[{"related_material":{"link":[{"relation":"erratum","url":"https://doi.org/10.1051/0004-6361/201935684e"}]},"oa":1,"_id":"13470","quality_controlled":"1","doi":"10.1051/0004-6361/201935684","article_number":"A151","author":[{"last_name":"Shenar","first_name":"T.","full_name":"Shenar, T."},{"first_name":"D. P.","full_name":"Sablowski, D. P.","last_name":"Sablowski"},{"first_name":"R.","full_name":"Hainich, R.","last_name":"Hainich"},{"last_name":"Todt","first_name":"H.","full_name":"Todt, H."},{"last_name":"Moffat","first_name":"A. F. J.","full_name":"Moffat, A. F. J."},{"full_name":"Oskinova, L. M.","first_name":"L. M.","last_name":"Oskinova"},{"full_name":"Ramachandran, V.","first_name":"V.","last_name":"Ramachandran"},{"last_name":"Sana","full_name":"Sana, H.","first_name":"H."},{"full_name":"Sander, A. A. C.","first_name":"A. A. C.","last_name":"Sander"},{"last_name":"Schnurr","full_name":"Schnurr, O.","first_name":"O."},{"last_name":"St-Louis","full_name":"St-Louis, N.","first_name":"N."},{"full_name":"Vanbeveren, D.","first_name":"D.","last_name":"Vanbeveren"},{"first_name":"Ylva Louise Linsdotter","full_name":"Götberg, Ylva Louise Linsdotter","orcid":"0000-0002-6960-6911","last_name":"Götberg","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d"},{"last_name":"Hamann","first_name":"W.-R.","full_name":"Hamann, W.-R."}],"type":"journal_article","volume":627,"month":"07","publication_status":"published","keyword":["Space and Planetary Science","Astronomy and Astrophysics"],"oa_version":"Published Version","article_type":"original","scopus_import":"1","article_processing_charge":"No","date_updated":"2023-08-09T12:29:58Z","publication_identifier":{"issn":["0004-6361"],"eissn":["1432-0746"]},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","citation":{"chicago":"Shenar, T., D. P. Sablowski, R. Hainich, H. Todt, A. F. J. Moffat, L. M. Oskinova, V. Ramachandran, et al. “The Wolf–Rayet Binaries of the Nitrogen Sequence in the Large Magellanic Cloud.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2019. <a href=\"https://doi.org/10.1051/0004-6361/201935684\">https://doi.org/10.1051/0004-6361/201935684</a>.","short":"T. Shenar, D.P. Sablowski, R. Hainich, H. Todt, A.F.J. Moffat, L.M. Oskinova, V. Ramachandran, H. Sana, A.A.C. Sander, O. Schnurr, N. St-Louis, D. Vanbeveren, Y.L.L. Götberg, W.-R. Hamann, Astronomy &#38; Astrophysics 627 (2019).","mla":"Shenar, T., et al. “The Wolf–Rayet Binaries of the Nitrogen Sequence in the Large Magellanic Cloud.” <i>Astronomy &#38; Astrophysics</i>, vol. 627, A151, EDP Sciences, 2019, doi:<a href=\"https://doi.org/10.1051/0004-6361/201935684\">10.1051/0004-6361/201935684</a>.","ieee":"T. Shenar <i>et al.</i>, “The Wolf–Rayet binaries of the nitrogen sequence in the Large Magellanic Cloud,” <i>Astronomy &#38; Astrophysics</i>, vol. 627. EDP Sciences, 2019.","ama":"Shenar T, Sablowski DP, Hainich R, et al. The Wolf–Rayet binaries of the nitrogen sequence in the Large Magellanic Cloud. <i>Astronomy &#38; Astrophysics</i>. 2019;627. doi:<a href=\"https://doi.org/10.1051/0004-6361/201935684\">10.1051/0004-6361/201935684</a>","apa":"Shenar, T., Sablowski, D. P., Hainich, R., Todt, H., Moffat, A. F. J., Oskinova, L. M., … Hamann, W.-R. (2019). The Wolf–Rayet binaries of the nitrogen sequence in the Large Magellanic Cloud. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/201935684\">https://doi.org/10.1051/0004-6361/201935684</a>","ista":"Shenar T, Sablowski DP, Hainich R, Todt H, Moffat AFJ, Oskinova LM, Ramachandran V, Sana H, Sander AAC, Schnurr O, St-Louis N, Vanbeveren D, Götberg YLL, Hamann W-R. 2019. The Wolf–Rayet binaries of the nitrogen sequence in the Large Magellanic Cloud. Astronomy &#38; Astrophysics. 627, A151."},"publisher":"EDP Sciences","year":"2019","status":"public","abstract":[{"text":"Context. Massive Wolf–Rayet (WR) stars dominate the radiative and mechanical energy budget of galaxies and probe a critical phase in the evolution of massive stars prior to core collapse. It is not known whether core He-burning WR stars (classical WR; cWR) form predominantly through wind stripping (w-WR) or binary stripping (b-WR). Whereas spectroscopy of WR binaries has so-far largely been avoided because of its complexity, our study focuses on the 44 WR binaries and binary candidates of the Large Magellanic Cloud (LMC; metallicity Z ≈ 0.5 Z⊙), which were identified on the basis of radial velocity variations, composite spectra, or high X-ray luminosities.\r\n\r\nAims. Relying on a diverse spectroscopic database, we aim to derive the physical and orbital parameters of our targets, confronting evolution models of evolved massive stars at subsolar metallicity and constraining the impact of binary interaction in forming these stars.\r\n\r\nMethods. Spectroscopy was performed using the Potsdam Wolf–Rayet (PoWR) code and cross-correlation techniques. Disentanglement was performed using the code Spectangular or the shift-and-add algorithm. Evolutionary status was interpreted using the Binary Population and Spectral Synthesis (BPASS) code, exploring binary interaction and chemically homogeneous evolution.\r\n\r\nResults. Among our sample, 28/44 objects show composite spectra and are analyzed as such. An additional five targets show periodically moving WR primaries but no detected companions (SB1); two (BAT99 99 and 112) are potential WR + compact-object candidates owing to their high X-ray luminosities. We cannot confirm the binary nature of the remaining 11 candidates. About two-thirds of the WN components in binaries are identified as cWR, and one-third as hydrogen-burning WR stars. We establish metallicity-dependent mass-loss recipes, which broadly agree with those recently derived for single WN stars, and in which so-called WN3/O3 stars are clear outliers. We estimate that 45  ±  30% of the cWR stars in our sample have interacted with a companion via mass transfer. However, only ≈12  ±  7% of the cWR stars in our sample naively appear to have formed purely owing to stripping via a companion (12% b-WR). Assuming that apparently single WR stars truly formed as single stars, this comprises ≈4% of the whole LMC WN population, which is about ten times less than expected. No obvious differences in the properties of single and binary WN stars, whose luminosities extend down to log L ≈ 5.2 [L⊙], are apparent. With the exception of a few systems (BAT99 19, 49, and 103), the equatorial rotational velocities of the OB-type companions are moderate (veq ≲ 250 km s−1) and challenge standard formalisms of angular-momentum accretion. For most objects, chemically homogeneous evolution can be rejected for the secondary, but not for the WR progenitor.\r\n\r\nConclusions. No obvious dichotomy in the locations of apparently single and binary WN stars on the Hertzsprung-Russell diagram is apparent. According to commonly used stellar evolution models (BPASS, Geneva), most apparently single WN stars could not have formed as single stars, implying that they were stripped by an undetected companion. Otherwise, it must follow that pre-WR mass-loss/mixing (e.g., during the red supergiant phase) are strongly underestimated in standard stellar evolution models.","lang":"eng"}],"main_file_link":[{"url":"https://doi.org/10.1051/0004-6361/201935684","open_access":"1"}],"date_created":"2023-08-03T10:14:09Z","date_published":"2019-07-16T00:00:00Z","publication":"Astronomy & Astrophysics","day":"16","extern":"1","language":[{"iso":"eng"}],"title":"The Wolf–Rayet binaries of the nitrogen sequence in the Large Magellanic Cloud","intvolume":"       627"},{"citation":{"mla":"Renzo, M., et al. “Massive Runaway and Walkaway Stars.” <i>Astronomy &#38; Astrophysics</i>, vol. 624, A66, EDP Sciences, 2019, doi:<a href=\"https://doi.org/10.1051/0004-6361/201833297\">10.1051/0004-6361/201833297</a>.","chicago":"Renzo, M., E. Zapartas, S. E. de Mink, Ylva Louise Linsdotter Götberg, S. Justham, R. J. Farmer, R. G. Izzard, S. Toonen, and H. Sana. “Massive Runaway and Walkaway Stars.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2019. <a href=\"https://doi.org/10.1051/0004-6361/201833297\">https://doi.org/10.1051/0004-6361/201833297</a>.","short":"M. Renzo, E. Zapartas, S.E. de Mink, Y.L.L. Götberg, S. Justham, R.J. Farmer, R.G. Izzard, S. Toonen, H. Sana, Astronomy &#38; Astrophysics 624 (2019).","ista":"Renzo M, Zapartas E, de Mink SE, Götberg YLL, Justham S, Farmer RJ, Izzard RG, Toonen S, Sana H. 2019. Massive runaway and walkaway stars. Astronomy &#38; Astrophysics. 624, A66.","apa":"Renzo, M., Zapartas, E., de Mink, S. E., Götberg, Y. L. L., Justham, S., Farmer, R. J., … Sana, H. (2019). Massive runaway and walkaway stars. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/201833297\">https://doi.org/10.1051/0004-6361/201833297</a>","ieee":"M. Renzo <i>et al.</i>, “Massive runaway and walkaway stars,” <i>Astronomy &#38; Astrophysics</i>, vol. 624. EDP Sciences, 2019.","ama":"Renzo M, Zapartas E, de Mink SE, et al. Massive runaway and walkaway stars. <i>Astronomy &#38; Astrophysics</i>. 