Magnetic CVs in the XMM-Newton - PowerPoint Presentation

Presentation on theme: "Magnetic CVs in the XMM-Newton"— Presentation transcript

Slide1

Magnetic CVs in the XMM-Newton Era: the Intermediate Polars D.de Martino INAF-Osservatorio Astronomico di Capodimonte Napoli

&

G.Anzolin

,

J.-M.Bonnet-Bidaud

,

M.Falanga

,

B.Gaensicke

,

F.Haberl

,

N.Masetti

,

G.Matt

,

M.Mouchet

,

K.MukaiSlide2

OutlineOpen questions: Evolutionary link between Polars and IPs Role of MCVs in Population of Galactic

X-ray

Sources

Role

of fundamental parameters in accretion and emission properties

Results from XMM-Newton:

Increased IP membership

New X-ray properties: commonalities with Polars

Slide3

Questions on MCV EvolutionMCVs ~20-25% of all CVs vs MWDs~10% of all WDsRK v.7.10 (2008)~40%~50%Slide4

MCV Class Census: Polars IPs Pre-Rosat 18 (60%) 12 (40%) Post-Rosat 55 (70%) 25 (30%) Today 94 (54%) 78 (46%) Candidates increased by 50% in last 4yrs (see Koji Mukai’s IP Web Site)~80%

~70%

QUESTION

Do

IPs evolve towards synchronism?Do IPs harbour lower B field WDs?Slide5

Polars: Beuermann (2000) IPS: Butters et al. 2009 Systematic Survey in Polarized light still missing!Polarimetric UBVRI survey recently started @ NOT (Katajainen et al. 2007; Butters et al. 2009) Spectropolarimetriy @ ESO/VLT attempted but large

oversubscription!

What about B field strengths in IPs?

V405 Aur

BG CMi

V2400 OphPQ Gem

RXJ2133

RXJ1730

WGA1958

V1223 Sgr

ROLE OF SALT TELESCOPE !

Most IPs lie below synchronization line

On average lower B field systems that may evolve towards synchronism

PolarsSlide6

Wide range of asynchronisms: - Clustering close to Pspin/Porb=0.1 but new optical candidates at high & low degree of asynchronism- 50% of the class still to be confirmed in the X-rays!Do IPs evolve towards synchronism? ConfirmedO CandidatesX This work XMM-Newton

Norton et al. (2004,2008) propose IPs

at Porb>3hrs with

:

B ≥10 MG

will evolve into PolarsB≤10MG evolve into unobservable low-field Polars or B field re-emerges

when

Mdot

decreases

.

To

keep

spin-equilibrium

Pspin

increases

while

Porb

decreases

->

short

Porb

IPs

should be weakly

desynchronized

X-RAY FOLLOW-UPS ON GOING!Slide7

HARD X-RAY MCVs HARD X-RAY SURVEYS ARE CHANGING THE VIEW!INTEGRAL ISGRI: 421 sources (~5% are CVs) SWIFT/BAT: 450 sources (~6% are CVs)Slide8

Common characteristics of hard X-ray CVs?●●●●●

×

Dwarf Nova

●

IP Candidates

○ Confirmed IPs∆ Confirmed Polars∆ Asynchr. Polars▲ Candidate Polar

Confirmed IPs with XMM-Newton

(Haberl et al. 2002;

Staude et al. 2006;

de Martino et al. 2006,2008; Anzolin et al. 2009)

25

INTEGRAL

CVs with

ROSAT

counterpart

INTEGRAL-ROSAT

COLOR DIAGRAM:

Hard spectra with wide range of absorption

Most

RXTE

,

INTEGRAL

&

SWIFT

detected

CVs

are

MCVs

(

Revnistev

et

al. 2004;

Barlow

et

al. 2006;

Bonnet-Bidaud

et

al.2007;

Mukai

et

al.2007;

Bodaghee

et

al. 2007;

Shafter

et

al.

2008,

see also Potter et al. Poster yesterday…….)

