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we report on chandra x-ray observatory (cxo) observations of the pulsar wind nebula (pwn) associated with psr b0355+54 (eight observations with a 395 ks total exposure, performed over an eight month period). we investigated the spatial and spectral properties of the emission coincident with the pulsar, compact nebula (... | deep chandra observations of the pulsar wind nebula created by psr b0355+54 |
freely decaying, relativistic force-free turbulence is studied for the first time. we initiate the magnetic field at a short wavelength and simulate its relaxation toward equilibrium on two- and three-dimensional periodic domains in both helical and nonhelical settings. force-free turbulent relaxation is found to exhib... | freely decaying turbulence in force-free electrodynamics |
we report on the discovery of ionised gas filaments in the circum-galactic halo of the extremely metal-poor compact starburst sbs 0335-052e in a 1.5 h integration with the muse integral-field spectrograph. we detect these features in hα and [o iii] emission down to a limiting surface-brightness of 5 × 10-19 erg s-1 cm-... | vlt/muse illuminates possible channels for lyman continuum escape in the halo of sbs 0335-52e |
the mammoth-i nebula at redshift 2.3 is one of the largest known lyα nebulae in the universe, spanning ∼440 kpc. enormous lyα nebulae like mammoth-i typically trace the densest and most active regions of galaxy formation. using sensitive low-surface-brightness observations of co(1-0) with the very large array, we trace... | the cold circumgalactic environment of mammoth-i: dynamically cold gas in the core of an enormous lyα nebula |
aims: r coronae australis (r cra) is the brightest star of the coronet nebula of the corona australis (cra) star forming region. this star is very red in color, probably due to dust absorption, and is strongly variable. high-contrast instruments allow for an unprecedented direct exploration of the immediate circumstell... | exploring the r cra environment with sphere. discovery of a new stellar companion |
one observational prediction for type ia supernovae (sne ia) explosions produced through white dwarf-white dwarf collisions is the presence of bimodal velocity distributions for the 56ni decay products, although this signature can also be produced by an off-centre ignition in a delayed detonation explosion. these bimod... | signatures of bimodality in nebular phase type ia supernova spectra |
the nilsson et al. lyα nebula has often been cited as the most plausible example of an lyα nebula powered by gravitational cooling. in this paper, we bring together new data from the hubble space telescope and the herschel space observatory as well as comparisons to recent theoretical simulations in order to revisit th... | overturning the case for gravitational powering in the prototypical cooling lyα nebula |
a tremendous international effort is currently dedicated to observing the so-called primordial b modes of the cosmic microwave background (cmb) polarisation. if measured, this faint signal, caused by the primordial gravitational wave background, would be evidence of the inflation epoch and quantify its energy scale, pr... | absolute calibration of the polarisation angle for future cmb b-mode experiments from current and future measurements of the crab nebula |
recently, we have measured the ir absorptions of c60+, c60-, and c602+ in neon matrixes. many previously unknown absorptions were established. here we compare our laboratory ir absorption spectra for c60+ and c602+ to the ir emission spectra of several astronomical objects that show c60 emission. we find that ir bands ... | on observing c60+ and c602+ in laboratory and space |
as the chemical compositions of ci chondrites closely resemble that of the sun's photosphere, their oxygen isotopic compositions represent a powerful tool to constrain the origin and dynamics of dust and water ice grains in the protoplanetary disk. however, parent-body alteration processes make straightforward estimati... | primordial water and dust of the solar system: insights from in situ oxygen measurements of ci chondrites |
we propose a scenario where a companion that is about to exit a common-envelope evolution (cee) with a giant star accretes mass from the remaining envelope outside its deep orbit and launches jets that facilitate the removal of the remaining envelope. the jets that the accretion disc launches collide with the envelope ... | energizing the last phase of common-envelope removal |
we use the new non-local-thermodynamical-equilibrium (nlte) light curve and spectral synthesis code jekyll to evolve a macro-scopically mixed ejecta model of a type iib supernova (sn) originating from a star with an initial mass of 12 m⊙ through the photospheric and nebular phase. the ejecta model is adopted from earli... | spectral modelling of type iib supernovae. comparison with sn 2011dh and the effect of macroscopic mixing |
in unequilibrated chondrites, the ferromagnesian silicates in chondrules exhibit wide ranges of mg# = mg/(mg + fe), allowing to sub-divide porphyritic chondrules into either type i (mg# > 0.9) or type ii (mg# < 0.9). although both chondrule types formed under oxidizing conditions relative to the canonical solar n... | relationships between type i and type ii chondrules: implications on chondrule formation processes |