2019;624. doi:<a href=\"https://doi.org/10.1051/0004-6361/201833297\">10.1051/0004-6361/201833297</a>"},"publisher":"EDP Sciences","year":"2019","external_id":{"arxiv":["1804.09164"]},"status":"public","scopus_import":"1","article_type":"original","article_processing_charge":"No","date_updated":"2023-08-09T12:26:08Z","publication_identifier":{"issn":["0004-6361"],"eissn":["1432-0746"]},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","extern":"1","language":[{"iso":"eng"}],"title":"Massive runaway and walkaway stars","intvolume":"       624","abstract":[{"lang":"eng","text":"We perform an extensive numerical study of the evolution of massive binary systems to predict the peculiar velocities that stars obtain when their companion collapses and disrupts the system. Our aim is to (i) identify which predictions are robust against model uncertainties and assess their implications, (ii) investigate which physical processes leave a clear imprint and may therefore be constrained observationally, and (iii) provide a suite of publicly available model predictions to allow for the use of kinematic constraints from the Gaia mission. We find that 22+26−8% of all massive binary systems merge prior to the first core-collapse in the system. Of the remainder, 86+11−9% become unbound because of the core-collapse. Remarkably, this rarely produces runaway stars (observationally defined as stars with velocities above 30 km s−1). These are outnumbered by more than an order of magnitude by slower unbound companions, or “walkaway stars”. This is a robust outcome of our simulations and is due to the reversal of the mass ratio prior to the explosion and widening of the orbit, as we show analytically and numerically. For stars more massive than 15 M⊙, we estimate that 10+5−8% are walkaways and only 0.5+1.0−0.4% are runaways, nearly all of which have accreted mass from their companion. Our findings are consistent with earlier studies; however, the low runaway fraction we find is in tension with observed fractions of about 10%. Thus, astrometric data on presently single massive stars can potentially constrain the physics of massive binary evolution. Finally, we show that the high end of the mass distributions of runaway stars is very sensitive to the assumed black hole natal kicks, and we propose this as a potentially stringent test for the explosion mechanism. We also discuss companions remaining bound that can evolve into X-ray and gravitational wave sources."}],"main_file_link":[{"open_access":"1","url":"https://doi.org/10.1051/0004-6361/201833297"}],"date_created":"2023-08-03T10:14:18Z","date_published":"2019-04-11T00:00:00Z","publication":"Astronomy & Astrophysics","day":"11","quality_controlled":"1","oa":1,"_id":"13471","keyword":["Space and Planetary Science","Astronomy and Astrophysics"],"oa_version":"Published Version","doi":"10.1051/0004-6361/201833297","article_number":"A66","author":[{"first_name":"M.","full_name":"Renzo, M.","last_name":"Renzo"},{"first_name":"E.","full_name":"Zapartas, E.","last_name":"Zapartas"},{"last_name":"de Mink","first_name":"S. E.","full_name":"de Mink, S. E."},{"first_name":"Ylva Louise Linsdotter","orcid":"0000-0002-6960-6911","full_name":"Götberg, Ylva Louise Linsdotter","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d","last_name":"Götberg"},{"last_name":"Justham","first_name":"S.","full_name":"Justham, S."},{"first_name":"R. J.","full_name":"Farmer, R. J.","last_name":"Farmer"},{"last_name":"Izzard","first_name":"R. G.","full_name":"Izzard, R. G."},{"last_name":"Toonen","full_name":"Toonen, S.","first_name":"S."},{"full_name":"Sana, H.","first_name":"H.","last_name":"Sana"}],"arxiv":1,"volume":624,"type":"journal_article","month":"04","publication_status":"published"},{"publication_status":"published","month":"03","volume":623,"type":"journal_article","arxiv":1,"author":[{"last_name":"Kerzendorf","full_name":"Kerzendorf, Wolfgang E.","first_name":"Wolfgang E."},{"full_name":"Do, Tuan","first_name":"Tuan","last_name":"Do"},{"last_name":"de Mink","first_name":"Selma E.","full_name":"de Mink, Selma E."},{"last_name":"Götberg","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d","full_name":"Götberg, Ylva Louise Linsdotter","orcid":"0000-0002-6960-6911","first_name":"Ylva Louise Linsdotter"},{"full_name":"Milisavljevic, Dan","first_name":"Dan","last_name":"Milisavljevic"},{"full_name":"Zapartas, Emmanouil","first_name":"Emmanouil","last_name":"Zapartas"},{"full_name":"Renzo, Mathieu","first_name":"Mathieu","last_name":"Renzo"},{"first_name":"Stephen","full_name":"Justham, Stephen","last_name":"Justham"},{"first_name":"Philipp","full_name":"Podsiadlowski, Philipp","last_name":"Podsiadlowski"},{"last_name":"Fesen","full_name":"Fesen, Robert A.","first_name":"Robert A."}],"article_number":"A34","doi":"10.1051/0004-6361/201732206","oa_version":"Published Version","keyword":["Space and Planetary Science","Astronomy and Astrophysics"],"_id":"13472","oa":1,"quality_controlled":"1","day":"27","publication":"Astronomy & Astrophysics","date_published":"2019-03-27T00:00:00Z","date_created":"2023-08-03T10:14:27Z","main_file_link":[{"open_access":"1","url":"https://doi.org/10.1051/0004-6361/201732206"}],"abstract":[{"lang":"eng","text":"Massive stars in binaries can give rise to extreme phenomena such as X-ray binaries and gravitational wave sources after one or both stars end their lives as core-collapse supernovae. Stars in close orbit around a stellar or compact companion are expected to explode as “stripped-envelope supernovae”, showing no (Type Ib/c) or little (Type IIb) signs of hydrogen in the spectra, because hydrogen-rich progenitors are too large to fit. The physical processes responsible for the stripping process and the fate of the companion are still very poorly understood. Aiming to find new clues, we investigate Cas A, which is a very young (∼340 yr) and near (∼3.4 kpc) remnant of a core-collapse supernova. Cas A has been subject to several searches for possible companions, all unsuccessfully. We present new measurements of the proper motions and photometry of stars in the vicinity based on deep HST ACS/WFC and WFC3-IR data. We identify stellar sources that are close enough in projection but using their proper motions we show that none are compatible with being at the location of center at the time of explosion, in agreement with earlier findings. Our photometric measurements allow us to place much deeper (order-of-magnitude) upper limits on the brightness of possible undetected companions. We systematically compare them with model predictions for a wide variety of scenarios. We can confidently rule out the presence of any stellar companion of any reasonable mass and age (main sequence, pre main sequence or stripped) ruling out what many considered to be likely evolutionary scenarios for Type IIb supernova (SN IIb). More exotic scenarios that predict the presence of a compact companion (white dwarf, neutron star or black hole) are still possible as well as scenarios where the progenitor of Cas A was single at the moment of explosion (either because it was truly single, or resulted from a binary that was disrupted, or from a binary merger). The presence of a compact companion would imply that Cas A is of interest to study exotic outcomes of binary evolution. The single-at-death solution would still require fine-tuning of the process that removed most of the envelope through a mass-loss mechanism yet to be identified. We discuss how future constraints from Gaia and even deeper photometric studies may help to place further constraints."}],"title":"No surviving non-compact stellar companion to Cassiopeia A","intvolume":"       623","language":[{"iso":"eng"}],"extern":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"date_updated":"2023-08-09T12:28:17Z","article_processing_charge":"No","article_type":"original","scopus_import":"1","external_id":{"arxiv":["1711.00055"]},"status":"public","year":"2019","publisher":"EDP Sciences","citation":{"ieee":"W. E. Kerzendorf <i>et al.</i>, “No surviving non-compact stellar companion to Cassiopeia A,” <i>Astronomy &#38; Astrophysics</i>, vol. 623. EDP Sciences, 2019.","ama":"Kerzendorf WE, Do T, de Mink SE, et al. No surviving non-compact stellar companion to Cassiopeia A. <i>Astronomy &#38; Astrophysics</i>. 2019;623. doi:<a href=\"https://doi.org/10.1051/0004-6361/201732206\">10.1051/0004-6361/201732206</a>","apa":"Kerzendorf, W. E., Do, T., de Mink, S. E., Götberg, Y. L. L., Milisavljevic, D., Zapartas, E., … Fesen, R. A. (2019). No surviving non-compact stellar companion to Cassiopeia A. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/201732206\">https://doi.org/10.1051/0004-6361/201732206</a>","ista":"Kerzendorf WE, Do T, de Mink SE, Götberg YLL, Milisavljevic D, Zapartas E, Renzo M, Justham S, Podsiadlowski P, Fesen RA. 2019. No surviving non-compact stellar companion to Cassiopeia A. Astronomy &#38; Astrophysics. 623, A34.","short":"W.E. Kerzendorf, T. Do, S.E. de Mink, Y.L.L. Götberg, D. Milisavljevic, E. Zapartas, M. Renzo, S. Justham, P. Podsiadlowski, R.A. Fesen, Astronomy &#38; Astrophysics 623 (2019).","chicago":"Kerzendorf, Wolfgang E., Tuan Do, Selma E. de Mink, Ylva Louise Linsdotter Götberg, Dan Milisavljevic, Emmanouil Zapartas, Mathieu Renzo, Stephen Justham, Philipp Podsiadlowski, and Robert A. Fesen. “No Surviving Non-Compact Stellar Companion to Cassiopeia A.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2019. <a href=\"https://doi.org/10.1051/0004-6361/201732206\">https://doi.org/10.1051/0004-6361/201732206</a>.","mla":"Kerzendorf, Wolfgang E., et al. “No Surviving Non-Compact Stellar Companion to Cassiopeia A.” <i>Astronomy &#38; Astrophysics</i>, vol. 623, A34, EDP Sciences, 2019, doi:<a href=\"https://doi.org/10.1051/0004-6361/201732206\">10.1051/0004-6361/201732206</a>."