bluuebunny/crossref_metadata_2025_split huggingface dataset:
The binary central star of the bipolar pre-planetary nebula IRAS 08005−2356 (V510 Pup)
Authors: Manick Rajeev , Miszalski Brent , Kamath Devika , Whitelock Patricia A , Van Winckel Hans , Hrivnak Bruce J , Barlow Brad N , Mohamed Shazrene 
Published: September 2021

ABSTRACT
Current models predict that binary interactions are a major ingredient in the formation of bipolar planetary nebulae (PNe) and pre-planetary nebulae (PPNe). Despite years of radial velocity (RV) monitoring, the paucity of known binaries amongst the latter systems means data are insufficient to examine this relationship in detail. In this work, we report on the discovery of a long-period (P = 2654 ± 124 d) binary at the centre of the Galactic bipolar PPN IRAS 08005−2356 (V510 Pup), determined from long-term spectroscopic and near-infrared time-series data. The spectroscopic orbit is fitted with an eccentricity of 0.36 ± 0.05, which is similar to that of other long-period post-AGB binaries. Time-resolved Hα profiles reveal high-velocity outflows (jets) with deprojected velocities up to 231$_{-27}^{+31}$ km s−1 seen at phases when the luminous primary is behind the jet. The outflow traced by Hα is likely produced via accretion on to a main-sequence companion, for which we calculate a mass of 0.63 ± 0.13 M⊙. This discovery is one of the first cases of a confirmed binary PPN and demonstrates the importance of high-resolution spectroscopic monitoring surveys using large telescopes in revealing binarity among these systems.
Anomalous broad-line region responses to continuum variability in active galactic nuclei – I. Hβ variability
Authors: Gaskell C Martin , Bartel Kayla , Deffner Julia N , Xia Iris 
Published: September 2021

ABSTRACT
In the standard active galactic nucleus (AGN) reverberation-mapping model, variations in broad-line region (BLR) fluxes are predicted from optical continuum variability (taken as a proxy for the ionizing continuum) convolved with a response function that depends on the geometry. However, it has long been known that BLR variability can deviate from these predictions. We analyse both extensive long-term Hβ and continuum monitoring of NGC 5548 and a large sample of high-quality Hβ light curves of other AGNs to investigate the frequency and characteristics of the anomalous responses of the BLR. We find that anomalies are very common and probably occur in every object. Onsets can be on a time-scale only slightly longer than the light-crossing time and durations are of the order of the characteristic time-scale of variability of the optical continuum to several times longer. Anomalies are larger when NGC 5548 is in a low state, but otherwise there is no correlation with continuum variability. There is abundant evidence for the optical continuum of AGNs varying independently of the higher-energy continua and this is sufficient to explain the anomalous responses of the total BLR flux. There are good reasons for believing that the frequent lack of correlation between spectral regions is due to anisotropic and non-axisymmetric emission. Rapid changes in line profiles and velocity-dependent lags are consistent with this. Motion of compact absorbing clouds across the line of sight is another possible cause of anomalies. The prevalence of anomalies should be considered when planning reverberation-mapping campaigns.
JexoSim 2.0: end-to-end JWST simulator for exoplanet spectroscopy – implementation and case studies
Authors: Sarkar Subhajit , Madhusudhan Nikku 
Published: September 2021

ABSTRACT
The recently developed JWST Exoplanet Observation Simulator (JexoSim) simulates transit spectroscopic observations of exoplanets by JWST with each of its four instruments using a time-domain approach. Previously, we reported the validation of JexoSim against Pandexo and instrument team simulators. In the present study, we report a substantially enhanced version, JexoSim 2.0, which improves on the original version through incorporation of new noise sources, enhanced treatment of stellar and planetary signals and instrumental effects, as well as improved user-operability and optimizations for increased speed and efficiency. A near complete set of instrument modes for exoplanet time-series observations is now included. In this paper, we report the implementation of JexoSim 2.0 and assess performance metrics for JWST in end-member scenarios using the hot Jupiter HD 209458 b and the mini-Neptune K2-18 b. We show how JexoSim can be used to compare performance across the different JWST instruments, selecting an optimal combination of instrument and subarray modes, producing synthetic transmission spectra for each planet. These studies indicate that the 1.4 $\mu$m water feature detected in the atmosphere of K2-18 b using the Hubble WFC3 might be observable in just one transit observation with JWST with either NIRISS or NIRSpec. JexoSim 2.0 can be used to investigate the impact of complex noise and systematic effects on the final spectrum, plan observations and test the feasibility of novel science cases for JWST. It can also be customized for other astrophysical applications beyond exoplanet spectroscopy. JexoSim 2.0 is now available for use by the scientific community.
First deep images catalogue of extended IPHAS PNe
Authors: Sabin L , Guerrero M A , Ramos-Larios G , Boumis P , Zijlstra A A , Awang Iskandar D N F , Barlow M J , Toalá J A , Parker Q A , Corradi R M L , Morris R A H 
Published: September 2021

