peculiar (mcp) stars, cu vir is one of the most intriguing objects. its 100% circularly polarized beams of radio emission sweep the earth as the star rotates, thereby making this strongly magnetic star the prototype of a class of nondegenerate stellar radio pulsa... | outstanding x-ray emission from the stellar radio pulsar cu virginis |
understanding non-thermal particle generation, transport, and escape in solar flares requires detailed quantification of the particle evolution in the realistic 3d domain where the flare takes place. rather surprisingly, apart from the standard flare scenario and integral characteristics of non-thermal electrons, not m... | revealing the evolution of non-thermal electrons in solar flares using 3d modeling |
we have carried out a long-term infrared and x-ray investigation of the colliding-wind binary wr 125 (wc7 + o9iii). the source was monitored using astrosat soft x-ray telescope and the tata institute of fundamental research near infrared imaging camera-ii mounted at the back of 3.6 m devasthal optical telescope. wr 125... | quest for the upcoming periastron passage of an episodic dust maker and particle-accelerating colliding-wind binary: wr 125 |
we present an observational study of the vibrationally excited h2o line at 658 ghz ({ν }2 = 1, {1}{1,0}-1{}{0,1}) toward orion kl using the atacama large millimeter/submillimeter array (alma). this line is clearly detected at the position of the massive protostar candidate, source i. the spatial structure is compact, w... | alma observation of the 658 ghz vibrationally excited h2o maser in orion kl source i |
radio polarization measurements of pulsed emission from pulsars offer a valuable insight into the basic geometry of the neutron star: inclination angle between the magnetic and rotation axis and inclination of the line of sight. so far, all studies about radio polarization focused on the standard rotating vector model ... | polarized emission from an off-centred dipole |
m87 hosts a 3-6 billion solar mass black hole with a remarkable relativistic jet that has been regularly monitored in radio to tev bands. however, hard x-ray emission ≳10 kev, which would be expected to primarily come from the jet or the accretion flow, had never been detected from its unresolved x-ray core. we report ... | hard x-ray emission from the m87 agn detected with nustar |
on 25 october 2012 the reuven ramaty high energy solar spectroscope imager (rhessi) and the tropical rainfall measuring mission (trmm) satellites passed over a thunderstorm on the coast of sri lanka. rhessi observed a terrestrial gamma ray flash (tgf) originating from this thunderstorm. optical measurements of the caus... | on the timing between terrestrial gamma ray flashes, radio atmospherics, and optical lightning emission |
a spinning neutron star (ns) that is asymmetric with respect to its spin axis can emit continuous gravitational wave (gw) signals. the spin frequencies and their distribution of radio millisecond pulsars (msps) and accreting msps provide some evidences of gw radiation, and msps are ideal probes detecting high frequency... | constraining the ellipticity of millisecond pulsars with observed spin-down rates |
we present karl g. jansky very large array k-band (19 ghz) observations of the redshifted co(1-0) line emission toward the radio galaxy tn j0924-2201 at z = 5.2, which is one of the most distant radio galaxies with co detected. with an angular resolution of ~2″, the co(1-0) line emission is resolved into three clumps, ... | massive molecular gas companions uncovered by very large array co(1-0) observations of the z = 5.2 radio galaxy tn j0924-2201 |
solar flares are driven by the release of free magnetic energy and its conversion to other forms of energy-kinetic, thermal, and nonthermal. quantification of partitions between these energy components and their evolution is needed to understand the solar flare phenomenon including nonthermal particle acceleration, tra... | data-constrained 3d modeling of a solar flare evolution: acceleration, transport, heating, and energy budget |
hubble space telescope (hst) images obtained in 2018 are combined with archival hst data taken in 1995 to detect changes and measure proper motions in the hh 80/81 shock complex, which is powered by the fastest known jet driven by a forming star, the massive object iras 18162-2048. some persistent features close to the... | hh 80/81: structure and kinematics of the fastest protostellar outflow |
