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applying dendrogram analysis to the carma-nro c18o (j = 1-0) data having an angular resolution of ∼8″, we identified 692 dense cores in the orion nebula cluster region. using this core sample, we compare the core and initial stellar mass functions in the same area to quantify the step from cores to stars. about 22% of ... | the core mass function in the orion nebula cluster region: what determines the final stellar masses? |
context. the fate of a massive star during the latest stages of its evolution is highly dependent on its mass-loss rate and geometry and therefore knowing the geometry of the circumstellar material close to the star and its surroundings is crucial.aims: we aim to provide insight into the nature (i.e. geometry, rates) o... | optical and near-infrared observations of the fried egg nebula. multiple shell ejections on a 100 yr timescale from a massive yellow hypergiant |
eight planetary nebulae have been identified as 'born-again', a class of object typified by knotty secondary ejecta having low masses (${\sim}10^{-4}$ m⊙) with nearly no hydrogen. abell 30, the archetype of the class, also belongs to a small subset of planetary nebulae that exhibit extreme abundance discrepancy factors... | abell 30 - a binary central star among the born-again planetary nebulae |
we present a study of 323 photometrically variable young stellar objects that are likely members of the north america and pelican nebulae star-forming region. to do so, we utilize over two years of data in the g and r photometric bands from the zwicky transient facility. we first investigate periodic variability, findi... | a zwicky transient facility look at optical variability of young stellar objects in the north america and pelican nebulae complex |
we have conducted laboratory experiments with analog crystalline silicon carbide (sic) grains using transmission electron microscopy (tem) and electron energy-loss spectroscopy (eels). the 3c polytype of sic was used—the type commonly produced in the envelopes of asymptotic giant branch (agb) stars. we rapidly heated s... | formation of interstellar c60 from silicon carbide circumstellar grains |
pulsar wind nebulae (pwne) are outstanding accelerators in nature, in the sense that they accelerate electrons up to the radiation reaction limit. motivated by this observation, this paper examines the possibility that young pulsar wind nebulae can accelerate ions to ultra-high energies at the termination shock of the ... | on ultra-high energy cosmic ray acceleration at the termination shock of young pulsar winds |
aims: the nonthermal radiative properties of 18 pulsar wind nebulae (pwne) are studied in the 1d leptonic model.methods: the dynamical and radiative evolution of a pwn in a nonradiative supernova remnant are self-consistently investigated in this model. the leptons (electrons/positrons) are injected with a broken power... | multiband nonthermal radiative properties of pulsar wind nebulae |
stellar shells around galaxies could provide precious insights into their assembly history. however, their formation mechanism remains poorly empirically constrained, regarding in particular the type of galaxy collisions at their origin. we present muse at vlt data of the most prominent outer shell of ngc 474, to const... | shedding light on the formation mechanism of shell galaxy ngc 474 with muse |
though the low-ionization small-scale structures (liss) such as knots, filaments and jets of planetary nebulae (pne) are known for ∼30 yr, some of their observational properties are not well established. in consequence, our ability to include them in the wider context of the formation and evolution of pne is directly a... | low-ionization structures in planetary nebulae - i. physical, kinematic and excitation properties |
we report on the mineralogy, petrography, and o-isotope compositions of ∼60 ca, al-rich inclusions (cais) incompletely melted during formation of porphyritic chondrules from the ch metal-rich carbonaceous chondrites and isheyevo (ch/cb). these include (i) relict polymineralic cais in porphyritic chondrules, (ii) cais s... | calcium-aluminum-rich inclusions recycled during formation of porphyritic chondrules from ch carbonaceous chondrites |
we aim at investigating whether the chemical composition of the outer region of the protosolar nebula can be consistent with current estimates of the elemental abundances in the ice giants. to do so, we use a self-consistent evolutionary disc and transport model to investigate the time and radial distributions of h2o, ... | the role of ice lines in the formation of uranus and neptune |
since sep. 2018, lamost has started the medium-resolution (r ~ 7500) spectral survey (mrs). we proposed the spectral survey of galactic nebulae, including h ii regions, hh objects, supernova remnants, planetary nebulae and the special stars with mrs (lamost mrs-n). lamost mrs-n covers about 1700 square degrees of the n... | lamost medium-resolution spectral survey of galactic nebulae (lamost mrs-n): an overview of scientific goals and survey plan |
