bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling the light curve of Type IIn-P SN 2005cl with red supergiant progenitors featuring pre-SN outbursts
Authors: Li Chunhui , Morozova Viktoriya 
Published: July 2022

ABSTRACT
All Type IIn supernovae (SNe IIn) show narrow hydrogen emission lines in their spectra. Apart from this common feature, they demonstrate very broad diversity in brightness, duration, and morphology of their light curves, which indicates that they likely come from a variety of progenitor systems and explosion channels. A particular subset of SNe IIn, the so-called SNe IIn-P, exhibit ∼100 d plateau phases that are very similar to the ones of the ordinary hydrogen-rich SNe (SNe II). In the past, SNe IIn-P were explained by the models of sub-energetic electron capture explosions surrounded by dense extended winds. In this work, we attempt to explain this class of SNe with standard red supergiant progenitors that experience outbursts several months before the final explosion. The outburst energies that show the best agreement between our models and the data ($5\times 10^{46}\, {\rm erg}$) fall at the low range of the outburst energies that have been observed for SNe IIn (between few times $10^{46}\, {\rm erg}$ and $10^{49}\, {\rm erg}$). Instead, the inferred explosion energy of SN 2005cl is relatively high ($1{-}2\times 10^{51}\, {\rm erg}$) compared to the explosion energies of the ordinary SNe II. Our models provide alternative explanation of SNe IIn-P to the previously proposed scenarios.
Observability of forming planets and their circumplanetary discs – IV. With JWST and ELT
Authors: Chen Xueqing , Szulágyi Judit 
Published: July 2022

ABSTRACT
To understand the potential for observing forming planets and their circumplanetary discs (CPDs) with James Webb Space Telescope (JWST) and Extremely Large Telescope (ELT), we created mock observations from three-dimensional radiative hydrodynamic simulations and radiative transfer post-processing for planets with 10, 5, and 1 Jupiter and 1 Saturn masses with orbital separation of 50 and 30 au in 0, 30, and 60○ inclinations. Instrumental effects were then simulated with Mirage for JWST/NIRCam and NIRISS, MIRISim for JWST/MIRI, and SimCADO and SimMETIS for ELT/MICADO and METIS. We found that the longer wavelengths (mid-infrared and beyond) are the best to detect CPDs, since they allow CPD of planet with smaller mass to be detected. MIRI on JWST and METIS on ELT offer the best possibility on these telescopes. Specifically, below 3 $\mu{\rm m}$, only 10 MJup planets with their CPDs are detectable with NIRCam and MICADO. 5 MJup planets are only detectable if at 30 au (i.e. closer) orbital separation. Planets above 5 MJup with their CPDs are detectable between 3 and 5 $\mu{\rm m}$ with NIRCam and METIS L/M band, or above 10 $\mu{\rm m}$ with MIRI and METIS N band. For ≤1 MJup planets &gt;15 $\mu{\rm m}$ are needed, where MIRI uniquely offers imaging capability. We present magnitudes and spectral energy distributions for separate components of the planet + CPD + circumstellar disc (CSD) system, to differentiate the extinction rates of CPDs and CSDs and to provide predictions for observational proposals. Because the CPD turns out to be the main absorber of the planet’s emission, especially &lt;10 $\mu{\rm m}$, this makes the detection of forming planets quite challenging.
Extragalactic transient candidates in the second Swift-XRT point source catalogue
Authors: Eyles-Ferris R A J , Starling R L C , O’Brien P T , Evans P A 
Published: July 2022

ABSTRACT
The second Swift-XRT Point Source catalogue offers a combination of sky coverage and sensitivity and presents an invaluable opportunity for transient discovery. We search the catalogue at the positions of inactive and active galaxies, and identify transient candidates by comparison with XMM–Newton and ROSAT. We recover 167 previously known transients and find 19 sources consistent with being new sources, estimating a completeness of $\sim 65{{\ \rm per\ cent}}$. These 19 new sources are split approximately equally between inactive and active hosts and their peak X-ray luminosities span ∼1042–1047 erg s−1. We find eight are best fit with non-thermal spectral models and one with a blackbody. We also discuss our methodology and its application to the forthcoming Living Swift-XRT Point Source catalogue for the potential near real time serendipitous discovery of ∼few new X-ray transients per year.
Realistic 3D hydrodynamics simulations find significant turbulent entrainment in massive stars
Authors: Rizzuti F , Hirschi R , Georgy C , Arnett W D , Meakin C , Murphy A StJ 
Published: July 2022

