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we measure the balmer decrements of 23 of the brightest planetary nebulae (pne) in the inner bulge (r ≲ 3‧) of m31 and deredden the bright end of the region’s [o iii] λ5007 pn luminosity function. we show that the most luminous pne produce ≳1200 l ⊙ of power in their [o iii] λ5007 line, implying central star luminositi... | the true luminosities of planetary nebulae in m31's bulge: massive central stars from an old stellar population |
astrophysical jets are collimated, high-speed outflows observed to be natural features of celestial objects that spin and accrete matter. from protoplanetary nebula and young stellar objects to active galactic nuclei, common features suggest that universal mechanisms may lead to the remarkable straightness observed in ... | helical shear-flow stabilization of an astrophysically relevant laboratory plasma jet |
g21.5-0.9 is a plerionic supernova remnant (snr) used as a calibration target for the chandra x-ray telescope. the first observations found an extended halo surrounding the bright central pulsar wind nebula (pwn). a 2005 study discovered that this halo is limb-brightened and suggested the halo to be the missing snr she... | the deepest chandra x-ray study of the plerionic supernova remnant g21.5-0.9 |
we have used existing optical emission and absorption lines, [c ii] emission lines, and h i absorption lines to create a new model for a central column of material near the trapezium region of the orion nebula. this was necessary because recent high spectral resolution spectra of optical emission lines and imaging spec... | the structure of the orion nebula in the direction of θ 1 ori c |
context. m 105 (ngc 3379) is an early-type galaxy in the leo i group. the leo i group is the nearest group that contains all main galaxy types and can thus be used as a benchmark to study the properties of the intra-group light (igl) in low-mass groups.aims: we present a photometric survey of planetary nebulae (pne) in... | the halo of m 105 and its group environment as traced by planetary nebula populations. i. wide-field photometric survey of planetary nebulae in the leo i group |
it is believed that an isolated pulsar loses its rotational energy mainly through a relativistic wind consisting of electrons, positrons and possibly poynting flux1-3. as it expands, this wind may eventually be terminated by a shock, where particles can be accelerated to energies of x-ray synchrotron emission, and a pu... | the brightening of the pulsar wind nebula of psr b0540-69 after its spin-down-rate transition |
the well-studied carbon star, v hya, showing evidence for high-speed, collimated outflows and dense equatorial structures, is a key object in the study of the poorly understood transition of agb stars into aspherical planetary nebulae. using the space telescope imaging spectrograph instrument on board the hubble space ... | high-speed bullet ejections during the agb-to-planetary nebula transition: hst observations of the carbon star, v hydrae |
the recurrent nova t crb has entered in 2015 a phase of unprecedented high activity. to trace something equivalent, it is necessary to go back to 1938, before the last nova eruption in 1946. the 2015 super-active state is characterized by: a large increase in the mean brightness (δb=0.72 mag over the underlying secular... | the 2015 super-active state of recurrent nova t crb and the long term evolution after the 1946 outburst |
we report on the first measurements of the isotopic ratio 14n/15n in n2h+ toward a statistically significant sample of high-mass star-forming cores. the sources belong to the three main evolutionary categories of the high-mass star formation process: high-mass starless cores, high-mass protostellar objects, and ultraco... | first measurements of 15n fractionation in n2h+ toward high-mass star-forming cores |
an investigation of the iras 16148-5011 region - a cluster at a distance of 3.6 kpc - is presented here, carried out using multiwavelength data in near-infrared (nir) from the 1.4 m infrared survey facility telescope, mid-infrared (mir) from the archival spitzer glimpse (galactic legacy infrared midplane survey extraor... | study of morphology and stellar content of the galactic h ii region iras 16148-5011 |
the detection of neutron(n)-capture elements in several planetary nebulae (pne) has provided a new means of investigating s-process nucleosynthesis in low-mass stars. however, a lack of atomic data has inhibited accurate trans-iron element abundance determinations in astrophysical nebulae. recently, photoionization (pi... | the abundances of light neutron-capture elements in planetary nebulae. iii. the impact of new atomic data on nebular selenium and krypton abundance determinations |
we identify [rb iv] 1.5973 and [cd iv] 1.7204 μm emission lines in high-resolution (r = 40,000) near-infrared spectra of the planetary nebulae (pne) ngc 7027 and ic 5117, obtained with the immersion grating infrared spectrometer (igrins) on the 2.7 m telescope at mcdonald observatory. we also identify [ge vi] 2.1930 μm... | discovery of rubidium, cadmium, and germanium emission lines in the near-infrared spectra of planetary nebulae |
