O. Valenzuela | Universidad Nacional Autónoma de México (original) (raw)
Papers by O. Valenzuela
arXiv: Astrophysics of Galaxies, 2017
We present here the characterization of the main properties of a sample of 98 AGN host galaxies, ... more We present here the characterization of the main properties of a sample of 98 AGN host galaxies, both type-II and type-I, in comparison with those of about 2700 non-active galaxies observed by the MaNGA survey. We found that AGN hosts are morphologically early-type or early-spirals. For a given morphology AGN hosts are, in average, more massive, more compact, more central peaked and rather pressurethan rotational-supported systems. We confirm previous results indicating that AGN hosts are located in the intermediate/transition region between star-forming and non-star-forming galaxies (i.e., the so-called green valley), both in the ColorMagnitude and the star formation main sequence diagrams. Taking into account their relative distribution in terms of the stellar metallicity and oxygen gas abundance and a rough estimation of their molecular gas content, we consider that these galaxies are in the process of halting/quenching the star formation, in an actual transition between both gro...
The Astrophysical Journal, 2016
Proceedings of The International Astronomical Union, 2009
The Astrophysical Journal, 2002
The Astrophysical Journal, 2010
Monthly Notices of the Royal Astronomical Society, 2011
The Astronomical Journal, 2013
We study the radial acceleration relation (RAR) for early-type galaxies (ETGs) in the SDSS MaNGA ... more We study the radial acceleration relation (RAR) for early-type galaxies (ETGs) in the SDSS MaNGA MPL5 data set. The complete ETG sample show a slightly offset RAR from the relation reported by McGaugh et al. (2016) at the low-acceleration end; we find that the deviation is due to the fact that the slow rotators show a systematically higher acceleration relation than the McGaugh's RAR, while the fast rotators show a consistent acceleration relation to McGaugh's RAR. There is a 1σ significant difference between the acceleration relations of the fast and slow rotators, suggesting that the acceleration relation correlates with the galactic spins, and that the slow rotators may have a different mass distribution compared with fast rotators and late-type galaxies. We suspect that the acceleration relation deviation of slow rotators may be attributed to more galaxy merger events, which would disrupt the original spins and correlated distributions of baryons and dark matter orbits i...
Monthly Notices of the Royal Astronomical Society, 2021
We study the vertical perturbations in the galactic disc of the Milky Way-size high-resolution hy... more We study the vertical perturbations in the galactic disc of the Milky Way-size high-resolution hydrodynamical cosmological simulation named GARROTXA. We detect phase spirals in the vertical projection Z − VZ of disc’s stellar particles for the first time in this type of simulations. Qualitatively similar structures were detected in the recent Gaia data, and their origin is still under study. In our model the spiral-like structures in the phase space are present in a wide range of times and locations across the disc. By accounting for an evolving mix of stellar populations, we observe that, as seen in the data, the phase spirals are better observed in the range of younger-intermediate star particles. We measure the intensity of the spiral with a Fourier decomposition and find that these structures appear stronger near satellite pericenters. Current dynamical models of the phase spiral considering a single perturber required a mass at least of the order of 1010 M⊙, but all three of ou...
It was argued in the past that bulges of galaxies cannot be formed through collisionless secular ... more It was argued in the past that bulges of galaxies cannot be formed through collisionless secular evolution because that would violate constraints on the phase-space density: the phase-space density in bulges is several times larger than in the inner parts of discs. We show that these arguments against secular evolution are not correct. Observations give estimates of the coarse-grained phase-space densities of galaxies, f ′ = ρs/σRσφσz, where ρs is stellar density and σR, σφ, σz are the radial, tangential, and vertical rms velocities of stars. Using high-resolution N-body simulations, we study the evolution of f ′ in discs of Galaxy-size models. During the secular evolution, the discs, which are embedded in live Cold Dark Matter haloes, form a bar and then a thick, dynamically hot, central mass concentration. In the course of evolution f ′ declines at all radii, not just in the central region. The decline is different in different parts of the disc. In the inner disc, f ′ (R) develop...
