NICMOS Imaging of Infrared-Luminous Galaxies

摘要: We present near-infrared images obtained with the Hubble Space Telescope NICMOS camera for a sample of nine luminous [LIGs: LIR(8?1000 ?m) ? 1011 L?] and 15 ultraluminous (ULIGS: LIR 1012 L?) infrared galaxies. The includes representative systems classified as warm (f25 ?m/f60 ?m > 0.2) cold based on mid-infrared colors nuclear emission lines H II (i.e., starburst), QSO, Seyfert, LINER. morphologies galaxies are diverse provide further support idea that they created by collision or interactions spiral Although no new nuclei seen in images, do reveal structures, bridges, circumnuclear star clusters. luminosities observed clusters consistent them being young (107?108 yr), formed result galactic interactions, having masses much greater than those Galactic globular In NGC 6090 VV 114, preferentially situated along area overlap two disks. With exception IR 17208-0018, all ULIGs have at least one compact (2.2??m FWHM 200 pc) nucleus. Analysis m1.1?1.6 vs. m1.6?2.2) derived from 11 diameter apertures suggests QSO+hot dust galaxies, group, reddened starlight. addition, ULIG UGC 5101 (and possibly three others) suggesting additional active nucleus?like components their nuclei. 2 kpc aperture measurement, global except starlight few magnitudes visual extinction. general dichotomy properties supported light distributions: seven eight unresolved contributes significantly ?30%?40%) to total luminosity. smooth, more extended is most likely composed giant supergiant stars, but evidence longer wavelengths these stars contribute little high 8?1000 luminosity Finally, profiles 24 were fitted well an r1/4 law not so exponential disk profile). Whether eventually become massive central bulges elliptical will depend how efficiently ISM converted into stars.