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the optical observations of ic-4 supernova (sn) 2016coi/asassn-16fp, from ∼2 to ∼450 d after explosion, are presented along with analysis of its physical properties. the sn shows the broad lines associated with sne ic-3/4 but with a key difference. the early spectra display a strong absorption feature at ∼5400 å which ... | sn 2016coi/asassn-16fp: an example of residual helium in a typeic supernova? |
exoplanets have been observed around stars at all stages of stellar evolution, in many cases orbiting in configurations that will eventually lead to the planets being engulfed or consumed by their host stars, such as hot jupiters or ultrashort period planets. furthermore, objects such as polluted white dwarfs provide s... | eating planets for lunch and dinner: signatures of planet consumption by evolving stars |
numerous superluminous supernovae (slsne) of type ic have been discovered and monitored in the last decade. the favored mechanism at their origin is a sustained power injection from a magnetar. this study presents non-local thermodynamic equilibrium (nlte) time-dependent radiative transfer simulations of various single... | simulations of light curves and spectra for superluminous type ic supernovae powered by magnetars |
interpreting observations of distant galaxies in terms of constraints on physical parameters - such as stellar mass (m★), star formation rate (sfr) and dust optical depth ({hat{τ}v}) - requires spectral synthesis modelling. we analyse the reliability of these physical parameters as determined under commonly adopted `cl... | on the importance of using appropriate spectral models to derive physical properties of galaxies at 0.7 < z < 2.8 |
we present extensive ultraviolet, optical, and near-infrared observations of the type iip supernova (sn iip) 2013ej in the nearby spiral galaxy m74. the multicolor light curves, spanning from ∼8-185 days after explosion, show that it has a higher peak luminosity (i.e., mv ∼ -17.83 mag at maximum light), a faster post-p... | sn 2013ej in m74: a luminous and fast-declining type ii-p supernova |
we present optical photometric and spectroscopic observations of sn 2013ej. it is one of the brightest type ii supernovae (sne ii) exploded in a nearby (∼10 mpc) galaxy, ngc 628. the light-curve characteristics are similar to sne ii, but with a relatively shorter (∼85 days) and steeper (∼1.7 mag (100 days)-1 in v) plat... | sn 2013ej: a type iil supernova with weak signs of interaction |
we investigate the properties of ∼7000 narrow-band selected galaxies with strong hβ+[o iii] and [o ii] nebular emission lines from the high-z emission-line survey between z ∼ 0.8 and 5.0. our sample covers a wide range in stellar mass (mstellar ∼ 107.5-12.0 m⊙), rest-frame equivalent widths (ewrest∼10-105 å), and line ... | the nature of hβ+[o iii] and [o ii] emitters to z ∼ 5 with hizels: stellar mass functions and the evolution of ews |
we present a set of nonlocal thermodynamic equilibrium steady-state calculations of radiative transfer for one-year-old type ii supernovae (sne) starting from state-of-the-art explosion models computed with detailed nucleosynthesis. this grid covers single-star progenitors with initial masses between 9 and 29 m⊙, all e... | the explosion of 9-29 m⊙ stars as type ii supernovae: results from radiative-transfer modeling at one year after explosion |
we present new diagnostic tools for distinguishing supernova remnants (snrs) from h ii regions. up to now, sources with flux ratio [s ii]/h{α } higher than 0.4 have been considered as snrs. here, we present combinations of three or two line ratios as more effective tools for the separation of these two kinds of nebulae... | a diagnostic tool for the identification of supernova remnants |
the ratio between the two stable isotopes of nitrogen, 14n and 15n, is well measured in the terrestrial atmosphere ( 272), and for the pre-solar nebula ( 441, deduced from the solar wind). interestingly, some pristine solar system materials show enrichments in 15n with respect to the pre-solar nebula value. however, it... | nitrogen and hydrogen fractionation in high-mass star-forming cores from observations of hcn and hnc |
aims: we present kinematic and photometric evidence for an accretion event in the halo of the cd galaxy m 87 in the last gyr.methods: using velocities for ~300 planetary nebulas (pns) in the m 87 halo, we identify a chevron-like substructure in the pn phase-space. we implement a probabilistic gaussian mixture model to ... | the build-up of the cd halo of m 87: evidence for accretion in the last gyr |
we discuss the events that led to the giant eruption of eta carinae, and find that the mid-nineteenth century (in 1838-1843) giant mass-loss outburst has the characteristics of being produced by the merger event of a massive close binary, triggered by the gravitational interaction with a massive third companion star, w... | was the nineteenth century giant eruption of eta carinae a merger event in a triple system? |
we present alma co(1-0) and co(3-2) observations of the brightest cluster galaxy (bcg) in the 2a 0335+096 galaxy cluster (z = 0.0346). the total molecular gas mass of 1.13 ± 0.15 × 109 m ⊙ is divided into two components: a nuclear region and a 7 kpc long dusty filament. the central molecular gas component accounts for ... | molecular gas along a bright hα filament in 2a 0335+096 revealed by alma |
