Advanced search
1 file | 2.21 MB Add to list

The spatially resolved correlation between [NII] 205 µm line emission and the 24 µm continuum in nearby galaxies

Author
Organization
Abstract
A correlation between the 24 mu m continuum and the [NII] 205 mu m line emission may arise if both quantities trace the star formation activity on spatially-resolved scales within a galaxy, yet has so far only been observed in the nearby edge-on spiral galaxy NGC 891. We therefore assess whether the [NII] 205-24 mu m emission correlation has some physical origin or is merely an artefact of line-of sight projection effects in an edge-on disc. We search for the presence of a correlation in Herschel and Spitzer observations of two nearby face-on galaxies, M51 and M83, and the interacting Antennae galaxies NGC 4038 and 4039. We show that not only is this empirical relationship also observed in face-on galaxies, but also that the correlation appears to be governed by the star formation rate (SFR). Both the nuclear starburst in M83 and the merger-induced star formation in NGC 4038/9 exhibit less [NII] emission per unit SFR surface density than the normal star-forming discs. These regions of intense star formation exhibit stronger ionization parameters, as traced by the 70/160 mu m far-infrared (FIR) colour. These observations suggest the presence of higher ionization lines that may become more important for gas cooling, thereby reducing the observed [NII] 205 mu m line emission in regions with higher star formation rates. Finally, we present a general relation between the [NII] 205 mu m line flux density and SFR density for normal star-forming galaxies, yet note that future studies should extend this analysis by including observations with wider spatial coverage for a larger sample of galaxies.
Keywords
galaxies: star formation, galaxies: spiral, galaxies: ISM, infrared: galaxies, ISM: lines and bands, STAR-FORMATION RATE, MULTIBAND IMAGING PHOTOMETER, ULTRALUMINOUS INFRARED GALAXIES, FORMATION RATE INDICATORS, FORMATION RATES, C II, MOLECULAR GAS, CARINA NEBULA, NGC 4038/39, SPACE

Downloads

  • Hughes et al. 2016.pdf
    • full text
    • |
    • open access
    • |
    • PDF
    • |
    • 2.21 MB

Citation

Please use this url to cite or link to this publication:

MLA
Hughes, Thomas et al. “The Spatially Resolved Correlation Between [NII] 205 Μm Line Emission and the 24 Μm Continuum in Nearby Galaxies.” ASTRONOMY & ASTROPHYSICS 587 (2016): n. pag. Print.
APA
Hughes, Thomas, Baes, M., Schirm, M., Parkin, T., Wu, R., De Looze, I., Wilson, C., et al. (2016). The spatially resolved correlation between [NII] 205 µm line emission and the 24 µm continuum in nearby galaxies. ASTRONOMY & ASTROPHYSICS, 587.
Chicago author-date
Hughes, Thomas, Maarten Baes, MRP Schirm, TJ Parkin, R Wu, Ilse De Looze, CD Wilson, et al. 2016. “The Spatially Resolved Correlation Between [NII] 205 Μm Line Emission and the 24 Μm Continuum in Nearby Galaxies.” Astronomy & Astrophysics 587.
Chicago author-date (all authors)
Hughes, Thomas, Maarten Baes, MRP Schirm, TJ Parkin, R Wu, Ilse De Looze, CD Wilson, Sébastien Viaene, GJ Bendo, A Boselli, D Cormier, E Ibar, OŁ Karczewski, N Lu, and L Spinoglio. 2016. “The Spatially Resolved Correlation Between [NII] 205 Μm Line Emission and the 24 Μm Continuum in Nearby Galaxies.” Astronomy & Astrophysics 587.
Vancouver
1.
Hughes T, Baes M, Schirm M, Parkin T, Wu R, De Looze I, et al. The spatially resolved correlation between [NII] 205 µm line emission and the 24 µm continuum in nearby galaxies. ASTRONOMY & ASTROPHYSICS. 2016;587.
IEEE
[1]
T. Hughes et al., “The spatially resolved correlation between [NII] 205 µm line emission and the 24 µm continuum in nearby galaxies,” ASTRONOMY & ASTROPHYSICS, vol. 587, 2016.
@article{8096950,
  abstract     = {A correlation between the 24 mu m continuum and the [NII] 205 mu m line emission may arise if both quantities trace the star formation activity on spatially-resolved scales within a galaxy, yet has so far only been observed in the nearby edge-on spiral galaxy NGC 891. We therefore assess whether the [NII] 205-24 mu m emission correlation has some physical origin or is merely an artefact of line-of sight projection effects in an edge-on disc. We search for the presence of a correlation in Herschel and Spitzer observations of two nearby face-on galaxies, M51 and M83, and the interacting Antennae galaxies NGC 4038 and 4039. We show that not only is this empirical relationship also observed in face-on galaxies, but also that the correlation appears to be governed by the star formation rate (SFR). Both the nuclear starburst in M83 and the merger-induced star formation in NGC 4038/9 exhibit less [NII] emission per unit SFR surface density than the normal star-forming discs. These regions of intense star formation exhibit stronger ionization parameters, as traced by the 70/160 mu m far-infrared (FIR) colour. These observations suggest the presence of higher ionization lines that may become more important for gas cooling, thereby reducing the observed [NII] 205 mu m line emission in regions with higher star formation rates. Finally, we present a general relation between the [NII] 205 mu m line flux density and SFR density for normal star-forming galaxies, yet note that future studies should extend this analysis by including observations with wider spatial coverage for a larger sample of galaxies.},
  articleno    = {A45},
  author       = {Hughes, Thomas and Baes, Maarten and Schirm, MRP and Parkin, TJ and Wu, R and De Looze, Ilse and Wilson, CD and Viaene, Sébastien and Bendo, GJ and Boselli, A and Cormier, D and Ibar, E and Karczewski, OŁ and Lu, N and Spinoglio, L},
  issn         = {1432-0746},
  journal      = {ASTRONOMY & ASTROPHYSICS},
  keywords     = {galaxies: star formation,galaxies: spiral,galaxies: ISM,infrared: galaxies,ISM: lines and bands,STAR-FORMATION RATE,MULTIBAND IMAGING PHOTOMETER,ULTRALUMINOUS INFRARED GALAXIES,FORMATION RATE INDICATORS,FORMATION RATES,C II,MOLECULAR GAS,CARINA NEBULA,NGC 4038/39,SPACE},
  language     = {eng},
  pages        = {7},
  title        = {The spatially resolved correlation between [NII] 205 µm line emission and the 24 µm continuum in nearby galaxies},
  url          = {http://dx.doi.org/10.1051/0004-6361/201527644},
  volume       = {587},
  year         = {2016},
}

Altmetric
View in Altmetric
Web of Science
Times cited: