abstract stringlengths 3 192k | title stringlengths 4 857 |
|---|---|
a scenario for the formation of multiple co-eval populations separated in age by about 1 myr in very young clusters (vycs, ages less than 10 myr) and with masses in the range 600-20 000 m⊙ is outlined. it rests upon a converging inflow of molecular gas building up a first population of pre-main sequence stars. the asso... | evidence for feedback and stellar-dynamically regulated bursty star cluster formation: the case of the orion nebula cluster |
we develop a model of particle acceleration in explosive reconnection events in relativistic magnetically-dominated plasmas and apply it to explain gamma-ray flares from the crab nebula. the model relies on development of current-driven instabilities on macroscopic scales (not related to plasma skin depths). using anal... | particle acceleration in explosive relativistic reconnection events and crab nebula gamma-ray flares |
the emission of supernova remnants (snrs) reflects the properties of both the progenitor supernovae (sne) and the surrounding environment. the complex morphology of the remnants, however, hampers the disentanglement of the two contributions. here, we aim at identifying the imprint of sn 1987a on the x-ray emission of i... | supernova 1987a: a template to link supernovae to their remnants |
context. markarian 501 (mrk 501) is a very high-energy (vhe) gamma-ray blazar located at z = 0.034, which is regularly monitored by a wide range of multi-wavelength instruments, from radio to vhe gamma rays. during a period of almost two weeks in july 2014, the highest x-ray activity of mrk 501 was observed in ∼14 year... | study of the variable broadband emission of markarian 501 during the most extreme swift x-ray activity |
high-energy emission associated with star formation has been proposed as a significant source of interstellar medium (ism) ionization in low-metallicity starbursts and an important contributor to the heating of the intergalactic medium (igm) in the high-redshift (z ≳ 8) universe. using chandra observations of a sample ... | elevated hot gas and high-mass x-ray binary emission in low-metallicity galaxies: implications for nebular ionization and intergalactic medium heating in the early universe |
luminous blue variables are massive evolved stars, here we introduce this outstanding class of objects. described are the specific characteristics, the evolutionary state and what they are connected to other phases and types of massive stars. our current knowledge of lbvs is limited by the fact that in comparison to ot... | luminous blue variables |
we present optical and near-infrared photometric and spectroscopic observations of sn 2013ej, in galaxy m74, from 1 to 450 d after the explosion. sn 2013ej is a hydrogen-rich supernova, classified as a type iil due to its relatively fast decline following the initial peak. it has a relatively high peak luminosity (abso... | 450 d of type ii sn 2013ej in optical and near-infrared |
the recent launch of jwst has enabled the exciting prospect of detecting the first generation of metal-free, population iii (pop. iii) stars. determining characteristics that robustly signify pop. iii stars against other possible contaminants represents a key challenge. to this end, we run high-resolution (sub-pc) cosm... | the challenges of identifying population iii stars in the early universe |
when supernovae enter the nebular phase after a few months, they reveal spectral fingerprints of their deep interiors, glowing by radioactivity produced in the explosion. we are given a unique opportunity to see what an exploded star looks like inside. the line profiles and luminosities encode information about physica... | spectra of supernovae in the nebular phase |
supernova (sn) 2021ocs was discovered in the galaxy ngc 7828 (z = 0.01911) within the interacting system arp 144 and subsequently classified as a normal type ic sn around peak brightness. very large telescope/fors2 observations in the nebular phase at 148 days reveal that the spectrum is dominated by oxygen and magnesi... | late-time h/he-poor circumstellar interaction in the type ic supernova sn 2021ocs: an exposed oxygen-magnesium layer and extreme stripping of the progenitor |
i identify a point-symmetric structure in recently published vlt/muse velocity maps of different elements in a plane along the line of sight at the center of the supernova remnant snr 0540-69.3, and argue that jittering jets that exploded this core collapse supernova shaped this point-symmetric structure. the four pair... | imprints of the jittering jets explosion mechanism in the morphology of the supernova remnant snr 0540-69.3 |
we present a survey for the tightest visual binaries among 0.3-2 m⊙ members of the orion nebula cluster (onc). among 42 targets, we discovered 13 new 0.025-0.15 arcsec companions. accounting for the branch bias, we find a companion star fraction (csf) in the 10-60 au range of 21^{+8}_{-5} per cent, consistent with that... | is stellar multiplicity universal? tight stellar binaries in the orion nebula cluster |
