HEASARC Staff Scientist Position - Applications are now being accepted for a Staff Scientist with significant experience and interest in the technical aspects of astrophysics research, to work in the High Energy Astrophysics Science Archive Research Center (HEASARC) at NASA Goddard Space Flight Center (GSFC) in Greenbelt, MD. Refer to the AAS Job register for full details.

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cosmo

set the cosmology

Set the cosmology used (i.e., $H_0$, $q_0$, and $\Lambda_0$).

Syntax: cosmo <$H_0$><$q_0$><$\Lambda_0$>

where <$H_0$> is the Hubble constant in km/s/Mpc, <$q_0$> is the deceleration parameter, and <$\Lambda_0$> is the cosmological constant. If the cosmological constant is non-zero then at present XSPEC requires that the universe is flat. In this case the value of <$q_0$> will be ignored and XSPEC will assume that $\Omega_{matter}\geq 1-\Lambda_0$. The default values are <$H_0$> = 70, <$q_0$> = 0.0, and <$\Lambda_0$> = 0.73

Examples:

XSPEC12>cosmo 100
// Set <$H_0$>= 100 km/s/Mpc
XSPEC12>cosmo ,0
// Set <$q_0$>= 0
XSPEC12>cosmo „0.7
// Set a flat universe with <$\Lambda_0$>= 0.7

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Last modified: Friday, 23-Aug-2024 13:20:40 EDT

HEASARC Staff Scientist Position - Applications are now being accepted for a Staff Scientist with significant experience and interest in the technical aspects of astrophysics research, to work in the High Energy Astrophysics Science Archive Research Center (HEASARC) at NASA Goddard Space Flight Center (GSFC) in Greenbelt, MD. Refer to the AAS Job register for full details.