Solar and Stellar Astrophysics

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New submissions for Mon, 20 May 24

[1]  arXiv:2405.10380 [pdf, other]

Title: A kinematic origin of the white dwarfs in the Solar neighborhood

Authors: Ainhoa Zubiaur (Universitat Politecnica de Catalunya, Universitaet Heidelberg), Roberto Raddi (Universitat Politecnica de Catalunya), Santiago Torres (Universitat Politecnica de Catalunya, Institut d'Estudis Espacials de Catalunya)

Comments: Accepted for publication in A&A, 11 pages,8 figures, 7 tables

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

Thanks to the recent space-borne mission Gaia, there is a nearly complete sample of white dwarfs up to about 100 parsecs from the Sun, which may have very diverse origins. We aim to compute the Galactic orbits for white dwarfs observed in our Solar neighborhood, in order to analyze the most probable regions of the Galaxy where they could have formed, the distribution of their orbital parameters, as well as the observational biases introduced when constructing the local sample. We used a detailed Galactic orbit integration package, in conjunction with a detailed population synthesis code specifically designed to replicate the different Galactic components of the white dwarf population. Synthetic stars are generated based on the current observational sample, and subsequently, their orbital integration allows for the reconstruction of the population past history. Our kinematic analysis reveals that the majority of thin disk, thick disk, and halo white dwarfs will have left our 100 pc neighborhood in approximately 3.30, 1.05, and 0.6 Myr, respectively. The spatial distribution of the integrated thin disk orbits suggests that 68 percent of these stars were formed at less than 1 kpc from the Sun, while most of thick disk members suffered from radial disk migration. The local halo white dwarfs typically belong to the "inner halo", being their orbits mostly planar and not extending beyond R = 20-25 kpc. Despite the observational bias, the distribution of orbital parameters is well represented by the observed sample. The Solar neighborhood is a transitory concept, which must be taken into account when analyzing the overall properties of such a population, such as its age distribution, metallicities or formation history. Even so, the kinematic properties observed by recent missions such as Gaia are representative of the total population up to a distance of approximately 500 pc [abridged].

[2]  arXiv:2405.10427 [pdf, other]

Title: The accretion burst of the massive young stellar object G323.46 -0.08

Authors: V. Wolf, B. Stecklum, A. Caratti o Garatti, P. A. Boley, Ch. Fischer, T. Harries, J. Eislöffel, H. Linz, A. Ahmadi, J. Kobus, X. Haubois, A. Matter, P. Cruzalebes

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

Accretion bursts from low-mass young stellar objects (YSOs) are known for many decades. In recent years, the first accretion bursts of massive YSOs (MYSOs) were observed. These phases of intense protostellar growth are of particular importance for studying massive star formation. Bursts of MYSOs are accompanied by flares of Class II methanol masers (hereafter masers), caused by an increase in exciting mid-infrared (MIR) emission. The G323.46$-$0.08 (hereafter G323) event extends the small sample of known MYSO bursts. Maser observations of the MYSO G323 show evidence of a flare, which was presumed to be caused by an accretion burst. This should be verified with IR data. We used time-dependent radiative transfer (TDRT) to characterize the heating and cooling timescales for eruptive MYSOs and to infer the main burst parameters. The G323 accretion burst is confirmed. It reached its peak in late 2013/early 2014 with a Ks-band increase of 2.5mag. TDRT indicates that the duration of the thermal afterglow in the far-infrared (FIR) can exceed the burst duration by years. The latter was proved by SOFIA observations, which indicate a flux increase of $(14.2\pm4.6)$% at $70\, \rm \mu m$ and $(8.5\pm6.1)$% at $160\, \mu$m in 2022 (2 years after the burst end). A one-sided light echo emerged that was propagating into the interstellar medium. The G323 burst is probably the most energetic MYSO burst observed so far. Within $8.4 \rm \, yrs$, an energy of $(0.9\pm_{0.8}^{2.5}) \times 10^{47}\,\rm erg$ was released. The short timescale points to the accretion of a compact body, while the burst energy corresponds to an accumulated mass of at least $(7\pm_{6}^{20})\,M_{Jup}$ and possibly even more if the protostar is bloated. In this case, the accretion event might have triggered protostellar pulsations, which give rise to the observed maser periodicity.

