Astronomy & Astrophysics最新文献

{"title":"Asteroid (4337) Arecibo: Two ice-rich bodies forming a binary","authors":"Ziyu Liu, Daniel Hestroffer, Josselin Desmars, Pedro David","doi":"10.1051/0004-6361/202450586","DOIUrl":"https://doi.org/10.1051/0004-6361/202450586","url":null,"abstract":"<i>Context.<i/> Binary asteroids are present in all populations of the Solar System, from near-Earth to trans-Neptunian regions. As is true for the small Solar System bodies (SSSBs), binary asteroids generally offer valuable insights into the formation of the Solar System, as well as its collisions and dynamic evolution. In particular, the binaries provide fundamental quantities and properties of these SSSBs, such as mass, angular momentum, and density, all of which are often hidden. The direct measurement of densities and porosities is of great value in revealing the gravitational aggregates and icy bodies that form the asteroid-comet continuum.<i>Aims.<i/> Several observation techniques from space and ground-based platforms have provided many results in this regard. Here we show the value of the <i>Gaia<i/> mission and its high-precision astrometry for analysing asteroid binaries and for individually deriving the masses of the components.<i>Methods.<i/> We focus on the binary asteroid (4337) Arecibo, a member of the Themis family. We analysed the astrometry obtained in the <i>Gaia<i/> FPR catalogue release, and performed orbital fitting for both the heliocentric orbit of the system and the relative orbit of the binary components.<i>Results.<i/> We obtain an estimation of the component masses and their flux ratio, and derive bulk densities <i>ρ<i/><sub>1<sub/> ≈ 1.2 and <i>ρ<i/><sub>2<sub/> ≈ 1.6 for the primary and the secondary, respectively. The results are consistent with an ice-rich body in the outer main belt. They also show a significantly denser secondary or a less closely packed primary. Constraints on these densities and on macroscopic porosities are nevertheless limited by our poor knowledge of the sizes of the components. Observations of future mutual events, and of stellar occultations predicted in 2024–2025, will be essential for improving our knowledge of this system and its formation.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141973937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-transition study of methanol towards NGC 1068 with ALMA","authors":"K.-Y. Huang, D. Abbink, S. Viti, S. García-Burillo","doi":"10.1051/0004-6361/202348779","DOIUrl":"https://doi.org/10.1051/0004-6361/202348779","url":null,"abstract":"<i>Context.<i/> The outflowing molecular gas in the circumnuclear disc (CND) of the nearby (<i>D<i/> = 14 Mpc) AGN-starburst composite galaxy NGC 1068 is considered as a manifestation of ongoing AGN feedback. The large spread of velocities from the outflowing gas is likely driving various kinds of shock chemistry across the CND.<i>Aims.<i/> We performed a multiline molecular study using CH<sub>3<sub/>OH with the aim of characterizing the gas properties probed by CH<sub>3<sub/>OH in the CND of NGC 1068 and investigating its potential association with molecular shocks.<i>Methods.<i/> Multi-transition CH<sub>3<sub/>OH were imaged at the resolution of with the Atacama Large Millimeter/submillimeter Array (ALMA). We performed a non-LTE radiative transfer analysis coupled with a Bayesian inference process in order to determine the gas properties such as the gas volume density and the gas kinetic temperature.<i>Results.<i/> The gas densities traced by CH<sub>3<sub/>OH point to ∼10<sup>6<sup/> cm<sup>–3<sup/> across all the CND regions. The gas kinetic temperature cannot be well constrained in any of the CND regions, though the inferred temperature is likely low (≲100 K).<i>Conclusions.<i/> The low gas temperature traced by CH<sub>3<sub/>OH suggests shocks and subsequent fast cooling as the origin of the observed gas-phase CH<sub>3<sub/>OH abundance. We also note that the E-/A-isomer column-density ratio inferred is fairly close to unity, which is, interestingly, different from the Galactic measurements in the literature. It remains inconclusive whether CH<sub>3<sub/>OH exclusively traces slow and non-dissociative shocks, or whether the CH<sub>3<sub/>OH abundance can actually be boosted in both fast and slow shocks.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141973935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Secular aberration drift in stellar proper motions","authors":"N. Liu, Z. Zhu, J.-C. Liu","doi":"10.1051/0004-6361/202451053","DOIUrl":"https://doi.org/10.1051/0004-6361/202451053","url":null,"abstract":"<i>Context.