Experimental Astronomy最新文献

{"title":"Ground calibration result of the wide-field X-ray telescope (WXT) onboard the Einstein probe","authors":"Huaqing Cheng,&nbsp;Chen Zhang,&nbsp;Zhixing Ling,&nbsp;Xiaojin Sun,&nbsp;Shengli Sun,&nbsp;Yuan Liu,&nbsp;Yanfeng Dai,&nbsp;Zhenqing Jia,&nbsp;Haiwu Pan,&nbsp;Wenxin Wang,&nbsp;Donghua Zhao,&nbsp;Yifan Chen,&nbsp;Zhiwei Cheng,&nbsp;Wei Fu,&nbsp;Yixiao Han,&nbsp;Junfei Li,&nbsp;Zhengda Li,&nbsp;Xiaohao Ma,&nbsp;Yulong Xue,&nbsp;Ailiang Yan,&nbsp;Qiang Zhang,&nbsp;Yusa Wang,&nbsp;Xiongtao Yang,&nbsp;Zijian Zhao,&nbsp;Longhui Li,&nbsp;Ge Jin,&nbsp;Weimin Yuan","doi":"10.1007/s10686-025-10025-9","DOIUrl":"10.1007/s10686-025-10025-9","url":null,"abstract":"<div><p>We report on results of the on-ground X-ray calibration of the Wide-field X-ray Telescope (WXT), built from novel lobster-eye micro-pore optics, on board the <i>Einstein Probe (EP)</i> satellite. To fully characterize the performance and properties of the WXT instrument, a series of tests and calibrations were conducted at different levels of devices, assemblies and the complete module before the launch of <i>EP</i>. In this paper, we present the calibration results of three flight model modules (FM1, FM5 and FM11) obtained during their end-to-end module calibration experiments carried out at the 100-m X-ray Test Facility (100XF) of the Institute of High Energy Physics (IHEP), Chinese Academy of Sciences (CAS). Measurements of the Point Spread Function (PSF), effective area, and energy response were performed for multiple incident directions and several characteristic X-ray emission line energies. Specifically, the distributions of the PSF and effective areas are found to be roughly uniform across the FoV, in large agreement with the prediction of lobster-eye optics. Their energy-dependent behavior aligns well with theoretical predictions and Monte Carlo simulations. At <span>(sim 1.25)</span> keV, the full width at half maximum (FWHM) of the focal spot ranges from <span>(3-7)</span> arcmin (with a median of <span>(sim 4.2)</span> arcmin) and the effective area is in range of <span>(sim 2-3~mathrm{cm^2})</span>. Noticeably, the flight model instruments demonstrate a <span>(sim 1.5)</span> arcmin improvement in spatial resolution over the previously launched Lobster Eye Imager for Astronomy. The properties of the complementary metal-oxide semiconductor (CMOS) sensors were also calibrated. The gain coefficients are in range of <span>(6.4-6.9~mathrm{eV/DN})</span>. The energy resolutions are in range of <span>(sim 120)</span> to 140 eV at 1.25 keV, meeting design requirements. These calibration results have been ingested into the first version of calibration database (CALDB) and applied to the analysis of the scientific data acquired by WXT after the launch of <i>EP</i>.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"60 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-025-10025-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145210466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Performance study of swept charge device array in orbit","authors":"Wei Li,&nbsp;Laidan Luo,&nbsp;Yanji Yang,&nbsp;Xiaofan Zhao,&nbsp;Xiaobo Li,&nbsp;Weiwei Cui,&nbsp;Yupeng Xu,&nbsp;Yong Chen","doi":"10.1007/s10686-025-10030-y","DOIUrl":"10.1007/s10686-025-10030-y","url":null,"abstract":"<div><p>The Low Energy X-ray Telescope (LE) is one of the three scientific instruments onboard the Insight-Hard X-ray Modulation Telescope (Insight-HXMT). Its primary scientific objectives include conducting both scanning and pointed observations within the soft X-ray band, specifically from 0.7 keV to 13 keV. The LE utilizes a Swept Charge Device (SCD) and forms a large-area array, achieving good energy resolution and time resolution. Due to exposure to space radiation, the performance of the detector gradually declines. By analyzing almost 7 years of LE onboard data, we studied the changes in detector performance and their underlying causes, including aspects such as readout noise, energy resolution, detector gain, and the proportion of split events. The results indicate that the readout noise increases continuously over time; the noise peak position drifts gradually; the energy resolution degrades at a rate of 50–60 eV per year, primarily due to the increasing charge transfer inefficiency; the detector gain decreases by approximately 0.8–1.3% each year; and the variation in the proportion of split events is only related to the detector threshold and is independent of space radiation. These studies provide important references for determining the LE observation plan and for analyzing the performance evolution of similar semiconductor detectors.