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context. some radio pulsar profiles (in particular those of millisecond pulsars) contain wide emission structures which cover large intervals of pulse phase. local distortions of an average curve of polarisation angle (pa) can be identified in such profiles, and they are often found to be associated with absorption fea... | a model for distortions of polarisation-angle curves in radio pulsars |
we report the results of ongoing monitoring of the 6.7 ghz ch3oh masers associated with g188.95+0.89. in these observations, five features are periodically varying and at least two exhibit evidence of velocity drifts. it is not clear the cause of these velocity drifts. the spectra have varied significantly since detect... | massive protocluster of a periodic maser source g188.95+0.89 |
the origin of 3he abundance enhancements in gradual solar energetic particle (sep) events remains largely unexplained. two mechanisms have been suggested: the reacceleration of remnant flare material by coronal mass ejection (cme)-driven shocks in interplanetary space, and concomitant activity in the corona. we explore... | the first gradual solar energetic particle event with an enhanced 3he abundance on solar orbiter |
we investigate dust-unbiased star formation rates (sfrs) as a function of the environment in 20 massive clusters ($m_{200}\gt 4\times 10^{14}\, {\rm m}_{\odot }$) between 0.15 < $z$ < 0.35 using radio luminosities (l1.4ghz) from the recently released meerkat galaxy cluster legacy survey catalogue. we use optical ... | the meerkat galaxy clusters legacy survey: star formation in massive clusters at 0.15 < z < 0.35 |
we report i-band photometric observations of the radio-detected m9.5 dwarf bri 0021-0214, obtained with the galway ultra fast imager on the 1.8 m vatican advanced technology telescope (vatt) at mt. graham international observatory, arizona. in total, 19 h of observations over a 73 d baseline were obtained. bri 0021-021... | optical variabiphase dispersion minimizationlity, rotation period, and inclination angle of the m9.5 dwarf bri 0021-0214 |
we have developed a new method of data processing for radio telescope observation data to measure time-dependent temporal coherence, and we have named it "cross-correlation spectrometry" (xcs). xcs is an autocorrelation procedure that expands time lags over the integration time and is applied to data obtained from a si... | development of cross-correlation spectrometry and the coherent structures of maser sources |
in the past two decades, it has been convincingly argued that magnetospheric radio emissions, of cyclotron maser origin, can occur for exoplanetary systems, similarly as solar planets, with the same periodicity as the planetary orbit. these emissions are primarily expected at low frequencies (usually below 100 mhz, c.f... | palantir: an updated prediction tool for exoplanetary radio emissions |
we present near-ir photometry and spectroscopy of 30 extremely luminous radio and mid-ir-selected galaxies. with bolometric luminosities exceeding ~1013 $\rm {l_{\odot }}$ and redshifts ranging from z = 0.880 to 2.853, we use very large telescope instruments x-shooter and infrared spectrometer and array camera to inves... | the black hole masses of extremely luminous radio-wise selected galaxies |
we analyze the emission line profiles detected in deep optical spectra of quasars to derive the mass of their super-massive black holes (smbh) following the single-epoch virial method. our sample consists in six radio-loud (rl) quasars and four radio-quiet (rq) quasars. we carefully fit a broad and narrow gaussian comp... | quasar host galaxies and the msmbh-σ* relation |
the massive binary system formed by η car and an unknown companion is a strong source at millimetre and submillimetre wavelengths. close to the stars, continuum bremsstrahlung and radio recombination lines originate in the massive ionized wind of η car and in several compact sources of high density plasma. molecular li... | telluric absorption lines in the alma spectra of η car |
we present alma and atca observations of the luminous blue variable rmc 127. the radio maps show for the first time the core of the nebula and evidence that the nebula is strongly asymmetric with a z-pattern shape. hints of this morphology are also visible in the archival hubble space telescope {{h}}α image, which over... | the luminous blue variable rmc 127 as seen with alma and atca |
we present results of 12co(j = 2-1) observations toward four massive star-forming galaxies at z ∼ 1.4 with the nobeyama 45 m radio telescope. the galaxies are detected with spitzer/mips in 24 μm and herschel/spire in 250 μm and 350 μm, and they mostly reside in the main sequence. their gas-phase metallicities derived b... | gas-to-dust ratios in massive star-forming galaxies at z ∼ 1.4 |