neutron stars accreting from ob supergiants are often divided between persistently and transiently accreting systems, called supergiant x-ray binaries (sgxbs) and supergiant fast x-ray transients (sfxts). this dichotomy in accretion behaviour is typically attributed to systematic differences in the massive stellar wind... | the first mm detection of a neutron star high-mass x-ray binary |
to understand the formation and growth of supermassive black holes (smbhs) and their coevolution with host galaxies, it is essential to know the impact of environment on the activity of active galactic nuclei (agns). we present new chandra x-ray observations of nuclear emission from member galaxies in the antlia cluste... | amuse-antlia. i. nuclear x-ray properties of early-type galaxies in a dynamically young galaxy cluster |
we report new vla and e-merlin high-resolution and -sensitivity images of the triple radio continuum source in the serpens star-forming region. these observations allowed us to perform a deep multifrequency, multiepoch study by exploring the innermost regions (≲100 au) of an intermediate-mass young stellar object for t... | resolving the collimation zone of an intermediate-mass protostellar jet |
we present magnetohydrodynamic (mhd) simulations of the magnetic interactions between a solar-type star and short-period hot jupiter exoplanets using the publicly available mhd code pluto. it has been predicted that emission due to magnetic interactions such as the electron cyclotron maser instability (ecmi) will be ob... | interacting fields and flows: magnetic hot jupiters |
variable oh/ir stars are asymptotic giant branch (agb) stars with an optically thick circumstellar envelope that emit strong oh 1612 mhz emission. they are commonly observed throughout the galaxy but also in the lmc and smc. hence, the precise inference of the distances of these stars will ultimately result in better c... | distances of stars by mean of the phase-lag method |
context. massive stars and their stellar winds are important for a number of feedback processes. the mass lost in the stellar wind can help determine the end-point of the star as a neutron star (ns) or a black hole (bh). however, the impact of mass loss on the post-main sequence evolutionary stage of massive stars is n... | a radio census of the massive stellar cluster westerlund 1 |
context. the sightline to w31c g10.62-0.38 was extensively observed in absorption under the prismas program on herschel.aims: we relate absorbing material to the older view of galactic molecules gained from co emission.methods: we used the arizona radio observatory kitt peak 12m antenna to observe emission from the j =... | molecular gas in absorption and emission along the line of sight to w31c g10.62-0.38 |
we report the results of the 12co (j = 3-2) and hco+ (j = 4-3) observations of the w40 h ii region with the atacama submillimeter telescope experiment (aste) 10 m telescope (hpbw ≃ 22″) to search for molecular outflows and dense clumps. we found that the velocity field in the region is highly complex, consisting of at ... | dense clumps and candidates for molecular outflows in w40 |
the sub-thz event observed on the 4 july 2012 with the bauman moscow state technical university radio telescope rt-7.5 at 93 and 140 ghz as well as kislovodsk and metsähovi radio telescopes, radio solar telescope network (rstn), goes, rhessi, and sdo orbital stations is analyzed. the spectral flux between 93 and 140 gh... | on the origin of 140 ghz emission from the 4 july 2012 solar flare |
context. ab doradus is the main system of the ab doradus moving group. it is a quadruple system formed by two widely separated binaries of pre-main-sequence (pms) stars: ab dor a/c and ab dor ba/bb. the pair ab dor a/c has been extensively studied and its dynamical masses have been determined with high precision, thus ... | dynamical masses of the low-mass stellar binary ab doradus b |
we performed a multi-wavelength study toward h ii region sh2-104. new maps of 12co j = 1 - 0 and 13co j = 1 - 0 were obtained from the purple mountain observatory 13.7 m radio telescope. sh2-104 displays a double-ring structure. the outer ring with a radius of 4.4 pc is dominated by 12, 500 μm, 12co j = 1 - 0, and 13co... | two-dimensional molecular gas and ongoing star formation around h ii region sh2-104 |
the dynamics of colliding-wind binary (cwb) systems and conditions for efficient particle acceleration therein have attracted multiple numerical studies in recent years. these numerical models seek an explanation of the thermal and nonthermal emission of these systems as seen by observations. in the nonthermal regime, ... | colliding-wind binaries with strong magnetic fields |