[3]  arXiv:2405.10437 [pdf, other]

Title: The Alfvén Transition Zone observed by the Parker Solar Probe in Young Solar Wind -- Global Properties and Model Comparisons

Authors: Rohit Chhiber, Francesco Pecora, Arcadi V Usmanov, William H Matthaeus, Melvyn L Goldstein, Sohom Roy, Jiaming Wang, Panisara Thepthong, David Ruffolo

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Space Physics (physics.space-ph)

The transition from subAlfv\'enic to superAlfv\'enic flow in the solar atmosphere is examined by means of Parker Solar Probe (PSP) measurements during solar encounters 8 to 14. Around 220 subAlfv\'enic periods with a duration $\ge$ 10 minutes are identified. The distribution of their durations, heliocentric distances, and Alfv\'en Mach number are analyzed and compared with a global magnetohydrodynamic model of the solar corona and wind, which includes turbulence effects. The results are consistent with a patchy and fragmented morphology, and suggestive of a turbulent Alfv\'en zone within which the transition from subAlfv\'enic to superAlfv\'enic flow occurs over an extended range of helioradii. These results inform and establish context for detailed analyses of subAlfv\'enic coronal plasma that are expected to emerge from PSP's final mission phase, as well as for NASA's planned PUNCH mission.

[4]  arXiv:2405.10454 [pdf, ps, other]

Title: The long-period spectroscopic orbit and dust creation in the Wolf-Rayet binary system WR 125

Authors: Noel D. Richardson, Andrea R. Daly, Peredur M. Williams, Grant M. Hill, Victor I. Shenavrin, Izumi Endo, André-Nicolas Chené, Nicole Karnath, Ryan M. Lau, Anthony F. J. Moffat, Gerd Weigelt

Comments: accepted to ApJ

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

Several long-period binaries with a carbon-rich Wolf-Rayet star and an O star produce dust in their wind collisions. In eccentric binaries, this is seen most strongly near periastron passage. The exact conditions leading to dust creation require orbital properties to be determined, which is difficult owing to their long periods. Recently, the binary system WR 125 (WC7+O9III) began a dust creation episode seen through an infrared outburst first detected by NEOWISE-R, which was the first outburst detected since 1991. We present new near- and mid-infrared photometry, which we use to show consistency between the two outbursts and derive an orbital period of 28.12$^{+0.10}_{-0.05}$ yr. We use a long time-series of optical spectra to place the first constraints on its orbital elements, on the assumption that this system will produce dust near periastron. The orbit has a mild eccentricity of 0.29$\pm$0.12 and is only derived for the Wolf-Rayet component, as the O star's radial velocities have noise that is likely larger than the expected semi-amplitude of the orbit. We also present SOFIA/FORCAST grism spectroscopy to examine the infrared spectral energy distribution (SED) of the dust during this outburst, comparing its properties to other WCd binaries, deriving a dust temperature of 580 K in 2021. This collection of observations will allow us to plan future observations of this system and place the system in the context of dust-creating Wolf-Rayet binaries.

[5]  arXiv:2405.10472 [pdf, other]

Title: Solar Models and Astrophysical S-factors Constrained by Helioseismic Results and Updated Neutrino Fluxes

Authors: Wuming Yang, Zhijia Tian

Comments: Accepted for publication in ApJ, 29 pages, 9 figures, 5 tables

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics - Experiment (hep-ex); Nuclear Theory (nucl-th)

The ratio of metal abundance to hydrogen abundance of the solar photosphere, $(Z/X)_{s}$, has been revised several times. Standard solar models, based on these revised solar abundances, are in disagreement with seismically inferred results. Recently, Magg et al. introduced a new value for $(Z/X)_{s}$, which is still in debate in the community. The solar abundance problem or solar modeling problem remains a topic of ongoing debate. We constructed rotating solar models in accordance with various abundance scales where the effects of convection overshoot and enhanced diffusion were included. Among these models, those utilizing Magg's abundance scale exhibit superior sound-speed and density profiles compared to models using other abundance scales. Additionally, they reproduce the observed frequency separation ratios $r_{02}$ and $r_{13}$. These models also match the seismically inferred surface helium abundance and convection zone depth within $1\sigma$ level. Furthermore, the calculated neutrino fluxes from these models agree with detected ones at the level of $1\sigma$. We found that neutrino fluxes and density profile are influenced by nuclear reactions, allowing us to use the combination of detected neutrino fluxes and seismically inferred density for diagnosing astrophysical $S$-factors. This diagnostic approach shows that $S_{11}$ may be underestimated by $2\%$, while $S_{33}$ may be overestimated by about $3\%$ in previous determinations. The $S$-factors favored by updated neutrino fluxes and helioseismic results can lead to significant improvements in solar models.

