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We revisit the relation between magnetic-field strength ($B$) and gas density ($rho$) for contracting interstellar clouds and fragments (or, cores), which is central in observationally determining the dynamical importance of magnetic fields in cloud evolution and star formation. Recently, it has been claimed that a relation $B propto rho^{2/3} $ is statistically preferred over $B propto rho^{1/2}$ in molecular clouds, when magnetic field detections and nondetections from Zeeman observations are combined. This finding has unique observational implications on cloud and core geometry: The relation $B propto rho^{2/3} $ can only be realized under spherical contraction. However, no indication of spherical geometry can be found for the objects used in the original statistical analysis of the $B-rho$ relation. We trace the origin of the inconsistency to simplifying assumptions in the statistical model used to arrive at the $Bpropto rho^{2/3}$ conclusion and to an underestimate of observational uncertainties in the determination of cloud and core densities. We show that, when these restrictive assumptions are relaxed, $B propto rho^{1/2}$ is the preferred relation for the (self-gravitating) molecular-cloud data, as theoretically predicted four decades ago.
We revisit the relation between the stellar surface density, the gas surface density, and the gas-phase metallicity of typical disk galaxies in the local Universe with the SDSS-IV/MaNGA survey, using the star formation rate surface density as an indi
We briefly discuss constraints on supersymmetric hybrid inflation models and examine the consistency of brane inflation models. We then address the implications for inflationary scenarios resulting from the strong constraints on the cosmic (super)str
We statistically evaluate the relative orientation between gas column density structures, inferred from Herschel submillimetre observations, and the magnetic field projected on the plane of sky, inferred from polarized thermal emission of Galactic du
It is well-established that a gas density gradient inside molecular clouds and clumps raises their star formation rate compared to what they would experience from a gas reservoir of uniform density. This effect should be observed in the relation betw
We present an updated version of the mass--metallicity relation (MZR) using integral field spectroscopy data obtained from 734 galaxies observed by the CALIFA survey. These unparalleled spatially resolved spectroscopic data allow us to determine the