we present one-dimensional non-local thermodynamic equilibrium time-dependent radiative transfer simulations (using cmfgen) of two sub-chandrasekhar (sub-mch), one mch and one super-mch type ia sn ejecta models. three originate from mch delayed detonation models, and the fourth is a sub-mch detonation model. ejecta mas... | ejecta mass diagnostics of type ia supernovae |
the unidentified very-high-energy (vhe; e > 0.1 tev) γ-ray source, hess j1826-130, was discovered with the high energy stereoscopic system (hess) in the galactic plane. the analysis of 215 h of hess data has revealed a steady γ-ray flux from hess j1826-130, which appears extended with a half-width of 0.21° ± 0.02sta... | an extreme particle accelerator in the galactic plane: hess j1826-130 |
while the radiation mechanism of fast radio bursts (frbs) is unknown, coherent curvature radiation and synchrotron maser are promising candidates. we find that both radiation mechanisms work for a neutron star (ns) central engine with b ≳ 1012 g, while for a synchrotron maser, the central engine can also be an accretin... | fast radio burst counterparts and their implications for the central engine |
we investigate ztf18aalrxas, a double-peaked type iib core-collapse supernova (sn) discovered during science validation of the zwicky transient facility. ztf18aalrxas was discovered while the optical emission was still rising toward the initial cooling peak (0.7 mag over 2 days). our observations consist of multi-band ... | ztf18aalrxas: a type iib supernova from a very extended low-mass progenitor |
context. complex bipolar shapes can be generated either as a planetary nebula or a symbiotic system. the origin of the material ionised by the white dwarf is very different in these two scenarios, and it complicates the understanding of the morphologies of planetary nebulae.aims: the physical properties, structure, and... | a morpho-kinematic and spectroscopic study of the bipolar nebulae: m 2-9, mz 3, and hen 2-104 |
we have observed the pulsar in the crab nebula at high radio frequencies and high time resolution. we present continuously sampled data at 640 ns time resolution and individual bright pulses recorded at down to 0.25 ns time resolution. combining our new data with previous data from our group and from the literature sho... | the crab pulsar at centimeter wavelengths. i. ensemble characteristics |
the clash x-ray selected sample of 20 galaxy clusters contains 10 brightest cluster galaxies (bcgs) that exhibit significant (>5σ) extinction-corrected star formation rates (sfrs). star formation activity is inferred from photometric estimates of uv and hα+[n ii] emission in knots and filaments detected in clash hub... | star formation activity in clash brightest cluster galaxies |
in this work, we measure the lyα escape fraction of 935 [o iii]-emitting galaxies between 1.9 < z < 2.35 by comparing stacked spectra from the hubble space telescope/wfc3's near-ir grism to corresponding stacks from the hobby-eberly telescope dark energy experiment's internal data release 2. by measuring the stac... | the hetdex survey: the lyα escape fraction from 3d-hst emission-line galaxies at z ∼ 2 |
context. measuring star formation on a local scale is important to constrain star formation laws. it is not clear yet, however, whether and how the measure of star formation is affected by the spatial scale at which a galaxy is observed.aims: we wish to understand the impact of the resolution on the determination of th... | measuring star formation with resolved observations: the test case of m 33 |
we present a study of the galaxy environment of nine strong h i + c iv absorption line systems (16.2 < log(n(hi)) < 21.2) spanning a wide range in metallicity at z ∼ 4-5, using muse integral field and x-shooter spectroscopic data collected in a z ≈ 5.26 quasar field. we identify galaxies within a 250 kpc and ±100... | into the ly α jungle: exploring the circumgalactic medium of galaxies at z ∼ 4-5 with muse |
the first detected gravitational wave gw170817 from a binary neutron star merger is associated with an important optical transient at 2017gfo, which is a direct observation of kilonova. recent observations suggest that the remnant compact object of the binary neutron star merger associated with gw170817/grb 170817a may... | a pulsar wind nebula embedded in the kilonova at 2017gfo associated with gw170817/grb 170817a |
we present late-time hubble space telescope (hst) images of the site of supernova (sn) 2009ip taken almost 3 yr after its bright 2012 luminosity peak. sn 2009ip is now slightly fainter in broad filters than the progenitor candidate detected by hst in 1999. the current source continues to be dominated by ongoing late-ti... | massive stars dying alone: the extremely remote environment of sn 2009ip |