[6]  arXiv:2405.10595 [pdf, other]

Title: The first low-mass eclipsing binary within the fully convective zone from TMTS

Authors: Cheng Liu, Xiaofeng Wang, Xiaobing Zhang, Mikhail Kovalev, Jie Lin, Gaobo Xi, Jun Mo, Gaici Li, Haowei Peng, Xin Li, Qiqi Xia, Abdusamatjan Iskandar, Xiangyun Zeng, Letian Wang, Liying Zhu, Xuan Song, Jincheng Guo, Xiaojun Jiang, Shengyu Yan, Jicheng Zhang

Comments: 12 pages, 8 figures, and 5 tables

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

We present a comprehensive photometric and spectroscopic analysis of the short-period ($\sim$5.32 hours) and low-mass eclipsing binary TMTSJ0803 discovered by Tsinghua-Ma Huateng Telescope for Survey (TMTS). By fitting the light curves and radial velocity data with the Wilson--Devinney code, we find that the binary is composed of two late spotted active M dwarfs below the fully convective boundary. This is supported by the discovery of a significant Balmer emission lines in the LAMOST spectrum and prominent coronal X-ray emission. In comparison with the typical luminosity of rapidly rotating fully convective stars, the much brighter X-ray luminosity ($L_{X}/L_{\rm{bol}} = 0.0159 \pm 0.0059$) suggests the stellar magnetic activity of fully convective stars could be enhanced in such a close binary system. Given the metallicity of [M/H] = $-$ 0.35 dex as inferred from the LAMOST spectrum, we measure the masses and radii of both stars to be $M_{1} = 0.169 \pm 0.010~M_{\odot}$, $M_{2} = 0.162 \pm 0.016~M_{\odot}$, $R_{1} = 0.170 \pm 0.006~R_{\odot}$, and $R_{2} = 0.156 \pm 0.006~R_{\odot}$, respectively. Based on the luminosity ratio from the light curve modeling, the effective temperatures of two components are also estimated. In comparison with the stellar evolution models, the radii and effective temperatures of two components are all below the isochrones. The radius deflation might be mainly biased by a small radial velocity (RV) data or (and) a simple correction on RVs, while the discrepancy in effective temperature might be due to the enhanced magnetic activity in this binary.

[7]  arXiv:2405.10614 [pdf, other]

Title: A study of nine extreme low mass ratio contact binary systems

Authors: E. Lalounta, P.-E. Christopoulou, A. Papageorgiou, C. E. Ferreira Lopes, M. Catelan

Comments: 16 pages, 8 figures

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

Low mass ratio systems (LMR) are a very interesting class of contact eclipsing binaries challenging the theoretical models of stability. These systems are also considered possible progenitors of the rare low-mass optical transients called red novae. In this study, we present the identification of 7 new totally eclipsing LMR systems from Catalina Sky Surveys (CSS) and 77 LMR candidates from the All Sky Automated Survey (ASAS$-$3). Using the available CSS light curves and new multiband observations for CSS$\_$J210228.3$-$031048 and CSS$\_$J231513.$+$345335 with the 2.3 m Aristarchos telescope at Helmos Observatory, we estimate their physical and absolute parameters and investigate their stability and their progenitors. The light curves are analyzed by performing a 2$-$dimension scan on the mass ratio $-$ inclination plane with Phoebe$-$0.31 scripter while the errors are estimated using Monte-Carlo simulations and heuristic scanning of the parameter space. Our analysis revealed that all 9 CSS systems have extreme mass ratios from 0.09 to 0.16. Our statistical analysis of well$-$studied LMR contact binaries shows that LMR systems tend to have warmer and more massive primaries. The investigation of the progenitors of both low and higher-mass ratio systems reveals a trend for the former to originate from higher-mass ancestors. Finally, we investigate the stability condition by calculating the ratio of spin angular momentum to orbital angular momentum and other stability indicators in the context of the reliability of the solutions.

