Astronomy & Astrophysics最新文献

{"title":"New orbital periods of high-inclination dwarf novae based on Gaia Alerts photometry","authors":"C. Sáez-Carvajal, N. Vogt, M. Zorotovic, J. García-Veas, G. Aravena-Rojas, L. Dumond, F. Figueroa-Tapia, Y. López-Bonilla, A. Rodríguez-Jiménez, I. Vega-Manubens, B. Grawe","doi":"10.1051/0004-6361/202451661","DOIUrl":"https://doi.org/10.1051/0004-6361/202451661","url":null,"abstract":"The orbital period of a cataclysmic variable stands as a crucial parameter for investigating the structure and physics of these binary systems, as well as understanding their evolution. We use photometric <i>Gaia<i/> data for dwarf novae (DNe) in the quiescent state – which are available for a number of years – to determine new orbital periods and improve or modify previously suggested period values. Two approaches are implemented for selecting high-inclination targets, either eclipsing or with ellipsoidal variations. We determine new orbital periods for 75 DNe and improve ephemerides for 27 more (three of which change significantly), contributing 9.4% of the known DNe periods of between 0.05 and 2.0 days, and doubling the number of known periods exceeding 0.44 days. Their phase-folded light curves are presented and arranged by orbital period, illustrating the transition from short-period systems, dominated by radiation from the accretion disc and the hot spot, to longer-period DNe, where the Roche-lobe-filling secondary star is the primary visual flux source. This transition – which occurs around the well-known period gap (between ∼2 and 3 hours) – is expected, as DNe with larger orbital periods typically harbour more massive donors, which contribute to the visible flux. However, this transition is not abrupt. Within the same range of periods, we observe systems dominated by ellipsoidal variations, where the companion star is clearly visible, as well as others dominated by the disc and the hot spot. The presence of some DNe with ellipsoidal variations near the lower edge of the period gap is striking, as the companions in these systems are expected to be cool low-mass M-dwarfs not visible in the light curve. This could indicate that we are observing systems where the donor star was originally much more massive and underwent significant nuclear evolution before mass-transfer began, as has been suggested previously for QZ Ser.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"170 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673924","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":"Temporal and chromatic variation of polarized scattered light in the outer disk of PDS 70⋆","authors":"J. Ma, C. Ginski, R. Tazaki, C. Dominik, H. M. Schmid, F. Ménard","doi":"10.1051/0004-6361/202451614","DOIUrl":"https://doi.org/10.1051/0004-6361/202451614","url":null,"abstract":"<i>Context.<i/> PDS 70 stands out as the only system hosting a protoplanetary disk and two confirmed planets undergoing formation. It is a unique target for characterizing the dust in this type of disk.<i>Aims.<i/> We aim to accurately measure the reflected polarized intensity and quantify the variability and asymmetry for PDS 70 across multiple epochs and wavelengths in the optical and near-infrared. We present new high-contrast polarimetric differential imaging observations of PDS 70, with the <i>N<i/>_<i>R<i/> filter on SPHERE/ZIMPOL.<i>Methods.<i/> We combined the new observation with archival data of the VLT/SPHERE instrument, spanning five wavelengths (<i>N<i/>_<i>R<i/>, <i>V<i/><i>B<i/><i>B<i/>, <i>J<i/>, <i>H<i/>, and <i>K<i/><i>s<i/>) over seven epochs and eight years. For each observational epoch, we corrected the smearing effect due to finite instrument resolution, measured the azimuthal brightness profiles, and derived the intrinsic disk-integrated polarized reflectivity and the intrinsic brightness contrasts.<i>Results.<i/> With our homogeneous analysis of all available optical and near-infrared data sets of the disk around PDS 70, we find significant temporal variability of the integrated polarized reflectivity as well as the azimuthal brightness profile. This indicates variable shadowing on the outer disk by inner disk structures beyond the resolution limit of current imaging instruments. Despite these variabilities, we observe a systematic wavelength-dependent contrast between the near side and the far side of the inclined disk. These results underline the importance of considering both the shadowing effect from the inner disk and the surface geometry of the observed reflecting disk in the analysis and interpretation of observational data.