we present near-infrared and optical spectroscopic observations of a sample of 450 and 850 μm-selected dusty star-forming galaxies (dsfgs) identified in a 400 arcmin2 area in the cosmos field. thirty-one sources of the 114 targets were spectroscopically confirmed at 0.2< z< 4, identified primarily in the near-inf... | near-infrared mosfire spectra of dusty star-forming galaxies at 0.2 < z < 4 |
the combination of precise radial velocities from multi-object spectroscopy and highly accurate proper motions from gaia dr2 opens up the possibility for detailed 3d kinematic studies of young star-forming regions and clusters. here, we perform such an analysis by combining gaia-eso survey spectroscopy with gaia astrom... | the gaia-eso survey: asymmetric expansion of the lagoon nebula cluster ngc 6530 from ges and gaia dr2 |
argon, krypton, xenon, carbon, nitrogen, sulfur, and phosphorus have all been measured and found to be enriched by a quasi uniform factor in the 2-4 range, compared to their protosolar values, in the atmosphere of jupiter. to elucidate the origin of these volatile enrichments, we investigate the possibility of an inwar... | jupiter’s formation in the vicinity of the amorphous ice snowline |
we present an overview of sitelle, an imaging fourier transform spectrometer (ifts) available at the 3.6-m canada-france-hawaii telescope. sitelle is a michelson-type interferometer able to reconstruct the spectrum of every light source within its 11 arcmin field of view in filter-selected bands of the visible (350-900... | sitelle: an imaging fourier transform spectrometer for the canada-france-hawaii telescope |
we compute successfully the launching of two magnetic winds from two circumbinary disks formed after a common envelope event. the launching is produced by the increase of magnetic pressure due to the collapse of the disks. the collapse is due to internal torques produced by a weak poloidal magnetic field. the first win... | common envelope shaping of planetary nebulae. iii. the launching of jets in proto-planetary nebulae |
we present new photometric and spectroscopic observations of sn 2019yvq, a type ia supernova (sn ia) exhibiting several peculiar properties including an excess of uv/optical flux within days of explosion, a high si ii velocity, and a low peak luminosity. photometry near the time of first light places new constraints on... | sn 2019yvq does not conform to sn ia explosion models |
we present the discovery and extensive follow-up observations of sn 2020jfo, a type iip supernova (sn) in the nearby (14.5 mpc) galaxy m 61. optical light curves (lcs) and spectra from the zwicky transient facility (ztf), complemented with data from swift/uvot and near-infrared photometry is presented. these were used ... | the type ii supernova sn 2020jfo in m 61, implications for progenitor system, and explosion dynamics |
this work examines the relationships between the properties (flux ratios, full width at half-maximum velocities) of the [o i] λλ6300, 6364, [ca ii] λλ7291, 7323, and the ca ii near-infrared triplet, emission lines of a large sample of core-collapse supernovas (sne) and ca-rich transients (509 spectra of 86 transients, ... | oxygen and calcium nebular emission line relationships in core-collapse supernovae and ca-rich transients |
studying the driving modes of turbulence is important for characterizing the impact of turbulence in various astrophysical environments. the driving mode of turbulence is parametrized by b, which relates the width of the gas density pdf to the turbulent mach number; b ≈ 1/3, 1, and 0.4 correspond to driving that is sol... | first extragalactic measurement of the turbulence driving parameter: alma observations of the star-forming region n159e in the large magellanic cloud |
context. the andromeda (m31) galaxy presents evidence of recent substantial mass accretion. this is unlike what has happened in the milky way, which has experienced a rather quiescent evolution.aims: we use oxygen and argon abundances for planetary nebulae (pne) with low internal extinction (progenitor ages of > 4.5... | the survey of planetary nebulae in andromeda (m31). v. chemical enrichment of the thin and thicker discs of andromeda: oxygen to argon abundance ratios for planetary nebulae and hii regions |
recently, intense emission from nebular c iii] and c iv emission lines have been observed in galaxies in the epoch of reionization (z > 6) and have been proposed as the prime way of measuring their redshift and studying their stellar populations. these galaxies might represent the best examples of cosmic reionizers,... | insights into the reionization epoch from cosmic-noon-c iv emitters in the vandels survey |
context. while it is generally assumed that class ii sources evolve largely in isolation from their environment, many still lie close to molecular clouds and may continue to interact with them. this may result in late accretion of material onto the disk that can significantly influence disk processes and planet formati... | reflections on nebulae around young stars. a systematic search for late-stage infall of material onto class ii disks |
