bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessing spectra and thermal inversions due to TiO in hot Jupiter atmospheres
Authors: Piette Anjali A A , Madhusudhan Nikku , McKemmish Laura K , Gandhi Siddharth , Masseron Thomas , Welbanks Luis 
Published: July 2020

ABSTRACT
Recent detections of thermal inversions in the dayside atmospheres of some hot Jupiters are motivating new avenues to understand the interplay between their temperature structures and other atmospheric conditions. In particular, TiO has long been proposed to cause thermal inversions in hot Jupiters, depending on other factors such as stellar irradiation, C/O, and vertical mixing. TiO also has spectral features in the optical and near-infrared that have been detected. However, interpretations of TiO signatures rely on the accuracy of TiO opacity used in the models. The recently reported toto TiO line list provides a new opportunity to investigate these dependences, which is the goal of this work. First, we investigate how the toto line list affects observable transmission and emission spectra of hot Jupiters at low and high resolutions. The improvement in the toto line list compared to a previous line list results in observable differences in the model spectra, particularly in the optical at high resolution. Secondly, we explore the interplay between temperature structure, irradiation, and composition with TiO as the primary source of optical opacity, using 1D self-consistent atmospheric models. Among other trends, we find that the propensity for thermal inversions due to TiO peaks at C/O ∼ 0.9, consistent with recent studies. Using these models, we further assess metrics to quantify thermal inversions due to TiO, compared to frequently used Spitzer photometry, over a range in C/O, irradiation, metallicity, gravity, and stellar type.
CoMaLit – VI. Intrinsic scatter in stacked relations. The weak lensing AMICO galaxy clusters in KiDS-DR3
Authors: Sereno Mauro , Ettori Stefano , Lesci Giorgio F , Marulli Federico , Maturi Matteo , Moscardini Lauro , Radovich Mario , Bellagamba Fabio , Roncarelli Mauro 
Published: July 2020

ABSTRACT
Unbiased and precise mass calibration of galaxy clusters is crucial to fully exploit galaxy clusters as cosmological probes. Stacking of weak lensing (WL) signal allows us to measure observable–mass relations down to less massive haloes without extrapolation. We propose a Bayesian inference method to constrain the intrinsic scatter of the mass proxy in stacked analyses. The scatter of the stacked data is rescaled with respect to the individual scatter based on the number of binned clusters. We apply this method to the galaxy clusters detected with the AMICO (Adaptive Matched Identifier of Clustered Objects) algorithm in the third data release of the Kilo-Degree Survey. The results confirm the optical richness as a low-scatter mass proxy. Based on the optical richness and the calibrated WL mass–richness relation, mass of individual objects down to $\sim\! 10^{13}\, \mathrm{M}_\odot$ can be estimated with a precision of ∼20 per cent.
Oxygen loss from simulated galaxies and the metal flow main sequence: predicting the dependence on mass and environment
Authors: Taylor Philip , Kobayashi Chiaki , Kewley Lisa J 
Published: July 2020

ABSTRACT
We predict the mass fraction of oxygen lost from galaxies in a cosmological simulation as a function of stellar mass and environment at the present day. The distribution with stellar mass is bimodal, separating star-forming and quenched galaxies. The metallicity of gas and stars is self-consistently calculated using a chemical evolution model that includes Type II and Ia supernovae, hypernovae, and asymptotic giant branch stars. The mass of oxygen lost from each galaxy is calculated by comparing the existing oxygen in gas and stars in the galaxy to the oxygen that should have been produced by the present-day population of stars. More massive galaxies are able to retain a greater fraction of their metals (∼100 per cent) than low-mass galaxies (∼40–70 per cent). As in the star formation main sequence, star-forming galaxies follow a tight relationship also in terms of oxygen mass lost – a metal flow main sequence – whereas massive quenched galaxies tend to have lost a greater fraction of oxygen (up to 20 per cent), due to active galactic nucleus-driven winds. The amount of oxygen lost by satellite galaxies depends on the details of their interaction history, and those in richer groups tend to have lost a greater fraction of their oxygen. Observational estimates of metal retention in galaxies will provide a strong constraint on models of galaxy evolution.
An application of a solar-type dynamo model for ε Eridani
Authors: Buccino A P , Sraibman L , Olivar P M , Minotti F O 
Published: July 2020

