ASTRONOMY & ASTROPHYSICS 是一本国际期刊，独立于用于获得结果的技术发表关于天文学和天体物理学（理论、观测和仪器）各个方面的论文。

Astronomy and Astrophysics is an international journal that focuses on various aspects of astronomy and astrophysics, including theory, observation, and instrumentation. The journal publishes high-quality academic papers independently of the techniques used to obtain research results.

《Astronomy and Astrophysics》是一本国际性期刊，专注于天文学和天体物理学的各个方面，包括理论、观测和仪器技术。该期刊独立于用于获得研究结果的技术，发表高质量的学术论文。

Astronomy and Astrophysics

Context: Absorption by molecules in the Earth's atmosphere strongly affects ground-based astronomical observations. The resulting absorption line strength and shape depend on the highly variable physical state of the atmosphere, i.e. pressure, temperature, and mixing ratio of the different molecules involved. Usually, supplementary observations of so-called telluric standard stars (TSS) are needed to correct for this effect, which is expensive in terms of telescope time. We have developed the software package molecfit to provide synthetic transmission spectra based on parameters obtained by fitting narrow ranges of the observed spectra of scientific objects. These spectra are calculated by means of the radiative transfer code LBLRTM and an atmospheric model. In this way, the telluric absorption correction for suitable objects can be performed without any additional calibration observations of TSS. Aims: We evaluate the quality of the telluric absorption correction using molecfit with a set of archival ESO-VLT X-Shooter visible and near-infrared spectra. Methods: Thanks to the wavelength coverage from the U to the K band, X-Shooter is well suited to investigate the quality of the telluric absorption correction with respect to the observing conditions, the instrumental set-up, input parameters of the code, the signal-to-noise of the input spectrum, and the atmospheric profiles. These investigations are based on two figures of merit, I_off and I_res, that describe the systematic offsets and the remaining small-scale residuals of the corrections. We also compare the quality of the telluric absorption correction achieved with moelcfit to the classical method based on a telluric standard star. (Abridged)

W. Kausch

S. Noll

A. Smette

S. Kimeswenger

M. Barden

C. Szyszka

A. M. Jones

H. Sana

H. Horst

F. Kerber

Molecfit: A general tool for telluric absorption correction

Molecfit: 一种用于大气吸收校正的通用工具

Ground-based telescopes equipped with state-of-the-art spectrographs are able to obtain high-resolution transmission and emission spectra of exoplanets that probe the structure and composition of their atmospheres. Various atomic and molecular species, such as Na, CO, H2O have been already detected. Molecular species have been observed only in the near-infrared while atomic species have been observed in the visible. In particular, the detection and abundance determination of water vapor bring important constraints to the planet formation process. We search for water vapor in the atmosphere of the exoplanet HD189733b using a high-resolution transmission spectrum in the visible obtained with HARPS. We use Molecfit to correct for telluric absorption features. Then we compute the high-resolution transmission spectrum of the planet using 3 transit datasets. We finally search for water vapor absorption using a cross-correlation technique that combines the signal of 800 individual lines. Telluric features are corrected to the noise level. We place a 5-sigma upper limit of 100 ppm on the strength of the 6500 A water vapor band. The 1-sigma precision of 20 ppm on the transmission spectrum demonstrates that space-like sensitivity can be achieved from the ground. This approach opens new perspectives to detect various atomic and molecular species with future instruments such as ESPRESSO at the VLT. Extrapolating from our results, we show that only 1 transit with ESPRESSO would be sufficient to detect water vapor on HD189733b-like hot Jupiter with a cloud-free atmosphere. Upcoming near-IR spectrographs will be even more efficient and sensitive to a wider range of molecular species. Moreover, the detection of the same molecular species in different bands (e.g. visible and IR) is key to constrain the structure and composition of the atmosphere, such as the presence of Rayleigh scattering or aerosols.

