Astronomische Nachrichten最新文献

Issue Information: Astron. Nachr. 1/2025

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2025-02-02 DOI: 10.1002/asna.20259001

引用次数: 0

Cover Picture: Astron. Nachr. 1/2025

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2025-02-02 DOI: 10.1002/asna.20259010

S. Friedrich, C. Maitra, K. Dennerl, A. Schwope, K. Werner, B. Stelzer

{"title":"Cover Picture: Astron. Nachr. 1/2025","authors":"S. Friedrich, C. Maitra, K. Dennerl, A. Schwope, K. Werner, B. Stelzer","doi":"10.1002/asna.20259010","DOIUrl":"https://doi.org/10.1002/asna.20259010","url":null,"abstract":"Hunting for white dwarfs in eROSITA surveys 1-4 with special processing. The Gaia color-magnitude diagram shows all white dwarf candidates from the Gaia white dwarf catalogue (Gentile Fusillo et al. 2021), colour-coded with the probability of being a white dwarf. Black circles mark sources in the ROSAT white dwarf catalogue (Fleming et al. 1996) that match entries in the Gaia white dwarf catalogue (light blue crosses indicate those in the German half of the eROSITA sky). Orange crosses mark eROSITA sources with a hardness ratio of ≤ −0.94 and with counterparts in the Gaia white dwarf catalogue. Those highlighted with a dark green circle have a probability larger than 90 % of being a white dwarf in that catalogue. The cooling tracks of white dwarfs with masses between 0.4 and 1.2 solar masses are shown as gray lines in steps of 0.1 solar masses (top to bottom). For more details see the related paper by S. Friedrich et al. published in this issue e240139.\u0000\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture>\u0000 </div>\u0000 </figure>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asna.20259010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143110434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modeling the Emission and Polarization Properties of Pulsating Ultraluminous X-Ray Sources

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2025-01-26 DOI: 10.1002/asna.20240129

S. Conforti, L. Zampieri, R. Taverna, R. Turolla, N. Brice, F. Pintore, G. L. Israel

{"title":"Modeling the Emission and Polarization Properties of Pulsating Ultraluminous X-Ray Sources","authors":"S. Conforti, L. Zampieri, R. Taverna, R. Turolla, N. Brice, F. Pintore, G. L. Israel","doi":"10.1002/asna.20240129","DOIUrl":"https://doi.org/10.1002/asna.20240129","url":null,"abstract":"Pulsating Ultraluminous X-ray Sources (PULXs) are a class of extragalactic sources with high X-ray luminosity, in excess of <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mn>10</mn>\u0000 <mn>39</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ {10}^{39} $$</annotation>\u0000 </semantics></math> erg <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mi>s</mi>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ {mathrm{s}}^{-1} $$</annotation>\u0000 </semantics></math>, and showing pulsations that associate them with neutron stars accreting at a super-Eddington rate. A simplified model is presented, which describes the thermal emission from an accreting, highly magnetized neutron star and includes the contributions from an accretion disk and an accretion envelope surrounding the star magnetosphere. Through numerical calculations, we determine the flux, pulsed fractions, polarization degree, and polarization angle considering various viewing geometries. The model is confronted with the XMM-Newton spectra of M51 ULX-7, and the best fitting viewing geometries are estimated. A measurement of the polarization observables, which will be available with future facilities, along with spectroscopic data obtained with XMM-Newton, will provide considerable additional information on these sources.","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asna.20240129","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143119540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Meaning of Quasi-Simultaneous X-Rays and Gamma-Ray Observations of RS Oph in Outburst

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2025-01-13 DOI: 10.1002/asna.20240140

Marina Orio, Ke Fang, Jay Gallagher, Gerardo Juan M. Luna, Joanna Mikolajewska

{"title":"The Meaning of Quasi-Simultaneous X-Rays and Gamma-Ray Observations of RS Oph in Outburst","authors":"Marina Orio, Ke Fang, Jay Gallagher, Gerardo Juan M. Luna, Joanna Mikolajewska","doi":"10.1002/asna.20240140","DOIUrl":"https://doi.org/10.1002/asna.20240140","url":null,"abstract":"Shocks in novae outbursts are ubiquitous, but in symbiotic novae, they are particularly powerful, probably because of the surrounding red giant wind. The recurrent nova RS Oph is the best example of this phenomenon. The presence of shocked plasma in outburst was inferred from optical spectra, and it was confirmed by X-ray observations since 1985. Since 2010, the gamma-ray observatory Fermi has proven that novae in general are the site of particle acceleration, producing copious gamma-ray flux in the few-GeV range. In the last outburst of the symbiotic RS Oph in 2021, gamma-rays were not only detected with Fermi in the GeV range but also detected in the TeV range of the Cherenkov telescopes, for about 3 weeks. Diesing et al. in 2023 showed that there must have been at least two distinct episodes of shocks, likely of hadronic nature, both generating particle acceleration. We present new NuSTAR data and re-discuss XMM-Newton high-resolution grating spectra and NICER data that we recently published. We concluded that the primary shock causing the particle acceleration observed in the range of TeV gamma-rays with the Cherenkov telescopes was the same phenomenon observed and studied with the x-ray observatories. However, the shocked plasma from which the particles were accelerated causing the gamma-ray flux observed after 1 day with Fermi was—at least initially—unobservable. We suggest that this first episode of shock occurred when the nova ejecta collided with a dense outflow close to the atmosphere of the red giant, with such a high absorbing column that x-rays were absorbed.","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asna.20240140","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143114534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Issue Information: Astron. Nachr. 09/2024 发行信息：Astron.Nachr.09/2024

