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this tutorial explains the procedure used to analyze an optical emission-line spectrum produced by a nebula ionized by massive star formation. particularly, the methodology used to derive physical properties, such as electron density and temperature, and the ionic abundances of the most representative elements whose em... | ionized gaseous nebulae abundance determination from the direct method |
iron is the only polyvalent major element, and controls reduction-oxidation (redox) reactions in a host of geologic processes and reservoirs, from the mineral- to planetary-scale, on earth and in space. mass transfer of fe is often accompanied by changes in bonding environment, meaning the resultant variation in bond-s... | iron isotope systematics in planetary reservoirs |
we present the complete sample of stripped-envelope supernova (sn) spectra observed by the lick observatory supernova search (loss) collaboration over the last three decades: 888 spectra of 302 sne, 652 published here for the first time, with 384 spectra (of 92 sne) having photometrically determined phases. after corre... | the berkeley sample of stripped-envelope supernovae |
even though sn 2012cg is one of the best-studied type ia supernovae to date, the nature of its progenitor system has been debated in numerous studies. specifically, it is difficult to reconcile recent claims of the detection of a ∼6 {m}⊙ms companion with recent deep, late-time {{h}}α flux limits. in this study we add t... | strong evidence against a non-degenerate companion in sn 2012cg |
we present a new method to accurately describe the ionization fraction and the size distribution of polycyclic aromatic hydrocarbons (pahs) within astrophysical sources. to this purpose, we have computed the mid-infrared emission spectra of 308 pah molecules of varying sizes, symmetries, and compactness, generated in a... | probing the size and charge of polycyclic aromatic hydrocarbons |
we present vlt/x-shooter and muse spectroscopy of a faint f814w = 28.60 ± 0.33 ({m}{uv}=-17.0), low-mass (≲{10}7{m}⊙ ), and compact (r eff = 62 pc) freshly star-forming galaxy at z = 3.1169 magnified (16×) by the hubble frontier fields galaxy cluster abell s1063. gravitational lensing allows for a significant jump towa... | high-resolution spectroscopy of a young, low-metallicity optically thin l = 0.02l* star-forming galaxy at z = 3.12 |
we present the rest-frame optical spectroscopic properties of 60 faint (r ab ∼ 27; l ∼ 0.1 l *) lyα-selected galaxies (laes) at z ≈ 2.56. these laes also have rest-uv spectra of their lyα emission line morphologies, which trace the effects of interstellar and circumgalactic gas on the escape of lyα photons. we find tha... | the rest-frame optical spectroscopic properties of lyalpha-emitters at z~2.5: the physical origins of strong lyalpha emission |
most massive stars form in dense clusters where gravitational interactions with other stars may be common. the two nearest forming massive stars, the bn object and source i, located behind the orion nebula, were ejected with velocities of ∼29 and ∼13 km s-1 about 500 years ago by such interactions. this event generated... | the alma view of the omc1 explosion in orion |
the morphology of bipolar planetary nebulae (pne) can be attributed to interactions between a fast wind from the central engine and the dense toroidal-shaped ejecta left over from common envelope (ce) evolution. here we use the 3d hydrodynamic adaptive mesh refinement (amr) code astrobear to study the possibility that ... | bipolar planetary nebulae from outflow collimation by common envelope evolution |
the estimate of stellar metallicities (z*) of high-z galaxies are of paramount importance in order to understand the complexity of dust effects and the reciprocal interrelations among stellar mass, dust attenuation, stellar age, and metallicity. benefiting from uniquely deep far-uv spectra of > 500 star-forming gala... | the vandels survey: the relation between the uv continuum slope and stellar metallicity in star-forming galaxies at z ∼ 3 |
the moons instrument possesses an exceptional combination of large multiplexing, high sensitivity, broad simultaneous spectral coverage (from optical to near-infrared bands), large patrol area and high fibre density. these properties provide the unprecedented potential of enabling, for the very first time, sdss-like su... | moonrise: the main moons gto extragalactic survey |
within the general framework of the core-nucleated accretion theory of giant planet formation, the conglomeration of massive gaseous envelopes is facilitated by a transient period of rapid accumulation of nebular material. while the concurrent build-up of angular momentum is expected to leave newly formed planets spinn... | on the terminal rotation rates of giant planets |
as part of the accretion discs in hα with omegacam (adhoc) survey, we imaged a region of 12 × 8 square degrees around the orion nebula cluster in r, i and hα. thanks to the high-quality photometry obtained, we discovered three well-separated pre-main sequences in the color-magnitude diagram. the populations are all con... | a tale of three cities. omegacam discovers multiple sequences in the color-magnitude diagram of the orion nebula cluster |
