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FUEL. “However, engine-driven transients such as long gamma-ray bursts, broad-lined SNe Ic, and superluminous SNe Ic do not show evidence for any hydrogen in their progenitor stars. These transients are likely driven by a rapidly rotating central engine from a (mostly) carbon–oxygen progenitor star.” (SNe Ic = soecific superluminous black hole transient). https://lnkd.in/dApxk5K View in LinkedIn

MURKY ORIGINS. “However, because collapsing blue supergiants likely formed as a result of a prior binary interaction, few binary scenarios predict them to be the progenitors of BH mergers or XRBs, though they could plausibly be progenitors of ultra-long gamma-ray bursts.” (BH = black hole; XRBs = X-ray binaries). https://lnkd.in/dApxk5K View in LinkedIn

SPINNING INFINITY. “Rotating blue supergiants, such as the progenitor of SN 1987A, may also give rise to rapidly rotating BHs. For these stars, neutrino-mediated mass loss will fail to unbind most of the hydrogen envelope, and a rapidly rotating BH will be produced if the AM in the hydrogen envelope is accreted by the BH.” (BH = black hole; AM = angular momentum). https://lnkd.in/dApxk5K View in LinkedIn

BLACK HOLE SPIN. “Spin is one of only three fundamental properties of black holes (BHs), but there are few reliable predictions of natal BH spins. The BH spin is determined by the angular momentum (AM) content of the core of the star that collapses into the BH. Yet our ability to predict internal stellar rotation rates and AM content has been limited by sparse observational constraints and the complex magnetohydrodynamics of differentially rotating stars.” (BH = black hole; AM = angular momentum). https://lnkd.in/dApxk5K View in LinkedIn

EVOLUTION OF BLACK HOLES. “Because so few philosophers have worked on these issues, many questions and problems of great possible interest have not been investigated philosophically at all; others have had only the barest starts made on them; consequently, several sections discussed in this article merely raise questions and point to problems that deserve philosophical attention. The field is wide open for expansive and intensive exploration.” https://lnkd.in/dPXn5gh View in LinkedIn

A Girona artesenal bookbinder who still occaisionally works in velum. Another dying breed. Extraordinary workshop of old tools. View in LinkedIn

HEISENBERG, BOHR, AND EINSTEIN. “This exploration brought them in contact with a strange and unexpected reality that shattered the foundations of their world view and forced them to think in entirely new ways. The material world they observed no longer appeared as a machine, made up of a multitude of separate objects, but rather as an indivisible whole; a network of relationships that included the human observer in an essential way.” (Welcome to Wonderland!). https://lnkd.in/d9WF55y View in LinkedIn

ORIGINS OF HUGENESS. “Several theories have been postulated for the origin of SMBH seeds. Some of the leading candidates are: (a) Population III star remnants (100–1000 M⊙, form at 15 < z < 30), (b) Direct collapse black holes (104–106 M⊙, form at 10 < z < 20), and (c) Collapsing stellar clusters (∼103 M⊙, form at high or low z).” (M⊙ = unit of celestial mass; SMBH = supermassive black hole). https://lnkd.in/dYX7TQV View in LinkedIn

WHAT PERSPECTIVE!! “The idea of IMBHs as SMBH seeds is appealing because of the sheer difficulty in creating a 109 M⊙ SMBH in less than one billion years.” (IMBHs = intermediate mass black holes; SMBH = supermassive black holes). https://lnkd.in/dYX7TQV View in LinkedIn

FILLING THE GAP. “The Laser Interferometer Space Antenna (LISA) will demystify IMBHs by detecting the mergers of these objects out to extremely high redshifts, while measuring their masses with extremely high precision. These observations of merging IMBHs will allow us to constrain the formation mechanism and subsequent evolution of massive black holes, from the ‘dark ages’ to the present day.” (IMBHs = intermediate mass black holes). https://lnkd.in/dYX7TQV View in LinkedIn