we present the first detection of gas-phase s2h in the horsehead, a moderately uv-irradiated nebula. this confirms the presence of doubly sulfuretted species in the interstellar medium and opens a new challenge for sulfur chemistry. the observed s2h abundance is ∼5 × 10-11, only a factor of 4-6 lower than that of the w... | first detection of interstellar s2h |
we measure the ionizing photon production efficiency (ξion) of low-mass galaxies (107.8-109.8 m⊙) at 1.4 < z < 2.7 to better understand the contribution of dwarf galaxies to the ionizing background and reionization. we target galaxies that are magnified by strong-lensing galaxy clusters and use keck/mosfire to me... | the ionizing photon production efficiency (ξion) of lensed dwarf galaxies at z ∼ 2 |
we present a detailed study of stellar rotation in the massive 1.5 gyr old cluster ngc 1846 in the large magellanic cloud. similar to other clusters at this age, ngc 1846 shows an extended main-sequence turn-off (emsto), and previous photometric studies have suggested it could be bimodal. in this study, we use muse int... | how stellar rotation shapes the colour-magnitude diagram of the massive intermediate-age star cluster ngc 1846 |
context. the carina nebula complex (cnc) is one of the most massive and active star-forming regions in our galaxy and it contains several large young star clusters. the distances of the individual clusters and their physical connection were poorly known up to now, with strongly discrepant results reported in the litera... | gaia edr3 distances of the young stellar clusters in the extended carina nebula complex |
we present the results from deep suzaku observations of the central region of the perseus cluster. bulbul et al. (2014, apj, 789, 13) reported the detection by xmm-newton instruments of an unidentified x-ray emission line at an energy around 3.5 kev in spectra for the perseus and other clusters. they argued for a possi... | an x-ray spectroscopic search for dark matter in the perseus cluster with suzaku |
we present the first reported case of the simultaneous metallicity determination of a gamma-ray burst (grb) host galaxy, from both afterglow absorption lines as well as strong emission-line diagnostics. using spectroscopic and imaging observations of the afterglow and host of the long-duration swift grb 121024a at z = ... | the warm, the excited, and the molecular gas: grb 121024a shining through its star-forming galaxy |
we present multiband ultraviolet, optical, and near-infrared photometry, along with visual-wavelength spectroscopy, of supernova (sn) 2014g in the nearby galaxy ngc 3448 (25 mpc). the early-phase spectra show strong emission lines of the high ionization species he ii/n iv/c iv during the first 2-3 d after explosion, tr... | the multifaceted type ii-l supernova 2014g from pre-maximum to nebular phase |
the star formation histories (sfhs) of dwarf galaxies are thought to be bursty, with large - order of magnitude - changes in the star formation rate on time-scales similar to o-star lifetimes. as a result, the standard interpretations of many galaxy observables (which assume a slowly varying sfh) are often incorrect. h... | consequences of bursty star formation on galaxy observables at high redshifts |
planets with sizes between those of earth and neptune divide into two populations: purely rocky bodies whose atmospheres contribute negligibly to their sizes, and larger gas-enveloped planets possessing voluminous and optically thick atmospheres. we show that whether a planet forms rocky or gas-enveloped depends on the... | a metallicity recipe for rocky planets |
nature's most powerful high-energy sources are capable of accelerating particles to high energy and radiating it away on extremely short timescales, even shorter than the light crossing time of the system. it is yet unclear what physical processes can produce such an efficient acceleration, despite the copious radiativ... | pitch-angle anisotropy controls particle acceleration and cooling in radiative relativistic plasma turbulence |
we study the relation between the chemical composition and the type of dust present in a group of 20 galactic planetary nebulae (pne) that have high-quality optical and infrared spectra. the optical spectra are used, together with the best available ionization correction factors, to calculate the abundances of ar, c, c... | oxygen enrichment in carbon-rich planetary nebulae |
context. our knowledge of the shape of radial metallicity gradients in disc galaxies has recently improved. conversely, the understanding of their time evolution is more complex, since it requires analysis of stellar populations with different ages or systematic studies of galaxies at different redshifts. in the local ... | metallicity gradients in local universe galaxies: time evolution and effects of radial migration |
the guest star of ad 1181 is the only historical supernova of the past millennium that is without a definite counterpart. the previously proposed association with supernova remnant g130.7+3.1 (3c 58) is in strong doubt because of the inferred age of this remnant. here we report a new identification of sn 1181 with our ... | the remnant and origin of the historical supernova 1181 ad |