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"60 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145170683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Design and analysis of simulator for eastern anatolia observatory (DAG) telescope","authors":"Kemal Rüzgar,&nbsp;Derya Öztürk Çetni,&nbsp;Cahit Yeşilyaprak,&nbsp;Burak Bülent Güçsav","doi":"10.1007/s10686-025-10026-8","DOIUrl":"10.1007/s10686-025-10026-8","url":null,"abstract":"<div><p>Telescope simulators may initially seem essential only for space telescopes, but they also have a significant impact on the development and operational processes of ground-based telescope instruments. Besides, the simulators for ground-based observatory telescopes are also functional as laboratory testing instruments for the development of new instruments or the evaluation of specific instruments. Considering this aspect, we present the design of an optical simulator as an on-off optical system for the Eastern Anatolia Observatory (DAG) Telescope with 4m diameter. We have planned to install this simulator on the Nasmyth platform of the DAG Telescope to be used as a maintenance, calibration and test assembly during non-observing periods because of the atmospheric conditions of the site of Eastern Anatolia Observatory (DAG; Doğu Anadolu Gözlemevi in Turkish). The simulator designed for the DAG Telescope will provide great convenience in completing the testing and calibration processes easily, and also saving time and manpower. In the production phase for the simulator, we plan to produce twin systems, one on the Nasmyth platform and the other in a laboratory. In this context, it will serve both design and test process in an optical laboratory environment and also in the real environment testing process of new optical systems on the Nasymth platform of the DAG Telescope located in the DAG site (Karakaya Hill, 3170 m altitude, Erzurum) of the Türkiye National Observatories.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"60 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Digital micromirror device characterization in optical band for astronomical multi-object spectrograph","authors":"Sriram S,&nbsp;Vineeth Valsan,&nbsp;Remya B.S,&nbsp;Subramaniam A,&nbsp;Maheswar G","doi":"10.1007/s10686-025-10023-x","DOIUrl":"10.1007/s10686-025-10023-x","url":null,"abstract":"<div><p>The Digital Micromirror Device (DMD), a micro-electro-mechanical system (MEMS) consisting of individually controllable micromirrors, has emerged as a versatile tool for astronomical instrumentation, particularly in multi-object spectroscopy (MOS). Unlike traditional slit masks or fiber-based systems, DMDs offer dynamic reconfigurability, enabling efficient light modulation and enhanced spectral acquisition. Their adaptability has led to widespread adoption in ground-based spectrographs (e.g., RITMOS, BATMAN, SAMOS, IRMOS) and feasibility studies for space missions (e.g., EUCLID, CASTOR, SUMO, SIRMOS). DMDs have demonstrated robustness in space qualification tests, including radiation exposure, thermal cycling, and mechanical stress, making them viable for space-based applications. Recent advancements, such as UV-transparent windows and enhanced coatings, further expand their potential for ultraviolet astronomy. In India, the success of AstroSat’s Ultra Violet Imaging Telescope (UVIT) has motivated the development of the next-generation INdian Spectroscopic and Imaging Space Telescope (INSIST), which includes a DMD-based MOS for UV/optical observations. To advance its Technology Readiness Level (TRL), we evaluated the Texas Instruments DLP9500 DMD (1920 <span>(times)</span> 1080 micromirrors, 10 <span>(upmu)</span>m pitch) in the optical band, assessing key parameters such as diffraction efficiency, reflectivity, contrast, micromirror repeatability, and Point Spread Function (PSF) alignment. This study establishes a foundation for future UV-optimized DMD applications in INSIST and other astronomical missions.