Exploració per tema "Galaxies"

Ara es mostren els items 1-20 de 25

    • Breaking the habit: the peculiar 2016 eruption of the unique recurrent nova M31N 2008-12a 

      Henze, Martin; Darnley, Matt J.; Williams, Steven Charles; Sala Cladellas, Glòria; José Pont, Jordi (2018-04-10)
      Article
      Accés obert

    • Deep optical images of malin 1 reveal new features 

      Galaz, Gaspar; Milovic, Carlos; Suc, Vincent; Busta, Luis; Lizana, Guadalupe; Infante, Leopoldo; Royo Royo, Santiago (2015-12-20)
      Article
      Accés obert
      We present Megacam deep optical images (g and r) of Malin 1 obtained with the 6.5m Magellan/Clay telescope, detecting structures down to ~ 28 B mag arcsec-2. In order to enhance galaxy features buried in the noise, we use ...

    • Discovery of soft and hard X-ray time lags in low-mass AGNs 

      Mallick, L.; Wilkins, Daniel Richard; Alston, William; Markowitz, Alex; Marco, Barbara de; Parker, Michael L.; Lohfink, Anne M.; Stalin, Chelliah Subramonian (Oxford University Press, 2021-03-05)
      Article
      Accés obert
      The scaling relations between the black hole (BH) mass and soft lag properties for both active galactic nuclei (AGNs) and BH X-ray binaries (BHXRBs) suggest the same underlying physical mechanism at work in accreting BH ...

    • Equivalence of Boltzmann and moment equations 

      Cubarsí Morera, Rafael (2010-10-28)
      Article
      Accés obert
      The closure problem for the stellar hydrodynamic equations is studied by describing the family of phase space density functions, for which the collisionless Boltzmann equation is strictly equivalent to a finite subset of ...

    • Expectations for the high-energy neutrino detection from starburst galaxies with KM3NeT/ARCA 

      Ageron, M.; Aiello, S; Albert, Arthur; Alshamsi, Mohammed; Alves Garre, Sergio; Aly, Zineb; Ambrosone, Antonio; Ameli, F; André, Michel; Androulakis, Giorgos; Anghinolfi, Marco; Anguita, M. (arXiv, 2021)
      Text en actes de congrés
      Accés obert
      Star-forming galaxies (SFGs) and starburst galaxies (SBGs) are extragalactic sources which could produce high-energy neutrinos. In principle, they could play a rather important role for explaining at least a sizeable part ...

    • Formation of asymmetric arms in barred galaxies 

      Sánchez Martín, Patricia; García Gómez, Carles; Masdemont Soler, Josep; Romero Gómez, Merce (Oxford University Press, 2023-04-01)
      Article
      Accés obert
      We establish a dynamical mechanism to explain the origin of the asymmetry between the arms observed in some barred disc galaxies, where one of the two arms emanating from the bar ends is very well defined, while the second ...

    • From manifolds to Lagrangian coherent structures in galactic bar models 

      Sánchez Martín, Patricia; Masdemont Soler, Josep; Romero Gómez, Merce (EDP Sciences, 2018-10-16)
      Article
      Accés obert
      We study the dynamics near the unstable Lagrangian points in galactic bar models using dynamical system tools in order to determine the global morphology of a barred galaxy. We aim at the case of non-autonomous models, in ...

    • Hu 1-2: A metal-poor bipolar planetary nebula with fast collimated outflows 

      Fang, X.; Guerrero, M.A.; Miranda, L.F.; Riera Mora, M. Ángeles; Velázquez, P.F.; Raga, A.C. (2015-10-27)
      Article
      Accés obert
      © 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. We present narrow-band optical and near-IR imaging and optical long-slit spectroscopic observations of Hu 1-2, a Galactic ...

    • Hunting for open clusters in Gaia EDR3: 628 new open clusters found with OCfinder 

      Castro Ginard, Alfred; Jordi Nebot, Carme; Luri Carrascoso, Xavier; Cantat Gaudin, Tristan; Carrasco Martínez, Josep Manel; Casamiquela Floriach, Laia; Anders, Friedrich; Balaguer Núñez, Lola; Badia Sala, Rosa Maria (EDP Sciences, 2022-05)
      Article
      Accés obert
      Context. The improvements in the precision of the published data in Gaia EDR3 with respect to Gaia DR2, particularly for parallaxes and proper motions, offer the opportunity to increase the number of known open clusters ...

    • Indirect dark matter searches with neutrinos from the Galactic Centre region with the ANTARES and KM3NeT telescopes 

      Ageron, M.; Aiello, S; Aublin, J.; Alshamsi, Mohammed; Alves Garre, Sergio; André, Michel; Anghinolfi, Marco; Anton, Gisela; Ardid Ramírez, Miguel; Albert, Arthur; Belhorma, Bouchra; Bendahman, Meriem; Bertin, Vincent; Bissinger, Matthias; Boumaaza, Jihad (arXiv, 2021)
      Text en actes de congrés
      Accés obert
      An anomalous flux of neutrinos produced in hypothetical annihilations or decays of dark matter inside a source would produce a signal observable with neutrino telescopes. As suggested by observations, a conspicuous amount ...

    • Is the metallicity of their host galaxies a good measure of the metallicity of Type Ia supernovae? 

      Bravo Guil, Eduardo; Badenes Montoliu, Carles (2011-06)
      Article
      Accés obert
      The efficient use of Type Ia supernovae (SNIa) for cosmological studies requires knowledge of any parameter that can affect their luminosity in either systematic or statistical ways. Observational samples of SNIa commonly ...

