The Einstein Observatory Extended Medium-Sensitivity Survey. II - The optical identifications

Journal Article · Mon Jul 01 04:00:00 EDT 1991 · Astrophysical Journal, Supplement Series; (United States)

DOI:https://doi.org/10.1086/191582· OSTI ID:5258939

Stocke, J T; Morris, S L; Gioia, I M; Maccacaro, T; Schild, R ^[1]

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1. Colorado, University, Boulder (USA) Observatories of the Carnegie Institution of Washington, Pasadena, CA (USA) Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (USA)

The optical identifications are presented of the Einstein Extended Medium-Sensitivity Survey (EMSS), including the methodology used to optically identify the EMSS sources and the uncertainties involved with that process. The optical properties of the classes of X-ray, optical, and radio data for each of the identified and, as yet, unidentified sources of the survey are described. A new class of X-ray emitters, cooling flow galaxies, is proposed. The criteria used to determine whether the proposed optical counterpart to the X-ray source is a plausible identification are described. Plausibility is based on the optical classification of the counterpart, e.g., AGN, cluster, G star, and the X-ray-to-optical flux ratios previously observed for these classes of X-ray emitters. Two independent schemes of optical classification of the counterparts are used to check the plausibility of these identifications; one is based on moderate-resolution optical spectroscopy, and the other, on inferred X-ray luminosity and the overall energy distribution. 110 refs.

• OSTI ID: 5258939
• Journal Information: Astrophysical Journal, Supplement Series; (United States), Journal Name: Astrophysical Journal, Supplement Series; (United States) Vol. 76; ISSN APJSA; ISSN 0067-0049
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
640105 -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BL LACERTAE OBJECTS
COOLING
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
ELECTROMAGNETIC RADIATION
FLUID FLOW
GALAXY CLUSTERS
GALAXY NUCLEI
GAS FLOW
IDENTIFICATION SYSTEMS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
QUASARS
RADIATIONS
SURVEYS
VISIBLE RADIATION