we report the detection of near-ir h2 emission from the low-ionization structures (knots) in two planetary nebulae. the deepest ever high-angular-resolution h2 (1-0) s(1) at 2.122 μm, h2 (2-1) s(1) at 2.248 μm and brγ images of k 4-47 and ngc 7662, obtained using the near infrared imager and spectrometer (niri) at gemi... | h2 in low-ionization structures of planetary nebulae |
dust plays a key role in the formation of planets and its emission also provides one of our most accessible views of protoplanetary discs. if set by radiative equilibrium with the central star, the temperature of dust in the disc plateaus at around 10-20 k in the outer regions. however, sufficiently nearby massive star... | warm millimetre dust in protoplanetary discs near massive stars |
recent detection of exoplanets with earth-like insolation attracts growing interest in how common earth-like aqua planets are beyond the solar system. while terrestrial planets are often assumed to capture icy or water-rich planetesimals, a primordial atmosphere of nebular origin itself can produce water through oxidat... | formation of aqua planets with water of nebular origin: effects of water enrichment on the structure and mass of captured atmospheres of terrestrial planets |
canis major ob1 (cma ob1) is a galactic stellar association with a very intriguing star-formation scenario. there are more than two dozen known star clusters in its line of sight, but it is not clear which ones are physically associated with cma ob1. we use a clustering code that employs five-dimensional data from the ... | canis major ob1 stellar group contents revealed by gaia |
the crab nebula is a supernova remnant exhibiting a highly polarized synchrotron radiation at radio and millimetre wavelengths. it is the brightest source in the microwave sky with an extension of 7 by 5 arcmin, and is commonly used as a standard candle for any experiment which aims to measure the polarization of the s... | nika 150 ghz polarization observations of the crab nebula and its spectral energy distribution |
although fullerenes have long been hypothesized to occur in interstellar environments, they have only recently been unambiguously identified through spectroscopy1-4. c60, c70 and c60+ now constitute the largest molecular species individually identified in the interstellar medium. fullerenes have substantial proton affi... | the infrared spectrum of protonated buckminsterfullerene c60h+ |
in the hierarchical model of structure formation, giant elliptical galaxies form through merging processes within the highest density peaks known as protoclusters. while high-redshift radio galaxies usually pinpoint the location of these environments, we have recently discovered at z ∼ 2-3 three enormous (> 200 kpc)... | overdensity of submillimeter galaxies around the z ≃ 2.3 mammoth-1 nebula. the environment and powering of an enormous lyman-α nebula |
the ic iron meteorite group is characterized utilizing nucleosynthetic mass-independent isotopic compositions and 182w age constraints, coupled with siderophile element concentration measurements and modeling of crystal-liquid fractionation processes. the six ic irons analyzed, arispe, bendego, chihuahua city, nocolech... | genetics, age, and crystallization history of group ic iron meteorites |
the gravitational force controls the evolution of the universe on several scales. it is responsible for the formation of galaxies from the primordial matter distribution and the formation of planets from solar nebulae. because the gravitational force is singular and has infinite range, making predictions based on fully... | from chaos to cosmology: insights gained from 1d gravity |
context after decades of political and economic isolation, myanmar is now the focus of large international investments, particularly from china, which raises questions of how to balance national development with safeguarding the indo-burma biodiversity hotspot. objective to evaluate the impact of five major development... | simulating the impact of belt and road initiative and other major developments in myanmar on an ambassador felid, the clouded leopard, neofelis nebulosa |
three-dimensional (3d) structure-based tin disulfide/vertically aligned carbon nanotube arrays (vacnts) composites have been successfully fabricated via a facile hydrothermal method for self-assembly with the help of nebulization-assisted infiltration. the sns2 particles are anchored on the surface of the vacnts and th... | three-dimensional structure-based tin disulfide/vertically aligned carbon nanotube arrays composites as high-performance anode materials for lithium ion batteries |
we have measured astrometry for members of the orion nebula cluster with images obtained in 2015 with the wide field camera 3 on board the hubble space telescope. by comparing those data to previous measurements with the near-infrared camera and multi-object spectrometer on hubble in 1998, we have discovered that a sta... | new evidence for the dynamical decay of a multiple system in the orion kleinmann-low nebula |
the amount of atmospheric gas absorbed into a planetary interior during formation depends on the temperature, pressure, composition, and dynamics of its atmosphere, along with the planet mass, its composition, rate of accretion, and the average age of its surface. we develop a boundary layer model for terrestrial plane... | hydrogen and helium ingassing during terrestrial planet accretion |
