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it is now clear that a binary evolutionary pathway is responsible for a significant fraction of all planetary nebulae, with some authors even going so far as to claim that binarity may be a near requirement for the formation of an observable nebula. this has led to the requirement that textbooks most likely need to be ... | the importance of binaries in the formation and evolution of planetary nebulae |
circumplanetary disks (cpds) may be essential to the formation of planets, regulating their spin and accretion evolution. we perform a series of 3d hydrodynamics simulations in both the isothermal and adiabatic limits to systematically measure the rotation rates, sizes, and masses of cpds as functions of {q}thermal}, t... | circumplanetary disk dynamics in the isothermal and adiabatic limits |
we present the discovery and analysis of sn\,2022oqm, a type ic supernova (sn) detected $<1$\,day after explosion. the sn rises to a blue and short-lived (2\,days) initial peak. early-time spectral observations of sn\,2022oqm show a hot (40,000\,k) continuum with high-ionization c and o absorption features at veloci... | sn 2022oqm -- a ca-rich explosion of a compact progenitor embedded in c/o circumstellar material |
we use the sphinx20 cosmological radiation hydrodynamics simulation to study how lyman continuum (lyc) photons escape from galaxies and the observational signatures of this escape. we define two classes of lyc leaker: bursty leakers and remnant leakers, based on their star formation rates (sfrs) that are averaged over ... | two modes of lyc escape from bursty star formation: implications for [c ii] deficits and the sources of reionization |
integral field units enable resolved studies of a large number of star-forming regions across entire nearby galaxies, providing insight on the conversion of gas into stars and the feedback from the emerging stellar populations over unprecedented dynamic ranges in terms of spatial scale, star-forming region properties, ... | the impact of pre-supernova feedback and its dependence on environment |
we study the evolution and final dispersal of protoplanetary discs that evolve under the action of internal and external photoevaporation, and different degrees of viscous transport. we identify five distinct dispersal pathways, which are (i) very long-lived discs ($\gt 20\,$ myr), (ii) inside-out dispersal where inter... | dispersal of protoplanetary discs: how stellar properties and the local environment determine the pathway of evolution |
context. the gaia early data release 3 (edr3), published in december 2020, features improved photometry and astrometry compared to that published in the previous dr2 file and includes a substantially larger number of sources, of the order of 2000 million, making it a paradigm of big data astronomy. many of the central ... | planetary nebulae in gaia edr3: central star identification, properties, and binarity |
in the core-accretion formation scenario of gas giants, most of the gas accreting onto a planet is processed through an accretion shock. in this series of papers we study this shock because it is key in setting the structure of the forming planet and thus its postformation luminosity, with dramatic observational conseq... | the planetary accretion shock. ii. grid of postshock entropies and radiative shock efficiencies for nonequilibrium radiation transport |
we examine the clustering and kinematics of young stellar objects (ysos) in the north america/pelican nebulae, as revealed by gaia astrometry, in relation to the structure and motions of the molecular gas, as indicated in molecular-line maps. the gaia parallaxes and proper motions allow us to significantly refine previ... | the formation of a stellar association in the ngc 7000/ic 5070 complex: results from kinematic analysis of stars and gas |
despite recent progress, the astrophysical channels responsible for rapid neutron capture (r-process) nucleosynthesis remain an unsettled question. observations of the kilonova following the gravitational-wave-detected neutron star merger gw170817 established mergers as one site of the r-process, but additional sources... | signatures of r-process enrichment in supernovae from collapsars |
the mg ii λλ2796, 2803 doublet is often used to measure interstellar medium absorption in galaxies, thereby serving as a diagnostic for feedback and outflows. however, the interpretation of mg ii remains confusing, due to resonant trapping and re-emission of the photons, analogous to lyα. therefore, in this paper, we p... | a close relationship between lyα and mg ii in green pea galaxies |
refractory organics are the main hosts of carbon, nitrogen, and other biogenic elements in primitive solar system material. we have synthesized refractory organics by ionizing a gas mixture reminiscent of the composition of the protosolar nebula, at temperatures up to 1,000 k in a plasma. synthesized compounds share ch... | synthesis of refractory organic matter in the ionized gas phase of the solar nebula |