ABSTRACT
Our understanding of stellar structure and evolution coming from one-dimensional (1D) stellar models is limited by uncertainties related to multidimensional processes taking place in stellar interiors. 1D models, however, can now be tested and improved with the help of detailed three-dimensional (3D) hydrodynamics models, which can reproduce complex multidimensional processes over short time-scales, thanks to the recent advances in computing resources. Among these processes, turbulent entrainment leading to mixing across convective boundaries is one of the least understood and most impactful. Here, we present the results from a set of hydrodynamics simulations of the neon-burning shell in a massive star, and interpret them in the framework of the turbulent entrainment law from geophysics. Our simulations differ from previous studies in their unprecedented degree of realism in reproducing the stellar environment. Importantly, the strong entrainment found in the simulations highlights the major flaws of the current implementation of convective boundary mixing in 1D stellar models. This study therefore calls for major revisions of how convective boundaries are modelled in 1D, and in particular the implementation of entrainment in these models. This will have important implications for supernova theory, nucleosynthesis, neutron stars, and black holes physics.
Fragmented atomic shell around S187 H iiregion and its interaction with molecular and ionized gas
Authors: Zemlyanukha Petr , Zinchenko Igor I , Dombek Evgeny , Pirogov Lev E , Topchieva Anastasiia , Joncas Gilles , Dewangan Lokesh K , Ojha Devendra K , Ghosh Swarna K 
Published: July 2022

ABSTRACTThe environment of S187, a nearby H ii region (1.4 ± 0.3 kpc), is analyzed. A surrounding shell has been studied in the H i line, molecular lines, and also in infrared and radio continua. We report the first evidence of a clumpy H i environment in its photodissociation region. A background radio galaxy enables the estimation of the properties of cold atomic gas. The estimated atomic mass fraction of the shell is ∼260 M⊙, the median spin temperature is ∼50 K, the shell size is ∼4 pc with typical wall width around 0.2 pc. The atomic shell consists of ∼100 fragments. The fragment sizes correlate with mass with a power-law index of 2.39–2.50. The S187 shell has a complex kinematical structure, including the expanding quasi-spherical layer, molecular envelope, an atomic sub-bubble inside the shell and two dense cores (S187 SE and S187 NE) at different stages of evolution. The atomic sub-bubble inside the shell is young, contains a Class II young stellar object and OH maser in the centre and the associated YSOs in the walls of the bubble. S187 SE and S187 NE have similar masses (∼1200 and ∼900 M⊙, respectively). S187 SE is embedded into the atomic shell and has a number of associated objects, including high-mass protostars, outflows, maser sources, and other indicators of ongoing star formation. No YSOs inside S187 NE were detected, but indications of compression and heating by the H ii region exist.
Observing the reionization: effect of calibration and position errors on realistic observation conditions
Authors: Mazumder Aishrila , Datta Abhirup , Chakraborty Arnab , Majumdar Suman 
Published: July 2022

ABSTRACT
Observation of the redshifted 21-cm signal from Cosmic Dawn and Epoch of Reionization is a challenging endeavor in observational cosmology. Presence of orders of magnitude brighter astrophysical foregrounds and various instrumental systematics increases the complexity of these observations. This work presents an end-to-end pipeline dealing with synthetic interferometric data of sensitive radio observations. The mock sky model includes the redshifted 21-cm signal and astrophysical foregrounds. The effects of calibration error and position error in the extraction of the redshifted 21-cm power spectrum has been simulated. The effect of the errors in the image plane detection of the cosmological signal has also been studied. A comparative analysis for array configurations like the SKA1-Low, MWA, and HERA has been demonstrated. The calibration error tolerance of the arrays, under some assumptions about the nature of the systematic components, is optimally found to be $\sim 0.01{{\ \rm per\ cent}}$ for the detection of the signal. For position errors, an offset of ⪆5 arcsec makes the residual foregrounds obscure the target signal. These simulations also imply that the SKA-1 Low performs marginally better than the other telescopes in the image domain. The same is true for MWA in the power spectrum domain. This is one of the first studies that compares performance of various radio telescopes operating under similar observing conditions towards detecting the cosmological signal. This end-to-end pipeline can also be extended to study effects of chromatic primary beam, radio frequency inferences, foregrounds with spectral features, etc.
The kinematics and ionization structure of the extended emission-line region of QSO E1821+643
Authors: Rosborough Sara A , Robinson A , Seelig T 
Published: July 2022

