CORE COLLAPSE SUPERNOVAE SNE ARISE FROM MASSIVE STARS, WITH INITIAL MASS GREATER THAN ABOUT 8 SOLAR MASSES. THESE STARS LOSE A SIGNIFICANT AMOUNT OF MASS IN THE...

CORE COLLAPSE SUPERNOVAE SNE ARISE FROM MASSIVE STARS, WITH INITIAL MASS GREATER THAN ABOUT 8 SOLAR MASSES. THESE STARS LOSE A SIGNIFICANT AMOUNT OF MASS IN THE FORM OF STELLAR WINDS, BEFORE THEY EXPLODE AS SUPERNOVAE. THE RESULTING SHOCK WAVE WILL EXPAND IN THIS CIRCUMSTELLAR MEDIUM CSM CREATED BY THE PROGENITOR STAR, HEATING UP THE MATERIAL TO VERY HIGH TEMPERATURES, THUS RESULTING IN STRONG X RAY EMISSION. IN THIS PROPOSAL WE FOCUS ON THE CLASS OF SNE KNOWN AS TYPE IIN SNE. THESE SNE TEND TO BE SOME OF THE BRIGHTEST KNOWN X RAY SNE, AND HAVE BEEN OBSERVED FOR YEARS OR EVEN DECADES AFTER EXPLOSION. THEIR HIGH LUMINOSITY, IN MANY CASES AT BOTH X RAY AND RADIO WAVELENGTHS, SUGGESTS INTERACTION WITH A DENSE CSM, OFTEN CLOSE TO THE STAR. HOWEVER, THEIR NATURE, ORIGINS AND PROGENITORS ARE STILL A MYSTERY. WE WILL DOWNLOAD, REDUCE AND ANALYSE ALL AVAILABLE X RAY DATA ON TYPE IINS. THIS INCLUDES OVER 4 MILLION SECONDS OF X RAY DATA AVAILABLE CURRENTLY IN THE ARCHIVES, PLUS MORE THAT WILL

BECOME AVAILABLE DURING THE COURSE OF THIS AWARD. ANALYSIS OF THE X RAY LIGHTCURVES AND SPECTRA OF SNE CAN PROVIDE INFORMATION ON THE SHOCK TEMPERATURES, VELOCITIES AND DENSITIES. THE X RAY DIAGNOSTICS CAN BE USED TO STUDY THE EVOLUTION OF THE SNE, DETERMINE THE ABUNDANCES, AND EXCAVATE THE STRUCTURE OF THE AMBIENT MEDIUM. THE DENSITY STRUCTURE OF THE SURROUNDING MEDIUM CAN BE RELATED TO THE STELLAR MASS LOSS, AND THUS BE USED TO PROBE THE STELLAR PROGENITOR. THE FIRST GOAL OF THIS PROJECT IS TO PRODUCE A HOMOGENEOUS SET OF X RAY LIGHTCURVES OF TYPE IINS IN TWO SPECIFIC ENERGY BANDS, THE 0.4 2.4 KEV BAND COMMON TO ALMOST ALL X RAY SATELLITES AS WELL AS THE 2.4 10 KEV BAND PROVIDED BY THE TWO CURRENT MAJOR X RAY MISSIONS, CHANDRA AND XMM NEWTON . THE SLOPE OF THE LIGHT CURVE CAN BE USED AS AN INITIAL GUIDE TO PROVIDE CLUES TO THE DENSITY STRUCTURE OF THE AMBIENT MEDIUM INTO WHICH THE SN IS EXPANDING. FOR THOSE SNE WHICH HAVE SUFFICIENT SPECTRA AVAILABLE WHICH ARE RAPIDLY GROWING IN NUMBER, WE WILL FOLLOW UP WITH CAREFULLY CONSTRUCTED NUMERICAL HYDRODYNAMIC SIMULATIONS, AND COMPUTATION OF THE SIMULATED X RAY EMISSION USING NON EQUILIBRIUM IONIZATION CALCULATIONS. COMBINED WITH OBSERVATIONS AT OTHER WAVELENGTHS, WHICH ARE PLENTIFUL, THIS CAN BE USED TO INVESTIGATE THE NATURE AND EVOLUTION OF THE RESULTING SN SHOCK WAVE, THE DENSITY STRUCTURE OF THE SURROUNDING CIRCUMSTELLAR MEDIUM, AND THEREBY THE NATURE OF THE PROGENITOR STAR. MANY RECENT OPTICAL AND IR OBSERVATIONS SUGGEST THAT THE PROGENITOR STARS OF TYPE IIN SNE MAY UNDERGO AN `OUTBURST, WITH ENHANCED MASS LOSS RATES, TENS TO HUNDREDS OF YEARS BEFORE EXPLOSION AS SNE. WE WILL SEARCH THE X RAY DATA FOR CLUES TO THE EXISTENCE AND PROPERTIES OF SUCH OUTBURSTS. BESIDES ENHANCING OUR UNDERSTANDING OF TYPE IIN SUPERNOVAE, THE PROJECT WILL HAVE MORE FAR REACHING EFFECTS. 1. INVESTIGATION OF SHOCK WAVE PROPAGATION IN INHOMOGENEOUS MEDIA. 2. GLIMPSES INTO THE LAST STAGES OF MASSIVE STAR EVOLUTION. 3. A DEEPER UNDERSTANDING OF MASS LOSS FROM MASSIVE STAR PROGENITORS ON THEIR WAY TO BECOMING SNE AND 4 A PEEK INTO THE ENVIRONMENTS IN WHICH TYPE IIN SUPERNOVAE ARE FOUND. A BY PRODUCT OF OUR INVESTIGATION WILL BE A CONSISTENT AND RIGOROUSLY DERIVED DATABASE OF TYPE IIN SN SPECTRA AND LIGHTCURVES, WHICH WE WILL MAKE AVAILABLE ON OUR WEBSITE TO ALL ASTRONOMERS.
Solicitation ID/Procurement Identifier: NNX14AR63G
Ultimate Completion Date: Fri Aug 28 17:00:00 GMT 2020