Accretion Disk Processes with
Chandra HETG
Accretion Phenomena in Accreting Neutron Stars
From atol to Z-sources
Norbert S. Schulz, L. Ji, M. Nowak
Claude R. Canizares
MIT Kavli Institute for Astrophysics & Space Research
T. Kallman
GSFC, Greenbelt MD
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Atoll-, Banana- and Z-sources
Schulz, Hasinger&Truemper 1989, Hasinger & van der Klis 1989
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Atoll-, Banana- and Z-sources
Schulz, Hasinger&Truemper 1989 sub-L
Eddington accretion rates super-L
Eddington accretion rates
Spectral States of XTE J1701 - 462: Link Between
Z and Atoll Sources (Lin et al. 2010)
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Atoll-sources with Chandra HETG
M. Linares PhD Thesis 2009
1S 0921-63 74.7ks 1
4U 0614+091 200.2 ks 4
4U 0919-54 28.5 ks 1
4U 1254-690 51.6 ks 1
4U 1323-619 39.2 ks 1
4U 1543-62 37,8 ks 1
4U 1608-52 23,8 ks 1
4U 1624-49 73.7 ks 1
4U 1630-47 51.1 ks 1
4U 1636-53 110.1 ks 4
4U 1705-44 59.2 ks 3
4U 1728-34 135.3 ks 4
4U 1735-44 73.7 ks 3
4U 1746-37 41.7 ks 1
4U 1812-12 86.1 ks 1
4U 1820-39 120.0 ks 5
4U 1822-00 2.2 ks 1
4U 1822-37 180.4 ks 3
4U 1857+01 4.9 ks 1
EXO 0749-767 76.4 ks 3
GS 1826-24 164.2ks 3
GR 1915-11 328.4ks 11
Her X-1 245.0ks 10
4U 1730-335 28.7ks 1
Ser X-1 76.8ks 1
XB 1916-05 46.4ks 1
26 Atoll sources for
2.3 Msec in
69 observations
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Accretion of Matter in X-ray Binaries
Spectral continua
~7 8 9 10 11 log r [cm]
Photo-emission and absorption line spectra for log L x
> 37 [erg/s]
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Accretion Disk Morphologies
OpticaLthick cool reflection surface
Thin & hot ionization layer
Accretion disk atmosphere
Accretion disk atmosphere/
Accretion Disk Corona *ADC)
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Accretion Disk Atmospheres log L x
= 38
= 37
Assumptions:
- energy balance between heating by incident radiation and cooling by recombining emission.
- uniform static corona in thermal equilibrium.
Compare:
- the deduced emission measure n 2 V from the measured line luminosity
L line
= n 2 V a atom
E line
A ion with the expected one from an X-ray heated ADC d EM / d x
= 2.5x10
65 x
-3 L
38
2 f(R , T ) yellow: measured quantities blue atomic data and ADC models green : quantities to compare
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

4U 1626-67 (Schulz et al. 2002)
Accretion Disk Coronae
Her X-1 (Ji et al. 2008)
2S 0921-80 (Kallman et al. 2003)
Cir X-1 (Schulz et al. 2008)
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Atoll Sources: 4U 1822-37 with Einstein
White & Holt 1982
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Atoll Sources: 4U 1822-37 with RXTE
White & Holt 1982
Heinz & Nowak 2001
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Atoll Sources: 4U 1822-37 with Chandra
Cottam et al. 2001
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Atoll Sources: 4U 1822-37 with Chandra
Ji et al. 2010
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Atoll Sources: 4U 1822-37 with Chandra
Heinz & Nowak 2001
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Atoll Sources: 4U 1822-37 with Chandra
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Atoll Sources: 4U 1822-37 with Chandra
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Atoll Sources: 4U 0614+091 with Chandra
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Atoll Sources: 4U 0614+091 with Chandra
Schulz 1999, Piraino et al. 1999, Migliari et al. 2010, Schulz et al. 2010
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Atoll Sources: 4U 0614+091 with Chandra
Madej et al. 2010
Schulz et al. 2010
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Atoll Sources: 4U 0614+091 with Chandra
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Banana-sources with Chandra HETG
GX 3+1 9.2 ks 1
GX 13+1 29.9 ks 1
GX 9+9 46.2 ks 1
GX 13+1 150 ks 5
GX 9+9 200 ks 3
3 Banana sources for
85.3 ksec in
4 observations
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Banana Sources: GX 13+1 with Chandra
GX 13+1 (4U 1811-17) is a persistently bright
(F x
= 9x10 -9 erg cm -2 s -1 , N
H
= 10 22 cm -2 ) LMXB with a K5 III companion at distance of 7+/-1 kpc.
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Z-sources with Chandra HETG
Cir X-1 265.4 ks 9
Cyg X-2 258.0 ks 5
GX 17+2 79.9 ks 3
GX 340+0 80.1 ks 4
GX 349+2 51.1 ks 4
GX 5-1 81.8 ks 5
Sco X-1 15.0 ks 1
GX 349+2 130.0 ks 4
7 Z -sources for
831.8 ksec in
31 observations
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Z-source and Microquasar: Cir X-1
(Parkingson et al. 2003)
Fender et al. 2004
Possibly ultra-relativistic jet
Neutron star binary
Low/Intermediate mass companion
Accretion disk wind of 400 -2000 km/s
Variable cool & hot absorbers
Suggested soft ionized absorber
QuickTime™ and a
GIF decompressor are needed to see this picture.
7th Microquasar Workshop, Foca, Sept. 1-6, 2008

Z-sources with Chandra HETG
Church&Church 2001, 2004
Church et al. 2006, 2010
Jackson et L. 2009
Extended ADC model
Cyg X-2 like Z-tracks
Sco X-1 like Z-tracks
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Interpretation of Z-tracks with ExADCs
Church, Jackson,
& Church 2009
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Z-sources: Cyg X-2
Low-mass X-ray Binary:
Z-source prototype
Distance: 8-12 kpc
Luminosity: >> 10 37 erg/s
Companion: A9III evolved, 0.6 M
Sun
Binary period: 9.84 days
Compact Object: Neutron star
(type I bursts)
Spectral Properties
(DiSalvo et al. 2002 )
:
Column Density: 2x10 21 cm -2
Diskbb/bbody : 0.8 keV / 1.7 keV
Electron Temperature: > 3 keV
Comptoniztation (seed): 1-2 keV
Fe-K line: 6.7 keV,
42 eV EW
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Extended ADCs in Z-sources: Cyg X-2 r disk
= [0.7 -- 2.7] x10 10 cm n
Z
= < 10 n fexxv
14
~ 10 16 cm -3 cm -3 log x : 2.8 (HB) --> 3.4 (FB)
L x
: 0.6 L
Edd
--> 1.4 L
Edd
Chandra Accretion Workschop — Cambridge, MA. July 13-15, 2010

Summary
Chandra HETG has observed 36 LMXBs (identified Atoll, Banana, and
Z-Sources) for ~ 3.2 Msec in 104 observations.
The Atoll source 4U 1822 -37 shows a thin ionization layer of ionization parameter log x
< 2.6 inferring L ~ 10 38 erg/s; x
Highly ionized Fe XXVI emission from central corona
The Atoll source 4U 0614+091 is likely of ultra-compact nature with an accretion disk radius of a few 10 9 cm, probable higher Ne abundance.
It exhibits a highly variable and moderately relativistic O VIII line from it inner disk
The Z-source Cyg X-2 exhibits broad line emission indicating the presence of an extended (r~10 10 cm) ADC . Line fluxes indicate ADC heating from
HB --> NB --> FB from sub- to super Eddington luminosities,