the origin and evolution of planetary protoatmospheres in relation to the protoplanetary disk is discussed. the initial atmospheres of planets can mainly be related via two formation scenarios. if a protoplanetary core accretes mass and grows inside the gas disk, it can capture h2, he and other gases from the disk. whe... | formation and evolution of protoatmospheres |
this review provides useful background and information on how we find, vet and compile planetary nebulae (pne) candidates and verify them. it presents a summary of the known galactic pne population and their curation in the hong kong/aao/strasbourg/hα pne catalogue, "hash". it is a simple introduction for anyone intere... | planetary nebulae and how to find them: a concise review |
the morphology of planetary nebulae emerging from the common envelope phase of binary star evolution is investigated. using initial conditions based on the numerical results of hydrodynamical simulations of the common envelope phase, it was found that the shapes and sizes of the resulting nebula are very sensitive to t... | common envelope shaping of planetary nebulae |
we present a new catalogue of h ii regions based on the integral field spectroscopy (ifs) data of the extended califa and pisco samples. the selection of h ii regions was based on two assumptions: a clumpy structure with high contrast of h α emission and an underlying stellar population comprising young stars. the cata... | h ii regions in the califa survey: i. catalogue presentation |
a series of optical and one near-infrared nebular spectra covering the first year of the type ia supernova sn 2011fe are presented and modelled. the density profile that proved best for the early optical/ultraviolet spectra, `ρ-11fe', was extended to lower velocities to include the regions that emit at nebular epochs. ... | nebular spectra and abundance tomography of the type ia supernova sn 2011fe: a normal sn ia with a stable fe core |
sn 2018aoz is a type ia sn with a b-band plateau and excess emission in infant-phase light curves ≲1 day after the first light, evidencing an over-density of surface iron-peak elements as shown in our previous study. here, we advance the constraints on the nature and origin of sn 2018aoz based on its evolution until th... | the origin and evolution of the normal type ia sn 2018aoz with infant-phase reddening and excess emission |
the classic single-degenerate model for the progenitors of type ia supernova (sn ia) predicts that the supernova ejecta should be enriched with solar-like abundance material stripped from the companion star. spectroscopic observations of normal sne ia at late times, however, have not resulted in definite detection of h... | multidimensional models of type ia supernova nebular spectra: strong emission lines from stripped companion gas rule out classic single-degenerate systems |
context. dust attenuation shapes the spectral energy distribution of galaxies. it is particularly true for dusty galaxies in which stars experience a heavy attenuation. the combination of uv to ir photometry with the spectroscopic measurement of the hα recombination line helps to quantify dust attenuation of the whole ... | dust attenuation and hα emission in a sample of galaxies observed with herschel at 0.6 < z < 1.6 |
the ratios of strong rest-frame optical emission lines are the dominant indicator of metallicities in high-redshift galaxies. since typical strong-line based metallicity indicators are calibrated on auroral lines at $z=0$, their applicability for galaxies in the distant universe is unclear. in this paper, we make use o... | theoretical strong line metallicity diagnostics for the jwst era |
context. the chemical composition of planets is an important constraint for planet formation and subsequent differentiation. while theoretical studies try to derive the compositions of planets from planet formation models in order to link the composition and formation process of planets, other studies assume that the e... | elemental ratios in stars vs planets |
dust grains are classically thought to form in the winds of asymptotic giant branch (agb) stars. however, there is increasing evidence today for dust formation in supernovae (sne). to establish the relative importance of these two classes of stellar sources of dust, it is important to know the fraction of freshly forme... | dust grains from the heart of supernovae |
the wise catalog of galactic h ii regions contains ∼2000 h ii region candidates lacking ionized gas spectroscopic observations. all candidates have the characteristic h ii region mid-infrared morphology of wise 12 μ {{m}} emission surrounding 22 μ {{m}} emission, and additionally have detected radio continuum emission.... | finding distant galactic hii regions |
the discovery of planetary systems beyond our solar system has posed challenges to established theories of planetary formation. planetary orbits display a variety of architectures not predicted by first principles, and free-floating planets appear ubiquitous. the recent discovery of candidate jupiter mass binary object... | floating binary planets from ejections during close stellar encounters |