we present new determinations of disk surface density, independent of an assumed dust opacity, for a sample of seven bright, diverse, protoplanetary disks using measurements of disk dust lines. we develop a robust method for determining the location of dust lines by modeling disk interferometric visibilities at multipl... | new constraints from dust lines on the surface densities of protoplanetary disks |
accurate distances are fundamental for interpreting various measured properties of galaxies. surprisingly, many of the best-studied spiral galaxies in the local volume have distance uncertainties that are much larger than can be achieved with modern observation techniques. using hubble space telescopeoptical imaging, w... | accurate distances to important spiral galaxies: m63, m74, ngc 1291, ngc 4559, ngc 4625, and ngc 5398 |
theory predicts that we should find fast, ejected (runaway) stars of all masses around dense, young star-forming regions. n-body simulations show that the number and distribution of these ejected stars could be used to constrain the initial spatial and kinematic substructure of the regions. we search for runaway and sl... | runaway and walkaway stars from the onc with gaia dr2 |
we present the results of the sloan digital sky survey apogee infrared spectroscopy of young nebulous clusters program (in-sync) survey of the orion a molecular cloud. this survey obtained high-resolution near-infrared spectroscopy of about 2700 young pre-main-sequence stars on a ∼ 6^\circ field of view. we have measur... | in-sync. iv. the young stellar population in the orion a molecular cloud |
we present spectra of 14 a-type supergiants in the metal-rich spiral galaxy m83. we derive stellar parameters and metallicities and measure a spectroscopic distance modulus μ =28.47+/- 0.10 (4.9 ± 0.2 mpc), in agreement with other methods. we use the stellar characteristic metallicity of m83 and other systems to discus... | young stars and ionized nebulae in m83: comparing chemical abundances at high metallicity. |
we present an analysis of the nebular spectra of 103 stripped-envelope (se) supernovae (sne) collected from the literature and observed with the subaru telescope from 2002 to 2012, focusing on [o i] λλ6300, 6363. the line profile and width of [o i] are employed to infer the ejecta geometry and the expansion velocity of... | statistical properties of the nebular spectra of 103 stripped-envelope core-collapse supernovae |
the enhancement of α elements such as oxygen is an important phase in the chemical evolution of the early universe, with nebular material becoming enriched in these elements sooner than iron. here, we present models which incorporate stellar spectra with α-enhanced compositions, focusing on the impact on the integrated... | the dependence of theoretical synthetic spectra on α-enhancement in young, binary stellar populations |
the fraction of lyman-α emitters (laes) among the galaxy population has been found to increase from z 0 to z 6 and drop dramatically at z> 6. this drop has been interpreted as an effect of an increasingly neutral intergalactic medium (igm) with increasing redshift, while a lyman continuum escape fraction evolving wi... | vlt/fors2 view at z 6: lyman-α emitter fraction and galaxy physical properties at the edge of the epoch of cosmic reionization |
using the exquisite data from the muse extremely deep field (mxdf), we report the discovery of an mg ii emission nebula with an area above a 2σ significance level of 1000 proper kpc2. this provides the first panoramic view of the spatial distribution of magnesium in the intragroup medium of a low-mass group of five sta... | the muse extremely deep field: first panoramic view of an mg ii emitting intragroup medium |
high temperature condensates found in meteorites display uranium isotopic variations (235u/238u) that complicate dating of the formation of the solar system and whose origin remains mysterious. it is possible that these variations are due to decay of the short-lived radionuclide 247cm (t1/2=15.6 myr) into 235u but they... | origin of uranium isotope variations in early solar nebula condensates |
we report the first gas-phase metallicity map of a distant galaxy measured with the james webb space telescope (jwst). we use the niriss slitless spectroscopy acquired by the glass early release science program to spatially resolve the rest-frame optical nebular emission lines in a gravitationally lensed galaxy at z = ... | early results from glass-jwst. iv. spatially resolved metallicity in a low-mass z 3 galaxy with niriss |
context. early-type galaxies (etgs) are found to follow a wide variety of merger and accretion histories in cosmological simulations.aims: we characterize the photometric and kinematic properties of simulated etg stellar halos, and compare them to the observations.methods: we selected a sample of 1114 etgs in the tng10... | the stellar halos of etgs in the illustristng simulations: the photometric and kinematic diversity of galaxies at large radii |
