Browsing by Author "Kobayashi, Chiaki"

Now showing items 1-20 of 102

    • The 6dF Galaxy Survey: : Stellar Population Trends Across and Through the Fundamental Plane 

      Springob, Christopher M.; Magoulas, Christina; Proctor, Rob; Colless, Matthew; Jones, D. Heath; Kobayashi, Chiaki; Campbell, Lachlan; Lucey, John; Mould, Jeremy (2012-03-11)
      We present results from an analysis of stellar population parameters for 7132 galaxies in the 6dFGS Fundamental Plane (FP) sample. We bin the galaxies along the axes, $v_1$, $v_2$, and $v_3$, of the tri-variate Gaussian ...

    • The absence of an environmental dependence in the mass-metallicity relation at z = 2 

      Kacprzak, Glenn G.; Yuan, Tiantian; Nanayakkara, Themiya; Kobayashi, Chiaki; Tran, Kim V. Y. H.; Kewley, Lisa J.; Glazebrook, Karl; Spitler, Lee; Taylor, Philip; Cowley, Michael; Labbe, Ivo; Straatman, Caroline; Tomczak, Adam (2015-04-02)
      We investigate the environmental dependence of the mass-metallicity relation at z = 2 with MOSFIRE/Keck as part of the ZFIRE survey. Here, we present the chemical abundance of a Virgo-like progenitor at z = 2.095 that has ...

    • 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 ...

    • Astraeus V: the emergence and evolution of metallicity scaling relations during the epoch of reionization 

      Ucci, Graziano; Dayal, Pratika; Hutter, Anne; Kobayashi, Chiaki; Gottloeber, Stefan; Yepes, Gustavo; Hunt, Leslie; Legrand, Laurent; Tortora, Crescenzo (2023-01-30)
      In this work, we have implemented a detailed physical model of galaxy chemical enrichment into the ASTRAEUS (seminumerical rAdiative tranSfer coupling of galaxy formaTion and Reionization in N-body dark matter simUlationS) ...

    • Astrophysics: : Elemental abundances across cosmic time 

      Kobayashi, Chiaki (2016-12-08)
      The chemical composition of a massive galaxy in the early Universe reveals an extremely short period of star formation. This result could challenge our ideas about the evolution of galaxies and of the Universe itself.

    • Azimuthal variations of gas-phase oxygen abundance in NGC 2997 

      Ho, I-Ting; Meidt, Sharon E.; Kudritzki, Rolf-Peter; Groves, Brent A.; Seibert, Mark; Madore, Barry F.; Schinnerer, Eva; Rich, Jeffrey A.; Kobayashi, Chiaki; Kewley, Lisa J. (2018-10-15)
      The azimuthal variation of the HII region oxygen abundance in spiral galaxies is a key observable for understanding how quickly oxygen produced by massive stars can be dispersed within the surrounding interstellar medium. ...

    • Can Neutron Star Mergers Alone Explain the r-process Enrichment of the Milky Way? 

      Kobayashi, Chiaki; Mandel, Ilya; Belczynski, Krzysztof; Goriely, Stephane; Janka, Thomas H.; Just, Oliver; Ruiter, Ashley J.; Vanbeveren, Dany; Kruckow, Matthias U.; Briel, Max M.; Eldridge, Jan J.; Stanway, Elizabeth (2023-01-30)
      Comparing Galactic chemical evolution models to the observed elemental abundances in the Milky Way, we show that neutron star mergers can be a leading r-process site only if at low metallicities such mergers have very short ...

    • A Catalog of Potential Post–Common Envelope Binaries 

      Kruckow, Matthias U.; Neunteufel, Patrick G.; Stefano, Rosanne Di; Gao, Yan; Kobayashi, Chiaki (2021-10-20)
      We present a catalogue containing 839 candidate post common envelope systems. Common envelope evolution is very important in stellar astrophysics, particularly in the context of very compact and short-period binaries, ...