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"60 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144934634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"An mTSP model for multiple telescope short-term scheduling","authors":"Chaoran Han,&nbsp;John Cater,&nbsp;Oliver Sinnen","doi":"10.1007/s10686-025-10022-y","DOIUrl":"10.1007/s10686-025-10022-y","url":null,"abstract":"<div><p>Pulsar observation scheduling is a highly dynamic problem with uncertainty caused by scintillation and environmental interference. In the scheduling systems used by observatories today, this uncertainty is usually accounted for by using a short-term scheduling process. In order to observe as many pulsars as possible within a certain period of time, it becomes imperative for multiple telescopes or sub-arrays to observe multiple targets at the same time. However, there is little research on the speed improvement and cost-efficiency improvement of such “parallel\" observation with multiple telescopes. In this work, we have designed a multiple telescope short-term scheduling simulation system, based on extending previously proposed scheduling heuristics using a single telescope pulsar scheduling simulator. Additionally, we propose a more complex multiple telescope short-term scheduling policy based on the multiple travelling salesperson problem (mTSP). Realistic datasets within the simulation environment are used to evaluate the proposed algorithms with multiple telescopes. The results show that multiple telescopes can significantly reduce the time to observe a set of pulsars. The previous single telescope heuristics adapt surprisingly well to the multiple telescope scenario and the novel mTSP policy is competitive, with potential for future improvements.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"60 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144927031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Improving radial velocity precision with CARMENES-PLUS","authors":"R. Varas,&nbsp;R. Calvo-Ortega,&nbsp;P. J. Amado,&nbsp;S. Becerril,&nbsp;H. Ruh,&nbsp;M. Azzaro,&nbsp;L. Hernández,&nbsp;H. Magán-Madinabeitia,&nbsp;S. Reinhart,&nbsp;D. Maroto-Fernández,&nbsp;J. Helmling,&nbsp;Á. L. Huelmo,&nbsp;D. Benítez,&nbsp;J. F. López,&nbsp;M. Pineda,&nbsp;J. A. García,&nbsp;J. García de la Fuente,&nbsp;J. Marín,&nbsp;F. Hernández,&nbsp;J. Aceituno,&nbsp;J. A. Caballero,&nbsp;A. Kaminski,&nbsp;R. J. Mathar,&nbsp;A. Quirrenbach,&nbsp;A. Reiners,&nbsp;I. Ribas,&nbsp;W. Seifert,&nbsp;M. Zechmeister","doi":"10.1007/s10686-025-10020-0","DOIUrl":"10.1007/s10686-025-10020-0","url":null,"abstract":"<div><p><b>Context:</b> CARMENES is a dual-channel high-resolution spectrograph at the 3.5 m Calar Alto telescope designed to detect low-mass planets around late-type dwarfs by measuring their radial velocities (RVs). High thermal stability in both the visible (VIS) and near-infrared (NIR) channels is essential to achieve the precision required for these measurements. In particular, stabilising the NIR channel to the millikelvin level, which operates at cryogenic temperatures ( <span>(sim)</span> 140 K), poses significant engineering challenges. <b>Purpose:</b> The CARMENES-PLUS project was initiated to improve the instrument’s intrinsic RV precision. In this article, we focus on the thermal stability improvements made to the NIR channel’s cooling system. <b>Methods:</b> The NIR cooling system was originally conceived to operate with a discontinuous flow of cryogenic nitrogen gas. As part of CARMENES-PLUS, this was upgraded to a continuous flow configuration. Additional changes included the installation of an automatic vacuum system, a proportional control valve, and a pressure regulation system. These upgrades were designed to reduce thermal fluctuations and enhance long-term stability. <b>Results:</b> The implemented upgrades significantly improved the intrinsic RV precision of the NIR channel. We quantified this improvement using Fabry-Pérot calibration spectra, obtaining an intrinsic RV precision of 0.67 m s<span>(^{-1})</span> after the