Prof. Dimitra Rigopoulou: Publications

ISO spectroscopy of ultraluminous infrared galaxies

ASTROPHYS SPACE SCI 266:1-2 (1999) 85-90

Authors:

D Lutz, R Genzel, D Kunze, D Rigopoulou, HWW Spoon, E Sturm, D Tran, AFM Moorwood

Abstract:

Spectroscopy from the Infrared Space Observatory ISO has for the first time provided the sensitivity to exploit the diagnostic power of mid-infrared fine structure lines and PAH features for the study of ultraluminous infrared galaxies (L-IR > 10(12)L.). We report on observations obtained with SWS, ISOPHOT-S, and the CVF option of ISOCAM. From both fine structure lines and PAH features, we find that the majority of ULIRGs is predominantly powered by star formation. Our total sample of about 75 ULIRGs allows to search for trends within the class of ULIRGs: The fraction of AGNs increases with luminosity above similar to 3 x 10(12)L. but there is no obvious trend for ULIRGs to be more AGN-like with more advanced merger phase.

ISO spectroscopy of nearby starburst galaxies

IAU SYMP (1999) 745-746

Authors:

D Kunze, D Lutz, D Rigopoulou, MD Thornley, R Genzel

Abstract:

We present spectroscopic mid-IR observations of prominent starburst galaxies obtained with the short wavelength spectrometer onboard the Infrared Space Observatory. The wavelength range accessible by ISO-sws (2.5-45 pm) contains a large number of emission lines of atomic and molecular hydrogen and several other atomic species. In this paper we discuss the interpretation of the [NeIII] 15.5 mum/[NeII] 12.8 mum line-ratio, the faint [OIV] 25.9 mum line and the pure rotational lines of molecular hydrogen observed in our target galaxies.

Morphology and evolution of ultraluminous IR galaxies

ASTROPHYSICS AND SPACE SCIENCE 269 (1999) 399-402

Authors:

E Sturm, R Genzel, D Lutz, D Rigopoulou, D Tran, H Dannerbauer, AFM Moorwood, HWW Spoon

Proposed identification of Hubble Deep Field submillimeter source HDF 850.1

ASTRONOMY & ASTROPHYSICS 347:3 (1999) 809-820

Authors:

D Downes, R Neri, A Greve, S Guilloteau, F Casoli, D Hughes, D Lutz, KM Menten, DJ Wilner, P Andreani, F Bertoldi, CL Carilli, J Dunlop, R Genzel, F Gueth, RJ Ivison, RG Mann, Y Mellier, S Oliver, J Peacock, D Rigopoulou, M Rowan-Robinson, P Schilke, S Serjeant, LJ Tacconi, M Wright

The ISO-SWS survey of molecular hydrogen lines in active galaxies

ESA SP PUBL 427 (1999) 909-912

Authors:

D Kunze, D Rigopoulou, R Genzel, D Lutz

Abstract:

We present a survey of molecular hydrogen line emission in nearby starburst and Seyfert galaxies. Excitation temperatures and gas masses for loci-lying energy levels of Hz are derived from the observed pure rotational lines. The H-2 (0-0) S(1) line in Seyferts is emitted by a "warm" gas at temperature of 120-140 K. This component accounts for 0.2-20 per cent of the total gas content. In starbursts the temperature of the S(1) emitting gas is somewhat higher (up to 210 K) and contributes typically a few per cent to the total gas mass (up to 9 per cent in M82). The S(5) and S(7) lines trace a "hotter" gas component at temperatures of about 1100K (up to 1700K in IC342) both in Seyfert and starburst galaxies. The excitation of the molecular hydrogen in starbursts and some of the Seyfert galaxies is dominated by UV-fluorescence. However it cannot be excluded that a part of the "warm" H-2 gas is thermally excited. For some of the Seyferts indications for shock excitation are found.

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