}},{"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"oa_version":"Published Version","file":[{"date_updated":"2020-07-14T12:47:39Z","relation":"main_file","date_created":"2019-08-05T08:08:59Z","access_level":"open_access","file_id":"6766","creator":"dernst","checksum":"83b9209ed9eefbdcefd89019c5a97805","file_name":"2019_AstronomyAstrophysics_Pranav.pdf","content_type":"application/pdf","file_size":14420451}],"article_number":"A163","doi":"10.1051/0004-6361/201834916","author":[{"full_name":"Pranav, Pratyush","first_name":"Pratyush","last_name":"Pranav"},{"first_name":"Robert J.","full_name":"Adler, Robert J.","last_name":"Adler"},{"last_name":"Buchert","full_name":"Buchert, Thomas","first_name":"Thomas"},{"orcid":"0000-0002-9823-6833","full_name":"Edelsbrunner, Herbert","first_name":"Herbert","id":"3FB178DA-F248-11E8-B48F-1D18A9856A87","last_name":"Edelsbrunner"},{"full_name":"Jones, Bernard J.T.","first_name":"Bernard J.T.","last_name":"Jones"},{"full_name":"Schwartzman, Armin","first_name":"Armin","last_name":"Schwartzman"},{"first_name":"Hubert","full_name":"Wagner, Hubert","last_name":"Wagner","id":"379CA8B8-F248-11E8-B48F-1D18A9856A87"},{"first_name":"Rien","full_name":"Van De Weygaert, Rien","last_name":"Van De Weygaert"}],"month":"07","type":"journal_article","volume":627,"arxiv":1,"publication_status":"published","acknowledgement":"PP is grateful to Julian Borill from the Planck consortium for providing the data, and for the illuminating discussions and inputs. PP also thanks Hans Kristen Eriksen, Anne Ducout, and Francois R. Bouchet for significantly helpful discussions at various stages. The authors collectively thank the anonymous referee for the invaluable comments and suggestions that have added significant value to the contents of the manuscript. PP and RA acknowledge the support of ERC advanced grant Understanding Random Systems through Algebraic Topology (URSAT) (no: 320422, PI: RA). This work is also part of a project that has received funding for PP and TB from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement ERC advanced grant 740021– Advances in Research on THeories of the dark UniverSe (ARTHUS), PI: TB). HE and HW acknowledge the support by the Office of Naval Research, through grant N62909-18-1-2038, and by the DFG Collaborative Research Center TRR 109, “Discretization in Geometry and Dynamics”, through grant I02979-N35 of the Austrian Science Fund (FWF). PP acknowledges the support and use of resources at the NERSC computing center.","isi":1,"project":[{"grant_number":"M62909-18-1-2038","name":"Toward Computational Information Topology","_id":"265683E4-B435-11E9-9278-68D0E5697425"},{"grant_number":"I02979-N35","name":"Persistence and stability of geometric complexes","_id":"2561EBF4-B435-11E9-9278-68D0E5697425","call_identifier":"FWF"}],"quality_controlled":"1","OA_type":"hybrid","OA_place":"publisher","_id":"6756","oa":1,"language":[{"iso":"eng"}],"intvolume":"       627","title":"Unexpected topology of the temperature fluctuations in the cosmic microwave background","date_created":"2019-08-04T21:59:18Z","abstract":[{"text":"We study the topology generated by the temperature fluctuations of the cosmic microwave background (CMB) radiation, as quantified by the number of components and holes, formally given by the Betti numbers, in the growing excursion sets. We compare CMB maps observed by the Planck satellite with a thousand simulated maps generated according to the ΛCDM paradigm with Gaussian distributed fluctuations. The comparison is multi-scale, being performed on a sequence of degraded maps with mean pixel separation ranging from 0.05 to 7.33°. The survey of the CMB over 𝕊2 is incomplete due to obfuscation effects by bright point sources and other extended foreground objects like our own galaxy. To deal with such situations, where analysis in the presence of “masks” is of importance, we introduce the concept of relative homology. The parametric χ2-test shows differences between observations and simulations, yielding p-values at percent to less than permil levels roughly between 2 and 7°, with the difference in the number of components and holes peaking at more than 3σ sporadically at these scales. The highest observed deviation between the observations and simulations for b0 and b1 is approximately between 3σ and 4σ at scales of 3–7°. There are reports of mildly unusual behaviour of the Euler characteristic at 3.66° in the literature, computed from independent measurements of the CMB temperature fluctuations by Planck’s predecessor, the Wilkinson Microwave Anisotropy Probe (WMAP) satellite. The mildly anomalous behaviour of the Euler characteristic is phenomenologically related to the strongly anomalous behaviour of components and holes, or the zeroth and first Betti numbers, respectively. Further, since these topological descriptors show consistent anomalous behaviour over independent measurements of Planck and WMAP, instrumental and systematic errors may be an unlikely source. These are also the scales at which the observed maps exhibit low variance compared to the simulations, and approximately the range of scales at which the power spectrum exhibits a dip with respect to the theoretical model. Non-parametric tests show even stronger differences at almost all scales. Crucially, Gaussian simulations based on power-spectrum matching the characteristics of the observed dipped power spectrum are not able to resolve the anomaly. Understanding the origin of the anomalies in the CMB, whether cosmological in nature or arising due to late-time effects, is an extremely challenging task. Regardless, beyond the trivial possibility that this may still be a manifestation of an extreme Gaussian case, these observations, along with the super-horizon scales involved, may motivate the study of primordial non-Gaussianity. Alternative scenarios worth exploring may be models with non-trivial topology, including topological defect models.","lang":"eng"}],"ddc":["520","530"],"date_published":"2019-07-17T00:00:00Z","day":"17","publication":"Astronomy and Astrophysics","department":[{"_id":"HeEd"}],"citation":{"short":"P. Pranav, R.J. Adler, T. Buchert, H. Edelsbrunner, B.J.T. Jones, A. Schwartzman, H. Wagner, R. Van De Weygaert, Astronomy and Astrophysics 627 (2019).","chicago":"Pranav, Pratyush, Robert J. Adler, Thomas Buchert, Herbert Edelsbrunner, Bernard J.T. Jones, Armin Schwartzman, Hubert Wagner, and Rien Van De Weygaert. “Unexpected Topology of the Temperature Fluctuations in the Cosmic Microwave Background.” <i>Astronomy and Astrophysics</i>. EDP Sciences, 2019. <a href=\"https://doi.org/10.1051/0004-6361/201834916\">https://doi.org/10.1051/0004-6361/201834916</a>.","mla":"Pranav, Pratyush, et al. “Unexpected Topology of the Temperature Fluctuations in the Cosmic Microwave Background.” <i>Astronomy and Astrophysics</i>, vol. 627, A163, EDP Sciences, 2019, doi:<a href=\"https://doi.org/10.1051/0004-6361/201834916\">10.1051/0004-6361/201834916</a>.","ieee":"P. Pranav <i>et al.</i>, “Unexpected topology of the temperature fluctuations in the cosmic microwave background,” <i>Astronomy and Astrophysics</i>, vol. 627. EDP Sciences, 2019.","ama":"Pranav P, Adler RJ, Buchert T, et al. Unexpected topology of the temperature fluctuations in the cosmic microwave background. <i>Astronomy and Astrophysics</i>. 2019;627. doi:<a href=\"https://doi.org/10.1051/0004-6361/201834916\">10.1051/0004-6361/201834916</a>","ista":"Pranav P, Adler RJ, Buchert T, Edelsbrunner H, Jones BJT, Schwartzman A, Wagner H, Van De Weygaert R. 2019. Unexpected topology of the temperature fluctuations in the cosmic microwave background. Astronomy and Astrophysics. 627, A163.","apa":"Pranav, P., Adler, R. J., Buchert, T., Edelsbrunner, H., Jones, B. J. T., Schwartzman, A., … Van De Weygaert, R. (2019). Unexpected topology of the temperature fluctuations in the cosmic microwave background. <i>Astronomy and Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/201834916\">https://doi.org/10.1051/0004-6361/201834916</a>"},"publisher":"EDP Sciences","year":"2019","status":"public","external_id":{"arxiv":["1812.07678"],"isi":["000475839300003"]},"article_processing_charge":"No","scopus_import":"1","article_type":"original","publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"file_date_updated":"2020-07-14T12:47:39Z","date_updated":"2025-05-20T08:01:55Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","has_accepted_license":"1"},{"oa":1,"_id":"11508","quality_controlled":"1","doi":"10.1051/0004-6361/201833528","article_number":"A136","author":[{"orcid":"0000-0003-2871-127X","full_name":"Matthee, Jorryt J","first_name":"Jorryt J","id":"7439a258-f3c0-11ec-9501-9df22fe06720","last_name":"Matthee"},{"full_name":"Sobral, David","first_name":"David","last_name":"Sobral"},{"first_name":"Max","full_name":"Gronke, Max","last_name":"Gronke"},{"last_name":"Paulino-Afonso","full_name":"Paulino-Afonso, Ana","first_name":"Ana"},{"first_name":"Mauro","full_name":"Stefanon, Mauro","last_name":"Stefanon"},{"first_name":"Huub","full_name":"Röttgering, Huub","last_name":"Röttgering"}],"type":"journal_article","volume":619,"arxiv":1,"month":"11","acknowledgement":"JM acknowledges the award of a Huygens PhD fellowship from Leiden University. MG acknowledges support from NASA grant NNX17AK58G. APA, PhD::SPACE fellow, acknowledges support from the FCT through the fellowship PD/BD/52706/2014. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme IDs 294.A-5018, 098.A-0819, 099.A-0254 and 0100.A-0213. We are grateful for the excellent data-sets from the COSMOS and UltraVISTA survey teams. This research was supported by the Munich Institute for Astro- and Particle Physics (MIAPP) of the DFG cluster of excellence “Origin and Structure of the Universe”. We thank the referee for their comments that improved the paper. We also thank Christoph Behrens, Len Cowie, Koki Kakiichi, Peter Laursen, Charlotte Mason, Eros Vanzella, Lewis Weinberger and Johannes Zabl for discussions. We have benefited from the public available programming language Python, including the numpy, matplotlib, scipy and astropy packages (Hunter 2007; Astropy Collaboration 2013), the astronomical imaging tools Swarp (Bertin 2010) and ds9 and the Topcat analysis tool (Taylor 2013).","publication_status":"published","keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: high-redshift / galaxies: formation / dark ages / reionization / first stars / techniques: spectroscopic / intergalactic medium"],"oa_version":"Published Version","article_type":"original","scopus_import":"1","article_processing_charge":"No","date_updated":"2024-10-14T11:31:36Z","publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","citation":{"apa":"Matthee, J. J., Sobral, D., Gronke, M., Paulino-Afonso, A., Stefanon, M., &#38; Röttgering, H. (2018). Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/201833528\">https://doi.org/10.1051/0004-6361/201833528</a>","ista":"Matthee JJ, Sobral D, Gronke M, Paulino-Afonso A, Stefanon M, Röttgering H. 2018. Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe. Astronomy &#38; Astrophysics. 619, A136.","ieee":"J. J. Matthee, D. Sobral, M. Gronke, A. Paulino-Afonso, M. Stefanon, and H. Röttgering, “Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe,” <i>Astronomy &#38; Astrophysics</i>, vol. 619. EDP Sciences, 2018.","ama":"Matthee JJ, Sobral D, Gronke M, Paulino-Afonso A, Stefanon M, Röttgering H. Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe. <i>Astronomy &#38; Astrophysics</i>. 2018;619. doi:<a href=\"https://doi.org/10.1051/0004-6361/201833528\">10.1051/0004-6361/201833528</a>","mla":"Matthee, Jorryt J., et al. “Confirmation of Double Peaked Lyα Emission at z = 6.593: Witnessing a Galaxy Directly Contributing to the Reionisation of the Universe.” <i>Astronomy &#38; Astrophysics</i>, vol. 619, A136, EDP Sciences, 2018, doi:<a href=\"https://doi.org/10.1051/0004-6361/201833528\">10.1051/0004-6361/201833528</a>.","chicago":"Matthee, Jorryt J, David Sobral, Max Gronke, Ana Paulino-Afonso, Mauro Stefanon, and Huub Röttgering. “Confirmation of Double Peaked Lyα Emission at z = 6.593: Witnessing a Galaxy Directly Contributing to the Reionisation of the Universe.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2018. <a href=\"https://doi.org/10.1051/0004-6361/201833528\">https://doi.org/10.1051/0004-6361/201833528</a>.","short":"J.J. Matthee, D. Sobral, M. Gronke, A. Paulino-Afonso, M. Stefanon, H. Röttgering, Astronomy &#38; Astrophysics 619 (2018)."},"publisher":"EDP Sciences","year":"2018","external_id":{"arxiv":["1805.11621"]},"status":"public","abstract":[{"text":"Distant luminous Lyman-α emitters (LAEs) are excellent targets for spectroscopic observations of galaxies in the epoch of reionisation (EoR). We present deep high-resolution (R = 5000) VLT/X-shooter observations, along with an extensive collection of photometric data of COLA1, a proposed double peaked LAE at z = 6.6. We rule out the possibility that COLA1’s emission line is an [OII] doublet at z = 1.475 on the basis of i) the asymmetric red line-profile and flux ratio of the peaks (blue/red=0.31 ± 0.03) and ii) an unphysical [OII]/Hα ratio ([OII]/Hα >  22). We show that COLA1’s observed B-band flux is explained by a faint extended foreground LAE, for which we detect Lyα and [OIII] at z = 2.142. We thus conclude that COLA1 is a real double-peaked LAE at z = 6.593, the first discovered at z >  6. COLA1 is UV luminous (M1500 = −21.6 ± 0.3), has a high equivalent width (EW0,Lyα = 120−40+50 Å) and very compact Lyα emission (r50,Lyα = 0.33−0.04+0.07 kpc). Relatively weak inferred Hβ+[OIII] line-emission from Spitzer/IRAC indicates an extremely low metallicity of Z <  1/20 Z⊙ or reduced strength of nebular lines due to high escape of ionising photons. The small Lyα peak separation of 220 ± 20 km s−1 implies a low HI column density and an ionising photon escape fraction of ≈15 − 30%, providing the first direct evidence that such galaxies contribute actively to the reionisation of the Universe at z >  6. Based on simple estimates, we find that COLA1 could have provided just enough photons to reionise its own ≈0.3 pMpc (2.3 cMpc) bubble, allowing the blue Lyα line to be observed. However, we also discuss alternative scenarios explaining the detected double peaked nature of COLA1. Our results show that future high-resolution observations of statistical samples of double peaked LAEs at z >  5 are a promising probe of the occurrence of ionised regions around galaxies in the EoR.","lang":"eng"}],"main_file_link":[{"url":"https://arxiv.org/abs/1805.11621","open_access":"1"}],"date_created":"2022-07-06T11:14:23Z","date_published":"2018-11-19T00:00:00Z","publication":"Astronomy & Astrophysics","day":"19","extern":"1","language":[{"iso":"eng"}],"intvolume":"       619","title":"Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe"},{"oa":1,"_id":"11618","quality_controlled":"1","doi":"10.1051/0004-6361/201833106","article_number":"A38","author":[{"orcid":"0000-0003-0142-4000","full_name":"Bugnet, Lisa Annabelle","first_name":"Lisa Annabelle","id":"d9edb345-f866-11ec-9b37-d119b5234501","last_name":"Bugnet"},{"last_name":"García","full_name":"García, R. A.","first_name":"R. A."},{"full_name":"Davies, G. R.","first_name":"G. R.","last_name":"Davies"},{"last_name":"Mathur","first_name":"S.","full_name":"Mathur, S."},{"last_name":"Corsaro","full_name":"Corsaro, E.","first_name":"E."},{"last_name":"Hall","first_name":"O. J.","full_name":"Hall, O. J."},{"last_name":"Rendle","full_name":"Rendle, B. M.","first_name":"B. M."}],"volume":620,"arxiv":1,"type":"journal_article","month":"12","acknowledgement":"We thank the anonymous referee for the very useful comments. We would also like to thank M. Benbakoura for his help in analyzing the light curves of several binary systems included in our set of stars. L.B. and R.A.G. acknowledge the support from PLATO and GOLF CNES grants. S.M. acknowledges support from the National Aeronautics and Space Administration under Grant NNX15AF13G, the National Science Foundation grant AST-1411685, and the Ramon y Cajal fellowship no. RYC-2015-17697. E.C. is funded by the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement no. 664931. O.J.H and B.M.R. acknowledge the support of the UK Science and Technology Facilities Council (STFC). Funding for the Stellar Astrophysics Centre is provided by the Danish National Research Foundation (Grant DNRF106). This research has made use of NASA’s Astrophysics Data System. Data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.","publication_status":"published","keyword":["Space and Planetary Science","Astronomy and Astrophysics","asteroseismology / methods","data analysis / stars","oscillations"],"oa_version":"Preprint","scopus_import":"1","article_type":"original","article_processing_charge":"No","date_updated":"2024-10-14T11:40:17Z","publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","citation":{"ama":"Bugnet LA, García RA, Davies GR, et al. FliPer: A global measure of power density to estimate surface gravities of main-sequence solar-like stars and red giants. <i>Astronomy &#38; Astrophysics</i>. 2018;620. doi:<a href=\"https://doi.org/10.1051/0004-6361/201833106\">10.1051/0004-6361/201833106</a>","ieee":"L. A. Bugnet <i>et al.</i>, “FliPer: A global measure of power density to estimate surface gravities of main-sequence solar-like stars and red giants,” <i>Astronomy &#38; Astrophysics</i>, vol. 620. EDP Sciences, 2018.","apa":"Bugnet, L. A., García, R. A., Davies, G. R., Mathur, S., Corsaro, E., Hall, O. J., &#38; Rendle, B. M. (2018). FliPer: A global measure of power density to estimate surface gravities of main-sequence solar-like stars and red giants. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/201833106\">https://doi.org/10.1051/0004-6361/201833106</a>","ista":"Bugnet LA, García RA, Davies GR, Mathur S, Corsaro E, Hall OJ, Rendle BM. 2018. FliPer: A global measure of power density to estimate surface gravities of main-sequence solar-like stars and red giants. Astronomy &#38; Astrophysics. 620, A38.","chicago":"Bugnet, Lisa Annabelle, R. A. García, G. R. Davies, S. Mathur, E. Corsaro, O. J. Hall, and B. M. Rendle. “FliPer: A Global Measure of Power Density to Estimate Surface Gravities of Main-Sequence Solar-like Stars and Red Giants.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2018. <a href=\"https://doi.org/10.1051/0004-6361/201833106\">https://doi.org/10.1051/0004-6361/201833106</a>.","short":"L.A. Bugnet, R.A. García, G.R. Davies, S. Mathur, E. Corsaro, O.J. Hall, B.M. Rendle, Astronomy &#38; Astrophysics 620 (2018).","mla":"Bugnet, Lisa Annabelle, et al. “FliPer: A Global Measure of Power Density to Estimate Surface Gravities of Main-Sequence Solar-like Stars and Red Giants.” <i>Astronomy &#38; Astrophysics</i>, vol. 620, A38, EDP Sciences, 2018, doi:<a href=\"https://doi.org/10.1051/0004-6361/201833106\">10.1051/0004-6361/201833106</a>."