we search for far-infrared (fir) counterparts of known supernova remnants (snrs) in the galactic plane (360° in longitude and $b = \pm \, 1^{\circ }$ ) at 70-500 μm with herschel. we detect dust signatures in 39 snrs out of 190, made up of 13 core-collapse supernovae (ccsne), including 4 pulsar wind nebulae (pwne), and... | a complete catalogue of dusty supernova remnants in the galactic plane |
it has been demonstrated that planets belonging to the same close-in, compact multiple-planet system tend to exhibit a striking degree of uniformity in their sizes. a similar trend has also been found to hold for the masses of such planets, but considerations of such intra-system mass uniformity have generally been lim... | generalized peas in a pod: extending intra-system mass uniformity to non-ttv systems via the gini index |
context. dynamical interactions in young stellar clusters can eject massive stars early in their lives and significantly alter their mass functions. if all of the most massive stars are lost, we are left with an orphan cluster.aims: we study the bermuda cluster (villafranca o-014 nw), the most significant young stellar... | escape from the bermuda cluster: orphanization by multiple stellar ejections |
v392 persei is a known dwarf nova (dn) that underwent a classical nova eruption in 2018. here we report ground-based optical, swift uv and x-ray, and fermi-lat γ-ray observations following the eruption for almost three years. v392 per is one of the fastest evolving novae yet observed, with a t2 decline time of 2 d. ear... | v392 persei: a γ-ray bright nova eruption from a known dwarf nova |
in this work, we present a new catalogue of >40 000 ionised nebulae distributed across the 19 galaxies observed by the phangs-muse survey. the nebulae have been classified using a new model-comparison-based algorithm that exploits the odds ratio principle to assign a probabilistic classification to each nebula in th... | phangs-muse: detection and bayesian classification of40 000 ionised nebulae in nearby spiral galaxies |
cosmic ray electrons and positrons are tracers of particle propagation in the interstellar medium (ism). a recent measurement performed using the high energy stereoscopic system extends the all-electron (electron +positron ) spectrum up to 20 tev, probing very local sources and transport due to the ∼10 kyr cooling time... | undiscovered pulsar in the local bubble as an explanation of the local high energy cosmic ray all-electron spectrum |
in order to further elucidate possible temporal relationships between different varieties of calcium-, aluminum-rich inclusions (cais), we measured the aluminum-magnesium isotopic systematics of seven examples of the rare type known as forsterite-bearing type b (fob) inclusions from four different cv3 carbonaceous chon... | high precision al-mg systematics of forsterite-bearing type b cais from cv3 chondrites |
five type a cais from three cv3 chondrites (vigarano, northwest africa 3118, allende), which differ in age by no more than ∼105 years, show mineralogical and textural evidence of gradual transition into type bs, indicating that type b inclusions formed by evolution of type a cais in the solar nebula. this model differs... | the formation of type b cais: evolution from type a cais |
the large high altitude air shower observatory (lhaaso) is one of the most sensitive gamma-ray detector arrays, whose ultrahigh-energy (uhe) work bands not only help to study the origin and acceleration mechanism of uhe cosmic rays, but also provide the opportunity to test fundamental physics concepts such as lorentz s... | joint photon-electron lorentz violation parameter plane from lhaaso data |
we analyse a 3d hydrodynamic simulation of common envelope evolution to understand how energy is transferred between various forms and whether theory and simulation are mutually consistent given the set-up. virtually all of the envelope unbinding in the simulation occurs before the end of the rapid plunge-in phase, her... | energy budget and core-envelope motion in common envelope evolution |
we present atacama large millimeter/sub-millimeter array cycle-2 observations of the hbc 494 molecular outflow and envelope. hbc 494 is an fu ori-like object embedded in the orion a cloud and is associated with the reflection nebulae re50 and re50n. we use 12co, 13co and c18o spectral line data to independently describ... | the alma early science view of fuor/exor objects - ii. the very wide outflow driven by hbc 494 |
we use x-ray computed tomography (xct) to examine the 3d morphology and spatial relationship of fine-grained rims (fgrs) of type i chondrules in the cm carbonaceous chondrite murchison to investigate the formation setting (nebular vs. parent body) of the fgrs. we quantify the sizes, shapes, and orientations of the chon... | evidence for accretion of fine-grained rims in a turbulent nebula for cm murchison |
concerning the electroconvective analyte manipulation in microfluidics, we describe the basic physics of fluid flow driven by rotating induced-charge electro-osmosis (rot-iceo), which occurs on the planar surface of a single floating electrode in an external rotating electric field. first, based on a linear asymptotic ... | induced-charge electrokinetics in rotating electric fields: a linear asymptotic analysis |
