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Title: A CHANDRA X-RAY OBSERVATORY STUDY OF PSR J1740-5340 AND CANDIDATE MILLISECOND PULSARS IN THE GLOBULAR CLUSTER NGC 6397

Abstract

We present a deep Chandra X-ray Observatory study of the peculiar binary radio millisecond pulsar (MSP) PSR J1740-5340 and candidate millisecond pulsars in the globular cluster NGC 6397. The X-rays from PSR J1740-5340 appear to be non-thermal and exhibit variability at the binary period. These properties suggest the presence of a relativistic intrabinary shock formed due to interaction of a relativistic rotation-powered pulsar wind and outflow from the unusual 'red-straggler/sub-subgiant' companion. We find the X-ray source U18 to show similar X-ray and optical properties to those of PSR J1740-5340, making it a strong MSP candidate. It exhibits variability on timescales from hours to years, also consistent with an intrabinary shock origin of its X-ray emission. The unprecedented depth of the X-ray data allows us to conduct a complete census of MSPs in NGC 6397. Based on the properties of the present sample of X-ray-detected MSPs in the Galaxy, we find that NGC 6397 probably hosts no more than six MSPs.

Authors:
 [1]; ;  [2];  [3]; ;  [4]
  1. Department of Physics, McGill University, 3600 University Street, Montreal, PQ H3A 2T8 (Canada)
  2. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
  3. Department of Physics, University of Alberta, Edmonton, AB T6G 2G7 (Canada)
  4. Department of Astronomy, Indiana University, 727 East Third Street, Bloomington, IN 47405 (United States)
Publication Date:
OSTI Identifier:
21392344
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 709; Journal Issue: 1; Other Information: DOI: 10.1088/0004-637X/709/1/241; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; EMISSION; GALAXIES; NEUTRON STARS; NEUTRONS; OPTICAL PROPERTIES; PULSARS; RELATIVISTIC RANGE; ROTATION; X RADIATION; BARYONS; COSMIC RADIO SOURCES; ELECTROMAGNETIC RADIATION; ELEMENTARY PARTICLES; ENERGY RANGE; FERMIONS; HADRONS; IONIZING RADIATIONS; MOTION; NUCLEONS; PHYSICAL PROPERTIES; RADIATIONS; STARS

Citation Formats

Bogdanov, Slavko, Van den Berg, Maureen, Grindlay, Jonathan E., Heinke, Craig O., Cohn, Haldan N., and Lugger, Phyllis M., E-mail: bogdanov@physics.mcgill.c. A CHANDRA X-RAY OBSERVATORY STUDY OF PSR J1740-5340 AND CANDIDATE MILLISECOND PULSARS IN THE GLOBULAR CLUSTER NGC 6397. United States: N. p., 2010. Web. doi:10.1088/0004-637X/709/1/241.
Bogdanov, Slavko, Van den Berg, Maureen, Grindlay, Jonathan E., Heinke, Craig O., Cohn, Haldan N., & Lugger, Phyllis M., E-mail: bogdanov@physics.mcgill.c. A CHANDRA X-RAY OBSERVATORY STUDY OF PSR J1740-5340 AND CANDIDATE MILLISECOND PULSARS IN THE GLOBULAR CLUSTER NGC 6397. United States. doi:10.1088/0004-637X/709/1/241.
Bogdanov, Slavko, Van den Berg, Maureen, Grindlay, Jonathan E., Heinke, Craig O., Cohn, Haldan N., and Lugger, Phyllis M., E-mail: bogdanov@physics.mcgill.c. Wed . "A CHANDRA X-RAY OBSERVATORY STUDY OF PSR J1740-5340 AND CANDIDATE MILLISECOND PULSARS IN THE GLOBULAR CLUSTER NGC 6397". United States. doi:10.1088/0004-637X/709/1/241.
@article{osti_21392344,
title = {A CHANDRA X-RAY OBSERVATORY STUDY OF PSR J1740-5340 AND CANDIDATE MILLISECOND PULSARS IN THE GLOBULAR CLUSTER NGC 6397},
author = {Bogdanov, Slavko and Van den Berg, Maureen and Grindlay, Jonathan E. and Heinke, Craig O. and Cohn, Haldan N. and Lugger, Phyllis M., E-mail: bogdanov@physics.mcgill.c},
abstractNote = {We present a deep Chandra X-ray Observatory study of the peculiar binary radio millisecond pulsar (MSP) PSR J1740-5340 and candidate millisecond pulsars in the globular cluster NGC 6397. The X-rays from PSR J1740-5340 appear to be non-thermal and exhibit variability at the binary period. These properties suggest the presence of a relativistic intrabinary shock formed due to interaction of a relativistic rotation-powered pulsar wind and outflow from the unusual 'red-straggler/sub-subgiant' companion. We find the X-ray source U18 to show similar X-ray and optical properties to those of PSR J1740-5340, making it a strong MSP candidate. It exhibits variability on timescales from hours to years, also consistent with an intrabinary shock origin of its X-ray emission. The unprecedented depth of the X-ray data allows us to conduct a complete census of MSPs in NGC 6397. Based on the properties of the present sample of X-ray-detected MSPs in the Galaxy, we find that NGC 6397 probably hosts no more than six MSPs.},
doi = {10.1088/0004-637X/709/1/241},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 709,
place = {United States},
year = {2010},
month = {1}
}