we present optical photometry and spectroscopy of the type ia supernova sn2018cqj/atlas18qtd. the supernova exploded in an isolated region at ∼65 kpc from the s0 galaxy ic 550 at z = 0.0165 (d ≈ 74 mpc) and has a redshift consistent with a physical association to this galaxy. multicolor photometry show that sn2018cqj/a... | variable hα emission in the nebular spectra of the low-luminosity type ia sn2018cqj/atlas18qtd |
the kinematics and dynamics of young stellar populations enable us to test theories of star formation. with this aim, we continue our analysis of the sdss-iii/apogee in-sync survey, a high-resolution near-infrared spectroscopic survey of young clusters. we focus on the orion a star-forming region, for which in-sync obt... | in-sync. v. stellar kinematics and dynamics in the orion a molecular cloud |
a modified galaxy classification scheme for local galaxies is presented. it builds upon the aitken-jeans nebula sequence, by expanding the jeans-hubble tuning fork diagram, which itself contained key ingredients from curtis and reynolds. the two-dimensional grid of galaxy morphological types presented here, with elemen... | a galaxy classification grid that better recognizes early-type galaxy morphology |
we present high-cadence, comprehensive data on the nearby (d ≃ 33 mpc) type ii supernova (sn ii) 2017ahn, discovered within about one day of the explosion, from the very early phases after explosion to the nebular phase. the observables of sn 2017ahn show a significant evolution over the ≃470 days of our follow-up camp... | the early discovery of sn 2017ahn: signatures of persistent interaction in a fast-declining type ii supernova |
a characteristic feature that is frequently found in nearby supernova remnants (snrs) is the existence of two antisymmetric, local protrusions that are projected as two 'ears' in the morphology of the nebula. in this paper, we present a novel scenario for the 'ear' formation process, according to which the two lobes ar... | 'ears' formation in supernova remnants: overhearing an interaction history with bipolar circumstellar structures |
we report observations and modeling of the stellar remnant and presumed double-degenerate merger of type iax supernova pa 30, which is the probable remnant of sn 1181 ad. it is the only known bound stellar sn remnant and the only star with wolf-rayet features that is neither a planetary nebula central star nor a massiv... | a new study on a type iax stellar remnant and its probable association with sn 1181 |
superluminous supernovae are among the most energetic stellar explosions in the universe, but their energy sources remain an open question. here we present long-term observations of one of the closest examples of the hydrogen-poor superluminous supernovae subclass slsne-i, supernova sn 2017egm, revealing the most compl... | a superluminous supernova lightened by collisions with pulsational pair-instability shells |
gas-giant planets, like jupiter and saturn, acquire massive gaseous envelopes during the approximately 3 myr-long lifetimes of protoplanetary discs. in the core accretion scenario, the formation of a solid core of around ten earth masses triggers a phase of rapid gas accretion. previous 3d grid-based hydrodynamical sim... | quasi-static contraction during runaway gas accretion onto giant planets |
we have produced for the first time a detailed velocity map of the giant filamentary nebula surrounding ngc 1275, the perseus cluster's brightest galaxy, and revealed a previously unknown rich velocity structure across the entire nebula. these new observations were obtained with the optical imaging fourier transform sp... | revealing the velocity structure of the filamentary nebula in ngc 1275 in its entirety |
chondritic meteorites, the building blocks of terrestrial planets, are made of an out-of-equilibrium assemblage of solids formed at high and low temperatures, either in our solar system or previous generations of stars. for decades this was considered to result from large-scale transport processes in the sun’s isolated... | making the planetary material diversity during the early assembling of the solar system |
context.aims: in order to study the effects of rotating disks in the post-asymptotic giant branch (post-agb) evolution, we observe a class of binary post-agb stars that seem to be systematically surrounded by equatorial disks and slow outflows. although the rotating dynamics had only been well identified in three cases... | high-resolution observations of iras 08544-4431. detection of a disk orbiting a post-agb star and of a slow disk wind |
the search for extraterrestrial intelligence (seti) attempts to address the possibility of the presence of technological civilizations beyond the earth. benefiting from high sensitivity, large sky coverage, and an innovative feed cabin for china's five-hundred-meter aperture spherical radio telescope (fast), we perform... | first seti observations with china's five-hundred-meter aperture spherical radio telescope (fast) |
we present optical, ultraviolet, and infrared data of the type ii supernova (sn ii) 2020jfo at 14.5 mpc. this wealth of multiwavelength data allows us to compare different metrics commonly used to estimate progenitor masses of sn ii for the same object. using its early light curve, we infer sn 2020jfo had a progenitor ... | type ii-p supernova progenitor star initial masses and sn 2020jfo: direct detection, light-curve properties, nebular spectroscopy, and local environment |