ABSTRACT
We present the first instalment of a deep imaging catalogue containing 58 True, Likely, and Possible extended PNe detected with the Isaac Newton Telescope Photometric H α Survey (IPHAS). The three narrow-band filters in the emission lines of H α, [N ii] λ6584 Å, and [O iii] λ5007 Å used for this purpose allowed us to improve our description of the morphology and dimensions of the nebulae. In some cases even the nature of the source has been reassessed. We were then able to unveil new macro- and micro-structures, which will without a doubt contribute to a more accurate analysis of these PNe. It has been also possible to perform a primary classification of the targets based on their ionization level. A Deep Learning classification tool has also been tested. We expect that all the PNe from the IPHAS catalogue of new extended planetary nebulae will ultimately be part of this deep H α, [N ii], and [O iii] imaging catalogue.
AbacusSummit: a massive set of high-accuracy, high-resolution N-body simulations
Authors: Maksimova Nina A , Garrison Lehman H , Eisenstein Daniel J , Hadzhiyska Boryana , Bose Sownak , Satterthwaite Thomas P 
Published: September 2021

ABSTRACT
We present the public data release of the AbacusSummit cosmological N-body simulation suite, produced with the Abacus N-body code on the Summit supercomputer of the Oak Ridge Leadership Computing Facility. Abacus achieves $\mathcal {O}(10^{-5})$ median fractional force error at superlative speeds, calculating 70M particle updates per second per node at early times, and 45M particle updates per second per node at late times. The simulation suite totals roughly 60 trillion particles, the core of which is a set of 139 simulations with particle mass $2\times 10^{9}\, h^{-1}\, \mathrm{M}_\odot$ in box size $2\, h^{-1}\, \mathrm{Gpc}$. The suite spans 97 cosmological models, including Planck 2018, previous flagship simulation cosmologies, and a linear derivative and cosmic emulator grid. A subsuite of 1883 boxes of size $500\, h^{-1}\, \mathrm{Mpc}$ is available for covariance estimation. AbacusSummit data products span 33 epochs from z = 8 to 0.1 and include light cones, full particle snapshots, halo catalogues, and particle subsets sampled consistently across redshift. AbacusSummit is the largest high-accuracy cosmological N-body data set produced to date.
ALMA and NOEMA constraints on synchrotron nebular emission from embryonic superluminous supernova remnants and radio–gamma-ray connection
Authors: Murase Kohta , Omand Conor M B , Coppejans Deanne L , Nagai Hiroshi , Bower Geoffrey C , Chornock Ryan , Fox Derek B , Kashiyama Kazumi , Law Casey , Margutti Raffaella , Mészáros Peter 
Published: September 2021

ABSTRACT
Fast-rotating pulsars and magnetars have been suggested as the central engines of superluminous supernovae (SLSNe) and fast radio bursts, and this scenario naturally predicts non-thermal synchrotron emission from their nascent pulsar wind nebulae (PWNe). We report results of high-frequency radio observations with ALMA and NOEMA for three SLSNe (SN 2015bn, SN 2016ard, and SN 2017egm), and present a detailed theoretical model to calculate non-thermal emission from PWNe with an age of ∼1−3 yr. We find that the ALMA data disfavours a PWN model motivated by the Crab nebula for SN 2015bn and SN 2017egm, and argue that this tension can be resolved if the nebular magnetization is very high or very low. Such models can be tested by future MeV–GeV gamma-ray telescopes such as AMEGO.
Revisiting the luminosity and redshift distributions of long gamma-ray bursts
Authors: Lan Guang-Xuan , Wei Jun-Jie , Zeng Hou-Dun , Li Ye , Wu Xue-Feng 
Published: September 2021