},"publisher":"EDP Sciences","year":"2018","external_id":{"arxiv":["1809.05105"]},"status":"public","abstract":[{"lang":"eng","text":"Asteroseismology provides global stellar parameters such as masses, radii, or surface gravities using mean global seismic parameters and effective temperature for thousands of low-mass stars (0.8 M⊙ < M < 3 M⊙). This methodology has been successfully applied to stars in which acoustic modes excited by turbulent convection are measured. Other methods such as the Flicker technique can also be used to determine stellar surface gravities, but only works for log g above 2.5 dex. In this work, we present a new metric called FliPer (Flicker in spectral power density, in opposition to the standard Flicker measurement which is computed in the time domain); it is able to extend the range for which reliable surface gravities can be obtained (0.1 < log g < 4.6 dex) without performing any seismic analysis for stars brighter than Kp < 14. FliPer takes into account the average variability of a star measured in the power density spectrum in a given range of frequencies. However, FliPer values calculated on several ranges of frequency are required to better characterize a star. Using a large set of asteroseismic targets it is possible to calibrate the behavior of surface gravity with FliPer through machine learning. This calibration made with a random forest regressor covers a wide range of surface gravities from main-sequence stars to subgiants and red giants, with very small uncertainties from 0.04 to 0.1 dex. FliPer values can be inserted in automatic global seismic pipelines to either give an estimation of the stellar surface gravity or to assess the quality of the seismic results by detecting any outliers in the obtained νmax values. FliPer also constrains the surface gravities of main-sequence dwarfs using only long-cadence data for which the Nyquist frequency is too low to measure the acoustic-mode properties."}],"date_created":"2022-07-18T14:37:39Z","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1809.05105"}],"date_published":"2018-12-01T00:00:00Z","publication":"Astronomy & Astrophysics","day":"01","extern":"1","language":[{"iso":"eng"}],"intvolume":"       620","title":"FliPer: A global measure of power density to estimate surface gravities of main-sequence solar-like stars and red giants"},{"publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"date_updated":"2022-08-22T07:43:29Z","article_processing_charge":"No","article_type":"letter_note","scopus_import":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publisher":"EDP Sciences","citation":{"mla":"Gandolfi, D., et al. “TESS’s First Planet: A Super-Earth Transiting the Naked-Eye Star π Mensae.” <i>Astronomy &#38; Astrophysics</i>, vol. 619, L10, EDP Sciences, 2018, doi:<a href=\"https://doi.org/10.1051/0004-6361/201834289\">10.1051/0004-6361/201834289</a>.","chicago":"Gandolfi, D., O. Barragán, J. H. Livingston, M. Fridlund, A. B. Justesen, S. Redfield, L. Fossati, et al. “TESS’s First Planet: A Super-Earth Transiting the Naked-Eye Star π Mensae.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2018. <a href=\"https://doi.org/10.1051/0004-6361/201834289\">https://doi.org/10.1051/0004-6361/201834289</a>.","short":"D. Gandolfi, O. Barragán, J.H. Livingston, M. Fridlund, A.B. Justesen, S. Redfield, L. Fossati, S. Mathur, S. Grziwa, J. Cabrera, R.A. García, C.M. Persson, V. Van Eylen, A.P. Hatzes, D. Hidalgo, S. Albrecht, L.A. Bugnet, W.D. Cochran, S. Csizmadia, H. Deeg, P. Eigmüller, M. Endl, A. Erikson, M. Esposito, E. Guenther, J. Korth, R. Luque, P. Montañes Rodríguez, D. Nespral, G. Nowak, M. Pätzold, J. Prieto-Arranz, Astronomy &#38; Astrophysics 619 (2018).","apa":"Gandolfi, D., Barragán, O., Livingston, J. H., Fridlund, M., Justesen, A. B., Redfield, S., … Prieto-Arranz, J. (2018). TESS’s first planet: A super-Earth transiting the naked-eye star π Mensae. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/201834289\">https://doi.org/10.1051/0004-6361/201834289</a>","ista":"Gandolfi D, Barragán O, Livingston JH, Fridlund M, Justesen AB, Redfield S, Fossati L, Mathur S, Grziwa S, Cabrera J, García RA, Persson CM, Van Eylen V, Hatzes AP, Hidalgo D, Albrecht S, Bugnet LA, Cochran WD, Csizmadia S, Deeg H, Eigmüller P, Endl M, Erikson A, Esposito M, Guenther E, Korth J, Luque R, Montañes Rodríguez P, Nespral D, Nowak G, Pätzold M, Prieto-Arranz J. 2018. TESS’s first planet: A super-Earth transiting the naked-eye star π Mensae. Astronomy &#38; Astrophysics. 619, L10.","ieee":"D. Gandolfi <i>et al.</i>, “TESS’s first planet: A super-Earth transiting the naked-eye star π Mensae,” <i>Astronomy &#38; Astrophysics</i>, vol. 619. EDP Sciences, 2018.","ama":"Gandolfi D, Barragán O, Livingston JH, et al. TESS’s first planet: A super-Earth transiting the naked-eye star π Mensae. <i>Astronomy &#38; Astrophysics</i>. 2018;619. doi:<a href=\"https://doi.org/10.1051/0004-6361/201834289\">10.1051/0004-6361/201834289</a>"},"status":"public","external_id":{"arxiv":["1809.07573"]},"year":"2018","date_published":"2018-11-22T00:00:00Z","date_created":"2022-07-18T14:41:16Z","main_file_link":[{"url":"https://arxiv.org/abs/1809.07573","open_access":"1"}],"abstract":[{"text":"We report on the confirmation and mass determination of π Men c, the first transiting planet discovered by NASA’s TESS space mission. π Men is a naked-eye (V = 5.65 mag), quiet G0 V star that was previously known to host a sub-stellar companion (π Men b) on a longperiod (Porb = 2091 days), eccentric (e = 0.64) orbit. Using TESS time-series photometry, combined with Gaia data, published UCLES at AAT Doppler measurements, and archival HARPS at ESO-3.6m radial velocities, we found that π Men c is a close-in planet with an orbital period of Porb = 6.27 days, a mass of Mc = 4.52 ± 0.81 M⊕, and a radius of Rc = 2.06 ± 0.03 R⊕. Based on the planet’s orbital period and size, π Men c is a super-Earth located at, or close to, the radius gap, while its mass and bulk density suggest it may have held on to a significant atmosphere. Because of the brightness of the host star, this system is highly suitable for a wide range of further studies to characterize the planetary atmosphere and dynamical properties. We also performed an asteroseismic analysis of the TESS data and detected a hint of power excess consistent with the seismic values expected for this star, although this result depends on the photometric aperture used to extract the light curve. This marginal detection is expected from pre-launch simulations hinting at the asteroseismic potential of the TESS mission for longer, multi-sector observations and/or for more evolved bright stars.","lang":"eng"}],"day":"22","publication":"Astronomy & Astrophysics","language":[{"iso":"eng"}],"extern":"1","intvolume":"       619","title":"TESS’s first planet: A super-Earth transiting the naked-eye star π Mensae","oa":1,"_id":"11619","quality_controlled":"1","author":[{"last_name":"Gandolfi","first_name":"D.","full_name":"Gandolfi, D."},{"first_name":"O.","full_name":"Barragán, O.","last_name":"Barragán"},{"full_name":"Livingston, J. H.","first_name":"J. H.","last_name":"Livingston"},{"last_name":"Fridlund","full_name":"Fridlund, M.","first_name":"M."},{"last_name":"Justesen","first_name":"A. B.","full_name":"Justesen, A. B."},{"first_name":"S.","full_name":"Redfield, S.","last_name":"Redfield"},{"last_name":"Fossati","first_name":"L.","full_name":"Fossati, L."},{"last_name":"Mathur","first_name":"S.","full_name":"Mathur, S."},{"full_name":"Grziwa, S.","first_name":"S.","last_name":"Grziwa"},{"full_name":"Cabrera, J.","first_name":"J.","last_name":"Cabrera"},{"full_name":"García, R. A.","first_name":"R. A.","last_name":"García"},{"last_name":"Persson","full_name":"Persson, C. M.","first_name":"C. M."},{"full_name":"Van Eylen, V.","first_name":"V.","last_name":"Van Eylen"},{"first_name":"A. P.","full_name":"Hatzes, A. P.","last_name":"Hatzes"},{"last_name":"Hidalgo","first_name":"D.","full_name":"Hidalgo, D."},{"last_name":"Albrecht","first_name":"S.","full_name":"Albrecht, S."},{"first_name":"Lisa Annabelle","orcid":"0000-0003-0142-4000","full_name":"Bugnet, Lisa Annabelle","id":"d9edb345-f866-11ec-9b37-d119b5234501","last_name":"Bugnet"},{"full_name":"Cochran, W. D.","first_name":"W. D.","last_name":"Cochran"},{"full_name":"Csizmadia, Sz.","first_name":"Sz.","last_name":"Csizmadia"},{"last_name":"Deeg","full_name":"Deeg, H.","first_name":"H."},{"last_name":"Eigmüller","first_name":"Ph.","full_name":"Eigmüller, Ph."},{"last_name":"Endl","full_name":"Endl, M.","first_name":"M."},{"last_name":"Erikson","first_name":"A.","full_name":"Erikson, A."},{"last_name":"Esposito","full_name":"Esposito, M.","first_name":"M."},{"last_name":"Guenther","first_name":"E.","full_name":"Guenther, E."},{"last_name":"Korth","full_name":"Korth, J.","first_name":"J."},{"last_name":"Luque","full_name":"Luque, R.","first_name":"R."},{"last_name":"Montañes Rodríguez","full_name":"Montañes Rodríguez, P.","first_name":"P."},{"first_name":"D.","full_name":"Nespral, D.","last_name":"Nespral"},{"last_name":"Nowak","full_name":"Nowak, G.","first_name":"G."