ABSTRACT
During the last decade, the relation between activity cycle periods and stellar parameters has received special attention. The construction of reliable registries of activity reveals that solar-type stars exhibit activity cycles with periods from few years to decades and, in some cases, long and short activity cycles coexist suggesting that two dynamos could operate in these stars. In particular, ε Eridani is an active young K2V star (0.8 Gyr), which exhibits short and long-term chromospheric cycles of ∼3 and ∼13-yr periods. Additionally, between 1985 and 1992, the star went through a broad activity minimum, similar to the solar Maunder Minimum state.
Motivated by these results, we found in ε Eridani a great opportunity to test the dynamo theory. Based on the model developed in Sraibman & Minotti, in this work we built a non-linear axisymmetric dynamo for ε Eridani. The time series of the simulated magnetic field components near the surface integrated in all the stellar disc exhibits both the long and short activity cycles with periods similar to the ones detected from observations and also time intervals of low activity that could be associated with the broad Minimum. The short activity cycle associated with the magnetic reversal could be explained by the differential rotation, while the long cycle is associated with the meridional mass flows induced by the Lorentz force. In this way, we show that a single non-linear dynamo model derived from first principles with accurate stellar parameters could reproduce coexisting activity cycles.
NIR counterparts to ULXs (III): completing the photometric survey and selected spectroscopic results★
Authors: López K M , Heida M , Jonker P G , Torres M A P , Roberts T P , Walton D J , Moon D-S , Harrison F A 
Published: July 2020

ABSTRACT
We present results from the remaining sources in our search for near-infrared (NIR) candidate counterparts to ultraluminous X-ray sources (ULXs) within ≃10 Mpc. We observed 23 ULXs in 15 galaxies and detected NIR candidate counterparts to 6 of them. Two of these have an absolute magnitude consistent with a single red supergiant (RSG). Three counterparts are too bright for an RSG and spatially extended, and thus we classify them as stellar clusters. The other candidate is too faint for an RSG. Additionally, we present the results of our NIR spectroscopic follow-up of five sources: four originally classified as RSG and one as a stellar cluster on the basis of previous photometry. The stellar cluster candidate is actually a nebula. Of the four RSG candidates, one source has a broad H α emission line redshifted by ∼z = 1, making it a background active galactic nucleus (AGN). Two other sources show stellar spectra consistent with them being RSGs. The final RSG candidate is too faint to classify, but does not show strong (nebular) emission lines in its spectrum. After our search for NIR counterparts to 113 ULXs, where we detected a candidate counterpart for 38 ULXs, we have spectroscopically confirmed the nature of 12: 5 sources are nebulae, 1 source is not classified, 1 source is an AGN, and 5 are RSGs. These possible five ULX–RSG binary systems would constitute ${\simeq} (4 \pm 2){{\ \rm per\ cent}}$ of the observed ULXs, a fraction almost four times larger than what was predicted by binary evolution simulations.
UV dust attenuation as a function of stellar mass and its evolution with redshift
Authors: Bogdanoska Jana , Burgarella Denis 
Published: July 2020

ABSTRACT
Studying the ultraviolet dust attenuation, as well as its relation to other galaxy parameters such as the stellar mass, plays an important role in multiwavelength research. This work relates the dust attenuation to the stellar mass of star-forming galaxies, and its evolution with redshift. A sample of galaxies with an estimate of the dust attenuation computed from the infrared excess was used. The dust attenuation versus stellar mass data, separated in redshift bins, was modelled by a single parameter linear function, assuming a non-zero constant apparent dust attenuation for low-mass galaxies. But the origin of this effect is still to be determined and several possibilities are explored (actual high dust content, variation of the dust-to-metal ratio, variation of the stars–dust geometry). The best-fitting parameter of this model is then used to study the redshift evolution of the cosmic dust attenuation and is found to be in agreement with results from the literature. This work also gives evidence to a redshift evolution of the dust attenuation–stellar mass relationship, as is suggested by recent works in the highest redshift range.
A systematic study of CO2 planetary atmospheres and their link to the stellar environment
Authors: Petralia A , Alei E , Aresu G , Locci D , Cecchi-Pestellini C , Micela G , Claudi R , Ciaravella A 
Published: July 2020