escaping lyman continuum photons from galaxies likely reionized the intergalactic medium at redshifts z ≳ 6. however, the lyman continuum is not directly observable at these redshifts and secondary indicators of lyman continuum escape must be used to estimate the budget of ionizing photons. observationally, at redshift... | the lyman continuum escape survey: connecting time-dependent [o iii] and [o ii] line emission with lyman continuum escape fraction in simulations of galaxy formation |
we present photometric and spectroscopic observations of the unusual type ia supernova asassn-18tb, including a series of southern african large telescope spectra obtained over the course of nearly six months and the first observations of a supernova by the transiting exoplanet survey satellite. we confirm a previous o... | asassn-18tb: a most unusual type ia supernova observed by tess and salt |
we review recent advances in our understanding of magnetism in the solar nebula and protoplanetary disks (ppds). we discuss the implications of theory, meteorite measurements, and astronomical observations for planetary formation and nebular evolution. paleomagnetic measurements indicate the presence of fields of 0.54 ... | history of the solar nebula from meteorite paleomagnetism |
we present the census of the local universe (clu) narrowband survey to search for emission-line (hα) galaxies. clu-hα has imaged ≈3π of the sky (26,470 deg2) with four narrowband filters that probe a distance out to 200 mpc. we have obtained spectroscopic follow-up for galaxy candidates in 14 preliminary fields (101.6 ... | census of the local universe (clu) narrowband survey. i. galaxy catalogs from preliminary fields |
the detonation of a helium shell on a white dwarf (wd) has been proposed as a possible explosion triggering mechanism for sne ia. here, we report ztf 18aaqeasu (sn 2018byg/atlas 18pqq), a peculiar type i supernova, consistent with being a helium-shell double-detonation. with a rise time of ≈18 days from explosion, the ... | ztf 18aaqeasu (sn2018byg): a massive helium-shell double detonation on a sub-chandrasekhar-mass white dwarf |
the sensitivity and angular resolution of photometric surveys executed by the hubble space telescope (hst) enable studies of individual star clusters in galaxies out to a few tens of megaparsecs. the fitting of spectral energy distributions (seds) of star clusters is essential for measuring their physical properties an... | phangs-hst: star cluster spectral energy distribution fitting with cigale |
the so-called jellyfish galaxies are objects exhibiting disturbed morphology, mostly in the form of tails of gas stripped from the main body of the galaxy. several works have strongly suggested ram pressure stripping to be the mechanism driving this phenomenon. here, we focus on one of these objects, drawn from a sampl... | gasp. iii. jo36: a case of multiple environmental effects at play? |
the relationship between galaxy characteristics and the reionization of the universe remains elusive, mainly due to the observational difficulty in accessing the lyman continuum (lyc) at these redshifts. it is thus important to identify low-redshift lyc-leaking galaxies that can be used as laboratories to investigate t... | the low-redshift lyman-continuum survey: [s ii] deficiency and the leakage of ionizing radiation |
core accretion is the conventional model for the formation of the gas giant planets. the model may also apply to the icy giant planets, uranus and neptune, except that it may take upward of 50 myr for them to form at their present orbital distances, which is beyond the maximum 5 myr lifetime of the solar nebula. a plau... | deep atmosphere composition, structure, origin, and exploration, with particular focus on critical in situ science at the icy giants |
the increasing neutrality of the intergalactic medium at z > 6 suppresses lyα emission, and spectroscopic confirmation of galaxy redshifts requires the detection of alternative ultraviolet lines. the strong [c iii] λ1907+c iii] λ1909 doublet frequently observed in low-metallicity, actively star-forming galaxies is a... | photoionization models for the semi-forbidden c iii] 1909 emission in star-forming galaxies |
understanding the origin of life-essential volatiles such as nitrogen (n) in the solar system and beyond is critical to evaluate the potential habitability of rocky planets1-5. whether the inner solar system planets accreted these volatiles from their inception or had an exogenous delivery from the outer solar system i... | a very early origin of isotopically distinct nitrogen in inner solar system protoplanets |
we analyse the rest-optical emission-line spectra of z ~ 2.3 star-forming galaxies in the complete mosfire deep evolution field (mosdef) survey. in investigating the origin of the well-known offset between the sequences of high-redshift and local galaxies in the [o iii]λ5008/hβ versus [n ii]λ6585/hα ('[n ii] bpt') diag... | the mosdef survey: a comprehensive analysis of the rest-optical emission-line properties of z ∼ 2.3 star-forming galaxies |