we present a first study based on the analysis of the deep spectra of ionized regions data base (desired). this is a compilation of 190 high signal-to-noise ratio optical spectra of $\mathrm{h\, \scriptstyle ii}$ regions and other photoionized nebulae, mostly observed with 8-10 m telescopes and containing ~29 380 emiss... | density biases and temperature relations for desired h ii regions |
we report the first measurements with sub-kiloparsec spatial resolution of strongly inverted gas-phase metallicity gradients in two dwarf galaxies at z ∼ 2. the galaxies have stellar masses ∼109{m}⊙ , specific star formation rate ∼20 gyr-1, and global metallicity 12+{log}({{o}}/{{h}})∼ 8.1 (1/4 solar), assuming the str... | discovery of strongly inverted metallicity gradients in dwarf galaxies at z ∼ 2 |
extreme, young stellar populations are considered to be the primary contributor to cosmic reionization. how the lyman continuum (lyc) escapes these galaxies remains highly elusive, and it is challenging to observe this process in actual lyc emitters without resolving the relevant physical scales. we investigate the sun... | small region, big impact: highly anisotropic lyman-continuum escape from a compact starburst region with extreme physical properties |
we use paschen-β (paβ; 1282 nm) observations from the hubble space telescope g141 grism to study the star formation and dust-attenuation properties of a sample of 29 low-redshift (z < 0.287) galaxies in the candels lyα emission at reionization survey. we first compare the nebular attenuation from paβ/hα with the ste... | clear: paschen-β star formation rates and dust attenuation of low-redshift galaxies |
context. strong nebular emission is ubiquitous in galaxies that contribute to cosmic reionization at redshift z ≳ 6. high-ionization uv metal lines, such as ciii]λ1908 å, show high equivalent widths (ew) in these early galaxies, suggesting harder radiation fields at low metallicity than low-z galaxies of similar stella... | the vandels survey: global properties of ciii]λ1908 å emitting star-forming galaxies at z ∼ 3 |
feo-poor (type i) porphyritic chondrules formed by incomplete melting of solid dust precursors via a yet-elusive mechanism. two settings are generally considered for their formation: (i) a nebular setting where primordial solids were melted, e.g. by shock waves propagating through the gas and (ii) a collisional planeta... | oxygen isotopic diversity of chondrule precursors and the nebular origin of chondrules |
previous studies have found that ∼1 deg2 fields surrounding the stellar aggregates in the taurus star-forming region exhibit a surplus of solar-mass stars relative to denser clusters like ic 348 and the orion nebula cluster. to test whether this difference reflects mass segregation in taurus or a variation in the initi... | a survey for new members of the taurus star-forming region with the sloan digital sky survey |
context. establishing the origin of the water d/h ratio in the solar system is central to our understanding of the chemical trail of water during the star and planet formation process. recent modeling suggests that comparisons of the d2o/hdo and hdo/h2o ratios are a powerful way to trace the chemical evolution of water... | alma observations of doubly deuterated water: inheritance of water from the prestellar environment |
we present photometric and spectroscopic observations of the nearby type ia sn 2019yvq, from its discovery ~1 day after explosion to ~100 days after its peak brightness. this sn exhibits several unusual features, most notably an extremely bright uv excess seen within ~5 days of its explosion. as seen in swift uv data, ... | a bright ultraviolet excess in the transitional 02es-like type ia supernova 2019yvq |
disk vortices have been heralded as promising routes for planet formation due to their ability to trap significant amounts of pebbles. while the gas motions and trapping properties of two-dimensional vortices have been studied in enough detail in the literature, pebble trapping in three dimensions has received less att... | pebble trapping in vortices: three-dimensional simulations |
we present a detailed spectroscopic analysis of a galaxy at z ≃ 4.88 that is, by chance, magnified ~30× by gravitational lensing. only three sources at z ≳ 5 are known with such high magnification. this particular source has been shown to exhibit widespread, high equivalent width ${{\rm c\, \small {iv}}}\ \lambda 1549\... | assessing the sources of reionization: a spectroscopic case study of a 30× lensed galaxy at z 5 with lyα, c iv, mg ii, and [ne iii] |
we provide new planetary nebula luminosity function (pnlf) distances to 19 nearby spiral galaxies that were observed with vlt/muse by the phangs collaboration. emission line ratios are used to separate planetary nebulae (pne) from other bright $[\mathrm{o}\, {\small iii}]$ emitting sources like compact supernovae remna... | planetary nebula luminosity function distances for 19 galaxies observed by phangs-muse |
context. the formation of gas giant planets by the accretion of 100 km diameter planetesimals is often thought to be inefficient. a diameter of this size is typical for planetesimals and results from self-gravity. many models therefore use small kilometer-sized planetesimals, or invoke the accretion of pebbles. further... | effect of pebble flux-regulated planetesimal formation on giant planet formation |