<i/> The motion of the Solar System barycenter (SSB), the spatial origin of the International Celestial Reference System, causes a directional displacement known as secular aberration. The secular aberration drift caused by the galactocentric acceleration of the SSB has been modeled in the third generation of the International Celestial Reference Frame.<i>Aims.<i/> We aim to address another secular aberration drift effect due to the change in the line-of-sight direction and study its implications for stellar proper motions.<i>Methods.<i/> We derived a complete formula for the secular aberration drift and computed its influence on stellar proper motion based on the astrometric data in <i>Gaia<i/> Data Release 3.<i>Results.<i/> We find that the secular aberration drift due to the change in the line-of-sight direction tends to decrease the observed proper motions for stars with galactic longitudes between 0° and 180°, and increase the observed proper motion for stars in the remaining region. If this secular aberration drift effect is ignored, it will induce an additional proper motion of > 1 mas yr<sup>−1<sup/> for 84 stars and > 0.02 mas yr<sup>−1<sup/> for 5 944 879 stars, which is comparable to or several times greater than the typical formal uncertainty of the <i>Gaia<i/> proper motion measurements at <i>G<i/> < 13.<i>Conclusions.<i/> The secular aberration drift due to the change in the line-of-sight direction and the acceleration of the SSB should be modeled to make the stellar reference frame consistent with the extragalactic reference frame.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141973938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Self-similar cluster structures in massive star-forming regions: Isolated evolution from clumps to embedded clusters","authors":"Jian-wen Zhou, Pavel Kroupa, Sami Dib","doi":"10.1051/0004-6361/202450412","DOIUrl":"https://doi.org/10.1051/0004-6361/202450412","url":null,"abstract":"We used the dendrogram algorithm to decompose the surface density distributions of stars into hierarchical structures. These structures were tied to the multiscale structures of star clusters. A similar power-law for the mass-size relation of star clusters measured at different scales suggests a self-similar structure of star clusters. We used the minimum spanning tree method to measure the separations between clusters and gas clumps in each massive star-forming region. The separations between clusters, between clumps, and between clusters and clumps were comparable, which indicates that the evolution from clump to embedded cluster proceeds in isolation and locally, and does not affect the surrounding objects significantly. By comparing the mass functions of the ATLASGAL clumps and the identified embedded clusters, we confirm that a constant star formation efficiency of ≈0.33 can be a typical value for the ATLASGAL clumps.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141973805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"X-Shooting ULLYSES: Massive stars at low metallicity","authors":"H. Sana, F. Tramper, M. Abdul-Masih, R. Blomme, K. Dsilva, G. Maravelias, L. Martins, A. Mehner, A. Wofford, G. Banyard, C. L. Barbosa, J. Bestenlehner, C. Hawcroft, D. John Hillier, H. Todt, C. J. K. Larkin, L. Mahy, F. Najarro, V. Ramachandran, M. C. Ramírez-Tannus, M. M. Rubio-Díez, A. A. C. Sander, T. Shenar, J. S. Vink, F. Backs, S. A. Brands, P. Crowther, L. Decin, A. de Koter, W.-R. Hamann, C. Kehrig, R. Kuiper, L. Oskinova, D. Pauli, J. Sundqvist, O. Verhamme","doi":"10.1051/0004-6361/202347479","DOIUrl":"https://doi.org/10.1051/0004-6361/202347479","url":null,"abstract":"<i>Context<i/>. The XShootU project aims to obtain ground-based optical to near-infrared spectroscopy of all targets observed by the <i>Hubble<i/> Space Telescope (HST) under the Director’s Discretionary program ULLYSES. Using the medium-resolution spectrograph X-shooter, spectra of 235 OB and Wolf-Rayet (WR) stars in subsolar metallicity environments have been secured. The bulk of the targets belong to the Large and Small Magellanic Clouds, with the exception of three stars in NGC 3109 and Sextans A.<i>Aims<i/>. This second paper in the series focuses on the optical observations of Magellanic Clouds targets. It describes the uniform reduction of the UVB (300–560 nm) and VIS (550–1020 nm) XShootU data as well as the preparation of advanced data products that are suitable for homogeneous scientific analyses.