supernova remnants (snrs) contain information on the influence of supernova explosions on dust properties. based on the color indices from the two micron all sky survey and the stellar parameters from the sdss-dr12/apache point observatory galactic evolution experiment and lamost-dr2/lamost experiment for galactic unde... | the distance to and the near-infrared extinction of the monoceros supernova remnant |
in this paper, we investigate the formation and growth of rayleigh-taylor instability (rti) in an ultra-dense celestial body like a neutron star which gradually accretes mass in it. such an accretion process occurs at the magnetospheric boundary of the accreting star. since the density is very high we have considered r... | growth of rt instability at the accreting magnetospheric boundary of neutron stars |
calcium-aluminum-rich inclusions (cais) are the oldest dated objects that formed inside the solar system. among these are rare, enigmatic objects with large mass-dependent fractionation effects (f cais), which sometimes also have large nucleosynthetic anomalies and a low initial abundance of the short-lived radionuclid... | a multielement isotopic study of refractory fun and f cais: mass-dependent and mass-independent isotope effects |
the 30 doradus nebula in the large magellanic cloud (lmc) contains the massive starburst cluster ngc 2070 with a massive and probably younger stellar sub clump at its centre: r136. it is not clear how such a massive inner cluster could form several million years after the older stars in ngc 2070, given that stellar fee... | forming clusters within clusters: how 30 doradus recollapsed and gave birth again |
we describe results from particle-in-cell simulations of driven turbulence in collisionless, magnetized, relativistic pair plasma. this physical regime provides a simple setting for investigating the basic properties of kinetic turbulence and is relevant for high-energy astrophysical systems such as pulsar wind nebulae... | numerical investigation of kinetic turbulence in relativistic pair plasmas - i. turbulence statistics |
the spectrometer on integral (spi) instrument has observed the hard x-ray sky from 20 kev up to a few mev for more than 15 yr. in this energy domain, the main emitters are compact objects for which spi provides spectral information of prime interest. recently, two transient sources reached very unusual flux levels and ... | on the high-energy emissions of compact objects observed with integral spi: event selection impact on source spectra and scientific results for the bright sources crab nebula, gs 2023+338 and maxi j1820+070 |
in this work we report deep muse observations of a broad absorption line (bal) quasar at z ∼ 5, revealing a ly α nebula with a maximum projected linear size of ∼60 kpc around the quasar (down to our 2σ sb limit per layer of ∼ 9× 10^{-19} erg s^{-1} cm^{-2} arcsec^{-2} for a 1 arcsec2 aperture). after correcting for the... | extended and broad ly α emission around a bal quasar at z ∼ 5 |
context. we have compiled a catalogue of central stars of planetary nebulae (cspn) with reliable distances and positions obtained from gaia data release 2 (dr2) astrometry. distances derived from parallaxes allow us to analyse the galactic distribution and estimate other parameters such as sizes, kinematical ages, bolo... | properties of central stars of planetary nebulae with distances in gaia dr2 |
we explain the early excess emission of the type ia supernova 2018oh by an interaction of the supernova ejecta with disk-originated matter (dom). such dom can form in the merger process of two white dwarfs in the double-degenerate scenario of type ia supernovae (sne ia). we find that an ejecta-dom interaction can fit t... | explaining the early excess emission of the type ia supernova 2018oh by the interaction of the ejecta with disk-originated matter |
context. the transient iptf15dtg is a type-ic supernova (sn) showing a broad light curve around maximum light, consistent with massive ejecta if we assume a radioactive-powering scenario.aims: we aim to study the late-time light curve of iptf15dtg, which turned out to be extraordinarily luminous for a stripped-envelope... | the luminous late-time emission of the type-ic supernova iptf15dtg - evidence for powering from a magnetar? |
nebular he ii emission implies the presence of energetic photons (e ≥ 54 ev). despite the great deal of effort dedicated to understanding he ii ionization, its origin has remained mysterious, particularly in metal-deficient star-forming (sf) galaxies. unfolding he ii-emitting, metal-poor starbursts at z ∼ 0 can yield i... | on the contribution of the x-ray source to the extended nebular he ii emission in izw18 |
we present an analysis of the photometry and spectroscopy of the host galaxy of swift-detected grb 080517. from our optical spectroscopy, we identify a redshift of z = 0.089 ± 0.003, based on strong emission lines, making this a rare example of a very local, low-luminosity, long gamma-ray burst. the galaxy is detected ... | grb 080517: a local, low-luminosity gamma-ray burst in a dusty galaxy at z = 0.09 |