[8]  arXiv:2405.10615 [pdf, other]

Title: Cannibals in PARADISE: The effect of merging interplanetary shocks on solar energetic particle events

Authors: Antonio Niemela, Nicolas Wijsen, Angels Aran, Luciano Rodriguez, Jasmina Magdalenic, Stefaan Poedts

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Space Physics (physics.space-ph)

Gradual solar energetic particle (SEP) events are associated with shocks driven by coronal mass ejections (CMEs). The merging of two CMEs (so-called Cannibalistic CMEs) and the interaction of their associated shocks, has been linked to some of the most powerful solar storms ever recorded. Multiple studies have focused on the observational aspects of these SEP events, yet only a handful have focused on modeling similar CME-CME interactions in the heliosphere using advanced magnetohydrodynamic (MHD) models. This work presents, to our knowledge, the first modeling results of a fully time-dependent 3D simulation that captures both the interaction of two CMEs and its effect on the acceleration and transport of SEPs. This is achieved by using an MHD model for the solar wind and CME propagation together with an integrated SEP model. We perform different simulations and compare the behavior of the energetic protons in three different solar wind environments, where a combination of two SEP-accelerating CMEs are modeled. We find that particle acceleration is significantly affected by the presence of both CMEs in the simulation. Initially, less efficient acceleration results in lower energy particles. However, as the CMEs converge and their shocks eventually merge, particle acceleration is significantly enhanced through multiple acceleration processes between CME-driven shocks, resulting in higher particle intensities and energy levels.

[9]  arXiv:2405.10680 [pdf, other]

Title: Confrontation between modelled solar integrated observables and direct observations I. Radial velocities and convective blueshift

Authors: Nadège Meunier, Anne-Marie Lagrange, Xavier Dumusque, Sophia Sulis

Comments: Paper accepted in Astronomy and Astrophysics

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)

Stellar variability strongly impacts the search for low-mass exoplanets with radial velocity techniques. Two types of planet-free time series can be used to quantify this impact: models and direct solar observations after a subtraction of the Solar System planetary contribution. Comparing these approaches is necessary for simulations. Our objective is to validate the amplitude of the convective blueshift in plages used in our previous works, particularly in blind tests, with HARPS-N solar data. We applied our model to the structures observed at the time of observations and compared the radial velocity time series. To complete our diagnosis, we studied the observed radial velocities separately for each diffraction order derived from the individual cross-correlation functions, as well as our line-by-line radial velocities. We find that our previous model had been underestimating the amplitude of the convective blueshift inhibition by a factor of about 2. A direct estimation of the convective blueshift in the spectra explains the difference with previous estimations obtained with MDI/SOHO Dopplergrams, based on the properties of the Ni line. We identified several instrumental systematics: the presence of a 2 m/s peak-to-peak signal with a period of about 200 days in radial velocity and bisector, which could be due to periodic detector warm-ups, a systematic dependence of the long-term trend on wavelength possibly related to the variability of the continuum over time, and/or an offset in radial velocity after the interruption of several months in Oct. 2017. A large amplitude in the convective blueshift inhibition of (360 m/s) must be used when building synthetic times series for blind tests. The presence of instrumental systematics should also be taken into account when using sophisticated methods based on line properties to mitigate stellar activity when searching for very weak signals.

[10]  arXiv:2405.10688 [pdf, other]

Title: From eruption to post-flare rain: a 2.5D MHD model

Authors: Samrat Sen, Avijeet Prasad, Valeriia Liakh, Rony Keppens

Comments: Accepted for publication in Astronomy and Astrophysics journal. The animation associated with Figure 3 is available on request from the corresponding author. Comments are welcome

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Plasma Physics (physics.plasm-ph)