    • Catching Element Formation In The Act 

      Fryer, Chris L.; Timmes, Frank; Hungerford, Aimee L.; Couture, Aaron; Adams, Fred; Aoki, Wako; Arcones, Almudena; Arnett, David; Auchettl, Katie; Avila, Melina; Badenes, Carles; Baron, Eddie; Bauswein, Andreas; Beacom, John; Blackmon, Jeff; Blondin, Stephane; Bloser, Peter; Boggs, Steve; Boss, Alan; Brandt, Terri; Bravo, Eduardo; Brown, Ed; Brown, Peter; Budtz-Jorgensen, Steve Bruenn Carl; Burns, Eric; Calder, Alan; Caputo, Regina; Champagne, Art; Chevalier, Roger; Chieffi, Alessandro; Chipps, Kelly; Cinabro, David; Clarkson, Ondrea; Clayton, Don; Coc, Alain; Connolly, Devin; Conroy, Charlie; Cote, Benoit; Couch, Sean; Dauphas, Nicolas; deBoer, Richard James; Deibel, Catherine; Denisenkov, Pavel; Desch, Steve; Dessart, Luc; Diehl, Roland; Doherty, Carolyn; Dominguez, Inma; Dong, Subo; Dwarkadas, Vikram; Fan, Doreen; Fields, Brian; Fields, Carl; Filippenko, Alex; Fisher, Robert; Foucart, Francois; Fransson, Claes; Frohlich, Carla; Fuller, George; Gibson, Brad; Giryanskaya, Viktoriya; Gorres, Joachim; Goriely, Stephane; Grebenev, Sergei; Grefenstette, Brian; Grohs, Evan; Guillochon, James; Harpole, Alice; Harris, Chelsea; Harris, J. Austin; Harrison, Fiona; Hartmann, Dieter; Hashimoto, Masa-aki; Heger, Alexander; Hernanz, Margarita; Herwig, Falk; Hirschi, Raphael; Hix, Raphael William; Hoflich, Peter; Hoffman, Robert; Holcomb, Cole; Hsiao, Eric; Iliadis, Christian; Janiuk, Agnieszka; Janka, Thomas; Jerkstrand, Anders; Johns, Lucas; Jones, Samuel; Jose, Jordi; Kajino, Toshitaka; Karakas, Amanda; Karpov, Platon; Kasen, Dan; Kierans, Carolyn; Kippen, Marc; Korobkin, Oleg; Kobayashi, Chiaki; Kozma, Cecilia; Krot, Saha; Kumar, Pawan; Kuvvetli, Irfan; Laird, Alison; Laming, Martin; Larsson, Josefin; Lattanzio, John; Lattimer, James; Leising, Mark; Lennarz, Annika; Lentz, Eric; Limongi, Marco; Lippuner, Jonas; Livne, Eli; Lloyd-Ronning, Nicole; Longland, Richard; Lopez, Laura A.; Lugaro, Maria; Lutovinov, Alexander; Madsen, Kristin; Malone, Chris; Matteucci, Francesca; McEnery, Julie; Meisel, Zach; Messer, Bronson; Metzger, Brian; Meyer, Bradley; Meynet, Georges; Mezzacappa, Anthony; Miller, Jonah; Miller, Richard; Milne, Peter; Misch, Wendell; Mitchell, Lee; Mosta, Philipp; Motizuki, Yuko; Muller, Bernhard; Mumpower, Matthew; Murphy, Jeremiah; Nagataki, Shigehiro; Nakar, Ehud; Nomoto, Ken'ichi; Nugent, Peter; Nunes, Filomena; O'Shea, Brian; Oberlack, Uwe; Pain, Steven; Parker, Lucas; Perego, Albino; Pignatari, Marco; Pinedo, Gabriel Martinez; Plewa, Tomasz; Poznanski, Dovi; Priedhorsky, William; Pritychenko, Boris; Radice, David; Ramirez-Ruiz, Enrico; Rauscher, Thomas; Reddy, Sanjay; Rehm, Ernst; Reifarth, Rene; Richman, Debra; Ricker, Paul; Rijal, Nabin; Roberts, Luke; Ropke, Friedrich; Rosswog, Stephan; Ruiter, Ashley J.; Ruiz, Chris; Savin, Daniel Wolf; Schatz, Hendrik; Schneider, Dieter; Schwab, Josiah; Seitenzahl, Ivo; Shen, Ken; Siegert, Thomas; Sim, Stuart; Smith, David; Smith, Karl; Smith, Michael; Sollerman, Jesper; Sprouse, Trevor; Spyrou, Artemis; Starrfield, Sumner; Steiner, Andrew; Strong, Andrew W.; Sukhbold, Tuguldur; Suntzeff, Nick; Surman, Rebecca; Tanimori, Toru; The, Lih-Sin; Thielemann, Friedrich-Karl; Tolstov, Alexey; Tominaga, Nozomu; Tomsick, John; Townsley, Dean; Tsintari, Pelagia; Tsygankov, Sergey; Vartanyan, David; Venters, Tonia; Vestrand, Tom; Vink, Jacco; Waldman, Roni; Wang, Lifang; Wang, Xilu; Warren, MacKenzie; West, Christopher; Wheeler, J. Craig; Wiescher, Michael; Winkler, Christoph; Winter, Lisa; Wolf, Bill; Woolf, Richard; Woosley, Stan; Wu, Jin; Wrede, Chris; Yamada, Shoichi; Young, Patrick; Zegers, Remco; Zingale, Michael; Zwart, Simon Portegies (2019-03-31)
      Gamma-ray astronomy explores the most energetic photons in nature to address some of the most pressing puzzles in contemporary astrophysics. It encompasses a wide range of objects and phenomena: stars, supernovae, novae, ...