we present detections of the co(4-3) and [c i] 609 μm spectral lines, as well as the dust continuum at 480.5 ghz (rest frame), in 3c 368, a fanaroff-riley class ii (fr-ii) galaxy at redshift (z) 1.131. 3c 368 has a large stellar mass, ∼ 3.6 × 1011 m ⊙, and is undergoing an episode of vigorous star formation, at a rate ... | co and fine-structure lines reveal low metallicity in a stellar-mass-rich galaxy at z ∼ 1? |
we analysed specific regions of reduced soft x-ray and microwave emission in five large isolated sunspots. the nobeyama radioheliograph 17 ghz observations reveal a local depression of microwave brightness in the peripheral area of the sunspots. the depression regions appear light (weak absorption) in the he 10830 å li... | reduced coronal emission above large isolated sunspots |
conductive adhesives (cas) providing reliable connections between electronic components, have been widely used in solar cells [1], light emitting diodes (leds) [2], radio frequency components [3], and printed & wearable circuits, etc. [4-6]. basically, cas are mainly composed of conductive fillers and resin, which ... | a flexible adhesive with a conductivity of 5240 s/cm |
we present a chandra and xmm-newton study of the supernova remnant (snr) ctb 37b, along with archival radio observations. in radio wavelengths, the snr ctb 37b is an incomplete shell showing bright emission from the eastern side, while the x-ray morphology shows diffuse emission from regions surrounding the magnetar cx... | x-ray and radio studies of snr ctb 37b hosting the magnetar cxou j171405.7-381031 |
we obtained radio observations of the symbiotic binary and known recurrent nova t coronae borealis following a period of increased activity in the optical and x-ray bands. a comparison of our observations with those made prior to 2015 indicates that the system is in a state of higher emission in the radio as well. the ... | t crb: radio observations during the 2016-2017 “super-active” state |
we present h i 21 cm emission observations of the z ∼ 0.006 32 subdamped lyman-α absorber (sub-dla) towards pg 1216+069 made using the arecibo telescope and the very large array (vla). the arecibo h i 21cm spectrum corresponds to an h i mass of ∼3.2 × 107 m⊙, two orders of magnitude smaller than that of a typical spira... | h i 21cm emission from the subdamped lyman-α absorber at z = 0.0063 towards pg 1216+069 |
the ska will be a state of the art radiotelescope optimized for both large area surveys as well as for deep pointed observations. in this paper we analyze the impact that the ska will have on galactic studies, starting from the immense legacy value of the all-sky survey proposed by the continuum swg but also presenting... | the impact of ska on galactic radioastronomy: continuum observations |
we present very large array 7 mm continuum observations of four ultracompact (uc) hii regions, observed previously at 1.3 cm, in order to investigate the nature of the compact radio sources associated with these regions. we detect a total of seven compact radio sources, four of them with thermal emission, and two compa... | exploring the nature of compact radio sources associated to uchii regions |
aims: we aim to study the spatial distribution of the physical and chemical properties of the x-ray emitting plasma of the supernova remnant (snr) g306.3-0.9 in detail to obtain constraints on its ionization stage, the progenitor supernova explosion, and the age of the remnant.methods: we used combined data from xmm-ne... | detailed study of snr g306.3-0.9 using xmm-newton and chandra observations |
we present a multi-wavelength observational study of a low-mass star-forming region, l1251-c, with observational results at wavelengths from the near-infrared to the millimeter. spitzer space telescope observations confirmed that iras 22343+7501 is a small group of protostellar objects. the extended emission in the eas... | infrared and radio observations of a small group of protostellar objects in the molecular core, l1251-c |
we have detected sporadic, bright, short-duration radio pulses from psr j0901-4624. these pulses are emitted simultaneously with persistent, periodic emission that dominates the flux density when averaging over many periods of the pulsar. the bright pulses have energies that are consistent with a power-law distribution... | two radio-emission mechanisms in psr j0901-4624 |
origin of magnetic fields, its structure and effects on dynamical processes in stars to galaxies are not well understood. lack of a direct probe has remained a problem for its study. the first phase of square kilometre array (ska-i), will have almost an order of magnitude higher sensitivity than the best existing radio... | probing magnetic fields with square kilometre array and its precursors |