there is significant astronomical interest around the intense mass loss that appears to take place in some massive stars immediately before core collapse. however, because it occurs too late, it has a negligible impact on the star's evolution or the final yields. these properties are then influenced instead by the long... | the morphing of decay powered to interaction powered type ii supernova ejecta at nebular times |
signals, the star formation, ionized gas, and nebular abundances legacy survey, is a large observing programme designed to investigate massive star formation and h ii regions in a sample of local extended galaxies. the programme will use the imaging fourier transform spectrograph sitelle at the canada-france-hawaii tel... | signals: i. survey description |
we present observations from the first light infrared test camera (flitecam) on board the stratospheric observatory for infrared astronomy, the spitzer infrared array camera (irac), and the spitzer infrared spectrograph sh mode in three well-known photodissociation regions, the reflection nebulae (rne) ngc 7023 and ngc... | tracing pah size in prominent nearby mid-infrared environments |
context. reconstructing the structure and history of young clusters is pivotal to understanding the mechanisms and timescales of early stellar evolution and planet formation. recent studies suggest that star clusters often exhibit a hierarchical structure, possibly resulting from several star formation episodes occurri... | the gaia-eso survey and csi 2264: substructures, disks, and sequential star formation in the young open cluster ngc 2264 |
aims: as a new approach to the study of resolved stellar populations in nearby galaxies, our goal is to demonstrate with a pilot study in ngc 300 that integral field spectroscopy with high spatial resolution and excellent seeing conditions reaches an unprecedented depth in severely crowded fields.methods: observations ... | muse crowded field 3d spectroscopy in ngc 300. i. first results from central fields |
we present atacama large millimeter array co(3 - 2) and hco+(4 - 3) observations covering the central 1'5 × 1'5 region of the orion nebula cluster (onc). the unprecedented level of sensitivity (∼0.1 mjy beam-1) and angular resolution (∼0"09 ≈ 40 au) of these line observations enable us to search for gas-disk detections... | protoplanetary disks in the orion nebula cluster: gas-disk morphologies and kinematics as seen with alma |
common envelope (ce) evolution is a critical but still poorly understood progenitor phase of many high-energy astrophysical phenomena. although 3d global hydrodynamic ce simulations have become more common in recent years, those involving an asymptotic giant branch (agb) primary are scarce, due to the high computationa... | common envelope evolution on the asymptotic giant branch: unbinding within a decade? |
star-forming galaxies with strong nebular and collisional emission lines are privileged target galaxies in forthcoming cosmological large galaxy redshift surveys. we use the cosmos2015 photometric catalogue to model galaxy spectral energy distributions and emission-line fluxes. we adopt an empirical but physically moti... | the synthetic emission line cosmos catalogue: hα and [o ii] galaxy luminosity functions and counts at 0.3 < z < 2.5 |
we calculate the evolution of gas giant planets during the runaway gas accretion phase of formation, to understand how the luminosity of young giant planets depends on the accretion conditions. we construct steady-state envelope models, and run time-dependent simulations of accreting planets with the code modules for e... | the evolution of gas giant entropy during formation by runaway accretion |
the star-forming region of the orion nebula (onc) is ideal to study the stellar dynamics of young stars in a clustered environment. using gaia dr2 we search for pre-main sequence stars with unusually high proper motions that may be representative of a dynamical ejection from unstable young triple systems or other close... | runaway young stars near the orion nebula |
ck vul is the remnant of an energetic eruption known as nova 1670 that is thought to be caused by a stellar merger. the remnant is composed of (1) a large hourglass nebula of recombining gas (of 71'' in size), very similar to some classical planetary and pre-planetary nebulae (ppne), and (2) a much smaller and cooler i... | molecular remnant of nova 1670 (ck vulpeculae). ii. a three-dimensional view of the gas distribution and velocity field |
we present new hubble space telescope cosmic origins spectrograph far-ultraviolet (far-uv) spectroscopy and keck echellete optical spectroscopy of 11 ultraluminous infrared galaxies (ulirgs), a rare population of local galaxies experiencing massive gas inflows, extreme starbursts, and prominent outflows. we detect lyα ... | the lyα line profiles of ultraluminous infrared galaxies: fast winds and lyman continuum leakage |
we report on the detection of a bright, short, structured x-ray burst coming from the supernova remnant rcw 103 on 2016 june 22 caught by the swift/burst alert telescope (bat) monitor, and on the follow-up campaign made with swift/x-ray telescope, swift/uv/optical telescope, and the optical/near-infrared (nir) gamma-ra... | evidence for the magnetar nature of 1e 161348-5055 in rcw 103 |