we present an analysis to disentangle the connection between physical quantities that characterize the conditions of ionized h ii regions - metallicity (z), ionization parameter (u), and electron density (ne) - and the global stellar mass (m*) and specific star formation rate (ssfr = sfr/m*) of the host galaxies. we co... | disentangling the physical parameters of gaseous nebulae and galaxies |
psr j1509-5850 is a middle-aged pulsar with a period of p ≈ 89 ms and spin-down power of \dot{e}=5.1× {10}35 erg s-1, at a distance of about 3.8 kpc. we report on deep chandra x-ray observatory observations of this pulsar and its pulsar wind nebula (pwn). in addition to the previously detected tail extending up to 7‧ s... | chandra observations of outflows from psr j1509-5850 |
we develop a model of gamma-ray flares of the crab nebula resulting from the magnetic reconnection events in a highly magnetised relativistic plasma. we first discuss physical parameters of the crab nebula and review the theory of pulsar winds and termination shocks. we also review the principle points of particle acce... | particle acceleration in explosive relativistic reconnection events and crab nebula gamma-ray flares |
we use the gas-grain chemistry code uclchem to explore the impact of cosmic-ray feedback on the chemistry of circumstellar disks. we model the attenuation and energy losses of the cosmic rays as they propagate outward from the star and also consider ionization due to stellar radiation and radionuclides. for accretion r... | impact of cosmic-ray feedback on accretion and chemistry in circumstellar disks |
deuterium-to-hydrogen (d/h) enrichments in molecular species provide clues about their original formation environment. the organic materials in primitive solar system bodies generally have higher d/h ratios and show greater d/h variation when compared to d/h in solar system water. we propose this difference arises at l... | exploring the origins of deuterium enrichments in solar nebular organics |
using deep multi-wavelength photometry of galaxies from zfourge, we group galaxies at 2.5< z< 4.0 by the shape of their spectral energy distributions (seds). we identify a population of galaxies with excess emission in the ks -band, which corresponds to [o iii]+hβ emission at 2.95< z< 3.65. this population ... | discovery of extreme [o iii]+hβ emitting galaxies tracing an overdensity at z ∼ 3.5 in cdf-south |
context. micro-physical processes on interstellar dust surfaces are tightly connected to dust properties (i.e. dust composition, size, and shape) and play a key role in numerous phenomena in the interstellar medium (ism). the large disparity in physical conditions (i.e. density and gas temperature) in the ism triggers ... | dust evolution across the horsehead nebula |
green peas (gps) are a class of extreme star-forming galaxies (sfgs) at intermediate redshifts, originally discovered via color selection using multifilter, wide-field survey imaging data. they are commonly thought of as being analogs of high-redshift lyα-emitting galaxies. the defining characteristic of gp galaxies is... | properties of the kiss green pea galaxies |
the shaping of various morphological features of planetary nebulae is increasingly linked to the role of binary central stars. identifying a binary within a planetary nebula offers a powerful tool with which to directly investigate the formation mechanisms behind these features. the etched hourglass nebula, mycn 18, is... | salt hrs discovery of the binary nucleus of the etched hourglass nebula mycn 18 |
bow shock pulsar wind nebulae (bspwne) are known to show a large variety of shapes and morphologies, both when comparing different objects, and for the same object in different energy bands. it is unclear if such a variety is related to differences in the pulsar wind properties, or to differences in the conditions of t... | full-3d relativistic mhd simulations of bow shock pulsar wind nebulae: dynamics |
many processes within galaxy clusters, such as those believed to govern the onset of thermally unstable cooling and active galactic nucleus feedback, are dependent upon local dynamical timescales. however, accurate mapping of the mass distribution within individual clusters is challenging, particularly toward cluster c... | mass distribution in galaxy cluster cores |
we present a study of stellar populations in a sample of spectroscopically confirmed lyman-break galaxies (lbgs) and lyα emitters (laes) at 5.7< z< 7. these galaxies have deep images from subaru, the hubble space telescope, and spitzer/irac. we focus on 27 galaxies with irac detections, and characterize their ste... | physical properties of spectroscopically confirmed galaxies at z ≥ 6. iii. stellar populations from sed modeling with secure lyα emission and redshifts |
we investigate a novel bayesian analysis method, based on the stochastically lighting up galaxies (slug) code, to derive the masses, ages, and extinctions of star clusters from integrated light photometry. unlike many analysis methods, slug correctly accounts for incomplete initial mass function (imf) sampling, and ret... | star cluster properties in two legus galaxies computed with stochastic stellar population synthesis models |
