M. Martos - Academia.edu (original) (raw)

Papers by M. Martos

Proceedings of the International Astronomical Union, 2012

Monthly Notices of the Royal Astronomical Society, 2013

The Astronomical Journal, 2013

We report calculations of the stellar and gaseous response to a Milky Way mass distribution model... more We report calculations of the stellar and gaseous response to a Milky Way mass distribution model including a spiral pattern with a locus as traced by K-band observations, over imposed on the axisymmetric components in the plane of the disk. The stellar study extends calculations from previous work concerning the self-consistency of the pattern. The stellar response to the imposed spiral mass is studied via computations of the central family of periodic and nearby orbits as a function of the pattern rotation speed, Ωp, among other parameters. A fine grid of values of Ωp was explored ranging from 12 to 25 km s −1 kpc −1. Dynamical self-consistency is highly sensitive to Ωp, with the best fit appearing at 20 km s −1 kpc −1. We give an account of recent independent pieces of theoretical and observational work that are dependent on the value of Ωp, all of which are consistent with the value found here; the recent star formation history of the Milky Way, local inferences of cosmic ray fl...

Journal of The Korean Astronomical Society, 2004

The Astronomical Journal, 1998

We have modelled the Galactic spiral arms as a superposition of oblate spheroids, and added its c... more We have modelled the Galactic spiral arms as a superposition of oblate spheroids, and added its contribution to an axisymmetric Galactic model. We have numerically integrated orbits confined to the midplane of symmetry. Our main findings include: the modified potential gives rise to chaotic orbits. However, chaos is found only in direct orbits as defined in the inertial frame of

We have modeled galactic stellar spiral arms as a superposition of inhomogeneous oblate spheroids... more We have modeled galactic stellar spiral arms as a superposition of inhomogeneous oblate spheroids, and added its contribution to an axisymmetric model of the Galactic mass distribution. The physical characteristics and the spatial extent of the spiral arms, were selected by observations giving us a plausible model for the Galactic potential outside the ILR. With the selected pitch angle, self-consistent

A spiral arm is modeled as a superposition of prolate spheroids. An explicit expression is given ... more A spiral arm is modeled as a superposition of prolate spheroids. An explicit expression is given for the resultant gravitational potential of the arm. Functional forms are also proposed for the vertical gravitational acceleration produced by the stars in the galactic disk, and the density laws for the gas components of the thick galactic disk in the vertical direction. Starting from hydrostatic equilibrium, the gas response to the spiral density wave is studied via numerical simulations of the local gas flow. The galactic magnetic field is included in different geometries. Interesting flow patterns high above from the galactic midplane are found. The transition nearly resembles the hydraulic jump, or bore, from the incompressible flow theory.

An anomolous group of young stars located at high distance z above the Galactic midplane have bee... more An anomolous group of young stars located at high distance z above the Galactic midplane have been found in a number of studies. Although different hypothesis have been put forward to explain their existance, no single hypothesis solves the paradox presented by their early lifetimes in such locations, especially for the most extreme cases. In this work, we propose an in-situ scenario, in which the shocks produced at high z by the spiral density wave promote stellar formation.

The Astrophysical …, 2000

Monthly Notices of The Royal Astronomical Society, 2004

We report calculations of the stellar and gaseous response to a Milky Way mass distribution model... more We report calculations of the stellar and gaseous response to a Milky Way mass distribution model including a spiral pattern with a locus as traced by K-band observations, over imposed on the axisymmetric components in the plane of the disk. The stellar study extends calculations from previous work concerning the self-consistency of the pattern. The stellar response to the imposed

Astroparticle Physics, 2015

Astroparticle Physics, 2012

The Astronomical Journal, 2013

ABSTRACT We present a kinematical study of the nearly edge-on galaxy ESO 379-006 that shows the e... more ABSTRACT We present a kinematical study of the nearly edge-on galaxy ESO 379-006 that shows the existence of extraplanar ionized gas. With Fabry-Perot spectroscopy at Hα, we study the kinematics of ESO 379-006 using velocity maps and position-velocity diagrams parallel to the major and to the minor axis of the galaxy. We build the rotation curve of the disk and discuss the role of projection effects due to the fact of viewing this galaxy nearly edge-on. The twisting of the isovelocities in the radial velocity field of the disk of ESO 379-006 as well as the kinematical asymmetries found in some position-velocity diagrams parallel to the minor axis of the galaxy suggest the existence of deviations to circular motions in the disk that can be modeled and explained with the inclusion of a radial inflow probably generated by a bar or by spiral arms. We succeeded in detecting extraplanar diffuse ionized gas in this galaxy. At the same time, from the analysis of position-velocity diagrams, we found some evidence that the extraplanar gas could lag in rotation velocity with respect to the midplane rotation.