context. colliding winds in massive binaries are able to accelerate particles up to relativistic speeds as the result of the interaction between the winds of the different stellar components. hd 167971 exhibits this phenomenon which makes it a strong radio source.aims: we aim at characterizing the morphology of the rad... | a vlbi study of the wind-wind collision region in the massive multiple hd 167971 |
magnetars are conjectured to be highly magnetized neutron stars (nss). strong internal magnetic field and elasticity in the crust may deform the stars and lead to free precession. we study the precession dynamics of triaxially deformed nss incorporating the near-field and the far-field electromagnetic torques. we obtai... | precession of magnetars: dynamical evolutions and modulations on polarized electromagnetic waves |
colliding-wind binaries (cwbs) constitute an emerging class of γ-ray sources powered by strong, dense winds in massive stellar systems. the most powerful of them are those binaries hosting a wolf-rayet (wr) star. following the recent discovery of apep - the closest known galactic wr-wr binary - we discuss the non-detec... | limits on the non-thermal emission of the wr-wr system apep |
protostellar jets and outflows are pointers of star-formation and serve as important sources of momentum and energy transfer to the interstellar medium. radio emission from ionized jets have been detected towards a number of protostellar objects. in few cases, negative spectral indices and polarized emission have also ... | radio spectra of protostellar jets: thermal and non-thermal emission |
in recent decades our understanding of solar active regions (ars) has improved substantially due to observations made with better angular resolution and wider spectral coverage. while prior ar observations have shown that these structures were always brighter than the quiet sun at centimeter wavelengths, recent observa... | a genetic algorithm to model solar radio active regions from 3d magnetic field extrapolations |
we investigate the kinematics of high-mass protostellar objects within the high-mass star-forming region iras 19410+2336. we performed high angular resolution observations of 6.7-ghz methanol and 22 ghz water masers using the multi-element radio linked interferometer network (merlin) and e-merlin interferometers. the 6... | methanol and water maser observations separate disc and outflow sources in iras 19410+2336 |
this paper describes the design and performance of the search coil magnetometers (scm), which are part of the plasma wave investigation (pwi) instrument onboard the bepicolombo/mio spacecraft (mercury magnetospheric orbiter), which will measure the electric field, plasma waves and radio waves for the first time in merc... | measurements of magnetic field fluctuations for plasma wave investigation by the search coil magnetometers (scm) onboard bepicolombo mio (mercury magnetospheric orbiter) |
the search for exoplanets in the radio bands has been focused on detecting radio emissions produced by the interaction between magnetized planets and the stellar wind (auroral emission). here we introduce a new tool, which is part of our mhd stellar corona model, to predict the ambient coronal radio emission and its mo... | exoplanet modulation of stellar coronal radio emission |
this paper demonstrates the importance of having near-real-time low corona cme observations, 0.05 to 0.4 nm solar flare emission, low frequency radio emissions, relativistic electron intensities from l4, and high-quality energetic proton measurements from the sel line and l4. the availability of these data in near-real... | observations for improving sep forecasts and warnings |
characteristics of changes in the solar activity indices (the flux of the solar radio emission at a wavelength of 10.7 cm f and the new version of the relative sunspot number ri) and the ionospheric index of this activity t in the 23rd and 24th solar cycles, which were low by the amplitude of solar and geomagnetic acti... | solar activity indices for ionospheric parameters in the 23rd and 24th cycles |
structured particle precipitation in the cusp is an important source for the generation of f region ionospheric irregularities. the equatorward boundaries of broad doppler spectral width in super dual auroral radar network (superdarn) data and the concurrent oi 630.0 nm auroral emission are good empirical proxies for t... | f region ionosphere effects on the mapping accuracy of superdarn hf radar echoes |