R. Allart

C. Lovis

L. Pino

A. Wyttenbach

D. Ehrenreich

F. Pepe

Search for water vapor in the high-resolution transmission spectrum of HD 189733b in the visible

在可见光波段对HD 189733b高分辨率透射光谱中水蒸气的搜寻

Transit spectroscopy is the most frequently used technique to reveal the atmospheric properties of exoplanets. At high resolution, it has the added advantage of resolving the small Doppler shift of spectral lines and, thus, the trace signal of the exoplanet atmosphere can be extracted separately. We obtained the transmission spectra of the extrasolar planet WASP-85Ab, a hot Jupiter in a 2.655-day orbit around a G5, V = 11.2 mag host star, observed by the high-resolution spectrograph ESPRESSO at the Very Large Telescope array for three transits. We present an analysis of the Rossiter-McLaughlin (RM) effect on WASP-85A and determine a spin-orbit angle λ = −16.155° −2.879 +2.916 , suggesting that the planet is in a nearly aligned orbit. Combining the transmission spectra of three nights, we tentatively detected H α and Call absorption with ⪆3 σ via direct visual inspection of the transmission spectra with the center-to-limb variation and the Rossiter-McLaughlin effects removed; these absorptions still remain visible after excluding the cores of these strong lines with a 0.1Å mask. These spectral signals appear likely to have originated from the planetary atmosphere, but we cannot fully exclude a stellar origin. Via the cross-correlation analysis of a set of atoms and molecules, Li I is marginally detected at the ∼4 σ level, suggesting that Li might be present in the atmosphere of WASP-85Ab.

Zewen Jiang

Wei Wang

Guo Chen

Fei Yan

Heather M. Cegla

Patricio Rojo

Yaqing Shi

Qinglin Ouyang

Meng Zhai

Yujuan Liu

Fei Zhao

Yuqin Chen

Atmospheric composition of WASP-85Ab with ESPRESSO/VLT observations

使用ESPRESSO/VLT观测的WASP-85Ab的大气成分

Numerical models of photodissociation regions (PDRs) are an essential tool to quantitatively understand observations of massive star forming regions through simulations. Few mature PDR models are available and the Cologne KOSMA- τ PDR model is the only sophisticated model that uses a spherical cloud geometry, thereby allowing us to simulate clumpy PDRs. We present the current status of the code as a reference for modelers and for observers that plan to apply KOSMA- τ to interpret their data. For the numerical solution of the chemical problem, we present a superior Newton-Raphson stepping algorithm and discuss strategies to numerically stabilize the problem and speed up the iterations. The chemistry in KOSMA- τ is upgraded to include the full surface chemistry in an up-to-date formulation and we discuss a novel computation of branching ratios in chemical desorption reactions. The high dust temperature in PDRs leads to a selective freeze-out of oxygen-bearing ice species due to their higher condensation temperatures and we study changes in the ice mantle structures depending on the PDR parameters, in particular the impinging ultraviolet field. Selective freeze-out can produce enhanced C abundances and higher gas temperatures, resulting in a fine-structure line emission of atomic carbon [C i ] enhanced by up to 50% if surface reactions are considered. We show how recent Atacama Large Millimeter Array (ALMA) observations of HCO + emission in the Orion Bar with high spatial resolution on the scale of individual clumps can be interpreted in the context of nonstationary, clumpy PDR ensembles. Additionally, we introduce WL-PDR, a simple plane-parallel PDR model written in Mathematica to act as a numerical testing environment of PDR modeling aspects.

M. Röllig

V. Ossenkopf-Okada

The KOSMA-<i>τ</i>PDR model

KOSMA-<i>τ</i>PDR 模型

Context. Exoplanet atmospheres are the key to understanding the nature of exoplanets. To this end, transit spectrophotometry provides us opportunities to investigate the physical properties and chemical compositions of exoplanet atmospheres. Aims. We aim to detect potential atmospheric signatures in 12 gaseous giant exoplanets using transit spectrophotometry and we try to constrain their atmospheric properties. Methods. The targets of interest were observed using transit spectrophotometry with the GTC OSIRIS instrument. We estimated the transit parameters and obtained the optical transmission spectra of the target planets using a Bayesian framework. We analyzed the spectral features in the transmission spectra based on atmospheric retrievals. Results. Most of the observed transmission spectra were found to be featureless, with only the spectrum of CoRoT-1b showing strong evidence for atmospheric features. However, in combination with the previously published near-infrared transmission spectrum, we found multiple interpretations for the atmosphere of CoRoT-1b due to the lack of decisive evidence for alkali metals or optical absorbers. Conclusions. Featureless spectra are not necessarily indicative of cloudy atmospheres if they poorly constrain the altitudes of cloud decks. Precise constraints on the models of hazes and clouds strongly depend on the significance of the observed spectral features. Further investigations on these exoplanets, especially CoRoT-1b, are required to confirm the properties of their atmospheres.