we present the results of two-dimensional hydrodynamic simulations of self-gravitating circumbinary discs around binaries whose parameters match those of the circumbinary planet-hosting systems kepler-16, kepler-34 and kepler-35. previous work has shown that non-self-gravitating discs in these systems form an eccentric... | the role of disc self-gravity in circumbinary planet systems - i. disc structure and evolution |
aims: we aim to identify bipolar galactic h ii regions and to understand their parental cloud structures, morphologies, evolution, and impact on the formation of new generations of stars.methods: we use the spitzer-glimpse, spitzer-mipsgal, and herschel-hi-gal surveys to identify bipolar h ii regions and to examine the... | bipolar h ii regions. ii. morphologies and star formation in their vicinities |
the nebular-epoch spectrum of the rapidly declining, `transitional' type ia supernova (sn) 2007on showed double emission peaks, which have been interpreted as indicating that the sn was the result of the direct collision of two white dwarfs. the spectrum can be reproduced using two distinct emission components, one red... | the nebular spectra of the transitional type ia supernovae 2007on and 2011iv: broad, multiple components indicate aspherical explosion cores |
the hard x-ray imager (hxi) is one of the instruments onboard the astro-h mission [1-4] to be launched in early 2016. the hxi is the focal plane detector of the hard x-ray reflecting telescope that covers an energy range from 5 to 80 kev. it will execute observations of astronomical objects with a sensitivity for point... | the si/cdte semiconductor camera of the astro-h hard x-ray imager (hxi) |
the role of major mergers in galaxy evolution is investigated through a detailed characterization of the stellar populations, ionized gas properties and star formation rates (sfr) in the early-stage merger luminous infrared galaxies (lirgs) ic 1623 w and ngc 6090, by analysing optical integral field spectroscopy and hi... | star formation histories in mergers: the spatially resolved properties of the early-stage merger luminous infrared galaxies ic 1623 and ngc 6090 |
we construct a suite of discrete chemo-dynamical models of the giant elliptical galaxy ngc 5846. these models are a powerful tool to constrain both the mass distribution and internal dynamics of multiple tracer populations. we use jeans models to simultaneously fit stellar kinematics within the effective radius re, pla... | a discrete chemo-dynamical model of the giant elliptical galaxy ngc 5846: dark matter fraction, internal rotation, and velocity anisotropy out to six effective radii |
we have investigated the quadruple sulfur isotopic composition of inorganic sulfur-bearing phases from 13 carbonaceous chondrites of cm type. our samples include 4 falls and 9 antarctic finds. we extracted sulfur from sulfides, sulfates, and elemental sulfur (s0) from all samples. on average, we recover a bulk sulfur (... | mass independent sulfur isotope signatures in cms: implications for sulfur chemistry in the early solar system |
we propose that cosmic ray pevatrons are pulsar wind nebulae (pwne) inside supernova remnants (snrs). the pwn initially expands into the freely expanding stellar ejecta. then, the pwn catches up with the shocked region of the snr, where particles can be slightly accelerated by the back and forth motion between the pwn ... | pulsar wind nebulae inside supernova remnants as cosmic-ray pevatrons |
we present non-lte (non-local-thermodynamic-equilibrium) time-dependent radiative transfer simulations for ejecta produced by the detonation of a helium shell at the surface of a low-mass carbon/oxygen white dwarf (wd). this mechanism is one possible origin for supernovae (sne) with faint and fast-decaying light curves... | one-dimensional non-lte time-dependent radiative transfer of an he-detonation model and the connection to faint and fast-decaying supernovae |
using star-forming galaxies sample in the nearby universe (0.02 < z < 0.10) selected from the sloan digital sky survey (dr7) and galaxy evolution explorer all-sky survey (gr5), we present a new empirical calibration for predicting dust extinction of galaxies from the hα-to-fuv flux ratio. we find that the hα dust... | predicting dust extinction properties of star-forming galaxies from hα/uv ratio |
we present optical and near-infrared observations of sn~2022crv, a stripped envelope supernova in ngc~3054, discovered within 12 hrs of explosion by the distance less than 40 mpc survey. we suggest sn~2022crv is a transitional object on the continuum between sne ib and sne iib. a high-velocity hydrogen feature ($\sim$$... | sn 2022crv: iib, or not iib: that is the question |
hess j1809-193 is an extended tev γ-ray source and the origin of its γ-ray emission remains ambiguous. the pulsar wind nebula (pwn) of psr j1j1809-193 lying inside the extended γ-ray emission is a possible candidate. powered by the central pulsar, ultrarelativistic electrons in the pwn can produce radio to x-ray emissi... | revisiting the chandra observation on the region of psr j1809-193: indication of the existence of an x-ray halo and implication for the origin of hess j1809-193 |
