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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];
  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)
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. https://doi.org/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. https://doi.org/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},
url = {https://www.osti.gov/biblio/21392344}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 709,
place = {United States},
year = {2010},
month = {1}
}