We study the phase space available to the local stellar distribution using a Galactic potential c... more We study the phase space available to the local stellar distribution using a Galactic potential consistent with several recent observational constraints. We find that the induced phase space structure has several observable consequences. The spiral arm contribution to the kinematic structure in the solar neighborhood may be as important as the one produced by the Galactic bar. We suggest that some of the stellar kinematic groups in the solar neighborhood, like the Hercules structure and the kinematic branches, can be created by the dynamical resonances of self-gravitating spiral arms and not exclusively by the Galactic bar. A structure coincident with the Arcturus kinematic group is developed when a hot stellar disk population is considered, which introduces a new perspective on the interpretation of its extragalactic origin. A bar-related resonant mechanism can modify this kinematic structure. We show that particles in the dark matter disk-like structure predicted by recent LCDM ga...
Revista Mexicana De Astronomia Y Astrofisica, 2008
Resumen en: We have initiated a project that aims to revise the robustness of the suggestions of ... more Resumen en: We have initiated a project that aims to revise the robustness of the suggestions of the dearth of dark matter in the central regions of barred galaxies ...
We explore the possible constraints to the dark matter (DM) mass power spectrum amplitude at sub-... more We explore the possible constraints to the dark matter (DM) mass power spectrum amplitude at sub-galactic scales, with the aim to test the properties of DM particle candidates. We present preliminary results discussing the sensitivity of Solar System dynamics and dSph’s wide binaries abundance to the small scale DM distribution. We also discuss possible future avenues.
Journal of Cosmology and Astroparticle Physics, 2021
The Astrophysical Journal Supplement Series, 2017
Monthly Notices of the Royal Astronomical Society, 2016
One of the most intriguing features in the solar neighborhood stellar velocity distribution are t... more One of the most intriguing features in the solar neighborhood stellar velocity distribution are the so called moving groups. These groups are stellar streams observed as overdensities in the velocity space, crossing the region nearby the Sun. At 140 years of their discovery, the understanding of the origin of these kinematic structures is still far from complete. Several scenarios for
Astronomy & Astrophysics, 2015
The Astrophysical Journal, 2004
The Astronomical Journal, 2011
arXiv: Astrophysics of Galaxies, 2017
We present here the characterization of the main properties of a sample of 98 AGN host galaxies, ... more We present here the characterization of the main properties of a sample of 98 AGN host galaxies, both type-II and type-I, in comparison with those of about 2700 non-active galaxies observed by the MaNGA survey. We found that AGN hosts are morphologically early-type or early-spirals. For a given morphology AGN hosts are, in average, more massive, more compact, more central peaked and rather pressurethan rotational-supported systems. We confirm previous results indicating that AGN hosts are located in the intermediate/transition region between star-forming and non-star-forming galaxies (i.e., the so-called green valley), both in the ColorMagnitude and the star formation main sequence diagrams. Taking into account their relative distribution in terms of the stellar metallicity and oxygen gas abundance and a rough estimation of their molecular gas content, we consider that these galaxies are in the process of halting/quenching the star formation, in an actual transition between both gro...
The Astrophysical Journal, 2016
Proceedings of The International Astronomical Union, 2009
The Astrophysical Journal, 2002
The Astrophysical Journal, 2010
Monthly Notices of the Royal Astronomical Society, 2011
The Astronomical Journal, 2013
We study the radial acceleration relation (RAR) for early-type galaxies (ETGs) in the SDSS MaNGA ... more We study the radial acceleration relation (RAR) for early-type galaxies (ETGs) in the SDSS MaNGA MPL5 data set. The complete ETG sample show a slightly offset RAR from the relation reported by McGaugh et al. (2016) at the low-acceleration end; we find that the deviation is due to the fact that the slow rotators show a systematically higher acceleration relation than the McGaugh's RAR, while the fast rotators show a consistent acceleration relation to McGaugh's RAR. There is a 1σ significant difference between the acceleration relations of the fast and slow rotators, suggesting that the acceleration relation correlates with the galactic spins, and that the slow rotators may have a different mass distribution compared with fast rotators and late-type galaxies. We suspect that the acceleration relation deviation of slow rotators may be attributed to more galaxy merger events, which would disrupt the original spins and correlated distributions of baryons and dark matter orbits i...