the observed values of the rate of change of the orbital and the spin periods of pulsars are affected by different dynamical effects, for example, the line-of-sight acceleration and the proper motion of the pulsar relative to the sun. we explore these dynamical effects thoroughly and point out the drawbacks of popular ... | dynamical effects in the observed rate of change of the orbital and the spin periods of radio pulsars: improvement in the method of estimation and its implications |
there is accumulating evidence that at least a fraction of binary neutron star (bns) mergers result in rapidly spinning magnetars, with subrelativistic neutron-rich ejecta as massive as a small fraction of a solar mass. the ejecta could be heated continuously by the poynting flux emanated from the central magnetars. su... | reverse shock emission and ionization breakout powered by post-merger millisecond magnetars |
the hh80-81 system is one of the most powerful jets driven by a massive protostar. we present new near-infrared (nir) line imaging observations of the hh80-81 jet in the h2 (2.122 μm) and [fe ii] (1.644 μm) lines. these lines trace not only the jet close to the exciting source but also the knots located farther away. w... | imaging of hh80-81 jet in the near-infrared shock tracers h2 and [fe ii] |
we calculate the expected effects on the spectral energy distributions and light curves in x-ray binary jets from eclipses by the donor stars. jets will be eclipsed for all inclination angles, with just the height along the jet where the eclipse takes place being set by the orbital parameters. typically, eclipses will ... | eclipses of jets and discs of x-ray binaries as a powerful tool for understanding jet physics and binary parameters |
we report our high-resolution (0.03 arcsec-0.07 arcsec) atacama large millimeter/submillimeter array (alma) imaging of the quadruply lensed radio-loud quasar mg j0414+0534 at redshift z = 2.639 in the continuum and the broad co(11-10) line at ∼340 ghz. with the help of strong lensing magnification and alma's high resol... | alma 50-parsec-resolution imaging of jet-ism interaction in the lensed quasar mg j0414+0534 |
we present new effelsberg 100-m, australia telescope compact array (atca), and very large array observations of rotational sis transitions in the circumstellar envelope (cse) of irc +10216. thanks to the high angular resolution achieved by the atca observations, we unambiguously confirm that the molecule’s j=1\to 0 tra... | sis in the circumstellar envelope of irc +10216: maser and quasi-thermal emission |
previously, nova puppis 1991 (v351 pup) was measured to host one of the most massive ejections claimed in the literature. multi-frequency radio detections from one epoch were published for this nova in the 1990's; and yet, the remaining data collected by the karl g. jansky very large array (vla) have remained unpublish... | a radio emission analysis of classical nova v351 pup (1991) |
current models of titan's ionosphere have difficulties in explaining the observed electron density and/or temperature. in order to get new insights, we re-analyzed the data taken in the ionosphere of titan by the cassini langmuir probe (lp), part of the radio and plasma wave science (rpws) instrument. this is the first... | re-analysis of the cassini rpws/lp data in titan's ionosphere: 1. detection of several electron populations |
we have performed an unbiased dense core survey toward the orion a giant molecular cloud in the c18o (j = 1-0) emission line taken with the nobeyama radio observatory (nro) 45 m telescope. the effective angular resolution of the map is 26″, which corresponds to ~0.05 pc at a distance of 414 pc. by using the herschel-pl... | the c18o core mass function toward orion a: single-dish observations |
we present a detailed analysis of a cool-core galaxy cluster abell 3017, at a redshift of z = 0.219, which has been identified to be merging with its companion cluster abell 3016. this study has made use of x-ray (chandra), ultraviolet (uv) [galaxy evolution explorer(galex)], optical [european southern observatory (eso... | a detailed study of x-ray cavities in the intracluster environment of the cool core cluster abell 3017 |