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"23 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673921","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":"Abnormal Stokes V profiles observed by Hinode in a sunspot","authors":"H. Hamedivafa, R. Rezaei","doi":"10.1051/0004-6361/202450625","DOIUrl":"https://doi.org/10.1051/0004-6361/202450625","url":null,"abstract":"<i>Context.<i/> Hidden magnetic components in a sunspot are present as small-scale structures that are absent in low-resolution observations.<i>Aims.<i/> We search for traces of the hidden magnetic components in spectro-polarimetric observations of a mature sunspot close to the disk center recorded by Hinode.<i>Methods.<i/> To find extra humps in the far blue and red lobes of Stokes <i>V<i/>, we examined the sign reversal in the second derivative of the profile in the umbra and penumbra. We also looked for the hump signature in the Stokes <i>I<i/> and the linear polarization profiles.<i>Results.<i/> The amplitudes of the humps are small compared to the main component. More than half of the profiles show one extra hump, while 21% show an extra hump on both the blue and the red lobe of the 630.15 nm line with the same magnetic polarity as the sunspot. The location of the pixels where the extra hump is seen on both lobes has a pseudo-grainy structure in the single wavelength Stokes <i>V<i/> magnetograms. This type of profile is better detected in darker parts of the penumbra, as well as in the umbra-penumbra border toward the umbra. The spectral distance between the two humps averaged over elliptical rings levels off in the umbra, decreases toward the penumbra, and levels off again there. We find no correlations between the wavelength positions of the two humps.<i>Conclusions.<i/> We discuss two scenarios that could potentially produce the simultaneously observed blue and red humps: one in which a single hidden magnetic component is responsible for the two humps, and another in which the two humps emanate from two hidden magnetic components.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"74 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673922","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":"Comparing the interstellar and circumgalactic origin of gas in the tails of jellyfish galaxies","authors":"Martin Sparre, Christoph Pfrommer, Ewald Puchwein","doi":"10.1051/0004-6361/202450544","DOIUrl":"https://doi.org/10.1051/0004-6361/202450544","url":null,"abstract":"Simulations and observations have found long tails in ‘jellyfish galaxies’, which are commonly thought to originate from ram-pressure stripped gas of the interstellar medium (ISM) in the immediate galactic wake. At larger distances from the galaxy, the long tails have been claimed to form in situ, owing to thermal instability and fast radiative cooling of mixed ISM and intracluster medium (ICM). In this paper, we use magnetohydrodynamical wind tunnel simulations of a galaxy with the AREPO code to study the origin of gas in the tails of jellyfish galaxies. To this end, we modelled the galaxy orbit in a cluster by accounting for a time-varying galaxy velocity, ICM density, and the turbulent magnetic field. By tracking gas flows between the ISM, the circumgalactic medium (CGM), and the ICM, we find – contrary to popular opinion – that the majority of the gas in the tail originates in the CGM. Prior to the central passage of the jellyfish galaxy in the cluster, the CGM is directly transported to the clumpy jellyfish tail that has been shattered into small cloudlets. After the central cluster passage, gas in the tail originates both from the initial ISM and the CGM, but that from the latter is accreted onto the galactic ISM before being ram-pressure stripped to form filamentary tentacles in the tail. Our simulation shows a declining gas metallicity in the tail as a function of downstream distance from the galaxy. We conclude that the CGM plays an important role in shaping the tails of jellyfish galaxies.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"69 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673933","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":"Driven two-fluid slow magnetoacoustic waves in the solar chromosphere with a realistic ionisation profile","authors":"R. Niedziela, K. Murawski, S. Poedts","doi":"10.1051/0004-6361/202449941","DOIUrl":"https://doi.org/10.1051/0004-6361/202449941","url":null,"abstract":"<i>Context.<i/> This study was carried out in the context of chromosphere heating.<i>Aims.