the primordial helium abundance yp is calculated using sulphur as metallicity tracer in the classical methodology (with yp as an extrapolation of y to zero metals). the calculated value, yp, s= 0.244 ± 0.006, is in good agreement with the estimate from the planck experiment, as well as, determinations in the literature... | primordial helium abundance determination using sulphur as metallicity tracer |
context. in the theory of pebble accretion, planets form by the subsequent accretion of solids (micron-sized dust and larger pebbles) and gas. the amount of nebular gas that a planet can bind is limited by its cooling rate, which is set by the opacity of its envelope. accreting dust and pebbles contribute to the envelo... | how planets grow by pebble accretion. iv. envelope opacity trends from sedimenting dust and pebbles |
we present optical photometry and spectroscopy of sn 2016iet (=gaia16bvd=ps17brq), an unprecedented type i supernova (sn i) at z = 0.0676 with no obvious analog in the existing literature. sn 2016iet exhibits a peculiar light curve, with two roughly equal brightness peaks (≈ -19 mag) separated by about 100 days, and a ... | sn 2016iet: the pulsational or pair instability explosion of a low-metallicity massive co core embedded in a dense hydrogen-poor circumstellar medium |
the javalambre-physics of the accelerating universe astrophysical survey (j-pas) is expected to map thousands of square degrees of the northern sky with 56 narrowband filters (spectral resolution of r ∼ 60) in the upcoming years. this resolution allows us to study emission line galaxies (elgs) with a minimum equivalent... | the minijpas survey: identification and characterization of the emission line galaxies down to z < 0.35 in the aegis field |
among the nearest most metal-poor starburst-dwarf galaxies known, sbs 0335-052e is the most luminous in integrated nebular he ii λ4686 emission. this makes it a unique target to test spectral synthesis models and spectral interpretation tools of the kind that will be used to interpret future rest-frame uv observations ... | stars and gas in the most metal-poor galaxies - i. cos and muse observations of sbs 0335-052e |
the nebular circumstellar environments of cool evolved stars are known to harbour a rich morphological complexity of gaseous structures on different length scales. a large part of these density structures are thought to be brought about by the interaction of the stellar wind with a close companion. the s-type asymptoti... | atomium: a high-resolution view on the highly asymmetric wind of the agb star π1gruis. i. first detection of a new companion and its effect on the inner wind |
the nebular spectra of type ia supernovae (⪆100 d after explosion) consist mainly of emission lines from singly and doubly ionized fe-group nuclei. however, theoretical models for many scenarios predict that non-thermal ionization leads to multiply ionized species whose recombination photons ionize and deplete fe+, res... | modelling the ionization state of type ia supernovae in the nebular phase |
the gas pixel detector (gpd) is designed and developed for high-sensitivity astronomical x-ray polarimetry, which is a new window about to open in a few years. due to the small mass, low power, and compact geometry of the gpd, we propose a cubesat mission polarimeter light (polarlight) to demonstrate and test the techn... | polarlight: a cubesat x-ray polarimeter based on the gas pixel detector |
we used the space telescope imaging spectrograph on the hubble space telescope (hst) to observe the semiforbidden c iii] λλ1907, 1909 doublet emission in green pea galaxies at 0.13 ≤ z ≤ 0.3. we detect c iii] emission in 7/10 galaxies with c iii] equivalent widths (ews) that range from 2 to 10 å, confirming that c iii]... | the semiforbidden c iii] λ1909 emission in the rest-ultraviolet spectra of green pea galaxies |
recent integral field spectroscopic (ifs) surveys have revealed radial gradients in the optical spectral indices of post-starburst (psb) galaxies, which can be used to constrain their formation histories. we study the spectral indices of post-processed mock ifs datacubes of binary merger simulations, carefully matched ... | comparison of stellar populations in simulated and real post-starburst galaxies in manga |
we present a strong and weak lensing reconstruction of the massive cluster abell 2744, the first cluster for which deep hubble frontier fields (hff) images and spectroscopy from the grism lens-amplified survey from space (glass) are available. by performing a targeted search for emission lines in multiply imaged source... | the grism lens-amplified survey from space (glass). iv. mass reconstruction of the lensing cluster abell 2744 from frontier field imaging and glass spectroscopy |
context. model atmosphere analyses have been previously undertaken for both galactic and extragalactic b-type supergiants. by contrast, little attention has been given to a comparison of the properties of single supergiants and those that are members of multiple systems.aims: atmospheric parameters and nitrogen abundan... | the vlt-flames tarantula survey. xix. b-type supergiants: atmospheric parameters and nitrogen abundances to investigate the role of binarity and the width of the main sequence |