ABSTRACT
In this work, we update and enlarge the long gamma-ray burst (GRB) sample detected by the Swift satellite. Given the incomplete sampling of the faint bursts and the low completeness in redshift measurement, we carefully select a subsample of bright Swift bursts to revisit the GRB luminosity function (LF) and redshift distribution by taking into account the probability of redshift measurement. Here we also explore two general expressions for the GRB LF, i.e. a broken power-law LF and a triple power-law LF. Our results suggest that a strong redshift evolution in luminosity (with an evolution index of $\delta =1.92^{+0.25}_{-0.37}$) or in density ($\delta =1.26^{+0.33}_{-0.34}$) is required in order to well account for the observations, independent of the assumed expression of the GRB LF. However, in a one-to-one comparison using the Akaike Information Criterion, the best-fitting evolution model involving the triple power-law LF is statistically preferred over the best-fitting one involving the broken power-law LF with a relative probability of ∼94.3 per cent versus ∼5.7 per cent. Extrapolating our fitting results to the flux limit of the whole Swift sample, and considering the trigger probability of Swift/Burst Alert Telescope in detail, we find that the expectations from our evolution models provide a good representation of the observed distributions of the whole sample without the need for any adjustment of the model free parameters. This further confirms the reliability of our analysis results.
Correcting the effect of stellar spots on ARIEL transmission spectra – II. The limb-darkening effect
Authors: Cracchiolo G , Micela G , Morello G , Peres G 
Published: September 2021

ABSTRACT
This paper is part of an effort to correct the transmission spectra of a transiting planet orbiting an active star. In Paper I (Cracchiolo, Micela & Peres 2020), we have demonstrated a methodology to minimize the potential bias induced by unocculted star spots on the transmission spectrum, assuming a spot model parametrized by filling factor and temperature. In this work, we introduce the limb-darkening effect, therefore the position of the spot in the stellar disc and the impact parameter of the transiting planet now play a key role. The method is tested on simulations of planetary transits of three representative kinds of planetary systems, at ARIEL resolution. We find that a realistic treatment of the limb darkening is required to reliably estimate both the spots parameters and the transmission spectrum of the transiting planet. Furthermore, we show that the influence of the spots on the retrieval of the planetary transmission spectrum is significant for spots close to the centre of the star, covering a fraction greater than 0.05 and with a temperature contrast greater than $500\, {\rm K}$, and that for these cases our method can confidently extract the transmission spectrum and the impact parameter of the transiting planet for both cases of occulted and not occulted spots, provided that we have an accurate characterization of the stellar parameters and a reliable simulator of the instrument performances.
Optical detection of the rapidly spinning white dwarf in V1460 Her
Authors: Pelisoli Ingrid , Marsh T R , Ashley R P , Hakala Pasi , Aungwerojwit A , Burdge K , Breedt E , Brown A J , Chanthorn K , Dhillon V S , Dyer M J , Green M J , Kerry P , Littlefair S P , Parsons S G , Sahman D I , Wild J F , Yotthanathong S 
Published: September 2021

ABSTRACT
Accreting magnetic white dwarfs offer an opportunity to understand the interplay between spin-up and spin-down torques in binary systems. Monitoring of the white dwarf spin may reveal whether the white dwarf spin is currently in a state of near-equilibrium, or of unidirectional evolution towards longer or shorter periods, reflecting the recent history of the system and providing constraints for evolutionary models. This makes the monitoring of the spin history of magnetic white dwarfs of high interest. In this paper, we report the results of a campaign of follow-up optical photometry to detect and track the 39- s white dwarf spin pulses recently discovered in Hubble Space Telescope data of the cataclysmic variable V1460 Her. We find the spin pulsations to be present in the g-band photometry at a typical amplitude of 0.4 per cent. Under favourable observing conditions, the spin signal is detectable using 2-m class telescopes. We measured pulse-arrival times for all our observations, which allowed us to derive a precise ephemeris for the white dwarf spin. We have also derived an orbital modulation correction that can be applied to the measurements. With our limited baseline of just over 4 yr, we detect no evidence yet for spin-up or spin-down of the white dwarf, obtaining a lower limit of $|P/\dot{P}| \gt 4\times 10^{7}$ yr, which is already four to eight times longer than the time-scales measured in two other cataclysmic variable systems containing rapidly rotating white dwarfs, AE Aqr and AR Sco.
Velocity dispersion of brightest cluster galaxies in cosmological simulations
Authors: Marini I , Borgani S , Saro A , Granato G L , Ragone-Figueroa C , Sartoris B , Dolag K , Murante G , Ragagnin A , Wang Y 
Published: September 2021