we present design considerations for the transiting exosatellites, moons, and planets in orion (tempo) survey with the nancy grace roman space telescope. this proposed 30 days survey is designed to detect a population of transiting extrasolar satellites, moons, and planets in the orion nebula cluster (onc). the young (... | the tempo survey. i. predicting yields of transiting exosatellites, moons, and planets from a 30 days survey of orion with the roman space telescope |
x-ray polarization from the imaging x-ray polarimetry explorer (ixpe) provides an important new probe of the geometry of the pulsar emission zone and of particle acceleration in the surrounding pulsar wind nebula. however, with ixpe's modest ~20″-30″ spatial resolution, separation of the pulsar signal from the nebula i... | improved measurements of the ixpe crab polarization |
the presence of carbon-chain molecules in the interstellar medium (ism) has been known since the early 1970s and $>100$ such species have been identified to date, making up $>40\%$ of the total of detected ism molecules. they are prevalent not only in star-forming regions in our galaxy but also in other galaxies.... | carbon-chain chemistry in the interstellar medium |
we use rapidly cooled achondrites to test the assumption of 26 al homogeneity in the solar nebula, by checking if there is a single value of tss, the absolute "pb-pb" age of the solar system's t = 0 , that makes concordant their ages from the al-mg and pb-pb systems. we find that values tss = 4568 . 42 ± 0 . 24 myr do ... | statistical chronometry of meteorites. i. a test of 26al homogeneity and the pb-pb age of the solar system's t = 0 |
we describe a revised procedure for the numerical simulation of planetary nebulae luminosity functions (pnlfs), improving on previous work. the procedure is now based on new h-burning post-asymptotic giant branch (agb) evolutionary tracks. for a given stellar mass, the new central stars are more luminous and evolve fas... | revised simulations of the planetary nebulae luminosity function |
most massive stars exchange mass with a companion, leading to evolution which is altered drastically from that expected of stars in isolation. such systems result from unusual binary evolution pathways and can place stringent constraints on the physics of these interactions. we use the r4 binary system's b[e] supergian... | the art of modeling stellar mergers and the case of the b[e] supergiant r4 in the small magellanic cloud |
this paper presents data and analysis of sn 2010kd, a low-redshift (z = 0.101) h-deficient superluminous supernova (slsn), based on ultraviolet/optical photometry and optical spectroscopy spanning between -28 and +194 days relative to b-band maximum light. the b-band light-curve comparison of sn 2010kd with a subset of... | sn 2010kd: photometric and spectroscopic analysis of a slow-decaying superluminous supernova |
we present a model for magnetic energy dissipation in a pulsar wind nebula. a better understanding of this process is required to assess the likelihood that certain astrophysical transients may be powered by the spin-down of a “millisecond magnetar.” examples include superluminous supernovae, gamma-ray bursts, and anti... | turbulent magnetic relaxation in pulsar wind nebulae |
we present a comparative study of the near-infrared (nir) h2 line emission from five regions near hot young stars: sharpless 140, ngc 2023, ic 63, the horsehead nebula, and the orion bar. this emission originates in photodissociation or photon-dominated regions (pdrs), interfaces between photoionized and molecular gas ... | a near-infrared survey of uv-excited molecular hydrogen in photodissociation regions |
the galactic b[e] supergiant mwc 137 is surrounded by a large-scale optical nebula. to shed light on the physical conditions and kinematics of the nebula, we analyze the optical forbidden emission lines [n ii] λλ 6548,6583 and [s ii] λλ 6716,6731 in long-slit spectra taken with alfosc at the nordic optical telescope. t... | resolving the circumstellar environment of the galactic b[e] supergiant star mwc 137.ii. nebular kinematics and stellar variability |
the common envelope phase was first proposed more than 40 years ago to explain the origins of evolved, close binaries like cataclysmic variables. it is now believed that the phase plays a critical role in the formation of a wide variety of other phenomena ranging from type ia supernovae through to binary black holes, w... | observational constraints on the common envelope phase |
wolf-rayet stars are amongst the rarest but also most intriguing massive stars. their extreme stellar winds induce famous multiwavelength circumstellar gas nebulae of various morphologies, spanning from circles and rings to bipolar shapes. this study is devoted to the investigation of the formation of young, asymmetric... | on the bipolarity of wolf-rayet nebulae |
wolf-rayet ([wr]) and weak-emission-line (wels) central stars of planetary nebulae (pns) have hydrogen-deficient atmospheres, whose origins are not well understood. in the present study, we have conducted plasma diagnostics and abundance analyses of 18 galactic pns surrounding [wr] and wels nuclei, using collisionally ... | physical and chemical properties of wolf-rayet planetary nebulae |