a combination of archival multifrequency radio observations with narrow-band h α optical imagery and new confirmatory optical spectroscopy have shown that candidate supernova remnant (snr) g6.31+0.54 can now be confirmed as part of a galactic snr. it has non-thermal emission, an optical emission line spectrum displayin... | confirmation of g6.31+0.54 as a part of a galactic supernova remnant |
we report the detection of thermal continuum radio emission from the k0 iii coronal giant pollux (β gem) with the karl g. jansky very large array (vla). the star was detected at 21 and 9 ghz with flux density values of 150 ± 21 and 43 ± 8 μjy, respectively. we also place a 3σrms upper limit of 23 μjy for the flux densi... | detection of thermal radio emission from a single coronal giant |
we searched for thermal gyro-synchrotron radio emission from a sample of five radio-loud stars whose x-ray coronae contain a hot ($t_e\gt 10^7\,$k) thermal component. we used the jvla to measure stokes i and v/i spectral energy distributions (seds) over the frequency range 15 - 45 ghz, determining the best-fitting mode... | a search for thermal gyro-synchrotron emission from hot stellar coronae |
this paper analyses the effects of solar radio emissions in the radiomobile context, for the first time leveraging massive european telecommunications standards institute (etsi) 3rd generation partnership program (3gpp) minimization of drive test (mdt) radio measures produced by 4g lte (long term evolution) terminals a... | solar radio emission as a disturbance of radiomobile networks |
iras 12272-6240 is a complex star-forming region with a compact massive dense clump (dc) and several associated masers, located at a well-determined distance of d = 9.3 kpc from the sun. for this study, we obtained sub-arcsec broad- and narrow-band near-infrared (near-ir) imaging and low-resolution spectroscopy with th... | an infrared study of the high-mass, multistage star-forming region iras 12272-6240 |
recent discoveries of higher harmonic cyclotron emissions in aurora occurring under daylight conditions motivated the modification of radio receivers at south pole station, antarctica, to measure fine structure of such emissions during two consecutive austral summers, 2013-2014 and 2014-2015. the experiment recorded 34... | comparison of fine structures of electron cyclotron harmonic emissions in aurora |
wolf-rayet (wr) stars are evolved massive stars, presumably on their way to becoming supernovae. they are characterized by high luminosities and fast and dense stellar winds. we have detected signs of a radio continuum pinwheel associated with wr 147, a nitrogen-rich wr star with spectral subtype wn8. these structures ... | a radio pinwheel emanating from wr 147 |
we present high-angular resolution observations of oh maser emission towards the high-mass star-forming region iras 06056+2131. the observations were carried out using the uk radio interferometer array, multi-element radio linked interferometer network (merlin) in the oh main lines at 1665 and 1667 mhz, in addition to ... | oh maser towards iras 06056+2131: polarization parameters and evolution status |
lspm j1314+1320 (=nltt 33370) is a binary star system consisting of two nearly identical pre-main-sequence stars of spectral type m7. the system is remarkable among ultracool dwarfs for being the most luminous radio emitter over the widest frequency range. masses and luminosities are at first sight consistent with the ... | lspm j1314+1320: an oversized magnetic star with constraints on the radio emission mechanism |
psr b1821-24 is a solitary millisecond pulsar that radiates multi-wavelength pulsed photons. it has complex radio, x-ray, and γ-ray pulse profiles with distinct peak phase separations that challenge the traditional caustic emission models. using the single-pole annular gap model with a suitable magnetic inclination ang... | modeling multi-wavelength pulse profiles of the millisecond pulsar psr b1821-24 |
debris disks are usually thought to be gas-poor, the gas being dissipated by accretion or evaporation during the protoplanetary phase. hd141569a is a 5 myr old star harboring a famous debris disk, with multiple rings and spiral features. i present here the first pdbi maps of the 12co(2-1), 13co(2-1) gas and dust emissi... | hd141569a: disk dissipation caught in action |
the next generation very large array will have excellent sensitivity for detecting the thermal emission from massive stars and from red giants. this will allow direct imaging of the winds for a large number of hot massive stars. it will also allow using the radio emission for the massive stars as a way to detect stars ... | massive and evolved stars with the ngvla |
for electron acceleration during solar flares, it is very important to determine the pitch-angle and energy dependences of the electron distribution function. at present, this cannot be done directly from observations. therefore, it is necessary to perform a numerical simulation of the propagation of accelerated electr... | modeling of physical processes by analysis of hard x-ray and microwave radiations in the solar flare of november 10, 2002 |
