Browsing by Author "Centre for Astrophysics Research"

Now showing items 138-157 of 3208

    • Alpha-clustering and the stellar nucleosynthesis of carbon 

      Oberhummer, H.; Krauss, H.; Grun, K.; Rauscher, T.; Abele, H.; Mohr, P.; Staudt, G. (1994-09)
      The astrophysical S-factor and reaction rates for the triple-alpha process are calculated in the direct-capture model. It is shown that the stellar carbon production is extremely sensitive to small variations in the N-N ...

    • alpha-induced cross sections of Cd-106 for the astrophysical p process 

      Gyurky, Gy.; Kiss, G. G.; Elekes, Z.; Fulop, Zs.; Somorjai, E.; Palumbo, A.; Gorres, J.; Lee, H. Y.; Rapp, W.; Wiescher, M.; Ozkan, N.; Guray, R. T.; Efe, G.; Rauscher, T. (2006-08)
      The Cd-106(alpha,gamma)Sn-110 reaction cross section has been measured in the energy range of the Gamow window for the astrophysical p-process scenario. The cross sections for Cd-106(alpha,n)Sn-109 and for Cd-106(alpha,p)In-109 ...

    • Alpha-induced reaction cross section measurements on Eu-151 for the astrophysical gamma-process 

      Gyuerky, Gy.; Elekes, Z.; Farkas, J.; Fueloep, Zs.; Halasz, Z.; Kiss, G. G.; Somorjai, E.; Szuecs, T.; Guray, R. T.; Ozkan, N.; Yalcin, C.; Rauscher, T. (2010-11)
      In order to extend the experimental database relevant for the astrophysical gamma-process towards the unexplored heavier mass region, the cross sections of the Eu-151(alpha, gamma)Tb-155 and Eu-151 (alpha, n)Tb-154 reactions ...

    • Alpha-induced reactions for the astrophysical p-process : the case of (151)Eu 

      Gyuerky, G. Y.; Elekes, Z.; Farkas, J.; Fueloep, Z. S.; Kiss, G. G.; Somorjai, E.; Szuecs, T.; Guray, R. T.; Ozkan, N.; Yalcin, C.; Rauscher, T. (IOP Publishing Ltd., 2010)
      The cross sections of (151)Eu(alpha, gamma)(155)Tb and (151)Eu(alpha,n)(154)Tb reactions have been measured with the activation method. Some aspects of the measurement are presented here to illustrate the requirements of ...

    • alpha-nucleus potentials and photon-induced nucleosynthesis 

      Galaviz, D.; Babilon, M.; Fulop, Zs.; Gyurky, Gy.; Hillier, R.; Mate, Z.; Mohr, P.; Rauscher, T.; Somorjai, E.; Zilges, A.; Zolnai, L. (2003-05-05)
      New data for the Sn-112,Sn-12 4(alpha,alpha) (112,124) Sn reaction have been measured and are presently analyzed. Results of the Sn-112 circle times alpha potential at the energy Ec.m approximate to 14 MeV are presented. ...

    • The AM Herculis type binary E1405-451 

      Bailey, J.; Axon, D.J.; Hough, J.; Watts, D.J.; Giles, A.B.; Greenhill, J.G. (1983)
      The authors report photometry and polarimetry of the AM Her-type binary E1405-451. For the first time circular polarization has been detected in such an object at wavelengths longer than 1 μm. The light curves and polarization ...

    • Ammonia in the interstellar medium of a starbursting disc at z=2.6 

      Doherty, M. J.; Geach, J. E.; Ivison, R. J.; Menten, K. M.; Jacob, A. M.; Forbrich, J.; Dye, S. (2022-09-23)
      We report the detection of the ground state rotational emission of ammonia, ortho-NH$_3$ $(J_K=1_0\rightarrow0_0)$ in a gravitationally lensed, intrinsically hyperluminous, star-bursting galaxy at $z=2.6$. The integrated ...