ABSTRACT
The Milky Way Galaxy is literally teeming with exoplanets; thousands of planets have been discovered, with thousands more planet candidates identified. Terrestrial-like planets are quite common around other stars, and are expected to be detected in large numbers in the future. Such planets are the primary targets in the search for potentially habitable conditions outside the Solar system. Determining the atmospheric composition of exoplanets is mandatory to understand their origin and evolution, as atmospheric processes play crucial roles in many aspects of planetary architecture. In this work we construct and exploit a 1D radiative transfer model based on the discrete-ordinates method in plane-parallel geometry. Radiative results are linked to a convective flux that redistributes energy at any altitude producing atmospheric profiles in radiative–convective equilibrium. The model has been applied to a large number (6250) of closely dry synthetic CO2 atmospheres, and the resulting pressure and thermal profiles have been interpreted in terms of parameter variability. Although less accurate than 3D general circulation models, not properly accounting for e.g. clouds and atmospheric and ocean dynamics, 1D descriptions are computationally inexpensive and retain significant value by allowing multidimensional parameter sweeps with relative ease.
Multitracer extension of the halo model: probing quenching and conformity in eBOSS
Authors: Alam Shadab , Peacock John A , Kraljic Katarina , Ross Ashley J , Comparat Johan 
Published: July 2020

ABSTRACT
We develop a new Multitracer Halo Occupation Distribution (MTHOD) framework for the galaxy distribution and apply it to the extended Baryon Oscillation Spectroscopic Survey (eBOSS) final data between z = 0.7 − 1.1. We obtain a best fitting MTHOD  for each tracer and describe the host halo properties of these galaxies. The mean halo masses for LRGs, ELGs, and QSOs are found to be $1.9 \times 10^{13} \, h^{-1}M_\odot$, $1.1 \times 10^{12} \, h^{-1}M_\odot$, and $5 \times 10^{12} \, h^{-1}M_\odot$ respectively in the eBOSS data. We use the MTHOD  framework to create mock galaxy catalogues and predict auto- and cross-correlation functions for all the tracers. Comparing these results with data, we investigate galactic conformity, the phenomenon whereby the properties of neighbouring galaxies are mutually correlated in a manner that is not captured by the basic halo model. We detect 1-halo conformity at more than 3σ statistical significance, while obtaining upper limits on 2-halo conformity. We also look at the environmental dependence of the galaxy quenching efficiency and find that halo mass driven quenching successfully explains the behaviour in high density regions, but it fails to describe the quenching efficiency in low density regions. In particular, we show that the quenching efficiency in low density filaments is higher in the observed data, as compared to the prediction of the MTHOD with halo mass driven quenching. The mock galaxy catalogue constructed in this paper is publicly available on this website1.
Filament intersections and cold dense cores in Orion A North
Authors: Zhang Chao , Ren Zhiyuan , Wu Jingwen , Li Di , Zhu Lei , Zhang Qizhou , Mardones Diego , Wang Chen , Shi Hui , Yue Nannan , Luo Gan , Xie Jinjin , Jiao Sihan , Liu Shu , Xu Xuefang , Wang Shen 
Published: July 2020

ABSTRACT
We studied the filament structures and cold dense cores in OMC-2,3 region in Orion A North molecular cloud using the high-resolution N2H+ (1-0) spectral cube observed with the Atacama Large Millimeter/Submillimeter Array (ALMA). The filament network over a total length of 2 pc is found to contain 170 intersections and 128 candidate dense cores. The dense cores are all displaced from the infrared point sources (possible young stars), and the major fraction of cores (103) are located around the intersections. Towards the intersections, there is also an increasing trend for the total column density Ntot as well as the power-law index of the column-density Probability Distribution Function (N-PDF), suggesting that the intersections would in general have more significant gas assembly than the other part of the filament paths. The virial analysis shows that the dense cores mostly have virial mass ratio of αvir = Mvir/Mgas &lt; 1.0, suggesting them to be bounded by the self-gravity. In the mean time, only about 23 per cent of the cores have critical mass ratio of αcrit = Mcrit/Mgas &lt; 1.0, suggesting them to be unstable against core collapse. Combining these results, it shows that the major fraction of the cold starless and possible pre-stellar cores in OMC-2,3 are being assembled around the intersections, and currently in a gravitationally bound state. But more extensive core-collapse and star formation may still require continuous core mass growth or other perturbations.
Analysis of the He i chromosphere in relation to the magnetic field activity over solar cycle time periods
Authors: Li K J , Feng W 
Published: July 2020