in this paper the anomalous intense pulse of psr j0953+0755 was studied in the decametre wavelength range. for this pulse, two scales of fine structure were discovered. the long-scale structure consists of four components, where the visible dispersion measures of even and odd components are different. the obtained time... | detection of the fine structure of the pulsar j0953+0755 radio emission in the decametre wave range |
we study quasi-periodic pulsations (qpps) during the impulsive phase of the c8.3 flare sol2002-08-06t01:43. the shape of an extended 5.7 ghz source is similar to a tadpole with the head located above the region of a negative magnetic polarity, surrounded by positive polarity patches and with a remote tail source. the f... | double peak quasi-periodic pulsations in a circular-ribbon flare |
the miniature x-ray solar spectrometer (minxss-1) cubesat observed solar x-rays between 0.5 and 10 kev. a two-temperature, two-emission-measure model is fit to each daily averaged spectrum. these daily average temperatures and emission measures are plotted against the corresponding daily solar 10.7 cm radio flux (f10.7... | modeling the daily variations of the coronal x-ray spectral irradiance with two temperatures and two emission measures |
analyzing the solar radio spectra in the 0.8-4.5 ghz frequency range observed at the ondřejov observatory during 2000-2015 we found 118 drifting pulsating structures (dpss). among them we found 8 dpss with distinct quasi-periodic oscillations in frequency. periods of these oscillations are in the range of 4-75 s. based... | frequency oscillations of drifting pulsating structures |
during non-flaring times, the radio flux of the sun at wavelengths of a few centimeters to several tens of centimeters mostly originates from thermal bremsstrahlung emission, very similar to extremeultraviolet (euv) radiation. owing to such a proximity, it is feasible to investigate the relationship between the euv emi... | synthesising solar radio images from atmospheric imaging assembly extreme-ultraviolet data |
based on an analysis of data from the midlatitude ionospheric stations, it is found that the p = 0.5(f1 + f81) index is an optimal solar-activity index for the daily values of the e-layer critical frequency foe, where f1 and f81 are the solar radio-emission flux at a wavelength of 10.7 cm on the given day and the value... | solar-activity index for the e-layer critical frequency at middle latitudes |
the solar radiation affects the life on earth and it is important in meteorology, climatology, solar energy, agriculture, hydrology and seismology, too. the sun warms the earth which reflects a part of the energy. an effect of tectonic stress increases the ground temperature that is radiated into the atmosphere. we stu... | evaluation of the solar radiation in a seismic zone |
we present an analysis of high angular resolution observations made in the x-ray and the radio with the chandra x-ray observatory and the karl jansky very large array (vla), respectively, of the nearby spiral galaxy ngc 45. this galaxy is the third that we have considered in a study of the supernova remnant (snr) popul... | chandra and very large array observations of the nearby sd galaxy ngc 45 |
this paper is aimed to investigate the mutual relationship between ozone-density at cold-point mesopause (o3-cpm) and solar activity globally using sounding of the atmosphere using broadband emission radiometry (saber) measurements and the 10.7 cm-solar-radio-flux (f10.7) data set. for this purpose, the global latitude... | the responses of ozone density to solar activity in the mesopause region and the mutual relationship based on saber measurements during 2002-2016 |
radiative feedback from massive stars can potentially trigger star formation in the surrounding molecular gas. inspired by the case of radiatively driven implosion in m16 or eagle nebula, we analyse a similar case of star formation observed in the cygnus x region. we present new james clerk maxwell telescope observatio... | a case study of triggered star formation in cygnus x |
the close active binary hr 5110 was observed at six epochs over 26 days using a global very long baseline interferometry array at 15.4 ghz. we used phase referencing to determine the position of the radio centroid at each epoch with an uncertainty significantly smaller than the component separation. after correcting fo... | radio astrometry of the close active binary hr5110 |
ionization potential is an important parameter for the design of semiconductor devices. since amorphous semiconductors do not have long-range ordering and lattice constants, it is not necessary to consider lattice defects at interfaces. if the ionization potential can be controlled with such an amorphous semiconductor,... | tuning of ionization potential in amorphous cd-in-o thin films |
