Zobrazeno 1 - 10
of 248
pro vyhledávání: '"WHALEN, DANIEL J."'
High redshift observations of 10$^9$ M$_\odot$ supermassive black holes (SMBHs) at $z \sim7$ and `Little Red Dots' that may host overmassive black holes at $z>4$ suggests the existence of so-called heavy seeds (>1000 M$_\odot$) in the early Universe.
Externí odkaz:
http://arxiv.org/abs/2410.06141
Autor:
Nandal, Devesh, Zwick, Lorenz, Whalen, Daniel J., Mayer, Lucio, Ekström, Sylvia, Meynet, Georges
Publikováno v:
A&A 689, A351 (2024)
The first stars formed over five orders of magnitude in mass by accretion in primordial dark matter halos. We study the evolution of massive, very massive and supermassive primordial (Pop III) stars over nine orders of magnitude in accretion rate. We
Externí odkaz:
http://arxiv.org/abs/2407.06994
Recent calculations indicate that radio emission from quasars at $z \sim$ 6 - 7 could be detected at much earlier stages of evolution, at $z \sim$ 14 - 15, by the Next-Generation Very Large Array (ngVLA) and the Square Kilometer Array (SKA). However,
Externí odkaz:
http://arxiv.org/abs/2401.07910
The recent discovery of a 4 $\times$ 10$^7$ M$_{\odot}$ black hole (BH) in UHZ1 at $z =$ 10.3, just 450 Myr after the big bang, suggests that the seeds of the first quasars may have been direct-collapse black holes (DCBHs) from the collapse of superm
Externí odkaz:
http://arxiv.org/abs/2308.03837
Nearly 300 quasars have now been found at $z >$ 6, including nine at $z >$ 7. They are thought to form from the collapse of supermassive primordial stars to 10$^4$ - 10$^5$ M$_{\odot}$ black holes at $z \sim$ 20 - 25, which then rapidly grow in the l
Externí odkaz:
http://arxiv.org/abs/2304.12333
Autor:
Chen, Ke-Jung, Tang, Ching-Yao, Whalen, Daniel J., Ho, Meng-Yuan, Tsai, Sung-Han, Ou, Po-Sheng, Ono, Masaomi
Massive Pop III stars can die as energetic supernovae that enrich the early universe with metals and determine the properties of the first galaxies. With masses of about $10^9$ Msun at $z \gtrsim 10$, these galaxies are believed to be the ancestors o
Externí odkaz:
http://arxiv.org/abs/2211.06016
Supermassive stars forming at $z \sim$ 15 - 20 are one of the leading contenders for the origin of the first quasars, over 200 of which have now been discovered at $z >$ 6. These stars likely form in pristine, atomically cooled haloes immersed in str
Externí odkaz:
http://arxiv.org/abs/2208.00008
Autor:
Latif, Muhammad A., Whalen, Daniel J., Khochfar, Sadegh, Herrington, Nicholas P., Woods, Tyrone E.
How quasars powered by supermassive black holes (SMBHs) formed less than a billion years after the Big Bang is still one of the outstanding problems in astrophysics 20 years after their discovery$^{1-4}$. Cosmological simulations suggest that rare co
Externí odkaz:
http://arxiv.org/abs/2207.05093
Direct-collapse black holes (DCBHs) may be the seeds of the first quasars, over 200 of which have now been detected at $z > 6$ . The James Webb Space Telescope (JWST) could detect DCBHs in the near infrared (NIR) at $z \lesssim 20$ and probe the evol
Externí odkaz:
http://arxiv.org/abs/2205.14163
Supermassive primordial stars with masses exceeding $\sim10^5\,M_{\odot}$ that form in atomically cooled halos are the leading candidates for the origin of high-redshift quasars with $z>6$. Recent numerical simulations, however, find that multiple ac
Externí odkaz:
http://arxiv.org/abs/2112.09142