},{"full_name":"Pätzold, M.","first_name":"M.","last_name":"Pätzold"},{"full_name":"Prieto-Arranz, J.","first_name":"J.","last_name":"Prieto-Arranz"}],"article_number":"L10","doi":"10.1051/0004-6361/201834289","publication_status":"published","month":"11","volume":619,"arxiv":1,"type":"journal_article","keyword":["Space and Planetary Science","Astronomy and Astrophysics","planetary systems / planets and satellites","detection / planets and satellites","fundamental parameters / planets and satellites","terrestrial planets / stars","fundamental parameters"],"oa_version":"Preprint"},{"status":"public","external_id":{"arxiv":["1803.02379"]},"year":"2018","publisher":"EDP Sciences","citation":{"ista":"Schootemeijer A, Götberg YLL, de Mink SE, Gies D, Zapartas E. 2018. Clues about the scarcity of stripped-envelope stars from the evolutionary state of the sdO+Be binary system φ Persei. Astronomy &#38; Astrophysics. 615, A30.","apa":"Schootemeijer, A., Götberg, Y. L. L., de Mink, S. E., Gies, D., &#38; Zapartas, E. (2018). Clues about the scarcity of stripped-envelope stars from the evolutionary state of the sdO+Be binary system φ Persei. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/201731194\">https://doi.org/10.1051/0004-6361/201731194</a>","ieee":"A. Schootemeijer, Y. L. L. Götberg, S. E. de Mink, D. Gies, and E. Zapartas, “Clues about the scarcity of stripped-envelope stars from the evolutionary state of the sdO+Be binary system φ Persei,” <i>Astronomy &#38; Astrophysics</i>, vol. 615. EDP Sciences, 2018.","ama":"Schootemeijer A, Götberg YLL, de Mink SE, Gies D, Zapartas E. Clues about the scarcity of stripped-envelope stars from the evolutionary state of the sdO+Be binary system φ Persei. <i>Astronomy &#38; Astrophysics</i>. 2018;615. doi:<a href=\"https://doi.org/10.1051/0004-6361/201731194\">10.1051/0004-6361/201731194</a>","mla":"Schootemeijer, A., et al. “Clues about the Scarcity of Stripped-Envelope Stars from the Evolutionary State of the SdO+Be Binary System φ Persei.” <i>Astronomy &#38; Astrophysics</i>, vol. 615, A30, EDP Sciences, 2018, doi:<a href=\"https://doi.org/10.1051/0004-6361/201731194\">10.1051/0004-6361/201731194</a>.","chicago":"Schootemeijer, A., Ylva Louise Linsdotter Götberg, S. E. de Mink, D. Gies, and E. Zapartas. “Clues about the Scarcity of Stripped-Envelope Stars from the Evolutionary State of the SdO+Be Binary System φ Persei.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2018. <a href=\"https://doi.org/10.1051/0004-6361/201731194\">https://doi.org/10.1051/0004-6361/201731194</a>.","short":"A. Schootemeijer, Y.L.L. Götberg, S.E. de Mink, D. Gies, E. Zapartas, Astronomy &#38; Astrophysics 615 (2018)."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publication_identifier":{"issn":["0004-6361"],"eissn":["1432-0746"]},"date_updated":"2023-08-09T12:22:52Z","article_processing_charge":"No","scopus_import":"1","article_type":"original","title":"Clues about the scarcity of stripped-envelope stars from the evolutionary state of the sdO+Be binary system φ Persei","intvolume":"       615","language":[{"iso":"eng"}],"extern":"1","day":"06","publication":"Astronomy & Astrophysics","date_published":"2018-07-06T00:00:00Z","date_created":"2023-08-03T10:14:37Z","main_file_link":[{"open_access":"1","url":"https://doi.org/10.1051/0004-6361/201731194"}],"abstract":[{"text":"Stripped-envelope stars form in binary systems after losing mass through Roche-lobe overflow. They bear astrophysical significance as sources of UV and ionizing radiation in older stellar populations and, if sufficiently massive, as stripped supernova progenitors. Binary evolutionary models predict that they are common, but only a handful of subdwarfs with B-type companions are known. The question is whether a large population of such systems has evaded detection as a result of biases, or whether the model predictions are wrong. We reanalyze the well-studied post-interaction binary φ Persei. Recently, new data have improved the orbital solution of the system, which contains an ~1.2M⊙ stripped-envelope star and a rapidly rotating ~9.6M⊙ Be star. We compare with an extensive grid of evolutionary models using a Bayesian approach and constrain the initial masses of the progenitor to 7.2 ± 0.4M⊙ for the stripped star and 3.8 ± 0.4M⊙ for the Be star. The system must have evolved through near-conservative mass transfer. These findings are consistent with earlier studies. The age we obtain, 57 ± 9 Myr, is in excellent agreement with the age of the α Persei cluster. We note that neither star was initially massive enough to produce a core-collapse supernova, but mass exchange pushed the Be star above the mass threshold. We find that the subdwarf is overluminous for its mass by almost an order of magnitude, compared to the expectations for a helium core burning star. We can only reconcile this if the subdwarf resides in a late phase of helium shell burning, which lasts only 2–3% of the total lifetime as a subdwarf. Assuming continuous star formation implies that up to ~50 less evolved, dimmer subdwarfs exist for each system similar to φ Persei, but have evaded detection so far. Our findings can be interpreted as a strong indication that a substantial population of stripped-envelope stars indeed exists, but has so far evaded detection because of observational biases and lack of large-scale systematic searches.","lang":"eng"}],"quality_controlled":"1","_id":"13473","oa":1,"oa_version":"Published Version","keyword":["Space and Planetary Science","Astronomy and Astrophysics"],"publication_status":"published","month":"07","arxiv":1,"volume":615,"type":"journal_article","author":[{"first_name":"A.","full_name":"Schootemeijer, A.","last_name":"Schootemeijer"},{"full_name":"Götberg, Ylva Louise Linsdotter","orcid":"0000-0002-6960-6911","first_name":"Ylva Louise Linsdotter","last_name":"Götberg","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d"},{"last_name":"de Mink","full_name":"de Mink, S. E.","first_name":"S. E."},{"first_name":"D.","full_name":"Gies, D.","last_name":"Gies"},{"last_name":"Zapartas","first_name":"E.","full_name":"Zapartas, E."}],"article_number":"A30","doi":"10.1051/0004-6361/201731194"},{"oa_version":"Published Version","keyword":["Space and Planetary Science","Astronomy and Astrophysics"],"publication_status":"published","month":"07","type":"journal_article","volume":615,"arxiv":1,"author":[{"first_name":"Ylva Louise Linsdotter","orcid":"0000-0002-6960-6911","full_name":"Götberg, Ylva Louise Linsdotter","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d","last_name":"Götberg"},{"last_name":"de Mink","full_name":"de Mink, S. E.","first_name":"S. E."},{"first_name":"J. H.","full_name":"Groh, J. H.","last_name":"Groh"},{"last_name":"Kupfer","full_name":"Kupfer, T.","first_name":"T."},{"last_name":"Crowther","first_name":"P. A.","full_name":"Crowther, P. A."},{"last_name":"Zapartas","full_name":"Zapartas, E.","first_name":"E."},{"last_name":"Renzo","full_name":"Renzo, M.","first_name":"M."}],"article_number":"A78","doi":"10.1051/0004-6361/201732274","quality_controlled":"1","oa":1,"_id":"13475","intvolume":"       615","title":"Spectral models for binary products: Unifying subdwarfs and Wolf-Rayet stars as a sequence of stripped-envelope stars","language":[{"iso":"eng"}],"extern":"1","day":"17","publication":"Astronomy &amp; Astrophysics","date_published":"2018-07-17T00:00:00Z","date_created":"2023-08-03T10:15:00Z","main_file_link":[{"open_access":"1","url":"https://doi.org/10.1051/0004-6361/201732274"}],"abstract":[{"lang":"eng","text":"Stars stripped of their hydrogen-rich envelope through interaction with a binary companion are generally not considered when accounting for ionizing radiation from stellar populations, despite the expectation that stripped stars emit hard ionizing radiation, form frequently, and live 10–100 times longer than single massive stars. We compute the first grid of evolutionary and spectral models specially made for stars stripped in binaries for a range of progenitor masses (2–20 M⊙) and metallicities ranging from solar to values representative for pop II stars. For stripped stars with masses in the range 0.3–7 M⊙, we find consistently high effective temperatures (20 000–100 000 K, increasing with mass), small radii (0.2–1 R⊙), and high bolometric luminosities, comparable to that of their progenitor before stripping. The spectra show a continuous sequence that naturally bridges subdwarf-type stars at the low-mass end and Wolf-Rayet-like spectra at the high-mass end. For intermediate masses we find hybrid spectral classes showing a mixture of absorption and emission lines. These appear for stars with mass-loss rates of 10−8−10−6 M⊙ yr−1, which have semi-transparent atmospheres. At low metallicity, substantial hydrogen-rich layers are left at the surface and we predict spectra that resemble O-type stars instead. We obtain spectra undistinguishable from subdwarfs for stripped stars with masses up to 1.7 M⊙, which questions whether the widely adopted canonical value of 0.47 M⊙ is uniformly valid. Only a handful of stripped stars of intermediate mass have currently been identified observationally. Increasing this sample will provide necessary tests for the physics of interaction, internal mixing, and stellar winds. We use our model spectra to investigate the feasibility to detect stripped stars next to an optically bright companion and recommend systematic searches for their UV excess and possible emission lines, most notably HeII λ4686 in the optical and HeII λ1640 in the UV. Our models are publicly available for further investigations or inclusion in spectral synthesis simulations."