<i>Methods<i/>. The data reduction of the RAW data is based on the ESO CPL X-shooter pipeline. We paid particular attention to the determination of the response curves. This required equal flat-fielding of the science and flux standard star data and the derivation of improved flux standard models. The pipeline products were then processed with our own set of routines to produce a series of advanced data products. In particular, we implemented slit-loss correction, absolute flux calibration, (semi-)automatic rectification to the continuum, and a correction for telluric lines. The spectra of individual epochs were further corrected for the barycentric motion, re-sampled and co-added, and the spectra from the two arms were merged into a single flux-calibrated spectrum covering the entire optical range with maximum signal-to-noise ratio.<i>Results<i/>. We identify and describe an undocumented recurrent ghost visible on the RAW data. We present an improved flat-fielding strategy that limits artifacts when the SCIENCE and FLUX standard stars are observed on different nights. The improved FLUX standard models and the new grid of anchor points limit artifacts of the response curve correction, for example on the shape of the wings of the Balmer lines, from a couple of per cent of the continuum level to less than 0.5%. We confirm the presence of a radial velocity shift of about 3.5 km s<sup>−1<sup/> between the UVB and the VIS arm of X-shooter and that there are no short term variations impacting the RV measurements. RV precision better than 1 km s<sup>-1<sup/> can be obtained on sharp telluric lines while RV precision on the order of 2 to 3 km s<sup>-1<sup/> is obtained on data with the best S/N.<i>Conclusions<i/>. For each target observed by XShootU, we provide three types of data products: (i) two-dimensional spectra for each UVB and VIS exposure before and after correction for the instrument response; (ii) one-dimensional UVB and VIS spectra as produced by the X-shooter pipeline before and after response-correction, and applying various processing, including absolute flux calibration, telluric removal, normalization and barycentric correction; and (i","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141973837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new understanding of the Gemini-Monoceros X-ray enhancement from discoveries with eROSITA","authors":"J. R. Knies, M. Sasaki, W. Becker, T. Liu, G. Ponti, P. P. Plucinsky","doi":"10.1051/0004-6361/202348834","DOIUrl":"https://doi.org/10.1051/0004-6361/202348834","url":null,"abstract":"<i>Aims.<i/> The Gemini-Monoceros X-ray enhancement is a rich field for studying diffuse X-ray emission and supernova remnants (SNRs). Most SNRs in this part of the sky are notoriously difficult to observe due to their large extent. With the launch of the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) on board the Spektrum-Röntgen-Gamma platform in 2019, we are now able to fully study those objects for the first time with CCD resolution. Many of the SNRs in the vicinity are suspected to be very old remnants, which are severely understudied in X-rays due to numerous observational challenges. In addition, the identification of new faint large SNRs might help to solve the long-standing discrepancy between the observed and expected number of Galactic SNRs.<i>Methods.<i/> We performed a detailed X-ray spectral analysis of the entire Gemini-Monoceros X-ray enhancement and a detailed background analysis of the vicinity, which allowed us to model the background with a high precision inside the X-ray enhancement. We also made use of multiwavelength data to better understand the morphology and to constrain the distances to the different sources. Based on the spectral analysis, we estimated the properties of the sources and calculated a grid of model SNRs to determine the individual SNR properties.<i>Results.<i/> Most of the diffuse plasma of the Monogem Ring SNR is well described by a single nonequilibrium ionization (NEI) component with an average temperature of <i>kT =<i/> 0.14 ± 0.03 keV. We obtain an age of ≈1.2 × 10<sup>5<sup/> yr – consistent with PSR B0656+14 – for the Monogem Ring and an explosion energy typical for a core-collapse (CC) supernova (SN). In the southeast, we found evidence for a significant temperature enhancement and a second plasma component. Our findings show that a scenario of two SNRs at ≈300 pc is likely, with the new candidate having an age of ≈50 000 yr. We were also able to improve on previous results for the Monoceros Loop and PKS 0646+06 SNRs by disentangling the foreground diffuse emission of the Monogem Ring SNR. We obtained significantly higher temperatures than previous studies, and for PKS 0646+06 a much lower estimated age of the SNR. We also found a new SNR candidate G190.4+12.5 which most likely is located at <i>D<i/> > 1.5 kpc, expanding into a low density medium at a high distance from the Galactic plane, with an estimated age of 40 000–60 000 yr.