we present results obtained from alma co (2-1) data of the double-barred galaxy ngc 3504. with three times higher angular resolution (~0${_{.}^{\prime\prime}}$8) than previous studies, our observations reveal an inner molecular gas bar, a nuclear ring, and four inner spiral arm-like structures in the central 1-kpc regi... | morphological and kinematical analysis of the double-barred galaxy ngc 3504 using alma co (2-1) data |
protoplanetary disks emit radiation across a broad range of wavelengths, requiring a multiwavelength approach to fully understand their physical mechanisms and how they form planets. observations at submillimeter to centimeter wavelengths can provide insights into the thermal emission from dust, free-free emission from... | radio multiwavelength analysis of the compact disk cx tau: presence of strong free-free variability or anomalous microwave emission |
the low-mass star gj 1151 has been reported to display variable low-frequency radio emission, which has been interpreted as a signpost of coronal star-planet interactions with an unseen exoplanet. here we report the first x-ray detection of gj 1151's corona based on the xmm-newton data. we find that the star displays a... | the corona of gj 1151 in the context of star-planet interaction |
we present a multiwavelength study of the galactic luminous blue variable hr carinae, based on new high-resolution mid-infrared (ir) and radio images obtained with the very large telescope (vlt) and the australia telescope compact array (atca), which have been complemented by far-infrared herschel-photodetector array c... | exploring the multifaceted circumstellar environment of the luminous blue variable hr carinae |
i investigate the possibility that a recently reported radio transient in m81, vtc j095517.5 + 690813, was caused by the accretion-induced collapse of a white dwarf. it became bright in the radio, but no associated optical transient was discovered. an accretion-induced collapse is predicted to be radio-bright but optic... | vtc j095517.5 + 690813: a radio transient from the accretion-induced collapse of a white dwarf? |
using 3 years (2013-2015) of o2(0-1) and oh(6-2) band nightglow emission intensities and corresponding rotational temperatures as tracers of mesospheric dynamics, we have investigated large- and small-timescale variations in the mesosphere over a low-latitude location, gurushikhar, mount abu (24.6° n, 72.8° e), in indi... | large- and small-scale periodicities in the mesosphere as obtained from variations in o2 and oh nightglow emissions |
agroecosystems compose large economic sectors in dominantly agriculture-based societies. availability and management of water resources have a huge influence on the sustainability of agroecosystems. low soil moisture is a major constraint on crop growth due to its vital role in providing crops with sufficient nutrition... | a uas-based rf testbed for water utilization in agroecosystems |
we report on two millimeter flares detected by alma at 220 ghz from au mic, a nearby m dwarf. the larger flare had a duration of only $\sim35$ sec, with peak $l_{r}=2\times10^{15}$ erg s$^{-1}$ hz$^{-1}$, and lower limit on linear polarization of $|q/i|>0.12\pm0.04$. we examine the characteristics common to these ne... | properties of m dwarf flares at millimeter wavelengths |
the hypothesis of two phases of charged particle acceleration in solar flares is well known, with subrelativistic electrons accelerated in the first phase and relativistic electrons and protons in the second. both phases are distinguished in the solar proton events and their parent flares of december 26, 2001 (m7.1), n... | two phases of solar flares and a stochastic mechanism for acceleration of electrons and protons |
we present very large array observations at 33.0 ghz that detect emission coincident with ɛ eridani to within 0.″07 (0.2 au at the distance of this star), with a positional accuracy of 0.″05. this result strongly supports the suggestion of previous authors that the quiescent centimeter emission comes from the star and ... | flat-spectrum radio continuum emission associated with ɛ eridani |
we report the results of subparsec-scale submillimeter observations toward an embedded high-mass young stellar object in the small magellanic cloud (smc) with alma. complementary infrared data obtained with the akari satellite and the gemini south telescope are also presented. the target infrared point source is spatia... | a multiline study of a high-mass young stellar object in the small magellanic cloud with alma: the detection of methanol gas at 0.2 solar metallicity |