}],"status":"public","external_id":{"arxiv":["1802.03018"]},"year":"2018","publisher":"EDP Sciences","citation":{"apa":"Götberg, Y. L. L., de Mink, S. E., Groh, J. H., Kupfer, T., Crowther, P. A., Zapartas, E., &#38; Renzo, M. (2018). Spectral models for binary products: Unifying subdwarfs and Wolf-Rayet stars as a sequence of stripped-envelope stars. <i>Astronomy &#38;amp; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/201732274\">https://doi.org/10.1051/0004-6361/201732274</a>","ista":"Götberg YLL, de Mink SE, Groh JH, Kupfer T, Crowther PA, Zapartas E, Renzo M. 2018. Spectral models for binary products: Unifying subdwarfs and Wolf-Rayet stars as a sequence of stripped-envelope stars. Astronomy &#38;amp; Astrophysics. 615, A78.","ieee":"Y. L. L. Götberg <i>et al.</i>, “Spectral models for binary products: Unifying subdwarfs and Wolf-Rayet stars as a sequence of stripped-envelope stars,” <i>Astronomy &#38;amp; Astrophysics</i>, vol. 615. EDP Sciences, 2018.","ama":"Götberg YLL, de Mink SE, Groh JH, et al. Spectral models for binary products: Unifying subdwarfs and Wolf-Rayet stars as a sequence of stripped-envelope stars. <i>Astronomy &#38;amp; Astrophysics</i>. 2018;615. doi:<a href=\"https://doi.org/10.1051/0004-6361/201732274\">10.1051/0004-6361/201732274</a>","mla":"Götberg, Ylva Louise Linsdotter, et al. “Spectral Models for Binary Products: Unifying Subdwarfs and Wolf-Rayet Stars as a Sequence of Stripped-Envelope Stars.” <i>Astronomy &#38;amp; Astrophysics</i>, vol. 615, A78, EDP Sciences, 2018, doi:<a href=\"https://doi.org/10.1051/0004-6361/201732274\">10.1051/0004-6361/201732274</a>.","short":"Y.L.L. Götberg, S.E. de Mink, J.H. Groh, T. Kupfer, P.A. Crowther, E. Zapartas, M. Renzo, Astronomy &#38;amp; Astrophysics 615 (2018).","chicago":"Götberg, Ylva Louise Linsdotter, S. E. de Mink, J. H. Groh, T. Kupfer, P. A. Crowther, E. Zapartas, and M. Renzo. “Spectral Models for Binary Products: Unifying Subdwarfs and Wolf-Rayet Stars as a Sequence of Stripped-Envelope Stars.” <i>Astronomy &#38;amp; Astrophysics</i>. EDP Sciences, 2018. <a href=\"https://doi.org/10.1051/0004-6361/201732274\">https://doi.org/10.1051/0004-6361/201732274</a>."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publication_identifier":{"issn":["0004-6361"],"eissn":["1432-0746"]},"date_updated":"2024-10-14T12:22:18Z","article_processing_charge":"No","scopus_import":"1","article_type":"original"},{"oa_version":"Published Version","keyword":["Space and Planetary Science","Astronomy and Astrophysics"],"publication_status":"published","month":"12","volume":608,"arxiv":1,"type":"journal_article","author":[{"first_name":"Ylva Louise Linsdotter","orcid":"0000-0002-6960-6911","full_name":"Götberg, Ylva Louise Linsdotter","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d","last_name":"Götberg"},{"full_name":"de Mink, S. E.","first_name":"S. E.","last_name":"de Mink"},{"full_name":"Groh, J. H.","first_name":"J. H.","last_name":"Groh"}],"article_number":"A11","doi":"10.1051/0004-6361/201730472","quality_controlled":"1","_id":"13476","oa":1,"intvolume":"       608","title":"Ionizing spectra of stars that lose their envelope through interaction with a binary companion: Role of metallicity","language":[{"iso":"eng"}],"extern":"1","day":"01","publication":"Astronomy & Astrophysics","date_published":"2017-12-01T00:00:00Z","main_file_link":[{"url":"https://doi.org/10.1051/0004-6361/201730472","open_access":"1"}],"date_created":"2023-08-03T10:15:09Z","abstract":[{"lang":"eng","text":"Understanding ionizing fluxes of stellar populations is crucial for various astrophysical problems including the epoch of reionization. Short-lived massive stars are generally considered as the main stellar sources. We examine the potential role of less massive stars that lose their envelope through interaction with a binary companion. Here, we focus on the role of metallicity (Z). For this purpose we used the evolutionary code MESA and created tailored atmosphere models with the radiative transfer code CMFGEN. We show that typical progenitors, with initial masses of 12 M⊙, produce hot and compact stars (~ 4 M⊙, 60–80 kK, ~1 R⊙). These stripped stars copiously produce ionizing photons, emitting 60–85% and 30–60% of their energy as HI and HeI ionizing radiation, for Z = 0.0001–0.02, respectively. Their output is comparable to what massive stars emit during their Wolf-Rayet phase, if we account for their longer lifetimes and the favorable slope of the initial mass function. Their relative importance for reionization may be further favored since they emit their photons with a time delay (~ 20 Myr after birth in our fiducial model). This allows time for the dispersal of the birth clouds, allowing the ionizing photons to escape into the intergalactic medium. At low Z, we find that Roche stripping fails to fully remove the H-rich envelope, because of the reduced opacity in the subsurface layers. This is in sharp contrast with the assumption of complete stripping that is made in rapid population synthesis simulations, which are widely used to simulate the binary progenitors of supernovae and gravitational waves. Finally, we discuss the urgency to increase the observed sample of stripped stars to test these models and we discuss how our predictions can help to design efficient observational campaigns."}],"external_id":{"arxiv":["1701.07439"]},"status":"public","year":"2017","publisher":"EDP Sciences","citation":{"mla":"Götberg, Ylva Louise Linsdotter, et al. “Ionizing Spectra of Stars That Lose Their Envelope through Interaction with a Binary Companion: Role of Metallicity.” <i>Astronomy &#38; Astrophysics</i>, vol. 608, A11, EDP Sciences, 2017, doi:<a href=\"https://doi.org/10.1051/0004-6361/201730472\">10.1051/0004-6361/201730472</a>.","chicago":"Götberg, Ylva Louise Linsdotter, S. E. de Mink, and J. H. Groh. “Ionizing Spectra of Stars That Lose Their Envelope through Interaction with a Binary Companion: Role of Metallicity.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2017. <a href=\"https://doi.org/10.1051/0004-6361/201730472\">https://doi.org/10.1051/0004-6361/201730472</a>.","short":"Y.L.L. Götberg, S.E. de Mink, J.H. Groh, Astronomy &#38; Astrophysics 608 (2017).","ista":"Götberg YLL, de Mink SE, Groh JH. 2017. Ionizing spectra of stars that lose their envelope through interaction with a binary companion: Role of metallicity. Astronomy &#38; Astrophysics. 608, A11.","apa":"Götberg, Y. L. L., de Mink, S. E., &#38; Groh, J. H. (2017). Ionizing spectra of stars that lose their envelope through interaction with a binary companion: Role of metallicity. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/201730472\">https://doi.org/10.1051/0004-6361/201730472</a>","ieee":"Y. L. L. Götberg, S. E. de Mink, and J. H. Groh, “Ionizing spectra of stars that lose their envelope through interaction with a binary companion: Role of metallicity,” <i>Astronomy &#38; Astrophysics</i>, vol. 608. EDP Sciences, 2017.","ama":"Götberg YLL, de Mink SE, Groh JH. Ionizing spectra of stars that lose their envelope through interaction with a binary companion: Role of metallicity. <i>Astronomy &#38; Astrophysics</i>. 2017;608. doi:<a href=\"https://doi.org/10.1051/0004-6361/201730472\">10.1051/0004-6361/201730472</a>"},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"date_updated":"2024-10-14T12:22:29Z","article_processing_charge":"No","scopus_import":"1","article_type":"original"},{"publisher":"EDP Sciences","citation":{"apa":"Zapartas, E., de Mink, S. E., Izzard, R. G., Yoon, S.-C., Badenes, C., Götberg, Y. L. L., … Shrotriya, T. S. (2017). Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/201629685\">https://doi.org/10.1051/0004-6361/201629685</a>","ista":"Zapartas E, de Mink SE, Izzard RG, Yoon S-C, Badenes C, Götberg YLL, de Koter A, Neijssel CJ, Renzo M, Schootemeijer A, Shrotriya TS. 2017. Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction. Astronomy &#38; Astrophysics. 601(A&#38;A), A29.","ieee":"E. Zapartas <i>et al.</i>, “Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction,” <i>Astronomy &#38; Astrophysics</i>, vol. 601, no. A&#38;A. EDP Sciences, 2017.","ama":"Zapartas E, de Mink SE, Izzard RG, et al. Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction. <i>Astronomy &#38; Astrophysics</i>. 2017;601(A&#38;A). doi:<a href=\"https://doi.org/10.1051/0004-6361/201629685\">10.1051/0004-6361/201629685</a>","mla":"Zapartas, E., et al. “Delay-Time Distribution of Core-Collapse Supernovae with Late Events Resulting from Binary Interaction.” <i>Astronomy &#38; Astrophysics</i>, vol. 601, no. A&#38;A, A29, EDP Sciences, 2017, doi:<a href=\"https://doi.org/10.1051/0004-6361/201629685\">10.1051/0004-6361/201629685</a>.","chicago":"Zapartas, E., S. E. de Mink, R. G. Izzard, S.-C. Yoon, C. Badenes, Ylva Louise Linsdotter Götberg, A. de Koter, et al. “Delay-Time Distribution of Core-Collapse Supernovae with Late Events Resulting from Binary Interaction.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2017. <a href=\"https://doi.org/10.1051/0004-6361/201629685\">https://doi.org/10.1051/0004-6361/201629685</a>.","short":"E. Zapartas, S.E. de Mink, R.G. Izzard, S.-C. Yoon, C. Badenes, Y.L.L. Götberg, A. de Koter, C.J. Neijssel, M. Renzo, A. Schootemeijer, T.S. Shrotriya, Astronomy &#38; Astrophysics 601 (2017)."