ABSTRACT
Using the DIANOGA hydrodynamical zoom-in simulation set of galaxy clusters, we analyse the dynamics traced by stars belonging to the brightest cluster galaxies (BCGs) and their surrounding diffuse component, forming the intracluster light (ICL), and compare it to the dynamics traced by dark matter and galaxies identified in the simulations. We compute scaling relations between the BCG and cluster velocity dispersions and their corresponding masses (i.e. $M_\mathrm{BCG}^{\star }$–$\sigma _\mathrm{BCG}^{\star }$, M200–σ200, $M_\mathrm{BCG}^{\star }$–M200, and $\sigma _\mathrm{BCG}^{\star }$–σ200), we find in general a good agreement with observational results. Our simulations also predict $\sigma _\mathrm{BCG}^{\star }$–σ200 relation to not change significantly up to redshift z = 1, in line with a relatively slow accretion of the BCG stellar mass at late times. We analyse the main features of the velocity dispersion profiles, as traced by stars, dark matter, and galaxies. As a result, we discuss that observed stellar velocity dispersion profiles in the inner cluster regions are in excellent agreement with simulations. We also report that the slopes of the BCG velocity dispersion profile from simulations agree with what is measured in observations, confirming the existence of a robust correlation between the stellar velocity dispersion slope and the cluster velocity dispersion (thus, cluster mass) when the former is computed within 0.1R500. Our results demonstrate that simulations can correctly describe the dynamics of BCGs and their surrounding stellar envelope, as determined by the past star formation and assembly histories of the most massive galaxies of the Universe.
Collisional excitation of methylene by molecular hydrogen
Authors: Dagdigian Paul J 
Published: September 2021

ABSTRACT
Accurate estimates of the abundance of methylene (CH2) in the interstellar medium require knowledge of both the radiative and collisional rate coefficients for the transfer of population between rotational levels. In this work, time-independent quantum close coupling calculations have been carried out to compute rate coefficients for the (de-)excitation of ortho- and para-CH2 in collisions with ortho- and para-H2. These scattering calculations have employed a recently computed, high-quality potential energy surface, based on the coupled cluster level of theory [RCCSD(T)-F12a], for the interaction of CH2 in its ground $\tilde{X} ^3B_1$ electronic state with H2. The collisional rate coefficients were obtained for all fine-structure transitions among the first 22 and 24 energy levels of ortho- and para-CH2, respectively, having energies less than 277 cm−1. These rate coefficients are compared with previous calculated values, obtained by scaling data for CH2–He. In the case of ortho-CH2, whose levels display hyperfine structure, rate coefficients for transitions between hyperfine levels were also computed, by the MJ randomization approximation. Finally, some simple radiative transfer calculations are presented.
A high-resolution line list for AlO
Authors: Bowesman Charles A , Shuai Meiyin , Yurchenko Sergei N , Tennyson Jonathan 
Published: September 2021

ABSTRACT
Indications of aluminium monoxide in atmospheres of exoplanets are being reported. Studies using high-resolution spectroscopy should allow a strong detection but require high-accuracy laboratory data. A marvel (measured active rotational-vibrational energy levels) analysis is performed for the available spectroscopic data on 27Al16O: 22 473 validated transitions are used to determine 6485 distinct energy levels. These empirical energy levels are used to provide an improved, spectroscopically accurate version of the ExoMol ATP line list for 27Al16O; at the same time, the accuracy of the line lists for the isotopically substituted species 26Al16O, 27Al17O, and 27Al18O is improved by correcting levels in line with the corrections used for 27Al16O. These line lists are available from the ExoMol data base at www.exomol.com.
The functional relation between three-body mean motion resonances and Yarkovsky drift speeds
Authors: Milić Žitnik I 
Published: September 2021