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141973840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-thermal radio emission in Sakurai’s Object","authors":"M. Hajduk, P. A. M. van Hoof, A. A. Zijlstra, G. Van de Steene, S. Kimeswenger, D. Barría, D. Tafoya, J. A. Toalá","doi":"10.1051/0004-6361/202450496","DOIUrl":"https://doi.org/10.1051/0004-6361/202450496","url":null,"abstract":"<i>Context.<i/> The very late thermal pulse (VLTP) affects the evolution of ∼20% of 1–8 <i>M<i/><sub>⊙<sub/> stars, repeating the last red giant phases within a few years and leading to the formation of a new, but hydrogen-poor, nebula within the old planetary nebula. The strong dust formation in the latter obscures the optical and near-infrared radiation of the star.<i>Aims.<i/> We aimed to determine the reheating timescale of the central star in Sakurai’s Object, which is an important constraint for the poorly understood VLTP evolution.<i>Methods.<i/> We observed the radio continuum emission of Sakurai’s Object for almost 20 years, from 2004 to 2023. Continuous, multi-frequency observations proved to be essential for distinguishing between phases dominated by photoionization and shock ionization.<i>Results.<i/> The flux density fluctuates by more than a factor of 40 within months to years. The spectral index remained negative between 2006 and 2017 and has been close to zero since 2019. The emission region has been only barely resolved since 2021.<i>Conclusions.<i/> Non-thermal radio emission observed from 2004 to 2017 traces shocks induced by wind interactions due to discrete mass-loss events. Thermal emission dominates from 2019 to 2023 and may indicate photoionization of the nebula by the central star.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141973839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Confronting sparse Gaia DR3 photometry with TESS for a sample of around 60 000 OBAF-type pulsators★★★","authors":"Daniel Hey, Conny Aerts","doi":"10.1051/0004-6361/202450489","DOIUrl":"https://doi.org/10.1051/0004-6361/202450489","url":null,"abstract":"<i>Context.<i/> The <i>Gaia<i/> mission has delivered hundreds of thousands of variable star light curves in multiple wavelengths. Recent work demonstrates that these light curves can be used to identify (non-)radial pulsations in OBAF-type stars, despite their irregular cadence and low light curve precision, of the order of a few millimagnitudes. With the considerably more precise TESS photometry, we revisited these candidate pulsators to conclusively ascertain the nature of their variability.<i>Aims.<i/> We seek to re-classify the <i>Gaia<i/> light curves with the first two years of TESS photometry for a sample of 58 970 <i>p<i/>- and <i>g<i/>-mode pulsators, encompassing <i>γ<i/> Dor, <i>δ<i/> Scuti, slowly pulsating B, and <i>β<i/> Cep variables. From the TESS data, we seek to assess the quality of <i>Gaia<i/>’s classification of non-radial pulsators, which is based on sparse, years-long light curves of millimagnitude precision. We also supply four new catalogues containing the confirmed pulsators, along with their dominant and secondary pulsation frequencies, the number of independent mode frequencies, and a ranking according to their usefulness for future asteroseismic ensemble analysis.<i>Methods.<i/> We first analysed the TESS light curves independent of their <i>Gaia<i/> classification by pre-whitening all dominant pulsation modes down to a 1% false alarm probability. Using this, in combination with a feature-based random forest classifier, we identified different variability types across the sample.<i>Results.<i/> We find that the <i>Gaia<i/> photometry is exceptionally accurate for detecting the dominant and secondary frequencies, reaching approximately 80% accuracy in frequency for <i>p<i/>- and <i>g<i/>-mode pulsators. The majority of <i>Gaia<i/> classifications are consistent with the classifications from the TESS data, illustrating the power of the low-cadence <i>Gaia<i/> photometry for pulsation studies. We find that the sample of <i>g<i/>-mode pulsators forms a continuous group of variable stars along the main sequence across B, A, and F spectral types, implying that the mode excitation mechanisms for all these pulsators need to be updated with improved physics. Finally, we provide a rank-ordered table of pulsators according to their asteroseismic potential for follow-up studies, based on the number of sectors they have been observed in, their classification probability, and the number of independent modes found in the TESS light curves from the nominal mission.