we use the large cosmological hydro-dynamic simulation bluetides to predict the photometric properties of galaxies during the epoch of reionization (z = 8-15). these properties include the rest-frame uv to near-ir broad-band spectral energy distributions, the lyman continuum (lyc) photon production, the uv star formati... | the photometric properties of galaxies in the early universe |
we present an analysis of multi-wavelength observations from various data sets and galactic plane surveys to study the star-formation process in the w42 complex. a bipolar appearance of the w42 complex is evident due to the ionizing feedback from the o5-o6 type star in a medium that is highly inhomogeneous. the very la... | the physical environment of the massive star-forming region w42 |
elemental abundance patterns in the galactic disk constrain theories of the formation and evolution of the milky way. h ii region abundances are the result of billions of years of chemical evolution. we made radio recombination line and continuum measurements of 21 h ii regions located between galactic azimuth az = 90°... | azimuthal metallicity structure in the milky way disk |
the gum nebula is 36°-wide shell-like emission nebula at a distance of only ∼450 pc. it has been hypothesized to be an old supernova remnant, fossil h ii region, wind-blown bubble, or combination of multiple objects. here we investigate the magneto-ionic properties of the nebula using data from recent surveys: radio-co... | a radio-polarisation and rotation measure study of the gum nebula and its environment |
the stellar population of the milky way bulge is thoroughly studied, with a plethora of measurements from virtually the full suite of instruments available to astronomers. it is thus perhaps surprising that alongside well-established results lies some substantial uncertainty in its star-formation history. cosmological ... | the controversial star-formation history and helium enrichment of the milky way bulge |
second only to initial mass, the rate of wind-driven mass loss determines the final mass of a massive star and the nature of its remnant. motivated by the need to reconcile observational values and theory, we use a recently vetted technique to analyze the mass-loss rates in a sample of ob stars that generate bow shock ... | mass-loss rates for o and early b stars powering bow shock nebulae: evidence for bistability behavior |
the relative abundance of deuterium and hydrogen is a potent tracer of planet formation and evolution. jupiter and saturn have protosolar atmospheric d/h ratios, a relic of substantial gas accretion from the nebula, while the atmospheres of neptune and uranus are enhanced in d by accretion of ices into their envelopes.... | measuring the d/h ratios of exoplanets and brown dwarfs |
due to the small amount of hydrogen (≤0.1 m ⊙) remaining on the surface of their progenitors, sne iib are sensitive probes of the mass-loss processes of massive stars toward the ends of their lives, including the role of binarity. we report late-time hubble space telescope observations of sn 2011dh in m51, and a brief ... | the origin of the late-time luminosity of supernova 2011dh |
we have carried out a new photometric v,rcstudy of 12 protoplanetary nebulae, objects in the short-lived transition between the asymptotic giant branch and planetary nebula phases of stellar evolution. these had been the subjects of an earlier study, using data from 1994-2007, that found that all 12 varied periodically... | variability in protoplanetary nebulae. ix. evidence for evolution in a decade |
we report on the variability of a multi-component broad absorption line (bal) system observed in the hyper-luminous quasar j1538+0855 at z = 3.6. observations from the sloan digital sky survey (sdss), very large telescope (vlt), large binocular telescope (lbt), and subaru telescope taken at five different epochs, spann... | the wissh quasars project. x. discovery of a multi-component and highly variable uv ultra-fast outflow in a z = 3.6 quasar |
if high-mass stars (≳20 − 25 m⊙) are the progenitors of stripped-envelope (se) supernovae (sne), their massive ejecta should lead to broad, long-duration lightcurves. instead, literature samples of se sne have reported relatively narrow lightcurves corresponding to ejecta masses between 1 − 4 m⊙ that favor intermediate... | a population of type ibc supernovae with massive progenitors. broad lightcurves not uncommon in (i)ptf |
the resonantly scattered lyα line illuminates the extended halos of neutral hydrogen in the circumgalactic medium of galaxies. we present integral field keck cosmic web imager observations of double-peaked, spatially extended lyα emission in 12 relatively low-mass (m ⋆ ~ 109 m⊙) z ~ 2 galaxies characterized by extreme ... | the circumgalactic medium of extreme emission line galaxies at z 2: resolved spectroscopy and radiative transfer modeling of spatially extended lyα emission in the kbss-kcwi survey |
fluffy type a ca-al-rich inclusions (cais) containing reversely zoned melilite crystals are suggested to be aggregates of direct condensates from solar nebular gas. we conducted an investigation of 26al-26mg systematics of a fluffy type a cai from vigarano, named v2-01, with known oxygen isotopic distributions of rever... | chronological study of oxygen isotope composition for the solar protoplanetary disk recorded in a fluffy type a cai from vigarano |
