Near-infrared imaging of FSC 10214+4724 with the W. M. Keck Telescope

Abstract

Near-infrared observations of the z = 2.286 IRAS source FSC 10214+4724, made with the near-infrared camera on t~e W. M. Keck Telescope, are reported. Deep broad-band images at 2.15 and 1.27 µm, and narrow-band images at 2.165 and 2.125 µm with 0':6 to 0''.9 seeing show that FSC 10214+4724 consists of at least t~ree distinct ~ompon~nts in a compact group of galaxies. The source of the infrared luminosity appears ~o be t~ a strongly mteractmg galaxy that has a luminosity ~ 100 times that of a present-day L * galaxy. The mteractton suggests an "age" of this galaxy of ~ 10 9 yr. The Hex emission is resolved as a source of diameter ~ 5 kpc, suggesting that a starburst contributes to the observed Hex emission. There is an excess of objects in the FSC 10214 + 4724 field that could represent galaxies in an associated cluster.

[ITAL]Hubble Space Telescope[/ITAL] Imaging Polarimetry of the Gravitational Lens FSC 10214+4724

“…Di †erent distributions for the UV and optical continuum regions can account for the appearances of FSC 10214]4724 at di †erent wavelengths noted by Matthews et al (1994). The lens model suggested by E96 and a source geometry as sketched in Figure 3 reproduce qualitatively the inferred lensing magniÐcation of 250, the observed arc morphology and the arc astrometry at F437M.…”

Molecular Gas at High Redshift

“…High-resolution optical and near-IR imaging (Broadhurst & Leh'ar 1995, Graham & Liu 1995, Matthews et al 1994 clearly show that F10214 is gravitation-ally lensed. The 2.2-µm image shows a compact 0.7 ′′ diameter source superposed on a weaker 1.5 ′′ arc.…”

3D: The next generation near-infrared imaging spectrometer

“…The spectrum has the highest spectral resolution so far (compare to Elston et al 1994) and not only clearly separates Hα and one [NII] line but shows indications of the [SII] and [OI] lines as well. The continuum map (sum of the continuum channels only) shows two other accompanying galaxies which also appear in the K s -band map of Matthews et al (1994) and Graham & Liu (1995). Our data do not reveal any strong K-band emission or absorption lines from these galaxies and their spectral energy distribution is consistent with those of early type elliptical galaxies at a redshift of z = 0.9 (Eisenhardt et al 1995).…”

“…A bolometric luminosity of L bol > 3 10 14 L (H 0 =50, Rowan-Robinson et al 1991) and a large mass of molecular gas (∼ 2 10 11 M , H 0 =100; Solomon et al 1992) has led to speculation that this source represents a true primeval galaxy in the process of forming the bulk of its stellar population and enriching its ISM with metals for the first time. However, the distorted arc-like appearance of F10214 in high resolution K-band images from the Keck telescope (Matthews et al 1994;Graham & Liu 1995) and in recent optical HST imaging (Eisenhardt et al 1995), the presence of companions, and statistical arguments makes it almost certain that F10214 is gravitationally lensed by a foreground object (Broadhurst & Lehár 1995;Eisenhardt et al 1995). Both UV as well as optical rest frame long slit spectroscopy of Elston et al (1994) shows characteristics of an AGN-type object.…”