<i>Conclusions.<i/> Our catalogue offers a major increase in the number of confirmed <i>g<i/>-mode pulsators with an identified dominant mode suitable for follow-up TESS ensemble asteroseismology of such stars.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141973936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation of planetary atmospheres","authors":"Ryushi Miyayama, Hiroshi Kobayashi","doi":"10.1051/0004-6361/202450177","DOIUrl":"https://doi.org/10.1051/0004-6361/202450177","url":null,"abstract":"To investigate impact vaporization for planetary atmosphere formation, we have studied the thermodynamic state generated by the shock wave due to a high-velocity impact, called the shock field. We have carried out iSALE simulations for high-velocity vertical impacts using ANEOS for an equation-of-state (EoS) model. To understand the shock fields obtained from simulations, we have investigated the contribution of the thermal and cold terms in the EoS model on the Hugoniot curves. Although the thermal and cold terms are important for the pressure, the internal energy is mainly determined by the thermal term. We thus assume a simple EoS determined by the thermal term and then analytically derive the shock internal-energy field, which reproduces the results of simulations well. Using the analytical solution of internal energy and the Hugoniot curve, we have derived the shock pressure field analytically as well. The analytical solutions for internal energy and pressure are valid even for impact velocities as low as the sound speed. The solution is good for the vertical direction or within the angles of about 60 degrees. We have applied the solution to impact vaporization for the formation of planetary atmospheres. This gives good estimation of reformation of the planetary atmospheres of Earth sized planet.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142225771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GASTLI","authors":"L. Acuña, L. Kreidberg, M. Zhai, P. Mollière","doi":"10.1051/0004-6361/202450559","DOIUrl":"https://doi.org/10.1051/0004-6361/202450559","url":null,"abstract":"The metal mass fractions of gas giants are a powerful tool for constraining their formation mechanisms and evolution. The metal content is inferred by comparing mass and radius measurements with interior structure and evolution models. In the midst of the JWST, CHEOPS, TESS, and the forthcoming PLATO era, we are at the brink of obtaining unprecedented precision in radius, age, and atmospheric metallicity measurements. To prepare for this wealth of data, we present the GAS gianT modeL for Interiors (GASTLI), an easy-to-use, publicly available Python package. The code is optimized to rapidly calculate mass-radius relations, and radius and luminosity thermal evolution curves for a variety of envelope compositions and core mass fractions. Its applicability spans planets with masses of 17 <i>M<i/><sub>⊕<sub/> < <i>M <<i/> 6 <i>M<i/><sub>Jup<sub/>, and equilibrium temperatures of <i>T<i/><sub>eq<sub/> <i><<i/> 1000 K. The interior model is stratified in a core composed of water and rock, and an envelope constituted by H/He and metals (water). The interior is coupled to a grid of self-consistent, cloud-free atmospheric models to determine the atmospheric and boundary interior temperature, as well as the contribution of the atmosphere to the total radius. We successfully validate GASTLI by comparing it to previous work and data of the gas giants of the Solar System and Neptune. We also test GASTLI on the Neptune-mass exoplanet HAT-P-26 b, finding a bulk metal mass fraction of between 0.60 and 0.78 and a core mass of 8.5–14.4 <i>M<i/><sub>⊕<sub/>. Finally, we explore the impact of different equations of state and assumptions, such as C/O ratio and transit pressure, in the estimation of bulk metal mass fraction. These differences between interior models entail a change in radius of up to 2.5% for Jupiter-mass planets, but of more than 10% for Neptune-mass. These are equivalent to variations in core mass fraction of 0.07, or 0.10 in envelope metal mass fraction.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":6.5,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141891838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}