ABSTRACT
The most luminous quasars are created by major, gas-rich mergers and E1821+643, an optically luminous quasar situated at the centre of a cool-core cluster, appears to be in the late stages of the post-merger blowout phase. This quasar is also identified as a gravitational recoil candidate, in which the supermassive black hole (SMBH) has received a recoil kick due to anisotropic emission of gravitational waves during the coalescence of a progenitor SMBH binary. We analyse long-slit spectra of the extended, ionized gas surrounding E1821+643 to study its kinematics and ionization. We have identified three kinematically distinct components, which we associate, respectively, with a wide-angle polar wind from the nucleus, kinematically undisturbed gas, and a redshifted arc-like structure of gas, at a distance of 3–4 arcsec (13–18 kpc) from the nucleus. The latter component coincides with the northern and eastern extremities of an arc of [O iii] emission seen in HST images. This feature could trace a tidal tail originating from a merger with a gas-rich galaxy to the south-east of the nucleus, whose presence has been inferred by Aravena et al. from the detection of CO emission. Alternatively, the arc could be the remnant of a shell of gas swept up by a powerful quasar wind. The emission-line ratios of the extended gas are consistent with photoionization by the quasar, but a contribution from radiative shocks cannot be excluded.
Tracing a decade of activity towards a yellow hypergiant. The spectral and spatial morphology of IRC+10420 at au scales
Authors: Koumpia Evgenia , Oudmaijer R D , de Wit W-J , Mérand A , Black J H , Ababakr K M 
Published: July 2022

ABSTRACT
The fate of a massive star during the latest stages of its evolution is highly dependent on its mass-loss history and geometry, with the yellow hypergiants (YHGs) being key objects. We present near-IR interferometric observations of the famous YHG IRC+10420 and blue spectra taken between 1994 and 2019. Our 2.2-μm GRAVITY/VLTI observations attain a spatial resolution of ∼5 stellar radii and spatially resolve the hot emission in the K-band tracing the gas via Na i doublet emission and the Br γ emission. Our geometric modelling reveals a compact neutral zone (Na i) which is slightly larger than the continuum but within an extended Br γ emitting region. Our study confirms an hour-glass geometry of the wind, but we find no signature of a companion at 7–800 au separations at the contrast limit of our observations (3.7 mag at 3σ) to explain this geometry. We report an evolution of the ejecta over 7 yr, and constrain the opening angle of the hour-glass to be &lt;10°. Lastly, we present the first blue optical spectra of IRC+10420 since 1994. The multi-epoch data indicate that the spectral type, and thus temperature, of the object has essentially remained constant during the intervening years. Therefore, the observed increase in temperature of 2000 K in less than two decades prior to 1994 is now halted. This suggests that this YHG has ‘hit’ the White Wall in the HR-diagram preventing it from evolving blue-wards, and will likely undergo a major mass-loss event in the near future.
Hidden cooling flows in clusters of galaxies
Authors: Fabian A C , Ferland G J , Sanders J S , McNamara B R , Pinto C , Walker S A 
Published: July 2022