C. Jiang

G. Chen

E. Pallé

F. Murgas

H. Parviainen

Y. Ma

Featureless transmission spectra of 12 giant exoplanets observed by GTC/OSIRIS

12颗巨型系外行星的无特征透射光谱——基于GTC/OSIRIS的观测

Context . Inferring atmospheric properties of exoplanets from observed spectra is key to understanding their formation, evolution, and habitability. Since traditional Bayesian approaches to atmospheric retrieval (e.g., nested sampling) are computationally expensive, a growing number of machine learning (ML) methods such as neural posterior estimation (NPE) have been proposed. Aims . We seek to make ML-based atmospheric retrieval (1) more reliable and accurate with verified results, and (2) more flexible with respect to the underlying neural networks and the choice of the assumed noise models. Methods . First, we adopted flow matching posterior estimation (FMPE) as a new ML approach to atmospheric retrieval. FMPE maintains many advantages of NPE, but provides greater architectural flexibility and scalability. Second, we used importance sampling (IS) to verify and correct ML results, and to compute an estimate of the Bayesian evidence. Third, we conditioned our ML models on the assumed noise level of a spectrum (i.e., error bars), and thus made them adaptable to different noise models. Results . Both our noise-level-conditional FMPE and NPE models perform on a par with nested sampling across a range of noise levels when tested on simulated data. FMPE trains about three times faster than NPE and yields higher IS efficiencies. IS successfully corrects inaccurate ML results, identifies model failures via low efficiencies, and provides accurate estimates of the Bayesian evidence. Conclusions . FMPE is a powerful alternative to NPE for fast, amortized, and parallelizable atmospheric retrieval. IS can verify results, helping to build confidence in ML-based approaches, while also facilitating model comparison via the evidence ratio. Noise level conditioning allows design studies for future instruments to be scaled up; for example, in terms of the range of signal-to-noise ratios.

Timothy D. Gebhard

Jonas Wildberger

Maximilian Dax

Annalena Kofler

Daniel Angerhausen

Sascha P. Quanz

Bernhard Schölkopf

Flow matching for atmospheric retrieval of exoplanets: Where reliability meets adaptive noise levels

系外行星大气反演中的流匹配：可靠性与自适应噪声水平的交汇

Sympathetic solar flares are eruptions that occur nearby in space and time, driven by an apparent interaction between the active regions in which they are triggered. Their statistical existence on the Sun has yet to be firmly established. The main goal of this paper is to identify a statistical signature of sympathetic flares, characterize their properties, and determine a potential mechanism driving their interaction. We performed a statistical analysis of a large number of flares observed by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO), the Reuven Ramaty High Energy Solar Spectroscopic Imager ( RHESSI ), and the Spectrometer Telescope for Imaging X-rays (STIX) on Solar Orbiter during solar cycle 24 and 25. We examined the spatiotemporal distribution of consecutive flare pairs across solar cycle phases and hemispheres along with the propagation velocity of potential causal interactions and the relationship between flare magnitudes. We observed an excess of hemispheric flares separated by about 30 degrees of longitude and triggered in less than 1.5 hours from each other. This peak in angular separation varies with the solar cycle phase and hemisphere. Moreover, we identified a deficit of transequatorial events separated by 25-30 degrees in latitude and less than 5 degrees in longitude, a phenomenon we term unsympathetic flares. We provide strong statistical evidence for the existence of sympathetic flares on the Sun, demonstrating that their occurrence rate reaches approximately 5% across the three instruments used in this study. Additionally, we propose an interpretation of the observed angular scale of the sympathetic phenomenon based on the separation between magnetic field line footpoints derived from potential field source surface extrapolations.

