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7 Publications visible to you, out of a total of 7
Contact tracing of binary stars: Pathways to stellar mergers

Abstract (Expand)

Stellar mergers are responsible for a wide variety of phenomena such as rejuvenated blue stragglers, highly magnetised stars, spectacular transients, iconic nebulae, and stars with peculiar surface … chemical abundances and rotation rates. Before stars merge, they enter a contact phase. Here, we investigate which initial binary-star configurations lead to contact and classical common-envelope (CE) phases and assess the likelihood of a subsequent merger. To this end, we computed a grid of about 6000 detailed 1D binary evolution models with initial component masses of 0.5 − 20.0 M⊙ at solar metallicity. Both components were evolved, and rotation and tides were taken into account. We identified five mechanisms that lead to contact and mergers: runaway mass transfer, mass loss through the outer Lagrange point L2, expansion of the accretor, orbital decay because of tides, and non-conservative mass transfer. At least 40% of mass-transferring binaries with initial primary-star masses of 5 − 20 M⊙ evolve into a contact phase; > 12% and > 19% likely merge and evolve into a CE phase, respectively. Because of the non-conservative mass transfer in our models, classical CE evolution from late Case-B and Case-C binaries is only found for initial mass ratios qi < 0.15 − 0.35. For larger mass ratios, we find stable mass transfer. In early Case-B binaries, contact occurs for initial mass ratios qi < 0.15 − 0.35, while in Case-A mass transfer, this is the case for all qi in binaries with the initially closest orbits and qi < 0.35 for initially wider binaries. Our models predict that most Case-A binaries with mass ratios of q < 0.5 upon contact mainly get into contact because of runaway mass transfer and accretor expansion on a thermal timescale, with subsequent L2-overflow in more than half of the cases. Thus, these binaries likely merge quickly after establishing contact or remain in contact only for a thermal timescale. On the contrary, Case-A contact binaries with higher mass ratios form through accretor expansion on a nuclear timescale and can thus give rise to long-lived contact phases before a possible merger. Observationally, massive contact binaries are almost exclusively found with mass ratios q > 0.5, confirming our model expectations. Because of non-conservative mass transfer with mass transfer efficiencies of 15 − 65%, 5 − 25%, and 25 − 50% in Case-A, -B, and -C mass transfer, respectively (for primary-star masses above 3 M⊙), our contact, merger, and classical CE incidence rates are conservative lower limits. With more conservative mass transfer, these incidences would increase. Moreover, in most binaries, the non-accreted mass cannot be ejected, raising the question of the further evolution of such systems. The non-accreted mass may settle into circumstellar and circumbinary disks, but could also lead to further contact systems and mergers. Overall, contact binaries are a frequent and fascinating result of binary mass transfer of which the exact outcomes still remain to be understood and explored further.

Authors: J. Henneco, F. R. N. Schneider, E. Laplace

Date Published: 1st Feb 2024

Publication Type: Journal

X-Shooting ULLYSES: Massive stars at low metallicity. I. Project description

Abstract (Expand)

Observations of individual massive stars, super-luminous supernovae, gamma-ray bursts, and gravitational wave events involving spectacular black hole mergers indicate that the low-metallicity Universe … is fundamentally different from our own Galaxy. Many transient phenomena will remain enigmatic until we achieve a firm understanding of the physics and evolution of massive stars at low metallicity (Z). The Hubble Space Telescope has devoted 500 orbits to observing ∼250 massive stars at low Z in the ultraviolet (UV) with the COS and STIS spectrographs under the ULLYSES programme. The complementary X-Shooting ULLYSES (XShootU) project provides an enhanced legacy value with high-quality optical and near-infrared spectra obtained with the wide-wavelength coverage X-shooter spectrograph at ESO’s Very Large Telescope. We present an overview of the XShootU project, showing that combining ULLYSES UV and XShootU optical spectra is critical for the uniform determination of stellar parameters such as effective temperature, surface gravity, luminosity, and abundances, as well as wind properties such as mass-loss rates as a function of Z. As uncertainties in stellar and wind parameters percolate into many adjacent areas of astrophysics, the data and modelling of the XShootU project is expected to be a game changer for our physical understanding of massive stars at low Z. To be able to confidently interpret James Webb Space Telescope spectra of the first stellar generations, the individual spectra of low-Z stars need to be understood, which is exactly where XShootU can deliver. Table B.1 and full Table B.2 are available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (ftp://130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/675/A154 Based on observations collected at the European Southern Observatory under ESO programme 106.211Z.001.