we study the spectroscopic evolution of superluminous supernovae (slsne) later than 100 days after maximum light. we present new data for gaia16apd and sn 2017egm and analyze these with a larger sample comprising 41 spectra of 12 events. the spectra become nebular within 2-4 e-folding times after light-curve peak, with... | nebular-phase spectra of superluminous supernovae: physical insights from observational and statistical properties |
while interaction with circumstellar material is known to play an important role in type iin supernovae (sne), analyses of the more common sne iip and iil have not traditionally included interaction as a significant power source. however, recent campaigns to observe sne within days of explosion have revealed narrow emi... | short-lived circumstellar interaction in the low-luminosity type iip sn 2016bkv |
recent developments in planet formation theory and measurements of low d/h in deep mantle material support a solar nebula source for some of earth's hydrogen. here we present a new model for the origin of earth's water that considers both chondritic water and nebular ingassing of hydrogen. the largest embryo that forme... | origin of earth's water: chondritic inheritance plus nebular ingassing and storage of hydrogen in the core |
the source responsible for the reionization of the universe is believed to be the population of star-forming galaxies at z ∼ 6 to 12. the biggest uncertainty concerns the fraction of lyman-continuum photons that actually escape from the galaxies. in recent years, several relatively small samples of “leaky” galaxies hav... | a new technique for finding galaxies leaking lyman-continuum radiation: [s ii]-deficiency |
the terrestrial planets are believed to have formed by violent collisions of tens of lunar- to mars-size protoplanets at time t < 200 myr after the protoplanetary gas disk dispersal (t0). the solar system giant planets rapidly formed during the protoplanetary disk stage and, after t0, radially migrated by interactin... | the role of early giant-planet instability in terrestrial planet formation |
context. planetary nebulae (pne) are a brief but important phase of stellar evolution. the study of galactic pne has historically been hampered by uncertain distances, but the parallaxes of pn central stars (cspne) measured by gaia are improving the situation.aims: gaia's early data release 3 (edr3) offers higher astro... | one star, two star, red star, blue star: an updated planetary nebula central star distance catalogue from gaia edr3 |
following our recent work on type ii supernovae (sne), we present a set of 1d nonlocal thermodynamic equilibrium radiative transfer calculations for nebular-phase type ibc sne starting from state-of-the-art explosion models with detailed nucleosynthesis. our grid of progenitor models is derived from he stars that were ... | nebular phase properties of supernova ibc from he-star explosions |
by incorporating our major recent discoveries with re-measured and verified contents of existing catalogues we provide, for the first time, an accessible, reliable, on-line sql database for essential, up-to date information for all known galactic planetary nebulae (pne). we have attempted to: i) reliably remove pn mimi... | hash: the hong kong/aao/strasbourg hα planetary nebula database |
a current issue in the study of planetary nebulae with close binary central stars (css) is the extent to which the binaries affect the shaping of the nebulae. recent studies have begun to show a high coincidence rate between nebulae with large-scale axial or point symmetries and close binary stars. in addition, combine... | observational confirmation of a link between common envelope binary interaction and planetary nebula shaping |
η carinae is an extraordinary massive star famous for its 19th century great eruption and the surrounding homunculus nebula ejected in that event. the cause of this eruption has been the centre of a long-standing mystery. recent observations, including light-echo spectra of the eruption, suggest that it most likely res... | simulating the formation of η carinae's surrounding nebula through unstable triple evolution and stellar merger-induced eruption |
nucleosynthetic isotope anomalies in bulk chondrites and differentiated meteorites reflect variable proportions of isotopically diverse presolar components in bulk planetary bodies, but the origin of these heterogeneities is not well understood. here, the ru isotope composition of a comprehensive suite of iron meteorit... | ru isotope heterogeneity in the solar protoplanetary disk |
type iax supernovae (sn iax), also called sn 2002cx-like supernovae, are the largest class of "peculiar" white dwarf (thermonuclear) supernovae, with over 50 members known. sn iax have lower ejecta velocity and lower luminosities, and these parameters span a much wider range, than normal type ia supernovae (sn ia). sn ... | type iax supernovae |
we compute synthetic optical and ultraviolet (uv) emission-line properties of galaxies in a full cosmological framework by coupling, in post-processing, new-generation nebular-emission models with high-resolution, cosmological zoom-in simulations of massive galaxies. our self-consistent modelling accounts for nebular e... | synthetic nebular emission from massive galaxies - ii. ultraviolet-line diagnostics of dominant ionizing sources |