all too often, maxwell's equations are taught as mathematical abstractions without any connections to students' personal experiences. however, the interaction of radio waves with earth's ionosphere provides an opportunity to apply maxwell's equations in scenarios that have some connections to students' daily lives. a d... | electromagnetic mirrors in the sky: accessible applications of maxwell's equations |
microwave observations of the solar active region noaa 11734 were done on april 28-may 8, 2013 with ssrt and the ratan-600 radio telescopes. as a result of observations, two-dimensional distributions of the stokes parameters i and v were obtained according to data from the ssrt at a frequency of 5.7 ghz and a microwave... | observations and modeling of the spatial distribution and microwave radiation spectrum of the active region noaa 11734 |
we present a high-resolution, near-ir spectroscopic study of multiple outflows in the lkhα 234 star formation region using the immersion grating infrared spectrometer (igrins). spectral mapping over the blueshifted emission of hh 167 allowed us to distinguish at least three separate, spatially overlapped outflows in h2... | high-resolution near-ir spectral mapping with h2 and [fe ii] lines of multiple outflows around lkhα 234 |
using visible, radio, microwave, and submillimeter data, we study several lines of sight toward stars generally closer than 1 kpc on a component-by-component basis. we derive the component structure seen in absorption at visible wavelengths from ca ii, ca i, k i, ch, ch+, and cn and compare it to emission from h i, co ... | the connection between different tracers of the diffuse interstellar medium: kinematics |
context. impulsive radio and hard x-ray emission from large solar flares are usually attributed to a hard distribution of high-energy electrons accelerated in the energy dissipation process of magnetic reconnection.aims: we report the detection of impulsive radio and hard x-ray emissions produced by a population of ene... | impulsive radio and hard x-ray emission from an m-class flare |
the high kinetic energy electrons that populate the earth's radiation belts emit synchrotron emissions because of their interaction with the planetary magnetic field. a lunar near side array would be uniquely positioned to image this emission and provide a near real time measure of how the earth's radiation belts are r... | measuring the earth's synchrotron emission from radiation belts with a lunar near side radio array |
we describe the algorithm, implementation, and numerical tests of a multifluid dust module in the athena++ magnetohydrodynamic code. the module can accommodate an arbitrary number of dust species interacting with the gas via aerodynamic drag (characterized by the stopping time), with a number of numerical solvers. in p... | a multifluid dust module in athena++: algorithms and numerical tests |
exoplanets around different types of stars provide a window into the diverse environments in which planets form. this chapter describes the observed relations between exoplanet populations and stellar properties and how they connect to planet formation in protoplanetary disks. giant planets occur more frequently around... | planet populations as a function of stellar properties |
recent theoretical works suggest that the pebble accretion process is important for planet formation in protoplanetary discs, because it accelerates the growth of planetary cores. while several observations reveal axisymmetric sharp gaps in very young discs, which may be indicative of the existence of planets. we inves... | pebble accretion in class 0/i ysos as a possible pathway for early planet formation |
in laboratory experiments, we study the motion of levitated, sedimenting clouds of submillimeter grains at low ambient pressure and at high solid-to-gas ratios ɛ. the experiments show a collective behavior of particles, i.e., grains in clouds settle faster than an isolated grain. in collective particle clouds, the sedi... | laboratory experiments on the motion of dense dust clouds in protoplanetary disks |
we present simulations of the capabilities of the atacama large millimeter/submillimeter array (alma) and of a next-generation very large array (ngvla) to detect and resolve substructures due to terrestrial planets and super-earths in nearby planet-forming disks. we adopt the results of global 2d hydrodynamical planet-... | imaging the dusty substructures due to terrestrial planets in planet-forming disks with alma and the next-generation very large array |
