TY - JOUR
T1 - On the Observability of Individual Population III Stars and Their Stellar-mass Black Hole Accretion Disks through Cluster Caustic Transits
AU - Windhorst, Rogier
AU - Timmes, Francis
AU - Wyithe, J. Stuart B.
AU - Alpaslan, Mehmet
AU - Andrews, Stephen K.
AU - Coe, Daniel
AU - Diego, Jose M.
AU - Dijkstra, Mark
AU - Driver, Simon P.
AU - Kelly, Patrick L.
AU - Kim, Duho
N1 - Publisher Copyright:
© 2018. The American Astronomical Society. All rights reserved.
PY - 2018/2
Y1 - 2018/2
N2 - We summarize panchromatic Extragalactic Background Light data to place upper limits on the integrated near-infrared surface brightness (SB) that may come from Population III stars and possible accretion disks around their stellar-mass black holes (BHs) in the epoch of First Light, broadly taken from z ≃ 7-17. Theoretical predictions and recent near-infrared power spectra provide tighter constraints on their sky signal. We outline the physical properties of zero-metallicity Population III stars from MESA stellar evolution models through helium depletion and of BH accretion disks at z ≳ 7. We assume that second-generation non-zero-metallicity stars can form at higher multiplicity, so that BH accretion disks may be fed by Roche-lobe overflow from lower-mass companions. We use these near-infrared SB constraints to calculate the number of caustic transits behind lensing clusters that the James Webb Space Telescope and the next-generation ground-based telescopes may observe for both Population III stars and their BH accretion disks. Typical caustic magnifications can be μ ≃ 104-105, with rise times of hours and decline times of ≲1 year for cluster transverse velocities of vT ≲ 1000 km s-1. Microlensing by intracluster-medium objects can modify transit magnifications but lengthen visibility times. Depending on BH masses, accretion-disk radii, and feeding efficiencies, stellar-mass BH accretion-disk caustic transits could outnumber those from Population III stars. To observe Population III caustic transits directly may require monitoring 3-30 lensing clusters to AB ≲ 29 mag over a decade.
AB - We summarize panchromatic Extragalactic Background Light data to place upper limits on the integrated near-infrared surface brightness (SB) that may come from Population III stars and possible accretion disks around their stellar-mass black holes (BHs) in the epoch of First Light, broadly taken from z ≃ 7-17. Theoretical predictions and recent near-infrared power spectra provide tighter constraints on their sky signal. We outline the physical properties of zero-metallicity Population III stars from MESA stellar evolution models through helium depletion and of BH accretion disks at z ≳ 7. We assume that second-generation non-zero-metallicity stars can form at higher multiplicity, so that BH accretion disks may be fed by Roche-lobe overflow from lower-mass companions. We use these near-infrared SB constraints to calculate the number of caustic transits behind lensing clusters that the James Webb Space Telescope and the next-generation ground-based telescopes may observe for both Population III stars and their BH accretion disks. Typical caustic magnifications can be μ ≃ 104-105, with rise times of hours and decline times of ≲1 year for cluster transverse velocities of vT ≲ 1000 km s-1. Microlensing by intracluster-medium objects can modify transit magnifications but lengthen visibility times. Depending on BH masses, accretion-disk radii, and feeding efficiencies, stellar-mass BH accretion-disk caustic transits could outnumber those from Population III stars. To observe Population III caustic transits directly may require monitoring 3-30 lensing clusters to AB ≲ 29 mag over a decade.
KW - accretion, accretion disks
KW - galaxies: clusters: general
KW - gravitational lensing: strong
KW - infrared: diffuse background
KW - stars: Population III
KW - stars: black holes
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U2 - 10.3847/1538-4365/aaa760
DO - 10.3847/1538-4365/aaa760
M3 - Article
AN - SCOPUS:85042535261
SN - 0067-0049
VL - 234
JO - Astrophysical Journal, Supplement Series
JF - Astrophysical Journal, Supplement Series
IS - 2
M1 - 41
ER -