    • Analysis of combined radial velocities and activity of BD+20 1790: : evidence supporting the existence of a planetary companion 

      Hernán-Obispo, M.; Tuomi, Mikko; Gálvez-Ortiz, M. C.; Golovin, A.; Barnes, J. R.; Jones, Hugh; Kane, S. R.; Pinfield, D.; Jenkins, J. S.; Petit, P.; Anglada-Escudé, G.; Marsden, S. C.; Catalán, S.; Jeffers, S. V.; Castro, E. de; Cornide, M.; Garcés, A.; Jones, M. I.; Gorlova, N.; Andreev, M. (2015-04-01)
      This paper presents the simultaneous Bayesian analysis of the radial velocity and activity indices for the K5Ve active star BD+20 1790, that was proposed to host a close-in massive planet by Hern\'an-Obispo et al. (2010). ...

    • Analysis of Li-8(alpha, n)B-11 below the Coulomb barrier in the potential model 

      Rauscher, T.; Grun, K.; Krauss, H.; Oberhummer, H.; Kwasniewicz, E. (1992-04)
      The reaction Li-8(alpha, n)B-11 is of interest in inhomogeneous big bang nucleosynthesis. A distorted wave Born approximation calculation employing folding potentials is presented for energies below the Coulomb barrier. ...

    • Analysis of physical processes in eruptive YSOs with near infrared spectra and multi-wavelength light curves 

      Guo, Zhen; Lucas, P. W.; Contreras Pena, Carlos; Smith, L. C.; Morris, C.; Kurtev, R. G.; Borissova, J.; Alonso-García, J.; Minniti, D.; Chené, A. -N.; Kumar, M. S. N.; Garatti, A. Caratti o; Froebrich, D. (2021-03-26)
      The decade-long Vista Variables in the Via Lactea (VVV) survey has detected numerous highly variable young stellar objects (YSOs). We present a study of 61 highly variable VVV YSOs (Delta Ks = 1-5 mag), combining near ...

    • Anatomy of a post-starburst minor merger : A multi-wavelength WFC3 study of NGC 4150 

      Crockett, R.M.; Kaviraj, S.; Silk, J.I.; Whitmore, B.C.; Mutchler, M.; Bond, H.E.; O'Connell, R.W.; Balick, B.; Calzetti, D.; Carollo, C.M.; Disney, M.J.; Dopita, M.A.; Frogel, J.A.; Hall, D.N.B.; Holtzman, J. A.; Kimble, R.A.; McCarthy, P.J.; Paresce, F.; Saha, A.; Trauger, J.T.; Walker, A.R.; Windhorst, R.A.; Young, E.T.; Jeong, H.; Yi, S.K. (2011-02-01)
      We present a spatially resolved near-UV/optical study, using the Wide Field Camera 3 (WFC3) on board the Hubble Space Telescope, of NGC 4150, a sub-L , early-type galaxy (ETG) of around 6 × 10 M , which has been observed ...

    • A and F stars as probes of outer Galactic disc kinematics 

      Harris, A.; Drew, J. E.; Farnhill, H. J.; Monguió, M.; Gebran, M.; Wright, N. J.; Drake, J. J.; Sale, S. E. (2018-04-01)
      Previous studies of the rotation law in the outer Galactic disc have mainly used gas tracers or clump giants. Here, we explore A and F stars as alternatives: these provide a much denser sampling in the outer disc than gas ...

    • The Andromeda Galaxy’s Last Major Merger: Constraints from the survey of Planetary Nebulae 

      Bhattacharya, Souradeep; Arnaboldi, Magda; Gerhard, Ortwin; Caldwell, Nelson; Kobayashi, Chiaki; Hammer, Francois; Yang, Yanbin; Freeman, Kenneth C.; Hartke, Johanna; McConnachie, Alan (The International Astronomical Union, 2023-05-04)
      The Andromeda galaxy (M 31) has experienced a tumultuous merger history as evidenced by the many substructures present in its inner halo. We use planetary nebulae (PNe) as chemodynamic tracers to shed light on the recent ...