context. the spectral classifications of the galactic o-star spectroscopic survey (gosss) and the astrometric and photometric data from gaia have significantly improved our ability to measure distances and determine memberships of stellar groups (clusters, associations, or parts thereof) with ob stars. in the near futu... | the villafranca catalog of galactic ob groups. i. systems with o2-o3.5 stars |
lyα emission is widely used to detect and confirm high-redshift galaxies and characterize the evolution of the intergalactic medium (igm). however, many galaxies do not display lyα emission in typical spectroscopic observations, and intrinsic lyα emitters represent a potentially biased set of high-redshift galaxies. in... | predicting lyα emission from galaxies via empirical markers of production and escape in the kbss |
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 |
the contemporaneous detection of gravitational waves and gamma rays from gw170817/grb 170817a, followed by kilonova emission a day after, confirmed compact binary neutron star mergers as progenitors of short-duration gamma-ray bursts (grbs) and cosmic sources of heavy r-process nuclei. however, the nature (and life spa... | a short gamma-ray burst from a protomagnetar remnant |
in galaxy clusters, the hot intracluster medium (icm) can develop a striking multiphase structure around the brightest cluster galaxy. much work has been done on understanding the origin of this central nebula, but less work has studied its eventual fate after the originally filamentary structure is broken into individ... | shattering and growth of cold clouds in galaxy clusters: the role of radiative cooling, magnetic fields, and thermal conduction |
we have investigated the fine-grained matrix of the least-altered unequilibrated ordinary chondrite (uoc) semarkona (ll3.00) using different electron microscope techniques. unlike previous studies, which found that the matrix of semarkona was extensively altered to phyllosilicates, we have discovered the widespread occ... | amorphous silicates in the matrix of semarkona: the first evidence for the localized preservation of pristine matrix materials in the most unequilibrated ordinary chondrites |
when corrected for the effects of cosmic ray exposure, mo and ru nucleosynthetic isotope anomalies in iron meteorites from at least nine different parent bodies are strongly correlated in a manner consistent with variable depletion in s-process nucleosynthetic components. in contrast to prior studies, the new results s... | new insights into mo and ru isotope variation in the nebula and terrestrial planet accretionary genetics |
the c iii] and c iv rest-frame uv emission lines are powerful probes of the ionization states of galaxies. they have furthermore been suggested as alternatives for spectroscopic redshift confirmation of objects at the epoch of reionization (z> 6), where the most frequently used redshift indicator, lyα, is attenuated... | the grism lens-amplified survey from space (glass). xi. detection of c iv in multiple images of the z = 6.11 lyα emitter behind rxc j2248.7-4431 |
context. the class 0 protostellar binary iras 16293-2422 is an interesting target for (sub)millimeter observations due to, both, the rich chemistry toward the two main components of the binary and its complex morphology. its proximity to earth allows the study of its physical and chemical structure on solar system scal... | the alma-pils survey: 3d modeling of the envelope, disks and dust filament of iras 16293-2422 |
we use planetary nebulae (pne) as probes to determine the galactic radial oxygen gradients and other abundance patterns. we select data homogeneously from recent data sets, including pne at large galactocentric distances. the radial oxygen gradient calculated for the general pn population, which probes the region from ... | galactic planetary nebulae as probes of radial metallicity gradients and other abundance patterns |
studies of internal structure of gas giant planets suggest that their envelopes are enriched with heavier elements than hydrogen and helium relative to their central stars. such enrichment likely occurred by solid accretion during late formation stages of gas giant planets in which gas accretion dominates protoplanetar... | capture of solids by growing proto-gas giants: effects of gap formation and supply limited growth |
if very massive stars (m ≳ 100 m⊙) can form and avoid too strong mass-loss during their evolution, they are predicted to explode as pair-instability supernovae (pisne). one critical test for candidate events is whether their nucleosynthesis yields and internal ejecta structure, being revealed through nebular-phase spec... | nebular spectra of pair-instability supernovae |
the planetary nebula stage is the ultimate fate of stars with masses one to eight times that of the sun (). the origin of their complex morphologies is poorly understood, although several mechanisms involving binary interaction have been proposed. in close binary systems, the orbital separation is short enough for the ... | the double-degenerate, super-chandrasekhar nucleus of the planetary nebula henize 2-428 |
