TY - JOUR
T1 - Near-infrared integral field spectroscopy of star-forming galaxies
AU - Dale, Daniel A.
AU - Roussel, Hélène
AU - Contursi, Alessandra
AU - Helou, George
AU - Dinerstein, Harriet L.
AU - Hunter, Deidre A.
AU - Hollenbach, David J.
AU - Egami, Eiichi
AU - Matthews, Keith
AU - Murphy, Thomas W.
AU - Lafon, Christine E.
AU - Rubin, Robert H.
PY - 2004/2/1
Y1 - 2004/2/1
N2 - The Palomar Integral Field Spectrograph was used to probe a variety of environments in nine nearby galaxies that span a range of morphological types, luminosities, metallicities, and infrared-to-blue ratios. For the first time, near-infrared spectroscopy was obtained for nuclear or bright H II regions in star-forming galaxies over two spatial dimensions (5′.7 × 10′.0) in the [Fe II] (1.257 μm), [Fe II] (1.644 μm), Paβ (1.282 μm), H2 (2.122 μm), and Brγ (2.166 μm) transition lines. These data yield constraints on various characteristics of the star-forming episodes in these regions, including their strength, maturity, spatial variability, and extinction. The H II regions stand out from the nuclei. Unlike observations of nuclear regions, H II region near-infrared observations do not show a spatial coincidence of the line and continuum emission; the continuum and line maps of H II regions usually show distinct and sometimes spatially separated morphologies. Gauging from Paβ and Brγ equivalent widths and luminosities, the H II regions have younger episodes of star formation than the nuclei and more intense radiation fields. Near-infrared line ratio diagnostics suggest that H II regions have "purer" starbursting properties. The correlation between ionizing photon density and mid-infrared color is consistent with the star formation activity level being higher for H II regions than for nuclei. And though the interpretation is complicated, on a purely empirical basis the H II regions show lower Fe 1+ abundances than nuclei by an order of magnitude.
AB - The Palomar Integral Field Spectrograph was used to probe a variety of environments in nine nearby galaxies that span a range of morphological types, luminosities, metallicities, and infrared-to-blue ratios. For the first time, near-infrared spectroscopy was obtained for nuclear or bright H II regions in star-forming galaxies over two spatial dimensions (5′.7 × 10′.0) in the [Fe II] (1.257 μm), [Fe II] (1.644 μm), Paβ (1.282 μm), H2 (2.122 μm), and Brγ (2.166 μm) transition lines. These data yield constraints on various characteristics of the star-forming episodes in these regions, including their strength, maturity, spatial variability, and extinction. The H II regions stand out from the nuclei. Unlike observations of nuclear regions, H II region near-infrared observations do not show a spatial coincidence of the line and continuum emission; the continuum and line maps of H II regions usually show distinct and sometimes spatially separated morphologies. Gauging from Paβ and Brγ equivalent widths and luminosities, the H II regions have younger episodes of star formation than the nuclei and more intense radiation fields. Near-infrared line ratio diagnostics suggest that H II regions have "purer" starbursting properties. The correlation between ionizing photon density and mid-infrared color is consistent with the star formation activity level being higher for H II regions than for nuclei. And though the interpretation is complicated, on a purely empirical basis the H II regions show lower Fe 1+ abundances than nuclei by an order of magnitude.
KW - Galaxies: ISM
KW - H II regions
KW - Infrared: galaxies
KW - Stars: formation
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U2 - 10.1086/380753
DO - 10.1086/380753
M3 - Article
AN - SCOPUS:1842585533
VL - 601
SP - 813
EP - 830
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2 I
ER -