Monthly Notices of the Royal Astronomical Society, 2021
We study the vertical perturbations in the galactic disc of the Milky Way-size high-resolution hy... more We study the vertical perturbations in the galactic disc of the Milky Way-size high-resolution hydrodynamical cosmological simulation named GARROTXA. We detect phase spirals in the vertical projection Z − VZ of disc’s stellar particles for the first time in this type of simulations. Qualitatively similar structures were detected in the recent Gaia data, and their origin is still under study. In our model the spiral-like structures in the phase space are present in a wide range of times and locations across the disc. By accounting for an evolving mix of stellar populations, we observe that, as seen in the data, the phase spirals are better observed in the range of younger-intermediate star particles. We measure the intensity of the spiral with a Fourier decomposition and find that these structures appear stronger near satellite pericenters. Current dynamical models of the phase spiral considering a single perturber required a mass at least of the order of 1010 M⊙, but all three of ou...
It was argued in the past that bulges of galaxies cannot be formed through collisionless secular ... more It was argued in the past that bulges of galaxies cannot be formed through collisionless secular evolution because that would violate constraints on the phase-space density: the phase-space density in bulges is several times larger than in the inner parts of discs. We show that these arguments against secular evolution are not correct. Observations give estimates of the coarse-grained phase-space densities of galaxies, f ′ = ρs/σRσφσz, where ρs is stellar density and σR, σφ, σz are the radial, tangential, and vertical rms velocities of stars. Using high-resolution N-body simulations, we study the evolution of f ′ in discs of Galaxy-size models. During the secular evolution, the discs, which are embedded in live Cold Dark Matter haloes, form a bar and then a thick, dynamically hot, central mass concentration. In the course of evolution f ′ declines at all radii, not just in the central region. The decline is different in different parts of the disc. In the inner disc, f ′ (R) develop...
We study the phase space available to the local stellar distribution using a Galactic potential c... more We study the phase space available to the local stellar distribution using a Galactic potential consistent with several recent observational constraints. We find that the induced phase space structure has several observable consequences. The spiral arm contribution to the kinematic structure in the solar neighborhood may be as important as the one produced by the Galactic bar. We suggest that some of the stellar kinematic groups in the solar neighborhood, like the Hercules structure and the kinematic branches, can be created by the dynamical resonances of self-gravitating spiral arms and not exclusively by the Galactic bar. A structure coincident with the Arcturus kinematic group is developed when a hot stellar disk population is considered, which introduces a new perspective on the interpretation of its extragalactic origin. A bar-related resonant mechanism can modify this kinematic structure. We show that particles in the dark matter disk-like structure predicted by recent LCDM ga...
Revista Mexicana De Astronomia Y Astrofisica, 2008
Resumen en: We have initiated a project that aims to revise the robustness of the suggestions of ... more Resumen en: We have initiated a project that aims to revise the robustness of the suggestions of the dearth of dark matter in the central regions of barred galaxies ...
We explore the possible constraints to the dark matter (DM) mass power spectrum amplitude at sub-... more We explore the possible constraints to the dark matter (DM) mass power spectrum amplitude at sub-galactic scales, with the aim to test the properties of DM particle candidates. We present preliminary results discussing the sensitivity of Solar System dynamics and dSph’s wide binaries abundance to the small scale DM distribution. We also discuss possible future avenues.
Journal of Cosmology and Astroparticle Physics, 2021
The Astrophysical Journal Supplement Series, 2017
Monthly Notices of the Royal Astronomical Society, 2016
One of the most intriguing features in the solar neighborhood stellar velocity distribution are t... more One of the most intriguing features in the solar neighborhood stellar velocity distribution are the so called moving groups. These groups are stellar streams observed as overdensities in the velocity space, crossing the region nearby the Sun. At 140 years of their discovery, the understanding of the origin of these kinematic structures is still far from complete. Several scenarios for
Astronomy & Astrophysics, 2015
The Astrophysical Journal, 2004
The Astronomical Journal, 2011