ABSTRACT
Solar synoptic maps of both He i 10 830 Å intensity and the magnetic field, which are observed by the Vacuum Telescope at National Solar Observatory/Kitt Peak from 2005 July to 2013 March are utilized to study relationship of He i intensity of the weakly magnetized chromosphere with the respective magnetic field strength. Strong absorption in He i intensity presents the butterfly-pattern latitude migration zone as active regions do, indicating that strong magnetic field corresponds to high-temperature structures of the active chromosphere. For He i intensity and magnetic field strength, their distribution at the time-latitude coordinate and their time series at each of the 180 measurement latitude are found to be significantly negatively correlated with each other in most cases. When a solar hemisphere is divided into three latitude bands: low, middle, and high latitude bands, and even after large magnetic field values not taken into account, they are still negatively correlated in most cases, and further when large magnetic field values are subtracted He i intensity varies more sensitively with magnetic field strength than the corresponding cases when large magnetic field values are not subtracted. He i intensity in the quiet chromosphere thus mainly presents a negative correlation with the magnetic field, and the heating of the quiet chromosphere is inferred to be caused mainly by small-scale magnetic elements.
Inverse-Compton scattering in the resolved jet of the high-redshift quasar PKS J1421−0643
Authors: Worrall D M , Birkinshaw M , Marshall H L , Schwartz D A , Siemiginowska A , Wardle J F C 
Published: July 2020

ABSTRACT
Despite the fact that kpc-scale inverse-Compton (iC) scattering of cosmic microwave background (CMB) photons into the X-ray band is mandated, proof of detection in resolved quasar jets is often insecure. High redshift provides favourable conditions due to the increased energy density of the CMB, and it allows constraints to be placed on the radio synchrotron-emitting electron component at high energies that are otherwise inaccessible. We present new X-ray, optical, and radio results from Chandra, HST, and the VLA for the core and resolved jet in the z = 3.69 quasar PKS J1421−0643. The X-ray jet extends for about 4.5 arcsec (32 kpc projected length). The jet’s radio spectrum is abnormally steep and consistent with electrons being accelerated to a maximum Lorentz factor of about 5000. Results argue in favour of the detection of iC X-rays for modest magnetic field strength of a few nT, Doppler factor of about 4, and viewing angle of about 15°, and predict the jet to be largely invisible in most other spectral bands including the far- and mid-infrared and high-energy gamma-ray. The jet power is estimated to be about 3 × 1046 erg s−1 which is of order a tenth of the quasar bolometric power, for an electron–positron jet. The jet radiative power is only about 0.07 per cent of the jet power, with a smaller radiated power ratio if the jet contains heavy particles, so most of the jet power is available for heating the intergalactic medium.
Towards a multitracer timeline of star formation in the LMC – I. Deriving the lifetimes of H i clouds
Authors: Ward Jacob L , Chevance Mélanie , Kruijssen J M Diederik , Hygate Alexander P S , Schruba Andreas , Longmore Steven N 
Published: July 2020