ABSTRACT
The radiative cooling time of the hot gas at the centres of cool cores in clusters of galaxies drops down to 10 Myr and below. The observed mass cooling rate of such gas is very low, suggesting that active galactic nucleus feedback is very tightly balanced or that the soft X-ray emission from cooling is somehow hidden from view. We use an intrinsic absorption model in which the cooling and coolest gas are closely interleaved to search for hidden cooling flows in the Centaurus, Perseus, and A1835 clusters of galaxies. We find hidden mass cooling rates of between 10 and $500\,{{\rm M_{\odot }}\,{\rm yr}^{-1}}$ as the cluster mass increases, with the absorbed emission emerging in the far-infrared (FIR) band. Good agreement is found between the hidden cooling rate and observed FIR luminosity in the Centaurus Cluster. The limits on the other two clusters allow for considerable hidden cooling. The implied total mass of cooled gas is much larger than the observed molecular masses. We discuss its fate including possible further cooling and collapse into undetected very cold clouds, low-mass stars, and substellar objects.
ExoMol line lists – XLVI. Empirical rovibronic spectra of silicon mononitrate (SiN) covering the six lowest electronic states and four isotopologues
Authors: Semenov Mikhail , Clark Nicholas , Yurchenko Sergei N , Kim Gap-Sue , Tennyson Jonathan 
Published: July 2022

ABSTRACT
Silicon mononitride (28Si14N, 29Si14N, 30Si14N, 28Si15N) line lists covering infrared, visible, and ultraviolet regions are presented. The SiNful line lists produced by ExoMol include rovibronic transitions between six electronic states: $X\, {}^{2}\Sigma ^{+}$, $A\, {}^{2}\Pi$, $B\, {}^{2}\Sigma ^{+}$, $D\, {}^{2}\Delta$, $a\, {}^{4}\Sigma ^{+}$, $b\, {}^{4}\Pi$. The ab initio potential energy and coupling curves, computed at the multireference configuration interaction (MRCI/aug-cc-pVQZ) level of theory, are refined for the observed states by fitting their analytical representations to 1052 experimentally derived SiN energy levels determined from rovibronic bands belonging to the X–X, A–X, and B–X electronic systems through the MARVEL procedure. The SiNful line lists are compared to previously observed spectra, recorded and calculated lifetimes, and previously calculated partition functions. SiNful is available via the www.exomol.com database.
Translation and rotation equivariant normalizing flow (TRENF) for optimal cosmological analysis
Authors: Dai Biwei , Seljak Uroš 
Published: July 2022

ABSTRACT
Our Universe is homogeneous and isotropic, and its perturbations obey translation and rotation symmetry. In this work, we develop translation and rotation equivariant normalizing flow (TRENF), a generative normalizing flow (NF) model which explicitly incorporates these symmetries, defining the data likelihood via a sequence of Fourier space-based convolutions and pixel-wise non-linear transforms. TRENF gives direct access to the high dimensional data likelihood p(x|y) as a function of the labels y, such as cosmological parameters. In contrast to traditional analyses based on summary statistics, the NF approach has no loss of information since it preserves the full dimensionality of the data. On Gaussian random fields, the TRENF likelihood agrees well with the analytical expression and saturates the Fisher information content in the labels y. On non-linear cosmological overdensity fields from N-body simulations, TRENF leads to significant improvements in constraining power over the standard power spectrum summary statistic. TRENF is also a generative model of the data, and we show that TRENF samples agree well with the N-body simulations it trained on, and that the inverse mapping of the data agrees well with a Gaussian white noise both visually and on various summary statistics: when this is perfectly achieved the resulting p(x|y) likelihood analysis becomes optimal. Finally, we develop a generalization of this model that can handle effects that break the symmetry of the data, such as the survey mask, which enables likelihood analysis on data without periodic boundaries.
Predictions for the X-ray circumgalactic medium of edge-on discs and spheroids
Authors: Nica Anna , Oppenheimer Benjamin D , Crain Robert A , Bogdán Ákos , Davies Jonathan J , Forman William R , Kraft Ralph P , ZuHone John A 
Published: July 2022