the sagittarius b2 (sgr b2) molecular cloud complex is an x-ray reflection nebula whose nonthermal x-ray emissions have continued to decrease since 2001 as it reprocesses one or more past energetic outbursts from the supermassive black hole sagittarius a* at the galactic center. the x-ray reflection model explains the ... | new constraints on cosmic particle populations at the galactic center using x-ray observations of the molecular cloud sagittarius b2 |
we investigate the physical conditions of the co gas, based on the submillimeter imaging spectroscopy from a 2' × 7' (1.5 × 5 pc2) area near the young star cluster, trumpler 14 of the carina nebula. the observations presented in this work are taken with the fourier transform spectrometer (fts) of the spectral and photo... | constraining physical conditions for the pdr of trumpler 14 in the carina nebula |
the mgro j2019+37 region is one of the brightest sources in the sky at tev energies. it was detected in the second hawc catalog as 2hwc j2019+367 and here we present a detailed study of this region using data from hawc. this analysis resolves the region into two sources: hawc j2019+368 and hawc j2016+371. we associate ... | spectrum and morphology of the very-high-energy source hawc j2019+368 |
while chandrasekhar-mass (mch) models with a low 56ni yield can match the peak luminosities of fast-declining, 91bg-like type ia supernovae (sne ia), they systematically fail to reproduce their faster light-curve evolution. here, we illustrate the impact of a low ejecta mass on the radiative display of low-luminosity s... | the detonation of a sub-chandrasekhar-mass white dwarf at the origin of the low-luminosity type ia supernova 1999by |
we calculate dust spectral energy distributions (seds) for a range of grain sizes and compositions, using physical properties appropriate for five pulsar wind nebulae (pwne) from which dust emission associated with the ejecta has been detected. by fitting the observed dust sed with our models, with the number of grains... | dust masses and grain size distributions of a sample of galactic pulsar wind nebulae |
we study the hydrodynamics and nucleosynthesis in the double-detonation model of type ia supernovae (sne ia) and the interaction between the ejecta and a surviving white dwarf (wd) companion in the double-degenerate scenario. we set up a binary star system with 1.0 and 0.6 m ⊙ carbon-oxygen (co) wds, where the primary ... | three-dimensional simulation of double detonations in the double-degenerate model for type ia supernovae and interaction of ejecta with a surviving white dwarf companion |
data augmentation (da) has emerged as an indispensable strategy in time series classification (tsc), primarily due to its capacity to amplify training samples, thereby bolstering model robustness, diversifying datasets, and curtailing overfitting. however, the current landscape of da in tsc is plagued with fragmented l... | data augmentation for time-series classification: an extensive empirical study and comprehensive survey |
approximately one hundred sources of very-high-energy (vhe) gamma rays are known in the milky way. a survey of the entire galactic plane in the energy range from a few tens of gev to a few hundred tev has been proposed as a key science project for the upcoming cherenkov telescope array observatory (ctao). this article ... | prospects for a survey of the galactic plane with the cherenkov telescope array |
i examine the morphologies of the brightest planetary nebulae (pne) in the milky way galaxy and conclude that violent binary interaction processes eject the main nebulae of the brightest pne. the typical morphologies of the brightest pne are multipolar, namely have been shaped by two or more major jet-launching episode... | violent mass ejection by the progenitors of the brightest planetary nebulae: supernova progenitors |
the entire southern sky (declination, $δ< 30^{\circ}$ ) has been observed using the murchison widefield array (mwa), which provides radio imaging of $∼$ 2 arcmin resolution at low frequencies (72-231 mhz). this is the galactic and extragalactic all-sky mwa (gleam) survey, and we have previously used a combination of... | the gleam 4-jy (g4jy) sample: ii. host galaxy identification for individual sources |
as a candidate `super-chandrasekhar' or 09dc-like type ia supernova (sn ia), sn 2012dn shares many characteristics with other members of this remarkable class of objects but lacks their extraordinary luminosity. here, we present and discuss the most comprehensive optical data set of this sn to date, comprised of a dens... | sn 2012dn from early to late times: 09dc-like supernovae reassessed |
we present new estimates of protosolar elemental abundances based on an improved combination of solar photospheric abundances and ci chondritic abundances. these new estimates indicate ci chondrites and solar abundances are consistent for 60 elements. our estimate of the protosolar "metallicity" (i.e. mass fraction of ... | the volatility trend of protosolar and terrestrial elemental abundances |
