GAA - Grup d'Astronomia i Astrofísica: Recent submissions

Now showing items 1-12 of 377

    • 3D hydrodynamic simulations of white dwarf-main-sequence star collisions-II. Off-centre collisions 

      van der Merwe, Christian; Mohamed, Shazrene; José Pont, Jordi; Shara, Michael; Kaminski, Tomasz (Oxford University Press, 2025-04-01)
      Article
      Open Access
      Stellar collisions have garnered renewed attention for their role in the formation of peculiar objects, such as blue stragglers, and their potential to explain transients with atypical observational and spectroscopic ...

    • The initial mass function based on the full-sky 20 pc census of ~3600 stars and brown dwarfs 

      Kirkpatrick, J. Davy; Marocco, F.; Gelino, Christopher R.; Raghu, Yadukrishna; Faherty, Jacqueline K.; Bardalez Gagliuffi, Daniella C.; Schurr, Steven D.; Apps, Kevin; Schneider, Adam C.; Meisner, Aaron M.; Kuchner, Marc J.; Caselden, Dan; Laurence Smart, Richard; Casewell, Sarah; Raddi, Roberto (2024-04-01)
      Article
      Open Access
      A complete accounting of nearby objects—from the highest-mass white dwarf progenitors down to low-mass brown dwarfs—is now possible, thanks to an almost complete set of trigonometric parallax determinations from Gaia, ...

    • Efficient area coverage planning using approximation tiling heuristics for mosaic imaging with agile spacecraft 

      Betriu Roure, Paula; Soria Guerrero, Manel; Gutiérrez Cabello, Jordi; Andía, Diego; Llopis, Marcel (2024-12-12)
      Article
      Restricted access - publisher's policy
      This work focuses on the Area Coverage Planning Problem (ACPP) for optical cameras onboard agile spacecraft in space exploration missions. The objective is to determine the optimal observation path of the camera’s boresight ...

    • The white dwarf binary pathways survey - X. Gaia orbits for known UV excess binaries 

      Garbutt, James; Parsons, Steven G.; Toloza, Odette; Gänsicke, Boris T.; Hernandez, Stephania; Koester, Detlev; Lagos, Felipe; Raddi, Roberto; Rebassa Mansergas, Alberto; Ren, Juanjuan; Schreiber, Mathias R.; Zorotovic, Mónica (Oxford University Press, 2024-03-19)
      Article
      Open Access
      White dwarfs with an F, G, or K type companion represent the last common ancestor for a plethora of exotic systems throughout the galaxy, though to this point very few of them have been fully characterized in terms of ...

    • Exsolution process in white dwarf stars 

      Camisassa, María Eugenia; Baiko, Denis A.; Torres Gil, Santiago; Rebassa Mansergas, Alberto (EDP Sciences, 2024-03-11)
      Article
      Open Access
      Context. White dwarf stars are considered to be suitable cosmic laboratories for studying the physics of dense plasma. Furthermore, the use of white dwarf stars as cosmic clocks to date stellar populations and main sequence ...

    • A spectroscopic and kinematic survey of fast hot subdwarfs 

      Geier, Stephan; Heber, Ulrich; Irrgang, Andreas; Dorsch, Matti; Bastian, A.; Neunteufel, Patrick; Kupfer, Thomas; Bloemen, Steven; Kreuzer, Simon; Möller, Leandro; Schindewolf, Marcus; Schneider, David; Ziegerer, E.; Raddi, Roberto (EDP Sciences, 2024-10-22)
      Article
      Open Access
      Hot subdwarfs (sdO/B) are the stripped helium cores of red giants formed via binary interactions. Close hot subdwarf binaries with massive white dwarf companions have been proposed as possible progenitors of thermonuclear ...