we present an extended grid of multi-epoch 1d nonlocal thermodynamic equilibrium radiative transfer calculations for nebular-phase type ibc supernovae (sne) from he-star explosions. compared to our previous work, which was focused on a post-explosion epoch of 200 days, here we study the spectral evolution from 100 to a... | modeling of the nebular-phase spectral evolution of stripped-envelope supernovae. new grids from 100 to 450 days |
we present new spectroscopic observations of ly α (ly α) blob 2 (z ~ 3.1). we observed extended ly α emission in three distinct regions, where the highest ly α surface brightness (sb) centre is far away from the known continuum sources. we searched through the mosfire slits that cover the high ly α sb regions, but were... | where outflows meet inflows: gas kinematics in ssa22 ly α blob 2 decoded by advanced radiative transfer modelling |
context. the andromeda (m 31) galaxy subtends nearly 100 square degrees on the sky. any study of its halo must therefore account for the severe contamination from the milky way halo stars whose surface density displays a steep gradient across the entire m 31 field of view.aims: our goal is to identify a population of s... | the survey of planetary nebulae in andromeda (m 31). i. imaging the disc and halo with megacam at the cfht |
1es 1959+650 is a bright tev high-frequency-peaked bl lac object exhibiting interesting features like "orphan" tev flares and broad emission in the high-energy regime that are difficult to interpret using conventional one-zone synchrotron self-compton (ssc) scenarios. we report the results from the major atmospheric ga... | broadband characterisation of the very intense tev flares of the blazar 1es 1959+650 in 2016 |
the orion nebula cluster (onc) is the most massive region of active star formation within a kpc of the sun. using gaia dr3 parallaxes and proper motions, we examine the bulk motions of stars radially and tangentially relative to the cluster centre. we find an age gradient with distance to the stars in the onc, from 385... | a gravitational and dynamical framework of star formation: the orion nebula |
we present observations of three core-collapse supernovae (ccsne) in elliptical hosts, detected by the zwicky transient facility bright transient survey (bts). sn 2019ape is a sn ic that exploded in the main body of a typical elliptical galaxy. its properties are consistent with an explosion of a regular sn ic progenit... | less than 1% of core-collapse supernovae in the local universe occur in elliptical galaxies |
context. the presence of large ionised gaseous nebulae found around some ultraluminous x-ray sources (ulxs) provides the means to assess the mechanical and radiative feedback of the central source, and hence constrain the efficiency and impact on the surroundings of the super-eddington regime powering most of these sou... | muse spectroscopy of the ulx ngc 1313 x-1: a shock-ionised bubble, an x-ray photoionised nebula, and two supernova remnants |
the baldwin, philips, & terlevich diagram of [o iii]/hβ versus [n ii]/hα (hereafter n2-bpt) has long been used as a tool for classifying galaxies based on the dominant source of ionizing radiation. recent observations have demonstrated that galaxies at z ~ 2 reside offset from local galaxies in the n2-bpt space. in... | the bpt diagram in cosmological galaxy formation simulations: understanding the physics driving offsets at high redshift |
context. r aqr is a symbiotic binary system consisting of a mira variable, a hot companion with a spectacular jet outflow, and an extended emission line nebula. because of its proximity to the sun, this object has been studied in much detail with many types of high resolution imaging and interferometric techniques. we ... | sphere/zimpol observations of the symbiotic system r aquarii. i. imaging of the stellar binary and the innermost jet clouds |
we present the final data release of the apex low-redshift legacy survey for molecular gas (allsmog), comprising co(2-1) emission line observations of 88 nearby, low-mass (108.5<m∗ [m⊙] < 1010) star-forming galaxies carried out with the 230 ghz apex-1 receiver on the apex telescope. the main goal of allsmog is to... | the final data release of allsmog: a survey of co in typical local low-m∗ star-forming galaxies |
we study a sample of 16 type ia supernovae (sne ia) having both spectroscopic and photometric observations within 2-3 days after the first light. the early b - v colors of such a sample tend to show a continuous distribution. for objects with normal ejecta velocity (nv), the c ii λ6580 feature is always visible in the ... | can the helium-detonation model explain the observed diversity of type ia supernovae? |
the earth and other rocky planets and planetesimals in the solar system formed through the mixing of materials from various radial locations in the solar nebula. this primordial material likely had a range of oxidation states as well as bulk compositions and volatile abundances. we investigate the oxygen fugacity produ... | redox states of initial atmospheres outgassed on rocky planets and planetesimals |