ABSTRACT
The time-scales associated with the various stages of the star formation process remain poorly constrained. This includes the earliest phases of star formation, during which molecular clouds condense out of the atomic interstellar medium. We present the first in a series of papers with the ultimate goal of compiling the first multitracer timeline of star formation, through a comprehensive set of evolutionary phases from atomic gas clouds to unembedded young stellar populations. In this paper, we present an empirical determination of the lifetime of atomic clouds using the Uncertainty Principle for Star Formation formalism, based on the de-correlation of H α and H i emission as a function of spatial scale. We find an atomic gas cloud lifetime of 48$^{+13}_{-8}$ Myr. This time-scale is consistent with the predicted average atomic cloud lifetime in the LMC (based on galactic dynamics) that is dominated by the gravitational collapse of the mid-plane ISM. We also determine the overlap time-scale for which both H i and H α emissions are present to be very short (tover &lt; 1.7 Myr), consistent with zero, indicating that there is a near-to-complete phase change of the gas to a molecular form in an intermediary stage between H i clouds and H ii regions. We utilize the time-scales derived in this work to place empirically determined limits on the time-scale of molecular cloud formation. By performing the same analysis with and without the 30 Doradus region included, we find that the most extreme star-forming environment in the LMC has little effect on the measured average atomic gas cloud lifetime. By measuring the lifetime of the atomic gas clouds, we place strong constraints on the physics that drives the formation of molecular clouds and establish a solid foundation for the development of a multitracer timeline of star formation in the LMC.
Modelling the Milky Way – I. Method and first results fitting the thick disc and halo with DES-Y3 data
Authors: Pieres A , Girardi L , Balbinot E , Santiago B , da Costa L N , Carnero Rosell A , Pace A B , Bechtol K , Groenewegen M A T , Drlica-Wagner A , Li T S , Maia M A G , Ogando R L C , dal Ponte M , Diehl H T , Amara A , Avila S , Bertin E , Brooks D , Burke D L , Carrasco Kind M , Carretero J , De Vicente J , Desai S , Eifler T F , Flaugher B , Fosalba P , Frieman J , García-Bellido J , Gaztanaga E , Gerdes D W , Gruen D , Gruendl R A , Gschwend J , Gutierrez G , Hollowood D L , Honscheid K , James D J , Kuehn K , Kuropatkin N , Marshall J L , Miquel R , Plazas A A , Sanchez E , Serrano S , Sevilla-Noarbe I , Sheldon E , Smith M , Soares-Santos M , Sobreira F , Suchyta E , Swanson M E C , Tarle G , Thomas D , Vikram V , Walker A R 
Published: July 2020

ABSTRACT
We present a technique to fit the stellar components of the Galaxy by comparing Hess Diagrams (HDs) generated from trilegal models to real data. We apply this technique, which we call mwfitting, to photometric data from the first 3 yr of the Dark Energy Survey (DES). After removing regions containing known resolved stellar systems such as globular clusters, dwarf galaxies, nearby galaxies, the Large Magellanic Cloud, and the Sagittarius Stream, our main sample spans a total area of ∼2300 deg2. We further explore a smaller subset (∼1300 deg2) that excludes all regions with known stellar streams and stellar overdensities. Validation tests on synthetic data possessing similar properties to the DES data show that the method is able to recover input parameters with a precision better than 3 per cent. We fit the DES data with an exponential thick disc model and an oblate double power-law halo model. We find that the best-fitting thick disc model has radial and vertical scale heights of 2.67 ± 0.09 kpc and 925 ± 40 pc, respectively. The stellar halo is fit with a broken power-law density profile with an oblateness of 0.75 ± 0.01, an inner index of 1.82 ± 0.08, an outer index of 4.14 ± 0.05, and a break at 18.52 ± 0.27 kpc from the Galactic centre. Several previously discovered stellar overdensities are recovered in the residual stellar density map, showing the reliability of mwfitting in determining the Galactic components. Simulations made with the best-fitting parameters are a promising way to predict Milky Way star counts for surveys such as the LSST and Euclid.
Disc formation and jet inclination effects in common envelopes
Authors: López-Cámara Diego , Moreno Méndez Enrique , De Colle Fabio 
Published: July 2020

ABSTRACT
The evolution and physics of the common envelope (CE) phase are still not well understood. Jets launched from a compact object during this stage may define the evolutionary outcome of the binary system. We focus on the case in which jets are launched from a neutron star (NS) engulfed in the outer layers of a red giant (RG). We run a set of three-dimensional hydrodynamical simulations of jets with different luminosities and inclinations. The luminosity of the jet is self-regulated by the mass accretion rate and an efficiency η. Depending on the value of η the jet can break out of the previously formed bulge (‘successful jet’) and aligns against the incoming wind, in turn, it will realign in favour of the direction of the wind. The jet varies in size and orientation and may present quiescent and active epochs. The inclination of the jet and the Coriolis and centrifugal forces, only slightly affect the global evolution. As the accretion is hypercritical, and the specific angular momentum is above the critical value for the formation of a disc, we infer the formation of a disc and launching of jets. The discs’ mass and size would be ∼10−2 M⊙ and ≳1010 cm, and it may have rings with different rotation directions. In order to have a successful jet from a white dwarf, the ejection process needs to be very efficient (η ∼ 0.5). For main-sequence stars, there is not enough energy reservoir to launch a successful jet.