Proceedings of the International Astronomical Union, 2012

Monthly Notices of the Royal Astronomical Society, 2013

The Astronomical Journal, 2013

We report calculations of the stellar and gaseous response to a Milky Way mass distribution model... more We report calculations of the stellar and gaseous response to a Milky Way mass distribution model including a spiral pattern with a locus as traced by K-band observations, over imposed on the axisymmetric components in the plane of the disk. The stellar study extends calculations from previous work concerning the self-consistency of the pattern. The stellar response to the imposed spiral mass is studied via computations of the central family of periodic and nearby orbits as a function of the pattern rotation speed, Ωp, among other parameters. A fine grid of values of Ωp was explored ranging from 12 to 25 km s −1 kpc −1. Dynamical self-consistency is highly sensitive to Ωp, with the best fit appearing at 20 km s −1 kpc −1. We give an account of recent independent pieces of theoretical and observational work that are dependent on the value of Ωp, all of which are consistent with the value found here; the recent star formation history of the Milky Way, local inferences of cosmic ray fl...

Journal of The Korean Astronomical Society, 2004

The Astronomical Journal, 1998

We have modelled the Galactic spiral arms as a superposition of oblate spheroids, and added its c... more We have modelled the Galactic spiral arms as a superposition of oblate spheroids, and added its contribution to an axisymmetric Galactic model. We have numerically integrated orbits confined to the midplane of symmetry. Our main findings include: the modified potential gives rise to chaotic orbits. However, chaos is found only in direct orbits as defined in the inertial frame of

We have modeled galactic stellar spiral arms as a superposition of inhomogeneous oblate spheroids... more We have modeled galactic stellar spiral arms as a superposition of inhomogeneous oblate spheroids, and added its contribution to an axisymmetric model of the Galactic mass distribution. The physical characteristics and the spatial extent of the spiral arms, were selected by observations giving us a plausible model for the Galactic potential outside the ILR. With the selected pitch angle, self-consistent

A spiral arm is modeled as a superposition of prolate spheroids. An explicit expression is given ... more A spiral arm is modeled as a superposition of prolate spheroids. An explicit expression is given for the resultant gravitational potential of the arm. Functional forms are also proposed for the vertical gravitational acceleration produced by the stars in the galactic disk, and the density laws for the gas components of the thick galactic disk in the vertical direction. Starting from hydrostatic equilibrium, the gas response to the spiral density wave is studied via numerical simulations of the local gas flow. The galactic magnetic field is included in different geometries. Interesting flow patterns high above from the galactic midplane are found. The transition nearly resembles the hydraulic jump, or bore, from the incompressible flow theory.

An anomolous group of young stars located at high distance z above the Galactic midplane have bee... more An anomolous group of young stars located at high distance z above the Galactic midplane have been found in a number of studies. Although different hypothesis have been put forward to explain their existance, no single hypothesis solves the paradox presented by their early lifetimes in such locations, especially for the most extreme cases. In this work, we propose an in-situ scenario, in which the shocks produced at high z by the spiral density wave promote stellar formation.

The Astrophysical …, 2000

Monthly Notices of The Royal Astronomical Society, 2004

We report calculations of the stellar and gaseous response to a Milky Way mass distribution model... more We report calculations of the stellar and gaseous response to a Milky Way mass distribution model including a spiral pattern with a locus as traced by K-band observations, over imposed on the axisymmetric components in the plane of the disk. The stellar study extends calculations from previous work concerning the self-consistency of the pattern. The stellar response to the imposed

Astroparticle Physics, 2015

Astroparticle Physics, 2012

The Astronomical Journal, 2013

ABSTRACT We present a kinematical study of the nearly edge-on galaxy ESO 379-006 that shows the e... more ABSTRACT We present a kinematical study of the nearly edge-on galaxy ESO 379-006 that shows the existence of extraplanar ionized gas. With Fabry-Perot spectroscopy at Hα, we study the kinematics of ESO 379-006 using velocity maps and position-velocity diagrams parallel to the major and to the minor axis of the galaxy. We build the rotation curve of the disk and discuss the role of projection effects due to the fact of viewing this galaxy nearly edge-on. The twisting of the isovelocities in the radial velocity field of the disk of ESO 379-006 as well as the kinematical asymmetries found in some position-velocity diagrams parallel to the minor axis of the galaxy suggest the existence of deviations to circular motions in the disk that can be modeled and explained with the inclusion of a radial inflow probably generated by a bar or by spiral arms. We succeeded in detecting extraplanar diffuse ionized gas in this galaxy. At the same time, from the analysis of position-velocity diagrams, we found some evidence that the extraplanar gas could lag in rotation velocity with respect to the midplane rotation.