the bright southern star l2 pup is a particularly prominent asymptotic giant branch (agb) star, located at a distance of only 64 pc. we report new adaptive optics observations of l2 pup at visible wavelengths with the sphere/zimpol instrument of the vlt that confirm the presence of the circumstellar dust disk discovere... | the dust disk and companion of the nearby agb star l2 puppis. sphere/zimpol polarimetric imaging at visible wavelengths |
we report the identification of extended lyα nebulae at z ≃ 3.3 in the hubble ultra deep field (hudf, ≃40 kpc × 80 kpc) and behind the hubble frontier field galaxy cluster macsj0416 (≃40 kpc), spatially associated with groups of star-forming galaxies. vlt/muse integral field spectroscopy reveals a complex structure wit... | illuminating gas inflows/outflows in the muse deepest fields: lyα nebulae around forming galaxies at z ≃ 3.3 |
a previous spectroscopic study identified the very massive o2 iii star vfts 16 in the tarantula nebula as a runaway star based on its peculiar line-of-sight velocity. we use the gaia dr2 catalog to measure the relative proper motion of vfts 16 and nearby bright stars to test if this star might have been ejected from th... | gaia dr2 reveals a very massive runaway star ejected from r136 |
nanosims c-, n-, and o-isotopic mapping of matrix in co3.0 chondrite dominion range (dom) 08006 revealed it to have in its matrix the highest abundance of presolar o-rich grains (257 +76/-96 ppm, 2σ) of any meteorite. it also has a matrix abundance of presolar sic of 35 (+25/-17, 2σ) ppm, similar to that seen across pr... | high abundances of presolar grains and 15n-rich organic matter in co3.0 chondrite dominion range 08006 |
this paper compares parameters that characterize vegetation flexibility effects on flow resistance and drag. drag forces have been measured in a flume for simple cylindrical obstructions of the same shape and size but with different flexibility under several flow conditions. this data set is used to fit drag parameters... | drag force parameters of rigid and flexible vegetal elements |
we present a semi-empirical calibration between the metallicity (z) of seyfert 2 active galactic nuclei and the n2 = log([n ii]λ6584/h α) emission-line intensity ratio. this calibration was derived through the [o iii]λ5007/[o ii]λ3727 versus n2 diagram containing observational data and photoionization model results obt... | chemical abundances of seyfert 2 agns - ii. n2 metallicity calibration based on sdss |
in this second paper in a series of papers based on the most-up-to-date catalogue of symbiotic stars (systs), we present a new approach for identifying and distinguishing systs from other h α emitters in photometric surveys using machine learning algorithms such as classification tree, linear discriminant analysis, and... | a machine learning approach for identification and classification of symbiotic stars using 2mass and wise |
veritas is a ground-based gamma-ray instrument operating at the fred lawrence whipple observatory in southern arizona. with an array of four imaging atmospheric cherenkov telescopes (iacts), veritas is designed to measure gamma rays with energies from $\sim$ 85 gev up to > 30 tev. it has a sensitivity to detect a po... | performance of the veritas experiment |
we present x-ray spectral analysis of 20 point-like x-ray sources detected in chandra planetary nebula survey observations of 59 planetary nebulae (pne) in the solar neighborhood. most of these 20 detections are associated with luminous central stars within relatively young, compact nebulae. the vast majority of these ... | the chandra planetary nebula survey (chanplans). iii. x-ray emission from the central stars of planetary nebulae |
we present the first direct image of the high-metallicity gas component in a planetary nebula (ngc 6778), taken with the osiris blue tunable filter centered on the o ii λ4649+50 å optical recombination lines (orls) at the 10.4 m gran telescopio canarias. we show that the emission of these faint o ii orls is concentrate... | imaging the elusive h-poor gas in the high adf planetary nebula ngc 6778 |
parameterizing hypothetical violation of lorentz invariance at high energies using the framework of effective quantum field theory, we discuss its effect on the formation of atmospheric showers by very-high-energy gamma rays. in the scenario where lorentz invariance violation leads to a decrease of the photon velocity ... | constraints on violation of lorentz invariance from atmospheric showers initiated by multi-tev photons |
this is the first paper of a series dedicated to nebular physics and the chemical evolution of nearby galaxies by investigating large samples of h ii regions with the canada-france-hawaii telescope imaging spectrograph sitelle (spectro-imageur à transformée de fourier pour l'étude en long et en large des raies d'émissi... | ngc628 with sitelle: i. imaging spectroscopy of 4285 h ii region candidates |
recently, three stellar sequences separated in age by about 1 myr were discovered in the orion nebula cluster (onc; beccari et al. 2017). kroupa et al. (2018) suggest that such small dense subpopulations eject all their ob stars via the decay of unstable few-body systems such that the gas can recombine and form new sta... | complete ejection of ob stars from very young star clusters and the formation of multiple populations |