interventions, an improvement of nearly 2 m s<span>(^{-1})</span>. We also assessed the stability of the nightly zero points, finding a reduced scatter of 3.9 m s<span>(^{-1})</span> post-upgrade, compared to 6.1 m s<span>(^{-1})</span> before. For a sample of slowly rotating stars (<span>(v sin i_star le)</span> 2 km s<span>(^{-1})</span>), the median scatter decreased from 8.8 m s<span>(^{-1})</span> to 6.7 m s<span>(^{-1})</span> after the upgrades. <b>Conclusions</b>: These results demonstrate that the thermal control upgrades introduced in CARMENES-PLUS have enhanced the NIR channel’s RV performance, bringing it closer to the VIS channel’s stability and reinforcing CARMENES’s capabilities for exoplanet detection around M dwarfs.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"60 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-025-10020-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144923127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Benchmarking of Geant4 simulations for the COSI Anticoincidence System","authors":"Alex Ciabattoni,&nbsp;Valentina Fioretti,&nbsp;John A. Tomsick,&nbsp;Andreas Zoglauer,&nbsp;Parshad Patel,&nbsp;Lee Mitchell,&nbsp;Andrea Bulgarelli,&nbsp;Pierre Jean,&nbsp;Gabriele Panebianco,&nbsp;Nicolò Parmiggiani,&nbsp;Cristian Vignali,&nbsp;Peter von Ballmoos,&nbsp;Eric Wulf","doi":"10.1007/s10686-025-10019-7","DOIUrl":"10.1007/s10686-025-10019-7","url":null,"abstract":"<div><p>The Compton Spectrometer and Imager (COSI) is an upcoming NASA Small Explorer satellite mission, designed for all-sky observations in the soft gamma-ray domain with the use of germanium detectors (GeDs). An active Anticoincidence System (ACS) of BGO scintillators surrounds the GeDs to reduce the background and contribute to the detection of transient events. Accurately modeling the ACS performance requires simulating the intricate scintillation processes within the shields, which significantly increases the computational cost. We have encoded these effects into a correction matrix derived from dedicated Geant4 simulations with the inclusion of the optical physics. For this purpose, we use laboratory measurements for the energy and spatial response of the ACS lateral wall to benchmark the simulation and define instrument parameters, including the BGO absorption length and the electronic noise. We demonstrate that the simulations replicate the experimental energy resolution and light collection uniformity along the BGO crystal, with maximum discrepancies of 20% and 10%, respectively. The validated simulations are then used to develop the correction matrix for the lateral wall, accounting for the light collection efficiency and energy resolution based on the position within the crystal. The gamma-ray quantum detection efficiency is also position-dependent via the inclusion of the optical physics. It is enhanced by <span>(sim)</span>8% close to the SiPMs and suppressed by <span>(sim)</span>2% in the adjacent corners with respect to the average value. Finally, we explore the energy threshold and resolution of the bottom ACS, considering the impact of its smaller crystals compared with the lateral walls.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"60 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-025-10019-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145142118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Remote health monitoring system for the Chiang Mai 13-m VGOS radio telescope","authors":"Wei-Hua Shang-Guan,&nbsp;Rong-Bing Zhao,&nbsp;Jin-Qing Wang,&nbsp;Jin-Ling Li,&nbsp;Qing-Hui Liu,&nbsp;Shao-Guang Guo,&nbsp;Yong-Bin Jiang,&nbsp;Zhen Yan,&nbsp;Fan-Duo Ba-Sang,&nbsp;Heng Dai,&nbsp;Yi-Xin Wang","doi":"10.1007/s10686-025-10012-0","DOIUrl":"10.1007/s10686-025-10012-0","url":null,"abstract":"<div><p>The VGOS 13m radio telescope located in Chiang Mai, Thailand is the first VGOS standard station built overseas by China. This station expands Chinese very long baseline interferometry (VLBI) network (CVN) and furthers multiple scientific goals, such as continuous monitoring of Earth orientation parameters and research into the terrestrial and celestial reference frames. The station is equipped with a wideband 2-14GHz receiver and an X/Ka dual-frequency