we present measurements of the electron-temperature-based oxygen abundance for a highly star-forming galaxy at z = 3.08, cosmos-1908. this is the highest redshift at which [o iii]λ4363 has been detected and the first time that this line has been measured at z\gt 2. we estimate an oxygen abundance of 12+{log}({{o}}/{{h}... | the mosdef survey: detection of [o iii]λ4363 and the direct-method oxygen abundance of a star-forming galaxy at z = 3.08 |
we test the predictions of spectral synthesis models based on seven different massive-star prescriptions against legacy extragalactic uv survey (legus) observations of eight young massive clusters in two local galaxies, ngc 1566 and ngc 5253, chosen because predictions of all seven models are available at the published... | a comprehensive comparative test of seven widely used spectral synthesis models against multi-band photometry of young massive-star clusters |
context. surveys of protoplanetary disks in star-forming regions of similar age revealed significant variations in average disk mass in some regions. for instance, disks in the orion nebular cluster (onc) and corona australis (cra) are on average smaller than disks observed in lupus, taurus, chamaeleon i, or ophiuchus.... | ionization: a possible explanation for the difference of mean disk sizes in star-forming regions |
we present the largest and deepest late-time radio and millimeter survey to date of superluminous supernovae (slsne) and long-duration gamma-ray bursts (lgrbs) to search for associated nonthermal synchrotron emission. using the karl g. jansky very large array (vla) and the atacama large millimeter/submillimeter array (... | late-time radio and millimeter observations of superluminous supernovae and long gamma-ray bursts: implications for central engines, fast radio bursts, and obscured star formation |
optical, near-infrared (nir) photometric and spectroscopic studies, along with the optical imaging polarimetric results for sn 2012au, are presented in this article to constrain the nature of the progenitor and other properties. well-calibrated multiband optical photometric data (from -0.2 to +413 d since b-band maximu... | photometric, polarimetric, and spectroscopic studies of the luminous, slow-decaying type ib sn 2012au |
cr isotopic compositions have been measured on carbonaceous chondrites (cc): tafassasset, paris, niger i, nwa 5958, nwa 8157 and jbilet winselwan. in bulk samples, the 54cr/52cr ratios (expressed as ɛ54cr) range from 0.93 to 1.58 ɛ units. these values are in agreement with values characteristic for distinct petrologic ... | mn-cr systematics in primitive meteorites: insights from mineral separation and partial dissolution |
we have used hydrodynamical simulations to model the formation of the closest giant elliptical galaxy centaurus a. we find that a single major merger event with a mass ratio of up to 1.5, and which has happened ~2 gyr ago, is able to reproduce many of its properties, including galaxy kinematics, the inner gas disc, ste... | a recent major merger tale for the closest giant elliptical galaxy centaurus a |
the rotten egg nebula has at its core a binary composed of a mira star and an a-type companion at a separation >10 au. it has been hypothesized to have formed by strong binary interactions between the mira and a companion in an eccentric orbit during periastron passage ∼800 yr ago. we have performed hydrodynamic sim... | hydrodynamic simulations of the interaction between an agb star and a main-sequence companion in eccentric orbits |
photoionization models of h ii regions require as input a description of the ionizing spectral energy distribution (sed) and of the gas distribution, in terms of ionization parameter u and chemical abundances (e.g., o/h and n/o).a strong degeneracy exists between the hardness of the sed and u, which in turn leads to hi... | photoionization models of the califa h ii regions. i. hybrid models |
we investigate the environmental effect on the metal enrichment of star-forming galaxies (sfgs) in the farthest spectroscopically confirmed and x-ray-detected cluster, cl j1449+0856 at z = 1.99. we combined hubble space telescope/wfc3 g141 slitless spectroscopic data, our thirteen-band photometry, and a recent subaru/m... | metal deficiency in cluster star-forming galaxies at z = 2 |
context. studies of nearby galaxies reveal that around 50% of the total hα luminosity in late-type spirals originates from diffuse ionised gas (dig), which is a warm, diffuse component of the interstellar medium that can be associated with various mechanisms, the most important ones being "leaking" hii regions, evolved... | studying the ism at ∼10 pc scale in ngc 7793 with muse. i. data description and properties of the ionised gas |
context. recently published high-quality omegacam photometry of the 3 × 3 deg around the orion nebula cluster (onc) in r, and i filters revealed three well-separated pre-main sequences in the color-magnitude diagram (cmd). the objects belonging to the individual sequences are concentrated toward the center of the onc. ... | when the tale comes true: multiple populations and wide binaries in the orion nebula cluster |