recently published episodic spectral (levesque and massey, 2020) and high angular resolution (montarges et al, 2020) observations of betelgeuse suggest that the deep minimum of 2019-2020 was caused by an enhanced dust abundance in the stellar atmosphere. detailed monitoring of such events may prove useful for construct... | differential speckle polarimetry of betelgeuse in 2019-2020: the rise is different from the fall |
we search for passive galaxies at z > 3 in the goods-south field, using different techniques based on photometric data, and paying attention to develop methods that are sensitive to objects that have become passive shortly before the epoch of observation. we use candels hst catalogues, ultra-deep ks data and new ira... | chasing passive galaxies in the early universe: a critical analysis in candels goods-south |
we present nebular spectra of the type ia supernova (sn ia) sn 2019yvq, which had a bright flash of blue and ultraviolet light after exploding, followed by a rise similar to other sne ia. although sn 2019yvq displayed several other rare characteristics, such as persistent high ejecta velocity near peak brightness, it w... | strong calcium emission indicates that the ultraviolet-flashing sn ia 2019yvq was the result of a sub-chandrasekar-mass double-detonation explosion |
the light curves of type ia supernovae (sne ia) are powered by the radioactive decay of 56ni to 56co at early times, and the decay of 56co to 56fe from ∼60 d after explosion. we examine the evolution of the [co iii] λ5893 emission complex during the nebular phase for sne ia with multiple nebular spectra and show that t... | measuring nickel masses in type ia supernovae using cobalt emission in nebular phase spectra |
there is a long history of using optical emission and absorption lines to constrain the metallicity and ionization parameters of gas in galaxies. however, comparable diagnostics are less well developed for the ultraviolet (uv). here, we assess the diagnostic potential of both absorption and emission features in the uv ... | stellar and nebular diagnostics in the ultraviolet for star-forming galaxies |
the nearby sn 2017eaw is a type ii-p (“plateau”) supernova (sn) showing early-time, moderate csm interaction. we present a comprehensive study of this sn, including the analysis of high-quality optical photometry and spectroscopy covering the very early epochs up to the nebular phase, as well as near-ultraviolet and ne... | the type ii-p supernova 2017eaw: from explosion to the nebular phase |
in this paper, we report the results of spectroscopic and photometric observations of the candidate evolved massive star mn48 disclosed via detection of a mid-infrared circular shell around it with the spitzer space telescope. follow-up optical spectroscopy of mn48 with the southern african large telescope (salt) carri... | mn48: a new galactic bona fide luminous blue variable revealed by spitzer and salt |
spatially resolved studies of high-redshift galaxies, an essential insight into galaxy formation processes, have been mostly limited to stacking or unusually bright objects. we present here the study of a typical (l*, m⋆ = 6 × 109 m⊙) young lensed galaxy at z = 3.5, observed with multi unit spectroscopic explorer (muse... | a young star-forming galaxy at z = 3.5 with an extended lyman α halo seen with muse |
early observations of type ia supernovae (sne ia) provide essential clues for understanding the progenitor system that gave rise to the terminal thermonuclear explosion. we present exquisite observations of sn 2019yvq, the second observed sn ia, after iptf 14atg, to display an early flash of emission in the ultraviolet... | the spectacular ultraviolet flash from the peculiar type ia supernova 2019yvq |
supernova (sn) 2016bdu is an unusual transient resembling sn 2009ip. sn 2009ip-like events are characterized by a long-lasting phase of erratic variability which ends with two luminous outbursts a few weeks apart. the second outburst is significantly more luminous (about 3 mag) than the first. in the case of sn 2016bdu... | supernovae 2016bdu and 2005gl, and their link with sn 2009ip-like transients: another piece of the puzzle |
we present a new multi-pixel high resolution (r ≳ 107) spectrometer for the stratospheric observatory for far-infrared astronomy (sofia). the receiver uses 2 × 7-pixel subarrays in orthogonal polarization, each in an hexagonal array around a central pixel. we present the first results for this new instrument after comm... | the upgreat 1.9 thz multi-pixel high resolution spectrometer for the sofia observatory |
context. models of stellar spectra are necessary for interpreting light from individual stars, planets, integrated stellar populations, nebulae, and the interstellar medium.aims: we provide a comprehensive and homogeneous collection of synthetic spectra for a wide range of atmospheric parameters and chemical compositio... | a collection of model stellar spectra for spectral types b to early-m |