we present a study of the thermal structure of the hot x-ray emitting atmospheres for a sample of 49 nearby x-ray and optically bright elliptical galaxies using chandra x-ray data. we focus on the connection between the properties of the hot x-ray emitting gas and the cooler h α+[n ii] emitting phase, and the possible ... | thermodynamic properties, multiphase gas, and agn feedback in a large sample of giant ellipticals |
identifying low-redshift galaxies that emit lyman continuum radiation (lyc leakers) is one of the primary, indirect methods of studying galaxy formation in the epoch of reionization. however, not only has it proved challenging to identify such systems, it also remains uncertain whether the low-redshift lyc leakers are ... | new methods for identifying lyman continuum leakers and reionization-epoch analogues |
early-time radiative signals from type ia supernovae (sne ia) can provide important constraints on the explosion mechanism and the progenitor system. we present observations and analysis of sn 2019np, a nearby sn ia discovered within 1-2 days after the explosion. follow-up observations were conducted in optical, ultrav... | observations of the very young type ia supernova 2019np with early-excess emission |
local star-forming galaxies show properties that are thought to differ from galaxies in the early universe. among them, the ionizing stellar populations and the gas geometry make the recipes designed to derive chemical abundances from nebular emission lines to differ from those calibrated in the local universe. a sampl... | extreme emission-line galaxies in sdss - i. empirical and model-based calibrations of chemical abundances |
we present a detailed analysis of 317 2.0 ≤ z ≤ 2.7 star-forming galaxies from the keck baryonic structure survey. using complementary spectroscopic observations with keck/lris and keck/mosfire, as well as spectral energy distribution (sed) fits to broadband photometry, we examine the joint rest-uv and rest-optical pro... | dust attenuation, star formation, and metallicity in z ∼ 2-3 galaxies from kbss-mosfire |
the discrepancy between abundances computed using optical recombination lines and collisionally excited lines is a major unresolved problem in nebular astrophysics. here, we show that the largest abundance discrepancies are reached in planetary nebulae with close binary central stars. we illustrate this using deep spec... | binarity and the abundance discrepancy problem in planetary nebulae |
calcium is a major element of the earth, the moon, terrestrial planets, and rocky meteorites. here we present equilibrium ca isotope fractionation factors of ca-bearing minerals using the first-principles calculations based on density functional theory (dft). the sequence of minerals from the isotopically heaviest to t... | first-principles calculations of equilibrium ca isotope fractionation: implications for oldhamite formation and evolution of lunar magma ocean |
we present c and o abundances in the magellanic clouds derived from deep spectra of h ii regions. the data have been taken with the ultraviolet-visual echelle spectrograph at the 8.2-m very large telescope. the sample comprises five h ii regions in the large magellanic cloud (lmc) and four in the small magellanic cloud... | carbon and oxygen in h ii regions of the magellanic clouds: abundance discrepancy and chemical evolution |
in this work, we propose an accreting stellar binary model for understanding the active periodic fast radio bursts (frbs). the system consists of a stellar compact object (co) and a donor star (ds) companion in an eccentric orbit, where the ds fills its own roche lobe near the periastron. the co accretes the material f... | an accreting stellar binary model for active periodic fast radio bursts |
we have investigated the global dynamical state of the integral shaped filament in the orion a cloud using new n2h+ (1-0) large-scale, iram 30 m observations. our analysis of its internal gas dynamics reveals the presence of accelerated motions towards the orion nebula cluster, showing a characteristic blue-shifted pro... | gravitational collapse of the omc-1 region |
himiko is one of the most luminous lyα emitters at z = 6.595. it has three star-forming clumps detected in the rest-frame uv, with a total sfr = 20 m ⊙ yr-1. we report the atacama large millimeter/submillimeter array (alma) detection of the [c ii]158 μm line emission in this galaxy with a significance of 8σ. the total ... | alma detection of extended [c ii] emission in himiko at z = 6.6 |
we present 5-20 μm spectral maps of the reflection nebula ngc 2023 obtained with the infrared spectrograph sl and sh modes on board the spitzer space telescope, which reveal emission from polycyclic aromatic hydrocarbons (pahs), c60, and h2 superposed on a dust continuum. we show that several pah emission bands correla... | the pah emission characteristics of the reflection nebula ngc 2023 |
we present the results of an lyα profile analysis of 12 lyα emitters (laes) at z∼ 2.2 with high-resolution lyα spectra. we find that all 12 objects have an lyα profile with the main peak redward of the systemic redshift defined by nebular lines, and five have a weak, secondary peak blueward of the systemic redshift (bl... | a close comparison between observed and modeled lyα lines for z ~ 2.2 lyα emitters |
