Finding the First Cosmic Explosionswith JWST

Daniel WhalenMcWilliams Fellow Carnegie Mellon University

My Collaborators

• Chris Fryer (LANL)

• Daniel Holz (LANL)

• Massimo Stiavelli (STSci)

• Alexander Heger (University of Minnesota)

• Candace Joggerst (LANL)

• Catherine Lovekin (LANL)

• Lucy Frey (LANL)

~ 200 pc

105 - 106 Msol halos at z ~ 20

Birthplaces ofPrimordial Stars

Properties of the First Stars

• thought to be very massive (25 - 500 solar masses) due to inefficient H2 cooling

• form in isolation (either one per halo or in binaries)

• Tsurface ~ 100,000 K

• extremely luminous sources of ionizing and LW photons (> 1050 photons s-1)

• 2 - 3 Myr lifetimes

• no known mechanisms for mass loss -- no line-driven winds

Photoevaporation of a Halo by a Pop III StarWhalen, Abel & Norman 2004, ApJ, 610, 14

Primordial Ionization Front InstabilitiesWhalen & Norman 2008, ApJ, 675, 644

Final Fates of the First Stars Heger & Woosley 2002, ApJ 567, 532

Mixing & Fallback in 15 – 40 Msol Pop III SNe

Joggerst, .., Whalen, et al 2010ApJ 709, 11

Mixing in 150 –250 Msol Pop IIIPI SNe

Joggerst & Whalen 2011,ApJ, 728, 129

LANL Pop III Supernova Light Curve EffortWhalen et al. ApJ 2010a,b,c in prep

• begin with 1D Pop III 15 – 40 Msol CC SN and 150 – 250 Msol

PI SN blast profiles

• evolve these explosions through breakout from the surface of the star out to 6 mo (CC SNe) or 3 yr (PI SNe) in the LANL radiation hydro code RAGE (Radiation Adaptive Grid Eulerian)

• post-process RAGE profiles with the LANL SPECTRUM code to compute LCs and spectra

• perform MC Monte Carlo models of strong GL of z ~ 20 SNe to calculate flux boosts

• convolve boosted spectra with models for absorption by the Lyman alpha forest and JWST instrument response to determine detection thresholds in redshift

Post Processing Includes Detailed LANL Opacities

atomic levels are assumed to be in equilibrium: an approximation

Our Grid of Pop III SN LightCurve Models

• 150, 175, 200, 225, and 250 Msol PI SN explosions, blue and red progenitors, in modest winds and in diffuse relic H II regions (18 models)

• 15, 25, and 40 Msol CC SN explosions, red and blue progenitors, three explosion energies in relic H II regions only

• red and blue progenitors span the range of expected stellar structures for Pop III stars

• core-collapse KEPLER blast profiles are evolved in 2D in the CASTRO AMR code first up to shock breakout to capture internal mixing—these profiles are then spherically averaged and evolved in RAGE to compute LCs

u150

u200

u175

u225

PISN Shock Breakout

• X-rays (< 1 keV)

• transient (a few hours in the local frame)

Spectra atBreakout

The spectra evolverapidly as the frontcools

Long-Term Light Curve Evolution

Late Time Spectra

spectral features after breakout may enable usto distinguish betweenPISN and CC SNe

Conclusions

• PISN will be visible to JWST out to z ~ 10 ; strong lensing may enable their detection out to z ~ 15 (Holz, Whalen & Fryer 2010 ApJ in prep)

• dedicated ground-based followup with 30-meter class telescopes for primordial SNe spectroscopy

• discrimination between Pop III PISN and Pop III CC SNe will be challenging but offers the first direct constraints on the Pop III IMF

• complementary detection of Pop III PISN remnants by the SZ effect may be possible (Whalen, Bhattacharya & Holz 2010, ApJ in prep)