we present results on the nature of extreme ejective feedback episodes and the physical conditions of a population of massive (m * ~ 1011 m ⊙), compact starburst galaxies at z = 0.4-0.7. we use data from keck/nirspec, sdss, gemini/gmos, mmt, and magellan/mage to measure rest-frame optical and near-ir spectra of 14 star... | physical properties of massive compact starburst galaxies with extreme outflows |
context. the nucleus of the planetary nebula hen 2-428 is a short orbital-period (4.2 h), double-lined spectroscopic binary, whose status as a potential supernova type ia progenitor has raised some controversy in the literature.aims: with the aim of resolving this debate, we carried out an in-depth reanalysis of the sy... | an in-depth reanalysis of the alleged type ia supernova progenitor henize 2-428 |
ultraluminous infrared galaxies (ulirgs) represent a critical stage in the merger-driven evolution of galaxies when active galactic nucleus (agn) activity is common and agn feedback is expected. we present high-sensitivity and large field-of-view integral field spectroscopy of the ulirg mrk 273 using new data from the ... | kcwi observations of the extended nebulae in mrk 273 |
the relation between the progenitor mass and the kinetic energy of the explosion is a key toward revealing the explosion mechanism of stripped-envelope core-collapse supernovae (sesne). here, we present a method to derive this relation using the nebular spectra of sesne, based on the correlation between [o i]/[ca ii], ... | inferring the progenitor mass-kinetic energy relation of stripped-envelope core-collapse supernovae from nebular spectroscopy |
lyα emission nebulae are ubiquitous around high-redshift galaxies and are tracers of the gaseous environment on scales out to ≳100 pkpc (proper kiloparsec). high-redshift radio galaxies (hzrgs, type-2 radio-loud quasars) host large-scale nebulae observed in the ionised gas differ from those seen in other types of high-... | 3d tomography of the giant lyα nebulae of z ≈ 3-5 radio-loud agn |
aims: we present a non-parametric morphology analysis of the stellar continuum and nebular emission lines for a sample of local galaxies. we explore the dependence of the various morphological parameters on wavelength and morphological type. our goal is to quantify the difference in morphology between the stellar and n... | non-parametric galaxy morphology from stellar and nebular emission with the califa sample |
context. mass and angular momentum are key parameters of galaxies. their coevolution establishes an empirical relation between the specific stellar angular momentum j* and the stellar mass m* that depends on morphology.aims: for this work, we measured j* in a sample of 32 early-type galaxies (etgs) from the epn.s surve... | the extended planetary nebula spectrograph (epn.s) early-type galaxy survey: the specific angular momentum of etgs |
nearly all intragroup (igl) and intracluster light (icl) comes from stars that are not bound to any single galaxy but were formed in galaxies and later unbound from them. in this review we focus on the physical properties - phase space distribution, metallicity and age - of the icl and igl component of the clusters/gro... | kinematics of the diffuse intragroup/intracluster light in groups and clusters of galaxies in the local universe (within 100 mpc distance) |
unbiased sky background modeling is crucial for the analysis of deep wide-field images, but it remains a major challenge in low surface brightness astronomy. traditional image processing algorithms are often designed to produce artificially flat backgrounds, erasing astrophysically meaningful structures. in this paper,... | a recipe for unbiased background modeling in deep wide-field astronomical images |
nebular emission lines are powerful diagnostics for the physical processes at play in galaxy formation and evolution. moreover, emission-line galaxies (elgs) are one of the main targets of current and forthcoming spectroscopic cosmological surveys. we investigate the contributions to the line luminosity functions (lfs)... | characterizing the elg luminosity functions in the nearby universe |
we present atacama large millimeter/sub-millimeter array neutral carbon, [${\rm c\, \small {\rm i}}$](1-0), line observations that probe molecular hydrogen gas (h2) within seven radio galaxies at z = 2.9-4.5 surrounded by extended (≳100 kpc) ly α nebulae. we extract [${\rm c\, \small {\rm i}}$](1-0) emission from the r... | faint [c i](1-0) emission in z 3.5 radio galaxies |
late-time spectra of type ia supernovae (sne ia) are important in clarifying the physics of their explosions, as they provide key clues to the inner structure of the exploding white dwarfs. we examined late-time optical spectra of 36 sne ia, including five from our own project (sne 2019np, 2019ein, 2021hpr, 2021wuf, an... | implications for the explosion mechanism of type ia supernovae from their late-time spectra |
b[e] stars are massive b type emission line stars in different evolutionary stages ranging from pre-main sequence to post-main sequence. due to their mass loss and ejection events these objects deposit huge amounts of mass and energy into their environment and enrich it with chemically processed material, contributing ... | follow-up of extended shells around b[e] stars |