as part of the 100ias survey, a program aimed to obtain nebular-phase spectra for a volume-limited and homogeneous sample of type ia supernovae (sne ia), we observed asassn-18tb (sn 2018fhw) at 139 d past maximum light. asassn-18tb was a fast-declining, sub-luminous event that fits well within the observed photometric ... | h α emission in the nebular spectrum of the type ia supernova asassn-18tb |
we present the first determination of the galaxy luminosity function (lf) at z ∼ 4, 5, 6, and 7, in the rest-frame optical at {λ }{rest}∼ 900 {nm} (z‧ band). the rest-frame optical light traces the content in low-mass evolved stars (∼stellar mass—m *), minimizing potential measurement biases for m *. moreover, it is le... | the rest-frame optical (900 nm) galaxy luminosity function at z ∼ 4-7: abundance matching points to limited evolution in the m star/m halo ratio at z ≥ 4 |
we present the palomar transient factory discoveries and the photometric and spectroscopic observations of ptf11kmb and ptf12bho. we show that both transients have properties consistent with the class of calcium-rich gap transients, specifically lower peak luminosities and rapid evolution compared to ordinary supernova... | two new calcium-rich gap transients in group and cluster environments |
we use a newly developed cascade model of turbulent concentration of particles in protoplanetary nebulae to calculate several properties of interest to the formation of primitive planetesimals and to the meteorite record. the model follows, and corrects, calculations of the primary initial mass function (imf) of planet... | cascade model for planetesimal formation by turbulent clustering |
context. this is the second paper of a series on galactic ob groups that uses astrometric and photometric data from gaia and spectral classifications from the galactic o-star spectroscopic survey (gosss) and the library of libraries of massive-star high-resolution spectra (lilimarlin). the previous paper was based on t... | the villafranca catalog of galactic ob groups. ii. from gaia dr2 to edr3 and ten new systems with o stars |
manga (mapping nearby galaxies at apache point observatory) is a 6-yr sloan digital sky survey (sdss-iv) survey that will obtain spatially resolved spectroscopy from 3600 to 10 300 å for a representative sample of over 10 000 nearby galaxies. in this paper, we present the analysis of nebular emission-line properties us... | p-manga galaxies: emission-lines properties - gas ionization and chemical abundances from prototype observations |
the magnetospheric multiscale mission observes, in detail, charged particle heating and substantial nonthermal acceleration in a region of strong turbulence ( $| \delta {\boldsymbol{b}}| /| {\boldsymbol{b}}| \sim 1$ , where ${\boldsymbol{b}}$ is the magnetic field) that surrounds a magnetic reconnection x-line. magneti... | observations of particle acceleration in magnetic reconnection-driven turbulence |
noble gases have played a key role in our understanding of the origin of earth's volatiles, mantle structure, and long-term degassing of the mantle. here we synthesize new insights into these topics gained from high-precision noble gas data. our analysis reveals new constraints on the origin of the terrestrial atmosphe... | noble gases: a record of earth's evolution and mantle dynamics |
we investigate the impact of the diffuse ionized gas (dig) on abundance determinations in star-forming (sf) galaxies. the dig is characterized using the h α equivalent width (wh α). from a set of 1 409 sf galaxies from the mapping nearby galaxies at apo (manga) survey, we calculate the fractional contribution of the di... | diffuse ionized gas and its effects on nebular metallicity estimates of star-forming galaxies |
context. the journey from dust particle to planetesimal involves physical processes acting on scales ranging from micrometers (the sticking and restructuring of aggregates) to hundreds of astronomical units (the size of the turbulent protoplanetary nebula). considering these processes simultaneously is essential when s... | a panoptic model for planetesimal formation and pebble delivery |
short gamma-ray bursts (sgrbs) are among the most luminous explosions in the universe and their origin still remains uncertain. observational evidence favors the association with binary neutron star or neutron star-black hole (ns-bh) binary mergers. leading models relate sgrbs to a relativistic jet launched by the bh-t... | short gamma-ray bursts in the "time-reversal" scenario |
we present an integral field unit survey of 73 galaxy clusters and groups with the visible multi object spectrograph on the very large telescope. we exploit the data to determine the h α gas dynamics on kpc scales to study the feedback processes occurring within the dense cluster cores. we determine the kinematic state... | optical emission line nebulae in galaxy cluster cores 1: the morphological, kinematic and spectral properties of the sample |
aims: we wish to investigate the physical properties of a sample of lyα emitting galaxies in the vandels survey, with particular focus on the role of kinematics and neutral hydrogen column density in the escape and spatial distribution of lyα photons.methods: from all the lyα emitting galaxies in the vandels data relea... | the vandels survey: the role of ism and galaxy physical properties in the escape of lyα emission in z ∼ 3.5 star-forming galaxies |