the nature of the supernova leading to the crab nebula has long been controversial because of the low energy that is present in the observed nebula. one possibility is that there is significant energy in extended fast material around the crab but searches for such material have not led to detections. an electron captur... | evolution of the crab nebula in a low energy supernova |
we acquired spectra of 141 h ii regions in 10 late-type low surface brightness galaxies (lsbgs). the analysis of the chemical abundances obtained from the nebular emission lines shows that metallicity gradients are a common feature of lsbgs, contrary to previous claims concerning the absence of such gradients in this c... | abundance gradients in low surface brightness spirals: clues on the origin of common gradients in galactic discs |
context. a currently unsolved question in supernova (sn) research is the origin of stripped-envelope supernovae (sesne). such sne lack spectral signatures of hydrogen (type ib), or hydrogen and helium (type ic), indicating that the outer stellar layers have been stripped during their evolution. the mechanism for this i... | the molecular chemistry of type ibc supernovae and diagnostic potential with the james webb space telescope |
current methods of identifying the ionizing source of nebular emission in galaxies are well defined for the era of single-fiber spectroscopy, but still struggle to differentiate the complex and overlapping ionization sources in some galaxies. with the advent of integral field spectroscopy, the limits of these previous ... | beyond bpt: a new multidimensional diagnostic diagram for classifying power sources tested using the sami galaxy survey |
there are several studies proposing phenomenological consequences of a deformation of special and general relativity. here, we cast novel constraints on the deformation parameter of a metric in the cotangent bundle accounting for a curved momentum space. in an expanding universe, we study three possible observations th... | constraints on the deformation scale of a geometry in the cotangent bundle |
aims: we aim to study the presence of both rotation and expansion in post-agb nebulae, in particular around iw car, a binary post-agb star that was suspected to be surrounded by a keplerian disk.methods: we obtained high-quality alma observations of 12co and 13co j = 3-2 lines in iw car. the maps were analyzed by means... | a second post-agb nebula that contains gas in rotation and in expansion: alma maps of iw carinae |
herein we analyse late-time (post-plateau; 103 < t < 1229 d) optical spectra of low-redshift (z < 0.016), hydrogen-rich type iip supernovae (sne iip). our newly constructed sample contains 91 nebular spectra of 38 sne iip, which is the largest data set of its kind ever analysed in one study, and many of the ob... | after the fall: late-time spectroscopy of type iip supernovae |
we have mapped 12co j = 3-2 and other molecular lines from the “water fountain” bipolar pre-planetary nebula (ppn) iras 16342-3814 with ∼0.″35 resolution using atacama large millimeter/submillimeter array. we find (i) two very high-speed knotty, jet-like molecular outflows; (ii) a central high-density (> {few}× {10}... | alma observations of the water fountain pre-planetary nebula iras 16342-3814: high-velocity bipolar jets and an expanding torus |
the interaction between a pulsar wind nebula (pwn) and its host supernova remnant (snr) can produce a vast array of observable structures. asymmetry present within these structures derives from the complexity of the composite system, where many factors take turns playing a dominating hand throughout the stages of compo... | evolution of a pulsar wind nebula within a composite supernova remnant |
the scanning fabry-perot interferometer (fpi) - is the oldest method of optical 3d spectroscopy. it is still in use because of the high spectral resolution it provides over a large field of view. the history of the application of this method for the study of extended ob jects (nebulae and galaxies) and the technique of... | scanning fabry–perot interferometer of the 6-m sao ras telescope |
for the extremely bright lensed galaxy sdss j1723+3411 at z = 1.3293, we analyze spatially integrated mmt, keck, and hubble space telescope spectra that fully cover the rest-frame wavelength range of 1400-7200 å. we also analyze near-ir spectra from gemini that cover hα for a portion of the lensed arc. we report fluxes... | a comparison of rest-frame ultraviolet and optical emission-line diagnostics in the lensed galaxy sdss j1723+3411 at redshift z = 1.3293 |
we present an infrared (ir) characterization of the born-again planetary nebulae (pne) a 30 and a 78 using ir images and spectra. we demonstrate that the carbon-rich dust in a 30 and a 78 is spatially coincident with the h-poor ejecta and coexists with hot x-ray-emitting gas up to distances of 50 arcsec from the centra... | carbon dust in the evolved born-again planetary nebulae a 30 and a 78 |
in this work, we present photometric and spectroscopic data of the low-luminosity (ll) type iip supernova (sn) 2018hwm. the object shows a faint (mr = -15 mag) and very long (~130 d) plateau, followed by a 2.7 mag drop in the r band to the radioactive tail. the first spectrum shows a blue continuum with narrow balmer l... | low-luminosity type ii supernovae - iii. sn 2018hwm, a faint event with an unusually long plateau |
