The bivariate gas-stellar mass distributions and the mass functions of early- and late-type galaxies at z∼0z\sim0

We report the bivariate HI- and H$_2$-stellar mass distributions of local galaxies in addition of an inventory of galaxy mass functions, MFs, for HI, H$_2$, cold gas, and baryonic mass, separately into early- and late-type galaxies. The MFs are determined using the HI and H$_2$ conditional distributions and the galaxy stellar mass function, GSMF. For the conditional distributions we use the compilation presented in Calette et al. 2018. For determining the GSMF from $M_{\ast}\sim3\times10^{7}$ to $3\times10^{12}$ $M_{\odot}$, we combine two spectroscopic samples from the SDSS at the redshift range $0.0033<z<0.2$. We find that the low-mass end slope of the GSMF, after correcting from surface brightness incompleteness, is $\alpha\approx-1.4$, consistent with previous determinations. The obtained HI MFs agree with radio blind surveys. Similarly, the H$_2$ MFs are consistent with CO follow-up optically-selected samples. We estimate the impact of systematics due to mass-to-light ratios and find that our MFs are robust against systematic errors. We deconvolve our MFs from random errors to obtain the intrinsic MFs. Using the MFs, we calculate cosmic density parameters of all the baryonic components. Baryons locked inside galaxies represent 5.4% of the universal baryon content, while $\sim96$% of the HI and H$_2$ mass inside galaxies reside in late-type morphologies. Our results imply cosmic depletion times of H$_2$ and total neutral H in late-type galaxies of $\sim 1.3$ and 7.2 Gyr, respectively, which shows that late type galaxies are on average inefficient in converting H$_2$ into stars and in transforming HI gas into H$_2$. Our results provide a fully self-consistent empirical description of galaxy demographics in terms of the bivariate gas--stellar mass distribution and their projections, the MFs. This description is ideal to compare and/or to constrain galaxy formation models.Comment: 37 pages, 17 figures. Accepted for publication in PASA. A code that displays tables and figures with all the relevant statistical distributions and correlations discussed in this paper is available here https://github.com/arcalette/Python-code-to-generate-Rodriguez-Puebla-2020-result

The Massive Satellite Population Of Milky-Way-Sized Galaxies

Several occupational distributions for satellite galaxies more massive than m(*) approximate to 4 x 10(7) M-circle dot around Milky-Way (MW)-sized hosts are presented and used to predict the internal dynamics of these satellites as a function of m(*). For the analysis, a large galaxy group mock catalog is constructed on the basis of (sub) halo-to-stellar mass relations fully constrained with currently available observations, namely the galaxy stellar mass function decomposed into centrals and satellites, and the two-point correlation functions at different masses. We find that 6.6% of MW-sized galaxies host two satellites in the mass range of the Small and Large Magellanic Clouds (SMC and LMC, respectively). The probabilities of the MW-sized galaxies having one satellite equal to or larger than the LMC, two satellites equal to or larger than the SMC, or three satellites equal to or larger than Sagittarius (Sgr) are approximate to 0.26, 0.14, and 0.14, respectively. The cumulative satellite mass function of the MW, N-s(>= m(*)), down to the mass of the Fornax dwarf is within the 1 sigma distribution of all the MW-sized galaxies. We find that MW-sized hosts with three satellites more massive than Sgr (as the MW) are among the most common cases. However, the most and second most massive satellites in these systems are smaller than the LMC and SMC by roughly 0.7 and 0.8 dex, respectively. We conclude that the distribution N-s(>= m(*)) for MW-sized galaxies is quite broad, the particular case of the MW being of low frequency but not an outlier. The halo mass of MW-sized galaxies correlates only weakly with N-s(>= m(*)). Then, it is not possible to accurately determine the MW halo mass by means of its N-s(>= m(*)); from our catalog, we constrain a lower limit of 1.38 x 10(12) M-circle dot at the 1 sigma level. Our analysis strongly suggests that the abundance of massive subhalos should agree with the abundance of massive satellites in all MW-sized hosts, i.e., there is not a missing (massive) satellite problem for the Lambda CDM cosmology. However, we confirm that the maximum circular velocity, v(max), of the subhalos of satellites smaller than m(*) similar to 10(8) M-circle dot is systematically larger than the v(max) inferred from current observational studies of the MW bright dwarf satellites; different from previous works, this conclusion is based on an analysis of the overall population of MW-sized galaxies. Some pieces of evidence suggest that the issue could refer only to satellite dwarfs but not to central dwarfs, then environmental processes associated with dwarfs inside host halos combined with supernova-driven core expansion should be on the basis of the lowering of v(max).CONACyT 167332, 128556McDonald Observator

Dark Matter Halo Properties vs. Local Density and Cosmic Web Location

We study the effects of the local environmental density and the cosmic web environment (filaments, walls, and voids) on key properties of dark matter halos using the Bolshoi-Planck LCDM cosmological simulation. The z = 0 simulation is analysed into filaments, walls, and voids using the SpineWeb method and also the VIDE package of tools, both of which use the watershed transform. The key halo properties that we study are the specific mass accretion rate, spin parameter, concentration, prolateness, scale factor of the last major merger, and scale factor when the halo had half of its z = 0 mass. For all these properties, we find that there is no discernible difference between the halo properties in filaments, walls, or voids when compared at the same environmental density. As a result, we conclude that environmental density is the core attribute that affects these properties. This conclusion is in line with recent findings that properties of galaxies in redshift surveys are independent of their cosmic web environment at the same environmental density at z ~ 0. We also find that the local web environment of the Milky Way and the Andromeda galaxies near the centre of a cosmic wall does not appear to have any effect on the properties of these galaxies' dark matter halos except for their orientation, although we find that it is rather rare to have such massive halos near the centre of a relatively small cosmic wall.Comment: 23 page

Decaimiento Raro del Muon Con un Modelo de Simetría Horizontal

En particulas elementales las masas de las particulas; fermiones y bosones, son generados al implementar un mecanismo llamado “Rompimiento Espontaneo de Simetria” (SSB). Las masas de los fermiones conocidos, quarks y leptones, son generados al romperse espontaneamente el grupo de simetria electrodebil U(1)Q de la “Electrodinamica Cuantica” (QED). En fisica de particulas elementales existe el llamado Modelo Estandar (SM) que ha tenido un enorme exito para describir cualitativamente y cuantitativamente la gran mayoria de los resultados experimentales encontrados ahora. Desde un punto de vista tecnico el SM implementa el SSB en el grupo de simetria electrodebil con la introduccion de un doblete de Escalares Fundamentales. Este mecanismo implica la existencia de una particula escalar neutra fisica que se le llama “Boson de Higgs”, el cual se le sigue buscando pero hasta ahora no se le ha encontrado