using recently acquired hubble space telescope nir observations (j, paβ, and h bands) of the nearby galaxy ngc 1313, we investigate the timescales required by a young star cluster to emerge from its natal cloud. we search for extincted star clusters, potentially embedded in their natal cloud as either (1) compact sourc... | looking for obscured young star clusters in ngc 1313 |
context. we present our observations and analysis of sn 2020cxd, a low-luminosity (ll), long-lived type iip supernova (sn). this object is a clear outlier in the magnitude-limited sn sample recently presented by the zwicky transient facility's (ztf) bright transient survey.aims: we demonstrate that sn 2020cxd is an add... | a low-energy explosion yields the underluminous type iip sn 2020cxd |
the nature of the peculiar "ca-rich" sn 2019ehk in the nearby galaxy m100 remains unclear. its origin has been debated as either a stripped core-collapse supernova or a thermonuclear helium detonation event. here, we present very late-time photometry of the transient obtained with the keck i telescope at ≈280 days from... | the peculiar ca-rich sn2019ehk: evidence for a type iib core-collapse supernova from a low-mass stripped progenitor |
we present the first quantitative spectral analysis of blue supergiant stars in the nearby galaxy ngc 2403. out of a sample of 47 targets observed with the lris spectrograph at the keck i telescope we have extracted 16 b- and a-type supergiants for which we have data of sufficient quality to carry out a comparison with... | the metallicity and distance of ngc 2403 from blue supergiants |
infrared emission lines arising from transitions between fine structure levels of heavy elements are expected to produce kilonova nebular emission. for the kilonova in gw170817, strong emission at $4.5\, {\rm \mu m}$ at late times was detected by the spitzer space telescope but no source was detected at $3.6\, {\rm \mu... | tungsten versus selenium as a potential source of kilonova nebular emission observed by spitzer |
oxygen isotope ratios and corresponding 26al-26mg isotope systematics of refractory inclusions from the least metamorphosed carbonaceous chondrites, acfer 094 (c-ungrouped 3.00) and yamato 81020 (co3.05), were measured with an ion microprobe. most of the samples are fine-grained refractory inclusions which are consider... | a long duration of the 16o-rich reservoir in the solar nebula, as recorded in fine-grained refractory inclusions from the least metamorphosed carbonaceous chondrites |
short-lived radionuclides (slrs) once present in the solar nebula can be used as probes of the formation environment of our solar system within the milky way galaxy. the first-formed solids in the solar system, calcium-, aluminum-rich inclusions (cais) in meteorites, record the one-time existence of slrs such as 10be a... | uniform initial 10be/9be inferred from refractory inclusions in cv3, co3, cr2, and ch/cb chondrites |
a growing number of elements show well-resolved nucleosynthetic isotope anomalies in bulk-rock samples of solar system materials. in order to establish the occurrence and extent of such isotopic heterogeneities in zr, and to investigate the origin of the widespread heterogeneities in our solar system, new high-precisio... | zirconium isotope evidence for the heterogeneous distribution of s-process materials in the solar system |
this work extends previous kinematic studies of young stars in the head of the orion a cloud (omc-1/2/3/4/5). it is based on large samples of infrared, optical, and x-ray selected pre-main-sequence stars with reliable radial velocities and gaia-derived parallaxes and proper motions. stellar kinematic groups are identif... | gaia stellar kinematics in the head of the orion a cloud: runaway stellar groups and gravitational infall |
this paper is the second in a series presenting the results of our deep h α-line survey towards protoclusters at z > 2, based on narrow-band imaging with the subaru telescope. this work investigates massive galaxies in a protocluster region associated with a radio galaxy (pks 1138 - 262), the spiderweb galaxy, at z ... | mahalo deep cluster survey ii. characterizing massive forming galaxies in the spiderweb protocluster at z = 2.2 |
the single-degenerate scenario for type ia supernovae should yield metal-rich ejecta that enclose some stripped material from the non-degenerate h-rich companion star. we present a large grid of non-local thermodynamic equilibrium steady-state radiative transfer calculations for such hybrid ejecta and provide analytica... | spectral signatures of h-rich material stripped from a non-degenerate companion by a type ia supernova |
the nearby dwarf starburst galaxy ngc 5253 hosts a number of young, massive star clusters, the two youngest of which are centrally concentrated and surrounded by thermal radio emission (the “radio nebula”). to investigate the role of these clusters in the starburst energetics, we combine new and archival hubble space t... | the brightest young star clusters in ngc 5253. |
in this paper we present the results of our search for and study of z≳ 6 galaxy candidates behind the third frontier fields (ffs) cluster, macs j0717.5+3745, and its parallel field, combining data from hubble and spitzer. we select 39 candidates using the lyman break technique, for which the clear non-detection in opti... | young galaxy candidates in the hubble frontier fields. iii. macs j0717.5+3745 |
