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Title: TWO RAPIDLY VARIABLE GALACTIC X-RAY TRANSIENTS OBSERVED WITH CHANDRA, XMM-NEWTON, AND SUZAKU

Abstract

We have identified two moderately bright, rapidly variable transients in new and archival X-ray data near the Galactic center. Both objects show strong, flaring variability on timescales of tens to thousands of seconds, evidence of N{sub H} variability, and hard spectra. XMMU J174445.5-295044 is seen at 2-10 keV fluxes of 3 x 10{sup -11} to <10{sup -12} erg cm{sup -2} s{sup -1}, with N{sub H} at or above 5 x 10{sup 22} cm{sup -2}, by XMM-Newton, Chandra, and Suzaku. A likely Two Micron All Sky Survey (2MASS) counterpart with K{sub S} = 10.2 shows colors indicative of a late-type star. CXOU J174042.0-280724 is a likely counterpart to the fast hard transient IGR J17407-2808. Chandra observations find F{sub X} (2-10 keV) {approx}10{sup -12} erg cm{sup -2} s{sup -1}, with large N{sub H} variations (from 2 x 10{sup 22} to >2 x 10{sup 23} cm{sup -2}). No 2MASS counterpart is visible, to K{sub S} >13. XMMU J174445.5-295044 seems likely to be a new symbiotic star or symbiotic X-ray binary, while CXOU J174042.0-280724 is more mysterious, likely an unusual low-mass X-ray binary.

Authors:
 [1];  [2];  [3]
  1. University of Alberta, Department of Physics, Room 238 CEB, 11322-89 Avenue, Edmonton, AB T6G 2G7 (Canada)
  2. Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States)
  3. Northwestern University, Department of Physics and Astronomy, 2145 Sheridan Road, Evanston, IL 60208 (United States)
Publication Date:
OSTI Identifier:
21319553
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 701; Journal Issue: 2; Other Information: DOI: 10.1088/0004-637X/701/2/1627; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BINARY STARS; COSMIC X-RAY SOURCES; FLARING; KEV RANGE 01-10; MASS; NEUTRONS; SYMBIOTIC STARS

Citation Formats

Heinke, C O, Tomsick, J A, Yusef-Zadeh, F, and Grindlay, J. E. TWO RAPIDLY VARIABLE GALACTIC X-RAY TRANSIENTS OBSERVED WITH CHANDRA, XMM-NEWTON, AND SUZAKU. United States: N. p., 2009. Web. doi:10.1088/0004-637X/701/2/1627; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
Heinke, C O, Tomsick, J A, Yusef-Zadeh, F, & Grindlay, J. E. TWO RAPIDLY VARIABLE GALACTIC X-RAY TRANSIENTS OBSERVED WITH CHANDRA, XMM-NEWTON, AND SUZAKU. United States. https://doi.org/10.1088/0004-637X/701/2/1627; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)
Heinke, C O, Tomsick, J A, Yusef-Zadeh, F, and Grindlay, J. E. 2009. "TWO RAPIDLY VARIABLE GALACTIC X-RAY TRANSIENTS OBSERVED WITH CHANDRA, XMM-NEWTON, AND SUZAKU". United States. https://doi.org/10.1088/0004-637X/701/2/1627; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
@article{osti_21319553,
title = {TWO RAPIDLY VARIABLE GALACTIC X-RAY TRANSIENTS OBSERVED WITH CHANDRA, XMM-NEWTON, AND SUZAKU},
author = {Heinke, C O and Tomsick, J A and Yusef-Zadeh, F and Grindlay, J. E.},
abstractNote = {We have identified two moderately bright, rapidly variable transients in new and archival X-ray data near the Galactic center. Both objects show strong, flaring variability on timescales of tens to thousands of seconds, evidence of N{sub H} variability, and hard spectra. XMMU J174445.5-295044 is seen at 2-10 keV fluxes of 3 x 10{sup -11} to <10{sup -12} erg cm{sup -2} s{sup -1}, with N{sub H} at or above 5 x 10{sup 22} cm{sup -2}, by XMM-Newton, Chandra, and Suzaku. A likely Two Micron All Sky Survey (2MASS) counterpart with K{sub S} = 10.2 shows colors indicative of a late-type star. CXOU J174042.0-280724 is a likely counterpart to the fast hard transient IGR J17407-2808. Chandra observations find F{sub X} (2-10 keV) {approx}10{sup -12} erg cm{sup -2} s{sup -1}, with large N{sub H} variations (from 2 x 10{sup 22} to >2 x 10{sup 23} cm{sup -2}). No 2MASS counterpart is visible, to K{sub S} >13. XMMU J174445.5-295044 seems likely to be a new symbiotic star or symbiotic X-ray binary, while CXOU J174042.0-280724 is more mysterious, likely an unusual low-mass X-ray binary.},
doi = {10.1088/0004-637X/701/2/1627; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)},
url = {https://www.osti.gov/biblio/21319553}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 701,
place = {United States},
year = {Thu Aug 20 00:00:00 EDT 2009},
month = {Thu Aug 20 00:00:00 EDT 2009}
}