J/ApJ/736/90 Chandra X-ray sources of NGC 1399 (Paolillo+, 2011)
Probing the GC-LMXB connection in NGC 1399: a wide-field study with the
Hubble Space Telescope and Chandra.
Paolillo M., Puzia T.H., Goudfrooij P., Zepf S.E., Maccarone T.J.,
Kundu A., Fabbiano G., Angelini L.
<Astrophys. J., 736, 90 (2011)>
=2011ApJ...736...90P 2011ApJ...736...90P
ADC_Keywords: Binaries, X-ray ; Clusters, globular ; Galaxies, nearby ;
Photometry, HST ; X-ray sources
Keywords: galaxies: elliptical and lenticular, cD -
galaxies: individual (NGC 1399) - galaxies: star clusters: general -
X-rays: binaries - X-rays: galaxies - X-rays: individual (NGC 1399)
Abstract:
We present a wide-field study of the globular cluster (GC)/low-mass
X-ray binary (LMXB) connection in the giant elliptical NGC 1399. The
large field of view of the Advanced Camera for Surveys/WFC, combined
with Hubble Space Telescope and Chandra high resolution, allow us to
constrain the LMXB formation scenarios in elliptical galaxies. We
confirm that NGC 1399 has the highest LMXB fraction in GCs of all
nearby elliptical galaxies studied so far, even though the exact value
depends on galactocentric distance due to the interplay of a
differential GC versus galaxy light distribution and the GC color
dependence. In fact, LMXBs are preferentially hosted by bright, red
GCs out to >5Reff of the galaxy light. The finding that GCs hosting
LMXBs follow the radial distribution of their parent GC population
argues against the hypothesis that the external dynamical influence of
the galaxy affects the LMXB formation in GCs. On the other hand,
field-LMXBs closely match the host galaxy light, thus indicating that
they are originally formed in situ and not inside GCs. We measure GC
structural parameters, finding that the LMXB formation likelihood is
influenced independently by mass, metallicity, and GC structural
parameters. In particular, the GC central density plays a major role
in predicting which GCs host accreting binaries. Finally, our analysis
shows that LMXBs in GCs are marginally brighter than those in the
field, and in particular the only color-confirmed GC with
LX>1039erg/s shows no variability, which may indicate a
superposition of multiple LMXBs in these systems.
Description:
The optical data were taken with the ACS on board the HST (GO-10129),
in the F606W filter. A detailed description of the HST data and source
catalogs are given in Puzia T.H. et al. 2011, in preparation.
The X-ray data were retrieved from the Chandra public archive (CXC).
We selected observations 319 (ACIS-S; 2000 Jan 18) and 1472 (ACIS-I;
2003 May 26).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 117 230 X-ray source catalog in NGC 1399
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See also:
B/chandra : The Chandra Archive Log (CXC, 1999-2012)
B/hst : HST Archived Exposures Catalog (STScI, 2007)
J/A+A/513/A52 : Velocities of NGC 1399 globular clusters (Schuberth+, 2010)
J/ApJS/192/10 : Chandra ACIS survey in 383 nearby galaxies. I. (Liu, 2011)
J/ApJ/690/512 : LMXBs and globulars in early-type galaxies (Humphrey, 2009)
J/A+A/477/L9 : Globular clusters around NGC 1399 (Schuberth+, 2008)
J/ApJ/662/525 : LMXBs in globular clusters of 5 galaxies (Kundu+, 2007)
J/MNRAS/382/1947 : CT1 photometry in NGC 1399 and NGC 4486 (Forte+, 2007)
J/AJ/127/2114 : Globular clusters around NGC 1399 (Dirsch+, 2004)
J/AJ/105/1762 : Globular clusters around NGC 1399 (Ostrov+ 1993)
http://cxc.harvard.edu/ : Chandra X-ray observatory (CXC) home page
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Source index number
5 I1 h RAh [3] Hour of Right Ascension (J2000) (1)
7- 8 I2 min RAm [38] Minute of Right Ascension (J2000) (1)
10- 13 F4.1 s RAs Second of Right Ascension (J2000) (1)
15 A1 --- DE- [-] Sign of the Declination (J2000)(1)
16- 17 I2 deg DEd [35] Degree of Declination (J2000) (1)
19- 20 I2 arcmin DEm [22/32] Arcminute of Declination (J2000) (1)
22- 25 F4.1 arcsec DEs Arcsecond of Declination (J2000) (1)
27- 32 F6.1 ct NCts [6/3920] Total net 0.5-8keV counts
34- 37 F4.1 ct e_NCts Lower limit uncertainty in NCts
39- 42 F4.1 ct E_NCts Upper limit uncertainty in NCts
44- 49 F6.1 ct/ks/s2 Flux [1/1567] The 0.5-8keV photon flux (10-7ph/s/cm2)
51- 54 F4.1 ct/ks/s2 e_Flux Uncertainty in Flux
56- 60 F5.2 --- HR1 The (0.5-1keV)/(1-2keV) hardness ratio
62- 65 F4.2 --- e_HR1 ? Uncertainty in HR1
67 A1 --- f_HR1 [i] Indicates an infinite HR1 uncertainty
69- 73 F5.2 --- HR2 The (0.5-1keV)/(1-8keV) hardness ratio
75- 78 F4.2 --- e_HR2 ? Uncertainty in HR2
80 A1 --- f_HR2 [i] Indicates an infinite HR2 uncertainty
82 I1 --- Var [0/1] Variability flag, 1=variable (2)
84- 87 F4.2 arcsec Sep [0/8.5] X-ray/optical positions separation (3)
89- 92 F4.1 mag Vmag [15.5/27.9] HST F606V band magnitude
94- 96 F3.1 --- SInd [0/1] SExtractor stellarity index (0=gal 1=star)
98-101 F4.1 mag T1mag ? Ground-based T1 band magnitude
103-107 F5.2 mag C-T1 ? Ground-based (C-T1) color
109-112 F4.1 mag zmag ? ACS z band magnitude
114-117 F4.2 mag g-z ? ACS (g-z) color index
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Note (1): USNO registered coordinates
Note (2): Based on either K-S probability P>95% or flux difference >3σ
between observations #319 and #1472 (1=variable 0=non-variable).
Note (3): Optical position is the closest HST V band counterpart.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 13-Dec-2012