the karl jansky very large array (vla), owens valley radio observatory (ovro), atacama large millimetric array (alma), and the infrared spitzer observatories are powerful facilities to study massive star formation regions and related objects such as ultra-compact (uc) h ii regions, molecular clumps, and cores. we used ... | ultracompact h ii regions with extended emission: the case of g43.89-0.78 and its molecular environment |
we present sensitive (rms-noises ∼4-25 μjy) and high angular resolution (∼1″-2″) 8.9 ghz (3.3 cm) karl g. jansky very large array radio continuum observations of 10 presumed transitional disks associated with young low-mass stars. we report the detection of radio continuum emission in 5 out of the 10 objects (rxj1615, ... | 3.3 cm jvla observations of transitional disks: searching for centimeter pebbles |
energetic electrons with power-law spectra are commonly observed in astrophysics. this paper investigates electron cyclotron maser emission (ecme) from the power-law electrons, in which strong pitch-angle anisotropy is emphasized. the electron distribution function proposed in this paper can describe various types of p... | cyclotron maser emission from power-law electrons with strong pitch-angle anisotropy |
we present karl g. jansky very large array 1.3, 3.6, and 6 cm continuum maps of compact radio sources in the orion nebular cluster (onc). we mosaicked 34 arcmin2 at 1.3 cm, 70 arcmin2 at 3.6 cm and 109 arcmin2 at 6 cm, containing 778 near-infrared detected young stellar objects and 190 hubble space telescope-identified... | a vla survey for faint compact radio sources in the orion nebula cluster |
we provide new observations of the lmc x-1 o star and its extended nebula structure using spectroscopic data from vlt/uves as well as hα imaging from the wide field imager on the max planck gesellschaft/european southern observatory 2.2 m telescope and atca imaging of the 2.1 ghz radio continuum. this nebula is one of ... | lmc x-1: a new spectral analysis of the o-star in the binary and surrounding nebula |
previous radio and infrared observations have revealed an obscured region of high-mass star formation in cygnus known as onsala 2 (on2). within this region lies the optically revealed young stellar cluster berkeley 87, which contains several ob stars and the rare oxygen-type wolf-rayet star wr 142. previous radio studi... | chandra observations of the massive star-forming region onsala 2 |
we present the results from a series of ground-based radio observations toward a planck galactic cold clump (pgcc), pgcc g108.84-00.81, which is located in one curved filamentary cloud in the vicinity of an extended h ii region sh2-152 and snr g109.1-1.0. pgcc g108.84-00.81 is mainly composed of two clumps, “g108-n” an... | star formation conditions in a planck galactic cold clump, g108.84-00.81 |
this paper presents the multiwavelength analysis of a 13 s quasi-periodic pulsation (qpp) observed in hard x-ray (12-300 kev) and microwave (4.9-34 ghz) emissions during a c-class flare that occurred on 2015 september 21. atmospheric image assembly (aia) 304 and 171 å images show an emerging loop/flux tube (l1) moving ... | observation of a short period quasi-periodic pulsation in solar x-ray, microwave, and euv emissions |
ae aqr was until recently the only known magnetic cataclysmic variable (mcv) containing a rapidly spinning (33.08 s) white dwarf (wd). its radio emission is believed to be a superposition of synchrotron-emitting plasmoids, because it has a positive spectral index spanning three orders of magnitude (≈2-2000 ghz) and is ... | vla observations of the ae aqr-type cataclysmic variable lamost j024048.51+195226.9 |
flare-associated quasiperiodic pulsations (qpps) in radio and x-ray wavelengths, particularly those related to nonthermal electrons, contain important information about the energy release and transport processes during flares. however, the paucity of spatially resolved observations of such qpps with a fast time cadence... | multiple regions of nonthermal quasiperiodic pulsations during the impulsive phase of a solar flare |
the pulsed radio emission of rotating neutron stars is connected to slow tearing instabilities feeding off an inhomogeneous twist profile within the open circuit. this paper considers the stability of a weakly sheared, quantizing magnetic field in which the current is supported by a relativistic particle flow. the elec... | radio emission of pulsars. i. slow tearing of a quantizing magnetic field |