<i/> This paper aims to discuss the evolution of driven slow magnetoacoustic waves (SMAWs) in the solar chromosphere modelled with a realistic ionisation profile and to consider their potential role in plasma heating and the generation of plasma outflows.<i>Methods.<i/> Two-dimensional (2D) numerical simulations of the solar atmosphere are performed using the JOANNA code. The dynamic behaviour of the atmospheric plasma is governed by the two-fluid equations (with ionisation and recombination terms taken into account) for neutrals (hydrogen atoms) and ions (protons)+electrons. The initial atmosphere is described by a hydrostatic equilibrium (HE) supplemented by the Saha equation (SE) and embedded in a fanning magnetic field. This initial equilibrium is perturbed by a monochromatic driver which operates in the chromosphere on the vertical components of the ion and neutral velocities.<i>Results.<i/> Our work shows that the HE+SE model results in time-averaged (net) plasma outflows in the top chromosphere, which are larger than their pure HE counterpart. The parametric studies demonstrate that the largest chromosphere temperature rise occurs for smaller wave driving periods. The plasma outflows exhibit the opposite trend, growing with the driver period.<i>Conclusions.<i/> We find that the inclusion of the HE+SE plasma background plays a key role in the evolution of SMAWs in the solar atmosphere.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"36 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670325","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":"Multiple reference star differential imaging with VLT/SPHERE","authors":"C. Romero, J. Milli, A.-M. Lagrange, R. De Rosa, S. Ertel, C. del Burgo","doi":"10.1051/0004-6361/202346361","DOIUrl":"https://doi.org/10.1051/0004-6361/202346361","url":null,"abstract":"<i>Context<i/>. High-contrast imaging observations mostly rely on angular differential imaging, a successful technique for detecting point-sources, such as planets. However, in the vicinity of the star (typically below 300 mas), this technique suffers from signal self-subtraction when there is not enough field rotation. Building large libraries of reference stars from archival data later used to optimally subtract the stellar halo is a powerful technique known as reference star differential imaging (RSDI) that can overcome this limitation.<i>Aims<i/>. We aim at investigating new methods for creating reference libraries composed of multiple stars when applying reference star differential imaging to VLT/SPHERE data. We used for that purpose a data set from the SPHERE High Angular Resolution Debris Disk Survey (SHARDDS), composed of 55 targets observed in broad-band H with the InfraRed Dual-band Imager and Spectrograph (IRDIS) during 2015-2016, with a total of ~20 000 frames. We consider HD 206893, known to host a close-in bound substellar companion HD 206893 B, as a benchmark science target to demonstrate the improved sensitivity provided by this method.<i>Methods<i/>. We created libraries of reference frames based on different image similarity metrics: the cosine distance between descriptors created by a convolutional neural network, the Pearson correlation coefficient, the Structural Similarity Index, the Strehl ratio, and raw contrast criteria. We used principal component analysis (PCA) to subtract the stellar halo and tested various normalization options.<i>Results<i/>. We obtained the best signal-to-noise ratio (S/N) on HD 206893 B by using the Pearson correlation coefficient (PCC) applied to an annulus between 245 and 612 mas to select reference frames. The ten reference libraries with the highest S/N on the substellar companion HD 206893 B were all based on the PCC method, outperforming other similarity metrics. While the Strehl ratio is the environment variable most correlated to the contrast, it is insufficient to select similar images. We also show that having multiple reference stars in the reference library produces better results than using a single well-chosen reference star.<i>Conclusions<i/>. Using the Pearson correlation computed on a specific area of interest to select reference frames is a promising alternative to improve the detectability of faint point-sources when applying reference star differential imaging. In the future, reducing all the data available in the SPHERE archive using this technique might offer interesting results in the search for previously undetected planets.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"250 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670328","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":"Generative models of astrophysical fields with scattering transforms on the sphere","authors":"L. Mousset, E. Allys, M. A. Price, J. Aumont, J.