| Issue |
EAS Publications Series
Volume 31, 2008
Far-Infrared Workshop 2007
|
|
|---|---|---|
| Page(s) | 93 - 96 | |
| DOI | https://doi.org/10.1051/eas:0831019 | |
| Published online | 04 October 2008 | |
C. Kramer, S. Aalto and R. Simon (eds)
EAS Publications Series, 31 (2008) 93-96
Nobeyama millimeter array observations of luminous infrared galaxies
1
National Astronomical Observatory of
Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588, Japan
2
Department of Astronomy, School of Science, Graduate University for
Advanced Studies, Mitaka, Tokyo 181-8588, Japan
We present the results of systematic millimeter interferometric observations of luminous infrared galaxies (LIRGs), using the Nobeyama Millimeter Array. We observed HCN (J = 1–0) and HCO+ (J = 1–0) emission lines simultaneously, and derived their brightness-temperature ratios, to investigate whether the observed ratios are similar to those found in AGN-dominated nuclei or starburst galaxies. LIRGs with (without) luminous buried AGN signatures in our infrared spectra tend to show high (low) HCN (J = 1–0) to HCO+ (J = 1–0) brightness-temperature ratios as seen in galaxy nuclei dominated by AGNs (starbursts). The high ratios in buried AGN candidates could be explained by the enhanced HCN abundance, and/or infrared radiative pumping of the HCN molecule, in the close vicinity of an AGN.
© EAS, EDP Sciences, 2008