jwst near infrared camera (nircam) observations at 1.5-4.5 μm have provided broadband and narrowband imaging of the evolving remnant of sn 1987a with unparalleled sensitivity and spatial resolution. comparing with previous marginally spatially resolved spitzer infrared array camera (irac) observations from 2004 to 2019... | jwst nircam observations of sn 1987a: spitzer comparison and spectral decomposition |
we present the first spectroscopic measurement of multiple rest-frame optical emission lines at z > 4. during the mosfire deep evolution field survey, we observed the galaxy goodsn-17940 with the keck i/mosfire spectrograph. the k-band spectrum of goodsn-17940 includes significant detections of the [o ii]λλ3726,3729... | the mosdef survey: first measurement of nebular oxygen abundance at z > 4 |
we present the spectral and spatial evolution of h2o masers associated with the water fountain source iras 18043-2116, found in observations with the nobeyama 45 m telescope and the australia telescope compact array. we have found new highest-velocity components of the h2o masers (at the redshifted side v lsr ≃ 376 km ... | evolution of the outflow in the water fountain source iras 18043-2116 |
the origin of volatiles on earth is still a matter of debate. noble gases are an efficient geochemical tool to constrain earth formation processes due to their inertness. several studies have focused on the neon isotopic composition of the lower mantle because the 20ne/22ne ratio is thought to reflect that of earth's p... | neon isotopic composition of the mantle constrained by single vesicle analyses |
iron is the most abundant multivalent element in planetary reservoirs, meaning its isotope composition (expressed as δ57fe) may record signatures of processes that occurred during the formation and subsequent differentiation of the terrestrial planets. chondritic meteorites, putative constituents of the planets and rem... | on the iron isotope composition of mars and volatile depletion in the terrestrial planets |
as shown by broadband observations, pulsar wind nebulae (pwne) are characterized by a broken power-law spectrum of synchrotron emission. based on modern magnetohydrodynamic (mhd) turbulence theories, we investigate the reacceleration of electrons in the pwn through the adiabatic stochastic acceleration (asa), which ari... | on the broadband synchrotron spectra of pulsar wind nebulae |
arcuate infrared nebulae are ubiquitous throughout the galactic plane and are candidates for partial shells, bubbles, or bowshocks produced by massive runaway stars. we tabulate infrared photometry for 709 such objects using images from the spitzer space telescope, the wide-field infrared explorer, and the herschel spa... | infrared photometric properties of 709 candidate stellar bowshock nebulae |
current detectors for very-high-energy γ-ray astrophysics are either pointing instruments with a small field of view (cherenkov telescopes), or large field-of-view instruments with relatively large energy thresholds (extensive air shower detectors). in this article, we propose a new hybrid extensive air shower detector... | design and expected performance of a novel hybrid detector for very-high-energy gamma-ray astrophysics |
how and when earth's volatile content was established is controversial with several mechanisms postulated, including planetesimal evaporation, core formation and the late delivery of undifferentiated chondrite-like materials. the isotopes of volatile elements such as sulfur can be fractionated during planetary accretio... | sulfur isotopic signature of earth established by planetesimal volatile evaporation |
we present adaptive optics assisted near-ir integral field spectroscopic observations of a luminous quasar at z = 2.4, previously observed as the first known example at high redshift of large-scale quasar-driven outflow quenching star formation in its host galaxy. the nuclear spectrum shows broad and blueshifted hβ in ... | an ultra-dense fast outflow in a quasar at z = 2.4 |
we decompose the observed 7.7 μm polycyclic aromatic hydrocarbon (pah) emission complexes in a large sample of over 7000 mid-infrared spectra of the interstellar medium using spectral cubes observed with the spitzer/irs-sl instrument. in order to fit the 7.7 μm pah emission complex we invoke four gaussian components, w... | polycyclic aromatic hydrocarbon emission in spitzer/irs maps. ii. a direct link between band profiles and the radiation field strength |
calcium-rich supernovae (sne) represent a significant challenge for our understanding of the fates of stellar systems. they are less luminous than other sn types and they evolve more rapidly to reveal nebular spectra dominated by strong calcium lines with weak or absent signatures of other intermediate- and iron-group ... | hubble space telescope observations of the host galaxies and environments of calcium-rich supernovae |
