THE RELATION BETWEEN DYNAMICS AND STAR FORMATION IN BARRED GALAXIES

Martinez-Garcia, Eric E

doi:10.1088/0004-637X/734/2/122

Title: THE RELATION BETWEEN DYNAMICS AND STAR FORMATION IN BARRED GALAXIES

Full Record
Other Related Research

Abstract

We analyze optical and near-infrared data of a sample of 11 barred spiral galaxies, in order to establish a connection between star formation and bar/spiral dynamics. We find that 22 regions located in the bars and 20 regions in the spiral arms beyond the end of the bar present azimuthal color/age gradients that may be attributed to star formation triggering. Assuming a circular motion dynamic model, we compare the observed age gradient candidates with stellar population synthesis models. A link can then be established with the disk dynamics that allows us to obtain parameters like the pattern speed of the bar or spiral as well as the positions of resonance radii. We subsequently compare the derived pattern speeds with those expected from theoretical and observational results in the literature (e.g., bars ending near corotation). We find a tendency to overestimate bar pattern speeds derived from color gradients in the bar at small radii, away from corotation; this trend can be attributed to non-circular motions of the young stars born in the bar region. In spiral regions, we find that {approx}50% of the color gradient candidates are 'inverse', i.e., with the direction of stellar aging contrary to that of rotation. Themore »« less

Authors:

Martinez-Garcia, Eric E ^[1]

Instituto de AstronomIa, Universidad Nacional Autonoma de Mexico, AP 70-264, Distrito, Federal 04510 (Mexico)

Publication Date:: Mon Jun 20 00:00:00 EDT 2011

OSTI Identifier:: 21576592

Resource Type:: Journal Article

Journal Name:: Astrophysical Journal

Additional Journal Information:: Journal Volume: 734; Journal Issue: 2; Other Information: DOI: 10.1088/0004-637X/734/2/122; Journal ID: ISSN 0004-637X

Country of Publication:: United States

Language:: English

Subject:: 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; GALAXIES; PHOTOMETRY; STAR EVOLUTION; STARS; EVOLUTION

Citation Formats


                    Martinez-Garcia, Eric E, and Gonzalez-Lopezlira, Rosa A., E-mail: martinez@astroscu.unam.mx, E-mail: emartinez@cida.ve, E-mail: r.gonzalez@crya.unam.mx. THE RELATION BETWEEN DYNAMICS AND STAR FORMATION IN BARRED GALAXIES.  United States: N. p., 2011. 
        Web.  doi:10.1088/0004-637X/734/2/122.

Copy to clipboard


                    Martinez-Garcia, Eric E, & Gonzalez-Lopezlira, Rosa A., E-mail: martinez@astroscu.unam.mx, E-mail: emartinez@cida.ve, E-mail: r.gonzalez@crya.unam.mx. THE RELATION BETWEEN DYNAMICS AND STAR FORMATION IN BARRED GALAXIES.  United States.  https://doi.org/10.1088/0004-637X/734/2/122

Copy to clipboard


                    Martinez-Garcia, Eric E, and Gonzalez-Lopezlira, Rosa A., E-mail: martinez@astroscu.unam.mx, E-mail: emartinez@cida.ve, E-mail: r.gonzalez@crya.unam.mx. 2011.  
        "THE RELATION BETWEEN DYNAMICS AND STAR FORMATION IN BARRED GALAXIES".  United States.  https://doi.org/10.1088/0004-637X/734/2/122.

Copy to clipboard


                    
@article{osti_21576592,

  title        = {THE RELATION BETWEEN DYNAMICS AND STAR FORMATION IN BARRED GALAXIES},

  author       = {Martinez-Garcia, Eric E and Gonzalez-Lopezlira, Rosa A., E-mail: martinez@astroscu.unam.mx, E-mail: emartinez@cida.ve, E-mail: r.gonzalez@crya.unam.mx},

  abstractNote = {We analyze optical and near-infrared data of a sample of 11 barred spiral galaxies, in order to establish a connection between star formation and bar/spiral dynamics. We find that 22 regions located in the bars and 20 regions in the spiral arms beyond the end of the bar present azimuthal color/age gradients that may be attributed to star formation triggering. Assuming a circular motion dynamic model, we compare the observed age gradient candidates with stellar population synthesis models. A link can then be established with the disk dynamics that allows us to obtain parameters like the pattern speed of the bar or spiral as well as the positions of resonance radii. We subsequently compare the derived pattern speeds with those expected from theoretical and observational results in the literature (e.g., bars ending near corotation). We find a tendency to overestimate bar pattern speeds derived from color gradients in the bar at small radii, away from corotation; this trend can be attributed to non-circular motions of the young stars born in the bar region. In spiral regions, we find that {approx}50% of the color gradient candidates are 'inverse', i.e., with the direction of stellar aging contrary to that of rotation. The other half of the gradients found in spiral arms have stellar ages that increase in the same sense as rotation. Of the nine objects with gradients in both bars and spirals, six (67%) appear to have a bar and a spiral with similar {Omega}{sub p}, while three (33%) do not.},

