Essays about: "Upper luminosity limit"

Found 3 essays containing the words Upper luminosity limit.

  1. 1. What limits the luminosity of red supergiants?

    University essay from Lunds universitet/Astrofysik; Lunds universitet/Fysiska institutionen

    Author : Eric Svensson; [2023]
    Keywords : Stellar evolution; Red supergiants; Red giants; Luminosity; Binary stars; Binary star systems; Binary star interactions; Binary stellar evolution; Humphreys-Davidson limit; Upper luminosity limit; BSE; Population synthesis; Simulations; M31; LMC; SMC; Metallicity; Mass transfer; Merging; Physics and Astronomy;

    Abstract : The observed upper limit of the luminosity of red supergiants, often called the Humphreys-Davidson limit, has recently been shown to be independent of metallicity and to not be explainable by single star evolution – findings that both contradict established ideas of the origins of the limit. It is now known that the vast majority of stars with sufficient mass to possibly evolve into red supergiants above the limit interact with companion stars at some point during their lives. READ MORE

  3. 2. Constraining the Higgs width in Higgs production associated with a top quark pair

    University essay from Lunds universitet/Fysiska institutionen; Lunds universitet/Teoretisk partikelfysik - Geonomgår omorganisation

    Author : Benjamin Dahlén; [2023]
    Keywords : Higgs; width; cross section; on-shell; off-shell; invariant mass; Standard model; upper bound; Physics and Astronomy;

    Abstract : In this thesis we study the width of the Higgs boson in the process pp → t ̄t 4l at LO using MadGraph5_aMC@NLO to generate the events. The contributions including the Higgs signal, continuum background and interference were considered in order to calculate the expected number of events in a broad range of four-lepton invariant masses. READ MORE

  4. 3. Estimating Properties of a Young Pulsar through X-ray Observations - An Investigation of Parameter Dependence

    University essay from KTH/Fysik

    Author : Lurin Ali; [2022]
    Keywords : Pulsar; Neutron star; Supernova;

    Abstract : Studying the properties of newborn neutron stars is a complicated matter since they cannot be directly observed. Neutron stars are born when some massive stars go supernova (SN), where the expelled material from the explosion goes on to shield the young neutron star from our view by absorbing its radiation. READ MORE