MAGNETISM & ASYNCHRONISM

SEEM TO BE

COMMON CHARACTERISTCS

OF HARD X-RAY

CVs

!Slide9

Role of MCVs in Galactic Populations? RXTE & INTEGRAL surveys of Milky Way (Sazonov et al. 2006; Revnivtsev et al. 2006, 2008): XLF [2-10keV] at L<1034erg/s from Coronal

(65%) and CVs (35%)XLF

of CVs [2-12keV]

similar

to XLF[16-60keV] Galactic Ridge emission at E>20keV dominated by MCVs

CHANDRA

Survey

of

Galactic

Center

(

Muno

et

al. 2003;2004;

Ruiter

et

al 2005

):

- 1500

over

2000

Faint

Sources

:

Lx

< 1031 – 1033 erg/s - Hard

spectra: kT > 8keV & Fe H-like and He-like emissions -

Affected by local

absorption

-

Variable

:

Periods

300sec – 4.5hrs

IPs

proposed

to

be

dominant

population

See

also

poster on

Chandra

Survey

of

Galactic Bulge

by Torres et al. (

Tuesday

)

IPs

a

still

hidden

population

of

XRBs

?Slide10

QUESTIONSIPs a still hidden population of Galactic X-ray sources?Confirm IP Membership of CandidatesWhat are the true Polar progenitors? Why most Hard X-ray CVs are asynchronous?Emission properties & fundamental parameters Do all IPs possess a SOFT X-ray component?Hunting for Soft X-ray & Polarized IPs

Characterize spectral components

Sensitive Broad-Band

X-ray

observations are essential! Slide11

Role of XMM-Newton Uninterrupted observations of faint sources :- Secure membership identification- Accretion mode diagnostic

:   Disc  -  

Direct (no disc)

accretion

,-,  Disc

overflow (Hybrid)Energy dependent X-Ray/UV/Optical pulses:

-

Geometry

and

magnetic

field

complexity

-

Sites

of

Primary

&

Reprocessed

radiation

-

Absorption

effects

X-Ray spectra:

- Accretion region diagnostic: Pre-Shock, Post-Shock, WD irradiation

XMM-Newton

observed

20

IPs

:

Confirmed

IP status

for

11

candidates

!

Provided

new

hints

in

emission

propertiesSlide12

X-ray Periodicities Complexities in Energy dependent X-Ray Power SpectraOne Pole disc-fed (de Martino et al. 2005)One Pole Hybrid(Anzolin et al. 2008)

ω

ω

ω

-

ΩSlide13

X-ray Periodicities Complexities in Energy dependent X-Ray Power SpectraTwo Poles disc-fed(de Martino et al. 2008)Two Pole Hybrid(de Martino et al. 2006)ω

ω

-Ω

2

ω

ω

3

ωSlide14

X-ray Pulses Energy dependent structured pulsationsOne hard PoleTwo hard & Soft PolesStronger Soft PolePrimary hard & soft Pole + Secondary soft Pole

See

also

Koji Mukai’s Poster #87 Slide15

X-ray Spectral PropertiesStarting from the simplest case of HT Cam(de Martino et al. 2005)Multi-temperature post-shock flow :EM(T) ≈(T/Tmax)α - kTmax=20keV; α=0.7 Az=0.6- Absorption negligible(de Martino et al. 2005,A&A)

-He-like OVII triplet: no forbidden line -> high density limit ne> 5

x1012cm-3

- OVII/OVIII ratio -> kTmin=

0.3keV- V(OVIII)1000km/s-> Vshock≈Vff/4 Slide16

X-ray Spectral PropertiesComplexities at soft energiesUU Col a Soft ROSAT IPTwo temperatures: kT hot=11 keV kT cool=0.18 keV Az=0.4Black-Body: kTbb=50eVPartial(51%) Dense Absorber: 1.0x1023cm-2

Strong lines OVIII, OVII

OVII/OVIII ratio

-> kT=0.2

keV

(de Martino et al. 2006, A&A)

