High energy (X-ray) emission from HD 163296

P. Christian Schneider

Hamburger Sternwarte

HAeBe stars workshopSantiago, Chile

April 7th, 2014

Overview

P.C. Schneider 2 / 18

FUV & optical emission from the jet(many photons)

X-ray emission from the jet(a few photons)

X-ray emission from the central component(some photons)

HD 163296

P.C. Schneider 3 / 18

spT: A2, Age: 4 MyrMontesinos et al. (2009)

d = 122 pc van Leeuwen 2007

No detected stellarmagnetic fieldHubrig et al. (2007), Wade et al. (2007),

Alecian et al. (2013)

log Maccr. ∼ −7Mendigutía et al. (2014), Ellerbroek et al.

(2014)

Well-known jet Devine et al.

(2000), Grady et al. (2000)

From Wassell et al. (2006)

The jet in Lyα and in optical lines

P.C. Schneider 4 / 18

STIS long-slit data from 2011: Mout ∼ 10−9M� yr−1

From Günther, Schneider & Li (2013)

. . . and in X-rays!

P.C. Schneider 5 / 18

2003

Adapted from Swartz et al. (2005)

. . . and in X-rays!

P.C. Schneider 5 / 18

2003

Adapted from Swartz et al. (2005)

. . . and from the jet!

P.C. Schneider 6 / 18

Adapted from Günther, Schneider & Li (2013)

From Güdel et al. (2011)

DG Tau

2003

2011

. . . and from the jet!

P.C. Schneider 6 / 18

Adapted from Günther, Schneider & Li (2013)

From Güdel et al. (2011)

DG Tau 2003

2011

. . . and from the jet!

P.C. Schneider 6 / 18

Adapted from Günther, Schneider & Li (2013)

From Güdel et al. (2011)

DG Tau

2003

2011

What does that mean?

P.C. Schneider 7 / 18

Highly significant detection(conf. 97% in 2003, 93% in 2011)

X-rays require T & 3× 106 K

translates to shock velocities of 500 km s−1

Evidence for high shock velocities?“classical” jet tracers indicate vs < 100 km s−1(e.g., Ellerbroek et al. 2014)

→ Look at Lyα

Lyα - Emission from forward & counter-jet

P.C. Schneider 8 / 18

Knot A

Knot B

Knot C

Air

glo

w

400 200 0 200 400Velocity (km s−1 )

10

8

6

4

2

0

2

4

6

8

10D

ista

nce

(arc

sec)

Knots?Knots?

1999

13.4

13.3

13.2

13.1

13.0

12.8

12.6

log(S

urf

ace

bri

ghtn

ess

) [e

rg s−

1 c

m−

2 a

rcse

c−2

−1]

Data from Devine et al. (2000)

Lyα - Emission from forward & counter-jet

P.C. Schneider 9 / 18

Knot A

Knot B

Knot C

Air

glo

w

400 200 0 200 400Velocity (km s−1 )

10

8

6

4

2

0

2

4

6

8

10D

ista

nce

(arc

sec)

Knots?Knots?

2000

13.4

13.3

13.2

13.1

13.0

12.8

12.6

log(S

urf

ace

bri

ghtn

ess

) [e

rg s−

1 c

m−

2 a

rcse

c−2

−1]

Data from Devine et al. (2000)

Lyα - Emission from forward & counter-jet

P.C. Schneider 10 / 18

Air

glo

w

400 200 0 200 400Velocity (km s−1 )

10

8

6

4

2

0

2

4

6

8

10D

ista

nce

(arc

sec)

Knots?Knots?

2011

13.4

13.3

13.2

13.1

13.0

12.8

12.6

log(S

urf

ace

bri

ghtn

ess

) [e

rg s−

1 c

m−

2 a

rcse

c−2

−1]

From Günther, Schneider & Li (2013)

X-ray vs. Lyα emission

P.C. Schneider 11 / 18

1213.0 1213.5 1214.0 1214.5 1215.0 1215.5Wavelength ( )

0.1

0.2

0.3

0.4

0.5Fl

ux (

a.u

.)

Air

glo

wv s f

or

X-r

ays

Lyα emission

600 500 400 300 200 100 0Projected velocity (km/s)

Adapted from Günther, Schneider & Li (2013)

Origin of the X-ray emission?

P.C. Schneider 12 / 18

Bulk velocities too low to explain X-rays

Minimum flow velocity required:ca. 600 km s−1 which implies a launching region closeto 0.1 AU for MHD disk winds

Possibility: Stationary shock at the base of the jet

The central source in X-rays

P.C. Schneider 13 / 18

Adapted from Günther, Schneider & Li (2013)

Stellar X-ray properties of HD 163296

P.C. Schneider 14 / 18

log LX = 29.4Soft spectrum (mean energy 0.5 keV)O VII triplet → soft X-rays come & 2R? above thephotosphere (No signs of accretion)

From Günther & Schmitt (2009)

Non-stellar X-rays in YSOs

P.C. Schneider 15 / 18

Jet driving sources often show particular X-rayspectrum (TAX-sources, Güedel et al. 2007)Prime example: DG TauHowever, no offset in HD 163296 (X-rays within 30 AU)

0.1 0.0 0.1 0.2 0.3Offset (")

0.25

0.20

0.15

0.10

0.05

0.00

Off

set

(")

2004

2005

2006

2010

N

EDG Tau

Forward jet

direction

Centroid of the soft inner X-ray component

60

50

40

30

20

10

0

Dis

tance

(A

U)

Adapted from Schneider & Schmitt (2008)

Conclusions I

P.C. Schneider 16 / 18

Non-stellar, but “central” X-ray component

10 % of the jet mass loss required to powerX-ray emission (10−10 vs. 10−9M� yr−1)

X-ray properties similar to (some) CTTS→ X-rays related to innermost jet component→ Similar magnetic jet launching mechanism

X-rays from HD 163296 in context

P.C. Schneider 17 / 18

From Stelzer et al. (2009)

X-rays from HD 163296 in context

P.C. Schneider 17 / 18

From Stelzer et al. (2009)

X-rays from HD 163296 in context

P.C. Schneider 17 / 18

HD 163296

From Stelzer et al. (2009)

Conclusions II

P.C. Schneider 18 / 18

No unique X-ray emission mechanism in HAeBe stars

HD 163296 is among the X-ray brightest HAeBe stars

Outflow emission probably represents an additional X-raygenerating process

Comparison with CTTS→ Jet launching probably similar even for the highestvelocities