L-S. Guité

A. Strugarek

P. Charbonneau

Flaring together: A preferred angular separation between sympathetic flares on the Sun

共耀：太阳上同源耀斑之间的优选角间距

The Zwicky Transient Facility SN Ia Data Release 2 (ZTF SN Ia DR2) contains more than 3,000 Type Ia supernovae (SNe Ia), providing the largest homogeneous low-redshift sample of SNe Ia. Having at least one spectrum per event, this data collection is ideal for large-scale statistical studies of the photometric, spectroscopic and host-galaxy properties of SNe Ia, particularly of the rarer `peculiar' sub-classes. In this paper we first present the method we developed to spectroscopically classify the SNe in the sample, and the techniques we used to model their multi-band light curves and explore their photometric properties. We then show a method to distinguish between the peculiar sub-types and the normal SNe Ia. We also explore the properties of their host galaxies and estimate their relative rates, focusing on the peculiar sub-types and their connection to the cosmologically useful SNe Ia. Finally, we discuss the implications of our study with respect to the progenitor systems of the peculiar SN Ia events.

G. Dimitriadis

U. Burgaz

M. Deckers

K. Maguire

J. Johansson

M. Smith

M. Rigault

C. Frohmaier

J. Sollerman

L. Galbany

Y.-L. Kim

C. Liu

A. Miller

P.E. Nugent

A. Alburai

P. Chen

S. Dhawan

M. Ginolin

A. Goobar

S.L. Groom

L. Harvey

W.D. Kenworthy

S.R. Kulkarni

K. Phan

B. Popovic

R.L. Riddle

B. B

T.E. Muller-Bravo

J. Nordin

J.H. Terwel

A. Townsend

ZTF SN Ia DR2: The diversity and relative rates of the thermonuclear supernova population

ZTF SN Ia DR2：热核超新星种群的多样性与相对发生率

The interaction between waves and particles is crucial for particle acceleration near interplanetary shocks. Previously, research on these processes was constrained by limited data and the coarse time resolution of interplanetary missions. However, recent high-resolution observations from the Solar Orbiter mission are providing new insights into this area. We analyzed data measured by the Energetic Particle Detector, the Magnetometer, and the Solar Wind Analyzer on board Solar Orbiter, to investigate wave-proton interactions upstream an interplanetary shock observed on April 8, 2022. We performed a mean-field-transformed wavelet analysis on the magnetic field data to derive the wave properties. We reconstructed pitch angle distributions and gyrophase distributions in the solar wind frame of reference to analyze the proton behavior. We find that the observed waves are quasi-parallel propagating, ion-scale transverse waves that exhibit alternating left-handed and right-handed polarization. Fluxes of suprathermal protons oscillate quasi-periodically with these waves and show signs of wave modulation. In addition, signatures hinting at resonance, such as phase shifts across energy, are revealed in proton fluxes. The proton phase space density near the calculated resonant energy increases during the interaction, which indicates the acceleration or scattering of protons. We present direct observations of particles resonating with waves close to an interplanetary shock, which captures these dynamics within single wave periods. Our results highlight the role of wave-particle interactions in dynamic processes occurring in the inner heliosphere.

Xing-Yu Li

Liu Yang

Verena Heidrich-Meisner

Robert F. Wimmer-Schweingruber

Qiu-Gang Zong

Linghua Wang

Lars Berger

Erik Jentsch

Duncan Keilbach

Maximilian Hecht

Javier Rodríguez-Pacheco

Resonant interactions between suprathermal protons and ion-scale waves near an interplanetary shock

Abbreviation	A&A
Journal Impact	5.53
Quartiles(Global)	ASTRONOMY & ASTROPHYSICS(Q1)

ISSN	0004-6361, 1432-0746
h-index	344
Top Journals	Yes

Publication Information	Publisher: EDP Sciences，Publishing cycle: Weekly，Journal Type: journal，Open Access Journals: No
Basic data	Year of publication: 1990，Proportion of original research papers: 99.91%，Self Citation Rate:31.50%， Gold OA Rate: 62.90%
Average review cycle	网友分享经验：超快,1-2周
Average recruitment ratio	网友分享经验：较易

Astronomy and Astrophysics

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