The formation of the MFRs in the pre-flare stage, and how this leads to coronal rain in a post-eruption magnetic loop is not fully understood. We explore the formation, and eruption of MFRs, followed by the appearance of coronal rain in the post-flare loops, to understand the magnetic and thermodynamic properties of eruptive events and their multi-thermal aspects in the solar atmosphere. We perform a resistive-magnetohydrodynamic (MHD) simulation with the open-source code \texttt{MPI-AMRVAC} to explore the evolution of sheared magnetic arcades that can lead to flux rope eruptions. The system is in mechanical imbalance at the initial state, and evolves self-consistently in a non-adiabatic atmosphere under the influence of radiative losses, thermal conduction, and background heating. We use an additional level of adaptive mesh refinement to achieve the smallest cell size of $\approx 32.7$ km in each direction to reveal the fine structures in the system. The system achieves a semi-equilibrium state after a short transient evolution from its initial mechanically imbalanced condition. A series of erupting MFRs is formed due to spontaneous magnetic reconnection, across current sheets created underneath the erupting flux ropes. Gradual development of thermal imbalance is noticed at a loop top in the post-eruption phase, which leads to catastrophic cooling and formation of condensations. We obtain plasma blobs which fall down along the magnetic loop in the form of coronal rain. The dynamical and thermodynamic properties of these cool-condensations are in good agreement with observations of post-flare coronal rain. The presented simulation supports the development and eruption of multiple MFRs, and the formation of coronal rain in post-flare loops, which is one of the key aspects to reveal the coronal heating mystery in the solar atmosphere.

[11]  arXiv:2405.10699 [pdf, other]

Title: Stellar Atmospheric Parameters From Gaia BP/RP Spectra using Uncertain Neural Networks

Authors: Connor P. Fallows, Jason L. Sanders

Comments: 22 pages, 14 figures, 5 tables. Accepted by MNRAS

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)

With the plentiful information available in the Gaia BP/RP spectra, there is significant scope for applying discriminative models to extract stellar atmospheric parameters and abundances. We describe an approach to leverage an `Uncertain Neural Network' model trained on APOGEE data to provide high-quality predictions with robust estimates for per-prediction uncertainty. We report median formal uncertainties of 0.068 dex, 69.1K, 0.14 dex, 0.031 dex, 0.040 dex, and 0.029 dex for [Fe/H], $T_\mathrm{eff}$, $\log g$, [C/Fe], [N/Fe], and [$\alpha$/M] respectively. We validate these predictions against our APOGEE training data, LAMOST, and Gaia GSP-Phot stellar parameters, and see a strong correlation between our predicted parameters and those derived from these surveys. We investigate the information content of the spectra by considering the `attention' our model pays to different spectral features compared to expectations from synthetic spectra calculations. Our model's predictions are applied to the Gaia dataset, and we produce a publicly available catalogue of our model's predictions.

[12]  arXiv:2405.10790 [pdf, other]

Title: Spectroscopic evidence of cool plasma in quiet Sun HRIEUV small scale brightenings

Authors: A. Dolliou, S. Parenti, K. Bocchialini

Comments: 21 pages, 22 figures, accepted in A&A

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

Context: A large number of the small and the short-lived EUV brightenings have been detected in the quiet Sun (QS) over the past three years, by the High Resolution Imager of the Extreme Ultraviolet Imager (HRIEUV) on board Solar Orbiter. It is still uncertain whether these events reach coronal temperatures, and thus if they directly participate to coronal heating.
Aims: In this work, we evaluate the maximum temperature of 11 EUV brightenings in the QS, through plasma diagnostics involving UV/EUV spectroscopy and imaging.
Methods: We use three QS observations coordinated between HRIEUV, the Spectral Imaging of the Coronal Environment (SPICE/Solar Orbiter), the EUV Imaging Spectrometer (EIS/Hinode), and the Atmospheric Imaging Assembly (AIA/SDO). We detected events in HRIEUV, ranging from 0.8 to 6.2 Mm in length. We then identified nine of them in SPICE and AIA, as well as three in EIS. We investigated their temporal evolution using their light curves, and applied temperature diagnostics, such as the LOCI Emission Measure (EM) and the differential EM (DEM). We also estimated the electron density of one event identified in EIS.
Results: These events are dominated by emission of plasma at chromospheric and TR temperatures, and they barely reach temperatures above 1 MK. As such, we concluded that their contribution to coronal heating is not dominant. The estimated density of one of the event is n$_e$ = (1.8 $\pm$ 1.3) $\times$ $10^{10}$ cm$^{-3}$.

