The Nuclear Near-Infrared Spectral Properties of Nearby Galaxies

Mason, R. E.; Rodríguez-Ardila, A.; Martins, L.; Riffel, R.; González Martín, O.; Ramos Almeida, C.; Ruschel Dutra, D.; Ho, L. C.; Thanjavur, K.; Flohic, H.; Alonso-Herrero, A.; Lira, P.; McDermid, R.; Riffel, R. A.; Schiavon, R. P.; Winge, C.; Hoenig, M. D.; Perlman, E.
Referencia bibliográfica

The Astrophysical Journal Supplement Series, Volume 217, Issue 1, article id. 13, 27 pp. (2015).

Fecha de publicación:
3
2015
Número de autores
18
Número de autores del IAC
3
Número de citas
60
Número de citas referidas
57
Descripción
We present spectra of the nuclear regions of 50 nearby (D = 1-92 Mpc, median = 20 Mpc) galaxies of morphological types E to Sm. The spectra, obtained with the Gemini Near-IR Spectrograph on the Gemini North telescope, cover a wavelength range of approximately 0.85-2.5 μm at R ˜ 1300-1800. There is evidence that most of the galaxies host an active galactic nucleus (AGN), but the range of AGN luminosities (log (L 2-10 keV [erg s-1]) = 37.0-43.2) in the sample means that the spectra display a wide variety of features. Some nuclei, especially the Seyferts, exhibit a rich emission-line spectrum. Other objects, in particular the type 2 Low Ionization Nuclear Emission Region galaxies, show just a few, weak emission lines, allowing a detailed view of the underlying stellar population. These spectra display numerous absorption features sensitive to the stellar initial mass function, as well as molecular bands arising in cool stars, and many other atomic absorption lines. We compare the spectra of subsets of galaxies known to be characterized by intermediate-age and old stellar populations, and find clear differences in their absorption lines and continuum shapes. We also examine the effect of atmospheric water vapor on the signal-to-noise ratio achieved in regions between the conventional NIR atmospheric windows, which are of potential interest to those planning observations of redshifted emission lines or other features affected by telluric H2O. Further exploitation of this data set is in progress, and the reduced spectra and data reduction tools are made available to the community.
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