we investigate whether triggering of the magnetorotational instability (mri) in protoplanetary discs can account for the wide diversity of observed accretion outbursts. we show that short-lived, relatively low accretion rate events probably result from triggering in the inner disc and can occur at low surface densities... | magnetically activated accretion outbursts of pre-main-sequence discs |
chondrules may have played a critical role in the earliest stages of planet formation by mediating the accumulation of dust into planetesimals. however, the origin of chondrules and their significance for planetesimal accretion remain enigmatic. here, we show that chondrules and matrix in the carbonaceous chondrite all... | tungsten isotopic constraints on the age and origin of chondrules |
we present results of our large-scale, optical, multi-epoch photometric survey across ∼180 square degrees in the orion ob1 association, complemented with extensive follow-up spectroscopy. our focus is mapping and characterizing the off-cloud, low-mass, pre-main-sequence (pms) populations. we report 2062 k- and m-type c... | the cida variability survey of orion ob1. ii. demographics of the young, low-mass stellar populations |
strong high-ionization lines such as he ii of young galaxies are puzzling at high and low redshift. although recent studies suggest the existence of nonthermal sources, whether their ionizing spectra can consistently explain multiple major emission lines remains a question. here we derive the general shapes of the ioni... | empress. vii. ionizing spectrum shapes of extremely metal-poor galaxies: uncovering the origins of strong he ii and the impact on cosmic reionization |
the remarkable discovery by the chandra x-ray observatory that the crab nebula's jet periodically changes direction provides a challenge to our understanding of astrophysical jet dynamics. it has been suggested that this phenomenon may be the consequence of magnetic fields and magnetohydrodynamic instabilities, but exp... | scaled laboratory experiments explain the kink behaviour of the crab nebula jet |
we discover clear doubly peaked line profiles in 3 out of ∼20 type ia supernovae (sne ia) with high-quality nebular-phase spectra. the profiles are consistently present in three separated co/fe emission features. the two peaks are respectively blueshifted and redshifted relative to the host galaxies and are separated b... | type ia supernovae with bimodal explosions are common - possible smoking gun for direct collisions of white dwarfs. |
we report the dramatic mid-infrared brightening between 2004 and 2006 of herschel orion protostar survey (hops) 383, a deeply embedded protostar adjacent to ngc 1977 in orion. by 2008, the source became a factor of 35 brighter at 24 μm with a brightness increase also apparent at 4.5 μm. the outburst is also detected in... | hops 383: an outbursting class 0 protostar in orion |
the bulk chemical compositions of planets are uncertain, even for major elements such as mg and si. this is due to the fact that the samples available for study all originate from relatively shallow depths. comparison of the stable isotope compositions of planets and meteorites can help overcome this limitation. specif... | planetary and meteoritic mg/si and δ30 si variations inherited from solar nebula chemistry |
we investigate mass transfer and the formation of discs in binary systems using a combination of numerical simulations and theory. we consider six models distinguished by binary separation, secondary mass and outflow mechanism. each system consists of an asymptotic giant branch (agb) star and an accreting secondary. th... | mass transfer and disc formation in agb binary systems |
"i do not believe that even in a snowflake this ordered pattern exists at random." – johannes kepler one of the most important developments in exoplanet science in the past decade is the discovery of multi-planet systems with sub-neptune-sized planets interior to 1 au. this chapter explores the architectures of these p... | architectures of compact multi-planet systems: diversity and uniformity |
pyneb is a python package widely used to model emission lines in gaseous nebulae. we take advantage of its object-oriented architecture, class methods, and historical atomic database to structure a practical environment for atomic data assessment. our aim is to reduce the uncertainties in the parameter space (line rati... | atomic data assessment with pyneb |
aims: we perform an extensive characterization of the broadband emission of mrk 421, as well as its temporal evolution, during the non-flaring (low) state. the high brightness and nearby location (z = 0.031) of mrk 421 make it an excellent laboratory to study blazar emission. the goal is to learn about the physical pro... | the 2009 multiwavelength campaign on mrk 421: variability and correlation studies |
the large high altitude air shower observatory (lhaaso) recently reported the detection of gamma-ray emissions with energies up to 1.1pev from the crab nebula. using the absence of vacuum cherenkov effect by inverse-compton electrons, we improve previous bounds to linear-order lorentz invariance violation (lv) in the d... | testing lorentz invariance of electrons with lhaaso observations of pev gamma-rays from the crab nebula |
placs (platy hibonite crystals) and related hibonite-rich calcium-, aluminum-rich inclusions (cais; hereafter collectively referred to as plac-like cais) have the largest nucleosynthetic isotope anomalies of all materials believed to have formed in the solar system. most plac-like cais have low inferred initial 26al/27... | a link between oxygen, calcium and titanium isotopes in 26al-poor hibonite-rich cais from murchison and implications for the heterogeneity of dust reservoirs in the solar nebula |
context. in the hierarchical two-phase formation scenario, the halos of early type galaxies (etgs) are expected to have different physical properties from the galaxies' central regions.aims: the epn.s survey characterizes the kinematic properties of etg halos using planetary nebulae (pne) as tracers, overcoming the lim... | the extended planetary nebula spectrograph (epn.s) early-type galaxy survey: the kinematic diversity of stellar halos and the relation between halo transition scale and stellar mass |
we use the light curve and spectral synthesis code jekyll to calculate a set of macroscopically mixed type iib supernova (sn) models, which are compared to both previously published and new late-phase observations of sn 2020acat. the models differ in the initial mass, the radial mixing and expansion of the radioactive ... | lightcurve and spectral modelling of the type iib sn 2020acat. evidence for a strong ni bubble effect on the diffusion time |
we present linear polarimetry for seven hydrogen-poor superluminous supernovae (slsne-i) of which only one has previously published polarimetric data. the best-studied event is sn 2017gci, for which we present two epochs of spectropolarimetry at +3 d and +29 d post-peak in rest frame, accompanied by four epochs of imag... | polarimetry of hydrogen-poor superluminous supernovae |
we present observations of sn 2022joj, a peculiar type ia supernova discovered by the zwicky transient facility. sn 2022joj exhibits an unusually red g ztf - r ztf color at early times and a rapid blueward evolution afterward. around maximum brightness, sn 2022joj shows a high luminosity ( ${m}_{{g}_{\mathrm{ztf}},\max... | sn 2022joj: a peculiar type ia supernova possibly driven by an asymmetric helium-shell double detonation |
pattern formation is a ubiquitous phenomenon in nature, from the organization of stellar nebulae to the structuration of clouds or the growth of plants. a key mechanism through which order can emerge from a homogeneous system is a parametric instability, with a paradigmatic example being the formation of faraday waves ... | emergence of tunable periodic density correlations in a floquet-bloch system |
new horizon's accurate determination of the sizes and densities of pluto and charon now permit precise internal models of both bodies to be constructed. assuming differentiated rock-ice structures, we find that pluto is close to 2/3 solar-composition anhydrous rock by mass and charon 3/5 solar-composition anhydrous roc... | origin of the pluto-charon system: constraints from the new horizons flyby |
we present the results of a detailed, systematic stellar evolution study of binary mergers for blue supergiant (bsg) progenitors of type ii supernovae. in particular, these are the first evolutionary models that can simultaneously reproduce nearly all observational aspects of the progenitor of sn 1987a, $\text{sk}-69\,... | the quest for blue supergiants: binary merger models for the evolution of the progenitor of sn 1987a. |
in this work, bvri light curves of 55 type ii supernovae (sne ii) from the lick observatory supernova search programme obtained with the katzman automatic imaging telescope and the 1 m nickel telescope from 2006 to 2018 are presented. additionally, more than 150 spectra gathered with the 3 m shane telescope are publish... | the berkeley sample of type ii supernovae: bvri light curves and spectroscopy of 55 sne ii |
context. the shape of the ionising spectra of galaxies is a key ingredient to reveal their physical properties and for our understanding of the ionising background radiation. a long-standing unsolved problem is the presence of he ii nebular emission in many low-metallicity star-forming galaxies. this emission requires ... | can nebular he ii emission be explained by ultra-luminous x-ray sources? |
there are many mechanisms by which galaxies can transform from blue, star-forming spirals, to red, quiescent early-type galaxies, but our current census of them does not form a complete picture. recent observations of nearby case studies have identified a population of galaxies that quench “quietly.” traditional postst... | shocked poststarbust galaxy survey. i. candidate post-starbust galaxies with emission line ratios consistent with shocks |
evidence for the capture of nebular gases by planetary interiors would place important constraints on models of planet formation. these constraints include accretion timescales, thermal evolution, volatile compositions and planetary redox states1-7. retention of nebular gases by planetary interiors also constrains the ... | capture of nebular gases during earth's accretion is preserved in deep-mantle neon |