Cross-lists for Mon, 20 May 24

[13]  arXiv:2405.10359 (cross-list from gr-qc) [pdf, other]

Title: Non-comoving description of adiabatic radial perturbations of relativistic stars

Authors: Paulo Luz, Sante Carloni

Comments: 22 pages, 5 figures

Subjects: General Relativity and Quantum Cosmology (gr-qc); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics - Theory (hep-th)

We study adiabatic, radial perturbations of static, self-gravitating perfect fluids within the theory of general relativity employing a new perturbative formalism. We show that by considering a radially static observer, the description of the perturbations can be greatly simplified with respect to the standard comoving treatment. The new perturbation equations can be solved to derive analytic solutions to the problem for a general class of equilibrium solutions. We discuss the thermodynamic description of the fluid under isotropic frame transformations, showing how, in the radially static, non-inertial frame, the stress-energy tensor of the fluid must contain momentum transfer terms. As illustrative examples of the new approach, we study perturbations of equilibrium spacetimes characterized by the Buchdahl I, Heintzmann IIa, Patwardhan-Vaidya IIa, and Tolman VII solutions, computing the first oscillation eigenfrequencies and the associated eigenfunctions. We also analyze the properties of the perturbations of cold neutron stars composed of a perfect fluid verifying the Bethe-Johnson model I equation of state, computing the oscillation eigenfrequencies and the $e$-folding time.

[14]  arXiv:2405.10361 (cross-list from astro-ph.EP) [pdf, other]

Title: Chemistry across dust and gas gaps in protoplanetary disks: modelling the co-spatial molecular rings in the HD 100546 disk

Authors: M. Leemker, A. S. Booth, E. F. van Dishoeck, L. Wölfer, B. Dent

Comments: Accepted for publication in A&A

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)

High-resolution observations show that typically both the dust and the gas in nearby extended protoplanetary disks are structured, possibly related to radial and azimuthal variations in the disk density and/or chemistry. The aim of this work is to identify the expected location and intensity of rings seen in molecular line emission of HCN, CN, C$_2$H, NO, [CI], and HCO$^+$ in gapped disks while exploring a range of physical conditions across the gap. In particular, we model HD 100546 disk where molecular rings are co-spatial with the dust rings at $\sim$20 and $\sim$200 au, in contrast to most other gapped disks. The fiducial model of a gapped disk with a 15 au gas cavity, a 20 au dust cavity, and a shallow (a factor of $\lesssim10$) gas and deep dust gap at 40-175 au provides a good fit to the continuum, CO isotopologues, HCN, and HCO$^+$ in the HD 100546 disk. However, the predictions for [CI], CN, C$_2$H and NO do not match the intensity nor the morphology of the observations. An exploration of the parameter space shows that in general the molecular emission rings are only co-spatial with the dust rings if the gas gap between the dust rings is depleted by at least four orders of magnitude in gas or if the C/O ratio of the gas is varying as a function of radius. For shallower gaps the decrease in the UV field roughly balances the effect of a higher gas density for UV tracers such as CN, C$_2$H, and NO. Therefore, these radicals are not good tracers of the gas gap depth. The C/O ratio primarily effects the intensity of the lines without changing the morphology much. The co-spatial rings observed in the HD 100546 disk could be indicative of a radially varying C/O ratio in the HD 100546 disk with a C/O above 1 in a narrow region across the dust rings, together with a shallow gas gap that is depleted by a factor of $\sim$10 in gas, and a reduced background UV field.

[15]  arXiv:2405.10379 (cross-list from astro-ph.EP) [pdf, other]

Title: Wide Binary Orbits are Preferentially Aligned with the Orbits of Small Planets, but Probably Not Hot Jupiters

Authors: Sam Christian, Andrew Vanderburg, Juliette Becker, Adam L. Kraus, Logan Pearce, Karen A. Collins, Malena Rice, Eric L. N. Jensen, David Baker, Paul Benni, Allyson Bieryla, Abraham Binnenfeld, Kevin I. Collins, Dennis M. Conti, Phil Evans, Eric Girardin, Joao Gregorio, Tsevi Mazeh, Felipe Murgas, Aviad Panahi, Francisco J. Pozuelos, Howard M. Relles, Fabian Rodriguez Frustaglia, Richard P. Schwarz, Gregor Srdoc, Chris Stockdale, Thiam-Guan Tan, William C. Waalkes, Gavin Wang, Justin Wittrock, Shay Zucker