ABSTRACT
We examined the motion of asteroids across the three-body mean motion resonances (MMRs) with Jupiter and Saturn and with the Yarkovsky drift speed in the semimajor axis of the asteroids. The research was conducted using numerical integrations performed using the Orbit9 integrator with 84 000 test asteroids. We calculated time delays, dtr, caused by the seven three-body MMRs on the mobility of test asteroids with 10 positive and 10 negative Yarkovsky drift speeds, which are reliable for Main Belt asteroids. Our final results considered only test asteroids that successfully crossed over the MMRs without close approaches to the planets. We have devised two equations that approximately describe the functional relation between the average time 〈dtr〉 spent in the resonance, the strength of the resonance SR, and the semimajor axis drift speed da/dt (positive and negative) with the orbital eccentricities of asteroids in the range (0, 0.1). Comparing the values of 〈dtr〉 obtained from the numerical integrations and from the derived functional relations, we analysed average values of 〈dtr〉 in all three-body MMRs for every da/dt. The main conclusion is that the analytical and numerical estimates of the average time 〈dtr〉 are in very good agreement, for both positive and negative da/dt. Finally, this study shows that the functional relation we obtain for three-body MMRs is analogous to that previously obtained for two-body MMRs.
Asteroseismic fingerprints of stellar mergers
Authors: Rui Nicholas Z , Fuller Jim 
Published: September 2021

ABSTRACT
Stellar mergers are important processes in stellar evolution, dynamics, and transient science. However, it is difficult to identify merger remnant stars because they cannot easily be distinguished from single stars based on their surface properties. We demonstrate that merger remnants can potentially be identified through asteroseismology of red giant stars using measurements of the gravity mode period spacing together with the asteroseismic mass. For mergers that occur after the formation of a degenerate core, remnant stars have overmassive envelopes relative to their cores, which is manifested asteroseismically by a g-mode period spacing smaller than expected for the star’s mass. Remnants of mergers that occur when the primary is still on the main sequence or whose total mass is less than $\approx \! 2 \, {\rm M}_\odot$ are much harder to distinguish from single stars. Using the red giant asteroseismic catalogues of Vrard, Mosser & Samadi and Yu et al., we identify 24 promising candidates for merger remnant stars. In some cases, merger remnants could also be detectable using only their temperature, luminosity, and asteroseismic mass, a technique that could be applied to a larger population of red giants without a reliable period spacing measurement.
Comptonization by reconnection plasmoids in black hole coronae I: Magnetically dominated pair plasma
Authors: Sridhar Navin , Sironi Lorenzo , Beloborodov Andrei M 
Published: September 2021

ABSTRACT
We perform 2D particle-in-cell simulations of reconnection in magnetically dominated electron–positron plasmas subject to strong Compton cooling. We vary the magnetization σ ≫ 1, defined as the ratio of magnetic tension to plasma inertia, and the strength of cooling losses. Magnetic reconnection under such conditions can operate in magnetically dominated coronae around accreting black holes, which produce hard X-rays through Comptonization of seed soft photons. We find that the particle energy spectrum is dominated by a peak at mildly relativistic energies, which results from bulk motions of cooled plasmoids. The peak has a quasi-Maxwellian shape with an effective temperature of ∼100 keV, which depends only weakly on the flow magnetization and the strength of radiative cooling. The mean bulk energy of the reconnected plasma is roughly independent of σ, whereas the variance is larger for higher magnetizations. The spectra also display a high-energy tail, which receives ∼25 per cent of the dissipated reconnection power for σ = 10 and ∼40 per cent for σ = 40. We complement our particle-in-cell studies with a Monte Carlo simulation of the transfer of seed soft photons through the reconnection layer, and find the escaping X-ray spectrum. The simulation demonstrates that Comptonization is dominated by the bulk motions in the chain of Compton-cooled plasmoids and, for σ ∼ 10, yields a spectrum consistent with the typical hard state of accreting black holes.