Showing papers by "Peter Eisenhardt published in 1994"
TL;DR: In this article, the rest-frame optical and UV spectra of the luminous, high redshift Infrared Astronomy Satellite (IRAS) source FSC 10214+4724 were analyzed and it was shown that the UV emission lines are similar to those attributed to Active Galactic Nuclei (AGN) rather than to star formation.
Abstract: We have observed the rest-frame optical and UV spectra of the luminous, high redshift Infrared Astronomy Satellite (IRAS) source FSC 10214+4724. We find the optical emission lines to be characterized by ratios similar to those found in Seyfert II galaxies. We support the conclusion of previous work that the UV emission lines are similar to those attributed to Active Galactic Nuclei (AGN) rather than to star formation. The ratio H alpha/H beta greater than or equal to 20 (2 sigma lower limit) implies substantial reddening of the narrow line region with A(sub V) greater than 5.5, sufficient to hide a broad line region in our H alpha observations. Given this large inferred reddening and the strength of the UV continuum and emission lines, we conclude (as have others) that simple screen models of reddening are not appropriate for this object. These properties are very similar to those of the infrared luminous galaxies at lower redshift, suggesting that FSC 10244+4724 is the luminous extreme of the same population. We also present H band (1.6 micrometer) imaging polarimetry observations and find that the rest-frame optical emission is unpolarized (P = 3.2% +/- 22.0%). This deep image of the field shows FSC 10214+4724 to possess an unresolved core, with several companions located within 10 sec of the point source. We find it unlikely that this group of objects is physically associated with FSC 10214+4724 at z = 2.3, and we argue that their magnitudes and colors are more consistant with those expected with those expected for galaxies in a foreground group. While galaxy number counts would suggest that such a projection has a low probability of being observed randomly, a foreground group might gravitational lens the z = 2.3 source, making such random statistics inappropriate, and contribute to the large observed luminosity of FSC 10214+4724. Comparison of H band images taken on two occasions one year apart show that FSC 10214+4724 had varied by 0.16 +/- 0.03 mag relative to a nearby star during that time. The UV-optical emission line spectra, the bright dereddened continuum magnitude (K less than 12) of the unresolved core, its extremely large bolometric luminosity, strong UV polarization, and possible variability all suggest that FSC 10214+4724 harbors an obscured AGN. Given that we observe no spectral features attributable to star formation, it appears either that star formation in FSC 10214+4724 is more highly obscured at optical and UV wavelengths than the narrow line region of the AGN, or that the AGN (rather than star formation) dominates the large luminosity of this object.
42 citations
TL;DR: The Space Infrared Telescope Facility (SIRTF) as discussed by the authors is the first space observatory to make extensive use of the powerful infrared detector array technology discussed at this conference and is scheduled for launch early in the next decade.
Abstract: This paper describes the status of NASA’s Space Infrared Telescope Facility (SIRTF) program. SIRTF will be a cryogenically cooled observatory for infrared astronomy from space and is planned for launch early in the next decade. It will be the first cryogenic space observatory to make extensive use of the powerful infrared detector array technology discussed at this conference. We summarize a newly developed SIRTF mission concept and show how the availability of detector arrays has shaped the scientific rationale for SIRTF, and how the arrays themselves have become part of the definition of the SIRTF mission.
01 Jan 1994
TL;DR: In this paper, the first results of an IR imaging program to study galaxy evolution in moderate redshift galaxy clusters were presented, and the results showed that the evolution of galaxy clusters in moderate REDSTREAM clusters is well studied.
Abstract: We present the first results of an IR imaging program to study galaxy evolution in moderate redshift galaxy clusters.
01 Jan 1994
TL;DR: In this article, the authors search for redshifted optical emission lines in the near-infrared from 17 distant radio galaxies (and the IRAS source FSC 10214+4724, Eiston et al. 1993), using InSb array spectrometers at the KPNO and CTIO 4m telescopes.
Abstract: We have searched for redshifted optical emission lines in the near-infrared from 17 distant radio galaxies (and the IRAS source FSC 10214+4724, Eiston et al. 1993), using InSb array spectrometers at the KPNO and CTIO 4m telescopes. The redshifts range from 0.8 to 3.4. We detect lines in over a dozen cases, summarized in the table below.