Comments: 16 pages, 10 figures, submitted to AJ. Email corresponding author for data files

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

Studying the relative orientations of the orbits of exoplanets and wide-orbiting binary companions (semimajor axis greater than 100 AU) can shed light on how planets form and evolve in binary systems. Previous observations by multiple groups discovered a possible alignment between the orbits of visual binaries and the exoplanets that reside in them. In this study, using data from \textit{Gaia} DR3 and TESS, we confirm the existence of an alignment between the orbits of small planets $(R<6 R_\oplus)$ and binary systems with semimajor axes below 700 AU ($p=10^{-6}$). However, we find no statistical evidence for alignment between planet and binary orbits for binary semimajor axes greater than 700 AU, and no evidence for alignment of large, closely-orbiting planets (mostly hot Jupiters) and binaries at any separation. The lack of orbital alignment between our large planet sample and their binary companions appears significantly different from our small planet sample, even taking into account selection effects. Therefore, we conclude that any alignment between wide-binaries and our sample of large planets (predominantly hot Jupiters) is probably not as strong as what we observe for small planets in binaries with semimajor axes less than 700 AU. The difference in the alignment distribution of hot Jupiters and smaller planets may be attributed to the unique evolutionary mechanisms occuring in systems that form hot Jupiters, including potentially destabilizing secular resonances that onset as the protoplanetary disk dissipates and high-eccentricity migration occurring after the disk is gone.

[16]  arXiv:2405.10810 (cross-list from physics.space-ph) [pdf, other]

Title: Flux rope modeling of the 2022 Sep 5 CME observed by Parker Solar Probe and Solar Orbiter from 0.07 to 0.69 au

Authors: Emma E. Davies (1), Hannah T. Rüdisser (1), Ute V. Amerstorfer (1), Christian Möstl (1), Maike Bauer (1), Eva Weiler (1), Tanja Amerstorfer (1), Satabdwa Majumdar (1), Phillip Hess (2), Andreas J. Weiss (3), Martin A. Reiss (4), Lucie M. Green (5), David M. Long (6), Teresa Nieves-Chinchilla (7,8), Domenico Trotta (9), Timothy S. Horbury (9), Helen O'Brien (9), Edward Fauchon-Jones (9), Jean Morris (9), Christopher J. Owen (5), Stuart D. Bale (10), Justin C. Kasper (11) ((1) Austrian Space Weather Office, GeoSphere Austria, Graz, Austria, (2) U.S. Naval Research Laboratory, Washington, DC, USA, (3) NASA Postdoctoral Program Fellow, NASA Goddard Space Flight Center, Greenbelt, MD, USA, (4) Community Coordinated Modeling Center, NASA Goddard Space Flight Center, Greenbelt, MD, USA, (5) University College London, Mullard Space Science Laboratory, UK, (6) School of Physical Sciences, Dublin City University, Dublin, Ireland, (7) Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD, USA, (8) Department of Physics and Astronomy, George Mason University, Fairfax, VA, USA, (9) Imperial College London, South Kensington Campus, London, UK, (10) Physics Department and Space Sciences Laboratory, University of California, Berkeley, USA, (11) School of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, Michigan, USA)

Subjects: Space Physics (physics.space-ph); Solar and Stellar Astrophysics (astro-ph.SR)

As both Parker Solar Probe (PSP) and Solar Orbiter (SolO) reach heliocentric distances closer to the Sun, they present an exciting opportunity to study the structure of CMEs in the inner heliosphere. We present an analysis of the global flux rope structure of the 2022 September 5 CME event that impacted PSP at a heliocentric distance of only 0.07 au and SolO at 0.69 au. We compare in situ measurements at PSP and SolO to determine global and local expansion measures, finding a good agreement between magnetic field relationships with heliocentric distance, but significant differences with respect to flux rope size. We use PSP/WISPR images as input to the ELEvoHI model, providing a direct link between remote and in situ observations; we find a large discrepancy between the resulting modeled arrival times, suggesting that the underlying model assumptions may not be suitable when using data obtained close to the Sun, where the drag regime is markedly different in comparison to larger heliocentric distances. Finally, we fit the SolO/MAG and PSP/FIELDS data independently with the 3DCORE model and find that many parameters are consistent between spacecraft, however, challenges are apparent when reconstructing a global 3D structure that aligns with arrival times at PSP and Solar Orbiter, likely due to the large radial and longitudinal separations between spacecraft. From our model results, it is clear the solar wind background speed and drag regime strongly affects the modeled expansion and propagation of CMEs and needs to be taken into consideration.