the high altitude water cherenkov (hawc) collaboration recently published their 2hwc catalog, listing 39 very high energy (vhe; >100 gev) gamma-ray sources based on 507 days of observation. among these, 19 sources are not associated with previously known teraelectronvolt (tev) gamma-ray sources. we have studied 14 o... | veritas and fermi-lat observations of tev gamma-ray sources discovered by hawc in the 2hwc catalog |
we have investigated the tukh122 prestellar core in the orion a cloud using alma 3 mm dust continuum, n2h+ (j = 1-0), and ch3oh ({j}k={2}k-{1}k) molecular-line observations. previous studies showed that tukh122 is likely on the verge of star formation because the turbulence is almost dissipated and chemically evolved a... | gravitationally unstable condensations revealed by alma in the tukh122 prestellar core in the orion a cloud |
isotopic anomalies in chondrules hold important clues about the dynamics of mixing and transport processes in the solar accretion disk. the meaning of these anomalies is debated and they have been interpreted to indicate either disk-wide transport of chondrules or local heterogeneities of chondrule precursors. however,... | early evolution of the solar accretion disk inferred from cr-ti-o isotopes in individual chondrules |
h.e.s.s. has recently completed the first systematic survey of the galactic plane in the tev energy domain. we analyze the flux, latitude, and longitude distributions of γ-ray sources observed by h.e.s.s. in order to infer the properties of the galactic tev source population. we show that the total milky way luminosity... | the tev gamma-ray luminosity of the milky way and the contribution of h.e.s.s. unresolved sources to very high energy diffuse emission |
in high-energy astronomy, spectro-imaging instruments such as x-ray detectors allow investigation of the spatial and spectral properties of extended sources including galaxy clusters, galaxies, diffuse interstellar medium, supernova remnants, and pulsar wind nebulae. in these sources, each physical component possesses ... | novel method for component separation of extended sources in x-ray astronomy |
with both nebular- and stellar-derived abundances of ≲1/10 z_{⊙ } and low foreground extinction, sextans a is a prime candidate to replace the small magellanic cloud as reservoir of metal-poor massive stars and reference to study the metal-poor universe. we report the discovery of two early o-type stars in sextans a, t... | ongoing star formation at the outskirts of sextans a: spectroscopic detection of early o-type stars |
luminous type-2 quasars in which the glow from the central black hole is obscured by dust are ideal targets for studying their host galaxies and the quasars' effect on galaxy evolution. such feedback appears ubiquitous in luminous obscured quasars where high-velocity-ionized nebulae have been found. we present rest-fra... | towards a comprehensive picture of powerful quasars, their host galaxies and quasar winds at z ∼ 0.5 |
context. the galaxy m 49 (ngc 4472) is the brightest early-type galaxy in the virgo cluster. it is located in subcluster b and has an unusually blue, metal-poor outer halo. planetary nebulae (pne) are excellent tracers of diffuse galaxy and intragroup light (igl).aims: we aim to present a photometric survey of pne in t... | the halo of m 49 and its environment as traced by planetary nebulae populations |
we present the hr-pypopstar model, which provides a complete set (in ages) of high-resolution (hr) spectral energy distributions of single stellar populations. the model uses the most recent high-wavelength-resolution theoretical atmosphere libraries for main-sequence, post-agb/planetary nebulae and wolf-rayet stars. t... | hr-pypopstar: high-wavelength-resolution stellar populations evolutionary synthesis model |
we present an analysis of the effect of feedback from o- and b-type stars with data from the integral field spectrograph multi unit spectroscopic explorer (muse) mounted on the very large telescope of pillar-like structures in the carina nebular complex, one of the most massive star-forming regions in the galaxy. for t... | connecting the dots: a correlation between ionizing radiation and cloud mass-loss rate traced by optical integral field spectroscopy |
aims: we present muffit, a new generic code optimized to retrieve the main stellar population parameters of galaxies in photometric multi-filter surveys, and check its reliability and feasibility with real galaxy data from the alhambra survey.methods: making use of an error-weighted χ2-test, we compare the multi-filter... | stellar populations of galaxies in the alhambra survey up to z ~ 1. i. muffit: a multi-filter fitting code for stellar population diagnostics |
context. vista variables in the vía láctea is an eso public survey dedicated to scanning the bulge and an adjacent portion of the galactic disk in the fourth quadrant using the vista telescope and its near-infrared camera vircam. one of the leading goals of the vvv survey is to contribute to knowledge of the star clust... | hundreds of new cluster candidates in the vista variables in the vía láctea survey dr1 |
the orion a molecular cloud is one of the most well-studied nearby star-forming regions, and includes regions of both highly clustered and more dispersed star formation across its full extent. here, we analyze dense, star-forming cores identified in the 850 and 450 μm scuba-2 maps from the jcmt gould belt legacy survey... | the jcmt gould belt survey: dense core clusters in orion a |