this paper constructs an analytic description for the late stages of giant planet formation. during this phase of evolution, the planet gains the majority of its final mass through gas accretion at a rapid rate. this work determines the density and velocity fields for material falling onto the central planet and its ci... | analytic approach to the late stages of giant planet formation |
the panels above show 10 x 14 images of dust emission from the disk that surrounds the young star pds 70, captured with the atacama large millimeter/submillimeter array (alma). see that purple blob of emission on the inside-right of the disk in the center panel? according to a new study led by andrea isella (rice unive... | featured image: a disk for a newly born planet |
this alma image of the protoplanetary disk surrounding the star hl tauri reveals the detailed substructure of the disk, including gaps that may have been cleared by planets. [alma (eso/naoj/nrao)]the gas giant pds 70b made headlines last month as the first newly forming planet to ever be directly imaged. now a team of ... | planet formation caught in the act |
in this paper, i present results of four protoplanetary disks, studied by our team, that show signs of planet formation. our high angular resolution radio interferometric observations of these sources suggest that we are witnessing different stages of the planet formation and disk evolution processes working at differe... | signs of planet formation in protoplanetary disks |
planets begin their lives shrouded in mystery, embedded in the swirling disks of gas and dust that surround newly born stars. as we try to understand the physical processes at play in these obscured environments, one stands out as a particular unknown: turbulence. new observations have now given us a look at the presen... | turbulent beginnings for future planets? |
in the early stages of planet formation in a protoplanetary disk the first coalescing bodies are weakly bound. conditions in the disk, such as the presence of gas (drag), make further growth through centimeter and meter sized bodies difficult. for centimeter-sized aggregates self-gravity is almost non-existent and elec... | collision experiments between centimeter-sized protoplanetesimals in microgravity |
debris disks probe a critical evolutionary link between the era of planet formation in protoplanetary disks and the mature planetary systems unveiled by exoplanet surveys. the dust in debris disks exhibits structural features that are linked to the presence of currently unobservable planets, while the gas component has... | gas and dust in debris disks |
our solar system hosts no planets with masses between earth and uranus, yet such planets abound throughout the galaxy. many of these low-mass exoplanets are also low-density, requiring gas-rich envelopes to explain their large sizes. we propose to use wfc3/ir to observe transmission spectra for two planets at the extre... | the atmospheres of two low-mass, low-density exoplanets transiting a young star |
the disk surrounding the star im lupi has come into clearer focus in the past few years thanks to new observations that revealed spirals, kinks, and other interesting structures. could a hidden planet be the cause of all these features?a detailed diskim lupi as seen at a wavelength of 1.25 mm. the white bar in the lowe... | evidence for a hidden planet in im lupi's disk |
the building blocks of planets in planet-forming ("protoplanetary") disks are assembled early in the lifetime of a young star. the gas disks are relatively short-lived, with a half-life of about 3 million years, as chemical reactions modify the reservoir of material from the natal molecular cloud. 5 - 7.5 μm wavelength... | infrared spectroscopic studies of water and organics in protoplanetary disks around young stars |
we propose to test the following hypothesis: the gas-giant exoplanet wasp-107b is unusually inflated, and methane-depleted, because it is young, and therefore has a high internal temperature. if this is correct, the temperature throughout its atmosphere should be high enough for sodium and potassium to be in the gas ph... | how hot is the inside of a young planet? |
the building blocks of planets in planet-forming ("protoplanetary") disks are assembled early in the lifetime of a young star. the gas disks are relatively short-lived, with a half-life of about 3 million years, as chemical reactions modify the reservoir of material from the natal molecular cloud. spitzer space telesco... | infrared spectroscopic studies of gases in the circumstellar environments of young stellar objects |
astrobites reports on an extra protoplanet that might be lurking in the dust around a nearby star. | a potential new character in the saga of hd 163296 |
most planetary system only offer the possibility to measure the initial conditions of planet formation (e.g., protoplanetary disks) separately from the final outcome (e.g., planet demographics of field samples). planet-hosting binaries offer the rare opportunity to observe both simultaneously. for example, in our previ... | orbital architectures of planet-hosting binaries: testing co-alignment |
