Chandra observation of the globular cluster NGC 6440 and the nature of cluster X-ray luminosity functions

David Pooley; Walter H.G. Lewin; Frank Vereunt; Lee Homer; Bruce Margon; Bryan M. Gaensler; Victoria M. Kaspi; Jon M. Miller; Derek W. Fox; Michiel Van Der Klis

doi:10.1086/340498

Chandra observation of the globular cluster NGC 6440 and the nature of cluster X-ray luminosity functions

David Pooley, Walter H.G. Lewin, Frank Vereunt, Lee Homer, Bruce Margon, Bryan M. Gaensler, Victoria M. Kaspi, Jon M. Miller, Derek W. Fox, Michiel Van Der Klis

Research output: Contribution to journal › Article › peer-review

63 Scopus citations

Abstract

As part of our campaign to determine the nature of the various source populations of the low-luminosity globular cluster X-ray sources, we have obtained a Chandra X-Ray Observatory ACIS-S3 image of the globular cluster NGC 6440, We detect 24 sources to a limiting luminosity of ∼2 × 10 ³¹ ergs s^-1 (0.5-2.5 keV) inside the cluster's half-mass radius, all of which lie within ∼2 core radii of the cluster center. We also find excess emission in and around the core that could be due to unresolved point sources. Based on X-ray luminosities and colors, we conclude that there are 4-5 likely quiescent low-mass X-ray binaries and that most of the other sources are cataclysmic variables. We compare these results to Chandra results from other globular clusters and find the X-ray luminosity functions differ among the clusters.

Original language	English (US)
Pages (from-to)	184-196
Number of pages	13
Journal	Astrophysical Journal
Volume	573
Issue number	1 I
DOIs	https://doi.org/10.1086/340498
State	Published - Jul 1 2002

All Science Journal Classification (ASJC) codes

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.1086/340498

Cite this

@article{b0e5cfc6674d44939eb6e6c27ab3aae2,

title = "Chandra observation of the globular cluster NGC 6440 and the nature of cluster X-ray luminosity functions",

abstract = "As part of our campaign to determine the nature of the various source populations of the low-luminosity globular cluster X-ray sources, we have obtained a Chandra X-Ray Observatory ACIS-S3 image of the globular cluster NGC 6440, We detect 24 sources to a limiting luminosity of ∼2 × 10 31 ergs s-1 (0.5-2.5 keV) inside the cluster's half-mass radius, all of which lie within ∼2 core radii of the cluster center. We also find excess emission in and around the core that could be due to unresolved point sources. Based on X-ray luminosities and colors, we conclude that there are 4-5 likely quiescent low-mass X-ray binaries and that most of the other sources are cataclysmic variables. We compare these results to Chandra results from other globular clusters and find the X-ray luminosity functions differ among the clusters.",

author = "David Pooley and Lewin, {Walter H.G.} and Frank Vereunt and Lee Homer and Bruce Margon and Gaensler, {Bryan M.} and Kaspi, {Victoria M.} and Miller, {Jon M.} and Fox, {Derek W.} and {Van Der Klis}, Michiel",

year = "2002",

month = jul,

day = "1",

doi = "10.1086/340498",

language = "English (US)",

volume = "573",

pages = "184--196",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "American Astronomical Society",

number = "1 I",

}

TY - JOUR

T1 - Chandra observation of the globular cluster NGC 6440 and the nature of cluster X-ray luminosity functions

AU - Pooley, David

AU - Lewin, Walter H.G.

AU - Vereunt, Frank

AU - Homer, Lee

AU - Margon, Bruce

AU - Gaensler, Bryan M.

AU - Kaspi, Victoria M.

AU - Miller, Jon M.

AU - Fox, Derek W.

AU - Van Der Klis, Michiel

PY - 2002/7/1

Y1 - 2002/7/1

N2 - As part of our campaign to determine the nature of the various source populations of the low-luminosity globular cluster X-ray sources, we have obtained a Chandra X-Ray Observatory ACIS-S3 image of the globular cluster NGC 6440, We detect 24 sources to a limiting luminosity of ∼2 × 10 31 ergs s-1 (0.5-2.5 keV) inside the cluster's half-mass radius, all of which lie within ∼2 core radii of the cluster center. We also find excess emission in and around the core that could be due to unresolved point sources. Based on X-ray luminosities and colors, we conclude that there are 4-5 likely quiescent low-mass X-ray binaries and that most of the other sources are cataclysmic variables. We compare these results to Chandra results from other globular clusters and find the X-ray luminosity functions differ among the clusters.

AB - As part of our campaign to determine the nature of the various source populations of the low-luminosity globular cluster X-ray sources, we have obtained a Chandra X-Ray Observatory ACIS-S3 image of the globular cluster NGC 6440, We detect 24 sources to a limiting luminosity of ∼2 × 10 31 ergs s-1 (0.5-2.5 keV) inside the cluster's half-mass radius, all of which lie within ∼2 core radii of the cluster center. We also find excess emission in and around the core that could be due to unresolved point sources. Based on X-ray luminosities and colors, we conclude that there are 4-5 likely quiescent low-mass X-ray binaries and that most of the other sources are cataclysmic variables. We compare these results to Chandra results from other globular clusters and find the X-ray luminosity functions differ among the clusters.

UR - http://www.scopus.com/inward/record.url?scp=0012415093&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0012415093&partnerID=8YFLogxK

U2 - 10.1086/340498

DO - 10.1086/340498

M3 - Article

AN - SCOPUS:0012415093

SN - 0004-637X

VL - 573

SP - 184

EP - 196

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 1 I

ER -

Chandra observation of the globular cluster NGC 6440 and the nature of cluster X-ray luminosity functions

Abstract

All Science Journal Classification (ASJC) codes

Access to Document

Other files and links

Fingerprint

Cite this