this work presents the observations and analysis of atlas19dqr/sn 2019bkc, an extraordinary rapidly evolving transient event located in an isolated environment, tens of kiloparsecs from any likely host. its light curves rise to maximum light in 5-6 d and then display a decline of δm15 ∼ 5 mag. with such a pronounced de... | the rise and fall of an extraordinary ca-rich transient. the discovery of atlas19dqr/sn 2019bkc |
cross-correlation techniques have been used since 1974 and, since 1979, the analysis based on the fourier method has been applied. however, we are currently obtaining data with spectral resolution higher than those for which this technique was developed, hence some revision seems timely. the principal aim of this work ... | revising the cross correlation technique at high spectral resolution |
models of core accretion assume that in the radiative zones of accreting gas envelopes, radiation diffuses. but super-earths/sub-neptunes (1-4 r⊕, 2-20 m⊕) point to formation conditions that are optically thin: their modest gas masses are accreted from short-lived and gas-poor nebulae reminiscent of the transparent cav... | optically thin core accretion: how planets get their gas in nearly gas-free discs |
we investigate pathways for the formation of icy super-earth mass planets orbiting at 125-250 au around a 1 {{m}⊙ } star. an extensive suite of coagulation calculations demonstrates that swarms of 1 cm-10 m planetesimals can form super-earth mass planets on timescales of 1-3 gyr. collisional damping of 10-2-102 cm part... | formation of super-earth mass planets at 125-250 au from a solar-type star |
planetary nebulae mark the end of the active life of 90% of all stars. they trace the transition from a red giant to a degenerate white dwarf. stellar models1,2 predicted that only stars above approximately twice the solar mass could form a bright nebula. but the ubiquitous presence of bright planetary nebulae in old s... | the mysterious age invariance of the planetary nebula luminosity function bright cut-off |
we present a catalog of 840 x-ray sources and first results from a 100 ks chandra x-ray observatory imaging study of the filamentary infrared (ir) dark cloud g014.225-00.506, which forms the central regions of a larger cloud complex known as the m17 southwest extension (m17 swex). in addition to the rich population of ... | rapid circumstellar disk evolution and an accelerating star formation rate in the infrared dark cloud m17 swex |
type ia sn 2014j exploded in the nearby starburst galaxy m82 = ngc 3032 and was discovered at earth about seven days later on 2014 january 21, reaching maximum light in v around 2014 february 5. sn 2014j is the closest sn ia in at least four decades and probably many more. recent hubble space telescope/wfc3 imaging (20... | light echoes from supernova 2014j in m82 |
we present a near-ir survey of the trapezium cluster and inner orion nebula using the nasa/esa/csa james webb space telescope. the survey with the nircam instrument covers 10.9 x 7.5 arcminutes (~1.25 x 0.85 pc) in twelve wide-, medium-, and narrow-band filters from 1-5 microns and is diffraction-limited at all wavelen... | a jwst survey of the trapezium cluster & inner orion nebula. i. observations & overview |
hess j1825-137 is a pulsar wind nebula (pwn) whose tev emission extends across ∼1 . its large asymmetric shape indicates that its progenitor supernova interacted with a molecular cloud located in the north of the pwn as detected by previous co galactic survey (e.g. lemiere, terrier & djannati-ataï). here, we provid... | ism gas studies towards the tev pwn hess j1825-137 and northern region |
we present the results of 3d particle-in-cell simulations that explore relativistic magnetic reconnection in pair plasma with strong synchrotron cooling and a small mass fraction of nonradiating ions. our results demonstrate that the structure of the current sheet is highly sensitive to the dynamic efficiency of radiat... | high-energy radiation and ion acceleration in three-dimensional relativistic magnetic reconnection with strong synchrotron cooling |
the recent detection of the geminga pulsar wind nebula (pwn) by hawc in the multi-tev band allows us to infer precious information about the transport of pairs in the immediate surroundings of the pulsar and on the spectrum of pairs contributed by a geminga-like pulsar to the spectrum of pairs in the cosmic radiation. ... | tev halos and the role of pulsar wind nebulae as sources of cosmic-ray positrons |
we perform numerical simulations to investigate the stellar wind from interacting binary stars. our aim is to find analytical formulae describing the outflow structure. in each binary system the more massive star is in the asymptotic giant branch (agb) and its wind is driven by a combination of pulsations in the stella... | agb winds in interacting binary stars |
the bubble nebula (or ngc 7635) is a parsec-scale seemingly spherical wind-blown bubble around the relatively unevolved o star bd+60°2522. the young dynamical age of the nebula and significant space velocity of the star suggest that the bubble nebula might be a bow shock. we ran 2d hydrodynamic simulations to model the... | thermal emission from bow shocks. i. 2d hydrodynamic models of the bubble nebula |