we present the analysis of the onset of the new 2010s oh flaring event detected in the oh ground-state main line at 1665 mhz towards o ceti and compare its characteristics with those of the 1990s' flaring event. this is based on a series of complementary single-dish and interferometric observations both in oh and h2o o... | recurring oh flares towards o ceti - i. location and structure of the 1990s' and 2010s' events |
so far, the sun is the only isolated main-sequence star detected in gamma-rays, particularly during powerful flares. young ultracool dwarfs are far more active so they are also plausible gamma-ray sources. we performed a spatial stack of 97 of the nearest x-ray and radio flare stars to search for gev emission using nea... | a stacking search for gamma-ray emission from nearby flare stars and the periodic source tvlm 513-46546 |
the silicon heterojunction (shj) solar cell has long been considered as one of the most promising candidates for the next-generation pv market. transition metal oxides (tmos) show good carrier selectivity when combined with c-si solar cells. this has led to the rapid demonstration of the remarkable potential of tmos (e... | sub-stochiometric moo xby radio-frequency magnetron sputtering as hole-selective passivating contacts for silicon heterojunction solar cells |
almost three billion people rely on biomass stoves for their basic domestic needs such as cooking, heating and lighting, leading to indoor air pollution (iap) and health risks. thermoelectric generators collect wasted heat from biomass stoves and convert it to electricity to power a fan that pushes air into the chamber... | development of stove-powered thermoelectric generators: a review |
a three-dimensional, multifluid simulation of a giant planet’s magnetospheric interaction with steady-state stellar wind from a sun-like star was performed for four different orbital semimajor axes—10, 5, 1, and 0.2 au. we simulate the effect of the increasing, steady-state stellar wind pressure related to the planetar... | extrasolar giant magnetospheric response to steady-state stellar wind pressure at 10, 5, 1, and 0.2 au |
nowadays, indoor positioning (ip) is a relevant aspect in several scenarios within the internet of things (iot) framework, e.g., industry 4.0, smart city and smart factory, in order to track, amongst others, the position of vehicles, people or goods. this paper presents the realization and testing of a low power sensor... | self-sufficient sensor node embedding 2d visible light positioning through a solar cell module |
we report the detection of outflowing molecular gas in the center of the nearby (z=0.014) massive radio galaxy ngc6328. the radio core of the galaxy, pks b1718-649, is identified as a gigahertz peaked spectrum source with a compact (2 pc) double radio lobe morphology. we used alma co(2-1) and co(3-2) observations at 10... | co kinematics unveil outflows plausibly driven by a young jet in the gigahertz peaked radio core of ngc 6328 |
we studied the evolution of five active regions (ars) where strong x-class flares occurred in 2011 - 2012 (noaa ars 11158, 11166, 11263, 11283 and 11520). our study focuses on the pre-flare phase of these ars (during a few days before the flare) to reveal features in the microwave radiation and magnetic-field character... | dynamics of microwave sources associated with the neutral line and the magnetic-field parameters of sunspots as a factor in predicting large flares |
the wind imaging interferometer (windii) empirical model, which provides the characteristics of the o(1d) 630.0 nm atomic oxygen dayglow emission from the upper atmosphere has been reviewed and updated. it now includes the integrated emission rate, the peak volume emission rate, the altitude of that peak and the full w... | on the relationship of the o(1d) 630.0 nm dayglow emission to the f10.7 cm solar flux and the solar zenith angle |
the long-term temperature changes of the mesopause region at the hydroxyl molecule oh (6-2) nighttime height and its connection with the geomagnetic activity during the 23rd and beginning of the 24th solar cycles are presented. measurements were conducted with an infrared digital spectrograph at the maimaga station (63... | influence of geomagnetic activity on mesopause temperature over yakutia |
context. the presence and properties of compact radio sources embedded in massive star forming regions can reveal important physical properties about these regions and the processes occurring within them. the ngc 6334 complex, a massive star forming region, has been studied extensively. nevertheless, none of these stud... | richness of compact radio sources in ngc 6334d to f |
