...$64~{\rm pc/arcsec}$

Throughout this work we assume H₀ =75 km s^-1 Mpc^-1. The distance was calculated via the redshift z=0.0033 of NGC 3718 (NASA Extragalactic Database NED). Pierce & Tully (1988) estimated a slightly differing distance of $(15.5\pm1.2)$ Mpc.

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... ratio

The antenna temperatures $T_{\rm A}^*$ are transformed into the main beam temperatures $T^{\rm mb}_{\rm obs}$ with the forward efficiency and the beam efficiency of the respective observation (see Table 2)

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... 20''

The central 20'' are the area enclosed by a radius of 10''.

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... mass

A conversion factor of

$$\frac{N_{\rm H_2}}{I_{\rm CO_{10}}}=2.3\times10^{20}~{\rm molecules}~{\rm cm^{-2}}~({\rm K}~\mbox{km~s$^{-1}$ })^{-1}$$

(Strong et al. 1988) was used.

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... temperature

Assuming a mass opacity $\kappa_{\nu}\propto\nu$.

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... intensities

Which represent the beam-diluted brightness temperatures of the source.

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