the fractionation of nitrogen (n) in star-forming regions is a poorly understood process. to put more stringent observational constraints on the n-fractionation, we have observed with the iram-30-m telescope a large sample of 66 cores in massive star-forming regions. we targeted the (1-0) rotational transition of hn13c... | nitrogen fractionation in high-mass star-forming cores across the galaxy |
we apply novel survival analysis techniques to investigate the relationship between a number of the properties of galaxies and their atomic (m h i ) and molecular ({m}{{{h}}2}) gas mass, with the aim of devising efficient, effective empirical estimators of the cold gas content in galaxies that can be applied to large o... | dirt-cheap gas scaling relations: using dust absorption, metallicity, and galaxy size to predict gas masses for large samples of galaxies |
the final steps of the evolution of massive stars leading to a supernova explosion, in particular the mass-loss mechanism, is an important open problem in astrophysics. stripped-envelope supernovae (sesne) are explosions of massive stars where a large amount of the outer envelope has been stripped away before the explo... | a hybrid envelope-stripping mechanism for massive stars from supernova nebular spectroscopy |
high-energy astrophysical systems frequently contain collision-less relativistic plasmas that are heated by turbulent cascades and cooled by emission of radiation. understanding the nature of this radiative turbulence is a frontier of extreme plasma astrophysics. in this paper, we use particle-in-cell simulations to st... | kinetic turbulence in shining pair plasma: intermittent beaming and thermalization by radiative cooling |
a very small fraction of (runaway) massive stars have masses exceeding 60-70 m_{⊙} and are predicted to evolve as luminous blue variable and wolf-rayet stars before ending their lives as core-collapse supernovae. our 2d axisymmetric hydrodynamical simulations explore how a fast wind (2000 km s^{-1}) and high mass-loss ... | wind nebulae and supernova remnants of very massive stars |
recent spitzer/infrared array camera (irac) photometric observations have revealed that rest-frame optical emission lines contribute significantly to the broad-band fluxes of high-redshift galaxies. specifically, in the narrow redshift range z ∼ 5.1-5.4 the [3.6]-[4.5] colour is expected to be very red, due to contamin... | mean hα+[n ii]+[s ii] ew inferred for star-forming galaxies atz ∼ 5.1-5.4 using high-qualityspitzer/irac photometry |
an analysis of the type ic supernova (sn) 2004aw is performed by means of models of the photospheric and nebular spectra and of the bolometric light curve. sn 2004aw is shown not to be 'broad-lined', contrary to previous claims, but rather a 'fast-lined' sn ic. the spectral resemblance to the narrow-lined type ic sn 19... | modelling the type ic sn 2004aw: a moderately energetic explosion of a massive c+o star without a grb |
the importance of long-period binaries for the formation and evolution of planetary nebulae is still rather poorly understood, which in part is due to the lack of central star systems that are known to comprise such long-period binaries. here, we report on the latest results from the on-going mercator-hermes survey for... | the long-period binary central stars of the planetary nebulae ngc 1514 and lotr 5 |
we use the pyneb 1.1.16 python package to evaluate the atomic datasets available for the spectral modeling of [fe ii] and [fe iii], which list level energies, a-values, and effective collision strengths. most datasets are reconstructed from the sources, and new ones are incorporated to be compared with observed and mea... | atomic data assessment with pyneb: radiative and electron impact excitation rates for [fe ii] and [fe iii] |
we obtain a magnitude-limited sample of andromeda (m 31) disc pne with chemical abundance estimated through the direct detection of the [o iii] 4363 å line. this leads to 205 and 200 pne with oxygen and argon abundances, respectively. we find that high- and low-extinction m 31 disc pne have statistically distinct argon... | the survey of planetary nebulae in andromeda (m31) - iv. radial oxygen and argon abundance gradients of the thin and thicker disc |
we present and discuss the optical spectrophotometric observations of the nearby (z = 0.087) type i superluminous supernova (slsn i) sn 2017gci, whose peak k-corrected absolute magnitude reaches mg = -21.5 mag. its photometric and spectroscopic evolution includes features of both slow- and of fast-evolving slsn i, thus... | sn 2017gci: a nearby type i superluminous supernova with a bumpy tail |
context. stellar feedback is one of the fundamental factors regulating the evolution of galaxies. however, we still do not have access to strong observational constraints on the relative importance of the different feedback mechanisms (e.g. radiation, ionised gas pressure, stellar winds) in driving h ii region evolutio... | linking stellar populations to h ii regions across nearby galaxies. i. constraining pre-supernova feedback from young clusters in ngc 1672 |