-M. Delouis, L. Montier, J. D. McEwen","doi":"10.1051/0004-6361/202451396","DOIUrl":"https://doi.org/10.1051/0004-6361/202451396","url":null,"abstract":"Scattering transforms are a new type of summary statistics recently developed for the study of highly non-Gaussian processes, which have been shown to be very promising for astrophysical studies. In particular, they allow one to build generative models of complex non-linear fields from a limited amount of data and have been used as the basis of new statistical component separation algorithms. In the context of upcoming cosmological surveys, such as LiteBIRD for the cosmic microwave background polarisation or the <i>Vera C. Rubin<i/> Observatory and the <i>Euclid<i/> space telescope for study of the large-scale structures of the Universe, extending these tools to spherical data is necessary. In this work, we developed scattering transforms on the sphere and focused on the construction of maximum-entropy generative models of several astrophysical fields. We constructed, from a single target field, generative models of homogeneous astrophysical and cosmological fields, whose samples were quantitatively compared to the target fields using common statistics (power spectrum, pixel probability density function, and Minkowski functionals). Our sampled fields agree well with the target fields, both statistically and visually. We conclude, therefore, that these generative models open up a wide range of new applications for future astrophysical and cosmological studies, particularly those for which very little simulated data is available.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"17 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670333","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":"Depth profiling of implanted D+ in silicates: Contribution of solar wind protons to water in the Moon and terrestrial planets","authors":"Xiandi Zeng, Hong Tang, Xiongyao Li, Chuanjiao Zhou, Sen Hu, Xiaojia Zeng, Wen Yu, Yuanyun Wen, Yanxue Wu, Bing Mo, Jianzhong Liu, Yong Fu","doi":"10.1051/0004-6361/202450879","DOIUrl":"https://doi.org/10.1051/0004-6361/202450879","url":null,"abstract":"<i>Context<i/>. The solar wind protons implanted in silicate material and combined with oxygen are considered crucial for forming OH/H<sub>2<sub/>O on the Moon and other airless bodies. This process may also have contributed to hydrogen delivery to planetary interiors through the accretion of micrometre-sized dust and planetesimals during early stages of the Solar System.<i>Aims<i/>. This paper experimentally investigates the depth distribution of solar wind protons in silicate materials and explores the mechanisms that influence this profile.<i>Methods<i/>. We simulated solar wind irradiation by implanting 3 keV D<sub>2<sub/><sup>+<sup/> ions in three typical silicates (olivine, pyroxene, and plagio-clase) at a fluence of ~1.4 × 10<sup>17<sup/> ions/cm<sup>2<sup/>. Fourier transform infrared spectroscopy was used to analyse chemical bond changes, while transmission electron microscopy (TEM) characterised microstructural modifications. Nanoscale secondary ion mass spectrometry (NanoSIMS) was employed to measure the D/<sup>16<sup/>O ratio and determine the depth distribution of implanted deuterium.<i>Results<i/>. The newly produced OD band (at 2400-2800 cm<sup>−1<sup/> ) in the infrared spectrum reveals the formation of O–D bonds in the irradiated silicates. The TEM and NanoSIMS results suggest that over 73% of the implanted D accumulated in fully amorphous rims with a depth of 70 nm, while 25% extended inwards to ~190 nanometres, resulting in partial amorphisation. The distribution of these deuterium particles is governed by the collision processes of the implanted particles, which involve factors such as initial energy loss, cascade collisions, and channelling effects. Furthermore, up to 2% of the total implanted D penetrated the intact lattice via diffusion, reaching depths ranging from hundreds of nanometres to several micrometres.<i>Conclusions<i/>. Our results suggest that implanted solar wind protons can be retained in silicate interiors, which may significantly affect the hydrogen isotopic composition in extraterrestrial samples and imply an important source of hydrogen during the formation of terrestrial planets.