galaxy proto-clusters at z≳ 2 provide a direct probe of the rapid mass assembly and galaxy growth of present-day massive clusters. because of the need for precise galaxy redshifts for density mapping and the prevalence of star formation before quenching, nearly all the proto-clusters known to date were confirmed by spe... | surveying galaxy proto-clusters in emission: a large-scale structure at z = 2.44 and the outlook for hetdex |
context. atomic gas in the diffuse interstellar medium (ism) is organized in filamentary structures. these structures usually host cold and dense molecular clumps. the galactic magnetic field is considered to play an important role in the formation of these clumps.aims: our goal is to explore the role of the magnetic f... | hi-h2 transition: exploring the role of the magnetic field. a case study toward the ursa major cirrus |
we present three new spectra of the nearby type ia supernova (sn ia) 2011fe covering ≈480-850 days after maximum light and show that the ejecta undergoes a rapid ionization shift at ~500 days after explosion. the prominent fe iii emission lines at ≈4600 å are replaced with fe i+fe ii blends at ~4400 å and ~5400 å. the ... | a rapid ionization change in the nebular-phase spectra of the type ia sn 2011fe |
the kinematics and dynamics of stellar and substellar populations within young, still-forming clusters provide valuable information for constraining theories of formation mechanisms. using keck ii nirspec+ao data, we have measured radial velocities for 56 low-mass sources within 4' of the core of the orion nebula clust... | the 3d kinematics of the orion nebula cluster: nirspec-ao radial velocities of the core population |
jupiter's deep abundances help to constrain the formation history of the planet and the environment of the protoplanetary nebula. juno recently measured jupiter's deep oxygen abundance near the equator to be 2 .2−2.1+3.9 times the protosolar value (2σ uncertainties). even if the nominal value is supersolar, subsolar ab... | a subsolar oxygen abundance or a radiative region deep in jupiter revealed by thermochemical modelling |
interstellar carbonaceous dust is mainly formed in the innermost regions of circumstellar envelopes around carbon-rich asymptotic giant branch stars (agbs). in these highly chemically stratified regions, atomic and diatomic carbon, along with acetylene, are the most abundant species after h2 and co. in a previous study... | the chemistry of cosmic dust analogs from c, c2, and c2h2 in c-rich circumstellar envelopes |
during the common envelope (ce) phase, a giant star in a binary system overflows its roche lobe and unstable mass transfer leads to a spiral-in of the companion, resulting in a close binary system or in a merger of the stellar cores. dynamo processes during the ce phase have been proposed as a mechanism to generate mag... | magnetic field amplification during the common envelope phase |
we study the morphologies of core collapse supernova remnants (ccsnrs) and find that about third of ccsnrs in our sample have two opposite 'ears' protruding from their main shell. we assume that the ears are formed by jets, and argue that these properties are compatible with the expectation from the explosion jet feedb... | core collapse supernova remnants with ears |
we present near-ir imaging polarimetry of five classical fu ori-type objects (fu ori, v1057 cyg, v1515 cyg, v1735 cyg, z cma) with an ∼0.″1 resolution observed using hiciao+ao188 at the subaru telescope. we observed scattered light associated with circumstellar dust around four of them (i.e., all but v1515 cyg). their ... | near-infrared high-resolution imaging polarimetry of fu ori-type objects: toward a unified scheme for low-mass protostellar evolution |
ultrafast proton migration and isomerization are key processes for acetylene and its ions. however, the mechanism for ultrafast isomerization of acetylene [hcch]2+ to vinylidene [h2cc]2+ dication remains nebulous. theoretical studies show a large potential barrier ( > 2 ev) for isomerization on low-lying dicationic ... | ultrafast isomerization in acetylene dication after carbon k-shell ionization |
we combined the spectroscopic information from the 3d-hst survey with herschel data to characterize the hα dust attenuation properties of a sample of 79 main sequence star-forming galaxies at z ~ 1 in the goods-s field. the sample was selected in the far-ir at λ = 100 and/or 160 μm and only includes galaxies with a sec... | dust attenuation in z ~ 1 galaxies from herschel and 3d-hst hα measurements |
the observation of cosmic sub-pev gamma rays from the crab nebula opens up the possibility of testing cosmic ray photon transparency at the multi-hundred-tev scale. assuming no deviation from a source gamma-ray emission due to accelerated electron inverse-compton scattering, higher event energies can extend constraints... | axion and dark photon limits from crab nebula high-energy gamma rays |