    • Main sequence dynamo magnetic fields emerging in the white dwarf phase 

      Camisassa, María Eugenia; Fuentes, José Rafael; Schreiber, Matthias R.; Rebassa Mansergas, Alberto; Torres Gil, Santiago; Raddi, Roberto; Domínguez Aguilera, Inmaculada (EDP Sciences, 2024-11-26)
      Article
      Open Access
      Recent observations of volume-limited samples of magnetic white dwarfs (WD) have revealed a higher incidence of magnetism in older stars. Specifically, these studies indicate that magnetism is more prevalent in WDs with ...

    • J-PLUS: The fraction of calcium white dwarfs along the cooling sequence 

      López Sanjuan, Carlos; Tremblay, Pier Emmanuel; O'Brien, Mairi; Spinoso, Daniele; Ederoclite, Alessandro; Vázquez Ramió, Héctor; Cenarro Lagunas, Andrés Javier; Marín Franch, Antonio; Civera, Tamara; Carrasco Martínez, Josep Manel; Gänsicke, Boris T.; Gentile Fusillo, Nicola; Rebassa Mansergas, Alberto (EDP Sciences, 2024-11-15)
      Article
      Open Access
      We used the Javalambre Photometric Local Universe Survey (J-PLUS) second data release (DR2) photometry in 12 optical bands over 2176 deg2 to estimate the fraction of white dwarfs with the presence of CaII H+K absorption ...

    • Characterisation of the stellar wind in Cyg X-1 via modelling of colour-colour diagrams 

      Lai, Eleonora Veronica; Marco, Barbara de; Cavecchi, Yuri; el Mellah, Ileyk; Cinus, M.; Diez, C. M.; Grinberg, Victoria; Zdziarski, Andrzej A.; Uttley, Phil; Bachetti, Matteo; José Pont, Jordi; Rózanska, Agata; Wilms, Jörn; Sala Cladellas, Glòria (EDP Sciences, 2024-10-29)
      Article
      Open Access
      Context. Cygnus X-1 (Cyg X-1) is a high-mass X-ray binary where accretion onto the black hole (BH) is mediated by the stellar wind from the blue supergiant companion star HDE 226868. Due to its inclination, the system is ...

    • A population synthesis study of the Gaia 100 pc unresolved white dwarf-main-sequence binary population 

      Santos García, Alejandro; Torres Gil, Santiago; Rebassa Mansergas, Alberto; Brown, Alex J. (EDP Sciences, 2025-03)
      Article
      Open Access
      Context. Binaries consisting of a white dwarf and a main-sequence star (WDMSs) are excellent tools for studying a wide variety of open problems in modern astronomy. However, due to selection effects, the currently known ...

    • Primeval very low-mass stars and brown dwarfs – VIII. The first age benchmark L subdwarf, a wide companion to a halo white dwarf 

      Zhang, ZengHua; Raddi, Roberto; Burgasser, Adam; Casewell, Sarah; Laurence Smart, Richard; Galvez Ortiz, Maria Cruz; Jones, H.; Baig, Sayan; Lodieu, Nicolas; Gauza, Bartosz; Pavlenko, Ya; Jiao, Ya Feng; Zhao, Zongbao; Zhou, Siyan; Pinfield, D. J. (Oxford University Press, 2024-08-05)
      Article
      Open Access
      We report the discovery of five white dwarf + ultracool dwarf systems identified as common proper motion wide binaries in the Gaia Catalogue of Nearby Stars. The discoveries include a white dwarf + L subdwarf binary, VVV ...

    • PHL 5038AB: is the brown dwarf causing pollution of its white dwarf host star? 

      Casewell, Sarah; Debes, John J.; Dupuy, Trent J.; Dufour, Pierre; Bonsor, Amy; Rebassa Mansergas, Alberto; Murillo Ojeda, Raquel (Oxford University Press, 2024-04-25)
      Article
      Open Access
      We present new results on PHL 5038AB, a widely separated binary system composed of a white dwarf and a brown dwarf, refining the white and brown dwarf parameters and determining the binary separation to be au. New spectra ...