Comparison of the Hα Equivalent Width of H II Regions in a Flocculent and a Grand-Design Galaxy: Possible Evidence for Initial Mass Function Variations

Bibcode
2005ApJ...634.1043C
DOI
10.1086/497116
Cedrés, Bernabé; Cepa, Jordi; Tomita, Akihiko
Bibliographical reference

The Astrophysical Journal, Volume 634, Issue 2, pp. 1043-1055.

Advertised on:
12
2005
Journal
The Astrophysical Journal
Number of authors
3
IAC number of authors
2
Citations
10
Refereed citations
10
Description
We present here a study of the Hα equivalent widths of the flocculent galaxy NGC 4395 and the grand-design galaxy NGC 5457. A difference between the mean values of the Hα equivalent widths for the two galaxies has been found. Several hypotheses are presented in order to explain this difference: differences in age, metallicity, star formation rate, photon leakage, and initial mass function. Various tests and Monte Carlo models are used to find out the most probable cause of this difference. The results show that the possible cause for the difference could be a variation in the initial mass function. This difference is such that it seems to favor a fraction of more massive stars in the grand-design galaxy when compared with the flocculent galaxy. This could be due to a change of the environmental conditions due to a density wave.
Type
Refereed
Galaxies
H II regions

It may interest you

  • Refereed
    Euclid preparation. XXXVI. Modelling the weak lensing angular power spectrum

    This work considers which higher order modeling effects on the cosmic shear angular power spectra must be taken into account for Euclid. We identified the relevant terms and quantified their individual and cumulative impact on the cosmological parameter inferences from Euclid. We computed the values of these higher order effects using analytic

    Euclid Collaboration et al.

    Advertised on:

    4
    2024
    Bibcode
    2024A&A...684A.138E
    Citations
    4
  • Refereed
    The discovery space of ELT-ANDES. Stars and stellar populations

    The ArmazoNes high Dispersion Echelle Spectrograph (ANDES) is the optical and near-infrared high-resolution echelle spectrograph envisioned for the Extremely Large Telescope (ELT). We present a selection of science cases, supported by new calculations and simulations, where ANDES could enable major advances in the fields of stars and stellar

    Roederer, Ian U. et al.

    Advertised on:

    4
    2024
    Bibcode
    2024ExA....57...17R
    Citations
    0
  • Refereed
    Euclid preparation. XXXVII. Galaxy colour selections with Euclid and ground photometry for cluster weak-lensing analyses

    Aims: We derived galaxy colour selections from Euclid and ground-based photometry, aiming to accurately define background galaxy samples in cluster weak-lensing analyses. These selections have been implemented in the Euclid data analysis pipelines for galaxy clusters. Methods: Given any set of photometric bands, we developed a method for the

    Euclid Collaboration et al.

    Advertised on:

    4
    2024
    Bibcode
    2024A&A...684A.139E
    Citations
    2