  doi          = {10.1088/0004-637X/734/2/122},

  url          = {https://www.osti.gov/biblio/21576592},
  journal      = {Astrophysical Journal},

  issn         = {0004-637X},

  number       = 2,

  volume       = 734,

  place        = {United States},

  year         = {Mon Jun 20 00:00:00 EDT 2011},

  month        = {Mon Jun 20 00:00:00 EDT 2011}

}

Copy to clipboard

Journal Article:

https://doi.org/10.1088/0004-637X/734/2/122

Other availability

Find in Google Scholar

Search WorldCat to find libraries that may hold this journal

Save / Share:

Export Metadata

Save to My Library

Similar records in OSTI.GOV collections:

EFFECTS OF NON-CIRCULAR MOTIONS ON AZIMUTHAL COLOR GRADIENTS

Journal Article Martinez-Garcia, Eric; Gonzalez-Lopezlira, Rosa - Astrophysical Journal

Assuming that density waves trigger star formation, and that young stars preserve the velocity components of the molecular gas where they are born, we analyze the effects that non-circular gas orbits have on color gradients across spiral arms. We try two approaches, one involving semianalytical solutions for spiral shocks, and another with magnetohydrodynamic (MHD) numerical simulation data. We find that, if non-circular motions are ignored, the comparison between observed color gradients and stellar population synthesis models would in principle yield pattern speed values that are systematically too high for regions inside corotation, with the difference between the real and themore »« less
https://doi.org/10.1088/0004-637X/707/2/1650
INTERPLAY BETWEEN STELLAR SPIRALS AND THE INTERSTELLAR MEDIUM IN GALACTIC DISKS

Journal Article Wada, Keiichi; Baba, Junichi - Astrophysical Journal

We propose a new dynamical picture of galactic stellar and gas spirals, based on hydrodynamic simulations in a 'live' stellar disk. We focus especially on spiral structures excited in an isolated galactic disk without a stellar bar. Using high-resolution, three-dimensional N-body/smoothed particle hydrodynamic simulations, we found that the spiral features of the gas in galactic disks are formed by essentially different mechanisms from the galactic shock in stellar density waves. The stellar spiral arms and the interstellar matter on average corotate in a galactic potential at any radii. Unlike the stream motions in the galactic shock, the interstellar matter flowsmore »« less
https://doi.org/10.1088/0004-637X/735/1/1
PATTERN SPEEDS OF BARS AND SPIRAL ARMS FROM Halpha VELOCITY FIELDS

Journal Article Fathi, K; Pinol-Ferrer, N; Beckman, J; ... - Astrophysical Journal

We have applied the Tremaine-Weinberg method to 10 late-type barred spiral galaxies using data cubes, in Halpha emission, from the FaNTOmM and GHAFAS Fabry-Perot spectrometers. We have combined the derived bar (and/or spiral) pattern speeds with angular frequency plots to measure the corotation radii for the bars in these galaxies. We base our results on a combination of this method with a morphological analysis designed to estimate the corotation radius to bar-length ratio using two independent techniques on archival near-infrared images, and although we are aware of the limitation of the application of the Tremaine-Weinberg method using Halpha observations, wemore »« less
https://doi.org/10.1088/0004-637X/704/2/1657
Testing density wave theory with resolved stellar populations around spiral arms in M81

Journal Article Choi, Yumi; Dalcanton, Julianne; Williams, Benjamin; ... - Astrophysical Journal

Stationary density waves rotating at a constant pattern speed Ω{sub P} would produce age gradients across spiral arms. We test whether such age gradients are present in M81 by deriving the recent star formation histories (SFHs) of 20 regions around one of M81's grand-design spiral arms. For each region, we use resolved stellar populations to determine the SFH by modeling the observed color–magnitude diagram constructed from archival Hubble Space Telescope F435W and F606W imaging. Although we should be able to detect systematic time delays in our spatially resolved SFHs, we find no evidence of star formation propagation across the spiralmore »« less
https://doi.org/10.1088/0004-637X/810/1/9
SIGNATURES OF LONG-LIVED SPIRAL PATTERNS

Journal Article Martinez-Garcia, Eric - Astrophysical Journal

Azimuthal age/color gradients across spiral arms are a signature of long-lived spirals. From a sample of 19 normal (or weakly barred) spirals where we have previously found azimuthal age/color gradient candidates, 13 objects were further selected if a two-armed grand-design pattern survived in a surface density stellar mass map. Mass maps were obtained from optical and near-infrared imaging, by comparison with a Monte Carlo library of stellar population synthesis models that allowed us to obtain the mass-to-light ratio in the J band, (M/L){sub J}, as a function of (g - i) versus (i - J) color. The selected spirals weremore »« less
https://doi.org/10.1088/0004-637X/765/2/105

Similar Records