we present a synthetic galaxy lightcone specially designed for narrow-band optical photometric surveys. to reduce time-discreteness effects, unlike previous works, we directly include the lightcone construction in the l-galaxies semi-analytic model applied to the subhalo merger trees of the millennium simulation. addit... | j-plus: synthetic galaxy catalogues with emission lines for photometric surveys |
one clear observational prediction of the single-degenerate progenitor scenario as the origin of type ia supernovae (sne) is the presence of relatively narrow (≈1000 km s-1) hα emission at nebular phases, although this feature is rarely seen. we present a compilation of nebular phase hα limits for sn ia in the literatu... | nebular hα limits for fast declining sne ia |
bow shock pulsar wind nebulae are observed with a variety of complex morphologies at different wavelengths, most likely due to differences in the magnetic field strength and pulsar wind geometry. here we present a detailed analysis, showing how these differences affect the observational properties in these systems, foc... | full-3d relativistic mhd simulations of bow shock pulsar wind nebulae: emission and polarization |
lyman-α blobs (labs) are spatially extended nebulae of emission in the lyman-α (lyα) line of hydrogen, seen at high redshifts1,2, and most commonly found in the dense environment of star-forming galaxies3,4. a recent study showed that nearly 100% of the sky is covered by lyα emission around high-redshift galaxies5-7. t... | infalling gas in a lyman-α blob |
context. there is a class of binary post-agb stars with a remarkable near-infrared excess that are surrounded by keplerian or quasi-keplerian disks and extended outflows composed of gas escaping from the disk. the keplerian dynamics had been well identified in four cases, namely the red rectangle, ac her, iw car, and i... | keplerian disks and outflows in post-agb stars: ac herculis, 89 herculis, iras 19125+0343, and r scuti |
fast-rotating pulsars and magnetars have been suggested as the central engines of superluminous supernovae (slsne) and fast radio bursts, and this scenario naturally predicts non-thermal synchrotron emission from their nascent pulsar wind nebulae (pwne). we report results of high-frequency radio observations with alma ... | alma and noema constraints on synchrotron nebular emission from embryonic superluminous supernova remnants and radio-gamma-ray connection |
radiation-dust driven outflows, where radiation pressure on dust grains accelerates gas, occur in many astrophysical environments. almost all previous numerical studies of these systems have assumed that the dust was perfectly coupled to the gas. however, it has recently been shown that the dust in these systems is uns... | dust in the wind with resonant drag instabilities - i. the dynamics of dust-driven outflows in gmcs and h ii regions |
context. m 105 (ngc 3379) is an early-type galaxy in the nearby leo i group, the closest galaxy group to contain all galaxy types and therefore an excellent environment to explore the low-mass end of intra-group light (igl) assembly.aims: we present a new and extended kinematic survey of planetary nebulae (pne) in m 10... | the halo of m 105 and its group environment as traced by planetary nebula populations. ii. using kinematics of single stars to unveil the presence of intragroup light around the leo i galaxies ngc 3384 and m 105 |
we use the hubble space telescope advanced camera for surveys to obtain the first spatially resolved, nebular imaging in the light of c iv λ λ1548, 1551 by using the f150lp and f165lp filters. these observations of the local starburst mrk 71 in ngc 2366 show emission apparently originating within the interior cavity ar... | nebular c iv λ1550 imaging of the metal-poor starburst mrk 71: direct evidence of catastrophic cooling |
we present evidence in support of the hypothesis that the young stellar object rno 54 is a mature-stage fu ori type source. the star was first cataloged as a "red nebulous object" in the 1980s but appears to have undergone its outburst prior to the 1890s. present-day optical and near-infrared spectra are consistent wit... | rno 54: a previously unappreciated fu ori star |
we summarize the results of a spectropolarimetric survey of 56 chemically peculiar (cp) stars in the association of orion ob1. we uniformly collected the observational material with the 6-m telescope bta of the special astrophysical observatory in 2013-2021. we identify 14 new magnetic cp stars with a longitudinal magn... | spectropolarimetry of magnetic chemically peculiar stars in the orion ob1 association |
here we describe a new study of the supernova remnants (snrs) and snr candidates in nearby face-on spiral galaxy m83, based primarily on muse integral field spectroscopy. our revised catalog of snr candidates in m83 has 366 objects, 81 of which are reported here for the first time. of these, 229 lie within the muse obs... | supernova remnants in m83 as observed with muse |