[17]  arXiv:2405.10841 (cross-list from astro-ph.EP) [pdf, other]

Title: The ESO SupJup Survey I: Chemical and isotopic characterisation of the late L-dwarf DENIS J0255-4700 with CRIRES$^+$

Authors: S. de Regt, S. Gandhi, I. A. G. Snellen, Y. Zhang, C. Ginski, D. González Picos, A. Y. Kesseli, R. Landman, P. Mollière, E. Nasedkin, A. Sánchez-López, T. Stolker

Comments: Submitted to A&A

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

It has been proposed that the distinct formation and evolution of exoplanets and brown dwarfs may affect the chemical and isotopic content of their atmospheres. Recent work has indeed shown differences in the $^{12}$C/$^{13}$C isotope ratio, provisionally attributed to the top-down formation of brown dwarfs and the core accretion pathway of super-Jupiters. The ESO SupJup Survey aims to disentangle the formation pathways of isolated brown dwarfs and planetary-mass companions using chemical and isotopic tracers. The survey uses high-resolution spectroscopy with the recently upgraded VLT/CRIRES$^+$ spectrograph, covering a total of 49 targets. Here, we present the first results: an atmospheric characterisation of DENIS J0255-4700, an isolated brown dwarf near the L-T transition. We analyse its K-band spectrum using a retrieval framework where the radiative transfer code petitRADTRANS is coupled to PyMultiNest. Gaussian Processes are employed to model inter-pixel correlations and we adopt an updated parameterisation of the PT-profile. Abundances of CO, H$_2$O, CH$_4$, and NH$_3$ are retrieved for this fast-rotating L-dwarf. The ExoMol H$_2$O line list provides a significantly better fit than that of HITEMP. A free-chemistry retrieval is strongly favoured over equilibrium chemistry, caused by an under-abundance of CH$_4$. The free-chemistry retrieval constrains a super-solar C/O-ratio of $\sim0.68$ and a solar metallicity. We find tentative evidence ($\sim3\sigma$) for the presence of $^{13}$CO, with a constraint on the isotope ratio of $\mathrm{^{12}C/^{13}C}=184^{+61}_{-40}$ and a lower limit of $\gtrsim97$, suggesting a depletion of $^{13}$C compared to the interstellar medium ($\sim68$). High-resolution, high signal-to-noise K-band spectra provide an excellent means to constrain the chemistry and isotopic content of sub-stellar objects, as is the main objective of the ESO SupJup Survey.

Replacements for Mon, 20 May 24

[18]  arXiv:2402.10611 (replaced) [pdf, other]

Title: Spectral variations within solar flare ribbons

Authors: A.G.M. Pietrow, M.K. Druett, V. Singh

Comments: Published in A&A. 11 pages, 8 figures

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

[19]  arXiv:2405.06601 (replaced) [pdf, other]

Title: A numerical code for the analysis of magnetic white dwarf spectra that includes field effects on the chemical equilibrium

Authors: Matías Vera-Rueda, René D. Rohrmann

Comments: 14 pages, 11 figures. Accepted for publication in Astronomy & Astrophysics

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

[20]  arXiv:2310.16104 (replaced) [pdf, ps, other]

Title: Planetary Engulfment Prognosis within the $ρ$ CrB System

Authors: Stephen R. Kane

Comments: 10 pages, 3 figures, 1 table, accepted for publication in the Astrophysical Journal

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

[21]  arXiv:2402.07998 (replaced) [pdf, other]

Title: On the linear stability of nonrelativistic selfinteracting boson stars

Authors: Emmanuel Chávez Nambo, Alberto Diez-Tejedor, Armando A. Roque, Olivier Sarbach

Comments: 15+1 pages and 10 figures. Minor changes were made. It was accepted in journal Physical Review D

Subjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR); Mathematical Physics (math-ph)

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