15,137 research outputs found
The radial acceleration relation is a natural consequence of the baryonic Tully-Fisher relation
Galaxies covering several orders of magnitude in stellar mass and a variety
of Hubble types have been shown to follow the "Radial Acceleration Relation"
(RAR), a relationship between , the observed circular acceleration
of the galaxy, and , the acceleration due to the total baryonic
mass of the galaxy. For accelerations above ,
traces , asymptoting to the 1:1 line. Below this
scale, there is a break in the relation such that . We show that the RAR slope, scatter and the acceleration scale are
all natural consequences of the well-known baryonic Tully-Fisher relation
(BTFR). We further demonstrate that galaxies with a variety of baryonic and
dark matter (DM) profiles and a wide range of dark halo and galaxy properties
(well beyond those expected in CDM) lie on the RAR if we simply require that
their rotation curves satisfy the BTFR. We explore conditions needed to break
this degeneracy: sub-kpc resolved rotation curves inside of "cored"
DM-dominated profiles and/or outside kpc could lie on BTFR but
deviate in the RAR, providing new constraints on DM.Comment: 5 pages, submitted to MNRA
The Effect of Insurance Premium Taxes on Employment
This report provides estimates of the effect of the insurance premium taxes on state-level employment in the insurance industry. FRC Report 18
Tripropellant engine study
The potential for converting the space shuttle main engine (SSME) to a dual-fuel, dual-mode engine using LOX/hydrocarbon propellants in mode 1 and LOX/H2 in mode 2 was examined. Various engine system concepts were formulated that included staged combustion and gas generator turbine power cycles, and LOX/RP-1, LOX/CH4, and LOX/C3H8 mode 1 propellants. Both oxidizer and fuel regenerative cooling were considered. All of the SSME major components were examined to determine their adaptability to the candidate dual-fuel engines
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