the javalambre-physics of the accelerating universe astrophysical survey (j-pas) is a photometric survey that is poised to scan several thousands of square degrees of the sky. it will use 54 narrow-band filters, combining the benefits of low-resolution spectra and photometry. its offshoot, minijpas, is a 1 deg2 survey ... | the minijpas survey. galaxy populations in the most massive cluster in minijpas: mjpc2470-1771 |
i use recent observations of circumstellar matter (csm) around type ia supernovae (sne ia) to estimate the fraction of sne ia that explode into a planetary nebula (pn) and to suggest a new delay time distribution from the common envelope evolution (cee) to the sn ia explosion for sne ia that occur shortly after the cee... | common envelope to explosion delay time distribution (ceedtd) of type ia supernovae |
we present and publicly release a new star-forming regions emission library toddlers (time evolution of observables including dust diagnostics and line emission from regions containing young stars) for the publicly available radiative transfer code skirt. the library generation involves the spherical evolution of a hom... | toddlers: a new uv-mm emission library for star-forming regions - i. integration with skirt and public release |
the [o iii] 5007 å line is typically the brightest line in planetary nebula (pn) spectra. observations show that the brightest [o iii] 5007 å pn in a galaxy-the planetary nebula luminosity function (pnlf) bright-end cutoff-is surprisingly independent of galaxy type. to understand the origin of this puzzling uniformity,... | the origin of the consistent planetary nebula luminosity function bright-end cutoff |
turbulent motions in the circumgalactic medium (cgm) play a critical role in regulating the evolution of galaxies, yet their detailed characterization remains elusive. using two-dimensional velocity maps constructed from spatially-extended [oii] and [oiii] emission, chen et al. (2023b) measured the velocity structure f... | an ensemble study of turbulence in extended qso nebulae at $z\\approx0.5$--1 |
a family of unidentified infrared emission (uie) bands has been observed throughout the universe. the current observed spectral properties of the uie bands are summarized. these properties are discussed in the frameworks of different models of the chemical carriers of these bands. the uie carriers represent a large res... | the mystery of unidentified infrared emission bands |
we present a detailed theoretical study of the rotational excitation of ch+ due to reactive and non-reactive collisions involving c+(2p), h2, ch+, h and free electrons. specifically, the formation of ch+ proceeds through the reaction between c+(2p) and h_2(ν _h_2 = 1, 2), while the collisional (de)excitation and destru... | state-to-state chemistry and rotational excitation of ch+ in photon-dominated regions |
context. measurements of internal dynamics of young clusters and star-forming regions are crucial to fully understand the process of their formation. a basic prerequisite for this is a well-established and robust list of probable members.aims: in this work, we study the 2.8° ×2.6° region in the emblematic rosette nebul... | stellar population of the rosette nebula and ngc 2244. application of the probabilistic random forest |
the spread of invasive species continues to reduce biodiversity across all regions and habitat types globally. however, invader impact prediction can be nebulous, and approaches often fail to integrate coupled direct and indirect invader effects. here, we examine the ecological impacts of an invasive higher predator on... | intermediate predator naïveté and sex-skewed vulnerability predict the impact of an invasive higher predator |
we present the results of a study of the accretion rate of planetesimals by a growing proto-jupiter in the core-accretion model. the purpose of our study is to test the assumptions of pollack et al. regarding the flux of planetesimals and their encounter velocities with the protoplanet. using a newly developed code, we... | detailed calculations of the efficiency of planetesimal accretion in the core-accretion model |
radiometric dating indicates that mars accreted in the first ~4 myr of the solar system, coinciding with the formation and possible migration of jupiter. while nebular gas from the protoplanetary disk was still present, jupiter may have migrated inward and tacked at 1.5 au in a 3:2 resonance with saturn. this migration... | jupiter's influence on the building blocks of mars and earth |
to date, over 220 emission nebulae in m33 have been identified as supernova remnants (snrs) or snr candidates, principally through [s ii]:hα line ratios that are elevated compared to those in h ii regions. in many cases, the determination of a high [s ii]:hα line ratio was made using narrow-band interference filter ima... | mmt spectroscopy of supernova remnant candidates in m33 |
using 3d radiation-hydrodynamic simulations and analytic theory, we study the orbital evolution of asymptotic giant branch (agb) binary systems for various initial orbital separations and mass ratios, and thus different initial accretion modes. the time evolution of binary separations and orbital periods are calculated... | wind-accelerated orbital evolution in binary systems with giant stars |