    • Chemical enrichment in the carbon-enhanced damped Ly α system by population III supernovae 

      Kobayashi, Chiaki; Tominaga, Nozomu; Nomoto, Ken'ichi (2011-04-01)
      We show that the recently observed elemental abundance pattern of the carbon-rich metal-poor damped Ly alpha (DLA) system is in excellent agreement with the nucleosynthesis yields of faint core-collapse supernovae of ...

    • Chemical Evolution with Radial Mixing Redux: a detailed model for formation and evolution of the Milky Way 

      Chen, Boquan; Hayden, Michael R.; Sharma, Sanjib; Bland-Hawthorn, Joss; Kobayashi, Chiaki; Karakas, Amanda I. (2023-08-31)
      We present a multi-zone galactic chemical evolution (GCE) model for the Milky Way that takes the most recently updated yields of major nucleosynthesis channels into account. It incorporates physical processes commonly found ...

    • Chemo-Dynamical Evolution of Galaxies 

      Kobayashi, Chiaki; Taylor, Philip (Springer Nature, 2023-02-17)
      Stars are fossils that retain the history of their host galaxies. Elements heavier than helium are created inside stars and are ejected when they die. From the spatial distribution of elements in galaxies, it is therefore ...

    • Chemo-dynamical Simulations and Galactic Archaeology 

      Kobayashi, Chiaki (American Institute of Physics (AIP), 2010)
      We predict the frequency distribution of elemental abundance ratios from Carbon to Zinc as a functions of time and location, which can be directly compared with the next generation of the galactic archeology project such ...

    • Chemo-dynamical simulations of galaxies 

      Kobayashi, Chiaki (Cambridge University Press, 2010)
      We simulate the formation and evolution of galaxies with a self-consistent 3D hydrodynamical model including star formation, supernova feedback, and chemical enrichment. Hypernova feedback plays an essential role not only ...

    • Chemodynamical simulations of the Milky Way galaxy 

      Kobayashi, Chiaki; Nakasato, Naohito (2011-03-01)
      We present chemodynamical simulations of a Milky-Way-type galaxy using a self-consistent hydrodynamical code that includes supernova feedback and chemical enrichment, and predict the spatial distribution of elements from ...

    • Chemodynamical simulations of the Milky Way Galaxy 

      Kobayashi, Chiaki (Cambridge University Press, 2009)
      We simulate the chemodynamical evolution of the Milky Way Galaxy, including the nucleosynthesis yields of hypernovae and a new progenitor model for Type la Supernovae (SNe la). In our nucleosynthesis yields of core-collapse ...

    • Chemodynamical Simulations with Variable IMF 

      Kobayashi, Chiaki (American Institute of Physics (AIP), 2010)
      Using self-consistent chemodynamical simulations including star formation, supernova feedback, and chemical enrichment, I show the dependence of the initial mass function (IMF) on cosmic star formation and chemical enrichment ...

    • The COMBS Survey -- III. The Chemodynamical Origins of Metal-Poor Bulge Stars 

      Lucey, Madeline; Hawkins, Keith; Ness, Melissa; Nelson, Tyler; Debattista, Victor P.; Luna, Alice; Bensby, Thomas; Freeman, Kenneth C.; Kobayashi, Chiaki (2022-01-01)
      The characteristics of the stellar populations in the Galactic Bulge inform and constrain the Milky Way's formation and evolution. The metal-poor population is particularly important in light of cosmological simulations, ...

    • The COMBS survey I : Chemical Origins of Metal-Poor Stars in the Galactic Bulge 

      Lucey, Madeline; Hawkins, Keith; Ness, Melissa; Asplund, Martin; Bensby, Thomas; Casagrande, Luca; Feltzing, Sofia; Freeman, Kenneth C.; Kobayashi, Chiaki; Marino, Anna F. (2019-09-01)
      Chemistry and kinematic studies can determine the origins of stellar population across the Milky Way. The metallicity distribution function of the bulge indicates that it comprises multiple populations, the more metal-poor ...

    • The COMBS Survey II: Distinguishing the Metal-Poor Bulge from the Halo Interlopers 

      Lucey, Madeline; Hawkins, Keith; Ness, Melissa; Debattista, Victor P.; Luna, Alice; Asplund, Martin; Bensby, Thomas; Casagrande, Luca; Feltzing, Sofia; Freeman, Kenneth C.; Kobayashi, Chiaki; Marino, Anna F. (2021-03-01)
      The metal-poor stars in the bulge are important relics of the Milky Way's formation history, as simulations predict that they are some of the oldest stars in the Galaxy. In order to determine if they are truly ancient ...