we present 3d hydrodynamic models of the interaction between the outflows of evolved, pulsating, asymptotic giant branch (agb) stars and nearby (<3 stellar radii) substellar companions (mcomp ≲ 40 mj). our models show that due to resonances between the orbital period of the companion and the pulsation period of the ... | 3d models of the circumstellar environments of evolved stars: formation of multiple spiral structures |
the nature of the sources powering nebular he ii emission in star-forming galaxies remains debated, and various types of objects have been considered, including wolf-rayet stars, x-ray binaries, and population iii stars. modern x-ray observations show the ubiquitous presence of hot gas filling star-forming galaxies. we... | ionization of he ii in star-forming galaxies by x-rays from cluster winds and superbubbles |
galactic pev cosmic-ray accelerators (pevatrons) are galactic sources theorized to accelerate cosmic rays up to pev in energy. the accelerated cosmic rays are expected to interact hadronically with nearby ambient gas or the interstellar medium, resulting in γ-rays and neutrinos. recently, the large high altitude air sh... | searches for neutrinos from large high altitude air shower observatory ultra-high-energy γ-ray sources using the icecube neutrino observatory |
integral field spectroscopy (ifs) provides a unique capability to spectroscopically study extended sources over a 2d field of view, but it also requires new techniques and tools. in this paper, we present an automatic code, spectroscopic analysis tool for integral field unit datacubes, satellite, designed to fully expl... | spectroscopic analysis tool for integral field unit datacubes (satellite): case studies of ngc 7009 and ngc 6778 with muse |
in this work we use the first data release of the gaia mission to explore the three-dimensional arrangement and age ordering of the many stellar groups toward the orion ob association, aiming at a new classification and characterization of the stellar population not embedded in the orion a and b molecular clouds. we ma... | mapping young stellar populations toward orion with gaia dr1 |
we present an aca search for [c i] 1-0 emission at 492 ghz toward large t tauri disks (gas radii ≳ 200 au) in the ~1-3 myr-old lupus star-forming region. combined with atacama large millimeter/submillimeter array 12 m archival data for im lup, we report [c i] 1-0 detections in six out of 10 sources, thus doubling the k... | large myr-old disks are not severely depleted of gas-phase co or carbon |
magnetic fields in the early solar system may have driven the inward accretion of the protoplanetary disk (ppd) and generated instabilities that led to the formation of planets and ring and gap structures. the allende carbonaceous chondrite meteorite records a strong early solar system magnetic field that has been inte... | the fine-scale magnetic history of the allende meteorite: implications for the structure of the solar nebula |
terrestrial planets (mercury, venus, earth, and mars) are differentiated into three layers: a metallic core, a silicate shell (mantle and crust), and a volatile envelope of gases, ices, and, for the earth, liquid water. each layer has different dominant elements (e.g., increasing iron content with depth and increasing ... | terrestrial planet compositions controlled by accretion disk magnetic field |
context. planet formation remains an open field of research, and many fundamental physical processes regarding planetary formation in protoplanetary disks are still imperfectly understood. it remains to be investigated how different conditions in these protoplanetary disks affect the emergence of different types of obs... | kepler-223 resonance holds information about turbulence during the gas-disk phase |
context. the fundamental metallicity relation (fmr) of galaxies is a 3d relation between the gas-phase metallicity, stellar mass, and star-formation rate (sfr). so far, it has only been studied for galaxies identified as star forming (sf) on the bpt diagrams (bpt-sf), but not for galaxies with li(n)er/agn classificatio... | the extension of the fundamental metallicity relation beyond the bpt star-forming sequence: evidence for both gas accretion and starvation |
mean motion commensurabilities in multi-planet systems are an expected outcome of protoplanetary disk-driven migration, and their relative dearth in the observational data presents an important challenge to current models of planet formation and dynamical evolution. one natural mechanism that can lead to the dissolutio... | an analytic criterion for turbulent disruption of planetary resonances |
massive stars that have been ejected from their parent cluster and supersonically sailing away through the interstellar medium (ism) are classified as exiled. they generate circumstellar bow-shock nebulae that can be observed. we present two-dimensional, axisymmetric hydrodynamical simulations of a representative sampl... | on the observability of bow shocks of galactic runaway ob stars |