we investigated the ultraviolet (uv) spectral properties of faint lyman-α emitters (laes) in the redshift range 2.9 ≤ z ≤ 4.6, and we provide material to prepare future observations of the faint universe. we used data from the muse hubble ultra deep survey to construct mean rest-frame spectra of continuum-faint (median... | the muse hubble ultra deep field survey. xv. the mean rest-uv spectra of lyα emitters at z > 3 |
we present the results from a high-cadence, multiwavelength observation campaign of at 2016jbu (aka gaia16cfr), an interacting transient. this data set complements the current literature by adding higher cadence as well as extended coverage of the light-curve evolution and late-time spectroscopic evolution. photometric... | photometric and spectroscopic evolution of the interacting transient at 2016jbu(gaia16cfr) |
the cos legacy archive spectroscopic survey (classy) is designed to provide the community with a spectral atlas of 45 nearby star-forming galaxies that were chosen to cover similar properties to those seen at high z (z > 6). the prime high-level science product of classy is accurately coadded uv spectra, ranging fro... | classy. ii. a technical overview of the cos legacy archive spectroscopic survey |
of the long-lived chronometric systems, only the dual decay of 238u and 235u to 206pb and 207pb, respectively, have appropriate half-lives to resolve the ages of meteorites and their components formed in the first 5 myr of the solar system. this paper reviews the theory and methods behind this chronometer, offers crite... | pb-pb chronometry and the early solar system |
we identify 709 arc-shaped mid-infrared nebula in 24 μm spitzer space telescope or 22 μm wide field infrared explorer surveys of the galactic plane as probable dusty interstellar bowshocks powered by early-type stars. about 20% are visible at 8 μm or at shorter mid-infrared wavelengths. the vast majority (660) have no ... | a comprehensive search for stellar bowshock nebulae in the milky way: a catalog of 709 mid-infrared selected candidates |
a code computing consistently the evolution of stars, gas and dust, as well as the energy they radiate, is required to derive reliably the history of galaxies by fitting synthetic spectral energy distributions (seds) to multiwavelength observations. the new code pégase.3 described in this paper extends to the far-infra... | pégase.3: a code for modeling the uv-to-ir/submm spectral and chemical evolution of galaxies with dust |
metasurfaces, optics made from subwavelength-scale nanostructures, have been limited to millimeter-sizes by the scaling challenge of producing vast numbers of precisely engineered elements over a large area. in this study, we demonstrate an all-glass 100 mm diameter metasurface lens (metalens) comprising 18.7 billion n... | all-glass 100 mm diameter visible metalens for imaging the cosmos |
we present photoionization modeling of galaxy populations at z ∼ 0, 2, and >6 to bridge optical and far-infrared (fir) emission-line diagrams. we collect galaxies with measurements of optical and/or fir ([o iii] 88 μm and [c ii] 158 μm) emission-line fluxes and plot them on the [o iii]λ5007/hβ-[n ii]λ6585/hα (bpt) a... | bridging optical and far-infrared emission-line diagrams of galaxies from local to the epoch of reionization: characteristic high [o iii] 88 μm/sfr at z > 6 |
we report the first occurrence of a natural quasicrystal with decagonal symmetry. the quasicrystal, with composition al71ni24fe5, was discovered in the khatyrka meteorite, a recently described cv3 carbonaceous chondrite. icosahedrite, al63cu24fe13, the first natural quasicrystal to be identified, was found in the same ... | natural quasicrystal with decagonal symmetry |
the cb chondrites are metal-rich meteorites with characteristics that sharply distinguish them from other chondrite groups. their unusual chemical and petrologic features and a young formation age of bulk chondrules dated from the cba chondrite gujba are interpreted to reflect a single-stage impact origin. here, we rep... | pb-pb dating of individual chondrules from the cba chondrite gujba: assessment of the impact plume formation model |
we present the detection of persistent soft x-ray radiation with {l}x∼ {10}41-1042 erg s-1 at the location of the extremely luminous, double-humped transient asassn-15lh as revealed by chandra and swift. we interpret this finding in the context of observations from our multiwavelength campaign, which revealed the prese... | x-rays from the location of the double-humped transient asassn-15lh |
we present deep spectrophotometry of 18 h ii regions in the nearby massive spiral galaxies m 101 and m 31. we have obtained direct determinations of electron temperature in all the nebulae. we detect the c ii 4267 å line in several h ii regions, permitting to derive the radial gradient of c/h in both galaxies. we also ... | carbon, nitrogen, and oxygen abundance gradients in m101 and m31 |