stellar kinematics is a powerful tool for understanding the formation process of stellar associations. here, we present a kinematic study of the young stellar population in the rosette nebula using recent gaia data and high-resolution spectra. we first isolate member candidates using the published mid-infrared photomet... | a kinematic perspective on the formation process of the stellar groups in the rosette nebula |
we present photometric and spectroscopic observations of the interacting transient sn 2009ip taken during the 2013 and 2014 observing seasons. we characterize the photometric evolution as a steady and smooth decline in all bands, with a decline rate that is slower than expected for a solely 56co-powered supernova at la... | sn 2009ip at late times - an interacting transient at +2 years |
this study reports the bulk rare earth element (rees, la-lu) compositions of 41 chondrites, including 32 falls and 9 finds from carbonaceous (ci, cm, co and cv), enstatite (eh and el) and ordinary (h, l and ll) groups, as well as 2 enstatite achondrites (aubrite). the measurements were done in dynamic mode using multi-... | thulium anomalies and rare earth element patterns in meteorites and earth: nebular fractionation and the nugget effect |
nearby type iii (galaxy-spanning) kardashev supercivilizations would have high mid-infrared (mir) luminosities. we have used the wide-field infrared survey explorer (wise) to survey ∼ 1× {{10}5} galaxies for extreme mir emission, 1 × 103 times more galaxies than the only previous such search. we have calibrated the wis... | the ĝ infrared search for extraterrestrial civilizations with large energy supplies. iii. the reddest extended sources in wise |
binary evolution is indispensable in stellar evolution to understand the formation and evolution of most peculiar and energetic objects, such as binary compact objects, type ia supernovae, x-ray binaries, cataclysmic variables, blue stragglers, hot subdwarfs, and central binaries in planetary nebulae. mass transfer in ... | the thermal equilibrium mass-loss model and its applications in binary evolution |
we present the alma band 3 and band 6 results of 12co(2-1), 13co(2-1), h30α recombination line, free-free emission around 98 ghz, and the dust thermal emission around 230 ghz toward the n159 east giant molecular cloud (n159e) in the large magellanic cloud (lmc). lmc is the nearest active high-mass star-forming face-on ... | kinematic structure of molecular gas around high-mass yso, papillon nebula, in n159 east in the large magellanic cloud: a new perspective with alma |
we investigate the kinematic properties of nine nearby early-type galaxies with evidence of a disc-like component. three of these galaxies are located in the field, five in the group, and only one in the cluster environment. by combining the kinematics of the stars with those of the globular clusters (gcs) and planetar... | the sluggs survey: combining stars, globular clusters, and planetary nebulae to understand the assembly history of early-type galaxies from their large radii kinematics |
the [o iii] λ5007 planetary nebula luminosity function (pnlf) is an established distance indicator that has been used for more than 30 yr to measure the distances of galaxies out to ~15 mpc. with the advent of the multi-unit spectroscopic explorer on the very large telescope (muse) as an efficient wide-field integral-f... | toward precision cosmology with improved pnlf distances using vlt-musei. methodology and tests |
nebular emission lines associated with galactic h ii regions carry information about both physical properties of the ionized gas and the source of ionizing photons as well as providing the opportunity of measuring accurate redshifts and thus distances once a cosmological model is assumed. while nebular-line emission ha... | nebular-line emission during the epoch of reionization |
the merger of two white dwarfs (wds) is a natural outcome of the evolution of many binary stars. recently, a wd merger product, iras 00500+6713, was identified. iras 00500+6713 consists of a central star embedded in a circular nebula. the analysis of the optical spectrum of the central star revealed that it is hot, hyd... | x-rays observations of a super-chandrasekhar object reveal an one and a co white dwarf merger product embedded in a putative sn iax remnant |
the goal of population spectral synthesis (pss; also referred to as inverse, semi-empirical evolutionary- or fossil record approach) is to decipher from the spectrum of a galaxy the mass, age and metallicity of its constituent stellar populations. this technique, which is the reverse of but complementary to evolutionar... | fitting analysis using differential evolution optimization (fado):. spectral population synthesis through genetic optimization under self-consistency boundary conditions |
we report oxygen, calcium, titanium and 26al-26mg isotope systematics for spinel-hibonite inclusions (shibs), a class of calcium-aluminum-rich inclusions (cai) common in cm chondrites. in contrast to previous studies, our analyses of 33 shibs and four shib-related objects obtained with high spatial resolution demonstra... | new constraints on the relationship between 26al and oxygen, calcium, and titanium isotopic variation in the early solar system from a multielement isotopic study of spinel-hibonite inclusions |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.