we present an optical spectrum of the energetic type ib supernova (sn) 2012au obtained at an unprecedented epoch of 6.2 yr after explosion. forbidden transition emission lines of oxygen and sulfur are detected with expansion velocities of ≈2300 km s-1. the lack of narrow h balmer lines suggests that interaction with ci... | evidence for a pulsar wind nebula in the type ib peculiar supernova sn 2012au |
we present jansky very large array observations of 20-37 ghz absorption lines from nearby galactic diffuse molecular gas seen against four cosmologically distant compact radio continuum sources. the main new observational results are that l-c3h and ch3cn are ubiqitous in the local diffuse molecular interstellar medium ... | chemical complexity in local diffuse and translucent clouds: ubiquitous linear c3h and ch3cn, a detection of hc3n and an upper limit on the abundance of ch2cn |
we report new chandra x-ray observations of the shell supernova remnant kes 75 (g29.7-0.3) containing a pulsar and pulsar-wind nebula (pwn). expansion of the pwn is apparent across four epochs—2000, 2006, 2009, and 2016. we find an expansion rate between 2000 and 2016 of the northwest edge of the pwn of 0.249% ± 0.023%... | expansion and brightness changes in the pulsar-wind nebula in the composite supernova remnant kes 75 |
context. the abundance ratio n/o is a useful tool to study the interplay of galactic processes, for example star formation efficiency, timescale of infall, and outflow loading factor.aims: we aim to trace log(n/o) versus [fe/h] in the milky way and to compare this ratio with a set of chemical evolution models to unders... | the gaia-eso survey: the n/o abundance ratio in the milky way |
this study is dedicated to the systematic investigation of the effect of interferences on sr isotopic analyses in biological apatite and carbonate matrices using laser ablation multicollector inductively coupled plasma mass spectrometry (la-mc icp-ms). trends towards higher 87sr/86sr ratios for la-mc icp-ms compared to... | 87sr/86sr isotope ratio measurements by laser ablation multicollector inductively coupled plasma mass spectrometry: reconsidering matrix interferences in bioapatites and biogenic carbonates |
context. alma observations of the serpens south star-forming region suggest that stellar protoclusters may be completely mass segregated at birth. independent observations also suggest that embedded clusters form segregated by mass.aims: as the primordial mass segregation seems to be lost over time, we aim to study on ... | do star clusters form in a completely mass-segregated way? |
fast highly collimated outflows, including bipolar knots, jetlike features, and point-symmetric filaments or strings of knots, are common in planetary nebulae (pne). these features, generally known as jets, are thought to play an active role in the nebular shaping immediately before or while fast stellar winds and d-ty... | space velocity and time span of jets in planetary nebulae |
the black hole transient v404 cygni exhibited a bright outburst in june 2015 that was intensively followed over a wide range of wavelengths. our team obtained high time resolution optical spectroscopy (! ∼ ! 90 s), which included a detailed coverage of the most active phase of the event. we present a data base consisti... | the 1989 and 2015 outbursts of v404 cygni: a global study of wind-related optical features |
the microquasar ss433 features the most energetic jets known in our galaxy. a large fraction of the jet kinetic power is delivered to the surrounding w50 nebula at the jet termination shock, from which high-energy emission and cosmic-ray production have been anticipated. here, we report on the detection of a persistent... | detection of persistent gamma-ray emission toward ss433/w50 |
while several observational investigations have revealed the presence of magnetic fields in the circumstellar envelopes, jets and outflows of post-asymptotic giant branch stars (pagbs) and planetary nebulae, none has clearly demonstrated their presence at the stellar surface. the lack of information on the strength of ... | first detection of surface magnetic fields in post-agb stars: the cases of u monocerotis and r scuti |
a strong super-alfvénic drift of energetic particles (or cosmic rays) in a magnetized plasma can amplify the magnetic field significantly through nonresonant streaming instability (nrsi). while the traditional analysis is done for an ion current, here we use kinetic particle-in-cell simulations to study how the nrsi be... | lepton-driven nonresonant streaming instability |
we build a spitzer irac-complete catalog of objects complementing the ks-band selected ultravista catalog with objects detected in irac only. to identify massive (log ({{m}*}/{{m}⊙ })\gt 11) galaxies at 4\lt z\lt 7, we consider the systematic effects on photometric redshift measurements from the introduction of an old ... | stellar mass functions of galaxies at 4 < z < 7 from an irac-selected sample in cosmos/ultravista: limits on the abundance of very massive galaxies |
we report the first detection and high angular resolution (1.8″× 1.1″) imaging of acetic acid (ch3cooh) and ggg'-ethylene glycol (ggg'(ch2oh)2) toward the orion kleinmann-low (orion-kl) nebula. the observations were carried out at 1.3 mm with alma during cycle 2. a notable result is that the spatial distribution of the... | the complexity of orion: an alma view. ii. ggg'-ethylene glycol and acetic acid |