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2025-01-12 DOI: 10.1002/asna.20249008

引用次数: 0

Cover Picture: Astron. Nachr. 9/2024

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2025-01-12 DOI: 10.1002/asna.20249017

Balázs Pál, László Dobos

引用次数: 0

Searching the Non-Accreting White Dwarf Population in eROSITA Data

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2025-01-08 DOI: 10.1002/asna.20240139

S. Friedrich, C. Maitra, K. Dennerl, A. Schwope, K. Werner, B. Stelzer

引用次数: 0

Letter From the Editor

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2025-01-06 DOI: 10.1002/asna.20240141

Klaus G. Strassmeier

{"title":"Letter From the Editor","authors":"Klaus G. Strassmeier","doi":"10.1002/asna.20240141","DOIUrl":"https://doi.org/10.1002/asna.20240141","url":null,"abstract":"With the present first issue of volume 346 in 2025, we enter the 204th year of continuous appearance of Astronomische Nachrichten/Astronomical Notes (AN). The continuing complexity of worldwide scientific publishing had kept us busy over the years; it also impacts AN. The tricky part for our comparably small journal is maintaining a high standard, but also being openly accessible at the same time, preferably without costs. The end product shall be a peer-reviewed, content-oriented, and thus user-oriented, widely distributed and easily accessible journal with original research papers that one is happy to cite.This is achieved with accompanying editorial changes. While we currently still rely on the ScholarOne submission platform for user interaction, it will be replaced with the new editorial system Research Exchange (ReX) that is being rolled out as a peer-review tool to all Wiley journals during the course of this year. eLocators instead of the sequential page numbers for easy identification, a modern web appearance where you can find the latest but also all historical volumes of AN, and open access as part of the European DEAL treaty remain cornerstones. AN's most recent Journal Impact Factor (Clarivate) is 1.1.As before, the Leibniz-Institute for Astrophysics Potsdam (AIP) continues hosting the editorial office in close collaboration with Wiley. The editorial team can be contacted through [email protected]. Papers are welcomed in all fields of astronomy, astrophysics, and solar-system research, as well as related aspects in instrumentation, astrobiologic, and historic studies. Many thanks in advance. We are looking forward to another year of submissions.The author declares no conflicts of interest.","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asna.20240141","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143112296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Carl Wirtz' Article From 1924 in Astronomische Nachrichten on the Radial Motions of Spiral Nebulae 卡尔-维茨（Carl Wirtz）1924 年在《天文学通讯》上发表的关于螺旋星云径向运动的文章

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2024-12-23 DOI: 10.1002/asna.20240062

Tom Richtler

引用次数: 0

The Surprising Long-Term Evolution of the ULXP NGC 7793 P13

IF 1.1 4区物理与天体物理

Astronomische Nachrichten Pub Date : 2024-12-22 DOI: 10.1002/asna.20240106

Felix Fürst, Dominic J. Walton, Matteo Bachetti, Hannah Earnshaw, Murray Brightman

{"title":"The Surprising Long-Term Evolution of the ULXP NGC 7793 P13","authors":"Felix Fürst, Dominic J. Walton, Matteo Bachetti, Hannah Earnshaw, Murray Brightman","doi":"10.1002/asna.20240106","DOIUrl":"https://doi.org/10.1002/asna.20240106","url":null,"abstract":"<div>\u0000 \u0000 The ultra-luminous x-ray pulsar (ULXP) NGC 7793 P13 has been regularly monitored with XMM-Newton, NuSTAR, and Swift for the last 8 years. Here, we present the latest results of this monitoring campaign with respect to the pulse period evolution and spectral variability. We find that since the source recovered from an x-ray low state in 2020–2022 the spin-up rate has increased significantly compared with before the off-state, even though the x-ray luminosity has not shown an equivalent increase. We find that the x-ray and optical/UV flux are anti-correlated, and speculate that this variability might be driven by a large accretion disk, precessing at a super-orbital period of 7–8 years. We study the spectral behavior in the XMM-Newton and NuSTAR data, and find very little changes in the spectral shape, despite the large flux variability. This spectral consistency provides further indication that the observed flux variability is a geometric effect and not due to intrinsic changes of the accretion rate.\u0000 </div>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"346 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143117877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0