>modern astronomy observations have discovered fascinating features that cannot be easily explained. consequently, researchers frequently develop models that eventually explain the observed phenomenon. this paper reviews the essential aspects of the quasi-keplerian theory of accretion around magnetized objects. star... | basic elements of the quasi-keplerian theory of accretion |
the formation of stars often leads to the formation of compact gas-dust disks near them. the viscosity of the gas leads over time to the expansion of these disks and the formation of dust on their cold periphery. two possible scenarios of the evolution of such disks over time, describing the formation of planets in the... | formation of hot planets in the circumstellar gas-dust disk |
the discovery of multi-planet resonant chains such as those in trappist-1 and kepler-90, where adjacent planets are in different commensurabilities, has raised questions on the formation of these systems and the reason for the diversity of their resonances. it is widely accepted that these systems formed through the co... | size and resonance diversity of multi-planet resonant chains is a natural outcome of their formation |
what do we know about the detailed structures of protoplanetary disks, the disks of gas in dust in which planets are born? a lot more now, thanks to the disk substructures at high angular resolution project (dsharp) one of the first large programs conducted using the atacama large millimeter/submillimeter array (alma).... | featured image: detail in the birth environments of planets |
giant planets are thought to form in circumstellar disks surrounding young stars, but material may also accrete into a smaller disk around the planet. weve never detected one of these circumplanetary disks before but thanks to new simulations, we now have a better idea of what to look for.image from previous work simul... | exploring disks around planets |
this image, captured with the very large telescope sphere adaptive optics in chile, reveals the large-scale spiral arms visible in the mwc 758 protoplanetary disk, located less than 500 light-years away. such arms are thought to be triggered by one of two mechanisms: gravitational instability, or a companion orbiting w... | featured image: a search for spiral-arm-driving planets |
located a mere 176 light-years away, tw hydrae is an 8-million-year-old star surrounded by a nearly face-on disk of gas and dust. recent observations have confirmed the existence of a gap within that disk a particularly intriguing find, since gaps can sometimes signal the presence of a planet.gaps and planetsnumerical ... | a gap in tw hydrae's disk |
core-accretion theory predicts that the formation of giant planets predominantly occurs at the dense mid-plane of the inner ~50 au of protoplanetary disks. however, due to observational limitation, this critical region remains to be the least charted area in protoplanetary disks. with its great sensitivity, alma recent... | unveiling the mid-plane temperature and mass distribution in the giant-planet formation zone |
astrobites reports on the connection between hurricanes on earth and planet formation in protoplanetary disks. | the calm before the — planet formation? |
the architecture of observed exoplanet systems is tailored by planet formation in protoplanetary disks and by the star-planet interactions making planet orbit on secular timescales. previous statistical studies using nasa's kepler mission have revealed a dearth of close-in planets around fast rotating stars, but recent... | architecture of kepler single exoplanet systems (porb vs. prot) compared to star-planet evolution models (espem) |
astrobites reports on an investigation of a protoplanetary disk that might prove to be one of the youngest disks to exhibit gravitational instability. | young, cool, and on edge: an unstable protoplanetary disk |
astrobites reports on a new framework developed to use models and observations to pinpoint the likely location of an exoplanet's formation. | flipping the table: inferring planet formation from atmospheric composition |
the young star elias 2-27 is surrounded by a massive disk with spectacular spiral arms. a team of scientists from university of cambridges institute of astronomy has now examined what might cause this disks appearance.top: alma 1.3-mm observations of elias 2-27s spiral arms, processed with an unsharp masking filter. tw... | what shaped elias 2-27's disk? |
are baby planets responsible for the gaps and rings weve spotted in the disks that surround distant, young stars? a new study led by christophe pinte (monash university, australia; univ. grenoble alpes, france) has found evidence supporting this theory in the images of eight circumstellar disks observed in the disk sub... | featured image: evidence for planets in disks? |