ABSTRACT
We investigate how the X-ray circumgalactic medium (CGM) of present-day galaxies depends on galaxy morphology and azimuthal angle using mock observations generated from the EAGLE cosmological hydrodynamic simulation. By creating mock stacks of eROSITA-observed galaxies oriented to be edge-on, we make several observationally testable predictions for galaxies in the stellar mass range M⋆ = 1010.7–11.2 M⊙. The soft X-ray CGM of disc galaxies is between 60 and 100 per cent brighter along the semimajor axis compared to the semiminor axis, between 10 and 30 kpc. This azimuthal dependence is a consequence of the hot (T &gt; 106 K) CGM being non-spherical: specifically, it is flattened along the minor axis such that denser and more luminous gas resides in the disc plane and corotates with the galaxy. Outflows enrich and heat the CGM preferentially perpendicular to the disc, but we do not find an observationally detectable signature along the semiminor axis. Spheroidal galaxies have hotter CGMs than disc galaxies related to spheroids residing at higher halo masses, which may be measurable through hardness ratios spanning the 0.2–1.5 keV band. While spheroids appear to have brighter CGMs than discs for the selected fixed M⋆ bin, this owes to spheroids having higher stellar and halo masses within that M⋆ bin, and obscures the fact that both simulated populations have similar total CGM luminosities at the exact same M⋆. Discs have brighter emission inside 20 kpc and more steeply declining profiles with radius than spheroids. We predict that the eROSITA 4-yr all-sky survey should detect many of the signatures we predict here, although targeted follow-up observations of highly inclined nearby discs after the survey may be necessary to observe some of our azimuthally dependant predictions.
The analysis of the iron-rich spectra of a sample of narrow-line Seyfert 1 galaxies
Authors: Paul Bynish , Winkler Hartmut , Potter Stephen 
Published: July 2022

ABSTRACT
We analyse medium resolution optical spectra of 14 narrow-line Seyfert 1 galaxies with average to strong iron emission. The targets were observed several times over a 2-yr period to probe the nature of spectral variations. Parameters determined from fitting the line profiles include relative strength, width, and asymmetry. We explore the applicability of various profile combinations to H β. We achieve satisfactory fits using three components: the narrow and broad components characteristic of all Seyfert 1 galaxies and that are reasonably represented by Gaussian profiles, and an intermediate component with width similar to that of the Fe ii lines. This intermediate component accounted for the largest fraction of the H β flux in most of our sample, especially when fitted with a Lorentzian instead of a Gaussian profile. This Lorentzian component improves the overall H β fits in most cases. In contrast to many other types of active galactic nucleus, no dramatic spectral changes were detected in our sample over the 2-yr period spanning this study, even though some of our targets are known for large and rapid X-ray variability. In particular, we find the variability of the Fe ii lines relative to the H β intermediate component to be minimal. For the [O iii] lines, we identified asymmetries in almost all our targets well represented by two Gaussians: a primary central and a second blueshifted component. These may signify different gas dynamics connected with nuclear outflow. As in several previous studies, we identify a clear correlation between [O iii] asymmetry and its core component width.
Milky Way-like galaxies: stellar population properties of dynamically defined discs, bulges and stellar haloes
Authors: Ortega-Martinez Sara , Obreja Aura , Dominguez-Tenreiro Rosa , Pedrosa Susana E , Rosas-Guevara Yetli , Tissera Patricia B 
Published: July 2022

ABSTRACT
The formation of galaxies can be understood in terms of the assembly patterns of each type of galactic component. To perform this kind of analysis, it is necessary to define some criteria to separate those components. Decomposition methods based on dynamical properties are more physically motivated than photometry-based ones. We use the unsupervised Gaussian Mixture model of galactic structure finder to extract the components of a sub-sample of galaxies with Milky Way-like masses from the eagle simulations. A clustering in the space of first- and second-order dynamical moments of all identified substructures reveals five types of galaxy components: thin and thick discs, stellar haloes, bulges and spheroids. We analyse the dynamical, morphological and stellar population (SP) properties of these five component types, exploring to what extent these properties correlate with each other, and how much they depend on the total galaxy stellar and dark matter halo masses. All galaxies contain a bulge, a stellar halo and a disc. In total, 60 per cent of objects host two discs (thin and thick), and 68 per cent host also a spheroid. The dynamical disc-to-total ratio does not depend on stellar mass, but the median rotational velocities of the two discs do. Thin discs are well separated in stellar ages, [Fe/H] and α-enhancement from the three dispersion-dominated components, while thick discs are in between. Except for thin discs, all components show correlations among their SP properties: older ages mean lower metallicities and larger α-enhancement. Finally, we quantify the weak dependence of SP properties on each component’s dynamics.