gravitational-wave emission can lead to the coalescence of close pairs of compact objects orbiting each other1,2. in the case of neutron stars, such mergers may yield masses above the tolman-oppenheimer-volkoff limit (2 to 2.7 solar masses)3, leading to the formation of black holes4. for white dwarfs, the mass of the m... | a massive white-dwarf merger product before final collapse |
we combine state-of-the-art models for the production of stellar radiation and its transfer through the interstellar medium (ism) to investigate ultraviolet-line diagnostics of stars, the ionized and the neutral ism in star-forming galaxies. we start by assessing the reliability of our stellar population synthesis mode... | modelling ultraviolet-line diagnostics of stars, the ionized and the neutral interstellar medium in star-forming galaxies |
we present the detection of an unresolved radio source coincident with the position of the type i superluminous supernova (slsn) ptf10hgi (z = 0.098) about 7.5 yr post-explosion, with a flux density of fν (6 ghz) ≈ 47.3 μjy and a luminosity of lν (6 ghz) ≈ 1.1 × 1028 erg s-1 hz-1. this represents the first detection of... | a radio source coincident with the superluminous supernova ptf10hgi: evidence for a central engine and an analog of the repeating frb 121102? |
aims: this study aims at constraining the origin of the nearby type ia supernovae (sne), 2011fe and 2014j. the two most favoured scenarios for triggering the explosion of the white dwarf supernova progenitor is either mass loss from a non-degenerate companion or merger with another white dwarf. in the former, there cou... | no trace of a single-degenerate companion in late spectra of supernovae 2011fe and 2014j |
context. evolved low-mass stars lose a significant fraction of their mass through stellar winds. while the overall morphology of the stellar wind structure during the asymptotic giant branch (agb) phase is thought to be roughly spherically symmetric, the morphology changes dramatically during the post-agb and planetary... | alma data suggest the presence of spiral structure in the inner wind of cw leonis |
space observatories have provided unprecedented depictions of the many variability behaviors typical of low-mass, young stars. however, those studies have so far largely omitted more massive objects (~2 m⊙ to 4-5 m⊙) and were limited by the absence of simultaneous, multiwavelength information. we present a new study of... | multicolor variability of young stars in the lagoon nebula: driving causes and intrinsic timescales |
we present constraints on the physical properties (including stellar mass, age, and star formation rate) of 207 6 ≲ z ≲ 8 galaxy candidates from the reionization lensing cluster survey (relics) and spitzer-relics surveys. we measure photometry using t-phot and perform spectral energy distribution fitting using eazy and... | relics: properties of z ≥ 5.5 galaxies inferred from spitzer and hubble imaging, including a candidate z ∼ 6.8 strong [o iii] emitter |
to first order, the earth as well as other rocky planets in the solar system and rocky exoplanets orbiting other stars, are refractory pieces of the stellar nebula out of which they formed. to estimate the chemical composition of rocky exoplanets based on their stellar hosts' elemental abundances, we need a better unde... | the elemental abundances (with uncertainties) of the most earth-like planet |
the attenuation of starlight by dust in galactic environments is investigated through models of radiative transfer in a spherical, clumpy interstellar medium (ism). we show that the attenuation curves are primarily determined by the wavelength dependence of absorption rather than by the underlying extinction (absorptio... | radiative transfer model of dust attenuation curves in clumpy, galactic environments |
we investigate the integrated properties of massive (> 10 {m}⊙ ) rotating single-star stellar populations for a variety of initial rotation rates (v/{v}crit}=0.0, 0.2, 0.4, 0.5, and 0.6). we couple the new mesa isochrone and stellar tracks (mist) models to the flexible stellar population synthesis (fsps) package, ex... | the evolution and properties of rotating massive star populations |
magic, a system of two imaging atmospheric cherenkov telescopes, achieves its best performance under dark conditions, i.e. in absence of moonlight or twilight. since operating the telescopes only during dark time would severely limit the duty cycle, observations are also performed when the moon is present in the sky. h... | performance of the magic telescopes under moonlight |
tidal disruption and subsequent accretion of planetesimals by white dwarfs can reveal the elemental abundances of rocky bodies in exoplanetary systems. those abundances provide information on the composition of the nebula from which the systems formed, which is analogous to how meteorite abundances inform our understan... | lithium pollution of a white dwarf records the accretion of an extrasolar planetesimal |
we model pop iii star formation in different fuv and x-ray backgrounds, including radiation feedback from protostars. we confirm previous results that a moderate x-ray background increases the number of pop iii systems per unit cosmological volume, but masses and multiplicities of the system are reduced. the stellar ma... | population iii star formation in an x-ray background: iii. periodic radiative feedback and luminosity induced by elliptical orbits |