},"status":"public","external_id":{"arxiv":["1701.07032"]},"year":"2017","date_updated":"2023-08-09T11:15:49Z","publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"scopus_import":"1","article_type":"original","article_processing_charge":"No","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","language":[{"iso":"eng"}],"extern":"1","title":"Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction","intvolume":"       601","date_published":"2017-05-01T00:00:00Z","abstract":[{"lang":"eng","text":"Most massive stars, the progenitors of core-collapse supernovae, are in close binary systems and may interact with their companion through mass transfer or merging. We undertake a population synthesis study to compute the delay-time distribution of core-collapse supernovae, that is, the supernova rate versus time following a starburst, taking into account binary interactions. We test the systematic robustness of our results by running various simulations to account for the uncertainties in our standard assumptions. We find that a significant fraction, 15+9-8%, of core-collapse supernovae are “late”, that is, they occur 50–200 Myr after birth, when all massive single stars have already exploded. These late events originate predominantly from binary systems with at least one, or, in most cases, with both stars initially being of intermediate mass (4–8 M⊙). The main evolutionary channels that contribute often involve either the merging of the initially more massive primary star with its companion or the engulfment of the remaining core of the primary by the expanding secondary that has accreted mass at an earlier evolutionary stage. Also, the total number of core-collapse supernovae increases by 14+15-14% because of binarity for the same initial stellar mass. The high rate implies that we should have already observed such late core-collapse supernovae, but have not recognized them as such. We argue that φ Persei is a likely progenitor and that eccentric neutron star – white dwarf systems are likely descendants. Late events can help explain the discrepancy in the delay-time distributions derived from supernova remnants in the Magellanic Clouds and extragalactic type Ia events, lowering the contribution of prompt Ia events. We discuss ways to test these predictions and speculate on the implications for supernova feedback in simulations of galaxy evolution."}],"date_created":"2023-08-03T10:15:18Z","main_file_link":[{"url":"https://doi.org/10.1051/0004-6361/201629685","open_access":"1"}],"publication":"Astronomy & Astrophysics","day":"01","quality_controlled":"1","oa":1,"_id":"13477","issue":"A&A","keyword":["Space and Planetary Science","Astronomy and Astrophysics"],"oa_version":"Published Version","author":[{"last_name":"Zapartas","full_name":"Zapartas, E.","first_name":"E."},{"first_name":"S. E.","full_name":"de Mink, S. E.","last_name":"de Mink"},{"last_name":"Izzard","full_name":"Izzard, R. G.","first_name":"R. G."},{"last_name":"Yoon","full_name":"Yoon, S.-C.","first_name":"S.-C."},{"full_name":"Badenes, C.","first_name":"C.","last_name":"Badenes"},{"last_name":"Götberg","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d","full_name":"Götberg, Ylva Louise Linsdotter","orcid":"0000-0002-6960-6911","first_name":"Ylva Louise Linsdotter"},{"last_name":"de Koter","full_name":"de Koter, A.","first_name":"A."},{"first_name":"C. J.","full_name":"Neijssel, C. J.","last_name":"Neijssel"},{"first_name":"M.","full_name":"Renzo, M.","last_name":"Renzo"},{"last_name":"Schootemeijer","full_name":"Schootemeijer, A.","first_name":"A."},{"last_name":"Shrotriya","full_name":"Shrotriya, T. S.","first_name":"T. S."}],"doi":"10.1051/0004-6361/201629685","article_number":"A29","publication_status":"published","arxiv":1,"type":"journal_article","volume":601,"month":"05"},{"article_processing_charge":"No","scopus_import":"1","article_type":"original","publication_identifier":{"issn":["0004-6361"],"eissn":["1432-0746"]},"date_updated":"2024-10-14T12:22:01Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","citation":{"mla":"Götberg, Ylva Louise Linsdotter, et al. “Long-Term Stability of the HR 8799 Planetary System without Resonant Lock.” <i>Astronomy &#38; Astrophysics</i>, vol. 592, A147, EDP Sciences, 2016, doi:<a href=\"https://doi.org/10.1051/0004-6361/201526309\">10.1051/0004-6361/201526309</a>.","short":"Y.L.L. Götberg, M.B. Davies, A.J. Mustill, A. Johansen, R.P. Church, Astronomy &#38; Astrophysics 592 (2016).","chicago":"Götberg, Ylva Louise Linsdotter, Melvyn B. Davies, Alexander J. Mustill, Anders Johansen, and Ross P. Church. “Long-Term Stability of the HR 8799 Planetary System without Resonant Lock.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2016. <a href=\"https://doi.org/10.1051/0004-6361/201526309\">https://doi.org/10.1051/0004-6361/201526309</a>.","apa":"Götberg, Y. L. L., Davies, M. B., Mustill, A. J., Johansen, A., &#38; Church, R. P. (2016). Long-term stability of the HR 8799 planetary system without resonant lock. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/201526309\">https://doi.org/10.1051/0004-6361/201526309</a>","ista":"Götberg YLL, Davies MB, Mustill AJ, Johansen A, Church RP. 2016. Long-term stability of the HR 8799 planetary system without resonant lock. Astronomy &#38; Astrophysics. 592, A147.","ama":"Götberg YLL, Davies MB, Mustill AJ, Johansen A, Church RP. Long-term stability of the HR 8799 planetary system without resonant lock. <i>Astronomy &#38; Astrophysics</i>. 2016;592. doi:<a href=\"https://doi.org/10.1051/0004-6361/201526309\">10.1051/0004-6361/201526309</a>","ieee":"Y. L. L. Götberg, M. B. Davies, A. J. Mustill, A. Johansen, and R. P. Church, “Long-term stability of the HR 8799 planetary system without resonant lock,” <i>Astronomy &#38; Astrophysics</i>, vol. 592. EDP Sciences, 2016."},"publisher":"EDP Sciences","year":"2016","external_id":{"arxiv":["1606.07819"]},"status":"public","date_created":"2023-08-03T10:15:28Z","main_file_link":[{"open_access":"1","url":"https://doi.org/10.1051/0004-6361/201526309"}],"abstract":[{"lang":"eng","text":"HR 8799 is a star accompanied by four massive planets on wide orbits. The observed planetary configuration has been shown to be unstable on a timescale much shorter than the estimated age of the system (~30 Myr) unless the planets are locked into mean motion resonances. This condition is characterised by small-amplitude libration of one or more resonant angles that stabilise the system by preventing close encounters. We simulate planetary systems similar to the HR 8799 planetary system, exploring the parameter space in separation between the orbits, planetary masses and distance from the Sun to the star. We find systems that look like HR 8799 and remain stable for longer than the estimated age of HR 8799. None of our systems are forced into resonances. We find, with nominal masses (Mb = 5 MJup and Mc,d,e = 7 MJup) and in a narrow range of orbit separations, that 5 of 100 systems match the observations and lifetime. Considering a broad range of orbit separations, we find 12 of 900 similar systems. The systems survive significantly longer because of their slightly increased initial orbit separations compared to assuming circular orbits from the observed positions. A small increase in separation leads to a significant increase in survival time. The low eccentricity the orbits develop from gravitational interaction is enough for the planets to match the observations. With lower masses, but still comfortably within the estimated planet mass uncertainty, we find 18 of 100 matching and long-lived systems in a narrow orbital separation range. In the broad separation range, we find 82 of 900 matching systems. Our results imply that the planets in the HR 8799 system do not have to be in strong mean motion resonances. We also investigate the future of wide-orbit planetary systems using our HR 8799 analogues. We find that 80% of the systems have two planets left after strong planet-planet scattering and these are on eccentric orbits with semi-major axes of a1 ~ 10 AU and a2 ~ 30−1000 AU. We speculate that other wide-orbit planetary systems, such as AB Pic and HD 106906, are the remnants of HR 8799 analogues that underwent close encounters and dynamical instability."}],"date_published":"2016-08-18T00:00:00Z","day":"18","publication":"Astronomy & Astrophysics","extern":"1","language":[{"iso":"eng"}],"title":"Long-term stability of the HR 8799 planetary system without resonant lock","intvolume":"       592","oa":1,"_id":"13478","quality_controlled":"1","article_number":"A147","doi":"10.1051/0004-6361/201526309","author":[{"full_name":"Götberg, Ylva Louise Linsdotter","orcid":"0000-0002-6960-6911","first_name":"Ylva Louise Linsdotter","last_name":"Götberg","id":"d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d"},{"last_name":"Davies","first_name":"Melvyn B.","full_name":"Davies, Melvyn B."},{"last_name":"Mustill","first_name":"Alexander J.","full_name":"Mustill, Alexander J."},{"last_name":"Johansen","first_name":"Anders","full_name":"Johansen, Anders"},{"last_name":"Church","first_name":"Ross P.","full_name":"Church, Ross P."}],"month":"08","volume":592,"type":"journal_article","arxiv":1,"publication_status":"published","keyword":["Space and Planetary Science","Astronomy and Astrophysics"],"oa_version":"Published Version"}]