context. anomalies in the abundance measurements of short lived radionuclides in meteorites indicate that the protosolar nebulae was irradiated by a large number of energetic particles (e ≳ 10 mev). the particle flux of the contemporary sun cannot explain these anomalies. however, similar to t tauri stars the young sun... | stellar energetic particle ionization in protoplanetary disks around t tauri stars |
cedrela species occur within the tropical montane cloud forest (tmcf) and rainforest in north america (mexico), central and south america. we assessed the hypothesis that functional xylem hydraulic architecture might be influenced by specific climatic variations. we investigated the effect of climate on tree-ring width... | plastic adjustments in xylem vessel traits to drought events in three cedrela species from peruvian tropical andean forests |
we have used the tidal equations of zahn to determine the maximum orbital distance at which companions are brought into roche lobe contact with their giant primary, when the primary expands during the giant phases. this is a key step when determining the rates of interaction between giants and their companions. our ste... | the effect of tides on the population of pn from interacting binaries |
we present a study of hen 2-155 and hen 2-161, two planetary nebulae which bear striking morphological similarities to other planetary nebulae known to host close-binary central stars. both central stars are revealed to be photometric variables while spectroscopic observations confirm that hen 2-155 is host to a double... | the post-common envelope central stars of the planetary nebulae henize 2-155 and henize 2-161 |
understanding the relationships between and among chondritic components of various chondrite groups is of prime importance for deciphering the dynamics of material transport and planetary accretion in the early solar system. here we obtain insights into these processes and the reservoirs present by investigating the nu... | ti isotopic evidence for a non-cai refractory component in the inner solar system |
we report the detection of co(j=2-1) coincident with the super star cluster (ssc) mrk 71-a in the nearby green pea analog galaxy, ngc 2366. our observations with the northern extended millimeter array reveal a compact, ∼7 pc, molecular cloud whose mass ({10}5 {m}⊙ ) is similar to that of the ssc, consistent with a high... | dense co in mrk 71-a: superwind suppressed in a young super star cluster |
we perform a comprehensive analysis of the redshift evolution of the rest-uv spectra of star-forming galaxies out to z ∼ 5. we combine new z ∼ 5 measurements of h i ly α and low- and high-ionization interstellar metal absorption features with comparable measurements at z ∼ 2-4. we measure the equivalent widths of inter... | the redshift evolution of rest-uv spectroscopic properties to z ∼ 5 |
we revisit previous suggestions that the heating provided by the winds of dying low-mass stars plays an important role in preventing star formation in quiescent galaxies. at the end of their asymptotic giant branch phase, intermediate and low-mass stars eject their envelopes rapidly in a super-wind phase, usually givin... | preventing star formation in early-type galaxies with late-time stellar heating |
distance uncertainties plague our understanding of the physical scales relevant to the physics of star formation in extragalactic studies. the planetary nebulae luminosity function (pnlf) is one of very few techniques that can provide distance estimates to within ∼10% however, it requires a planetary nebula (pn) sample... | a revised planetary nebula luminosity function distance to ngc 628 using muse |
using three independent directions, we estimate that the fraction of type ia supernovae (sne ia) exploding inside planetary nebulae (pne), termed snips, is at least ∼20 per cent. our three directions are: (i) taking the variable sodium absorption lines in some sne ia to originate in massive circum-stellar matter (csm),... | the fraction of type ia supernovae exploding inside planetary nebulae (snips) |
we present observations of a peculiar hydrogen- and helium-poor stripped-envelope (se) supernova (sn) 2020wnt, primarily in the optical and near-infrared (near-ir). its peak absolute bolometric magnitude of -20.9 mag (l bol, peak = (6.8 ± 0.3) × 1043 erg s-1) and a rise time of 69 days are reminiscent of hydrogen-poor ... | supernova 2020wnt: an atypical superluminous supernova with a hidden central engine |
sn 2014j in m 82 is the closest type ia supernova (sn ia) in decades. the proximity allows for detailed studies of supernova physics and provides insights into the circumstellar and interstellar environment. in this work, we analyse spitzer mid-infrared (mid-ir) data of sn 2014j in the 3.6 and 4.5 μm wavelength range, ... | spitzer observations of sn 2014j and properties of mid-ir emission in type ia supernovae |
collisions that induce melting and vaporization can have a substantial effect on the thermal and geochemical evolution of planets. however, the thermodynamics of major minerals are not well known at the extreme conditions attained during planet formation. we obtained new data at the sandia z machine and use published t... | silicate melting and vaporization during rocky planet formation |
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