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"62 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670327","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":"Spectral reconstruction for radiation hydrodynamic simulations of galaxy evolution","authors":"Bernhard Baumschlager, Sijing Shen, James W. Wadsley","doi":"10.1051/0004-6361/202348164","DOIUrl":"https://doi.org/10.1051/0004-6361/202348164","url":null,"abstract":"Radiation from stars and active galactic nuclei (AGN) plays an important role in galaxy formation and evolution, and profoundly transforms the intergalactic, circumgalactic, and interstellar medium (IGM, CGM, and ISM). On-the-fly radiative transfer (RT) has started being incorporated in cosmological simulations, but the complex evolving radiation spectra are often crudely approximated with a small number of broad bands with piece-wise constant intensity and a fixed photo-ionisation cross-section. Such a treatment is unable to capture the changes to the spectrum as light is absorbed while it propagates through a medium with non-zero opacity. This can lead to large errors in photo-ionisation and heating rates. In this work we present a novel approach of discretising the radiation field at discrete photon energies, at the edges of the typically used photo-ionising bands, in order to capture the power-law slope of the radiation field. In combination with power-law approximations for the photo-ionisation cross-sections, this model allows us to self-consistently combine radiation from sources with different spectra and accurately follow the ionisation states of primordial and metal species through time. The method is implemented in GASOLINE2 in connection with TREVR2, a fast reverse ray tracing algorithm with 𝒪(<i>N<i/><sub>active<sub/> log<sub>2<sub/> <i>N<i/>) scaling. We compare our new piece-wise power-law reconstruction to the piece-wise constant method in calculating the primordial chemistry photo-ionisation and heating rates under an evolving UV background (UVB) and stellar spectrum, and find that our method reduces errors significantly, by up to two orders of magnitude in the case of HeII ionisation. We apply our new spectral reconstruction method in RT post-processing of a cosmological zoom-in simulation, MUGS2 g1536, including radiation from stars and a live UVB, and find a significant increase in total neutral hydrogen (HI) mass in the ISM and the CGM due to shielding of the UVB and a low escape fraction of the stellar radiation. This demonstrates the importance of RT and an accurate spectral approximation in simulating the CGM-galaxy ecosystem.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"10 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670265","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":"Nonthermal GeV emission from the Nereides nebula: Confirming the nature of the supernova remnant G107.7−5.1","authors":"Miguel Araya","doi":"10.1051/0004-6361/202451443","DOIUrl":"https://doi.org/10.1051/0004-6361/202451443","url":null,"abstract":"<i>Context.<i/> Recently, the Nereides nebula was discovered through deep optical emission line observations and was classified as a supernova remnant (SNR) candidate, G107.7−5.1.<i>Aims.<i/> Since very little is known about this SNR, we have looked at several archival datasets to better understand the environment and properties of the object.<i>Methods.<i/> We present a detailed analysis of the gamma-ray emission detected by the <i>Fermi<i/> Large Area Telescope in the region of the nebula. A model of the nonthermal emission is presented that allows us to derive the particle distribution responsible for the gamma rays. We also use molecular gas and atomic hydrogen observations to try to constrain the source age and distance.<i>Results.<i/> An extended (∼2°) GeV source coincident with the location of the nebula is found. The nonthermal emission has a hard spectrum and is detected up to ∼100 GeV, confirming the SNR nature of this object. The GeV properties of G107.7−5.1 are similar to those of other SNRs such as G150.3​ + ​4.5, and it likely expands in a relatively low-density medium. The Nereides nebula is one more example of a growing population of dim SNRs detected at high energies. A simple leptonic model is able to account for the gamma-ray emission. Standard SNR evolutionary models constrain the age to be in the 10 − 50 kyr range, which is consistent with estimates of the maximum particle energy obtained from GeV observations. However, more detailed observations of the source should be carried out to better understand its properties.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"10 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670331","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}