Authors: Jorick S. Vink, A. Mehner, P. A. Crowther, A. Fullerton, M. Garcia, F. Martins, N. Morrell, L. M. Oskinova, N. St-Louis, A. ud-Doula, A. A. C. Sander, H. Sana, J. -C. Bouret, B. Kubátová, P. Marchant, L. P. Martins, A. Wofford, J. Th. van Loon, O. Grace Telford, Y. Götberg, D. M. Bowman, C. Erba, V. M. Kalari, M. Abdul-Masih, T. Alkousa, F. Backs, C. L. Barbosa, S. R. Berlanas, M. Bernini-Peron, J. M. Bestenlehner, R. Blomme, J. Bodensteiner, S. A. Brands, C. J. Evans, A. David-Uraz, F. A. Driessen, K. Dsilva, S. Geen, V. M. A. Gómez-González, L. Grassitelli, W. -R. Hamann, C. Hawcroft, A. Herrero, E. R. Higgins, D. John Hillier, R. Ignace, A. G. Istrate, L. Kaper, N. D. Kee, C. Kehrig, Z. Keszthelyi, J. Klencki, A. de Koter, R. Kuiper, E. Laplace, C. J. K. Larkin, R. R. Lefever, C. Leitherer, D. J. Lennon, L. Mahy, J. Maíz Apellániz, G. Maravelias, W. Marcolino, A. F. McLeod, S. E. de Mink, F. Najarro, M. S. Oey, T. N. Parsons, D. Pauli, M. G. Pedersen, R. K. Prinja, V. Ramachandran, M. C. Ramírez-Tannus, G. N. Sabhahit, A. Schootemeijer, S. Reyero Serantes, T. Shenar, G. S. Stringfellow, N. Sudnik, F. Tramper, L. Wang

Date Published: 1st Jul 2023

Publication Type: Journal

Bimodal Black Hole Mass Distribution and Chirp Masses of Binary Black Hole Mergers

Abstract

Not specified

Authors: Fabian R. N. Schneider, Philipp Podsiadlowski, Eva Laplace

Date Published: 15th Jun 2023

Publication Type: Journal

Nucleosynthesis of Binary-stripped Stars

Abstract (Expand)

The cosmic origin of the elements, the fundamental chemical building blocks of the universe, is still uncertain. Binary interactions play a key role in the evolution of many massive stars, yet their … impact on chemical yields is poorly understood. Using the MESA stellar evolution code, we predict the chemical yields ejected in wind mass loss and the supernovae of single and binary-stripped stars. We do this with a large 162-isotope nuclear network at solar metallicity. We find that binary-stripped stars are more effective producers of the elements than single stars, due to their increased mass loss and an increased chance to eject their envelopes during a supernova. This increased production by binaries varies across the periodic table, with F and K being more significantly produced by binary-stripped stars than single stars. We find that the 12C/13C could be used as an indicator of the conservativeness of mass transfer, as 13C is preferentially ejected during mass transfer while 12C is preferentially ejected during wind mass loss. We identify a number of gamma-ray-emitting radioactive isotopes that may be used to help constrain progenitor and explosion models of core-collapse supernovae with next-generation gamma-ray detectors. For single stars we find that 44V and 52Mn are strong probes of the explosion model, while for binary-stripped stars it is 48Cr. Our findings highlight that binary-stripped stars are not equivalent to two single stars and that detailed stellar modeling is needed to predict their final nucleosynthetic yields.

Authors: R. Farmer, E. Laplace, Jing-ze Ma, S. E. de Mink, S. Justham

Date Published: 12th May 2023

Publication Type: Journal

Bringing Stellar Evolution and Feedback Together: Summary of Proposals from the Lorentz Center Workshop

Abstract (Expand)

Stars strongly impact their environment, and shape structures on all scales throughout the universe, in a process known as "feedback." Due to the complexity of both stellar evolution and the … physics of larger astrophysical structures, there remain many unanswered questions about how feedback operates and what we can learn about stars by studying their imprint on the wider universe. In this white paper, we summarize discussions from the Lorentz Center meeting "Bringing Stellar Evolution and Feedback Together" in 2022 April and identify key areas where further dialog can bring about radical changes in how we view the relationship between stars and the universe they live in.

Authors: Sam Geen, Poojan Agrawal, Paul A. Crowther, B. W. Keller, Alex de Koter, Zsolt Keszthelyi, Freeke van de Voort, Ahmad A. Ali, Frank Backs, Lars Bonne, Vittoria Brugaletta, Annelotte Derkink, Sylvia Ekström, Yvonne A. Fichtner, Luca Grassitelli, Ylva Götberg, Erin R. Higgins, Eva Laplace, Kong You Liow, Marta Lorenzo, Anna F. McLeod, Georges Meynet, Megan Newsome, G. André Oliva, Varsha Ramachandran, Martin P. Rey, Steven Rieder, Emilio Romano-Díaz, Gautham Sabhahit, Andreas A. C. Sander, Rafia Sarwar, Hanno Stinshoff, Mitchel Stoop, Dorottya Szécsi, Maxime Trebitsch, Jorick S. Vink, Ethan Winch

Date Published: 9th Mar 2023

Publication Type: Journal

Horizons: nuclear astrophysics in the 2020s and beyond

Abstract (Expand)

Abstract Nuclear astrophysics is a field at the intersection of nuclear physics and astrophysics, which seeks to understand the nuclear engines of astronomical objects and the origin of the chemical …the origin of the chemical elements. This white paper summarizes progress and status of the field, the new open questions that have emerged, and the tremendous scientific opportunities that have opened up with major advances in capabilities across an ever growing number of disciplines and subfields that need to be integrated. We take a holistic view of the field discussing the unique challenges and opportunities in nuclear astrophysics in regards to science, diversity, education, and the interdisciplinarity and breadth of the field. Clearly nuclear astrophysics is a dynamic field with a bright future that is entering a new era of discovery opportunities.

