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Title: AN ADAPTIVE OPTICS SURVEY FOR CLOSE PROTOSTELLAR BINARIES

Abstract

In order to test the hypothesis that Class I protostellar binary stars are a product of ejections during the dynamical decay of nonhierarchical multiple systems, we combined the results of new adaptive optics (AO) observations of Class I protostars with our previously published AO data to investigate whether Class I protostars with a widely separated companion (r > 200 AU) are more likely to also have a close companion (r < 200 AU). In total, we observed 47 embedded young stellar objects (YSOs) with either the Subaru natural guide star AO system or the Keck laser guide star AO system. We found that targets with a widely separated companion within 5000 AU are not more likely to have a close companion. However, targets with another YSO within a projected separation of 25,000 AU are much more likely to have a close companion. Most importantly, every target with a close companion has another YSO within a projected separation of 25,000 AU. We came to the same conclusions after considering a restricted sample of targets within 500 pc and close companions wider than 50 AU to minimize incompleteness effects. The Orion star-forming region was found to have an excess of both closemore » binaries and YSOs within 25,000 AU compared to other star-forming regions. We interpret these observations as strong evidence that many close Class I binary stars form via ejections and that many of the ejected stars become unbound during the Class I phase.« less

Authors:
 [1];  [2];  [3]
  1. NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035 (United States)
  2. University of Hawaii, Institute for Astronomy, 640 N. Aohoku Pl., Hilo, HI 96720 (United States)
  3. University of Hawaii, Institute for Astronomy, 2680 Woodlawn Dr., Honolulu, HI 96822 (United States)
Publication Date:
OSTI Identifier:
21301581
Resource Type:
Journal Article
Journal Name:
Astronomical Journal (New York, N.Y. Online)
Additional Journal Information:
Journal Volume: 138; Journal Issue: 5; Other Information: DOI: 10.1088/0004-6256/138/5/1193; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1538-3881
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; 99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; BINARY STARS; HYPOTHESIS; LASERS; OPTICS; PROTOSTARS

Citation Formats

Connelley, Michael S, Reipurth, Bo, and Tokunaga, Alan T. AN ADAPTIVE OPTICS SURVEY FOR CLOSE PROTOSTELLAR BINARIES. United States: N. p., 2009. Web. doi:10.1088/0004-6256/138/5/1193; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
Connelley, Michael S, Reipurth, Bo, & Tokunaga, Alan T. AN ADAPTIVE OPTICS SURVEY FOR CLOSE PROTOSTELLAR BINARIES. United States. https://doi.org/10.1088/0004-6256/138/5/1193; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)
Connelley, Michael S, Reipurth, Bo, and Tokunaga, Alan T. 2009. "AN ADAPTIVE OPTICS SURVEY FOR CLOSE PROTOSTELLAR BINARIES". United States. https://doi.org/10.1088/0004-6256/138/5/1193; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
@article{osti_21301581,
title = {AN ADAPTIVE OPTICS SURVEY FOR CLOSE PROTOSTELLAR BINARIES},
author = {Connelley, Michael S and Reipurth, Bo and Tokunaga, Alan T},
abstractNote = {In order to test the hypothesis that Class I protostellar binary stars are a product of ejections during the dynamical decay of nonhierarchical multiple systems, we combined the results of new adaptive optics (AO) observations of Class I protostars with our previously published AO data to investigate whether Class I protostars with a widely separated companion (r > 200 AU) are more likely to also have a close companion (r < 200 AU). In total, we observed 47 embedded young stellar objects (YSOs) with either the Subaru natural guide star AO system or the Keck laser guide star AO system. We found that targets with a widely separated companion within 5000 AU are not more likely to have a close companion. However, targets with another YSO within a projected separation of 25,000 AU are much more likely to have a close companion. Most importantly, every target with a close companion has another YSO within a projected separation of 25,000 AU. We came to the same conclusions after considering a restricted sample of targets within 500 pc and close companions wider than 50 AU to minimize incompleteness effects. The Orion star-forming region was found to have an excess of both close binaries and YSOs within 25,000 AU compared to other star-forming regions. We interpret these observations as strong evidence that many close Class I binary stars form via ejections and that many of the ejected stars become unbound during the Class I phase.},
doi = {10.1088/0004-6256/138/5/1193; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)},
url = {https://www.osti.gov/biblio/21301581}, journal = {Astronomical Journal (New York, N.Y. Online)},
issn = {1538-3881},
number = 5,
volume = 138,
place = {United States},
year = {Sun Nov 15 00:00:00 EST 2009},
month = {Sun Nov 15 00:00:00 EST 2009}
}