an analysis of the kinematics of ngc 6720 is performed on the commissioning data obtained with sitelle, the canada-france-hawaii telescope's new imaging fourier transform spectrometer. in order to measure carefully the small broadening effect of a shell expansion on an unresolved emission line, we have determined a com... | optimal fitting of gaussian-apodized or under-resolved emission lines in fourier transform spectra providing new insights on the velocity structure of ngc 6720 |
context. the large jet kinetic power and non-thermal processes occurring in the microquasar ss 433 make this source a good candidate for a very high-energy (vhe) gamma-ray emitter. gamma-ray fluxes above the sensitivity limits of current cherenkov telescopes have been predicted for both the central x-ray binary system ... | constraints on particle acceleration in ss433/w50 from magic and h.e.s.s. observations |
extreme high-frequency bl lacs (ehbl) feature their synchrotron peak of the broad-band spectral energy distribution (sed) at νs ≥ 1017 hz. the bl lac object 1es 2344+514 was included in the ehbl family because of its impressive shift of the synchrotron peak in 1996. during the following years, the source appeared to be... | an intermittent extreme bl lac: mwl study of 1es 2344+514 in an enhanced state |
wolf-rayet stars are advanced evolutionary stages of massive stars. despite their large mass-loss rates and high wind velocities, none of them displays a bow shock, although a fraction of them are classified as runaway. our 2.5-d numerical simulations of circumstellar matter around a $60\mbox{-}\rm m_{\odot }$ runaway ... | on the ring nebulae around runaway wolf-rayet stars |
we present nebular-phase spectra of the type ia supernova (sn ia) 2016brx, a member of the 1991bg-like subclass that lies at the faint end of the sn ia luminosity function. nebular spectra are available for only three other 1991bg-like sne, and their co line centres are all within ≲500 km s-1 of each other. in contrast... | a significantly off-centre 56ni distribution for the low-luminosity type ia supernova sn 2016brx from the 100ias survey |
massive ob stars are critical to the ecology of galaxies, and yet our knowledge of ob stars in the milky way, fainter than $v \sim 12$, remains patchy. data from the vst photometric h$\alpha$ survey (vphas+) permit the construction of the first deep catalogues of blue excess-selected ob stars, without neglecting the st... | the deep ob star population in carina from the vst photometric hα survey (vphas+) |
x-ray observations provide a potentially powerful tool to study starburst feedback. the analysis and interpretation of such observations remain challenging, however, due to various complications, including the non-isothermality of the diffuse hot plasma and the inhomogeneity of the foreground absorption. we here illust... | x-ray spectroscopy of the starburst feedback in 30 doradus |
extragalactic planetary nebulae (pne) offer a way to determine the distance to their host galaxies thanks to the nearly universal shape of the planetary nebulae luminosity function (pnlf). accurate pne distance measurements rely on obtaining well-sampled pnlfs and the number of observed pne scales with the encompassed ... | the fornax3d project: planetary nebulae catalogue and independent distance measurements to fornax cluster galaxies |
we present new images and continuum spectral analysis for 14 resolved galactic supernova remnants (snrs) selected from the 74 mhz very large array low-frequency sky survey redux (vlssr). we combine new integrated measurements from the vlssr with, when available, flux densities extracted from the galactic and extragalac... | thermal radio absorption as a tracer of the interaction of snrs with their environments |
extreme emission line galaxies (eelgs) are a notable galaxy genus, ultimately being regarded as local prototypes of early galaxies at the cosmic noon. robust characterisation of their stellar content, however, is hindered by the exceptionally high nebular emission present in their optical spectroscopic data. this study... | characterisation of the stellar content of sdss eelgs through self-consistent spectral modelling |
streaming instability is hypothesized to be triggered at particular protoplanetary disk locations where the volume density of the solid particles is enriched comparable to that of the gas. a ring of planetesimals thus forms when this condition is fulfilled locally. these planetesimals collide with each other and accret... | growth after the streaming instability: the radial distance dependence of the planetary growth |
recent observations by the large high altitude air shower observatory (lhaaso) have paved the way for the observational detection of pevatrons in the milky way, thus revolutionizing the field of γ-ray astrophysics. in this paper, we study one such detected source, lhaaso j1908+0621, and explore the origin of multi-tev ... | exploring the hadronic origin of lhaaso j1908+0621 |
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