giant planets are thought to have cores in their deep interiors, and the division into a heavy-element core and hydrogen-helium envelope is applied in both formation and structure models. we show that the primordial internal structure depends on the planetary growth rate, in particular, the ratio of heavy elements accr... | the fuzziness of giant planets’ cores |
aims: we aim to characterize the multiwavelength emission from markarian 501 (mrk 501), quantify the energy-dependent variability, study the potential multiband correlations, and describe the temporal evolution of the broadband emission within leptonic theoretical scenarios.methods: we organized a multiwavelength campa... | extreme hbl behavior of markarian 501 during 2012 |
the lack of unambiguous detections of atomic features in the x-ray spectra of ultraluminous x-ray sources (ulxs) has proven a hindrance in diagnosing the nature of the accretion flow. the possible association of spectral residuals at soft energies with atomic features seen in absorption and/or emission and potentially ... | diagnosing the accretion flow in ultraluminous x-ray sources using soft x-ray atomic features |
new integral field spectroscopy has been obtained for izw 18, the nearby lowest-metallicity galaxy considered to be our best local analog of systems forming at high redshift (z). here we report the spatially resolved spectral map of the nebular he ii λ4686 emission in izw 18, from which we derived for the first time it... | the extended he ii λ4686-emitting region in izw 18 unveiled: clues for peculiar ionizing sources |
the mammoth-grism slitless spectroscopic survey is a hubble space telescope (hst) cycle 28 medium program, which is obtaining 45 orbits of wfc3/ir grism spectroscopy in the density peak regions of three massive galaxy protoclusters at z = 2-3 discovered using the mammoth technique. we introduce this survey by presentin... | the mass-metallicity relation at cosmic noon in overdense environments: first results from the mammoth-grism hst slitless spectroscopic survey |
in a companion work (paper i), we detected a large population of highly variable young stellar objects (ysos) in the vista variables in the via lactea (vvv) survey, typically with class i or flat spectrum spectral energy distributions and diverse light-curve types. here we present infrared spectra (0.9-2.5 μm) of 37 of... | infrared spectroscopy of eruptive variable protostars from vvv |
we present nebular phase optical and near-infrared spectroscopy of the type ia supernova (sn) 2017cbv. the early light curves of sn 2017cbv showed a prominent blue bump in the u, b, and g bands lasting for ∼5 days. one interpretation of the early light curve is that the excess blue light is due to shocking of the sn ej... | nebular spectroscopy of the “blue bump” type ia supernova 2017cbv |
we present results on the emission-line properties of 1.3 ≤ z ≤ 2.7 galaxies drawn from the complete the mosfire deep evolution field (mosdef) survey. specifically, we use observations of the emission-line diagnostic diagram of [o iii]λ 5007/hβ versus [s ii]λλ6717,6731/hα, i.e., the “[s ii] bpt diagram,” to gain insigh... | the mosdef survey: sulfur emission-line ratios provide new insights into evolving interstellar medium conditions at high redshift |
determining the origin of volatiles on terrestrial planets and quantifying atmospheric loss during planet formation is crucial for understanding the history and evolution of planetary atmospheres. using geochemical observations of noble gases and major volatiles we determine what the present day inventory of volatiles ... | atmosphere impact losses |
carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur (chnops) play key roles in the origin and proliferation of life on earth. given the universality of physics and chemistry, not least the ubiquity of water as a solvent and carbon as a backbone of complex molecules, chnops are likely crucial to most habitable wor... | chemical habitability: supply and retention of life's essential elements during planet formation |
we study the broadband emission of mrk 501 using multiwavelength observations from 2017 to 2020 performed with a multitude of instruments, involving, among others, magic, fermi's large area telescope (lat), nustar, swift, gasp-webt, and the owens valley radio observatory. mrk 501 showed an extremely low broadband activ... | multimessenger characterization of markarian 501 during historically low x-ray and γ-ray activity |
we report on our study of the supernova (sn) 2022xxf based on observations obtained during the first four months of its evolution. the light curves (lcs) display two humps of similar maximum brightness separated by 75 days, unprecedented for a broad-lined (bl) type ic supernova (sn icbl). sn 2022xxf is the most nearby ... | the broad-lined type-ic supernova sn 2022xxf and its extraordinary two-humped light curves. i. signatures of h/he-free interaction in the first four months |
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