we report the discovery of new, high-velocity narrow-line components of the oh megamaser in iras 20100-4156. results from the australian square kilometre array pathfinder (askap)'s boolardy engineering test array (beta) and the australia telescope compact array (atca) provide two independent measurements of the oh mega... | high-velocity oh megamasers in iras 20100-4156: evidence for a supermassive black hole |
all possible types of interaction of a magnetized plasma flow with an obstacle (magnetized or not) are considered, and those susceptible to produce a radio signature are identified. the role of the sub-alfvénic or super-alfvénic character of the flow is discussed. known examples in the solar system are given, as well a... | star-planet interactions in the radio domain: prospect for their detection |
we studied the polarized spectrum of the post-agb binary system 89 herculis on the basis of data collected with the high-resolution catania astrophysical observatory spectropolarimeter, harps-north polarimeter and echelle spectropolarimetric device for the observation of stars. we find the existence of linear polarizat... | the solar-like `second spectrum' and polarized metal lines in the emission of the post-agb binary 89 herculis |
we performed a multi-wavelength observation toward the lkhα 101 embedded cluster and its adjacent 85'×60' region. the lkhα 101 embedded cluster is the first and only significant cluster in the california molecular cloud (cmc). these observations have revealed that the lkhα 101 embedded cluster is located just at the pr... | first embedded cluster formation in california molecular cloud |
v959 mon (nova mon 2012) was first detected by the fermi large area telescope in june 2012, as a transient gamma-ray source. subsequent optical observations showed that this gamma-ray emission was due to a classical nova explosion. multifrequency observations of v959 mon with the very large array (vla) between 2012 jun... | multi-epoch radio imaging of γ-ray nova v959 mon |
we have studied the pulse-to-pulse variability in psr j1820-0427 and its frequency dependence using high-quality, wide-band observations made with the upgraded giant metrewave radio telescope (ugmrt; 300-750 mhz) and the murchison widefield array (~170-200 mhz). the low-frequency data reveal a previously unreported fea... | single-pulse analysis and average emission characteristics of psr j1820-0427 from observations made with the mwa and ugmrt |
when a planet transits in front of its host star, a fraction of its light is blocked, decreasing the observed flux from the star. the same is expected to occur when observing the stellar radio flux. however, at radio wavelengths, the planet also radiates, depending on its temperature, and thus modifies the transit dept... | planetary transits at radio wavelengths: secondary eclipses of hot jupiter extended atmospheres |
we present the discovery and timing solutions of four millisecond pulsars (msps) discovered in the arecibo 327 mhz drift-scan pulsar survey. three of these pulsars are in binary systems, consisting of a redback (psr j2055+1545), a black widow (psr j1630+3550), and a neutron star-white dwarf binary (psr j2116+1345). the... | discovery and timing of millisecond pulsars with the arecibo 327 mhz drift-scan survey |
mwc 297 is a young, early-type star driving an ionized outflow and surrounded by warm, entrained dust. previous analyses of near- and mid-ir interferometric images suggest that the emission at these wavelengths arises from a compact accretion disk with a moderate (i < 40°) inclination. we have obtained 5-40 μm image... | multiwavelength observations of mwc 297: constraints on disk inclination and mass outflow |
the authors analyze the process of stratospheric ozone layer destruction. the ozone layer is a protective biosphere shield. the authors identify and study the main causes of ozone sphere destruction having both natural and anthropogenic nature. the article explains a mechanism of the ozone layer depletion — this is cau... | ozone layer destruction and ways of its recovery |
in this paper we present the results of a mid-infrared study of g49.5-0.4, or w51a, part of the massive starbirth complex w51. combining public data from the spitzer irac camera, and gemini mid-infrared camera t-recs at 7.73, 9.69, 12.33, and 24.56 μm, with a spatial resolution of ∼0.″5, we have identified the mid-infr... | a mid-infrared view of the high mass star formation region w51a |
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