we present near-infrared (nir) spectroscopy of the nearby supernova 2014j obtained ∼450 d after explosion. we detect the [ni ii] 1.939 μm line in the spectra indicating the presence of stable 58ni in the ejecta. the stable nickel is not centrally concentrated but rather distributed as the iron. the spectra are dominate... | nebular spectroscopy of sn 2014j: detection of stable nickel in near-infrared spectra |
calcium-aluminum-rich inclusions (cais) and amoeboid olivine aggregates (aoas), a refractory component of chondritic meteorites, formed in a high-temperature region of the protoplanetary disk characterized by approximately solar chemical and oxygen isotopic (δ17o ∼ -24‰) compositions, most likely near the protosun. her... | first evidence for silica condensation within the solar protoplanetary disk |
context. pulsar wind nebulae are efficient particle accelerators, and yet the processes at work remain elusive. self-generated, microturbulence is too weak in relativistic magnetized shocks to accelerate particles over a wide energy range, suggesting that the global dynamics of the nebula may be involved in the acceler... | a global model of particle acceleration at pulsar wind termination shocks |
some supernova (sn) explosions show evidence for an interaction with a pre-existing nonspherically symmetric circumstellar medium (csm) in their light curves, spectral line profiles, and polarization signatures. the origin of this aspherical csm is unknown, but binary interactions have often been implicated. to better ... | supernova explosions interacting with aspherical circumstellar material: implications for light curves, spectral line profiles, and polarization |
aims: two-dimensional spectroscopic data for the whole extent of the ngc 3132 planetary nebula have been obtained. we deliver a reduced data-cube and high-quality maps on a spaxel-by-spaxel basis for the many emission lines falling within the multi-unit spectroscopic explorer (muse) spectral coverage over a range in su... | the muse view of the planetary nebula ngc 3132 |
we investigate a possible correlation between the solid surface density σ of the minimum-mass extrasolar nebula (mmen) and the host star mass m⋆ and metallicity [fe/h]. leveraging on the precise host star properties from the california-kepler survey (cks), we found that ${\rm{\sigma }}={50}_{-20}^{+33}\,{\rm{g}}\,{\mat... | california-kepler survey. ix. revisiting the minimum-mass extrasolar nebula with precise stellar parameters |
extragalactic planetary nebulae (pne) are detectable through relatively strong nebulous [o iii] emission and act as direct probes into the local stellar population. because they have an apparently universal invariant magnitude cut-off, pne are also considered to be a remarkable standard candle for distance estimation. ... | fornax 3d project: automated detection of planetary nebulae in the centres of early-type galaxies and first results |
in the early, disk-embedded phase of evolution of terrestrial planets, a protoplanetary core can accumulate gas from the circumstellar disk into a planetary envelope. in order to relate the accumulation and structure of this primordial atmosphere to the thermal evolution of the planetary core, we calculated atmosphere ... | dynamical accretion of primordial atmospheres around planets with masses between 0.1 and 5 m ⊕ in the habitable zone |
several decades of observations and discoveries have shown that high-redshift agn and massive galaxies are often surrounded by giant lyα nebulae extending in some cases up to 500 kpc in size. in this chapter, i review the properties of the such nebulae discovered at z > 2 and their connection with gas flows in and a... | gas accretion and giant lyα nebulae |
context. there are a number of methods that identify stellar sub-structure in star forming regions, but these do not quantify the degree of association of individual stars - something which is required if we are to better understand the mechanisms and physical processes that dictate structure.aims: we present the new n... | the spatial evolution of young massive clusters. i. a new tool to quantitatively trace stellar clustering |
we present two epochs of near-infrared spectroscopy of the candidate red supergiant counterpart to rx j004722.4-252051, a ulx in ngc 253. we measure radial velocities of the object and its approximate spectral type by cross-correlating our spectra with those of known red supergiants. our vlt/x-shooter spectrum is best ... | discovery of a red supergiant counterpart to rx j004722.4-252051, a ulx in ngc 253 |
we report high-resolution observations of the 12co(1-0) and 13co(1-0) molecular lines in the carina nebula and the gum 31 region obtained with the 22-m mopra telescope as part of the mopra southern galactic plane co survey. we cover 8 deg2 from l = 285° to 290°, and from b = -1.5° to +0.5°. the molecular gas column den... | the carina nebula and gum 31 molecular complex - i. molecular gas distribution, column densities, and dust temperatures |
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