its an old debate: gravity or companions? the spectacular spiral arms we see in some protoplanetary disks are likely caused by one or the other and a recent study has taken a speedy approach to figuring out which.whats driving patterns?among the many swirling disks of gas and dust weve spotted around young, newly forme... | checking the speed of spirals |
young stars are surrounded by rotating disks of gas and dust. these disks play an essential role in regulating the mass accretion onto the star and are the precursors of exoplanetary systems. accretion disks also play an important role in driving the bipolar collimated ejections (jets) that remove the excess of angular... | protoplanetary disks, jets, and the birth of the stars |
planet formation in a protoplanetary disk starts with the coagulation of micrometer-sized solid particles. it is widely accepted that planetary precursors formed from these agglomerates. comets are remnants from this era and their internal structure still gives evidence of their formation history. therefore, to underst... | a new experimental approach to studying co2-ice collisions |
planets form in protoplanetary disks. new instruments like alma and vlt / sphere are revealing features in young disks that may be the traces of these planets: rings, gaps, spirals. the direct detection of forming planets still located inside their disk remains, however, very challenging. the consequence is that direct... | observing the first phases of planet formation: measuring vertical dust settling in a sample of edge-on disks |
in this comic-book-style talk, i will take you along the adventures of protagonists spirou and fantasio as they explore the enigmatic tau boötis exoplanetary system. their quest? to study the atmosphere of this keystone hot jupiter and relate its inferred envelope composition back to our understanding of how giant plan... | where is the water? jupiter-like c/h ratio but strong h2o depletion found on tau boo b using spirou |
near- to far-infrared imaging and spectroscopy of nearby (<~100 pc), low mass pre-main sequence stars that are orbited by gaseous and dusty circumstellar disks allow astronomers to probe the chemical composition and structure of protoplanetary disks, and further understand disk evolution and planet formation process... | infrared investigations of the composition and structure of nearby protoplanetary disks |
in mystery thriller books, the authors always lead you to suspect that the culprit is someone outside the group: the gardener or the locksmith, perhaps. sometimes, however, the answer is right in front of you, and the perpetrator is in the inner circle. a group of astronomers hasrecently reached the same conclusion: th... | a new angle on forming misaligned stellar systems |
we present the first sub-arcsecond images of 49 ceti in the [c i] 3{p}1-3{p}0 emission and the 614 mu m dust continuum emission observed with the atacama large millimeter/submillimeter array (alma), as well as that in the co(j=3-2) emission prepared by using the alma archival data. this result supported the first detec... | [c i] observations toward 49 ceti with aste and alma. |
when and how planets form in protoplanetary disks is still a topic of discussion. exoplanet detection surveys and protoplanetary disk surveys are now providing results that allow us to have new insights. we collect the masses of confirmed exoplanets and compare their dependence with stellar mass with the same dependenc... | why do protoplanetary disks appear not massive enough to form the known exoplanet population? |
bright rings and dark gaps are common features in images of protoplanetary disks. how we interpret these features is key to our understanding of how planetary systems form and evolve so what do these rings and gaps really mean?alma image of continuum (dust) emission from hd 163296, the subject of todays paper. [alma (e... | the origin of gaps in protoplanetary disks |
ci tauri is thought to host a massive planet roughly five times closer than mercury is to the sun, but observations reveal ample radiation arising from gas and dust close to the star gas and dust that we would expect to be missing if a planet were present. can astronomers explain these conflicting observations?synthesi... | a young star's disk dilemma |
this alma image of the protoplanetary disk surrounding the star hl tauri reveals the detailed substructure of the disk, including gaps that may have been cleared by planets. [alma (eso/naoj/nrao)]the atacama large millimeter/submillimeter array (alma) has provided a decades worth of detailed views of cold gas and dust ... | mapping planet-forming disks with alma |
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