2022, Colombo, D., Duarte-Cabral, A., Pettitt, A.R., Urquhart, J. S., Wyrowski, F., Csengeri, T., Neralwar, K.R., Schuller, F., Menten, K.M., Anderson, L., Barnes, P., Beuther, H., Bronfman, L., Eden, D., Ginsburg, A., Henning, T., König, C., Lee, M.-Y., Mattern, M., Medina, S., Ragan, S.E., Rigby, A. J., Sánchez-Monge, Á., Traficante, A., Yang, A. Y., Wienen, M.

The morphology of the Milky Way is still a matter of debate. In order to shed light on uncertainties surrounding the structure of the Galaxy, in this paper, we study the imprint of spiral arms on the distribution and properties of its molecular gas. To do so, we take full advantage of the SEDIGISM (Structure, Excitation, and Dynamics of the Inner Galactic Interstellar Medium) survey that observed a large area of the inner Galaxy in the 13CO (2-1) line at an angular resolution of 28′′. We analyse the influences of the spiral arms by considering the features of the molecular gas emission as a whole across the longitude-velocity map built from the full survey. Additionally, we examine the properties of the molecular clouds in the spiral arms compared to the properties of their counterparts in the inter-arm regions. Through flux and luminosity probability distribution functions, we find that the molecular gas emission associated with the spiral arms does not differ significantly from the emission between the arms. On average, spiral arms show masses per unit length of ~105-106 M⊙ kpc-1. This is similar to values inferred from data sets in which emission distributions were segmented into molecular clouds. By examining the cloud distribution across the Galactic plane, we infer that the molecular mass in the spiral arms is a factor of 1.5 higher than that of the inter-arm medium, similar to what is found for other spiral galaxies in the local Universe. We observe that only the distributions of cloud mass surface densities and aspect ratio in the spiral arms show significant differences compared to those of the inter-arm medium; other observed differences appear instead to be driven by a distance bias. By comparing our results with simulations and observations of nearby galaxies, we conclude that the measured quantities would classify the Milky Way as a flocculent spiral galaxy, rather than as a grand-design one.

2019, Smirnova-Pinchukova, I., Husemann, B., Busch, G., Appleton, P., Bethermin, M., Combes, F., Croom, S., Davis, T.A., Fischer, C., Gaspari, M., Groves, B., Klein, R., O’Dea, C.P., Pérez-Torres, M., Scharwächter, J., Singha, M., Tremblay, G.R., Urrutia, T.

The [C ii]λ158 µm line is one of the strongest far-infrared (FIR) lines and an important coolant in the interstellar medium of galaxies that is accessible out to high redshifts. The excitation of [C ii] is complex and can best be studied in detail at low redshifts. Here we report the discovery of the highest global [C ii] excess with respect to the FIR luminosity in the nearby AGN host galaxy HE 1353−1917. This galaxy is exceptional among a sample of five targets because the AGN ionization cone and radio jet directly intercept the cold galactic disk. As a consequence, a massive multiphase gas outflow on kiloparsec scales is embedded in an extended narrow-line region. Because HE 1353−1917 is distinguished by these special properties from our four bright AGN, we propose that a global [C ii] excess in AGN host galaxies could be a direct signature of a multiphase AGN-driven outflow with a high mass-loading factor.

2021-4-14, Sánchez, S.F., Walcher, C.J., Lopez-Cobá, C., Barrera-Ballesteros, J.K., Mejía-Narváez, A., Espinosa-Ponce, C., Camps-Fariña, A.

Our understanding of the structure, composition and evolution of galaxies has strongly improved in the last decades, mostly due to new results based on large spectroscopic and imaging surveys. In particular, the nature of ionized gas, its ionization mechanisms, its relation with the stellar properties and chemical composition, the existence of scaling relations that describe the cycle between stars and gas, and the corresponding evolution patterns have been widely explored and described. More recently, the introduction of additional techniques, in particular integral field spectroscopy, and their use in large galaxy surveys, have forced us to re-interpret most of those recent results from a spatially resolved perspective. This review is aimed to complement recent efforts to compile and summarize this change of paradigm in the interpretation of galaxy evolution. To this end we replicate published results, and present novel ones, based on the largest compilation of IFS data of galaxies in the nearby universe to date. © 2021: Instituto de Astronomía, Universidad Nacional Autónoma de México.