    • The Anglo-Australian planet search XXI : a gas-giant planet in a one year orbit and the habitability of gas-giant satellites 

      Tinney, C. G.; Wittenmyer, Robert A.; Butler, R. Paul; Jones, H.R.A.; O'Toole, Simon J.; Bailey, Jeremy A.; Carter, Brad D.; Horner, J. (2011-05-01)
      We have detected the Doppler signature of a gas-giant exoplanet orbiting the star HD 38283, in an eccentric orbit with a period of almost exactly one year (P = 363.2 +/- 1.6 d, m sin i = 0.34 +/- 0.02 M-Jup, e = 0.41 +/- ...

    • The Anglo-Australian Planet Search XXIV: The Frequency of Jupiter Analogs 

      Wittenmyer, Robert A.; Butler, R. Paul; Tinney, C. G.; Horner, Jonathan; Carter, B. D.; Wright, D. J.; Jones, Hugh; Bailey, J.; O'Toole, Simon J. (2016-03-01)
      We present updated simulations of the detectability of Jupiter analogs by the 17-year Anglo-Australian Planet Search. The occurrence rate of Jupiter-like planets that have remained near their formation locations beyond the ...

    • The Anglo-Australian Planet Search XXV : A Candidate Massive Saturn Analog Orbiting HD 30177 

      Wittenmyer, Robert A.; Horner, Jonathan; Mengel, M. W.; Butler, R. P.; Tinney, C. G.; Carter, B. D.; Jones, H. R. A.; Anglada-Escude, G.; Bailey, J.; O'Toole, Simon J. (2017-03-20)
      We report the discovery of a second long-period giant planet orbiting HD 30177, a star previously known to host a massive Jupiter analog (HD 30177b: a=3.8$\pm$0.1 au, m sin $i=9.7\pm$0.5 Mjup). HD 30177c can be regarded ...

    • The Anglo-Australian planet search. XX. A solitary ice-giant planet orbiting HD 102365 

      Tinney, C. G.; Butler, R. Paul; Jones, H.R.A.; Wittenmyer, Robert A.; O'Toole, Simon; Bailey, Jeremy; Carter, Brad D. (2011)
      We present 12 years of precision Doppler data for the very nearby G3 star HD 102365, which reveals the presence of a Neptune-like planet with a 16.0 M-Earth minimum mass in a 122.1 day orbit. Very few "Super Earth" planets ...

    • The Anglo-Australian planet search. XXII : Two new multi-planet systems 

      Wittenmyer, Robert A.; Horner, J.; Tuomi, Mikko; Salter, G. S.; Tinney, C.G.; Butler, R. P.; Jones, H.R.A.; O'Toole, S. J.; Bailey, J.; Carter, B. D.; Jenkins, J. S.; Zhang, Z.; Vogt, S. S.; Rivera, Eugenio J. (2012-07-10)
      We report the detection of two new planets from the Anglo-Australian Planet Search. These planets orbit two stars each previously known to host one planet. The new planet orbiting HD 142 has a period of 6005 +/- 427 days, ...

    • The Anglo-Australian planet search. XXIII. Two new jupiter analogs 

      Wittenmyer, Robert A.; Horner, Jonathan; Tinney, C. G.; Butler, R. P.; Jones, H. R A; Salter, G. S.; Carter, B. D.; Koch, F. Elliott; O'Toole, S. J.; Bailey, J.; Wright, D.; Tuomi, Mikko (2014-03-10)
      We report the discovery of two long-period giant planets from the Anglo-Australian Planet Search. HD 154857c is in a multiple-planet system, while HD 114613b appears to be solitary. HD 114613b has an orbital period P = ...

    • The angular clustering of infrared-selected obscured and unobscured quasars 

      DiPompeo, M. A.; Myers, A. D.; Hickox, R. C.; Geach, J. E.; Hainline, K. N. (2014-08-21)
      Recent studies of luminous infrared-selected active galactic nuclei (AGN) suggest that the reddest, most obscured objects display a higher angular clustering amplitude, and thus reside in higher mass darkmatter haloes. ...