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Tricarbon and pentacarbon monoxides have been detected towards the Taurus Molecular Cloud (TMC-1) with relatively important abundances. Understanding the chemical formation of these molecules requires interpreting their observational spectra by mean of non-local thermodynamical equilibrium modelling. For this purpose, we report rate coefficients of  C3O and  C5O induced by collision with He for temperatures up to 100 K. These data are obtained by calculating inelastic cross sections for the 31 low-lying rotational levels of  C3O and  C5O using the close-coupling approach. The comparison of the new rate coefficients with those of HC3N and HC5N, previously used to interpret the observational spectra of  C3O and  C5O, reveals differences of up to an order of magnitude. The effect of the new collisional rate coefficients in radiative transfer calculations is checked by computing the excitation temperatures for some transitions and simulating the  C3O and  C5O column densities observed towards TMC-1. Our findings suggest that the use of HC n N as template for C n O may lead to local thermodynamic equilibrium conditions for gas densities as low as ∼103  cm−3. Regarding the interpretation of the observational spectra, using radiative transfer modelling based on the actual C n O collisional rate coefficients instead of rotational diagram analysis leads to underestimate the column densities reported in the literature by up to 25 per cent and accordingly the  C3O/ C5O abundance ratio by up to 50 per cent. We expect that the new rate coefficients and the radiative transfer calculations presented in this work will encourage further modellings of the C n O abundance and accordingly constrain the chemistry. [ABSTRACT FROM AUTHOR]

LISA Pathfinder (LPF) was a technology pioneering mission designed to test key technologies required for gravitational wave detection in space. In the low frequency regime (milliHertz and below), where space-based gravitational wave observatories will operate, temperature fluctuations play a crucial role since they can couple into the interferometric measurement and the test masses' free-fall accuracy in many ways. A dedicated temperature measurement subsystem, with noise levels in 10  |$\mu$| K Hz−1/2 down to 1 mHz was part of the diagnostics unit onboard LPF. In this paper we report on the temperature measurements throughout mission operations, characterize the thermal environment, estimate transfer functions between different locations, and report temperature stability (and its time evolution) at frequencies as low as 10  |$\mu$| Hz, where typically values around 1 K Hz−1/2 were measured. [ABSTRACT FROM AUTHOR]