Multi-temperature plasma often unable to represent spectraSlide17

X-ray Spectral PropertiesRXJ0704+2625 & RXJ1803+4012One temperature: kT hot > 40 keV Black-Body: kTbb=84eVEW (6.4keV) = 140 evTotal Absorber: 1x1020cm-2Partial(35%) Dense Absorber: 2.0x1023cm-2

XMM-Newton

finds new

SOFT X-RAY

IPs

Multi-temperatures: kT max

~30

keV

Black-Body

:

kTbb=95eV

Partial

(

40%

) Dense

Absorber

:

3x10

23

cm

-2

(

Anzolin

et

al. 2008)Slide18

Hard X-ray IPs: a growing family…& …further complexities at soft energiesRXJ1730-0559 a hard IP with a complex Soft spectrumTwo temperatures: kT hot = 55keV kT cool=0.17 keV Az=0.4Black-Body: kTbb=90eVTotal Absorber: 3.6x1021cm-2Partial(56%)

Dense Absorber: 1.4x1023

cm-2

OVII

Absorption edge

@ 0.74keV τ~1.8Reflection: 6.4keV Fe line: EW=110eV (de Martino et al. 2008,A&A)

3rd IP with absorption edge!

(V709 Cas - de Martino et al. 2001;

V1223 Sgr – Mukai et al. 2001)



Warm absorber in IPs

XMM-NEWTON EPIC-pn & MOS

INTEGRAL

IBIS ISGRISlide19

Hard IPs……..a growing familyIGRJ0023+6141 & RXJ2133+5107Two temperatures: kT hot >14 keV kT cool=0.17keV EW (6.4keV) = 100 evTotal Absorber: 2x1021cm-2Partial(36%

) Dense Absorber:

1x1023cm-2

…but NOT all of them have a SOFT BB component

Three

temperatures: kT max = 40 keV kTmed =5

keV

kT

low = 1keV

EW (6.4keV)

= 140

ev

Black-Body

:

kTbb=99eV

Partial

(

45%

) Dense

Absorber

:

1x10

23

cm

-2

(

Anzolin

et

al. 2009, sub)Slide20

SOFT IPs: An emerging class ROSAT: 4 IPs with soft BB similar to Polars (30-60eV)XMM-Newton: Current roster of 13 IPs (42% of class)Characteristics: Heavily absorbed Nh ~ 1023cm-2 BBsBB temperatures over a wider range (30-100eV)Soft-to-Hard

Luminosity ratio lower than

Polars WD spots smaller

for

hotter BBs (f ~10-5-10-6)Polars: Ramsay et al. 04IPs: Haberl et al. 02, de Martino et al. 06,08Evans & Hellier 07Staude et al. 08Anzolin et al. 08, 09

QUESTIONS:

Do

all

IPs

possess

soft BB

component

?

Geometric

factors

may

play a

role

(Evans &

Hellier

2007)

but

not

always

(

Anzolin

et

al. 2008)

High

kT

BB

->

Lx

locally

exceeding

Eddington

What

happens

at

footprints

?

Is

kT

BB

linked

to

Magnetic

Field

Strength

?

Irradiation

by

Cyclotron

&

Bremsstrahlung

?

Absorption dips and BB Slide21

Reprocessing at WD polesBremsstrahlung irradiates small WD spot areas Cyclotron radiation beaming on wide areasBB Temperature is average over spot area(Konig et al. 2006)Hotter BBs for lowest field IPsCooler BBs in higher field IPs (Anzolin et al. 2008)Polarization searches to confirm the hypothesis SOFT IPs: An emerging class

Name

kT

BB (eV)Anzolin et al. 2008,09Mag.Field

(MG)

Butters et al.2009

PQ Gem

48-66

8-21

V405

Aur

65-73

~30

RXJ1730-0559

90-93

>5MG

RXJ2133+51

94-102

>5MG

V2400

Oph

103-107

8-27

A complete

census

needed

to

draw

conclusions

! Slide22

XMM-Newton Changing our view of MCVsIncreasing number of IPs with Soft X-ray BB but with wider Temperature range than PolarsIncreasing number (~33%) of Polars with no Soft X-ray BB (Homer et al. 05; Schmidt et al. 05; Ramsay et al.09; Vogel & Schwope poster yesterday) kTbb 