Authors: H Schatz, A D Becerril Reyes, A Best, E F Brown, K Chatziioannou, K A Chipps, C M Deibel, R Ezzeddine, D K Galloway, C J Hansen, F Herwig, A P Ji, M Lugaro, Z Meisel, D Norman, J S Read, L F Roberts, A Spyrou, I Tews, F X Timmes, C Travaglio, N Vassh, C Abia, P Adsley, S Agarwal, M Aliotta, W Aoki, A Arcones, A Aryan, A Bandyopadhyay, A Banu, D W Bardayan, J Barnes, A Bauswein, T C Beers, J Bishop, T Boztepe, B Côté, M E Caplan, A E Champagne, J A Clark, M Couder, A Couture, S E de Mink, S Debnath, R J deBoer, J den Hartogh, P Denissenkov, V Dexheimer, I Dillmann, J E Escher, M A Famiano, R Farmer, R Fisher, C Fröhlich, A Frebel, C Fryer, G Fuller, A K Ganguly, S Ghosh, B K Gibson, T Gorda, K N Gourgouliatos, V Graber, M Gupta, W C Haxton, A Heger, W R Hix, W C G Ho, E M Holmbeck, A A Hood, S Huth, G Imbriani, R G Izzard, R Jain, H Jayatissa, Z Johnston, T Kajino, A Kankainen, G G Kiss, A Kwiatkowski, M La Cognata, A M Laird, L Lamia, P Landry, E Laplace, K D Launey, D Leahy, G Leckenby, A Lennarz, B Longfellow, A E Lovell, W G Lynch, S M Lyons, K Maeda, E Masha, C Matei, J Merc, B Messer, F Montes, A Mukherjee, M R Mumpower, D Neto, B Nevins, W G Newton, L Q Nguyen, K Nishikawa, N Nishimura, F M Nunes, E O’Connor, B W O’Shea, W-J Ong, S D Pain, M A Pajkos, M Pignatari, R G Pizzone, V M Placco, T Plewa, B Pritychenko, A Psaltis, D Puentes, Y-Z Qian, D Radice, D Rapagnani, B M Rebeiro, R Reifarth, A L Richard, N Rijal, I U Roederer, J S Rojo, J S K, Y Saito, A Schwenk, M L Sergi, R S Sidhu, A Simon, T Sivarani, Á Skúladóttir, M S Smith, A Spiridon, T M Sprouse, S Starrfield, A W Steiner, F Strieder, I Sultana, R Surman, T Szücs, A Tawfik, F Thielemann, L Trache, R Trappitsch, M B Tsang, A Tumino, S Upadhyayula, J O Valle Martínez, M Van der Swaelmen, C Viscasillas Vázquez, A Watts, B Wehmeyer, M Wiescher, C Wrede, J Yoon, R G T Zegers, M A Zermane, M Zingale

Date Published: 15th Nov 2022

Publication Type: Journal

TULIPS: A Tool for Understanding the Lives, Interiors, and Physics of Stars

Abstract (Expand)

Understanding the lives and interior structures of stellar objects is a fundamental objective of astrophysics. Research in this domain often relies on the visualization of astrophysical data, for … instance, the results of theoretical simulations. However, the diagrams commonly employed to this effect are usually static, complex, and can sometimes be non-intuitive or even counter-intuitive to newcomers in the field. To address some of these issues, this paper introduces TULIPS, a python package that generates novel diagrams and animations of the structure and evolution of stellar objects. TULIPS visualizes the output of one-dimensional physical simulations and is currently optimized for the MESA stellar evolution code. Utilizing the inherent spherical symmetry of such simulations, TULIPS represents the physical properties of stellar objects as the attributes of circles. This enables an intuitive representation of the evolution, energy generation and loss processes, composition, and interior properties of stellar objects, while retaining quantitative information. Users can interact with the output videos and diagrams. The capabilities of TULIPS are showcased by example applications that include a Sun-like star, a massive star, a low-metallicity star, and an accreting white dwarf. Diagrams generated with TULIPS are compared to the Hertzsprung-Russell diagram and to the Kippenhahn diagram, and their advantages and challenges are discussed. TULIPS is open source and free. Aside from being a research tool, it can be used for preparing teaching and public outreach material.

Author: E. Laplace

Date Published: 2022

Publication Type: Journal

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