we study the hypothesis of high-metallicity clumps being responsible for the abundance discrepancy found in planetary nebulae between the values obtained from recombination and collisionally excited lines. we generate grids of photoionization models combining cold metal-rich clumps emitting the heavy element recombinat... | bi-abundance photoionization models of planetary nebulae: determining the amount of oxygen in the metal-rich component |
sn 2017eaw, the tenth supernova observed in ngc 6946, was a normal type ii-p supernova with an estimated 11-13 m⊙ red supergiant progenitor. here we present nebular-phase spectra of sn 2017eaw at +545 and +900 days post-max, extending approximately 50-400 days past the epochs of previously published spectra. while the ... | late-time circumstellar interaction of sn 2017eaw in ngc 6946 |
one of the key methods for determining the unknown nature of type ia supernovae (sne ia) is the search for traces of interaction between the sn ejecta and the circumstellar structures at the resulting supernova remnants (snrs ia). so far, the observables that we receive from well-studied snrs ia cannot be explained sel... | the interaction of type ia supernovae with planetary nebulae: the case of kepler's supernova remnant |
we calculate the decay width of the photon splitting into three photons in a model of quantum electrodynamics with broken lorentz invariance. we show that this process can lead to a cut-off in the very-high-energy part of a photon spectra of astrophysical sources. we obtain the 95% cl bound on the lorentz violating mas... | photon splitting constraint on lorentz invariance violation from crab nebula spectrum |
we present the discovery and interpretation of ionized nebulae around two ultraluminous x-ray sources in m 51; both sources share the rare property of showing x-ray eclipses by their companion stars and are therefore prime targets for follow-up studies. using archival hubble space telescope images, we found an elongate... | multiband counterparts of two eclipsing ultraluminous x-ray sources in m 51 |
our cycle 0 alma observations confirmed that the boomerang nebula is the coldest known object in the universe, with a massive high-speed outflow that has cooled significantly below the cosmic background temperature. our new co 1-0 data reveal heretofore unseen distant regions of this ultra-cold outflow, out to ≳120,000... | the coldest place in the universe: probing the ultra-cold outflow and dusty disk in the boomerang nebula |
context. the structure of the wind from the cool giants in symbiotic binaries carries important information for understanding the wind mass transfer to their white dwarf companions, its fuelling, and thus the path towards different phases of symbiotic-star evolution.aims: in this paper, we indicate a non-spherical dist... | wind mass transfer in s-type symbiotic binaries. iii. confirmation of a wind focusing in eg andromedae from the nebular [o iii] λ5007 line |
the int galactic plane survey (igaps) is the merger of the optical photometric surveys iphas and uvex based on data from the isaac newton telescope (int) obtained between 2003 and 2018. it captures the entire northern galactic plane within the galactic coordinate range |b|< 5° and 30° < ℓ < 215°. from the begi... | high-resolution hα imaging of the northern galactic plane and the igaps image database |
in this work, we propose two convolutional neural network classifiers for detecting contaminants in astronomical images. once trained, our classifiers are able to identify various contaminants, such as cosmic rays, hot and bad pixels, persistence effects, satellite or plane trails, residual fringe patterns, nebulous fe... | maximask and maxitrack: two new tools for identifying contaminants in astronomical images using convolutional neural networks |
we present new karl g. jansky very large array (vla, 1.5 ghz) radio data for the giant elliptical galaxy ic 4296, supported by archival radio, x-ray (chandra, and xmm-newton) and optical (soar, and hst) observations. the galaxy hosts powerful radio jets piercing through the inner hot x-ray emitting atmosphere, depositi... | powerful agn jets and unbalanced cooling in the hot atmosphere of ic 4296 |
context. hydrogenated amorphous carbons (a-c:h) are a major component of the carbonaceous solids present in the interstellar medium. the production and existence of these grains is connected in particular with the balance between their photolysis, radiolysis, and hydrogenation. during grain processing, h2 and other sma... | vacuum ultraviolet of hydrogenated amorphous carbons. ii. small hydrocarbons production in photon dominated regions |
water fountains are evolved stars showing early stages of collimated mass-loss during transition from the asymptotic giant branch, providing valuable insight into the formation of asymmetric planetary nebulae. we report the results of multi-epoch vlbi observations, which determine the spatial and three-dimensional kine... | rapidly evolving episodic outflow in iras 18113-2503: clues to the ejection mechanism of the fastest water fountain |
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