receiver, a fast-slewing antenna, a DBBC3 high-speed data acquisition terminal and a high-speed recording terminal. This is aimed at improving observation efficiency and research quality. We developed the Remote Health Monitoring System (RHMS) specifically for the VGOS 13m radio telescope located in Thailand. This system integrates Tango Controls’ distributed middleware technology, allowing it to furnish the observation team with comprehensive historical and real-time status updates for the Chiang Mai VGOS station. Additionally, it promptly issues alerts for abnormalities, thereby improving the station’s unmanned monitoring, maintenance and operations capabilities, and operational performance. It also provides a feasible solution for remote monitoring of future overseas VGOS stations.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"60 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145143883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Near infra-red absorption spectroscopy for astrophysically significant ions","authors":"Kirsten Dowd,&nbsp;Eric Doyle,&nbsp;Padraig Dunne","doi":"10.1007/s10686-025-10009-9","DOIUrl":"10.1007/s10686-025-10009-9","url":null,"abstract":"<div><p>We present a novel laboratory astrophysics experiment to obtain photoabsorption spectra of neutral and near neutral atomic species in the near infrared (NIR) spectral region. A laser produced plasma containing the ions of interest is probed by the collimated output of a supercontinuum fiber laser. The resulting absorption spectrum is recorded on a 0.75-m spectrograph equipped with a complimentary metal oxide semiconductor (CMOS) camera. Spectra of yttrium plasmas were recorded 11 <span>(upmu )</span>s after its formation in the range from 700 to 1100 nm, and we present the spectrum between 708 to 832 nm to illustrate the capabilities of the technique. In this range we found 26 lines previously identified and 29 lines not previously identified. The importance of new atomic structure data, in particular transition energies and relative oscillator strengths, is highlighted in the context of increasingly sophisticated ground and space-based spectrometers in the era of multi-messenger astronomy. Future developments and improvements are briefly discussed.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"60 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12271273/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144673674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"XMM-Newton follow-up of two eROSITA X-ray binary candidates","authors":"A. Avakyan,&nbsp;A. Zainab,&nbsp;V. Doroshenko,&nbsp;J. Wilms,&nbsp;A. Schwope,&nbsp;V. Suleimanov,&nbsp;D. Buckley,&nbsp;J. Brink,&nbsp;A. Santangelo","doi":"10.1007/s10686-025-10016-w","DOIUrl":"10.1007/s10686-025-10016-w","url":null,"abstract":"<div><p>We report on the follow-up observations with XMM-<i>Newton</i> of two X-ray binary candidates identified in the first eROSITA all-sky survey data (eRASS1), 1eRASS J061330.8<span>(+)</span>160440 and 1eRASS J161201.9−464622. Based on the obtained results, in particular, the observed X-ray spectra and lack of pulsations, as well as properties of the identified optical counterparts, we conclude that both candidates are unlikely to be XRBs. Based on LAMOST optical spectroscopy and SED fit results for 1eRASS J061330.8<span>(+)</span>160440 we classify it as an M0 chromospherically active subgiant star. ZTF and TESS photometry reveal highly significant period for this object of 7.189 days, which likely attributed to starspot(s). On the other hand, SALT follow-up spectroscopy of 1eRASS J161201.9−464622 solidly classifies this source as a bright novalike cataclysmic variable (CV), the second discovered with eROSITA. A persistent 4.802 h signal is found across all three available TESS observations, and is tentatively identified as the orbital period of the binary. Follow-up high-speed photometry and time-resolved spectroscopy are required to confirm the derived orbital modulation.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"60 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-025-10016-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145142984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}