    • Mass-loss and composition of wind ejecta in type I X-ray bursts 

      Herrera, Yago; Sala Cladellas, Glòria; José Pont, Jordi (EDP Sciences, 2023-10-17)
      Article
      Accés obert
      Context. X-Ray bursts (XRBs) are powerful thermonuclear events on the surface of accreting neutron stars (NSs) where nucleosynthesis of intermediate-mass elements occurs. The high surface gravity of an NS prevents the ...

    • Primordial black holes capture by stars and induced collapse to low-mass stellar black holes 

      Oncins Marco, Gerard; Miralda Escudé, Jordi; Gutiérrez Cabello, Jordi; Gil Pons, Pilar (Oxford University Press, 2022-10-04)
      Article
      Accés obert
      Primordial black holes in the asteroid-mass window, which might constitute all the dark matter, can be captured by stars when they traverse them at low enough velocity. After being placed on a bound orbit during star ...

    • Rings and spirals in barred galaxies III. Further comparisons and links to observations 

      Masdemont Soler, Josep; Bosma, A.; Romero Gómez, Mercè; Athanassoula, Evangelie (2010)
      Article
      Accés restringit per política de l'editorial
      In a series of papers, we propose a theory to explain the formation and properties of rings and spirals in barred galaxies. The building blocks of these structures are orbits guided by the manifolds emanating from the ...

    • Short-timescale X-ray spectral variability in the Seyfert 1 galaxy NGC 3783 

      Costanzo, Danilo; Dadina, M.; Vignali, Cristian; Marco, Barbara de; Cappi, Massimo; Petrucci, P.O.; Bianchi, Stefano; Kriss, G.A.; Kaastra, J.S.; Mehdipour, M.; Matzeu, G.A. (EDP Sciences, 2022-03-01)
      Article
      Accés obert
      Aims. We report on the X-ray time-resolved spectral analysis of XMM-Newton observations of NGC 3783. Our main goal is to detect transient features in the Fe K line complex in order to study the dynamics of the innermost ...

    • Supermassive black hole winds in X-rays: SUBWAYS: I. Ultra-fast outflows in quasars beyond the local Universe 

      Matzeu, G.A.; Brusa, Marcella; Lanzuisi, Giorgio; Dadina, M.; Bianchi, Stefano; Kriss, G.A.; Mehdipour, M.; Nardini, Emanuele; Chartas, George; Middei, Riccardo; Piconcelli, Enrico; Marco, Barbara de (EDP Sciences, 2023-02-01)
      Article
      Accés obert
      We present a new X-ray spectroscopic study of 22 luminous (2 × 1045 ¿ Lbol/erg s-1 ¿ 2 × 1046) active galactic nuclei (AGNs) at intermediate redshifts (0.1 ¿ z ¿ 0.4), as part of the SUpermassive Black hole Winds in the ...

    • Supermassive black hole winds in X-rays: SUBWAYS: II. HST UV spectroscopy of winds at intermediate redshifts 

      Mehdipour, M.; Kriss, G.A.; Brusa, Marcella; Matzeu, G.A.; Gaspari, Massimo; Kraemer, Steve; Mathur, Smita; Behar, Ehud; Bianchi, Stefano; Cappi, Massimo; Chartas, George; Marco, Barbara de (EDP Sciences, 2023-02-01)
      Article
      Accés obert
      We present a UV spectroscopic study of ionized outflows in 21 active galactic nuclei (AGN), observed with the Hubble Space Telescope (HST). The targets of the Supermassive Black Hole Winds in X-rays (SUBWAYS) sample were ...

    • Tails and bridges in the parabolic restricted three-body problem 

      Barrabés Vera, Esther; Cors Iglesias, Josep Maria; García Taberner, Laura; Ollé Torner, Mercè (2017-01-01)
      Article
      Accés obert
      After a close encounter of two galaxies, bridges and tails can be seen between or around them. A bridge would be a spiral arm between a galaxy and its companion, whereas a tail would correspond to a long and curving set ...

    • The lively accretion disc in NGC 2992-II. The 2019/2021 X-ray monitoring campaigns 

      Middei, Riccardo; Marinucci, Andrea; Braito, V.; Marco, Barbara de; Luminari, Alfredo; Matt, Giorgio; Nardini, Emanuele; Perri, Matteo; Reeves, J. N.; Vagnetti, Fausto (Oxford University Press, 2022-08-01)
      Article
      Accés obert
      We report on the short- and long-term X-ray properties of the bright nearby Seyfert 2 galaxy NGC 2992, which was extensively observed with Swift, XMM–Newton, and NuSTAR. Swift targeted the source more than 100 times between ...

    • The lively accretion disk in NGC 2992. III. Tentative evidence of rapid ultrafast outflow variability 

      Luminari, Alfredo; Marinucci, Andrea; Bianchi, Stefano; Marco, Barbara de; Feruglio, Chiara; Matt, Giorgio; Middei, Riccardo; Nardini, Emanuele; Piconcelli, Enrico; Puccetti, Simonetta; Tombesi, Francesco (Institute of Physics (IOP), 2023-06-01)
      Article
      Accés obert
      We report on the 2019 XMM-Newton+NuSTAR monitoring campaign of the Seyfert galaxy NGC 2992, observed at one of its highest flux levels in the X-rays. The time-averaged spectra of the two XMM-Newton orbits show ultrafast ...