Mdot/f1/4 

Shifted to the EUV range

This is what believed to occur in most IPs

Reprocessing in MCVs occurs over large range of spot areasTracing different B,mdot parameter space values? Slide23

Why Hard X-ray CVs? Shock temperature related to WD Mass:Mwd ≈ 0.45 (kTshock /20keV) 0.75 Post Shock Region mainly cools via Bremsstrahlung Temperature and Emissivity distrubution in PSR (Suleimanov et al. 2005; 2008)Masses are over-estimated using 1T flow (Saxton et al. 2007)Masses of MCVs not different from non-MCVs Slide24

For B≤ 5-10MG Bremsstrahlung is main cooling 1T and 2T flows predict similar X-ray continua up to 5keV 1T flow is harder above 5keV (Saxton et al. 2007) For B>30MG and low dm/dt Cyclotron is important lowers Shock height and decreases Te Bremsstrahlung flux can be drastically reduced (Fischer & Beuermann 2001) Is asynchronism is a signature of low B systems ? Probably yes for IPs

Why most hard X-ray CVs are asynchronous?

Radiative losses by cyclotron & bremsstrahlung forB>1MG

Frad ≈

ρ

a Te b One-fluid plasma in low B and high flow rates(Wu et al. 1994; Fisher & Beuermann 2001; Beuermann 2003; Saxton et al. 2005; 2007)

10keV

40keV

B=30 MG dm/dt=100,10,1,0.1 g/cm2/s (Fischer & Beuermann 2001)

100

10

1

0.1

IPs and moderately low field Polars with high dm/dt may be hard X-ray sourcesSlide25

What about Hard X-ray Polars?NAMEB (MG)SYNCHROP_orb (hr)V834 Cen23YES

1.7

SwiftJ2319+26?

NO:

3.0

BY Cam 41NO

3.4

V1432

Aql

28-35

NO

3.4

IGR/Swift

J

1453-55

(Potter

et al Poster

on Monday)

INTEGRAL/SWIFT detected POLARS

Could they be high rate accretors?Slide26

Another hard X-ray view of Polars? NAMEB (MG)SYNCHROP_orb (hr)SDSS0155+0029YES

1.45

CE

Gru

32:

YES1.8CD Ind

15

NO

1.8

WW

Hor

15

YES

1.9

V2301

Oph

7

YES

1.9

SDSS1700+36

?

YES

1.9

SDSS0729+36

?

YES

2.5

V349

Pav

?

YES

2.7

XMMJ2250+57

?

YES

2.9

V1500

Cyg

25-50:

NO

3.4

POLARS with Hard X-ray spectra from XMM-Newton

(Ramsay et al. 2004;2009; Homer et al. 2005; Schmidt et al.2005)

Changing our view of MCVs:

Increasing number of

Polars

with no Soft X-ray BB

(see Ramsay et al.

2009; Vogel &

Schwope

poster yesterday)

kTbb



Mdot

/f

1/4



Shifted to the EUV range?

This is what believed to occur in IPs

Increasing number of IPs with Soft X-ray BB but with wider Temperature range

Reprocessing over wide range of spot areas

Hard & Soft MCVs may trace different

B,mdot

parameter space Slide27

ConclusionsIdentification of new MCVs essential to understand :Evolution of MCVsPotential role in Galactic Populations of X-ray sources Role of XMM-Newton

in: Identification of new

faint candidates Study

of

temporal and spectral properties Increasing similarities of IPs with Polars:One or Two-poles active & secondary pole

is

soft

Increasing

number

of

IPs

with

soft BB

but

with

differences

Increasing

Polars

with

no soft BB

We

still need a complete

understanding of MCVs

Role of fundamental parameters (Bwd,Mwd,

Mdot) in emission properties