we present the first jwst observations of the z = 4.11 luminous radio galaxy tn j1338-1942, obtained as part of the 'prime extragalactic areas for reionization and lensing science' ('pearls') project. our nircam observations, designed to probe the key rest-frame optical continuum and emission line features at this reds... | jwst's pearls: tn j1338-1942 - i. extreme jet-triggered star formation in a z = 4.11 luminous radio galaxy |
to understand the mechanism behind high-z lyα nebulae, we simulate the scattering of lyα in a h i halo about a central lyα source. for the first time, we consider both smooth and clumpy distributions of halo gas, as well as a range of outflow speeds, total h i column densities, h i spatial concentrations, and central s... | radiative transfer in lyα nebulae. i. modeling a continuous or clumpy spherical halo with a central source |
the identification and localization of fast radio bursts (frbs) to their host galaxies have revealed important details about the progenitors of these mysterious, millisecond-long bursts of coherent radio emission. in this work, we study the most probable host galaxy of the apparently non-repeating chime/frb event frb 2... | the most probable host of chime frb 190425a, associated with binary neutron star merger gw190425, and a late-time transient search |
current and future cosmological surveys are targeting star-forming galaxies at z ∼ 1 with nebular emission lines. we use a state-of-the-art semi-analytical model of galaxy formation and evolution to explore the large-scale environment of star-forming emission line galaxies (elgs). model elgs are selected such that they... | do model emission line galaxies live in filaments at z ∼ 1? |
we present and describe the astro-photometric catalog of more than 800,000 sources found in the hubble tarantula treasury project (http). http is a hubble space telescope treasury program designed to image the entire 30 doradus region down to the sub-solar (∼0.5 m⊙) mass regime using the wide field camera 3 and the adv... | hubble tarantula treasury project. iii. photometric catalog and resulting constraints on the progression of star formation in the 30 doradus region |
the unprecedented astrometry from gaia's second data release (dr2) provides us with an opportunity to study molecular clouds in the solar neighbourhood in detail. extracting the wealth of information in these data remains a challenge, however. we have further improved our gaussian-processes-based, three-dimensional dus... | detailed 3d structure of orion a in dust with gaia dr2 |
we present an analysis of the newly identified μ tau association (muta) of young stars at ≃150 pc from the sun that is part of the large cas-tau structure, coeval and comoving with the α persei cluster. this association is also located in the vicinity of the taurus-auriga star-forming region and the pleiades associatio... | the μ tau association: a 60 myr old coeval group at 150 pc from the sun |
the analysis and combination of data from different gamma-ray instruments involves the use of collaboration proprietary software and case-by-case methods. the effort of defining a common data format for high-level data, namely event lists and instrument response functions (irfs), has recently started for very-high-ener... | towards open and reproducible multi-instrument analysis in gamma-ray astronomy |
we model particle growth in a turbulent, viscously evolving protoplanetary nebula, incorporating sticking, bouncing, fragmentation, and mass transfer at high speeds. we treat small particles using a moments method and large particles using a traditional histogram binning, including a probability distribution function o... | global modeling of nebulae with particle growth, drift, and evaporation fronts. i. methodology and typical results |
spatially resolved spectroscopy of the environments of explosive transients carries detailed information about the physical properties of the stellar population that gave rise to the explosion, and thus the progenitor itself. here, we present new observations of eso184-g82, the galaxy hosting the archetype of the γ-ray... | hot gas around sn 1998bw: inferring the progenitor from its environment |
the heart of the large magellanic cloud, 30 doradus, is a complex region with a clear core-halo structure. feedback from the stellar cluster r136 has been shown to be the main source of energy creating multiple parsec-scale expanding-shells in the outer region, and carving a nebula core in the proximity of the ionizati... | sofia observations of 30 doradus. ii. magnetic fields and large-scale gas kinematics |
we investigate dust attenuation and its dependence on viewing angle for 308 star-forming galaxies at 1.3 ≤ z ≤ 2.6 from the mosfire deep evolution field survey. we divide galaxies with a detected hα emission line and coverage of hβ into eight groups by stellar mass, star formation rate (sfr), and inclination (i.e., axi... | an updated dust-to-star geometry: dust attenuation does not depend on inclination in 1.3 ≤z ≤2.6 star-forming galaxies from mosdef |
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