Month: September 2022

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

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

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

SLOW SPIN CORES. “Asteroseismic data for low-mass stars have convincingly demonstrated that the cores of low-mass stars rotate at least an order of magnitude slower than predicted by most prior stellar models. Their predictions of compact object rotation rates are unreliable. We predict extremely slow rotation a ~ 10−2 for BHs born from single stars.” (BH = black hole). https://lnkd.in/dApxk5K View in LinkedIn

ENERGY. “A number of anthropologists believe fire actually refashioned our biology.” An interesting essay. https://lnkd.in/d7wb_xr View in LinkedIn

We see reality through the merest slit of the senses which access but a fraction of the information. View in LinkedIn

MISSING CATEGORY. “Where are the Intermediate Mass Black Holes? Observational evidence has been mounting for the existence of intermediate mass black holes (IMBHs, 102–105 M⊙), but observing them at all, much less constraining their masses, is very challenging.” (M⊙ = unit of celestial mass). https://lnkd.in/dYX7TQV View in LinkedIn

MASS GAP. “The previously assumed ‘mass gap’ between stellar black holes (∼1–100 M⊙) and supermassive black holes (SMBHs; ∼106–109 M⊙) may be filled in, though to what extent is still very uncertain.” (IMBHs = intermediate mass black holes (102–105 M⊙): M⊙ = unit of celestial mass). https://lnkd.in/dYX7TQV View in LinkedIn

SEEDS OF MASSIVENESS. “In one theorized formation channel, IMBHs are the seeds for supermassive black holes in the early universe. As a result, IMBHs are predicted to exist in the local universe in dwarf galaxies, as well as wandering in more massive galaxy halos.” (IMBHs = intermediate mass 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